Control and power module for integrated alternator-starter

Field of the Invention

p0001The invention relates to a rotating and reversible electric machine such as an alternator-starter, in particular intended on the one hand, to supply power to the onboard network of a motor vehicle and to charge the battery of the vehicle and secondly to start the engine of the motor vehicle. The invention relates more particularly to a control and power module for controlling such a machine.

PRIOR ART

p0002In a motor vehicle, the alternator converts a rotational movement of the inductor rotor, driven by the thermal engine of the vehicle, an electric current induced in the stator windings. The alternator may also be reversible and constitute an electric motor, or rotating electrical machine for driving in rotation, via the rotor shaft, the engine of the vehicle. This reversible alternator is called an alternator-starter, or alternator-starter. It converts mechanical energy into electrical energy and vice versa. Thus, an alternator-starter can start the engine of the motor vehicle, or, operate in motor mode to drive the motor vehicle. Generally, the stator has three windings, so that the generator is of three-phase type. Alternatively, the alternator is of the six-phase type and can be wound with conductor bars forming pins. When the alternator-starter working in starter mode or in motor mode, it must transmit to the engine a very high torque.

p0003This polyphase and reversible type of machine thus operates as an alternator, in particular, charge the vehicle battery and starter motor to drive the internal combustion engine, also called heat engine of the motor vehicle to start it.

p0004To this end, a power unit connected to the phases of the armature of the alternator, is used as command bridge of the phases in motor mode and acts as a rectifier bridge when the starter-generator is operating in alternator mode.

p0005The <figref idrefs="f0014">Figure 20</figref> shows a rotary electrical machine forming alternator-starter according to the prior art, as disclosed in <patcit id="pcit0001" dnum="WO0169762A"><text>WO 01/69762</text></patcit>.

p0006In this figure, the right side corresponds to the front of the machine and the left side at the rear of the machine. This rotary machine forming alternator comprises:<ul><li>a rotor 743 constituting the coiled inductor conventionally associated with two slip rings 706, 707 and two brushes by which is supplied the excitation current;</li><li>a polyphase stator 503 carrying several coils or windings, constituting the armature 507, which are connected in star or delta in the most frequent case of a three-phase structure, and which deliver to the rectifier bridge, generator operation, the electric power converted.</li></ul>

p0007The bridge is connected to the various phases of the armature and is connected between ground and a supply terminal of the battery. This bridge has, for example, diodes associated with MOSFET transistors.

p0008Motor operation mode such an alternator is carried out by, for instance, a continuous current in the inductor and supplying synchronously, on the stator phases, signals out of phase of 120 °, but ideally sinusoidal optionally trapezoidal or square.

p0009This bridge rectifier in alternator mode, and control in motor mode, is controlled by a control unit. The power unit constituted by the bridge rectifier and control, and the control unit is a control and power module mounted on the outside of the rotary electric machine to which it is connected by a connecting means the electrical output terminals of the stator phases.

p0010There is further provided means for monitoring the angular position of the rotor, in electric motor mode, injecting at the right time of electric current in the winding of the stator.

p0011These means, preferably of the magnetic type, send information to the control unit and are described for example in documents <patcit id="pcit0002" dnum="FR2807231"><text>FR-2807231</text></patcit> and <patcit id="pcit0003" dnum="FR2806223"><text>FR 2806223</text></patcit>.

p0012These means therefore comprise a target 750 wedged in rotation on the rotor or the pulley 701 of the machine and at least one sensor 752 of the Hall type or magnetoresistive detecting the passage of the target, preferably of the magnetic type.

p0013Preferably, at least three sensors 752 are provided, these being carried by the front bearing 713 and rear 504 which the rotating electric machine for supporting fixedly the stator and rotatably the rotor.

p0014The sensor holder 753, here plastic, has portions 755 axially oriented. These portions 755 through the bearing 504 to favor here a hole 754. The sensors 752 are integral with the portions 755 and are located radially between the target 750 and the blades 505 being very close to the target 750. The sensor holder is mounted on a fixing bolt 757.

p0015The electrical connections of the sensors 752 are housed in the sensor holder 753 fixed with two ears 756 on the bottom of the rear bearing 504 on the opposite side to the target 750 and the rotor 743.

p0016The brush holder 716 is fixed on the same face of the bottom of the rear bearing plate 504 using bolts not referenced and ears.

p0017The brush holder 716 comprises in known manner two cages for guiding brushes each cooperating with a slip ring 706, 707 attached to the rear end of the shaft 502. The brushes are subjected to the action of springs housed in the cages.

p0018Is desired in some cases, improve the starting performance of an alternator-starter. Thus, it is possible to excite the rotor for more torque at startup.

p0019This excitation may be achieved by an overvoltage at the terminals of the excitation winding and / or overcurrent in the excitation coil relative to a conventional alternator.

p0020This can be achieved using an electronic booster overexcited the rotor winding only in the starting mode.

p0021This machine has here a conventional alternator structure, for example, of the type disclosed in <patcit id="pcit0004" dnum="EP0515259A"><text>EP-A-0515259</text></patcit> which should be referred for further details.

p0022The pole pieces 741, 742 have holes for passage strength of the shaft 502. More specifically, the shaft 502 is harder than the pole wheels 741, 742 for fixing them by his molletées portions.

p0023This shaft 502 extends on either side of the rotor 743 and form a subassembly therewith.

p0024The magnet wheels, via their flange are fastener, here by electric welding, each fan 515 with blades 505.

p0025This machine is therefore to internal ventilation (air cooled), the rotor carrying at least at one of its axial ends a fan 515. In a variant the machine is cooled by water.

p0026More precisely, the rotor is a claw-pole rotor 743 with pole pieces 741, 742 carrying at their outer periphery axially oriented teeth and a trapezoidal shape. The teeth of a polar wheel are directed towards the teeth of the other polar wheel, said generally trapezoidal shaped teeth being interleaved manner between one pole of wheel to another.

p0027Of course, as described for example in document <patcit id="pcit0005" dnum="FR2793085A"><text>FR-A-2793085</text></patcit>, Permanent magnets may be interposed between the teeth of the rotors to increase the magnetic field.

p0028The rotor carries an excitation winding between the flanges of its pole wheels. This coil comprises an electrically conductive element which is wound with turns of training. This winding is an excitation coil which, when activated, magnetizes the rotor to create, with the teeth of the magnetic poles. The ends of the rotor winding are each connected to a slip ring on each of which rubs a brush. The brushes are carried by a brush holder secured to the rear bearing of the machine centrally carrying a ball bearing rotatably supporting the rear end of the shaft carrying the rotor in joining.

p0029The front end of the shaft is rotatably supported by a ball bearing 711 carried by the front bearing 713 of the machine. The front end of the shaft outside the machine a pulley 701 belonging to a movement transmission device comprising at least one belt engaged with the pulley. The motion transmitting device establishes a connection between the pulley and an element, such as another pulley, driven in rotation by the internal combustion engine of the vehicle.

p0030Furthermore a rear cover 511 is mounted on the rear bearing 504, in particular to protect the brush holder, so that said tracking means are better protected, and easier to implement.

p0031When the machine - here an alternator-starter - functions in alternator mode, that is to say as an electric generator, the pulley 701 is rotated by the internal combustion engine of the vehicle via at least the above-mentioned belt. When the machine is operating in starter mode, that is to say as an electric motor, the pulley rotates the motor vehicle via the belt.

p0032The front and rear bearings, perforated for the internal ventilation of the machine, are interconnected, for example by using tie rods 527, and part of the support of the machine for attachment to a fixed part of the vehicle. This support fixedly carries at its outer periphery the stator usually constituted by a stack of laminations 508 with notches for mounting coils or more generally of the stator windings whose outputs are connected to the bridge rectifier and said control.

p0033The coils or stator windings are formed by son or bars windings as described for example in document <patcit id="pcit0006" dnum="WO9206527A"><text>WO92 / 06527</text></patcit>; the bars may be of rectangular section.

p0034The stator surrounds the rotor, which brushes are connected to an alternator regulator to maintain the voltage of the alternator at a desired voltage, for example of the order of 14V for a 12V battery.

p0035The control and power module and the controller are here mounted in an electronic package mounted on the outside of the rotary electrical machine. The controller can also be integrated into the control and power module control unit that is implanted outside. This casing carries switching means, comprising power switches, a control unit and an excitation circuit. The excitation circuit is active in boot mode to maximize the starting torque of the alternator-starter and start more easily the internal combustion engine, also called heat engine of the motor vehicle or during a cold start, or when restarting after such a stop at a red light, the engine having been cut to reduce the fuel consumption and achieve a so-called "stop and Go".

p0036This overexcitation circuit receives as input the on-board network voltage delivered by the battery and / or alternator, and delivers to the terminals of the excitation coil a voltage exceeding this voltage onboard network.

p0037The controller may include means which, if the alternator-starter would discharge on-board network being disconnected from the battery (if "load dump" according to English terminology generally used by the skilled person) to immediately order the opening of a power switch that powers the excitation coil, to achieve rapid demagnetization of the generator, including its rotor.

p0038Currently, it is conventional to provide a power unit in which the bridge rectifier has power transistors connected to form a bridge of switches, and wherein the transistors are controlled in synchronism with the current in an armature winding of the alternator (synchronous rectification). However, it is necessary to control the transistors by means of a relatively sophisticated control unit such as, for example, a microcontroller, current probes detecting the direction of current in the windings of the armature of the alternator, a bridge image, etc. One of these rectifier bridges is described in patent application<patcit id="pcit0007" dnum="FR2806553A"><text>FR-A-2806553</text></patcit>. This bridge rectifier is shown in<figref idrefs="f0001">figure 1</figref>. It has three branches B1, B2, B3 of at least two transistors each, each connected between one phase of the alternator starter φ1, φ2, φ3, Ua supply the on-board network and ground GND. Each transistor T1 to T6 is controlled by a control unit U1 to U6. These control units U1 to U6 together form the power unit control unit formed by the bridge switches. Each of these control units is provided for comparing an alternator phase voltage with a reference voltage and for controlling one of the transistors of the rectifier bridge, according to the result of the comparison. Each of these control units has separate means from other units and provided to perform, separately from the other units, comparison and compensation for variations in its reference voltage, so that each unit requires no signal those having same variation as the phase voltage and as those having same variation as its reference voltage. Each control unit U1 to U6 controls a power transistor T1 to T6.

p0039This control unit, as most of the known control units currently requires a large number of electronic components since it requires a control unit transistor of the rectifier bridge.

p0040The components used to make the power unit are therefore positioned and connected on a first circuit board and form the power stage.

p0041The components used to make the control unit are placed and connected on a second circuit board.

p0042The two electronic boards, forming the control and power module, are connected together by electrical son. However, the electrical connection of these two cards requires a large number of connections between the two stages. Consequently, the control and power module is relatively bulky, which requires placing it in a separate housing unit containing the electromechanical starter-alternator set.

p0043Thus, unlike conventional alternators which are fully integrated in a single housing, the alternator starter requires two units, namely a housing with the starter-alternator itself and a housing containing the control and power module. An alternator-starter thus requires a footprint than a conventional alternator. Moreover, it leads to the user, a further establishment of difficulty, in the motor vehicle, for that is the automaker to connect the two housings together.

p0044Furthermore, it is known by <patcit id="pcit0008" dnum="EP1134886A"><text>EP1134886</text></patcit>, <patcit id="pcit0009" dnum="EP0357183A"><text>EP0357183</text></patcit> and <patcit id="pcit0010" dnum="EP0660501A"><text>EP0660501</text></patcit> applicable devices in the technical field of the invention.

p0045The document <patcit id="pcit0011" dnum="EP1134886A"><text>EP1134886</text></patcit> discloses a voltage rectification device for a motor vehicle alternator. This device comprises a switching bridge equipped with modules which compare a phase voltage of the alternator to a reference voltage and controls one of the switches according to the result of the comparison. The voltage rectifier device includes comparators and amplifiers to compensate for the effects of variations of a reference voltage. Each module includes voltage compensators which are different for each module.

p0046The document <patcit id="pcit0012" dnum="EP0357183A"><text>EP0357183</text></patcit> discloses a device and a control method using a rotary electric machine coupled to the thermal engine of a vehicle for filling engine start functions and electric generator. An electronic control unit takes into account the battery voltage and the speed of the electrical machine in order to maintain constant voltage reports / frequency determined during start-up operations and electrical generation. Three circuits of attack called "drivers" are provided to respectively control the three branches of a switching bridge.

p0047The document <patcit id="pcit0013" dnum="EP0660501A"><text>EP0660501</text></patcit> addresses a vehicle alternator-starter. The starter-alternator includes a converter comprising several power MOSFETs. The converter is connected between the stator windings and a vehicle storage battery. Drivers of so-called "drivers" and a control unit are also provided. The MOSFET power transistors, the converter, the driving circuits and the control module are integrated in a single module.

Disclosure of Invention

p0048The invention is precisely to remedy the drawbacks of the techniques described above. To this end, the invention provides a control module and power miniaturized and can be integrated in the housing of the alternator-starter.

p0049More specifically, the invention relates to a control and power module of an alternator-starter for a motor vehicle as defined by claim 1.

BRIEF DESCRIPTION OF FIGURES

p0050<ul><li>The <figref idrefs="f0001">figure 1</figref>, Already described, is a schematic representation of a control and power module according to the prior art.</li><li>The <figref idrefs="f0002">2</figref> represents a control and power module according to the invention.</li><li>The <figref idrefs="f0002">3</figref> represents the various connections of a driver in the invention control unit.</li><li>The <figref idrefs="f0003">4</figref> shows the electrical connections between a driver and the transistors of the power unit which it controls.</li><li>The <figref idrefs="f0004">5</figref> represents a mode of integration of the control and power module of the invention, in the back of an alternator-starter housing.</li><li>The <figref idrefs="f0005">6</figref> shows an elevational view of an embodiment of a power module according to the invention.</li><li>The <figref idrefs="f0006">7</figref> is a view in section along the line <figref idrefs="f0005">6</figref>.</li><li>The <figref idrefs="f0006">8</figref> is a sectional view of the embodiment of a power module according to another embodiment.</li><li>The <figref idrefs="f0007">Figures 9 to 11</figref> represent a way of connecting to the mass of the embodiments corresponding to <figref idrefs="f0005 f0006">Figures 6 to 8</figref>.</li><li>The <figref idrefs="f0008">Figure 12</figref> and another embodiment of the invention.</li><li>The <figref idrefs="f0009">13</figref> is a sectional view of a rear bearing comprising the power electronics modules of the invention.</li><li>The <figref idrefs="f0010">Figure 14</figref> shows an example of fan used in the <figref idrefs="f0009">13</figref>.</li><li>The <figref idrefs="f0011">Figures 15, 16, 17 and 17a</figref> show connection mode the outputs of the electronic modules conducted at cover.</li><li>The <figref idrefs="f0012">figures 18</figref> and <figref idrefs="f0013">19</figref> show a rear axial view of the cap of the electrical machine.</li><li>The <figref idrefs="f0014">Figure 20</figref> shows a starter generator according to the prior art.</li><li>The <figref idrefs="f0015">figures 21</figref> and <figref idrefs="f0016">22</figref> show an exemplary embodiment of the modules illustrated in <figref idrefs="f0006">figures 7</figref> and <figref idrefs="f0008">12</figref>.</li><li>The <figref idrefs="f0017">Figure 23</figref> is a sectional view of the <figref idrefs="f0008">Figure 12</figref>.</li></ul>

Detailed description of embodiments of the invention.

p0051In the figures, identical or similar elements will be represented by the same reference signs. Ua referenced board voltage can be called a B +.

p0052The <figref idrefs="f0002">2</figref> represents the control and power module 100 of the invention, connected to the alternator-starter. More specifically, this<figref idrefs="f0002">2</figref> shows a 3-phase alternator-starter which each φ1 phase φ2 and φ3 is connected to one of the branches, respectively B1, B2, B3 of the power unit 1. Each of the three branches of the rectifier bridge or order constituting the 1 power unit are identical. Consequently, only the branch B1 will be described in detail later.

p0053The branch B1 of the rectifier bridge 1 includes two switches 11 and 12, which in the invention, are power transistors. The transistor is the transistor 11 "high side" of the branch B1. It is connected between the φ1 phase of the alternator-starter and supply Ua from the vehicle network. The transistor is the transistor 12 "low side" of the branch B1. It is connected between the φ1 phase of the alternator-starter and the ground line GND.

p0054The control and power module includes a control unit 50 comprising firstly, drivers 10, 20, 30, each driving the power transistors in the same branch and advantageously these drivers compare potential φ1 phase φ2, φ3 of the alternator-starter with the ground potential of the rectifier bridge for the control of transistor 12 and with the output potential Ua of the rectifier bridge for controlling the transistor 11, and secondly, a management circuit 2 drivers 10, 20 and 30.

p0055The branches of the rectifier bridge and the drivers that drive them form a first stage 100b of the module of the invention. The management circuit 2 forms a second stage 100a.

p0056The driver 10 is connected at its output to the gates of two transistors 11 and 12. The driver 10 is itself connected, by its input to the management circuit 2.

p0057Each driver 10, 20 and 30 is controlled by the same control circuit 2. For this each driver receives as input various signals from the management circuit 2. These signals are shown in <figref idrefs="f0002">3</figref>.

p0058These signals are divided into two categories:<ul><li>signals indicated on the left of the driver: these are signals from the management circuit; and</li><li>signals indicated on the right of the driver: these are received or transmitted to the power unit signals, that is to say to the transistors that driver.</li></ul>

p0059One of the signals received from the management circuit is the boost supply, named ALG, which is the supply voltage provided by an auxiliary source to the gates of transistors 11 and 12. The driver also receives, from the management circuit of SC sensor signals which is information provided by the position sensors of the rotor of the alternator-starter to indicate position of the rotor of the rotating electrical machine. The control circuit also supplies the VD driver a validation information from starter mode and a VA validation information of the alternator mode. These last two signals, the driver whether the starter-alternator has to work at a specific moment, as an alternator or as a starter.

p0060On this <figref idrefs="f0002">3</figref>, Also shows the signals received and transmitted to the power unit, that is to say to the transistors 11 and 12 of the rectifier bridge. The driver receives the supply potential Ua of the alternator-starter, namely the potential of the on-board network supply. It also receives information MUa which is the measurement input of the potential of this line Ua. The driver outputs a signal GHS which is the control gate of the power transistor 11. The signal driver also receives input from PH phase from the alternator starter, and the potential of MPH measure of phase input. The driver also outputs the GLS controlling the gate of the power transistor 12. Finally, the driver receives the ground potential GND and the extent MGND ground potential.

p0061On the <figref idrefs="f0003">4</figref>There is shown a driver 10, 20, 30 of the control and power module 100 of the invention, with its various components and its various connections. On this<figref idrefs="f0003">4</figref>The alternator-starter 3 supplies a phase signal φ1 to the low side and high side transistors 12 11 and into PH driver. It also supplies the phase measurement to the driver 10 on its input MPH.

p0062On this <figref idrefs="f0003">4</figref>, Entries measures MPH MGND and MUA have been shown to the left of the driver to a simple question of simplification of the figure. In practice, as shown in<figref idrefs="f0002">3</figref>These three inputs are placed on the right side of the driver, that is to say on the side of the power unit.

p0063The transistor 12 is connected to ground GND and into MGND the driver. The transistor 11 is connected to the Vout voltage line and to the input MUa the driver.

p0064Two comparator C11 and C12 are respectively connected between inputs and MUa MPH and between the inputs MPH MGND the driver. The output signal of the comparator C11 provides a comparison value between the value of the phase MPH and the value of the reference voltage MUa. The output of the comparator C12 provides a comparison value between the value of the phase MPH and the value of the MGND mass. These comparison values ​​are then digitally processed by a logic circuit 13 to deduce if the gate of transistor 11 and / or the gate of transistor 12 must be charged and / or discharged. The G11 and G12 grids respective power transistors 11 and 12 are charged and discharged by current sources, respectively, S11 and S12. The current sources S11 are performed, for example, from two transistors SHC and SHD. The current sources S12 are performed, for example, from two transistors SLC and SLD. Thus, each transistor constitutes a current source.

p0065ALG input is high potential, issued by the management circuit 2 to load properly the grid of the power transistors 11 and 12, through the current sources S11 and S12. This potential ALG can be, for example: ALG = Ua + 16V

p0066Driver operation of the <figref idrefs="f0003">4</figref> is: in starter mode, position sensors, placed on the rotor of the alternator-starter working in synchronous machine, mark the position of the rotor. The sensor signals are transmitted to the management circuit 2 which processes and applies them to the inputs SC of the drivers. Grids G11 and G12 of the transistors 11 and 12 are controlled based on signals received on the input SC, via the logic circuit 13 and the current sources S11 and S12.

p0067In alternator mode, the power transistors 11 and 12 operate in synchronous rectification, that is to say the comparators C11 and C12 detect the phase level on the input MPH with respect to ground potential on the input MGND and the output potential of the input MUa. The result of this comparison is applied to the gates G11 and G12 through the logic circuit 13 and the current sources S11 and S12.

p0068The alternator or starter mode is selected on the driver by the respective logic inputs VA and VD. For example, when the alternator mode is selected, the input VA receives a logic signal 1 and input VD a signal at 0. And conversely when the starter mode is selected. The logic level 1 is, for example, a voltage of 5 volts and the logic level 0 a zero voltage.

p0069The inputs of measurements phase MPH, potential MUa and MGND mass can prevent the effects of disturbances created by the currents flowing in the connections PH, Ua and GND. Such disturbances may be caused, for example, by the resistance of connections between components to each other or on the substrate of the electronic card.

p0070Each driver is located near the potentials PH, VA, GND to be measured, the measurement inputs MPH, MVA, MGND use connections of reduced length, which diminishes the sensitivity of these inputs relative to disturbances that can pass through these connections which further justifies the proposed architecture of the invention.

p0071For cons, the management circuit 2 can be removed from the drivers because it transmits only slightly critical potentials (ALG supply, logic levels VA, VD, SC) as opposed to measuring inputs (MPH, MVA, MGND).

p0072The gates of transistors 11 and 12 must be brought to potentials above the potential Ua output of the alternator-starter. For this purpose, the control circuit delivers on the terminal ALG a voltage Ua + 16V, +/- 1 which provides power to the G11 and G12 transistor gates 11 and 12. If the voltage at the terminal ALG is not sufficient, then the power transistors 11 and 12 are open.

p0073The operation of the control and power module 100 of the invention will now be described. In idle mode, that is to say when the vehicle is stopped and the ignition key is open (that is to say, not turned in the lock of the ignition switch), then the transistor 11 is opened while the transistor 12 is closed. This condition is obtained when the logic inputs VD and VA are both at 0. When the vehicle engine is off and the ignition key is opened, the management circuit 2 is inactive and can not deliver the voltage Ua + 16 volts on the input ALG of the driver. Accordingly, G12 is applied to the gate of the transistor 12 a voltage whose minimum value is Ua - 1 volt.

p0074In other words, when the key is open and VD and VA are 0, then the transistor 11 gate voltage is less than or equal to 0.2 volts and the gate voltage of transistor 12 is greater than Vout - 1 volts. In other words, the transistor 12 is closed while the transistor 11 is open, thereby maintaining the potential of the stator to the ground potential.

p0075The current consumed by the driver under these conditions is less than 10 microamperes at 25 ° C.

p0076When the vehicle is stopped and you turn the ignition key in the lock of the ignition switch (that is to say the ignition key is closed) then this causes the circuit startup 2. This control management circuit 2 is then active and can deliver the voltage Ua + 16V on the input ALG of the driver. Under these conditions, the G11 gate potential of the transistor 12 is limited to 15 +/- 1 volt. In other words, when the key is closed and VD and VA are 0, then the transistor gate voltage 11 remains less than or equal to 0.2 volts and the transistor gate voltage 12 is equal to 15 +/- 1 volts.

p0077In starter mode, VD and VA validation of the entries are no longer both at 0. The starter mode also involves the input of the SC sensor signal. Thus, in starter mode, the rectifier bridge functions as an inverter. Each branch of the rectifier bridge is synchronized with the sensor signal SC applied to the corresponding driver. The mode of inverter operation is obtained when VD is at 1 and the input VA is 0.

p0078Thus, if CS = 0 and VA = 0 and RV = 1, then the grid voltage G11 of the transistor 11 is less than 0.2 volts and the grid voltage G12 of transistor 12 is equal to 15 +/- 1 volt. Conversely, if SC = 1 and VA = 0 and RV = 1, then the grid voltage G11 of the transistor 11 is equal to 15 +/- 1 volt and the grid voltage G12 of transistor 12 is less than 0.2 volts . The control circuit and power 100 then operates as an inverter, the applied voltages that Ph1 phases, Ph2 and Ph3 being linked to the rotor position based on SC1 signals SC2 and SC3 delivered by the after treatment position sensors by the management circuit 2.

p0079In alternator mode, the rectifier bridge works in synchronous rectification. This function is activated when the enable input VA is at 1 while the VD input is 0. In this case, the comparators C11 and C12 of the driver compare, on the one hand, the phase voltage to the voltage PH Ua and, secondly, the phase voltage PH to the ground potential GND. The result of the comparison is used to open and / or close the transistors 11 and 12 in synchronism with the currents flowing in the armature windings of the alternator-starter. The effect on the gates of transistors 11 and 12 is the following:<ul><li>If PH> Ua and VD = 0 and VA = 1 then the grid voltage G11 of the transistor 11 is equal to 15 +/- 1 volt and the grid voltage G12 of transistor 12 is less than 0.2 volts, and accordingly : the transistor 11 is closed and the transistor 12 open.</li><li>If Vout> PH> GND and VD = 0 and VA = 1 then the grid voltage G11 of the transistor 11 is less than 0.2 volts and the grid voltage G12 of transistor 12 is also less than 0.2 volt, and Therefore: the transistor 11 and 12 are closed.</li><li>If GND> PH and RV = 0 and VA = 1, then the grid voltage G11 of the transistor 11 is less than 0.2 volts and the grid voltage G12 of the transistor 12 is 15 volts +/- 1 and therefore: the transistor 12 is closed and the transistor 11 open.</li></ul>

p0080In classic mode recovery, the control circuit 2 may control the opening of all power transistors 11, 12, 21, 22, 31 and 32 of the rectifier bridge to eliminate the synchronous rectification. This mode of operation is obtained when both enable inputs VD and VA are at logic level 1. The adjustment is then performed by the own diode to the MOS transistor technology.

p0081In this case, when VD = 1 and VA = 1 then the grid voltage G11 of the transistor 11 and the grid voltage G12 of transistor 12 are each lower than 0.2 volt.

p0082The gate voltages of the power transistors 11 and 12 are controlled by constant current sources, not shown in the figure for simplification. The control of the closure is achieved by a gate charge current of 100 milliamps, for example, and the control of the opening by a discharge current of 400 milliamperes gate, for example.

p0083On the <figref idrefs="f0004">5</figref>Depicts an example of integration of the control and power module of the invention, in the back of an alternator-starter. Indeed, the fact of using a single driver to control the two transistors of the same branch of the rectifier bridge reduces the number of connections to the management unit 2.

p0084In particular, the driver is constructed so that, on one side, it comprises only connections up to the power unit and, on the other hand, only connections up to the management circuit 2. this way, the driver can easily be connected close to the power transistors which it controls. Furthermore, in this embodiment, only four connections are required between a driver and the management circuit 2, three of these four connections being more common to all drivers. It is therefore easy to separate the management circuit 2 drivers. The size of the management circuit 2 resulting from this separation is thus very much reduced. The management circuit 2 can be integrated in another vehicle equipment.

p0085In the example of <figref idrefs="f0004">5</figref>The control and power module 100 is integrated into the back of the alternator-starter. On the<figref idrefs="f0004">5</figref>We see the back of an alternator-starter with its phase outputs and its rotor. In the case of this<figref idrefs="f0004">5</figref>Each driver is positioned in the vicinity of the power transistors that control, all being located near one of the phase outputs of the alternator-starter. For example, the driver 10 is connected right next to the transistors 11 and 12 of the branch B1 of the rectifier bridge, all transistors and driver being located close to the φ1 phase output of the alternator-starter. Similarly, the driver 20 and the transistors 21 and 22 of the branch B2 of the rectifier bridge are placed next to the φ2 phase output and the driver 30 and the transistors of the B3 branch are placed next to the φ3 output the alternator-starter.

p0086In the example of <figref idrefs="f0004">5</figref>Each branch of the rectifier bridge has several transistors high side and low side several transistors. Indeed, as is conventionally the case, a plurality of transistors (often 2 to 4) are connected in parallel so as to form a larger power transistor. That there is only one power transistor or several transistors connected in parallel, the operation is identical to the one just described.

p0087The end of the shaft 4 (shown schematically by a circle on the <figref idrefs="f0004">5</figref>) Which carries the rotor of the rotary electric machine 5 includes position sensors which provide information on the position of the rotor to the management circuit 2. The rotor position information is processed by the control circuit 2 and then transmitted to inputs SC drivers 10, 20 and 30.

p0088Advantageously, the connections made between the management unit 2 and the various drivers form an arc positioned around the shaft 4 carrying the rotor.

p0089In the case of <figref idrefs="f0004">5</figref>The control and power module 100 is integrated into the housing of the alternator-starter. This set can also be integrated into another vehicle equipment, such as the battery charge management unit.

p0090It is also possible to incorporate only the power unit with its drivers 10, 20, 30 respectively and place the management circuit 2 in an outer casing to the alternator-starter. For example, the management circuit 2 can be integrated into the battery case or in the battery management unit or in the consumer control unit (body control).

p0091In another embodiment, the control and power module 100 is integrated in a separate housing outside the alternator-starter but more compact than in the prior art.

p0092The <figref idrefs="f0005">6</figref> illustrates an embodiment of the first stage 100b of a control and power module 100 of the invention. As described above, this first stage comprises for each of the rectifier arms, each corresponding to a phase of the stator, a driver 10 for measuring and control and the two power transistors. Thus, if we consider a first rectifying bridge arm or control we have the driver 10 and the two power transistors 11 and 12 described above.

p0093According to the invention, this first stage of control and power is advantageously carried out in an independent housing. The three bridge arms are identical, it is possible to use an identical power control to each of the bridge arms.

p0094As shown in <figref idrefs="f0005">6</figref>, Which shows a first stage of control and power module according to an elevation view, the electronic power components 11 and 12 are placed on metal traces 104.

p0095Advantageously, the technology used is the chip deferral technology called bare chip or wherein the component having no protective housing is directly fixed on a support. Indeed, this electronic unit under the bonnet of the motor vehicle is subjected to high thermal stress and must avoid using components in plastic housing. Advantageously, it is best to use components in metal enclosure or components mounted in a technology called chip transfer in which the component is transferred to a metal trace. The network obtained by all the metal traces is called the lead-frame.

p0096To control the phases of the winding of the electrical machine as a starter, it is necessary to inject very high currents. These current can reach a value of about 1000 Ampere when the device operates in a traditional board network voltage of about 12 volts. Thus, the low-side transistor and high-side 11 and 12 may be constituted by the parallel connection of at least two power transistors respectively 11a, 11b and 12a, 12b.

p0097Advantageously, the power module 100b includes a thermistor 102 (temperature sensor) accessible by links TH1, TH2.

p0098The driver 10 is subjected to temperatures well below that at present the power transistors. It is the same for the constituents traces the control signals or measurement ALG, SC, VD, GLS, GHS, TH ... the previously described features.

p0099Ordering a starter-alternator involving very high currents, numerous design issues facing the art to achieve a compact control and able to distribute current and temperature balanced in of the module.

p0100Thus, according to the invention, each module corresponding to a bridge arm, is connected to each phase and operates independently without being traversed by the currents from the other modules. Thus the trace carrying the Ua output is connected to one place at a power conductor that gathers streams from all modules. Each module thus works independently without being crossed or disturbed by the currents relative to the other modules. On the other hand, the power transistors 11a and 12a are advantageously assembled in a perfectly symmetrical manner on the metal trace with respect to the φ1 phase input. We thus obtain a perfectly balanced current distribution. Similarly to power high-side transistors 12a and 12b, they are mounted on their metallic track of symmetrically as possible for the same reasons. This is very important not to unbalance the currents in the power transistors that need to work in parallel with identical currents. Thus, to obtain a power module balanced running of the invention and as shown in<figref idrefs="f0005">6</figref>, The power transistors low-side and high-side are mounted substantially perpendicular to the ways relative to each other. This configuration has the additional advantage to realize all connections by wire bonding without any covering over traces of any signal or power. Thus, all connections are made with the conductors 101 of short length which has the advantages of obtaining a reliable modulus particularly resistant to vibration. Indeed, the automotive environment is vibrating, and the son of bonding connections are subjected to strong vibrations which can break off and contribute to disfonctionnemnet alternator-starter system. The minimization of the length of these connection son increases their resonant frequency which makes them insensitive to vibrations applied to the power module.

p0101As stated previously, an object of the invention is to place an order for compact alternator-starter with a big cooling power while providing high reliability of operation over time.

p0102To achieve such power module capable of circulating currents may rise to about 1000 amperes, the prior art offers some solutions.

p0103The power module could be implemented according to the technology known DBC substrate type (for "Direct Bounded Copper"), which has three layers. A first layer consists of an engraved metal traces forming the connections of an electrical circuit, a second intermediate layer is a plate of electrically insulating material such as a ceramic, e.g., aluminum oxide, and a third layer is a metal plate of copper or of nickel plated copper. Thus a sandwich-copper copper-alumina structure.

p0104The assembly consisting of the DBC substrate type and electronic components soldered or glued power is in turn soldered to a copper plate, forming and heat sink mechanical support. In this technology, traces of copper have a small thickness so as to pass high current, it is necessary to considerably increase the surface traces increasing strongly clutter power module. In addition, this technology is not applicable to applications involving high currents because the thermal capacity offered by the small thickness of the copper is not sufficient. On the other hand, it is very difficult to produce particular shapes, such as rounded shapes that are particularly suitable for integration with applications such as for example the back of a rotating electric machine due to the fragility alumina. On the other hand, alumina is very resistant to vibrations, such as those present within an engine block of the motor vehicle.

p0105The substrate can also be of SMI (Insulated Metal Substrate). In this case, the ceramic plate is replaced by a resin plate, which can support a first layer consisting of a metal track of very thin copper. The third layer of heat dissipation can in this case be constituted by a metal plate of aluminum or copper.

p0106In case the substrate used is a DBC substrate type, the power module is robust and supports a high power but has a high cost. In the case of an IMS-type substrate, the cut-out metal trace may be more complex and can have a greater number of power electronic components thereon, but the module is less resistant to high power and constraints 'harsh environment. However, it is possible in IMS technology to add an additional copper interface interposed between the chip and the metallic track of thin copper to allow for better heat dissipation. This solution is complex to implement, is unsatisfactory from an economic point of view

p0107In both cases, the thermal path between the power electronic components and cooling means external to the power module is long since it requires to traverse at least the numerous layers of the substrate that comprise these two technologies.

p0108The invention aims to remedy the drawbacks of conventional power modules, providing a power module whose manufacture is cheap, and the structure allows efficient cooling using external cooling means and the low number of 'thermal interfaces to cross.

p0109Thus as shown in <figref idrefs="f0006">7</figref> the power module includes metallic power tracks 104 for receiving such power components 11a and 11b canceled as the phase output of the stator winding of the electrical machine. This same metal trace can also carry a thermistor 102 to enjoy the module temperature. This power module, as previously described may include other metallic power tracks 104. Thus, as shown in<figref idrefs="f0006">7</figref>Another metallic power track carries the power component 12 connected to the output + Ua in our embodiment.

p0110Advantageously, these metallic tracks are formed from the same conductive metal plate wherein the metal tracks are for example made by stamping. Advantageously, and to obtain a compact module of the invention, the metal traces made of the metal plate, preferably of copper, is thick for the passage of strong currents. Thus, the thickness of these tracks may vary between 0.6 mm and 2 mm. The aforementioned conventional techniques do not provide traces of such a thickness within the substrate itself. Indeed the thicknesses usually used for the production of trace hardly exceeds 400μm thick. For obvious reasons it is not possible to carry traces of such thickness by conventional engraving operations.

p0111To ensure proper positioning of the tracks with respect to each other, metal bridges are formed during the stamping operation. Obviously, these metallic bridges will be removed in an operation to be carried deshunting end of the process.

p0112Advantageously to simplify the realization of this power module, the metal traces underpowered for example to control signals can also be made from this metal plate thick, their positioning being also carried by metal bridges. All these metallic tracks constitutes the leadframe.

p0113To obtain a leadframe having good mechanical cohesion, it is necessary to arrange it with a device for forming a support. In addition, this support must be able to efficiently evacuate the heat emitted by the passage of strong currents. Thus according to the invention, it is proposed to inject a resin 107 in the free spaces between the metal traces. This can be easily accomplished by placing the lead frame between two plates constituting the mold for injection. Thus, at the end of the injection operation of the resin all the interstices between the tracks are occupied by the resin. The deshunting operation can be performed after this operation.

p0114Advantageously, this resin will be thermoplastic such as PPS (polyphenylene sulfide) or PA 6.6 (polyamide 6.6) or PBT (polybutylene terephthalate). The PPS also has the advantage of being non-flammable (standard UL94V0).

p0115To increase the mechanical cohesion of the support formed by the lead frame and resin molds may include openings so that the resin covers the metal traces locally on a small portion 140 as seen in <figref idrefs="f0006">8</figref>. In the same vein, the edges of metal traces can present particular shapes, such as a bevel 141 to ensure better anchorage of the resin.

p0116After the operation of deshunting, components, including the power components can be secured to the metal tracks such as by brazing in a heating method by laser or oven (convection or infrared). This allows solder electrical and thermal contact between the component and the metallic track.

p0117Thus according to the invention, and as illustrated in <figref idrefs="f0006">8</figref>, One obtains an electronic power module in which the metal tracks on the particular power components 117 are accessible from the outside through the opposite faces 114 to those carrying said components.

p0118The support of the power module according to the invention is realized in that at least the metallic power tracks are partly accessible on their upper and lower faces, the upper face being intended to receive the electronic power component and the lower face 114 for cooperating with a cooling device such that the heatsink 113 illustrated in <figref idrefs="f0006">7</figref>. Advantageously, the parts of the undersides of metal traces are accessible to the right of the components of powers they carry on their upper opposite sides for proper cooling of said components of puisssance.

p0119To ensure good thermal contact between the sides 114 and the top surface 115 of the heat sink 113 is provided to a member 108 advantageously elastic thermally conductive and electrically non-conductive to firstly remove the heat well, and the other hand, to electrically isolate the metal traces between them. Such an element may for example be a glass fabric impregnated with an epoxy resin or polyamide (ITV) or a thermally conductive thermoplastic resin phase change. A thermally conductive material and electrically insulating having two adhesive faces, or a thermally conductive adhesive 108 comprising glass beads forming spacers may also be suitable. The phase change resin has the advantage of flowing under the action of heat. So that the radiator or the underside of the power module has unevenness, so this phase change resin is adapted to seal these irregularities. Advantageously, traces caused to exit the module to communicate with the outside advantageously has a bend 118 facing the top of the module so as to keep them away from the upper surface 115 of the sink 113.

p0120Such a module corresponding to each of the bridge arms may need to be manufactured in very large quantities. In this case, it will have a very high mechanical cohesion while maintaining its heat dissipation ability. Thus, as shown in<figref idrefs="f0006">7</figref>It is expected to be placed under the power module a metal plate 109 forming a base at ground potential. This seat is held in an insulating housing 110, preferably made by overmolding. For mechanical reasons, this belt is advantageously performed with PPS. A cover is fixed on the belt for the same reasons is also made of PPS.

p0121This cap is fixed for example by means of screws 119 that penetrate the belt 110. In other embodiments, the cover can be fixed for example by gluing or welding means such as ultrasonic welding or by friction .

p0122Inside the power module under the hood of the power module 105, a fill material 120 may be deposited to fill the spaces around the electronic components and between wired connections for example of wire bonding. This material 120 filling in addition to its sealing function, has the advantage of strengthening the mechanical cohesion of the support formed by metal tracks and the resin surrounding them.

p0123In the embodiment illustrated in <figref idrefs="f0006">7</figref> an electrically insulating and heat conducting is placed between the metal base 109 and the underside 114 of the metallic tracks. As previously described in<figref idrefs="f0006">8</figref> this electrical insulator 108 can be thermally TVI or a thermally conductive thermoplastic resin phase change. Advantageously, this insulation is glued on both sides, first the side of the metal traces and secondly on the side of the metal base 109. Thus, this base provides effective protection against metal traces and thus makes it possible obtain a good mechanical cohesion and easy handling module.

p0124This base 109 is made of a thermally conductive material and is part of the heat sink element in contact with the lower face 114 of the metallic trace to be cooled.

p0125As seen in <figref idrefs="f0006">7</figref> a finger 106, advantageously derived from material of the protective cap 105, bears against at least one metallic track. In case a filler material 120 is introduced above the electronic components, then the filler material is placed around the finger.

p0126This finger contributes firstly to ensure good mechanical cohesion of the assembly of the power module by forming a rigid module, and secondly, this finger, which comes in pressure against the metal trace at the fixing the cover for example by screwing, causes a slight bulging of the lower face 121 of the metal base 122 of the power module.

p0127Thus according to the invention, this bulging of the bottom face 122 of the power module also contributes to good draining- heat to the heatsink. Indeed, when the power module is fixed for example by screwing on the heatsink 113 at the screw holes 111 while the bulging under the pressure screw ensures perfect plating of the power module against the sink 113 providing element makes good electrical contact between the base 109 and the heat sink 113. the screw hole 111 passing according to one embodiment through a hole 112 in the base, can also be achieved by molding for its upper part for PPS resist screwing efforts.

p0128Alternatively, a thermally conductive material such as TVI, can be placed between the radiator and the power module. In this case, the ground connection will be through an electrical connection means, such as a terminal, connecting the base 109 at the recess 112 to the connector cover, this means for example passing through a hole 606 cover. Obviously, this terminal is electrically isolated from the heat sink 113.

p0129Alternatively, the finger 106 may be replaced by a wall or portion of wall on a part molded traces during the molding operation of the belt 110. Of course, the height of this wall is determined so that the cover fixing operation 105 exerts sufficient pressure on the wall to cause slight bulging of the base 109.

p0130The power components 11 and 11b are connected between the ground is the output phase of the stator winding. In starter mode, they carry very high currents. The ground connections must be as short as possible to limit overheating. One solution would be for example to bring ground pads in the belt 110 and the connection to perform these pads. However, the length of the son is quite long.

p0131Another visible solution on <figref idrefs="f0006">7</figref> is to reach the ground directly from the metal plate 109 forming a base.

p0132In a first embodiment as seen in <figref idrefs="f0007">Figure 9 and 10</figref>, Bosses 123 are formed on the base. These bosses are intended to receive the connection son 126 for the formation of the power circuit. These connections are advantageously of wire bonding. When carrying out molding of the resin at metallic traces, must of course provide for recesses 124 without resin to allow the passage of the studs or boss 123 upward. Similarly, the insulator 108, such as the aforementioned TVI, will advantageously be pre-cut to be positioned around the pads 123. Such a configuration has the advantage of having short length son connection.

p0133Alternatively and as illustrated in <figref idrefs="f0007">11</figref>An opening in the resin 107 and the insulator 108 is formed so as to reach the metal base 109 constituting the mass. This solution eliminates the bosses 123.

p0134The <figref idrefs="f0008">Figure 12</figref> illustrates an embodiment of a power module 250 for alternator-starter that integrates all the power electronics of the three bridge arms control and rectifying circuit of the alternator-starter. Thus the reference 200 represents a power sub-module. This sub-module corresponds to the power electronics of a bridge arm dedicated to a phase output of the stator winding of the electrical machine. The lead frame of each of these submodules corresponds for example to that described in<figref idrefs="f0005">6</figref>.

p0135This embodiment has the advantage of being economical on the one hand, in number of parts to be placed on the cooling device, and on the other hand, in terms of disposal assembly.

p0136Advantageously, each of these sub-modules is separated by a partition 201. The partition 201 and the peripheral belt 110 are advantageously made during the same molding operation. Advantageously, these walls and this belt pads contain connections 202 and 203. As seen in<figref idrefs="f0006">figures 7</figref> and <figref idrefs="f0008">12</figref>, The pads 203 facing the top of the module are divided into pads 203a mass in pad 203b of B + and Vout corresponding to the voltage of the vehicle network and 203c pads for signals of low power. The pads 202 are oriented metallic power tracks 104 and 130. These control pads 202 are connected to the aforementioned metal traces by wire bonds of wire bonding. To connect the metallic power tracks to the corresponding pads 202, is expected to more wired connections in parallel to carry the current without overheating.

p0137The 205 power terminals are directly connected to phase outputs son of the stator winding. This stud 205 is subjected to strong vibrations during operation of the rotating electrical machine. The wire connections 204 which connect the pad 205 via the corresponding pad 202 is a mechanical and thermal coupling with the power sub-module that helps to increase the reliability of the power module.

p0138These pads 202 open upwardly in order to be accessible at the pads 203. Advantageously, the pads 202 and 203 are made directly from the metal traces comprising the lead frame of the electronic module. These metal traces being thick, the pads 203 will present good rigidity facilitating their placement for an external connection, eg by means of a cover 511 comprising metal traces.

p0139Such a module can be attached directly to an external heatsink 13.

p0140In a first assembly, it is envisaged that, for example by screwing, the belt 110 is 201 partitions on the external heatsink. In the three zones dedicated to each of sub-modules 200, is deposited on the external thermal sink interface and non-conductive. Advantageously, this interface 108 consists of an adhesive comprising glass beads, the glass beads acting as a spacer to ensure a constant thickness between the top face of the dissipator and the power sub-modules. then deposited on this glue the support formed by the lead frame and the resin themoplastique corresponding to each of these sub-modules. Obviously any other thermal and electrically insulating interface, such as TVI or double sided adhesive tape may also be suitable. According to one embodiment, this support corresponds to the one described in<figref idrefs="f0006">8</figref> except that it does not include the molded belt 110. In this embodiment, the metallic power tracks 104 are in direct contact with the cooling device through the thermal interface which helps good evacuation heat as a result of small number of thermal interfaces to cross. Alternatively, it may also be considered to stick a subassembly as described in<figref idrefs="f0006">Figures 7 or 8</figref>.

p0141Advantageously, each of these sub-modules is tested before it is assembled on the external cooling device.

p0142When the sub-modules are mounted on the external cooling device wired connections is performed 204 between metal traces 104, 130 and the interconnect pads 202.

p0143At this stage of the power module assembly process, preferably covers each of these sub-module of a gel 120 for guaranteeing the seal chips and connections to humidity and external pollution.

p0144A cap 105 is finally applied against the upper part of the belt 110. At the right of the pads 203, the cap has apertures so that these pads 203 through the cover for the connection with the power signals (phase outputs, or network edge + Ua) or with the control signals from the control unit 2.

p0145Such an arrangement corresponding to the <figref idrefs="f0008">Figure 12</figref> is visible in section in <figref idrefs="f0017">Figure 23</figref>.

p0146The power module 250 as shown in <figref idrefs="f0008">Figure 12</figref> has a rectangular shape. Of course, this module may be in the form of half a circular arc to fit for example to the rear of a rotary electrical machine. It is possible to make this circular form with the technology of realization of the power lead frame described above.

p0147As seen in <figref idrefs="f0008">Figure 12</figref>The power module 250 provides an isolated mass accessible by 203a blocks located in the belt 110. The advantage of this isolated ground is justified especially when switching high currents that disrupt the masses of other electrical equipment. For each bridge arm, there may be one or more ground pads 203a. Advantageously, as the 203b block of B +, use a single ground pad 203a to properly balance the currents. In this case the two ground pads 202a will be connected in the molding belt to make the connection as close to the transistors and a single ground pad 203a released outward.

p0148This preferential assembly mode where we just set previously tested modules (bridge arm) has the advantage of being very economical in terms of waste compared to a process in which it would have to be soldered in a single pass all fleas forming all three bridge arms.

p0149In the case or the heat sink is electrically insulated from the rear bearing, the dissipator an isolated mass which connects to the battery ground directly or via the vehicle chassis. In this configuration and in the second embodiment of including electronics in a single power module as seen in<figref idrefs="f0008">Figure 12</figref>, The pads 202a and 203a masses are removed and are replaced by connections to ground similar to those described in <figref idrefs="f0007">Figures 9 to 11</figref> and in which it will be replaced by the base 109, the upper face of the heat sink 113.

p0150The <figref idrefs="f0009">13</figref> shows a side view in section of the rear of an alternator-starter with integrated electronics comprising an arrangement of the electronic control and recovery according to the invention. As all known starter-alternators, starter-alternator shown<figref idrefs="f0009">13</figref> comprises a rotor 743 fixed on a rotation shaft 502. The rotor 743 is surrounded by a stator 503 provided with an armature winding 507. The stator 503 is supported by the rear bearing 504 and the front bearing (not shown) which maintains the rotation shaft 502 via bearings 506.

p0151As explained above, the alternator-starter comprises a rectifier bridge with MOS power transistors associated with the control units of these power transistors. This rectifier bridge and the control units together form the power electronics of the alternator-starter. The power electronics are mounted on the upper face of a heat sink in bridge 113, one or more power modules 100b previously described.

p0152Advantageously, 100a module containing the control unit 2 is also mounted on the upper surface of the sink for cooling. This control unit 2 advantageously comprises a control circuit for managing the one hand the start modes restart function starter and secondly voltage regulation according alternator. This unit may also include the excitation stage of the rotor winding, which also requires good cooling.

p0153According to the invention, to properly cool the power modules 100b made of one or more modules, the side axially facing the rear bearing of the electric machine of this heat dissipating bridge 113 forms a wall of a longitudinal passage, or radial , flow 517 of coolant into the alternator-starter. The other wall of the passage 517 is formed by the upper face of the rear bearing 504. The lower face of the heat sink 113 includes fins 518 which form ventilation channels 517.

p0154A protective cover 511 has radial apertures 519 advantageously located opposite the flow passage 517. In this way, the cooling fluid, particularly air, is introduced into the rear of the alternator-starter by these openings 519 and then flows through the passage 517 under the sink deck 113, thereby cooling module 100b power electronics and 100a module. A fan 515 carrying the blades 505 fixed to the rotation shaft 502 or the rotor 743, provides the suction of the air within the passage 517.

p0155For more efficient cooling, the fan 515 may advantageously consist of a double superimposed fan including at least one blade of a first fan is positioned between at least two blades of a second fan as seen in <figref idrefs="f0010">Figure 14</figref>. Thus, as shown in<figref idrefs="f0010">Figure 14</figref>The fan 515 comprises according to the invention at least two fans 515a, 515b, called hereinafter first fan and second fan respectively. The second blower 515b is designed to be fixed, for example in known manner by spot welding or riveting, on the axial end 530 (the end face) concerned of the pole wheel 742 of the rotor 743 of the<figref idrefs="f0009">13</figref>.

p0156Here the fans 515a, 515b are being economically metal sheet. Each fan comprises a flange portion 515c respectively, substantially circular plane which is provided with a circular central aperture 515D for the passage of the rotor shaft 502, and a series of projecting fan blades axially relative to the flange 515c and forming therebetween ventilation channels, which in this embodiment are divergent outwards.

p0157The first fan 515a has a first set of blades, said primary blades 515e, while the second fan 515b has a second set of blades, said secondary blades 515f.

p0158Thus, advantageously at least two consecutive blades of a fan is located at least one blade of the other fan.

p0159The primary blades 515e are in one embodiment radially shorter than the secondary blades 515f.

p0160The blades 515e and 515f have substantially the same radial length, the same shape and the same axial height so that these blades are globalement- identical except 515g of two primary blades which are radially shorter than the other blades 515e.

p0161The blades 515e, 515f and 515g are located at the outer periphery of the flange 515c concerned.

p0162The primary blades 515e and 515g are arranged here between each two secondary blades 515f.

p0163This arrangement increases the power of the fan and reduces the risk of detachment of the cooling air stream with respect to the blades. Indeed if the air off of the secondary blades 515f, the primary blades 515e, 515g authorize an air reattachment on the secondary blades 515f. Thus each primary blade 515e and 515g is disposed, that is to say operates in the 515H ventilation channel formed between the two adjacent secondary blades 515f and that widens from the inner periphery to the outer periphery of the blades . In this embodiment at least one primary blade is thus interposed between two consecutive secondary blades.

p0164The primary blades 515e, 515f and 515g are secondary here obtained by cutting and bending from their respective metal flange 515c and advantageously have a curved shape.

p0165And the diverging channels are defined partly by the outer periphery of one of the flanges and by the blades.

p0166Primary and secondary blades have radially a large length and are therefore very efficient as regards ventilation. Advantageously, the blades 515e, 515f and 515g have radially longer than their axial height.

p0167Alternatively the blades are flat being oriented radially, the fan is centrifugal. Alternatively the blades are inclined relative to an axial direction and / or radial. Alternatively the blades are axially higher than long radially.

p0168The flange 515c present here at its outer periphery inclined portions cut advantageously economically to the press, which becomes after bending out of the plane of the flange 515c blades curved here. More specifically the blades have radially sectional shape of a circular arc.

p0169The primary blades 515e are intended to reduce the noise of the electrical machine while increasing throughput and yield. Implantation is made so that the primary blade compresses the cooling fluid so that it is in contact with the secondary blades 515f. The recirculation of the air and the eddies are thus prevented and the flow of air is laminar and is done with little friction and noise. This provision allows if necessary to remove the front fan (not shown) carried by the front polar wheel of the rotor so that the present alternator variant into one fan.

p0170Of course, one could also consider different combinations of provisions of secondary blades 515f with the primary blades 515e and 515g. Thus, it could have several primary blades between the secondary blades. The number of primary vanes disposed between the secondary blades, in a same ventilation device 515 may be constant or variable. Here there is arranged a secondary vane between two adjacent secondary blades, that is to say a row.

p0171Also, you can consider having several consecutive secondary blades 515f devoid of primary blades between them.

p0172The distribution of primary and secondary blades is determined as a function of the electrical machine to be cooled to obtain better cooling with minimal aerodynamic noise.

p0173The primary blades 515e can be distributed angularly in a regular or, as in the case shown in <figref idrefs="f0010">Figure 14</figref>, Irregularly. The irregular arrangement is obtained alternatively by having some blades of different length as the other blades of 515g<figref idrefs="f0010">Figure 14</figref>.

p0174The irregular arrangement enables to further reduce the fans operating noise. It is the same for secondary blades 515f which may have an irregular angular distribution as represents the<figref idrefs="f0009">13</figref>. Thus, we get a series of irregular blades divided into two parts at a rate of one part per fan.

p0175Alternatively a thermal insulation means, such as a thermally insulating coating, intervenes between the two flanges 515c of the first and second fans, the first fan 515a can be in this case plastic reinforced with fibers. The blades 515e, 515f and 515g extend axially in the same direction perpendicular to the plane of the flange 515c.

p0176Alternatively the blades may be inclined and curved relative to the plane of the flange in question as described in <patcit id="pcit0014" dnum="FR2602925A"><text>FR A 2602925</text></patcit>.

p0177An angular indexing means reached between the two flanges 515c for good angular position and therefore good orientation of primary blades relative to the secondary blades. To do this each flange 515c has at its inner periphery a notch 515k. The 515k slots are identical here. So just superimpose the notches for example, using a gauge to obtain the correct angular position. Then fixed together fans for example by welding or riveting to form a handleable and transportable assembly.

p0178Advantageously, the first flange has at least one recess, such as a hole or a notch shown in broken lines in 515m for fixing the second flange for example by welding or riveting on the rotor of the machine. Preferably several holes or notches are provided.

p0179Alternatively each flange is fixed for example by welding on the rotor.

p0180It will be appreciated that the blades 515e, 515f and 515g are all here axially at the same height that is to say that the free edges of the blades are in the same transverse plane. More specifically the blades 515e and 515g have axially a height lower than the blades 515f, the difference in width being equal to the thickness of the first flange 515c.

p0181Alternatively the blades 515e, 515f are axially different heights, the blades 515f extending for example in axial projection with respect to the blades 515e, 515g. It follows that the free edges of the blades are not all in the same plane.

p0182In all cases it is possible to set a 515P lid on the free edge of the blades 515e, 515f and 515g or the most remote free edges of the plate 515c as the <figref idrefs="f0011">Figure 16</figref> of the document <patcit id="pcit0015" dnum="FR2811156A"><text>FR A 2811156</text></patcit> and as shown partially in dotted lines in <figref idrefs="f0010">Figure 14</figref>.

p0183Alternatively at least one blade of one of the fans has, overhanging a fin extending obliquely or perpendicular to the plane of the flange of the fan concerned as described and visible in <figref idrefs="f0007 f0008 f0009">Figures 11 to 13</figref> of the document <patcit id="pcit0016" dnum="FR2811156A"><text>FR A 2811156</text></patcit>. Generally with the invention can be obtained the same configurations with two sets of blades of different sizes in the document<patcit id="pcit0017" dnum="FR2811156A"><text>FR A 2811156</text></patcit> cited in a simple and economical manner. For example at least one blade and preferably at least some of the blades, at least one of the fans may be corrugated or be axially decreasing height or be flat and inclined relative to a radial direction respectively as in the<figref idrefs="f0005">figures 6</figref>, <figref idrefs="f0011">15</figref> and <figref idrefs="f0002">2</figref> of this document.

p0184With this ventilation device 515 is decreased the pressure losses and noise, it increases the efficiency and the air flow is obtained and a stable flow of the cooling fluid thus providing an effective cooling of the power and control modules 100a and 100b. Thus, a ventilation device with complex configurations of blades conferring an increased cooling power, at a cost of relatively low cost while having a good mechanical strength.

p0185For more information, refer to the patent application <patcit id="pcit0018" dnum="FR0302425"><text>FR 03 02425 filed February 27, 2003</text></patcit>.

p0186Well done, the sink deck 113 forms a mezzanine above the rear bearing 504.

p0187According to the invention, the sink deck 113 has, on its underside, cooling fins 518. These cooling fins are arranged in the passage 517 and provide the flow of cooling fluid along a selected path, that is ie so that the fluid penetrates closer to the rotation shaft to lick at best the underside of the sink deck. And the underside of the sink deck is advantageously cooled over the entire radial distance between the outer periphery and the inner periphery close to the shaft of the sink deck. Adjacent fins form radial channels guiding the cooling fluid in the passageway 517. Thus, these channels have a lower surface formed by the rear bearing, both sides next to two adjacent fins and the U-bottom of the dissipator bridge formed between two adjacent fins.

p0188Advantageously, the heat sink 113 comprising on its lower face 113b of the fins 518, and on its upper face 113a the / control modules and power 100a, 100b is a single piece. Alternatively, the heatsink 113 100b carrying the power modules is assembled on a blade arrangement thereby forming a sink deck into two parts.

p0189This fluid is then evacuated through vents 504a -504d formed in the rear bearing plate 504. These openings 504a - 504d are preferably identical to those achieved in an alternator bearing, like that shown in <figref idrefs="f0014">Figure 20</figref>. Advantageously, the fins 518 are arranged radially in the direction of flow of the fluid concentrating to 504b and 504c of the central vents rear bearing 504.

p0190Thus, the air (or other cooling fluid) is laterally sucked into the starter-alternator and flows to the central vents 504b and 504c of the bearing 504 while licking the dissipating elements, that is to say, the fins 518 over their entire length before discharge through the side openings 504a and 504d of the bearing 504. Thus, 100b power electronics is cooled by conduction and convection, after cooling of the sink deck 113, through the fins 518 .

p0191Moreover, as the sink deck 113 and the power modules 100b are not pressed against the rotation shaft, there is advantageously between this rotating shaft 502 and the sink deck 113, a space 522 through which air may also circulate. This space 522 forms an axial channel of fluid flow. According to one embodiment of the invention 523a and 523b openings are made in the hood of protection 511. Air is then drawn through these openings 523a and 523b in the alternator-starter, then flows through the space 522 along the rotation shaft 502 and joins the flow passage 517 in the sink deck 113 which helps to improve the cooling of the heat sink 113. in this way, power electronics is cooled, a hand, laterally through the passage 517 and, secondly, axially with the space 522. This additional axial air flow passing through the space 522 also allows to obtain a better cooling of the internal parts of the alternator, such as the cage brush or the coil ends of the armature windings, an increase in the overall air flow in the machine.

p0192The path of flow of cooling fluid to the rear of the alternator-starter is shown by arrows F and dotted lines, on the <figref idrefs="f0009">13</figref>.

p0193According to a preferred embodiment of the invention, the deflectors 524 are placed downstream of the vents 504a and 504d formed in the rear bearing 504. These baffles 524 will drive off the inlet fluid flow of the outflow of fluid so that out of the alternator starter fluid is not immediately reintroduced into the passage 17. This prevents significant recirculation of hot fluid from inside the alternator-starter.

p0194These deflectors 524 can be fixed on the bearing 504, near the side openings 504a and 504d of the bearing. They can also be made in the protective cover 511, for example, by raising the ends of the protective cover, as shown in<figref idrefs="f0009">13</figref>.

p0195In the embodiment of the invention shown in <figref idrefs="f0009">13</figref>The protective cover 511 covering the entire back of the alternator starter, that is to say that the envelope power electronics 100b, 100a mounted on the dissipater bridge 113 and the entire rear bearing 504 . in this case, the protective cover 511 may include vents located downstream of the side vents and the rear bearing for leave to drain the fluid out of the alternator-starter. It can also comprise, in addition to or instead of these gills of baffles 524. These can be made in the lid itself.

p0196The protective cover 511 may also wrap the power electronics mounted on the sink deck and the upper bearing part 504, that is to say it does not involve the lateral sides of the bearing having the vents 504a and 504d. In this case, the baffles can be attached to the bearing 504 or realized by raising the end of the hood.

p0197As shown in <figref idrefs="f0009">13</figref>, The fan door 515 at the axial end of at least a portion of these blades 505 a 515P lid. This cover causes the air flow F to pass the level of the blades 505 of the fan which thus promotes a better cooling of the coil ends of the stator winding 507 and electronics carried by the sink.

p0198Advantageously, the outer edge 525 of hearing 504b and 504d formed in the rear bearing 504 is substantially in the inner edge of the blades 505 so as to pass all the coolant flow F between the blades 505 of the fan. Thus, only a residual flow can pass between the top of the hood 515P and the axial underside of the rear bearing 504.

p0199Advantageously, the vents 504b and 504d are close to the bearing housing 506 so that it can be efficiently cooled and so much more if the fan consists of the superposition of two fans as described previously.

p0200According to a first embodiment, and as seen in <figref idrefs="f0009">13</figref>The heatsink 113 is electrically insulated from the rear bearing 504. Thus, the heat sink 113 is an isolated ground for such power electronics contained in the / 100b modules electronics management unit 2. Electrically isolate the heatsink the rear bearing contributes to better performance in terms of electromagnetic compatibility and thermal.

p0201According to a first variant embodiment the sink deck 113 is secured to the rear bearing plate 504 by means of electrically insulated tie assembly 527 and advantageously thermally non-conductive and constituting a thermal barrier from the heat from the stator.

p0202Advantageously, the tie rods 527 are the same as those usually used to fix the housing 504 with the magnetic circuit 508 of the stator 503. An electrically insulating washer 527B is interposed between the lock nut 527a and the upper face 113a of the heat sink 113. 527c spacer having a shoulder 527D is interposed between the lower face 113b of the heat sink and the axial outer face of the rear bearing 504.

p0203In a second embodiment, the heatsink 113 is secured to the rear bearing plate 504 in an electrically insulated manner by means of a screw 528 whose head is oriented on the side of the axial lower side of the bearing 504. In this embodiment a spacer electrically not condutrice 528a is placed between the lower face 113b of the heat sink 113 and the upper axial face of the rear bearing plate 504. the screw 528 comes into abutment against an electrically insulating shoulder gun placed within the axial thickness of the rear bearing 504.

p0204Obviously, other sink securing means on the bearing can be considered.

p0205Obviously, the spacers 528a or 527c can be secured to the sink deck 113 or the bearing 504 to form bonding pads. In this case, the electrical and thermal insulating means such as grommets to be placed at the end of these bonding pads.

p0206The heat sink on the electronic control and power is thus spaced from the axial outer face of the rear bearing of the rotary electric machine to provide a mezzanine cooled by air introduced mainly radially between the mezzanine and the axial upper side the rear bearing.

p0207According to an embodiment described in <figref idrefs="f0006">7</figref>, The power module 100b is grounded by a direct electrical contact between the base 109 and the upper face 113a of the heat sink.

p0208An earth cable 529, electrically connected to the dissipator by a securing means 529b such as screwing or welding, is advantageously connected to the negative terminal of the battery of the motor vehicle to form an isolated ground.

p0209As described previously the pads 203 corresponding to the signal connections or from the control or power modules 100b are oriented axially towards the rear of the electrical machine to the electrical connection purposes. Advantageously, these pads 203 reach the plastic cover 511 which contains by overmolding of the metallic power tracks and control. Advantageously, the hood contains any metal traces for carrying out all connections between on the one hand, power modules, and secondly, the power modules 100b with the management unit 2. Thus, this arrangement presents the advantage of not realize wired connections under the hood, providing a significant economic gain. Indeed, all low and high power connections are made in a single pass at the assembly of the cover with traces of metal. Removing these wired connections under the hood used to save space is to reduce For example the axial length of the machine.

p0210The <figref idrefs="f0011">Figures 15 and 16 and 17 and 17a</figref> describe alternative means of electrical connection between the pads 203 and metal traces 600 contained in the cover 511 by overmolding.

p0211As shown in <figref idrefs="f0011">Figure 15</figref> the pad 203 passes through a hole 601, closed or semi-closed, performed in the track 600 to connect. Advantageously the end of the pad 203 out of the other side of the track 600 for fastening by welding means. Reference 602 shows the weld thus formed.

p0212Advantageously, the end 605 of pad 203 is substantially at the same axial height, preferably at a lower height, the upper axial edge of the cover 511 to prevent damage to the solder during handling of the electrical machine. These metal traces are within the openings for 606 formed in the rear cover 511.

p0213The shape of the block 203 is adapted to its positioning tolerance.

p0214The <figref idrefs="f0011">Figure 16</figref> illustrates an alternative embodiment of an electrical connection between a pad 203, preferably power and metallic trace associated with a bolt-nut type screw means. In a manner known per se, a split type Grover washer 608 is interposed between the underside of the bolt and the external face of the metallic track while the stud 103 is clamped between the nut and the underside of the metal trace. In this embodiment, advantageously, a portion 611 of the cap 105 100b module comprising one or three bridge arms, comes into contact with the nut 607 for its blocking in rotation the screwing purposes.

p0215The <figref idrefs="f0011">Figure 17</figref> shows a connection made by welding as described in <figref idrefs="f0011">Figure 15</figref> with a varnish type of protection, glue or silicone to prevent chemical attack type salt spray or humidity. This protection also applies to the nut bolt by fastening means described in<figref idrefs="f0011">Figure 15</figref>.

p0216The <figref idrefs="f0011">Figure 17a</figref> shows a connection made by type of welding laser L in which the pad 203 does not pass through the metallic track. In this case, the trace 203 has a bend 610 adapted to contact stress with the metallic track 600 when the cover 511 is mounted on the back of the electrical machine. This embodiment has the advantage of having a well sealed cover 511.

p0217The <figref idrefs="f0012">Figure 18</figref> illustrates a rear cover according to the invention seen from the rear of the rotating electrical machine. This embodiment corresponds to the case where the heatsink 113 forming mezzanine is electrically insulated from the rear bearing 504. Thus, advantageously, the cap 511 has only one metallic track 600a of high power is able to transit current of about 1000 amperes during starting phases. This metallic track 600a, which preferably includes the connection 650 B + brush holder, and dedicated to the positive terminal B + connected to the electricity network of the motor vehicle can be drawn by occupying all the space it needs without interfering with the other mass 600b necessary when the loft is not insulated and as shown in<figref idrefs="f0013">Figure 19</figref>.

p0218As can be seen the <figref idrefs="f0012">figures 18</figref> and <figref idrefs="f0013">19</figref>It is very easy to connect the drivers 10, 20 and 30, placed centrally close to the rotating shaft, with the management module 2 described above. Thus, according to the invention, it is possible to obtain an electrical machine type alternator-starter having on his back and bearing fixed mechanically, all the power electronics, control and control necessary for its operation. Obviously, as appropriate, electronic functions can be deported in an external housing without departing from the scope of the invention. The architecture of the rear bearing as described above also allows very good cooling of his or her power modules through mezzanine shaped structure cooled by a radial introduction coolant and advantageously axial complement. This cooling is more effective than / power electronic modules are manufactured according to<figref idrefs="f0005 f0006 f0007 f0008">Figures 6 to 12</figref> . The integration of the power electronics of one or more modules, preferably connected via molded-on tracks in the hood provides an extremely easy mounting of power electronics and / or control of the alternator-starter therefore economic. In addition the integration of metallic power tracks in the hood makes it easy to place the cover 630 at any place connector to adapt to the configuration of the motor vehicle.

p0219The <figref idrefs="f0013">Figure 19</figref> is a second cover variant 511 with the metal traces of the invention for forming a sink mezzanine same electrical potential as the rear bearing 504. In this case the power modules are electrically isolated from the sink in this mode embodiment, it is no longer necessary to electrically insulate the struts 527c or 528a forming bonding pads described above. Thus, electrically insulating washers or guns placed at the end of these studs or fastening between the mezzanine and the rear bearing can be removed thereby imparting to the whole rear mezzanine bearing more mechanical rigidity.

p0220In this embodiment, the cover includes, in addition to those described in this <figref idrefs="f0012">Figure 18</figref>The power track 600b dedicated to ground. To reach the connector 630 of the two traces 600a and 600b overlap power in an area 652 of the hood which advantageously has at this point an additional thickness so that the two traces remain overmolding at this location. At this point, the overmoulding of the tracks will be formed to ensure electrical insulation. To make this crossing, at least one of the two tracks will have at least one bent portion.

p0221In this embodiment the connection 651 of the mass of brush holder is also advantageously carried out by the ground trace 600b.

p0222As visible to <figref idrefs="f0012">figures 18</figref> and <figref idrefs="f0013">19</figref>There is also provided a connector 653 for communication with an external control unit, for example via a known protocol type Can, Lan Lin, BSP or simple wire connection.

p0223Advantageously the filter capacitors 653, as seen in <figref idrefs="f0013">Figure 19</figref>Can be connected through the cap 511. The capacitor 653, welded between the traces of Vout power and ground, are an integral part of the cover for example by overmoulding, clipping, bonding. Similarly, one can place capacitor between the metal traces of low power of the hood.

p0224The <figref idrefs="f0015">figures 21</figref> and <figref idrefs="f0016">22</figref> illustrate two embodiments of an alternator rear bearing integrating its electrical control and monitoring on a dissipator bearing 113 constituting a mezzanine according to the invention.

p0225In these two figures, the fastening pads 528a are not electrically insulated so that the bearing sink 113 is not electrically isolated. The masses of the electronic modules 100b are therefore reported at the pads 203a.

p0226The <figref idrefs="f0015">Figure 21</figref> 100b corresponds to the power electronics divided into three modules, each corresponding to a bridge arm and as described in <figref idrefs="f0006">7</figref> whereas <figref idrefs="f0015">Figure 21</figref> corresponds to the arrangement of power electronics incorporating three bridge arms in a single module as described in <figref idrefs="f0009">Figure13</figref>.

p0227In these figures, reference 100a represents the location 100a dedicated to the management module 2 which also has 203c connecting areas.

p0228As seen in <figref idrefs="f0015">Figure 21</figref>The pads 203a and 203b are contiguous power so as to be electrically connected in a single pass, for example at the metal traces of the cover 511 as described above.

p0229680 screws inserted through examples in the housing 111 of the power modules 100b serve to fix these power modules on the heat sink 113.