FR3075907A1 - TORQUE TRANSMISSION DEVICE - Google Patents

Abstract

Torque transmission device (2), adapted to be arranged between the crankshaft (4) and the gearbox (7) of a powertrain (1) of the vehicle, the device (2) comprising: - a first path of torque through a first damper (10) having a first stiffness which is linear, - a second torque path through a component (20) implementing a fluidic coupling, - a second damper (11) having a second stiffness which is non-linear, this second damper (11) interacting with the component (20) so as to generate in the second torque path a compensation torque of torsion oscillations related to acyclisms, and - an actuator (12) acting especially or part of the operating range of the device on the second damper (11) so as to maintain or reduce the second damper in a plurality of positions in which the second stiffness is negative, - an additional component (21) m an additional fluid coupling, the component (20) and the additional component (21) being in selective fluid communication, and - a selective shutter (50) system for the fluid communication between the component (20) and the additional component (21).

Description

Ιλ ^ Ρ.ΟίίΜU, weakened transmission

The present invention relates to a torque transmission device, capable of being disposed between the crankshaft and the gearbox of a vehicle powertrain.

To damp the torsional oscillations generated by the acyclisms of the thermal engine of this powertrain, it is known to use one or more stages of springs whose displacement, when a torsional oscillation propagates, allows the damping of this oscillation of torsion. The damping of torsional oscillations is all the more effective as the springs have a low stiffness. However, the production of low stiffness springs assumes that these springs are of a large size, which is incompatible with the reduced space available to accommodate them and adds inertia to the powertrain. In addition, low stiffness springs correspond to greater deflections to transmit the average torque provided by the heat engine, such deflections not being compatible with the space available to accommodate these springs.

We know from application FR 3 020 426, from the Applicant, a torque transmission device comprising: - a first spring damper, having a first stiffness which is linear, - a second spring damper, having a second non-stiffness linear and negative over a given value range, and - an actuator arranged to maintain the second spring damper in a position in which the second stiffness is negative, in a part of the operating range of the engine of the powertrain.

Such a device makes it possible to ensure that the overall stiffness formed by the paralleling of the first spring damper and the second spring damper is low, or even zero, in said part of the operating range of the heat engine.

There is a need to further improve the damping of torsional oscillations. The object of the invention is, according to one of its aspects, to meet this need and it achieves this by means of a torque transmission device, capable of being disposed between the crankshaft and the gearbox d '' a vehicle powertrain, the device comprising: - a first torque path through a first damper having a first stiffness which is linear, in particular positive - a second torque path through a component implementing a fluid coupling, this component comprising an inlet part and an outlet part, movable relative to one another in fluid, in particular liquid such as oil, the inlet part being able to be rigidly connected to the crankshaft , - a second damper having a second stiffness which is non-linear, this second damper interacting with the component so as to generate in the second torque path an oscillation compensation torque torsional relationships linked to acyclisms, and - an actuator acting on all or part of the operating range of the device on the second shock absorber so as to maintain or bring the second shock absorber back into a plurality of positions in which the second stiffness is negative.

According to the invention, the actuator is not disposed in the second torque path. The first damper and the component implementing the fluid coupling are for example arranged in the same housing, for example sealed from the outside and filled with fluid, for example oil. The actuator may or may not also be disposed in this housing. The second damper, and if necessary the actuator, can be disposed outside of this housing. The advantage of positioning the actuator outside of such a housing is that its control is not made more complex by the fluid since the latter is not in contact with the actuator. Another advantage can come from the fact that the offset position of the second damper and of the actuator avoids having to come and insert this second damper and the actuator in the axial space between the crankshaft and the gearbox, axial space which is already crowded. In addition, when the second shock absorber and the actuator thus offset do not rotate with the first shock absorber, the inertia of the torque transmission device is reduced. The actuator and the second damper are for example arranged in a housing which is remote from the housing in which the first damper and, where appropriate, the component, are arranged. As a variant, the first damper and the actuator are arranged in the same housing, this housing being at a distance from the housing in which the second damper is arranged.

The second damper can deform from an unstable equilibrium position to compensate for part of the torque generated by the torsional oscillations linked to the acyclisms of the heat engine, the other part of this torque generated by these torsional oscillations being for example compensated by the deformation of the first shock absorber

The deformation of the second damper from an unstable equilibrium position can: - either cause this second damper to occupy the plurality of positions in which the second stiffness is negative, - or bring it into other positions for which the second stiffness n is more negative and for which this second damper can no longer oscillate around its unstable equilibrium position. In the latter case, the actuator can return the second damper to the positions for which the second stiffness is negative, and for which it can oscillate around its unstable equilibrium position. This unstable equilibrium position is that occupied by this second shock absorber when no torsional oscillation linked to an acyclism is propagated in the powertrain.

When such a torsional oscillation propagates in the transmission device, the torque for compensating the torsional oscillations linked to acyclisms generated by the deformation of the first damper can be of opposite sign to the torque compensating for the torsional oscillations linked to acyclisms generated by the deformation of the second shock absorber. The action of the actuator on the second damper can allow the stiffness of this second damper to remain negative over the entire operating range of the device, this operating range corresponding to any value of average torque supplied by the heat engine between the minimum mean engine torque and maximum mean engine torque. In other words, the overall stiffness formed by putting the first damper in parallel with the second damper is low, or even zero, throughout the operating range of the heat engine. This overall stiffness is for example between 1 and 4 Nm / °, being in particular between 1.5 and 3 Nm / °. This overall stiffness then corresponds to the sum of the first stiffness and the second stiffness.

The first path conveys, for example, the average torque supplied by the heat engine and the torque for compensating for torsional oscillations linked to acyclic movements provided by the deformation of the first damper, while the second path routes the compensation torque for torsional oscillations linked to acyclisms provided by the deformation of the second shock absorber.

The first damper may include coil springs or straight springs.

The first damper may comprise a single stage of springs or several, in particular two, stages of springs in series. As a variant, the first damper may comprise elastic blades, each of these blades cooperating respectively with a roller.

Within the meaning of the present application, the first damper can be movable in rotation about an axis, hereinafter called "axis of the device", and: - "axially" means "parallel to the tax of the device", - "radially" means "in a plane perpendicular to the axis of the device and along a straight line intersecting the axis of the device", - "circumferential" means "around the Tax of the device", - "upstream" and "downstream" refer to torque path from the crankshaft to the gearbox, - "input" and "output" refer to the torque path from the crankshaft to the gearbox. One of the input part and the output part of the component can be a body and the other of the input part and the output part of the component can define a chamber inside which is mobile the body, especially in rotation. The body is for example the component input part while the component output part defines the chamber. The component can be a rotary valve.

The device may comprise an additional component implementing an additional fluid coupling, this additional component comprising an additional inlet part and an additional outlet part, movable relative to each other in fluid, for example liquid such as oil, the component and the additional component being in fluid communication.

The relative displacement of the additional input part with respect to the additional output part can cause by fluid means a displacement of the second damper relative to its unstable equilibrium position.

The fluid present in the component can be the same as that present in the additional component and circulate successively in one then in the other. This is for example oil.

When the engine of the powertrain generates an acyclism for a given average torque, a torsional oscillation propagates in the powertrain so that a deformation of the first shock absorber occurs. This deformation leads to a relative movement of the input part and the output part of the component, this movement being an oscillation around an equilibrium position. Due to the fluid communication between the component and the additional component, this oscillation movement is transmitted to the additional component. The second damper, via the torque it exerts in the second path of the device, makes it possible to dampen this torsional oscillation. The system formed by the component, the additional component and the second shock absorber can thus be considered as a system oscillating around an equilibrium position.

The second shock absorber can comprise an elastic deformation system, this system being: - on the one hand fixed on one of the additional input part and the additional output part, and - on the other hand on a frame.

The frame may be the engine powertrain housing or the gearbox housing.

The elastic deformation system can be prestressed in the unstable equilibrium position of the second shock absorber. The deformation of this system, from the prestressed position, makes it possible to give this second shock absorber a second negative stiffness in the plurality of positions of this second shock absorber.

In an exemplary implementation of the invention, the additional outlet part is a jack rod and the additional inlet part defines a chamber filled with fluid, for example liquid such as oil, at the inside which the cylinder rod moves. In this example of implementation, the jack rod can move along an axis, for example parallel to the axis of rotation of the device, and the elastic deformation system can comprise springs, each spring extending orthogonally to this axis, in the unstable equilibrium position of the second> shock absorber.

Four springs are for example provided. One of these springs extends between a first end of the jack rod and a first wall secured to the frame, another of these springs extends between the first end of the jack rod and a second wall secured to the frame , opposite the first wall, another of these springs extends between a second end of the cylinder rod, opposite the first end, and the first wall, and another of these springs extends between the second end of the cylinder rod and the second wall. The actuator can be configured to selectively inject pressurized fluid into the additional component.

The relative displacement of the additional input part with respect to the additional output part can be caused by the relative displacement of the input part with respect to the output part, transmitted by the fluid communication between the component and the component additional, and the injection of pressurized fluid by the actuator into the additional component can be done to oppose all or part of this relative movement of the additional input part with respect to the additional output part. This injection of fluid can allow i to bring the second damper back into the positions in which it has the second negative stiffness or to maintain this second damper in these positions.

In addition to bringing or maintaining the second damper in the plurality of positions in which the second stiffness is negative, this injection of fluid can also preserve the integrity of the component and / or of the additional component. In the case where the component is a rotary valve and where the additional component is a linear actuator, the injection of fluid can make it possible to avoid abutment within the actuator, despite the variations in average torque.

The jack can carry a piston delimiting two compartments within the chamber and the actuator can inject pressurized fluid into one and / or the other of these compartments. The injection of pressurized fluid into a first compartment of the additional component for example following a reduction in the volume of this compartment due to a relative displacement of the additional inlet part and the additional outlet part in a first direction, consecutive to the relative movement of the input part and the output part due to a variation of the average torque supplied by the motor of a first sign. The injection of pressurized fluid into a second compartment of the additional component, for example following a reduction in the volume of this compartment due to a relative displacement of the additional inlet part and the additional outlet part in a second sense, consecutive to the relative displacement of the input part and the output part because of a variation in the average torque of a second sign. The actuator comprises for example a proportional distributor with several positions, one of these positions corresponding to the non-injection of pressurized fluid into the additional component while another position corresponds to the injection of fluid. When two compartments are defined in the additional component, the distributor can be in three positions: - a first position corresponding to the non-injection of pressurized fluid into the additional component, - a second position corresponding to the injection of pressurized fluid in the first compartment of the additional component, and - a third position corresponding to the injection of pressurized fluid into the second compartment of the additional component.

In all of the above, the device may include a pendulum damping system. The pendulum damping system comprising a support is preferably rigidly coupled to the outlet of the first damper. The pendulum damping system comprises a plurality of pendulum bodies movable relative to the support. The movement of each pendular body relative to the support is for example guided by at least one rolling member, or even two rolling members, rolling on a first rolling track secured to the support and on a second rolling track secured to the pendular body. Where appropriate, each pendulum body can be formed by two pendulum masses integral axially surrounding the support, so that there is successively axially speaking: a first pendulum mass, the support, and a second pendulum mass. The second raceway can be formed by an edge of a connecting member connecting the pendulum masses of a pendulum body. As a variant, each rolling member cooperates with two second rolling tracks, each second rolling track being formed in a pendular mass of the pendular body. Other types of pendulum damping devices are possible, for example a pendulum damping device as described in application FR 3 020 848 or in application WO 2017/072338.

In all of the foregoing, the torque transmission device may comprise a clutch, being arranged so as to be crossed by the couple using the first torque path and by the couple using the second torque path. The component output part can then be rigidly connected to the input of this clutch. The clutch can be a manual transmission clutch.

Alternatively, it may be a lockup clutch of an automatic transmission.

In another variant, it can be a clutch of a hybrid transmission. The clutch can be a simple, dry or wet clutch. Alternatively, it may be a double clutch.

When the clutch is a wet clutch, the clutch may include a plurality of input lamellae cooperating with output lamellae to transmit the torque. The clutch and the first shock absorber can succeed one another radially.

In all of the above, the device may be devoid of planetary gear. More specifically, no planetary gear is for example present in the powertrain.

In all of the above, the first damper can use a friction means, for example a friction washer, between its inlet and its outlet.

In all of the above, the first torque path can comprise one or more components mounted in series with the first damper, or be devoid of such component (s) mounted in series with the first damper .

The first damper and the component implementing the fluid coupling are for example arranged in the same housing.

According to a first example of implementation of the invention, the device comprises a housing containing the first damper, the clutch, the component and, if necessary, the pendulum damping system. The housing can be filled with oil and provide a seal against the outside. This box can be fixed relative to the casing of the engine of the powertrain or be fixed relative to the casing of the gearbox of this powertrain. This gearbox can occupy the axial space between the crankshaft and the gearbox.

According to this first example of implementation, the oil contained in the housing can: allow actuation, cooling, and lubrication of the clutch, lubrication of the pendulum damping device, when the latter is present, the lubrication of the first shock absorber, and the operation of the component. This makes best use of the presence of oil.

Still according to this first example of implementation, to supply this oil, one or more channels can be formed through the clutch support, these channels joining, for example, in a common trunk formed through a wall of the housing, for example the wall of this box on the crankshaft side or the wall of the box on the gearbox side. The circulation of oil in the common trunk and the channels is for example caused by a pump.

Still according to this first example of implementation, the sealing of the housing relative to the outside can be obtained via a single dynamic seal, the latter being for example guided by a ball bearing located at a small diameter. Such a seal has the advantage of generating little friction. This dynamic seal is for example disposed on the radially inner wall of the housing, for example at the end of this wall which faces the crankshaft or at the end of this wall which faces the gearbox.

According to this first example of implementation or independently, the clutch and the actuator can be offset axially. The clutch can be located on the side of the crankshaft while the component is located on the side of the gearbox. The clutch and the first shock absorber can succeed one another radially.

In particular according to the first example of implementation, and in a particular embodiment: - the clutch and the component succeed one another axially, - the first damper is radially outside the clutch, - the first damper and the clutch are placed on the side of the crankshaft, and - the component is placed on the side of the gearbox.

When the first damper is arranged on the side of the crankshaft, the first inlet can be rigidly fixed to a connecting flange, for example a flexible plate (flexplate), to the crankshaft.

According to this first example, of implementation, the second damper can be contained in another housing, distant from the enclosing housing: the first damper, the clutch, the component and the pendulum damping device when the latter is present.

According to a second example of implementation, the torque transmission device always comprises a housing and the latter contains: the clutch, the component, and where appropriate the pendulum damping device. This housing can be arranged axially between the crankshaft and the gearbox. This case is for example filled with oil and has a seal with respect to the outside. The oil contained in this housing can: allow the actuation, cooling, and lubrication of the clutch, lubrication of the pendulum damping device, when the latter is present, and the operation of the component. The first damper can then be placed outside this housing. The first damper is for example arranged in an axial space positioned between the crankshaft and the housing, while the housing is positioned axially between this space and the gearbox. The radially outer wall of the housing is for example positioned at a radial distance less than that at which the springs of the first damper are arranged.

According to this second example of implementation, the first damper can then be fixed directly to the crankshaft, the first inlet being thus directly fixed to this crankshaft, without any intermediate part.

The housing in which the clutch, the component and, if applicable, the pendulum damping device are contained, may be fixed relative to the casing of the engine of the powertrain or may be fixed relative to the casing of the gearbox of this powertrain.

The mechanical connection between: the input of the first shock absorber and the input part of the component can be done via a shaft concentric with the input shaft of the gearbox, while the mechanical connection between the output of the first shock absorber and the component output part can be done via another shaft concentric with the aforementioned trees. One of these connecting shafts is, for example, arranged inside the other of these connecting shafts.

Still according to this second example of implementation, to supply this oil, one or more channels can be formed through the clutch support, these channels joining, for example, in a common trunk formed through a wall of the housing, for example the wall of this box on the side of the gearbox or the wall of this box on the side of the first shock absorber. The circulation of oil in the common trunk and the channels is for example caused by a pump.

Still according to this second example of implementation, the sealing of the casing with respect to the exterior can be obtained via several separate seals. Some of these seals are for example arranged on the side of the axial space containing the first damper while others of these seals are arranged on the side of the gearbox. One or more steel washers are, for example, combined with one or more lip finishing joints, to ensure this seal.

According to this second example of implementation or independently, the clutch and the component can succeed one another radially. The clutch can be arranged radially on the outside relative to the component.

According to this second example of implementation, the first damper and the clutch can succeed one another radially.

In particular according to the second example of implementation, and in a particular embodiment: - the clutch and the component succeed one another radially, the clutch being disposed radially outside the component, - the first damper and the clutch succeed one another axially, - the first damper is arranged on the side of the crankshaft, and - the clutch and the component are arranged on the side of the gearbox.

According to the first or the second exemplary embodiment above, but in particular according to the second exemplary embodiment, the torque transmission device can comprise an electric motor for driving the vehicle.

This electric drive motor can comprise, in a known manner, a stator and a rotor.

The electric motor is for example a brushless machine.

The rotor can be rigidly coupled to the clutch outlet. In such a case, the electric drive motor allows a purely electric drive via the powertrain.

Alternatively, the rotor can be rigidly coupled to the crankshaft. In such a case, the electric drive motor makes it possible to start the engine of the powertrain, to provide a parking aid or even to provide a stop-start function.

When the electric drive motor is present, it can be arranged outside the housing, so as not to be in contact with the oil contained in this housing.

In all of the above, the actuator can be controlled by a control unit, for example integrated into the engine control unit or the transmission control unit.

In all of the above, the device may include a system for selectively closing the fluid communication between the component and the additional component.

This interruption in fluid communication can be performed to improve the efficiency of the powertrain when the presence of the second damper is not necessary.

Thus, for example, when starting the heat engine, this engine is capable of generating significant acyclisms leading to the saturation of the first damper. Within the meaning of the present application, the starting of the thermal engine corresponds in particular to a speed increase up to 800 rpm. The low stiffness provided by the presence of the second damper with negative non-linear stiffness facilitates this saturation of the first damper. The interruption of the fluid communication between the component and the additional component, which amounts to disconnecting the second damper from the device, makes it possible to avoid the degradation at start-up which would be caused by the presence of the second damper.

Due to this interruption in the fluid communication between the component and the additional component, the displacement of fluid which takes place in the component and which corresponds to a relative displacement of the inlet part with respect to the outlet part can be made impossible, except for leaks. As a result, the component input part is made immobile relative to the component output part, so that a high value stiffness is arranged in parallel with the first damper. The ratio between this stiffness then existing within the component and the first stiffness is for example of the order of 100. This thus remedies the problems of strong acyclisms at the start of the heat engine and their consequences on the first damper.

When the system blocks the fluid communication between the component and the additional component, no exchange of fluid can be possible within the component, nor within the additional component. Interruption of fluid communication between the component and the additional component may also or alternatively be desirable at high speeds, so as to decouple the additional component from the component. Within the meaning of the present application, the high speeds are, for example, speeds at the crankshaft greater than 3000 rpm or 3500 rpm. The interruption of the fluid communication between the component and the additional component may also or alternatively be desirable in the event of an abrupt variation in the average torque supplied by the heat engine. Within the meaning of the present application, a brutal variation of this average torque is for example a variation of the order of 1000 Nm / s. Indeed, this sudden variation can quickly modify the elastic deformation system, in particular the springs, of the second shock absorber, and thus affect their integrity. Disconnection of the second damper in such a case is then desirable. Furthermore, in the event of such a sudden variation in the average torque, the negative stiffness provided by the second damper can confer on the torque transmission device worse filtering performance than in a torque transmission device without such a second shock absorber.

When the fluid communication is interrupted in such a case of sudden variation of the average torque supplied by the heat engine or for high speeds of this heat engine: - no fluid exchange may be possible, apart from leaks, between the component and the additional component, - a fluid exchange may be possible within the component, and - no fluid exchange may be possible, apart from leaks, within the additional component.

The circulation of fluid within the component can allow the existence of a pressure drop which improves the filtering performance of torsional oscillations linked to acyclisms of the torque transmission device.

Thus, the selective obturation system can be configured to present: a configuration allowing fluid communication between the component and the additional component, and at least one: - of a configuration making it impossible to exchange fluid between the component and the additional component, the exchange of fluid within the component, and the exchange of fluid within the additional component, and - of a configuration making it impossible to exchange fluid between the component and the additional component, as well as the exchange of fluid within the additional component but making possible the exchange of fluid within the component. The additional actuator may include a selective shutter distributor. This selective shutter distributor can be in three positions: - a first position allowing fluid communication between the component and the additional component, - a second position making it impossible to exchange fluid between the component and the additional component, the exchange of fluid within the component, and the exchange of fluid within the additional component, and - a third position making it impossible to exchange fluid between the component and the additional component, as well as the exchange of fluid within the component additional but making possible the exchange of fluid within the component.

As mentioned above, the second position of the selective shutter distributor can be particularly suitable for starting the engine while the third position of the selective shutter distributor can be particularly suitable in the event that a sudden variation in the average torque supplied by the engine thermal occurs or for high speeds. The additional actuator can be controlled by the engine control unit or by the transmission control unit, and the detection of one of the preceding cases can lead to the passage from the first position to one of the second and third position.

Fluid communication between the component and the additional component can be done by means of two pipes extending in parallel between the component and the additional component. In the first position of the selective shutter distributor, the flow of fluid from the component to the additional component takes place in one of these pipes while the flow of fluid from the additional component to the component takes place in the other of these behaviors.

In the second position of the distributor, no fluid flow is possible in any of the pipes, the fluid then remaining static in the component and in the additional component. This second position of the distributor can correspond to the starting of the heat engine.

In the third position of the distributor, the portion of a pipe opening into the component is looped back over the portion of the other pipe opening into the component, so that the exchange of fluid is possible within the component. On the other hand, in this third position of the distributor, the portion of one of the pipes opening into the additional component is not looped over the portion of the other of the pipes opening into the additional component, so that the exchange of fluid is not possible within this additional component. This third position of the distributor can correspond to the operation of the heat engine at high speeds or to a sudden variation in the average torque supplied by the heat engine.

The different states of the two pipes allowing fluid communication between the component and the additional component which have just been mentioned can alternatively be obtained other than via a distributor. Another subject of the invention, according to another of its aspects, is a method for controlling the fluid communication between a component and an additional component of a torque transmission device, capable of being disposed between the crankshaft and the gearbox. speeds of a vehicle powertrain, the device comprising: - a first torque path through a first damper having a first stiffness which is linear, in particular positive - a second torque path through a component implementing fluid coupling , this component comprising an inlet part and an outlet part, movable with respect to each other in fluid, the inlet part being able to be rigidly connected to the crankshaft, - a second damper having a second stiffness which is non-linear this second damper interacts with the component so as to generate in the second torque path a compensating torque tion of torsional oscillations linked to acyclisms, and - an actuator acting on all or part of the operating range of the device on the second shock absorber so as to maintain or bring the second shock absorber back into a plurality of positions in which the second stiffness is negative, - an additional component implementing an additional fluid coupling, this additional component comprising an additional inlet part and an additional outlet part, movable relative to each other in fluid, the component and the additional component being in selective fluid communication, the relative displacement of the additional input part with respect to the additional output part leading in particular to the displacement of the second damper from an unstable equilibrium position, and - a shutter system selective of the fluid communication between the component and the additional component, process dice in which the state of the torque transmission device is detected and in which the fluid communication between the component and the additional component is allowed or not depending on the detected state. The detected state can be a start of the engine, or the operation of this engine at high speeds, or the sudden change in the average torque supplied by this engine.

When none of these states is detected, possible communication is allowed between the component and the additional component.

When one of these states is detected, the fluid communication is interrupted between the component and the additional component.

When the detected state is the sudden variation of the average torque supplied by the heat engine or of high speed values, the fluid communication is interrupted between the component and the additional component but an exchange of fluid within the component may be possible, as already mentioned above. The invention will be better understood on reading the following of a non-limiting example of implementation thereof and on examining the appended drawing in which: - Figure 1 schematically represents a powertrain of vehicle comprising a torque transmission device according to the invention, - Figure 2 is a sectional view of a part of a torque transmission device according to a first embodiment of the invention, - the figures 3 to 5 represent the relative displacement within the additional component of the device when the average torque supplied by the engine of the powertrain increases and that torsional oscillations propagate, and the corresponding correction carried out by the actuator, - Figures 6 to 8 represent the relative displacement within the additional component of the device when the average torque supplied by the engine of the powertrain decreases and that d torsional oscillations propagate, and the corresponding correction made by the actuator, - Figures 9 and 10 show two variants of pendulum damping system that can be integrated into the device of Figures 1 to 8, - Figures 11 and 12 represent a variant of a torque transmission device according to the first example of implementation of the invention, - Figures 13 and 14 show a torque transmission device according to a second example of implementation of the invention, and - Figures 15 and 16 are two variants of a particular aspect of a torque transmission device according to the second embodiment of the invention, - Figure 17 shows a detail of the torque transmission device of the figures 3 to 8, in which the fluid communication is interrupted between the component and the additional component, - Figure 18 shows a detail of the transmission device torque of FIGS. 3 to 8 in which the fluid communication is interrupted otherwise between the component and the additional component, and - FIG. 19 is seen similar to FIG. 1 of a torque transmission device according to another example of implementation of the invention

FIG. 1 shows schematically a powertrain 1 of a vehicle comprising a torque transmission device 2.

This powertrain 1 comprises a heat engine 3, for example petrol or diesel, which may be two, three, four or six cylinders. In known manner, this engine 3 rotates a crankshaft 4 which is arranged at the input of the torque transmission device 2.

Downstream of the torque transmission device 2, there is a gearbox 7.

Part of the torque transmission device 2 is for example received in a housing 8, visible in FIG. 2, which occupies the axial space between the crankshaft 4 and the gearbox 7. The powertrain 1 also comprises a shaft 5 gearbox input, this shaft 5 defining an axis of rotation X for the torque transmission device 2.

The torque transmission device 2 will now be described in more detail.

This torque transmission device 2 here defines two different torque paths between the crankshaft 4 and the gearbox 7.

A first torque path passes through a first damper 10 while a second torque path, also shown in FIG. 1, passes through a component 20 implementing fluid coupling. The first and second paths are here parallel. It can be seen in FIG. 2 that the first damper 10 comprises an inlet 13 and an outlet 14. The first damper 10 here comprises two stages of springs arranged in series. Each spring stage comprises several helical springs mounted in parallel. These coil springs are for example straight springs. In a variant, a single stage of springs is present in the first damper 10. This single stage of springs then uses springs in parallel. According to one or other of these variants, the first damper 10 comprises a first linear stiffness, for example between 12 Nm / ° and 20Nm / °. The output of the first damper 10 is here rigidly connected to a clutch 6.

An example of component 20 is shown in FIGS. 3 to 8. This component 20 is a rotary valve comprising an enclosure 30 defining a chamber 31 filled with a fluid, for example oil, within which is movable in rotation around an axis parallel to the axis X a body 32. The body 32 here defines an input part for the component 20, while the enclosure 30 defines an output part for the component 20, in other words the body 32 is located upstream of the enclosure 30 in the direction of torque transmission from the crankshaft 4 to the gearbox 7.

As can be seen in Figures 3 to 8, the wall of the chamber 31 includes recesses 35 and the body 32 carries a plurality of teeth 36, each tooth 36 being received in a recess 35. Elsewhere than at the teeth 36 and recesses 35, the wall of the body 32 can come into contact, with a play of displacement near, of the wall of the chamber 31.

The component 20 is in fluid communication with an additional component 21 which is offset relative to the component 20. This additional component 21 implements an additional fluid coupling between an additional inlet part 40 and an additional outlet part 41, in order to transmit a force to a second damper 11.

In the example described, the additional component 21 is a linear cylinder.

The additional input part 40 is here an enclosure defining a chamber 45. In this fluid-filled enclosure is movable the additional output part 41 which is in the example described a rod movable along an axis Y, which is for example parallel to the axis X of the powertrain. The rod 41 here carries a piston 42 sealingly delimiting two compartments 43 and 44 in the chamber 45.

As can be seen in FIGS. 3 to 8, the component 20 is in fluid communication with the additional component 21. This fluid communication here implements two pipes 49. These pipes 49 both open into the chamber 30, in each recess 35. One of these pipes is for example connected to each recess 35 on the same side of the teeth 36 while the other of these pipes 49 is connected to each recess 35 on the other side of the teeth 36. At their other end, one of these pipes 49 opens into a compartment 43 of the additional component 21 while the other pipe 49 opens into the other compartment 44 of this additional component.

It can be seen that, in the example of FIGS. 3 to 8, this fluid communication between the component 20 and the additional component 21 is selective, taking place through a distributor 50 capable of interrupting or modifying the fluid communication. Such an interruption occurs for example at high speeds of the heat engine or when starting this engine or during a sudden change in the average torque supplied by the heat engine, as will be described later. Oil can thus flow successively through component 20 and through additional component 21, depending on the state of the distributor 50.

In the variant of FIG. 19, no distributor is disposed at the level of the pipes 49.

As can be seen in the various figures, the second damper 11 interacts with the rod 41 of the additional component 21 during its movement.

The second damper î 1 here comprises several springs 52. Each spring 52 is interposed between the rod 41 of the additional component 21 and a wall of a housing 53 in which the additional component 21 and the second damper 11 are arranged. This box 53 is for example filled with oil which can communicate with that present in the additional component 21.

The wall of the housing 53 is for example integral with a frame being the casing of the heat engine.

The housing 53 is remote from the aforementioned housing 8 which contains the first damper 10 and the clutch 6, in the example of FIG. 2.

The housing 8 comprises in the example of FIG. 2: the first damper 10 and the clutch 6 and the component 20.

In the example considered, the second damper 11 comprises four springs 52. One of these springs 52 extends between a first end of the rod 41 and a first wall 56 of the housing 53, another of these springs 52 s' extends between the first end of the rod 41 and a second wall 57 of the housing 53, opposite the first wall 56, another of these springs 52 extends between a second end of the rod 41, opposite the first end, and the first wall 56, and another of these springs 52 extends between the second end of the rod 41 and the second wall 57. The actuator 12 comprises in the example considered a proportional distributor 60, as well as a reservoir 61 of oil at atmospheric pressure and a reservoir 62 of pressurized oil, for example at a pressure of value between 10 and 100 bars, and preferably between 30 and 60 bar.

This proportional distributor 60 can take three positions, namely: - a first position represented in FIGS. 3, 4, and 8, in which it puts in fluid communication the compartment 43 to the tank 61, and the compartment 44 to the tank 62, - a second position represented in FIG. 5 in which it places the compartment 43 in fluid communication with the reservoir 62 while the compartment 44 is in fluid communication with the reservoir 61, and - a third position represented in FIGS. 6 and 7 in which the tanks 61 and 62 are disconnected from the compartments 43 and 44.

The torque transmission device 2 can also include, inside the housing 8 containing the clutch 6 and the first damper 10, a pendular damping system 25, two variants of which are shown in FIGS. 9 and 10.

The pendulum damping system 25 comprises, in a known manner, a support 26 and a plurality of pendulum bodies 27 which are circumferentially successive. Each pendulum body 27 is in the two variants shown formed by two pendulum masses 28 axially framing the support 26 and secured to each other, for example by rivets 30 in the case of Figure 5 or by spacers 31 in the case of the figure 4, the latter also defining a running track.

The support 26 is for example rigidly coupled to the outlet 14 of the first damper 10.

The operation of the torque transmission device 2 will now be described.

The path of the torque through the device 2 is as follows.

The average torque supplied by the heat engine transits exclusively by the first path through the first damper 10.

The path of the torque through the device 2 is as follows. The average torque supplied by the heat engine transits exclusively by the first path through the first damper 10.

When a torsional oscillation propagates due to acyclism, this torsional oscillation leads to a deformation of the springs of the first shock absorber 10. Due to the deformation of the first shock absorber 10, a relative displacement takes place within the component 20 between the body 32 and the enclosure 30 defining the chamber 31. Because of this displacement, each tooth 36 approaches a circumferential end of the recess 35 in which it is received, leaving the position of FIG. 3 or 6 in which it is midway between these circumferential ends of the recess 35. Due to this displacement, the portion of the recess 35 disposed between the tooth 36 and the circumferential end of the recess 35 whose tooth 36 approaches sees its volume decrease while the other portion of this step 35 sees its volume increase. These variations in volume lead to a transfer of fluid from the component 20 through the distributor 50 to the compartment 44 of the additional component 21, this compartment 44 seeing its volume increase due to the fluid thus received while these same variations in volume lead to a transfer of fluid from compartment 43 of additional component 21 through distributor 50 to component 20.

As can be seen in FIG. 4, this deformation of the first damper 10 thus leads to a displacement of the rod 41 which results in a displacement of the springs 52 of the second damper 11. The latter leave their unstable equilibrium position in FIG. 4 , occupying a plurality of positions in which their stiffness is negative. The deformation of these springs 52 generates a force, which via the pipes 49, generates a torque in the component 20. The torque thus generated is applied in the second path and has a sign opposite to that applied in the first torque path because deformation of the first damper 10.

The movement of the springs 52 from their unstable equilibrium position can lead these springs 52 to occupy positions in which the second damper 11 no longer exhibits negative stiffness and in which these second springs can no longer oscillate around this equilibrium position unstable. In addition, certain positions of these springs 52 may correspond to an abutment of the piston 42 against the wall of the chamber 45, which could damage this piston and this wall. To prevent such positions from being occupied by the springs 52, the control of the actuator 12, by the engine control unit or the transmission control unit, consists in bringing the distributor 60 to the second position. For this second position of the distributor 60, pressurized fluid is injected from the pressure tank 62 into the compartment 43 to return the piston 42 to the position in FIG. 3 in which each compartment 43 and 44 has substantially the same volume. The return to this equilibrium position of the piston 42 in the chamber 40 is illustrated in FIG. 5. The springs 52 will then oscillate again around their unstable equilibrium position in positions in which the second stiffness is negative. The invention is not limited to the examples which have just been described.

We will now describe with reference to Figures 11 and 12 a variant of the first example of implementation of the invention.

As can be seen in FIG. 11 or 12, the first damper 10, the clutch 6, the component 20 and the pendulum damping device 25 are contained in the housing 8, and in this housing: - the clutch 6 and the component 20 succeed one another axially, - the first damper 10 is radially outside the clutch 6, - the first damper 10 and the clutch 6 are arranged on the side of the crankshaft 4, and - the component 20 is disposed on the side of the gearbox.

As can be seen in Figure 11, channels are provided in the wall 22 of the housing 8 to bring the oil under pressure into the interior of the housing. These channels can extend into the clutch support 23, or branch out inside this clutch support 23.

The housing 8 is here fixed relative to the casing of the gearbox of this powertrain.

According to a second example of implementation, which will now be described with reference to Figures 13 to 16, the housing 8 no longer contains the first damper 10. In Figures 13 to 16, the housing 8 contains the component 20, the clutch 6 and the pendulum damping device 25.

As can be seen in these figures, the first damper 10 is then disposed outside the housing 8, being arranged in an axial space positioned between the crankshaft 4 and the housing 8, while the housing 8 is positioned axially between this space and the gearbox 7. The first damper 10 is here fixed directly on the crankshaft 4, that is to say that the first inlet 13 is directly fixed on this crankshaft 4, without any intermediate part. It can also be seen in FIGS. 13 and 14 that the springs of the first damper 10 are here arranged at a radial distance greater than that at which the radially outer wall of the housing 8 is arranged.

As already mentioned, the housing 8 is here fixed relative to the casing of the engine of the powertrain and to the casing of the gearbox of this powertrain.

It can be seen in FIGS. 13 and 14 that the clutch 6 and the component 20 succeed one another radially. The clutch 6 is here arranged radially on the outside with respect to the component 20.

In FIGS. 13 and 14: - the clutch 6 and the component 20 succeed one another radially, the clutch 6 being arranged radially outside the component 20, - the first damper 10 and the clutch 6 succeed one another axially, - the first damper 10 is disposed on the side of the crankshaft 4, and - the clutch 6 and the component 20 are disposed ducôté of the gearbox.

In the example of FIGS. 13 and 14, one or more oil supply channels are formed through the clutch support 23, these channels joining, for example, in a common trunk 40 formed through a wall 22 of the housing. 8. This wall 22 is in the example considered the wall on the side of the first damper 10. The sealing of the housing 8 with respect to the outside can be obtained via several separate seals 55 and 56. The seal 55 is here arranged with the side of the axial space containing the first damper 10 while the seal 56 is disposed on the side of the gearbox 7. In FIGS. 13 and 14, the mechanical connection between the inlet of the first damper 10 and the body 32 of component 20 is made via a shaft 46 concentric with the input shaft 5 of the gearbox 7, while the mechanical connection between the outlet of the first damper 10 and the enclosure 30 of component 20 is made via another tree 45, concentriq eu with the aforementioned trees. It can be seen in FIGS. 13 and 14 that the shaft 45 is arranged around the shaft 46.

Figures 15 and 16 very schematically represent a particular case of the second embodiment which has just been described with reference to Figures 13 and 14. In these Figures 15 and 16, we see that an electric motor driving the vehicle is present. This electric drive motor here comprises, in a known manner, a stator 50 and a rotor 51.

In the example of FIGS. 15 and 16, the electric motor for driving the vehicle is disposed outside of the box 8, being radially outside of this box 8.

In FIG. 15, it can be seen that the rotor 51 is rigidly coupled to the output of the clutch 6.

As a variant, in FIG. 16, the rotor 51 is rigidly coupled to the crankshaft 4. The electric motor for driving the vehicle is for example a brushless motor (brushless) providing a nominal power of between 5 kW and 100 kW, in particular between 20 kW and 80 kW.

An electric motor for driving the vehicle may also be present in the case of a torque transmission device according to the first example of implementation of the invention, although such a case is not shown.

The selective shutter distributor 50 is in the example of FIGS. 1 to 18 a distributor with three positions. The first position allows fluid communication between the component 20 and the additional component 21. Each pipe 49 thus allows the circulation of fluid between the recesses 35 of the chamber 31 of the component 20 and a respective compartment 43, 44 of the chamber 45 of the component additional 21. In each of Figures 3 to 8, the selective shutter distributor 50 has this first state.

The second position of the selective shutter distributor 50 is shown in FIG. 17. In this position, the exchange of fluid between the component 20 and the additional component 21 as well as the exchange of fluid within the component 20 and that the 'exchange of fluid within the additional component is made impossible. In this second position, as can be seen in FIG. 17, each pipe 49 is interrupted at the level of the selective shutter distributor. This second position makes it possible to disconnect the second damper 11 from the torque transmission device 2, for example when starting the heat engine 3. In this second position, the input part 32 of the component 20 is locked in rotation relative to the outlet part 30 of the component 20, so that a high stiffness is added in parallel with the first damper 10.

The third position of the selective shutter distributor 50 is shown in FIG. 18. This position differs from the second position in FIG. 17 in that the exchange of fluid is possible in component 20. This exchange of fluid takes place via the portion of one of the conduits 49 which opens into the recesses 35 and via the portion of the other of these conduits 49 which opens into these recesses 35, these two portions being looped back at the level of the selective shutter distributor 50. This third position disconnects the second damper 11 from the torque transmission device 2, This third position is for example occupied by the selective shutter distributor when a sudden variation in the average torque supplied by the heat engine 3 is detected or for high speeds of the heat engine.

Claims (11)

claims 1. Torque transmission device (2), capable of being arranged between the crankshaft (4) and the gearbox (7) of a vehicle powertrain (1), the device (2) comprising: - a first torque path through a first damper (10) having a first stiffness which is linear, - a second torque path through a component (20) implementing a fluid coupling, this component comprising an input part (32) and an outlet part (30), movable with respect to each other in fluid, the inlet part (32) being able to be rigidly connected to the crankshaft (4), - a second damper (11) having a second stiffness which is non-linear, this second damper (11) interacting with the component (20) so as to generate in the second torque path a torque for compensating for torsional oscillations linked to acyclic movements, and - a actuator (12) acting on all or part of the range of f actuation of the device on the second shock absorber (11) so as to maintain or return the second shock absorber to a plurality of positions in which the second stiffness is negative, - an additional component (21) implementing an additional fluid coupling, this additional component comprising an additional inlet part (40) and an additional outlet part (41), movable with respect to each other in fluid, the component (20) and the additional component (51) being in selective fluid communication, the relative displacement of the additional input part (40) relative to the additional output part (41) leading in particular to the displacement of the second damper (11) from an unstable equilibrium position, and - a system selective closure (50) of the fluid communication between the component (20) and the additional component (21). 2. Device according to claim 1, the selective shutter system (50) being configured to present: a configuration allowing fluid communication between the component (20) and the additional component (21), and at least one: - of a configuration making it impossible to exchange the fluid between the component (20) and the additional component (21), the exchange of fluid within the component (20), and the exchange of fluid within the additional component ( 21), and - of a configuration making it impossible to exchange the fluid between the component (20) and the additional component (21), as well as the exchange of fluid within the additional component (21) but making it possible to fluid exchange within the component (20). 3. Device according to claim 1 or 2, the additional actuator comprising a selective shutter distributor (50). 4. Device according to claim 3, the selective shutter distributor (50) being in three positions: - a first position allowing fluid communication between the component (20) and the additional component (21), - a second position making it impossible the exchange of fluid between the component (20) and the additional component (21), the exchange of fluid within the component (20), and the exchange of fluid within the additional component (21), and - a third position making it impossible to exchange the fluid between the component (20) and the additional component (21), as well as the exchange of fluid within the additional component (21) but making possible the exchange of fluid within the component (20). 5. Device according to claim 4, the fluid communication between the component (20) and the additional component (21) being effected by means of two conduits (49) extending in parallel between the component (20) and the additional component (21), and: - in the first position of the selective shutter distributor (50), the flow of fluid from the component (20) to the additional component (21) taking place in one of these pipes (49) while the flow of fluid from the additional component (21) to the component (20) takes place in the other of these pipes (49), - in the second position of the selective shutter distributor (50), no flow of fluid is not possible in any of the conduits (49), the fluid then remaining static in the component (20) and in the additional component (21), and - in the third position of the selective shutter distributor (50), the portion of a pipe (49) opening into the component (20) es t looped back onto the portion of the other pipe (49) opening into the component (20), so that the exchange of fluid is possible within the component (20). 6. Device according to any one of the preceding claims, the second shock absorber (11) comprising an elastic deformation system (53), this system (53) being on the one hand fixed to one of the additional input part (41) and the additional outlet part (40), and on the other hand on a frame (53). 7. Device according to claim 6, the elastic deformation system being prestressed in the unstable equilibrium position of the second damper (11). 8. Device according to claim 6 or 7, the additional outlet part (41) being a cylinder rod and the additional inlet part (40) defining a chamber (42) filled with fluid inside which moves the cylinder rod (41), the cylinder rod (41) moving along an axis (Y) and the elastic deformation system comprising springs (52), each spring (52) extending orthogonally to this axis (Y ), in the unstable equilibrium position of the second damper (11). 9. Device according to any one of claims 3 to 8, the actuator (12) being configured to selectively inject pressurized fluid into the additional component (21), the relative movement of the additional input part ( 40) relative to the additional output part (41) being caused by the relative movement of the input part (32) relative to the output part (30), transmitted by the fluid communication between the component (20) and the additional component (21), and the actuator (12) injecting pressurized fluid into the additional component (21) to oppose all or part of this relative displacement of the additional input part (40) by relative to the additional outlet part (41). 10. Method for controlling the fluid communication between a component (20) and an additional component (21) of a torque transmission device (2), capable of being disposed between the crankshaft (4) and the gearbox ( 7) of a vehicle powertrain (1), the device (2) comprising: - a first torque path through a first damper (10) having a first stiffness which is linear, - a second torque path through a component (20) implementing a fluid coupling, this component comprising an inlet part (32) and an outlet part (30), movable relative to each other in fluid, the part inlet (32) being able to be rigidly connected to the crankshaft (4), - a second damper (11) having a second stiffness which is non-linear, this second damper (11) interacting with the component (20) so as to generate in the second torque path a compensation torque torsional oscillations linked to acyclisms, - an actuator (12) acting on all or part of the operating range of the device on the second shock absorber (11) so as to maintain or return the second shock absorber to a plurality of positions in which the second stiffness is negative, - an additional component (21) implementing an additional fluid coupling, this additional component comprising an additional inlet part (40) and an additional outlet part (41), movable one with respect to the other in fluid, the component (20) and the additional component (21) being in selective fluid communication, the relative movement of the additional inlet part (40) relative to the additional outlet part (41) leading in particular to the displacement of the second damper (11) from an unstable equilibrium position, and - a selective shutter system (50) of the fluid communication between the compound ant (20) and the additional component (21), method in which: - it detects what is the state of the torque transmission device (2), and - it is allowed or not via the selective shutter system (50) fluid communication between the component and the additional component according to the detected state. 11. The method of claim 10, wherein a start of the heat engine (3), or the operation of this heat engine (3) at high speeds, or the sudden variation of the average torque supplied by this engine (3) is detected. ).