Process for shifting the gears of a transmission consisting of several components

DESCRIPTION

The invention relates to a process for changing gears in a gearbox consisting of more than two groups of consecutive gears.

Document DE-A-3 012 661 refers to a gearbox composed of several groups of gears in which the first group of gears corresponds to a transmission without a change of speed or a reduction, the gear change being made hydraulically. A second group of gears concerns a group of gears of synchronized gears and mechanically driven gears, and a final group of gears connected with an output shaft and formed by a gear train with gear shift mechanism of non-synchronized sleeves. Mechanical drive All gear groups allow changes to be made independently of the other gear groups so that a large number of gear shift combinations can be achieved.

This gearbox is improvable, because it does not allow a simple change in the gear train, that is, in the last gear group.

The problem that has been the basis of the invention is to find a system to change gears quickly and easily also in the gear train.

This problem has been solved by the procedure described in the invention, which provides that when making a change in the last group of gears, the direct change unions participating in the change gear group are selected and the formation of joint joints is carried out. change from the last group of gears.

In this way, the gear groups prior to the last group successively reach the rotational speed of the last gear group, which is fixed. This prevents one of the gear groups from having to make a violent adaptation to the speed of rotation between two gear groups. Especially in the changes from forward gear to forward gear, in which there must be a complete stop of the gearbox, this system allows an optimal adaptation to the speed of rotation. Eventually it can also be considered as the last group of gears, whose speed of rotation must reach the other groups of gears, a penultimate or intermediate group of gears, if this is the group that starts from the invariable speed of rotation to which it must be synchronized. A decrease in the time required to make the multiplication changes is obtained, when all the exchange unions are synchronized and the synchronization was not performed only in some. When the gearbox does not have direct exchange unions, it is advantageous to also open these joints to couple as many inertia masses as possible so that they can influence the multiplication change. Optimization is achieved in the process of gear change when the change in multiplication is done automatically and eventually with the support of your pneumatic, electric or hydraulics.

In the drawing, a gearbox with a gearbox is schematically represented, by means of which the procedure described in detail below can be carried out according to the invention. The gearbox illustrated in the drawing is subdivided into five groups I to V, whose designation is as follows: I clutch, II group of reduction gears with changeable capacity under load, III group of four-speed gearboxes, IV gear shift gear, and V shift device.

The clutch I consists of two halves 10, one of which was attached to the motor 12 and the other was connected to the input shaft 14 of the reduction gear group II. The clutch I can be of both conventional type by multiple friction discs of mechaonic inlet and outlet coupling and of hydraulic type of multiple discs. It is actuated respectively when a multiplication change is made in the gear group III or in the gear train IV.

The reduction gear group II shows a housing 16, which can be rigidly attached to a frame or the like by means of the multi-disc brake 18, thus having the possibility of turning freely, an output shaft 20, a double sprocket 22 located on the housing 16 with the possibility of rotation with respect to said housing, and a multi-disc clutch 24. An output gearwheel 26 is logically attached to the output shaft 20, engaging at one end with the double gearwheel 22, and logically joins the output shaft 20 to the housing 16 through the disk clutch 24 when the element is operated corresponding control. The double gearwheel 22 meshes at the other end with an input gearwheel 28 loosely connected to the input shaft 14 and having a smaller diameter than the output gearwheel 26. The disc brake 18 and the disc clutch 24 are connected to the change device V via the control lines 30 and 32, respectively, so that the reduction gear group II can be transformed into a direct transmission or a transmission reductive

In direct transmission, the output shaft 20 and the output gearwheel 26 remain rigidly connected to the housing 16 through the disc clutch 24, so that the double gearwheel 22 is also fixed when deemed necessary and acts only as a fixed connecting element between the input sprocket 28 and the output sprocket 26, whereby no reduction in the speed of rotation of the input shaft 14 was made. In this situation the disc brake 18 is kept open.

In the reduction transmission, the disc brake 18 is kept closed, which prevents the rotation of the housing 16 while the disc clutch 24 remains open, and there may be relative movement between the output sprocket 26 and the housing 16. In this case In this case, the rotation speed of the input shaft 14 is reduced by passing through the double sprocket 22. The coupling of the disc clutch 24 and the disc brake 18

two it is performed by pressure, being controlled by the change device V through the control lines 30 and 32.

The gear change group III incorporates in the present embodiment four gear wheels 34, 36, 38 and 40 of different diameters, which can rotate with respect to the output shaft 20 of the reduction gear group II, being able to prevent rotation with with respect to the axis 20 by means of the synchronization device 42 for the sprockets 34 and 36 and by means of the synchronization device 44 for the sprockets 38 and 40. The synchronization devices 42 and 44 are operated from the switching device V through the control connections 46 and 48, respectively. Four sprockets 50, 52, 54 and 56, with no relative movement between them, joined by a hollow shaft 58, engage with the four sprockets 34, 36, 38 and 40. Said set of sprockets 50, 52, 54 and 56 can rotate with respect to the output shaft 60 which constitutes the driving of the wheels of a vehicle that are not represented in the drawing. Depending on the sprocket 34, 36, 38 or 40 that is connected to the output shaft 20 by means of synchronization devices 42 or 44, a significant or small reduction in the number of revolutions in the output shaft 60 was made.

The gear train IV also consists of a double sprocket 62, which remains fixed with respect to the sprocket 34 on the output shaft 20 of the reduction gear group II, always engaging with the slow sprocket 64 and with the reverse gearwheel 66. The gearwheel 66 serves solely to reverse the direction of rotation and is permanently engaged with the reverse gear sprocket 68. The slow sprocket 64 and the rear gear sprocket 68 can rotate freely on the output shaft 60 and can also be rigidly attached to the output shaft 60 by means of the synchronization device 70. On the other hand, the hollow shaft 58 can be rigidly joined to the output shaft 60 via the synchronization device 72. The synchronization devices 70 and 72 are operated through the control lines 74 and 76, respectively, from the change device V.

The shifting device V can be manufactured without any limitation, only taking into account that it is advisable to incorporate a shifter 78 that initiates the multiplication ratio change operations then described in the shifting gear group III or in the gear train gears IV, through an electric circuit integrated in the changeover device V and which does not appear in the drawing.

The function of the reduction gear group, the gear shift group and the gear train II, III and IV, respectively, and their detailed arrangement can be obtained from DE-OS 3 012 661, to which reference is expressly made herein.

Essentially its function is as follows. The reduction gear group II optionally made a controlled variation of the rotation speed of the input shaft 14 of approximately 20%, which is maintained up to the axis of

115 4 output 60. In the gear train IV, an inversion or reduction of all the multiplications made in the gear group III, and in the same gear group was made

III there is again intermediate multiplications in the multiplication range of the gear train IV. The change of multiplication in the gear change group III and in the gear reduction group II was carried out in the same way as indicated in DE-OS 3 012 661 and for this reason it is not indicated again in the present document

The shifting device V was arranged in such a way that when a multiplication change is made in the gear train IV the disengagement of all the synchronization devices 42, 44 of the shifting gear group III first occurs and, if possible, also of the synchronization devices of the gear group

IV with the assigned sprockets 34-40 or with the hollow axle 58, the slow sprocket 64 and the rear gear sprocket 68. Eventually the disc brake 18 and the disc clutch 24 can also be released so that Direct transmission occurs in the reduction gear group II. The movement is then transmitted by the hollow shaft 58, the slow gear 64 or the rear gear wheel 68 to the output shaft 60 through the corresponding synchronization devices 70 or 72. Once said transmission was made, the transmission was carried out. a multiplication in the gear shift group III by coupling one of the synchronization devices 42, 44. The disc brake 18 or the disc clutch 24 of the reduction gear group II is then coupled if previously released. Finally, the transmission of the torque between the engine 12 and the wheels (not indicated in the drawing) is made by clutch re-coupling

I.

An example of a multiplication change of this type in the gear train IV starts from the fact that the reduction unit II provides a direct transmission, the progressive change unit III offers the minimum multiplication and the gear train IV is in the gear group slow, that is, the slowest group. This means that the disc clutch 24 was coupled, that the sprocket 40 was coupled through the synchronization device 44 with the output shaft 20 and by the sprocket 56 with the hollow shaft 58, and that the hollow shaft 58 was connected to the output shaft 60 through the gearwheel 50, the gearwheel 34, the double gearwheel 62, the idle wheel 64 and the synchronization device 70. This situation corresponds to a first direct idle. In this situation, a first direct backward march should now be put in.

To this end, the clutch I. is released first. Next, the shifter 78 must be placed in the position corresponding to the first direct reverse gear so that the shifting device V can carry out the necessary shifting process. By this device, it is first made that synchronization devices 44 and 70 cease to be engaged.

025 115 swims with the gearwheel 40 and the idle wheel 64. The disc clutch 24 of the reduction gear group II can also be released if desired. Once all these force transmissions have been interrupted, the vehicle slowly slows down and the output shaft 60 begins to stop. The output shaft 60 cannot be separated from the connection with the wheels of the vehicle, so its turning speed must be that corresponding to the position of the gear train elements IV, the gear shift group III and the reduction gear group II. The rear gear wheel 68 is then connected to the output shaft 60 through the synchronization device 70. Finally, the synchronization device 44 connects the output shaft 20 with the gearwheel 40. The disc clutch 24 must be disengaged so that it can be re-coupled. The transmission of clutch power I, which has to be coupled to the wheels, was then carried out through the following path, passing through clutch I: input sprocket 28, housing 16, output shaft 20, sprocket 40, gearwheel 56, hollow shaft 58, gearwheel 50, gearwheel 34, double gearwheel 62, reverse wheel 66, reverse gear wheel 68 and output shaft 60. During the clutch engagement I there is an equalization of the speed of rotation of the engine 12 so that the movement towards the rear of the vehicle can begin.

The advantage of this gear change procedure is that when uncoupling masses of inertia in motion, small turning torques are produced in synchronization devices 42, 44, 70 and 72, especially in those of the gear train IV, so that the synchronization devices can be of small size, and taking up little space in the gearbox allow a change of multiplication more easily.

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