FR3086712A1 - TRANSMISSION DEVICE FOR HYBRID VEHICLE - Google Patents

Abstract

The invention relates to a torque transmission device (1) comprising: - a torque input element (2), - a torque output element (3), - a clutch (6), coupling selectively and by friction the torque input (2) and torque output (3) elements, - an actuating member (8) of the clutch (6) comprising a piston (15), an actuating stop (16) and a force transmission member (17) for transmitting an actuating force from the piston (15) towards the clutch (6), the force transmission member (17) being supported on a holding (23), - a casing (22) arranged to at least partially envelop the torque input element (2), the torque output element (3), the clutch (6) and the member actuating (8) of the clutch (6), a support bearing (24) is positioned between the holding element (23) of the force transmission member (17) and the casing (22) , the actuation stop (16) and the roller ement of support (24) follow one another axially along the axis B and the actuation stop (16) is composed of rolling elements located between two planes of radial extension and offset axially.

Description

Transmission device for hybrid vehicle

The present invention relates to the field of transmissions for motor vehicles. It relates in particular to a torque transmission device intended to be placed in the traction chain of a motor vehicle, between an internal combustion engine and a gearbox.

It relates more precisely to a torque transmission device for a hybrid type motor vehicle in which a rotating electric machine is arranged in the traction chain.

In the state of the art, hybrid type motor vehicles are known comprising a torque transmission device disposed between an internal combustion engine and a gearbox, a rotary electrical machine as well as a clutch for coupling or uncoupling in rotation a crankshaft of the internal combustion engine to a rotor of the rotating electric machine. Thus, it is possible to shut down the internal combustion engine at each stop of the vehicle and to restart it thanks to the rotating electric machine. The rotating electric machine can also constitute an electric brake or provide additional energy to the internal combustion engine to assist it or prevent it from stalling. When the internal combustion engine is running, the electric machine can act as an alternator. The rotating electric machine can also drive the vehicle independently of the internal combustion engine.

Such a rotary electrical machine can be in line with the torque transmission device, that is to say that the axis of rotation of the rotor of the rotary eclectic machine is coincident with the axis of rotation of the torque transmission device. couple. As a variant, the rotary electric machine can be offset relative to the torque transmission device, that is to say that the axis of rotation of the rotor of the rotary electric machine is offset from the axis of rotation of the rotation device. torque transmission.

In current developments in hybrid vehicles, it is necessary to install the rotary electrical machine on the torque transmission device without, however, this having an impact on the axial and radial compactness of the torque transmission device. One of the conditions for the proper functioning of the torque transmission device is the actuation of the clutch which is conventionally produced by an actuating member comprising a piston moving axially and a rotary stop produced by means of a ball bearing.

This actuator is conventionally called a "CSG" type actuator (Concentric Slave Cylinder). Several problems are linked to these clutch actuation members, namely transmitting an optimal axial actuation force without losses but also ensuring an optimal stroke of the piston without impacting the axial and radial dimension of the torque transmission device.

The invention aims to remedy the aforementioned problems by benefiting from a torque transmission device making it possible to reconcile the requirements of axial and radial compactness while guaranteeing an optimal force transmission between the actuating member and the clutch.

The invention achieves this, according to one of its aspects, thanks to a torque transmission device, in particular for a motor vehicle, comprising:

- a torque input element, capable of being coupled in rotation to a crankshaft of an internal combustion engine,

- a torque output element, able to be coupled in rotation to at least one input shaft of a gearbox and / or to a rotary electric machine, the torque input element being able to pivot by relation to the torque output element around an axis of rotation A,

- a clutch, selectively and frictionally coupling the torque input and torque output elements,

- a clutch actuating member comprising a piston moving along an axis B parallel to the axis of rotation A, an actuating stop and a force transmission member for transmitting an actuating force from the piston towards the clutch, the force transmission member being supported on a holding element,

- A casing arranged to at least partially envelop the torque input element, the torque output element, the clutch and the clutch actuation member, a support bearing is positioned between the holding element for the force transmission member and the casing, the actuation stop and the support bearing follow one another axially along the axis B and the actuation stop is composed of rolling elements situated between two planes radial extension and axially offset.

Thanks to this architecture, the axial compactness of the actuating member which is located opposite the support bearing is improved, which guarantees the actuating member a greater stroke and therefore optimized for the transmission of the actuation force from the piston to the clutch.

The term “axial force rotary stop” is understood to mean a type of bearing supporting only axial forces compared to a simple ball bearing which supports radial and axial forces.

According to one aspect of the invention, the actuating stop is a needle stop, a roller stop or a ball stop. Therefore, the rolling elements are needles, rollers or balls.

The needle, roller or ball stop is provided with a rigid cage to reliably hold and guide the rolling elements. The rigid cage associated with needles, rollers or balls has a high rigidity in a minimum of axial space.

According to another aspect of the invention, the rolling elements are both in contact with the piston which forms the first radial plane and with the force transmission member which forms the second radial plane.

According to a feature of the invention, the surface of the piston which is in contact with the rolling elements and the surface of the force transmission member which is in contact with the rolling elements are hardened. This hardening prevents premature wear due to dynamic contact with the needles, rollers or balls. Curing can be achieved by heat treatment or surface treatment.

According to an alternative embodiment of the invention, a first washer is disposed between the piston and the rolling elements, said first washer forms the first radial plane.

According to another aspect of the invention, a second washer is arranged between the force transmission member and the rolling elements, said second washer forms the second radial plane.

According to a characteristic of the invention, the force transmission member comprises a pusher and a diaphragm.

According to another aspect of the invention, a radial clearance is present between the actuating stop and the pusher and / or the piston. This radial clearance makes it possible to make up for any misalignment defects between the actuating stop and the pusher.

According to an additional characteristic of the invention, the actuation stop is centered on the piston or on the pusher. This characteristic allows the force to be transmitted from the piston to the clutch without loss of efficiency.

According to the invention, the actuating stop and the support bearing are located radially at the same distance from the axis A.

The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given only by way of illustration and not limiting. , with reference to the appended figures.

- Figure 1 is a sectional view of the torque transmission device according to the invention,

- Figure 2 is a partial sectional view of the actuating stop according to a second embodiment.

- Figure 3 is a first sectional view of the clutch actuating member,

FIG. 4 is a second sectional view of the clutch actuation member,

FIG. 5 is a cut perspective view of the cover according to a second embodiment,

FIG. 6 represents an exploded view and a rear view of the cover 25 of FIG. 5.

In relation to FIG. 1, there is a torque transmission device 1 comprising a torque input element 2, coupled in rotation to a crankshaft V of an internal combustion engine (not shown), an output element of torque 3, coupled in rotation to an input shaft of a BV gearbox.

The torque input element 2 is coupled in rotation to the crankshaft V of the internal combustion engine by fixing means 30 in the form of screws. Ten screws are required to attach the torque input element 2 to the crankshaft V of the internal combustion engine.

The torque output element 3 is also coupled to a rotary electrical machine via a first connecting means 102 in the form of a chain.

The torque output element 3 has a ring gear 50 on its outer periphery. The ring gear 50 is in contact with the chain. The torque input element 2 pivots with respect to the torque output element 3 about an axis of rotation A.

An elastic return member 5 acts against the rotation of the torque output element 3 relative to the torque input element 2. The elastic return member 5 is a helical spring.

A clutch 6 selectively and frictionally couples the torque input 2 and torque output elements 3. An intermediate element 7 is arranged between the elastic return member 5 and the clutch 6 to transmit the torque.

An actuating member 8 of the clutch 6 moves along an axis B parallel to the axis of rotation A.

The elastic return member 5 and the clutch 6 succeed one another radially along an axis perpendicular to the axis A.

The actuator 8, the torque input element 2 and the torque output element 3 succeed one another axially along the axis B.

The elastic return member 5 and the clutch 6 are stacked radially, approaching the axis of rotation A.

The elastic return member 5, the clutch 6 and the actuating member 8 succeed one another radially along an axis perpendicular to the axis A.

The elastic return member 5, the clutch 6 and the actuating member 8 are stacked radially, approaching the axis of rotation A.

The torque input element 2 is located between the actuator 8 and the torque output element 3 along the axis B.

The torque input element 2 includes an additional mass of inertia 49. This additional mass of inertia 49 is located near the elastic return member 5.

The torque output element 3 includes a torque output hub 4 removably attached to the torque input element 2 and to the torque output element 3. This removable function allows easy access to the fixing means 30. A holding bearing 31 is disposed between the torque output element 3 and the torque input element 2. The holding bearing 31 allows the radial forces transmitted by the shaft to be taken up input of the gearbox BV and / or the rotating electric machine. The holding bearing 31 is of the double row of balls type. More specifically, the holding bearing 31 is disposed between the torque outlet hub 4 and the torque inlet member 2. The holding bearing 31 is composed of an internal ring in contact with the torque outlet hub 4 and an outer ring in contact with the torque input element 2. The holding bearing 31 is locked axially by two circlips and two shoulders.

The torque output hub 4 may comprise a means for compensating (not shown) for the radial and / or axial and / or angular misalignment between the torque input element 2 and the torque output element 3 so as to that the rotation of the crankshaft around the axis of rotation A is transmitted to the input shaft of the gearbox BV without constraints.

The torque output hub 4 has a grooved orifice for receiving the input shaft of the gearbox BV.

The torque transmission device 1 comprises a casing 22 arranged to at least partially envelop the torque input element 2, the torque output element 3, the elastic return member 5, the clutch 6, l 'intermediate element 7 and the clutch actuating member 8. The housing 22 is wet, that is to say that the aforementioned wrapped components are in an oil mist or partially submerged.

The casing 22 is composed of a front cover or cover 25 located opposite the internal combustion engine, a rear cover or cover 26 located opposite the gearbox BV and a central element 27 connecting the front cover 25 and the rear cover 26. The front cover 25, the central element 27 and the rear cover 26 are fixed to each other by fixing means, for example of the screw or rivet type.

Alternatively, the central element 27 can be integrated at least partially into one of the two covers.

The housing 22 is fixed to the internal combustion engine by means of fixing means, for example of the screw or rivet type. Advantageously, the front cover 25 can be fixed to the internal combustion engine by means of fixing means, for example of the screw or rivet type.

The clutch 6 comprises an input disk carrier integral in rotation with the intermediate element 7, an output disk carrier integral in rotation with the torque output element 3, a multidisc assembly 11 comprising at least one friction disk integral in rotation with one of the input and output disk carriers, at least two plates respectively disposed on either side of the friction disk, integral in rotation with the other of the input and output disk carriers . The friction disc has friction linings on each of its sides. The linings are fixed to the friction discs by gluing, riveting or overmolding.

In a variant not shown, the linings are fixed to the plates.

The clutch 6 can have a engaged position in which said plates pinch the friction disc and its friction linings so as to transmit a torque between the input disc holder and the output disc holder. The clutch 6 may also have a disengaged position in which said plates do not pinch the friction disc and its friction linings so as not to transmit a torque between the input disc holder and the output disc holder.

Each input or output disc holder can synchronize in rotation the set of plates or the set of friction discs. The plates and the discs can cooperate with the entry and exit disc holders along one of their radial peripheries by complementarity of form, the plates and the friction discs can for example be grooved. The plates can be secured in rotation to the input disc holder and the friction discs can be secured to the outlet disc holder.

As a variant, the plates can be integral in rotation with the output disc holder and the friction discs can be secured in rotation with the input disc holder. The trays are radially inside the entrance disc holder with which they are rotatably attached. The friction discs are radially outside the output disc holder with which they are rotatably attached. The clutch has between two and seven friction discs. The clutch preferably has four friction discs. Clutch 6 is of the "normally closed" type. The clutch 6 is of the wet type and is capable of being supplied with fluid by a hydraulic pump (not shown).

The actuating member 8 of the clutch 6 comprises a body 9, an annular piston 15 moving in the body 9 along the axis B which is parallel to the axis of rotation A, an actuating stop 16. A force transmission member 17 is present to transmit an actuating force from the piston 15 to the clutch 6.

The actuator 8 of the clutch 6 is attached to the cover 25 of the casing 22. In other words, the actuator 8 and the cover 25 are two separate parts. The body 9 of the actuator 8 and the cover 25 are made of different materials. The cover 25 is made of steel while the body 9 of the actuating member 8 is made of aluminum or plastic. Thus, the material constituting the cover 25 is harder than the material constituting the body 9 of the actuating member 8. For example, the material constituting the cover 25 has a hardness HB of between 120 and 700. The material constituting the body 9 of the actuating member 8 has a hardness HB of between 10 and 120.

The actuating member 8 of the clutch 6 is provided with a stop (not shown) to limit the output of the piston 15.

The body 9 of the actuator 8 forms an actuation chamber in which the piston 15 is located. The chamber is sealed and filled with oil. The piston 15 includes a seal in order to ensure the tightness of the actuation chamber.

The front cover 25 of the casing 22 has, in section, a general shape substantially in "L" formed by an axial extension 25a parallel to the axis A and a radial extension 25b perpendicular to the axis A. The radial extension 25b of the cover 25 is located at one end of the axial extension 25a of the cover 25.

In the embodiment of FIG. 1, the axial extension 25a of the cover 25 and the radial extension 25b of the cover 25 are in one piece. The axial extension 25a of the cover 25 is substantially in the form of a hollow cylinder while the radial extension 25b of the cover 25 is substantially in the form of a disc.

The body 9 of the actuating member 8 comprises a radial wall 9a substantially parallel to the radial extension 25b of the cover 25, the radial wall 9a and the radial extension 25b are in contact. The body 9 of the actuator 8 is both in contact with the axial extension 25a of the cover 25 and the radial extension 25b of the cover 25.

The radial wall 9a of the body 9 of the actuating member 8 or the radial extension 25b of the cover 25 comprises at least one pipe 10 for the supply of fluid to the actuating member 8 (more precisely the piston) or the cooling and / or the lubrication of the clutch 6.

The piston 15 is supplied with fluid by an external actuator of the electro-hydraulic or electro-hydrostatic type (not shown). The piston 15 of the actuating member 8 of the clutch 6 is controlled in position by force measurement through the current consumption of the electric motor of the external actuator. The piston 15 may have a retracted position in which the piston is close to the front cover 25 and a deployed position in which the piston 15 is remote from the front cover 25. As the clutch 6 is of the normally closed type, the retracted position of the piston 15 corresponds to the clutch 6 closed and the deployed position of the piston 15 corresponds to the clutch 6 open.

The force transmission member 17 comprises a pusher 18 and a diaphragm 19. The actuation stop 16 is composed of rolling elements situated between two planes offset axially. The rolling elements can be needles, rollers or balls.

The actuation stop 16 is supported by a shoulder of the piston 15.

The force transmission member 17 can be supported on the input disc holder by means of a holding element 23. The diaphragm 19 is in contact with the holding element 23.

A support bearing 24 can be positioned between the holding element 23 of the force transmission member 17 and the casing 22 in order to take up the actuating force of said actuating member 8.

The actuating stop 16 and the support bearing 24 follow one another along the axis B. The support bearing 24 is provided with an annular notch. The annular notch is more precisely a shoulder. In a variant not shown, the annular notch can be a groove.

The support bearing 24 is composed of an internal ring in contact with the casing 22 and an external ring in contact with the holding element 23 of the force transmission member 17. The support bearing 24 is axially locked by a circlip in contact with the internal ring. The annular notch in the support bearing is located on the outer ring. The annular notch is more precisely a shoulder formed on the outer ring. This notch or shoulder is produced on one side of the support bearing 24 facing the actuating stop 16.

The retaining element 23 has a projection which cooperates with the annular notch of the support bearing 24. This cooperation in shape between the annular notch and the projection makes it possible to ensure axial mounting of the support bearing 24 without encroaching on the piston stroke 15.

The actuating stop 16 and the support bearing 24 are located radially at the same distance from the axis A. The support bearing 24 is a ball bearing, more precisely a single row ball bearing.

The actuation stop 16 is a needle stop, a roller stop or a ball stop. In the embodiment of FIG. 1, the rolling elements are both in contact with the piston 15 which forms the first radial contact plane and with the force transmission member 17 which forms the second radial contact plane .

The surface of the piston 15 which is in contact with the rolling elements and the surface of the force transmission member 17 which is in contact with the rolling elements are hardened.

A radial clearance is present between the actuating stop 16 and the pusher 18 and / or the piston 15.

The actuation stop 16 is centered on the piston 15 or on the pusher 18.

In Figure 2 is shown a partial sectional view of the actuating stop according to an alternative embodiment. A first washer 12a is disposed between the piston 15 and the rolling elements. The first washer 12a thus forms the first radial plane. A second washer 12b is arranged between the force transmission member 17 and the rolling elements, the second washer 12b forms the second radial plane. This alternative embodiment finds its interest in the case where the surfaces which are in contact with the rolling elements are not hardened.

The body 9 of the actuating member 8 comprises a radial wall 9a substantially parallel to the radial extension 25b of the cover 25, the radial wall 9a and the radial extension 25b are in contact. The body 9 of the actuating member 8 comprises on its outer periphery a spring 13 in contact with the piston 15 and the radial wall 9a. The compression direction of the spring 13 is parallel to the axis A. This spring 13 is used to ensure a minimum preload on the actuating stop 16.

FIG. 3 illustrates a first sectional view of the cover 25 and of the actuating member 8. This figure is focused on the pipe 10 serving for the supply of fluid to the actuating chamber enabling the piston 15 to be moved. The pipe 10 is produced by means of different bores and is mainly located in the cover 25 and more precisely in the radial extension 25b of the cover 25. The pipe 10 opens into the actuation chamber of the piston 15.

A seal is formed at the junction of pipe 10 between the body 9 of the actuator 8 and the cover 25, this seal is achieved by at least one O-ring. The O-ring is placed in a groove in the cover 25.

FIG. 4 illustrates a second sectional view of the cover and of the actuating member 8. This figure is focused on the line 10 serving for cooling and / or lubrication of the clutch 6. The line 10 is produced by l 'intermediary of different holes and is mainly located in the cover 25. The pipe 10 opens out inside the casing 22 at the level of the spring 13 located on the external periphery of the actuating member 8.

In FIGS. 3 and 4, the axial extension 25a of the cover 25 and the radial extension 25b of the cover 25 are in one piece, that is to say that the cover 25 is formed in one piece. The cover 25 is made of steel and the body 9 of the actuating member 8 is made of aluminum or plastic.

FIG. 5 illustrates a second embodiment of the cover 25 in which the axial extension 25a of the cover 25 and the radial extension 25b of the cover 25 are two separate parts. These two parts are then assembled together by welding. The actuating member 8 of the clutch 6 is disposed on the cover 25 once the two extensions 25a and 25b are assembled. The body 9 of the actuating member 8 is both in contact with the axial extension 25a of the cover 25 and the radial extension 25b of the cover 25. The axial extension 25a of the cover 25 is in the form of a hollow cylinder and the radial extension 25b of the cover 25 is disc-shaped. The radial extension 25b of the cover 25 is located at one end of the axial extension 25a of the cover 25.

The body 9 of the actuating member 8 comprises a radial wall 9a substantially parallel to the radial extension 25b of the cover 25, the radial wall 9a and the radial extension 25b are in contact.

6 shows an exploded view and in rear view of the cover 25 of Figure 5. In this figure, it is visible that the radial extension 25b of the cover 25 is divided into a plurality of branches 14 angularly distributed around the axis A. In this embodiment, the radial extension 25b of the cover 25 is divided into six branches 14. The radial wall 9a of the body 9 of the actuating member 8 comprises recesses 14a receiving the branches 14 of the radial extension 25b of the cover 25. This embodiment makes it possible to dispense with the seal between the cover 25 and the body 9 of the actuating member because the pipe 10 for the supply of fluid to the member d actuation 8 or the cooling and / or lubrication of the clutch 6 is located on the radial wall 9a of the body 9 of the actuating member 8.

Although the invention has been described in connection with a particular embodiment, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these these are within the scope of the invention.

The use of the verb "behave", "understand" or "include" and its conjugate forms do not exclude the presence of other than those stated to in a claim.

In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims (10)

1. Torque transmission device (1), in particular for a motor vehicle, comprising: - a torque input element (2), capable of being coupled in rotation to a crankshaft (V) of an internal combustion engine, - a torque output element (3), capable of being coupled in rotation to at least one input shaft of a gearbox (BV) and / or to a rotary electric machine, the input element of torque (2) being able to pivot relative to the torque output element (3) about an axis of rotation A, - a clutch (6), coupling selectively and by friction the torque input elements (2) and torque output elements (3), - an actuating member (8) of the clutch (6) comprising a piston (15) moving along an axis B parallel to the axis of rotation A, an actuating stop (16) and a transmission member force (17) for transmitting an actuating force from the piston (15) towards the clutch (6), the force transmission member (17) being supported on a holding element (23), - a casing (22) arranged to at least partially envelop the torque input element (2), the torque output element (3), the clutch (6) and the actuating member (8 ) of the clutch (6), a support bearing (24) is positioned between the holding element (23) of the force transmission member (17) and the casing (22), characterized in that the actuation stop (16) and the support bearing (24) follow one another axially along the axis B and in that the actuation stop (16) is composed of rolling elements located between two planes of radial extension and axially offset. 2. Torque transmission device (1) according to claim 1, characterized in that the actuating stop (16) is a needle stop, a roller stop or a ball stop, the rolling elements being the needles , rollers or balls. 3. Torque transmission device (1) according to the preceding claim, characterized in that the rolling elements are both in contact with the piston (15) which forms the first radial plane and with the force transmission member. (17) which forms the second radial plane. 4. Torque transmission device (1) according to one of the preceding claims, characterized in that the surface of the piston (15) which is in contact with the rolling elements and the surface of the force transmission member ( 17) which is in contact with the rolling elements are hardened. 5. Torque transmission device (1) according to one of claims 1 to 2, characterized in that a first washer (12a) is disposed between the piston (15) and the rolling elements, said first washer (12a) forms the first radial plane. 6. Torque transmission device (1) according to one of claims 1 to 2 and optionally claim 5, characterized in that a second washer (12b) is disposed between the force transmission member (17) and the rolling elements, said second washer (12b) forms the second radial plane. 7. Torque transmission device (1) according to one of the preceding claims, characterized in that the force transmission member (17) comprises a pusher (18) and a diaphragm (19). 8. Torque transmission device (1) according to the preceding claim, characterized in that a radial clearance is present between the actuating stop (16) and the pusher (18) and / or the piston (15). 9. Torque transmission device (1) according to one of claims 7 to 8, characterized in that the actuation stop (16) is centered on the piston (15) or on the pusher (18). 5 10. Torque transmission device (1) according to one of the preceding claims, characterized in that the actuating stop (16) and the support bearing (24) are located radially at the same distance from the axis A .