Contiuously-variable multi-speed transmission

The invention relates to a transmission arrangement, in particular for a motor vehicle, with a Change-speed gear and at least two transmission input shafts, which different Gear stages are associated with, and a method for controlling such Gear assembly.

From DE-OS 18 04 533 it is known, for example, on a side shaft of the gear change transmission a propulsion unit, such as a hydraulic motor, providing that active for speed synchronization of sub-shaft and engageable gear parts makes.

From DE-C3-19 41 445 it is known an electric motor and a friction clutch at a provide countershaft. The engine accelerates the countershaft and the friction clutch slows the countershaft so that for the smooth engagement of a gear Synchronism is generated in the transmission.

Both devices have the disadvantage that intermittently during gear changes of tension over time runs.

The present invention is therefore the object of a transmission arrangement and to provide a method of the above type are available, with a variable-speed transmission can be formed to an automatic transmission with high shift comfort and operable.

This object is inventively achieved by a gear arrangement with the in claim 1 dissolved marked characteristics, while the method claimed in claim 7 becomes.

For this purpose the invention provides that the at least two transmission input shafts are connected to an auxiliary drive. This has the advantage that the additional drive the Task of synchronizing accepts, a generator, a starter, means for replaced allowing an engine braking operation and a starting clutch and a sliding, ie, a continuous adjustment of the gear ratio or the torque transmission allows.

To increase the flexibility of the transmission system with respect to different changing Operating conditions is advantageously a drive motor via sliding sleeve n a clutch with one or two transmission input shafts selectively connectable.

In addition, torque peaks are achievable by the at least two transmission input shafts, are connected via a planetary gear with the additional drive.

Depending on the application and operating requirements, the additional drive an electric or a Hydraulic motor. The electric motor can in braking phases advantageously as a generator and the hydraulic motor are respectively used as the hydraulic pump, so that kinetic Energy is not simply destroyed to heat, but for other functions in the system is available.

A continuous switching operation is achieved additionally by the fact that a transmission input shaft the straight and the other transmission input shaft, the odd gear stages assigned.

A automated operation is achieved in that, and to the transmission input shafts a countershaft means for determining a rotational speed or speed difference disposed are, which provide corresponding signals to a control device.

In an inventive method of the aforementioned type are inventively following Steps provided:<sl><li>(A) increasing the torque of the auxiliary drive in a motor mode, to an Torque on the second transmission input shaft on the drive side to zero or negative will and a drive-side connection of the second transmission input shaft freewheeling conditionally opens,</li><li>(B) applying the second transmission input shaft with a torque by means of the Auxiliary drive, wherein the rotational speed of the second transmission input shaft as long Synchronous operation is changed to a shift sleeve of the second gear stage prepared becomes,</li><li>(C) inserting the second gear stage,</li><li>(D) driving and braking means of the auxiliary drive, up to a shift sleeve of first gear, the torque to zero or negative and this shift sleeve freewheeling conditionally opens,</li><li>(E) Increase or decrease the torque of the additional drive, until a value is reached is in which a continuous traction profile is possible,</li><li>(F) producing a drive-side connection of the second transmission input shaft, when a rotational speed difference at this connection a predetermined threshold below.</li></sl>

This has the advantage that a continuous adjustment of the gear ratio or the Torque transmission is possible.

The lowering of the torque of the additional drive, to the auxiliary drive a generator to acts charging a battery, allows advantageously, the auxiliary drive in addition instead to operate a generator, so that a further component is saved.

Continuous adjustment of the translation is achieved in that between the Steps (c) and (d) is controlled the auxiliary drive in such a way that a driving torque results which lies between the values ​​of the gear steps involved.

Further features, advantages and advantageous embodiments of the invention will be made the dependent claims and from the following description of the invention to Reference to the accompanying drawings. These show in:<dl tsize="7" compact="compact"><dt>Fig. 1</dt><dd>a schematic representation of a preferred embodiment of the invention Gear assembly and </dd><dt>FIG. 2</dt><dd>an equivalent circuit diagram of the transmission system of FIG. 1</dd></dl>

Referring to Figures 1 and 2 will be described the structure and function of a Gear assembly according to the invention using the example of a preferred embodiment illustrated, described.

A gear change transmission 10 has two input shafts 12 and 14 and several Gears 13, 16, 18, 20 and 22 with respective shift sleeves 15, 17, 19, 21 and 23. On the drive side, the transmission input shafts 12 and 14 via a clutch 32 with Shift sleeves 28 and 30 are selectively connected to a drive motor 26th About a planetary gear 34 are the transmission input shafts 12 and 14 with an auxiliary drive 24, as For example, an electric motor or a hydraulic motor, connected.

The transmission input shaft is thus in part 2 shafts 12 and 14 for odd and even Gears 16, 18, 20 and 22 are divided. each one is over the clutch 32 of the Shafts connected to the motor 26th About the planetary gear 34 are both part shafts 12 and 14 with the auxiliary drive 24 in conjunction. An auxiliary drive 24 in the form of a Electric machine, which is preferably suitable for a 2- or 4-quadrant operation, takes on the central synchronization, replacing a generator, a starter and a starting clutch torque increase. The operation of the transmission 10 is carried out as at a known power shift.

The two partial waves 12 and 14 with the respectively associated gear stages 16, 18, 20 and 22 are on the separate drive 24, 34 connected to each other. By means of the so einleitbaren Torque tensile forces and torques can be displayed whose values ​​between the values the gear steps involved are. If the auxiliary drive 24 via the planetary gear 34 connected to the two shafts 12 and 14, as well as torque increases are achieved, for example for starting or for short-term increase in performance ( "kickdown").

This leads to a sliding gear changes with continuous tension over time. Also in Traction are traction uninterruptible Vollastrückschaltungen possible. through motor or regenerative inclusion of the additional drive 24 is a continuous adjustment the translation, ie a driving operation between the gear ratios possible. with correspondingly higher performance of the additional drive, such as an electric motor, are further Hybrid drives displayed.

Below is the sequence of functions using the example of a circuit of the third gear 20 in the fourth gear 22 are exemplified. It is understood that certain Processes, as speed increases and -verringerungen just reversed if a higher gear to a lower gear to be shifted.

In the initial situation, a vehicle in third gear 20. The shift sleeve 28 between a flywheel 46 and the first transmission input shaft 12 which with a first, third and fifth gear 16, 20, 13 is closed.

with At the same time closed shift sleeve 30 of the second transmission input shaft 14 second and fourth gear 18, 22 acts, the electric motor 24 as a generator to charge the battery.

the switching operation to insert a new gear is introduced Next:

After reaching a switching condition, for example, engine speed greater than 1500 r / min, the Moment 48 of the electric motor for a predetermined ramp rising in the motor Operating controlled until the moment on the shift sleeve 30 is negative and the Shift sleeve 30 free-conditioned opens.

Thereafter, the speed of the second shaft 14 in synchronism with a small moment about 48 the shift sleeve 23 of the fourth gear 22 regulated. When will achieve synchronous running the fourth gear 22 inserted.

Now, the engine speed is adjusted and solved the old gear:

After inserting the fourth gear 22, the torque 48 over a predetermined ramp increasing control in the regenerative mode, to the moment on the sliding sleeve 21 of the third gear 20 is zero or is negative, the shift sleeve 21 opens freewheeling conditionally. Then, the moment is 48 increases with a steep ramp continues until such Kupplungsreibmoment is reached, which ensures the continuity of the tension curve.

It then follows the completion of the shift:

If the speed difference is less than about of the sliding sleeve 30 of the second shaft 14 as a predetermined Threshold value, the shift sleeve 30 of the second shaft 14 is inserted. subsequently is lowered, the motor torque of the electric motor 48. Possibly done the lowering into the generator range for charging a battery.

With an existing engine management, in addition during the speed adjusting the lowered engine torque 38, so that the drive torque 42, off the Transition moments 40 of the third and fourth gear 20 and 22 is composed, on a Value is set corresponding to the torque requested from an accelerator pedal. The drive torque however, it should before and after the switching process preferably between the value lie.

Depending on capacity and state of charge of the battery, the electric motor can be used to design the traction course be used. For example, for braking or for briefly increase acceleration by extreme deflection of the accelerator pedal (Kickdown).

LIST OF REFERENCE NUMBERS

<dl tsize="3" compact="compact"><dt>10</dt><dd>Change-speed gear</dd><dt>12</dt><dd>first transmission input shaft</dd><dt>13</dt><dd>fifth gear</dd><dt>14</dt><dd>second transmission input shaft</dd><dt>15</dt><dd>Shift sleeve of fifth gear</dd><dt>16</dt><dd>first grade</dd><dt>17</dt><dd>Shift sleeve of the first gear stage</dd><dt>18</dt><dd>second gear</dd><dt>19</dt><dd>Shift sleeve of the second gear stage</dd><dt>20</dt><dd>third grade</dd><dt>21</dt><dd>Shift sleeve of the third grade</dd><dt>22</dt><dd>fourth grade</dd><dt>23</dt><dd>Shift sleeve of the fourth grade</dd><dt>24</dt><dd>accessory drive</dd><dt>26</dt><dd>drive motor</dd><dt>28</dt><dd>Shift sleeve of the first gear input shaft</dd><dt>30</dt><dd>Shift sleeve of the second gear input shaft</dd><dt>32</dt><dd>clutch</dd><dt>34</dt><dd>Planetary gear train</dd><dt>36</dt><dd>Countershaft</dd><dt>38</dt><dd>engine torque</dd><dt>40</dt><dd>Torque via respective gear</dd><dt>42</dt><dd>driving torque</dd><dt>44</dt><dd>drive axle</dd><dt>46</dt><dd>flywheel</dd><dt>48</dt><dd>Torque of the additional drive</dd></dl>