FR3043439A1 - SPEED TRANSMISSION DEVICE FOR DISPLACING A MOTOR VEHICLE WITH AT LEAST TWO WHEELS AND POWER TRAINING UNIT USING SAID SPEED TRANSMISSION DEVICE. - Google Patents

Abstract

The present invention relates to a transmission device for a motor vehicle, in particular a vehicle with at least two wheels, comprising a driving shaft (12) carrying at least two driving gears (18, 20), a receiving shaft (14) carrying at least two driven gears (34, 36) and a motion-transmitting intermediate shaft (16) carrying stationary gears (52, 54). According to the invention, the device comprises a toothed wheel (56) idly mounted on the intermediate shaft (16) through a unidirectional automatic coupling (58) and cooperating with a drive gear (18).

Description

The present invention relates to a speed transmission device for moving a motor vehicle as well as a powertrain using this speed transmission device.

It aims more particularly but not exclusively a motorized vehicle type two-wheel or three-wheel.

In the French patent application No. 14/54 987 of the applicant, this transmission device comprises a drive shaft carrying two driving gears, a receiving shaft carrying two driven gears and an intermediate motion transmission shaft carrying fixed gears. on this shaft and cooperating with the toothed wheels of the motor shaft and the receiving shaft.

In this transmission device, the driving gear wheels are driven madly by the motor shaft being able to be connected to this shaft by a controlled-controlled coupling for one of the wheels and by a unidirectional automatic coupling for the other wheels. The driven gear wheels are also carried idle by the receiving shaft being able to be connected to this shaft by a controlled-control coupling for one of the wheels and a unidirectional automatic coupling for the other wheels.

During the operation of this transmission, it was found that the unidirectional coupling, typically a free wheel, between the drive shaft and the drive gear could reach a very high speed when the driving gear was in freewheel mode.

This speed could exceed 15,000 rpm, which is outside the limit of operation of the freewheel.

In fact, when the controlled-drive coupling of the motor shaft is engaged, the intermediate shaft is driven and itself drives the toothed wheel provided with a freewheel located on the motor shaft at a speed greater than that of the motor shaft.

Depending on the reduction ratios chosen, and when the speed of the motor shaft is high, the freewheeling speed can then be very high.

Therefore, this high speed can damage the freewheel by preventing it from exerting its function of unidirectional automatic coupling and, in extreme cases, cause a serious malfunction of the transmission or even a stop total of the motion transmission between the motor shaft and the intermediate and receiver shafts.

The present invention proposes to overcome the drawbacks mentioned above by means of a speed transmission device of simple and inexpensive embodiment and which preserves the integrity of the freewheel. For this purpose, the invention relates to a transmission device for a motor vehicle, in particular a vehicle with at least two wheels, comprising a motor shaft carrying at least two driving gears, a receiving shaft carrying at least two driven gears and an intermediate shaft. motion transmission device carrying stationary gear wheels, characterized in that the device comprises a toothed wheel mounted idle on the intermediate shaft through a unidirectional automatic coupling and cooperating with a drive gear. One of the driving gears can be fixedly supported by the motor shaft by cooperating with the toothed wheel mounted idle on the intermediate shaft and the other of the driving gears is carried idle on the motor shaft being associated to a controlled-control coupling for its connection with said shaft. One of the driven gears can be mounted idle on the receiving shaft by being associated with a controlled-control coupling for its connection with said shaft and the other of the driven gears is mounted idle on the receiving shaft through unidirectional automatic coupling. One of the fixed wheels carried by the intermediate shaft can cooperate with one of the driving wheels and one of the driven wheels, and the other of the fixed wheels carried by this shaft can be co-operating with the other driven wheels. .

The device may comprise a closed band on itself connecting the gears.

The closed band on itself may comprise a chain.

The closed band on itself may comprise a belt. The unidirectional automatic coupling may include a freewheel. The controlled-control coupling may include a disk clutch. The invention also relates to a powertrain, especially for a motor vehicle with at least two wheels, comprising an internal combustion engine, a speed transmission device and a drive channel, characterized in that it comprises a speed transmission device. as mentioned above.

The other features and advantages of the invention will now appear on reading the following description, given solely by way of illustration and not limitation, and to which is appended the single figure which is a diagram showing the speed transmission device. according to the invention.

Referring to the single figure, the speed transmission device 10 comprises a driving shaft 12, generally connected to a motor, in particular an internal combustion engine, a receiving shaft 14 which transmits its rotational movement, directly or indirectly, to the wheels of the motor vehicle, and an intermediate shaft 16. The drive shaft 12 carries two toothed wheels 18 and 20 of different diameter and a controlled-control coupling 22 for the wheel 20.

The toothed wheel 18 (called small gear) is fixedly placed on the drive shaft 12 while the other gear 20 (or large gear) is placed on a sleeve 24 surrounding the shaft 12 being free to rotate on this tree but fixed in translation. The controlled-control coupling 22, which may be a friction disc clutch or a synchronizer, makes it possible to connect the wheel 20 in rotation with the drive shaft 12 through the sleeve 24.

For reasons of simplification in the rest of the description, the gears 18 and 20 are called driving gears.

As illustrated in the figure by way of example, the controlled-control coupling 22 is a friction disk clutch. This clutch comprises a reaction plate 26 fixed on the drive shaft 12, a pressure plate 28, free in translation but fixed in rotation with the reaction plate being controlled in displacement towards the reaction plate by any known means, such as levers 30, and a friction disc 32 free in translation on the sleeve 24 but fixed in rotation therewith being placed between the pressure plate and the reaction plate. The receiver shaft 14 which is substantially parallel to the drive shaft 12 carries, as for the drive shaft 12, two driven gears 34 and 36 of different diameter.

The toothed wheel 34 (small driven gear wheel) is placed on a sleeve 38 surrounding the receiving shaft 14 being free to rotate on this shaft but fixed in translation. This toothed wheel 34 has the possibility of being connected in rotation to this receiving shaft by a controlled-control coupling 40, such as a friction disc clutch or a synchronizer.

As for the controlled-control coupling placed on the motor shaft, the controlled-control coupling 40 is here a friction clutch with a reaction plate 42 fixed on the receiving shaft, a pressure plate 44, free in translation but fixed in rotation with the reaction plate, being controlled in displacement towards the reaction plate by any known means, such as levers 46, and a friction disk 48 free in translation on the sleeve 38 but fixed in rotation with the latter this.

The toothed wheel 36 (large driven gear) is placed on the receiving shaft 14 through a unidirectional automatic coupling 50, such as a freewheel.

Of course, it is within the abilities of those skilled in the art to provide known means, such as hydraulic or electric or mechanical actuators, to actuate the levers 30 and 46 according to the desired speed ratio. The rotary motion transmission intermediate shaft 16 is placed substantially parallel to the drive shaft 12 and to the receiver shaft 14. This shaft carries two fixed intermediate gear wheels 52 and 54 of different diameter and an intermediate gear wheel 56 mounted crazy about this tree. This idle wheel is associated with a unidirectional automatic coupling 58, in the form of a freewheel.

It should be noted that the two fixed intermediate gears 52 and 54 may be of the same diameter, which is necessary because the reduction ratio between the idler gear 56 and the small drive wheel 18 is less than that between the intermediate wheel 54 and the driving wheel 20.

Similarly, the two driving gears 18 and 20 may be of the same diameter. In this case, it is important that the reduction ratio between the idle intermediate wheel 56 and the small driving wheel 18 is less than that between the small intermediate wheel 54 and the large driving wheel 20.

As best seen in the figure, the intermediate idler gear 56 cooperates with the fixed small driving gear 18, the large stationary intermediate gear 52 cooperates with the small idler gear 34 and the fixed intermediate gear 54 cooperates with the large mad driving gear 20 and the large crazy driven gear wheel 36.

This makes it possible to carry out three rotational movement transmission paths, a first path A between the small drive gear 18 and the idler intermediate gear wheel 56, another path B between the fixed intermediate gear wheel 52 and the idler driven gear wheel. 34 and finally a last path C between the large driving gear 20, the small intermediate gear 54 and the large driven gear 36.

In the figure, the different wheels of each rotational movement transmission path are interconnected by a band closed on itself, such as a chain or a belt, preferably notched internally and / or externally. By way of example illustrated in the figure, there is provided a chain 60 for connecting the large driving gear 20, the small intermediate gear 54 and the large driven gear 36, a chain 62 for connecting the large intermediate gear 52 and the small driven wheel 34 and a chain 64 for connecting the small driving wheel 18 and the idler intermediate gear 56.

This has the effect of modifying the location of the trees and placing them at a distance from each other according to the available space while ensuring the transmission of the rotational movement between these trees.

Of course and without departing from the scope of the invention, it can be provided to dispense with chain and to cooperate the wheels by mutual meshing.

This transmission device thus configured makes it possible to produce four speed reports.

In one of these speeds, during the rotation of the motor shaft and in the disengaged position of the clutches 22 and 40, the small driving gear 18 is rotated by its connection with the shaft 12. This rotation of the wheel 18 is then transmitted to the intermediate idler gear 56 which, under the effect of the freewheel 58, is connected to the intermediate shaft 16 by rotating it. The rotation of this shaft is transmitted to the fixed intermediate gears 52 and 54.

During this rotation, the large intermediate gear 52 rotates the small driven gear 34 while the small intermediate gear 54 rotates the large driven gear wheel 36. This large driven wheel retransmits this rotation to the receiving shaft 14 thanks to the action of the freewheel 50.

Of course, as the two clutches 22 and 40 are inactive, neither the large driving wheel 20 nor the small driven wheel 34 transmit their rotation to the motor shaft or to the receiving shaft and rotate wildly on these trees.

In another gear ratio, the motor shaft is rotated and the clutch 22 of the drive shaft is in the disengaged position while the clutch 40 of the receiving shaft is in the engaged position. The small driving gear 18 is driven in rotation by its connection with the shaft 12. This rotation of the wheel 18 is then transmitted to the idler intermediate gear 56 which, under the effect of the freewheel 58, is connected to the intermediate shaft 16 by rotating it. The rotation of this shaft is transmitted to the fixed intermediate gears 52 and 54.

The rotation of the large intermediate gearwheel 52 is then transmitted to the small driven gearwheel 34. Through the connection of the sheath 38 carrying this small driven gearwheel with the receiving shaft under the action of the clutch 40, the rotation this small toothed wheel is then transmitted to the receiving shaft 14.

The rotation of the small intermediate wheel 54 causes the large driven gearwheel 36 to rotate. However, in view of the difference in speeds of rotation between the driven wheel 36 and the receiver shaft 14, the latter is uncoupled from the driven wheel by the inaction of the freewheel 50.

The rotation of this small intermediate wheel 54 drives the rotation of the large driving gear 20 but, taking into account the disengaged position of the clutch 20, the large driving wheel 20 connected to the sleeve 24 idly turns on the motor shaft 12.

For another gear ratio, the motor shaft is rotated and the clutch 22 of the drive shaft is in the engaged position while the clutch 40 of the receiving shaft is in the disengaged position. The large driving wheel 20 is then rotated by the drive shaft by the action of the clutch 22 and the small driving wheel 18 is also rotated by its fixed connection with the drive shaft.

The rotation of the driving wheel 20 is communicated to the intermediate shaft 16 by the large intermediate wheel 54 which transmits it to the driven large wheel 36. Given the differential speed of rotation between the large driven wheel and the shaft receiver 14, this wheel is coupled to this shaft by the freewheel by transmitting its rotational movement.

The rotation of the intermediate shaft also causes the rotation of the large fixed intermediate wheel 52, but since the clutch 40 is in the disengaged position, this rotation has no effect on the receiving shaft.

In addition, given the difference in rotational speeds between the idler gear 56 and the intermediate shaft 16, the freewheel is inactive, the intermediate wheel 56 then idly rotates on the intermediate shaft 16.

Considering the two reduction ratios R1 and R2, respectively between the idler 56 and the driving wheel 18, and between the intermediate wheel 54 and the driving wheel 20, with R1 <R2. In the case of the French application No. 14/54 987 of the prior art merited above, the differential speed seen by the freewheel on the motor shaft is R2 / R1, while in the case of the present invention, the speed differential seen by the freewheel 58 on the intermediate shaft 16 is R2 * R1. As a result, the differential speed in the case of the invention is lower than in the case of the aforementioned prior art.

Finally for the last report, the two clutches 22 and 40 are in the engaged position and the motor shaft is rotating. The rotation of this drive shaft 12 is transmitted, by the action of the clutch 22, to the large driving wheel 20 which transmits it to the small fixed intermediate gear wheel 54 of the intermediate shaft 16. The rotation of the latter is transmitted to the small driven wheel 34 via the large fixed intermediate gear 52. The receiving shaft 14 is then rotated by the action of the clutch 40 which connects the small gear wheel led to this shaft.

In this configuration, the rotation of the intermediate shaft 16 also causes, through the intermediary gear 54, the rotation of the large driven gearwheel 36. As already mentioned, given the difference in rotation speeds between the large driven wheel 36 and the receiving shaft 14, and between the intermediate shaft 16 and the idler intermediate gear 56 driven in rotation by the small driving wheel 18, these wheels 36 and 56 are uncoupled respectively from the receiving shaft and the intermediate shaft.

Thus, the transmission device as described above makes it possible to achieve four gear ratios with the advantage of having a freewheel associated with a gear on the intermediate shaft to avoid a high rotational speed of this wheel. free.

As previously mentioned, this speed transmission device 10 can be applied to a powertrain of a motor vehicle, in particular a vehicle with at least two wheels.

This group therefore comprises a propulsion engine, here an internal combustion engine (not shown) connected directly or indirectly to the drive shaft 12, the speed transmission device 10 described above and a drive way of the vehicle connected directly or indirectly to the receiving shaft 14. For example, for a vehicle with two or three wheels, this receiving shaft will be connected to the drive wheel (or the drive wheels) directly through a chain, a belt or a gear train or indirectly by a drive axle carrying the drive wheels.

Claims (10)

1) A transmission device for a motor vehicle, especially a vehicle with at least two wheels, comprising a drive shaft (12) carrying at least two driving gears (18, 20), a receiving shaft (14) carrying at least two gears driven members (34,36) and a motion-transmitting intermediate shaft (16) carrying stationary gear wheels (52,54), characterized in that the device comprises a toothed gear (56) idly mounted on the intermediate shaft (16). ) through a unidirectional automatic coupling (58) and cooperating with a driving gear (18). 2) A transmission device according to claim 1, characterized in that one (18) of the driving gears is fixedly supported by the drive shaft (12) cooperating with the toothed wheel (56) mounted idle on the shaft intermediate (16) and the other (20) of the driving gear wheels is mounted idle on the drive shaft (12) being associated with a controlled-control coupling for its connection with said shaft. 3) A transmission device according to claim 1 or 2, characterized in that one (34) of the driven gear wheels is mounted idle on the receiving shaft (14) being associated with a controlled-control coupling for its connection with said shaft and the other (36) of the driven gear wheels are mounted idle on the receiving shaft (14) through a unidirectional automatic coupling (50). 4) Transmission device according to one of the preceding claims, characterized in that one (54) of the fixed wheels carried by the intermediate shaft cooperates with one (20) of the driving wheels and one (36) driven wheels, and the other (52) fixed wheels carried by this shaft cooperates with the other (34) driven wheels. 5) Transmission device according to one of the preceding claims, characterized in that it comprises a closed band on itself (60, 62, 64) connecting the toothed wheels. 6) A transmission device according to claim 5, characterized in that the band closed on itself (60, 62, 64) comprises a chain. 7) A transmission device according to claim 5, characterized in that the band closed on itself (60, 62, 64) comprises a belt. 8) Transmission device according to one of the preceding claims, characterized in that the unidirectional automatic coupling comprises a free wheel (50, 58). 9) Transmission device according to one of the preceding claims, characterized in that the controlled-control coupling comprises a disk clutch (22, 40). 10) Power train, in particular for a motor vehicle with at least two wheels, comprising an internal combustion engine, a speed transmission device and a driving way, characterized in that it comprises a speed transmission device (10) according to one of the preceding claims.