DE102019115593A1 - The torque transfer device - Google Patents

Abstract

The invention relates to a torque transmission device for a clutch mechanism (1), comprising a friction disc (8) and a hub (29) with an axis X, characterized in that it has a first element (21) which is connected to the friction disc (8) , and comprises a second element (25) connected to the hub (29), the second element (25) comprising ramps which are distributed in the circumferential direction and extend axially and are suitable for counter-ramps of the first element ( 21) cooperate to prevent the first element (21) from pivoting with respect to the second element (25) about the axis X in a first so-called forward direction of rotation, and to pivot the first element (21) with respect to the second element ( 25) in a second so-called reverse direction of rotation.

Description

TERRITORY

The present invention relates to a torque transmitting device, which is particularly intended to equip a vehicle.

CONTEXT

A powertrain of a vehicle makes it possible to transmit a torque of a crankshaft of an internal combustion engine of the vehicle, for example, to the drive wheel or drive wheels of the vehicle.

In normal operation, the torque originating from the crankshaft is transmitted to the wheels via the transmission device, which now rotates in a so-called forward direction of rotation.

In certain operating cases, torque may be transmitted from the wheels to the crankshaft, with the transmission device now rotating in a so-called reverse direction.

Such a case may be present, in particular, when the user releases the accelerator pedal to use the engine brake, or in the case of a gearshift, for example, when the driver switches back at high engine speed.

In order to avoid interference with certain elements of the powertrain and the engine, or to avoid the locking or slipping of the wheels, it may be preferable to limit the torque that can be transmitted in the reverse direction. The torque limit must be sufficient to allow effective engine braking, avoiding wheel lock or premature degradation of the elements. The case corresponding to the locking of the wheels may in particular occur when the vehicle is a motorcycle.

The document FR 2 556 798 in the name of the applicant discloses a clutch mechanism comprising a cover which is fixed to a crankshaft of an internal combustion engine of the vehicle, a reaction plate which is connected to the cover, an axially movable pressure plate which is actuated by the displacement of a diaphragm spring, a friction disc is axially interposed between the pressure plate and the reaction plate. The friction disc is connected to a central hub by means of a torsion damper. The central hub is designed to be non-rotatably coupled to an input shaft of a transmission.

The friction disk is movable between an engaged position in which the friction disk is clamped between the pressure plate and the reaction plate to transmit a torque, and a disengaged position in which the pressure plate releases the friction disk.

To eliminate the aforementioned problem of blocking the wheel or the wheels, it is known to provide a freewheel in the region of the hub of the wheel. Such a solution is relatively complex in use and does not allow the engine brake function to be ensured.

The invention is intended to respond to the abovementioned specifications in a reliable, effective and cost-effective manner, the function of a freewheel being integrated in a clutch mechanism, it being possible in particular to ensure the engine brake function.

SUMMARY OF THE INVENTION

To this end, the invention relates to a torque transmitting device for a clutch mechanism, comprising a friction disc and a hub having an axis X, characterized in that it comprises a first member connected to the friction disc and a second member connected to the hub , wherein the second member includes ramps circumferentially distributed and axially extending, and counter-ramps adapted to cooperate with counter ramps of the first member to pivot the first member relative to the second member to prevent the axis X in a first so-called forward direction of rotation, and to allow the first element to pivot relative to the second element in a second so-called reverse direction, the device comprising resilient means adapted to abut the ramps against the counter-ramps to hold, and friction means that are capable of pivoting the ers element with respect to the second element, when the torque applied in the reverse direction to the hub is less than a limit value.

The friction means may be formed by the ramps and the counter-ramps. In other words, the friction of the ramps on the counter ramps may be sufficient to generate sufficient frictional torque to prevent pivoting of the first member relative to the second member when the applied torque is less than the limit torque in the reverse direction. The limit torque is, for example, between 70 and 100 N.m.

The friction means may also be formed by one or more additional elements.

The friction means make it possible to transmit a torque below the limit value in the reverse direction in order to ensure the engine brake function. Beyond the limit, the first element and the second element play the role of a freewheel, the ramps sliding successively along the associated counter ramps to allow the first and second elements to pivot with respect to each other. The blocking of the drive wheel or the corresponding drive wheels of the vehicle is then prevented.

Conversely, in forward mode, the ramps and the counter-ramps may, for example, come to rest with respect to each other to prevent pivoting of the elements, thus transmitting large torque in the forward direction.

The friction disk can comprise a carrier, with friction linings being mounted axially on both sides of the carrier.

The first element may be integral with the carrier or may be formed by a separate part attached to the carrier by, for example, riveting.

The second element may be integral with the hub or formed by a separate part attached to the hub.

The first element and the second element can be annular.

The position of the ramps and the counter-ramps on the second or first element can be reversed, without the function of the device according to the invention changing. The counter-ramps can thus be arranged on the second element, and the ramps can be arranged on the first element.

The resilient member may be preloaded to exert an axial force independent of the relative angular position of the ramps relative to the counter-ramps.

Each ramp may include a first circumferential end and a second circumferential end axially offset from each other, the second circumferential end being adapted to rest on a peripheral end of the corresponding counter ramp to form a stop which facilitates pivoting of the first member prevents the second element in the forward direction.

The first element may be formed by a metal sheet. The first circumferential ends may be connected to the remainder of the corresponding element, the second circumferential ends being free ends. The ramps may be formed from cut and folded zones to extend axially or from deep drawn zones of the corresponding element.

The axial distance between the first end and the second end, i. the height of the ramp, for example, is between 0.5 and 2 mm, for example between 1.3 and 1.5 mm.

Each counter ramp may be formed by an opening of the corresponding element.

The second element may be formed by a metal sheet.

Each opening can pass axially through the corresponding element.

The first element and / or the second element may comprise a number of ramps and counter ramps between 3 and 100, for example 30, which are regularly distributed around the circumference.

The number of ramps and counter ramps may be selected to provide sufficient reverse thrust torque to permit the passage of sufficient forward torque.

The second element may be axially connected to the hub.

Alternatively, the second member may be axially movable with respect to the hub to avoid the axial displacement of the hub relative to the input shaft of the transmission as the ramps slide against the counter-ramps, thereby increasing the axial displacement of the second member relative to the first member by a value to allow the height of the ramps.

The elastic means can comprise at least one elastic disk which is suitable for exerting an axially aligned force.

The elastic disc is for example an annular and concentric to the axis X plate spring.

The elastic means can be axially between a holding element which is axially connected to the first element or the second element or the second element or the first element.

A first axial end of the elastic means can rest directly or indirectly on the holding element, wherein a second axial end of the elastic means can rest directly or indirectly on the second element or the first element.

In the case of an elastic disk, the radially outer periphery of the disk can rest on the holding element, and the radially inner periphery of the disk can rest directly or indirectly, for example, by means of a friction disk.

A friction disc may be interposed axially between the elastic means and the second member or member.

A friction disc may be axially supported on the outer periphery of the second member by means of an elastic disc, wherein the friction disc is stopped in rotation by an attached support member mounted on the first member concentric with the axis X.

The friction disk can comprise means for rotationally fixed coupling to the holding element, which are formed by fingers which engage in openings in the holding element.

The presence of a friction disk makes it possible to precisely control and maximize the friction torque generated when the first member is pivoted with respect to the second member. The friction disc also prevents damage to the elastic means.

The friction disk may be made of a friction material. The first element and / or the second element may be made of sheet steel or forged steel.

The friction disk can be coupled in a rotationally fixed manner to the first element or the second element.

The holding element may be non-rotatably coupled to the first element or the second element or fastened to it, for example, by means of rivets, wherein the friction plate is non-rotatably coupled to the holding element. The friction disc may include at least one clutch finger engaged in an opening of complementary shape of the retaining element, or vice versa. The coupling finger or the corresponding opening may be located at the radially outer periphery of the friction disk.

The second element may comprise means for centering the first element or vice versa.

The centering means are formed, for example, by centering pins which extend axially from the second element or first element and are suitable for interacting with the radially inner periphery of the first element or the second element.

The second element may be connected to the hub by means of a torsion damper.

Rolling means can be interposed between the ramps and the counter ramps. In this case, the friction torque is only generated, for example, in the area of the friction disk, which makes it possible to better control the value of the friction torque. The rolling means can be formed by balls or by rollers.

The invention also relates to a clutch mechanism comprising a reaction plate intended to be non-rotatably coupled to a crankshaft, a pressure plate actuated by a diaphragm spring, characterized in that it comprises a torque transmission device of the aforesaid type, the friction disc being interposed between the Pressure plate and the reaction plate is interposed, wherein the pressure plate between an engaged position in which the friction disc is clamped between the pressure plate and the reaction plate, and a disengaged position in which the friction disc is released, is movable.

The hub can be non-rotatably connected to a hollow input shaft of a transmission.

The radially inner periphery of the diaphragm spring may be connected to a central actuating shaft, which is at least partially disposed in the hollow input shaft of the transmission. The end of the actuating shaft, which is connected to the diaphragm spring, may extend beyond the hollow shaft.

The diaphragm spring can rest on the pressure plate and on a cover connected to the reaction plate. The contact zone of the diaphragm spring on the cover can be arranged radially outside in relation to the contact zone of the diaphragm spring on the pressure plate.

The clutch mechanism can be of the normally closed type, i.e. can be engaged if no actuation force is exerted on the diaphragm spring.

The invention will be better understood, and further details, features and advantages will be apparent from the study of the following description, which has non-limiting character and refers to the accompanying drawings.

list of figures

• - 1 is an axial sectional view of a clutch mechanism according to the invention;
• - 2 is a perspective view of the first element and the second element from the front;
• - 3 is a perspective view of the first element and the second element from behind;
• - 4 is a perspective view of the first element.

DETAILED DESCRIPTION

1 represents a coupling mechanism 1 according to an embodiment of the invention. The mechanism 1 includes an annular lid 2 , the front end of a crankshaft 3 is attached with an axis X. The lid 2 extends radially. The terms axial and radial are defined in relation to the axis X.

A reaction plate 4 forming an annular flywheel is at the radially outer periphery of the lid 2 for example, by mediating rivets or screws 5 attached. The lid and the reaction plate define an internal volume in which from behind to front a diaphragm spring 6 , a printing plate 7 and a friction disk 8th are mounted.

The diaphragm spring 6 is in the form of an elastic disc whose radially outer periphery on the lid 2 in the area of a support zone 9 rests. The diaphragm spring 6 is also on a zone 10 the printing plate 7 on.

The radially inner periphery of the diaphragm spring 6 is at the rear end of a central operating shaft 11 , which is axially movable, connected. In particular, the radially inner periphery of the diaphragm spring 6 with the actuating shaft 11 under the intermediation of a connecting element 12 and an annular strap 13 connected. Two axial positions of the connecting element 12 and the temple 13 are in 1 shown.

The front end of the actuating shaft 11 is in a plain bearing 14 in a hollow zone 15 the front end of the crankshaft 3 under the mediation of a ring 16 is mounted.

The connecting element 12 includes elastic attachment means 17 at the radially inner periphery, which is the actuating shaft 11 surround and cling to this. The radially outer periphery of the connecting element 12 has hook-shaped zones 18 in which the annular bracket 13 arranged on itself on a backside of the inner periphery of the diaphragm spring 6 rests. The axial displacement of the actuating shaft 11 leads to the axial displacement of the inner periphery of the diaphragm spring 6 us thus to pivot the diaphragm spring 6 around their support zones 9 . 10 ,

In particular the relocation of the actuation shaft 11 forward leads to the shifting of the pressure plate 7 forward into an indented position in which the friction disc 8th between the pressure plate 7 and the reaction plate 4 is clamped. The shift of the actuation shaft 11 to the rear leads to the displacement of the pressure plate 7 back into a disengaged position in which the friction disc 8th is released. The two engaged and disengaged positions of the connector 12 and the bracket 13 are in 1 shown.

The pressure plate 7 is non-rotatable with the reaction plate 4 coupled and is reset to the rear, ie in the disengaged position, by elastic restoring means, not shown, as is known per se.

The friction disk 8th includes an annular support 19 , on both sides of which annular friction linings 20 are fixed, which are intended to be on a front radial surface of the pressure plate 7 or a rear radial surface of the reaction plate 4 to get to the edition.

The radially inner periphery of the carrier 19 is under the mediation of rivets 20 at the radially outer periphery of a first annular element 21 and at the radially outer periphery of a retaining element 22 that is in front of the first element 21 located, fastened.

Every element 21 . 22 is formed by a sheet metal.

The first element 21 comprises a first radial part 21a , which is radially outside, and a second radial part 21b that is radially inside, which are axially offset from each other. The first part 21a is on the carrier 19 the friction disc 8th attached.

How better in 4 can be seen, includes the second part 21b openings 23 extending radially, peripheral edges 24 include and axially through the first element 21 pass. The first element 21 can be formed by a sheet metal.

The first element 21 is a second element 25 assigned. The radially outer periphery of the second element 25 includes radially outer claws 26 ( 2 ), the claws 26 be deformed to extend axially forward. Every claw 26 thus forms an essentially flat ramp 27 ( 2 and 3 ) that is facing forward, with each ramp 27 is inclined with respect to the radial plane. Every ramp 27 includes a first circumferential end 27a that with the rest of the second element 25 is connected, and a second free circumferential end 27b , The axial distance between the first end 27a and the second end 27b , ie the height of the ramp, is for example between 0.5 and 2 mm, for example between 1.3 and 1.7 mm.

The ramps 27 or the claws 26 are regularly distributed around the circumference. The number of ramps 27 is for example between 3 and 100, for example 30 ramps in 2 ,

The ramps are suitable with the openings 24 of the first element 21 to cooperate, the openings forming counter ramps.

The second annular element 25 includes a radial part 28 whose radially outer periphery the claws 26 comprises, and a radially inner cylindrical part 29 which is designed to form a hub. The hub 29 is rotatably coupled to an input shaft of a transmission.

As before, the second element 25 be formed by a sheet.

The radial part 28 includes centering pins 28a which are suitable on the radially inner periphery 21c of the first element 21 to go to the support, to the centering of the first element 21 in relation to the second element 25 to ensure.

A friction ring 30 is at the front radial surface of the outer periphery of the second element 25 under the mediation of an elastic disc 31 held by the type diaphragm spring fitting. The elastic disc 31 also ensures the adjacent support of the second element 25 at the first element 21 , in particular the adjacent stop of the ramps 27 at the counter ramps 27 , The friction ring 30 includes means for non-rotatable coupling 32 on the holding element 22 , which are formed here by fingers, in openings of the holding element 22 are engaged. The radially outer periphery of the elastic disc 31 is on the radially inner periphery of the holding element 22 aural. The radially inner periphery of the elastic disc 31 is on the friction ring 30 aural.

The friction ring disc 30 can be axially related to the holding element 22 shift in reverse during operating phases.

The ramps 27 and the counter ramps 23 are aligned such that the rotation of the first element 21 in relation to the second element 25 around the axis X is prevented in a so-called forward direction, and that beyond a certain torque, the rotation of the first element 21 in relation to the second element 25 in an opposite direction of rotation, called reverse direction, is allowed.

In the case of normal operation, this is from the crankshaft 3 outgoing torque in succession through the lid 2 , the pressure plate 7 , the reaction plate 4 and the friction disk 8th in the engaged position of the diaphragm spring 6 and the printing plate 7 , then the torque is applied to the input shaft of the transmission via the first element 21 and the second element 25 transfer. More specifically, the second ends are in the forward direction 27b the ramps 27 at the corresponding peripheral ends 24 the openings 23 that the counter ramps 23 form, to stop, whereby the rotationally fixed coupling of the first and second elements 21 . 25 is ensured in the forward direction. The maximum torque that can thus travel in the forward direction is, for example, between 150 and 200 Nm. However, the invention is adaptable to any type of transmission.

In the case of a so-called reverse operation, for example, when the driver switches back or suddenly releases the accelerator pedal, the torque from the input shaft to the crankshaft 3 in particular via the first element 21 and the second element 25 run. In such an operating case, the first element 21 in relation to the second element 25 pivot in the reverse direction when the torque transmitted in the reverse direction is greater than a limit value, for example between 70 and 100 Nm. In this case, the ramps 27 on the opposite ramps 23 sliding, such sliding due to the orientation and inclination of the ramps 27 and thanks to the friction ring 30 , which can shift axially, is made possible. With such sliding, the second element shifts 25 axially around the height of the ramps 27 wherein such sliding alternately forward and then backward in the course of passing through the successive Gegenrampen 23 through the ramps 27 he follows.

Such pivoting of the second element 25 in relation to the first element 21 is enabled when the torque transmitted in the reverse direction is greater than the static friction torque that is due to the support of the ramps 27 on the opposite ramps 23 and through the support of the friction ring 30 on the second element 25 is produced.

Such pivoting allows the crankshaft 3 and the input shaft of the transmission over the limit torque in Reverse direction in addition to decouple, in particular to prevent locking of the drive wheel or the drive wheels and a premature deterioration of the transmission elements of the vehicle.

If the torque transmitted in the reverse direction is less than the aforementioned limit torque, while the pivoting of the second element 25 in relation to the first element 21 the elements are not guaranteed 21 . 25 furthermore a rotatable coupling of the crankshaft 3 and the input shaft of the transmission. Such behavior is particularly sought to ensure the engine brake function.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• FR 2556798 [0007]

Claims (12)

A torque transmission device for a clutch mechanism (1) comprising a friction disc (8) and a hub (29) having an axis X, characterized in that it comprises a first member (21) connected to the friction disc (8) and a second member Element (25) connected to the hub (29), the second element (25) comprising ramps (27) and counter-ramps (23) which are circumferentially distributed and extend axially, which are suitable with counter ramps (23) and ramps (27) of the first element (21) cooperate to prevent the pivoting of the first element (21) with respect to the second element (25) about the axis X in a first so-called forward rotational direction, and for permitting the pivoting of the first element (21) relative to the second element (25) in a second so-called reverse direction, the device comprising resilient means (31) adapted to engage the ramps (27) on the counter-ramps (23 ), and Friction means adapted to prevent the pivoting of the first member (21) relative to the second member (25) when the torque applied to the hub in the rearward direction is less than a limit value. Torque transmission device after Claim 1 , characterized in that each ramp (27) comprises a first circumferential end (27a) and a second circumferential end (27b) which are axially offset from one another, the second circumferential end (27b) being suitable, on a circumferential end (24) of the corresponding counter ramp (23) come to rest to form a stop which prevents the first element (21) from pivoting in relation to the second element (25) in the forward direction. Torque transmission device according to Claim 1 , characterized in that each counter-ramp is formed by an opening (23) of the corresponding element (21, 25). Torque transmission device according to one of Claims 1 to 3 , characterized in that the second element (25) is axially connected to the hub (29). Torque transmission device according to the Claims 1 to 4 , characterized in that the elastic means comprise at least one elastic washer (31) capable of exerting an axially oriented force. Torque transmission device after Claim 5 , characterized in that the elastic disc (31) is a disc spring type disc which is annular and concentric to the X axis. Torque transmission device according to one of Claims 1 to 6 characterized in that the elastic means (31) axially between a holding element (22) which is axially connected to the first element (21) or the second element (25) and the second element (25) or the first element (21) are mounted. Torque transmission device according to one of Claims 1 to 7 , characterized in that a friction disc (30) is interposed axially between the elastic means (31) and the second member (25) and the first member (21), respectively. Torque transmission device according to Claim 8 , characterized in that the friction disc (30) is non-rotatably coupled to the first element (21) and the second element (25). Torque transmission device according to one of Claims 1 to 9 , characterized in that the second element (25) comprises centering means (28a) of the first element (21), or vice versa. Torque transmission device according to one of Claims 1 to 10 , characterized in that rolling means, for example balls, between the ramps (27) and the counter-ramps (23) may be interposed. Coupling mechanism (1), comprising a reaction plate (4), which is intended to be non-rotatably coupled to a crankshaft (3), a pressure plate (7), which is actuated by a diaphragm spring (6), characterized in that it has a Torque transmission device according to one of the Claims 1 to 11 The friction plate (8) is interposed between the pressure plate (7) and the reaction plate (4), the pressure plate (7) between an engaged position, in which the friction plate (8) between the pressure plate (7) and the reaction plate (4) is clamped, and a disengaged position in which the friction disc (8) is released, is movable.

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