Torque transmission device for a motor vehicle

Abstract

Torque transmission device for a motor vehicle, comprising a torque input element (6, 7), a torque output element (24, 8), at least one first elastic organ (10a) and at least one second elastic organ (10b) connected in series via a phase-balancing organ (29) so that the first and the second elastic organ (10a, 10b) deform in phase with each other, wherein the phase adjustment device (29) is movable towards the torque input element (6, 7) and towards the torque output element (24, 8), the first elastic organ (10a) is located between the torque input element (6, 7) and the phase balancing element (29) and is designed to act over a first angular range opposite to the rotation of the torque input element (6, 7) to the phase balancing organ (29), and the second elastic organ (10b) is located between the phase balancing organ (29) and the torque output element (24, 8) and is designed to act against the rotation of the torque output element (24, 8) towards the phase balancing organ (24), characterized by the fact that the torque transmission device has at least one third elastic element (10c) which is attached parallel to the first elastic element (10a) with circumferential clearance between the torque input element (6, 7) and the phase balancing element (29) and is designed to act against the rotation of the torque input element (6, 7) to the phase balancing element (24) over a second angular range which is smaller than the first angular range. wherein the third elastic organ is arranged on a diameter that differs from that on which the first and / or the second elastic organ are arranged, wherein the third elastic organ (10c) lies radially within the first elastic organ (10a) and the second elastic organ (10b), and wherein the torque transmission device has an annular auxiliary cover (46) which is fitted with circumferential clearance with respect to the phase balancing element (29), wherein the third elastic element (10c) is fitted between the auxiliary cover (46) and the torque input element (6, 7).

Description

[0001] The present invention relates to a torque transmission device for a motor vehicle.

[0002] Such a device generally comprises a torque input element intended to be coupled directly or indirectly to a crankshaft, a torque output element intended to be coupled to an input shaft of a transmission, and a first group of elastic members mounted between the torque input and torque output elements and acting against the rotation of one of the torque input and the torque output elements relative to the other.

[0003] If the torque transmission device is a torque transmission device of the LTD (Long Travel Damper) type, it has several pairs of elastic elements, the elastic elements of one and the same pair being connected in series via a phase adjustment element so that the elastic elements of each group deform in phase with each other.

[0004] To enable the damping of high torques, it is known to add a second group of elastic members to the aforementioned device. These members are mounted with play parallel to the first group of elastic members between the torque input and torque output elements and are designed to act against the rotation of one of the input elements over a limited angular range, particularly in the end angular position. The angular path or angular offset, designated α, of the torque input element with respect to the torque output element is defined relative to a rest position (α = 0), in which no torque is transmitted by the device.

[0005] The second group of elastic elements allows to increase the stiffness of the damping device in the angular end position, i.e. for a large angular offset α of the torque input element with respect to the torque output element (or vice versa).

[0006] The document US 2010 / 0133063 A1 discloses a torque transmission device of the LTD type with two groups of elastic members arranged in parallel, the second group being activated only in the final angular position α of the torque input element with respect to the torque output element (or vice versa).

[0007] DE 101 33 694 A1 discloses a torsional vibration damper with multiple damping devices equipped with elastically deformable energy storage devices. Furthermore, an intermediate element is provided, which is arranged with a radial end portion between the contact surfaces of the energy storage devices. The intermediate element also has a support area arranged radially inward of the damping devices. An additional coil spring can be arranged within the support area.

[0008] WO 2007 / 028366 A2 discloses a damper for a torque converter, wherein the damper comprises a first spring group, a second spring group, and a third spring group. The springs of the third spring group are connected in parallel to the series-connected springs of the first and second spring groups and are arranged radially further outward from these springs.

[0009] DE 197 08 327 A1 discloses a torsional vibration damper comprising a primary part and a secondary part, as well as an intermediate disk arranged between the primary and secondary parts. Tangential compression springs are provided between the secondary part and the intermediate disk, as well as pre-damper springs arranged between the primary part and the intermediate disk.

[0010] DE 198 57 109 A1 describes a damper disk assembly with a first and a second plate element and an intermediate element arranged therebetween. The intermediate element couples to the intermediate element via a second elastic element. The first and second plate elements couple via a third elastic element. Furthermore, a damper with a first elastic element is provided, which couples a hub and the intermediate element and is arranged axially to the first plate element.

[0011] It should be noted that the representation of the function M = f(α), which defines the torque M transmitted by the device as a function of the angular displacement α, includes a first linear section with the slope Ka (for low values ​​of the angular displacement α) and a second linear section with a greater slope Kb (for high values ​​of the angular displacement α). Ka and Kb represent the angular stiffnesses of the device at the beginning and end of the angular trajectory, respectively. If K1 represents the cumulative stiffnesses of the first springs of each pair of the first group, K2 the cumulative stiffnesses of the second springs of each pair of the first group, and K3 the cumulative stiffnesses of the springs of the second group, then Ka = (K1.K2) / (K1+K2) and Kb = Ka + K3.

[0012] The invention proposes a simple, effective and economical alternative to the torque transmission devices of the prior art.

[0013] For this purpose, the invention proposes a torque transmission device for a motor vehicle, comprising a torque input element, a torque output element, at least one first elastic member and at least one second elastic member, which are connected in series via a phase adjustment member, so that the first and the second elastic member deform in phase with each other, wherein the phase adjustment member is movable relative to the torque input element and the torque output element, wherein the first elastic member is mounted between the torque input element and the phase adjustment member and is designed to act over a first angular range counter to the rotation of the torque input element relative to the phase adjustment member, and wherein the second elastic member is mounted between the phase adjustment member and the torque output element and is designed toto act against the rotation of the torque output element towards the phase adjustment element, characterized in that it comprises at least one third elastic element mounted with circumferential play parallel to the first elastic element between the torque input element and the phase adjustment element and designed to act against the rotation of the torque input element towards the phase adjustment element over a second angular range which is smaller than the first angular range, wherein the third elastic element is arranged on a diameter which is different from that on which the first and / or the second elastic element is arranged.

[0014] In another example, the third elastic organs are located on a diameter that is smaller than that on which the first elastic organs and the second elastic organs are arranged.

[0015] The first elastic member and the second elastic member are preferably arranged concentrically according to one and the same diameter.

[0016] The device preferably comprises two guide discs arranged axially on one and the other side of an annular cover, wherein the guide discs belong to the torque input element and the annular cover belongs to the torque output element or vice versa.

[0017] The annular cover may further comprise an annular portion from which tabs extend radially outward, wherein the first and second elastic members are circumferentially disposed between the tabs of the cover. The third elastic member may further be located radially outside the first elastic member and the second elastic member.

[0018] This increases the effectiveness of the filtering.

[0019] In this case, the phase adjustment member may comprise an annular portion from which at least one tab extends radially inwards, the first and second elastic members coming into contact circumferentially on one and the other side of the tab of the phase adjustment member.

[0020] The annular portion of the phase adjustment member may in particular comprise at least one window or notch serving to receive the third elastic member.

[0021] According to the invention, the third elastic member is located radially inside the first elastic member and the second elastic member.

[0022] The device comprises an annular auxiliary cover mounted with circumferential clearance to the phase adjustment member, the third elastic member being mounted between the auxiliary cover and the torque input element.

[0023] The annular auxiliary cover may have an annular portion from which at least one tab projects radially outward, the tab engaging with circumferential play in an opening or a notch of the phase adjustment member.

[0024] The annular auxiliary cover can thus be set in rotation by placing its tab at the end or bottom of the notch or opening of the phase adjustment device.

[0025] The phase adjustment member may further comprise an annular portion from which at least one tab extends radially outward, the first and second elastic members circumferentially engaging on one and the other side of the tab of the phase adjustment member, the opening or notch in which the tab of the annular auxiliary cover engages being formed in the annular portion of the phase adjustment member.

[0026] The device may comprise two auxiliary guide discs mounted on one and the other side of the auxiliary cover and pivotable with respect to the auxiliary cover, the auxiliary guide discs being rotatably coupled to the torque input element.

[0027] In this case, the torque output element or the torque input element may comprise an inner hub intended to be coupled to an input shaft of a transmission and having an annular housing in which the auxiliary guide discs, the auxiliary cover and / or the third elastic member are at least partially arranged.

[0028] Furthermore, pendulum damping means can be attached to the phase adjustment device.

[0029] The invention also relates to a hydrodynamic torque converter for a motor vehicle, characterized in that it comprises at least one device of the aforementioned type.

[0030] The invention will be better understood and further details, features, and advantages will become clearer upon reading the following description, given as a non-limiting example with reference to the accompanying drawings. In the drawings: - Fig. 1 is a schematic representation of a torque converter equipped with a torque transmission device not according to the invention, - Fig. 2 to 9 a first embodiment of the invention and in particular - Fig. 2 a perspective view of the device, - Fig. 3 and Fig. 4 perspective exploded views of the device, - Fig. 5 a detailed view of a part of the device, - Fig. 6 a half view of the device in axial section, - Fig. 7 and Fig. 8 schematic views illustrating the operation of the device, - Fig. 9 is a diagram representing the function M=f(α) which defines the torque M transmitted by the device as a function of the angular offset α between the torque input element and the phase adjustment element, - Fig. 10 to 14 an embodiment of the invention and in particular - Fig. 10 a perspective view of the device, - Fig. 11 is an exploded perspective view of the device, - Fig. 12 a perspective detailed view of a part of the device, - Fig. 13 a perspective view of the auxiliary guide discs, the auxiliary cover and the third elastic members, - Fig. 14 a view of the device in axial section.

[0031] A hydrodynamic torque converter (not according to the invention) is shown in Fig. 1 is shown schematically and partially. This converter enables the transmission of torque from the output shaft of a motor vehicle internal combustion engine, such as a crankshaft 1, to an input shaft 2 of a transmission.

[0032] The torque converter conventionally has a pulse generator impeller 3, which can hydrokinematically drive a turbine impeller 4 via an engine 5.

[0033] The pulse generator wheel 3 is coupled to the crankshaft 1, and the turbine wheel 4 is coupled to the turbine hub 6 ( Fig. 2), which is itself coupled to two guide discs 7, designated 7a and 7b.

[0034] As this is Fig. 2, the guide disc 7b and the turbine hub 6 are rotatably mounted around a grooved central hub 8 which is to be coupled to the input shaft 2 of the gearbox.

[0035] The guide disc 7a is mounted around the turbine hub 6 and secured thereto via pins 6a. The two guide discs 7a, 7b extend radially, defining an interior space 9 between them ( Fig. 6), which serves in particular to accommodate first elastic elements 10a and second elastic elements 10b, which are, for example, helical compression springs.

[0036] The guide disc 7b has a cylindrical edge 11 on its radially outer circumference, which extends towards the guide disc 7a and is fixed thereto.

[0037] The free end of the cylindrical rim 11 has tabs 13 that extend axially through holes 14 in the disc 7a. These tabs 14 are riveted to the outer periphery of the guide disc 7a and may be welded thereto to ensure the attachment of the two guide discs 7a, 7b.

[0038] The guide discs 7a, 7b conventionally have windows 15 which serve to accommodate the elastic members 10a, 10b.

[0039] A grooved hub 18 is also riveted to the rear of the guide disc 7b. This grooved hub 18 has a radial portion 19 secured to the rear of the guide disc 7b and a grooved cylindrical rim 20 extending rearwardly from the radially outer periphery of the radial portion 19.

[0040] A clutch 21 ( Fig. 1) can transmit torque from the crankshaft 1 to the guide discs 7 in a predetermined operating phase without engaging the pulse generator wheel 3 and the turbine wheel 4. This clutch 21 has an input element 22 coupled to the crankshaft 1 and an output element 23 comprising the splined hub 18.

[0041] A radially extending annular cover 24 is mounted in the interior and fastened to the central hub 8 by rivets.

[0042] As in Fig. 5, the annular cover 24 has a radially inner ring section 25, from which, for example, three tabs 26 ( Fig. 3) extend radially outwards. Each tab 26 has two opposite surfaces 27 ( Fig. 3) which serve to support the elastic members 10a, 10b and are inclined relative to each other and to the radial direction. Two stop blocks 28 extend circumferentially on one and the other side of each tab 26 at the level of its outer circumference.

[0043] The elastic members 10a, 10b are circumferentially mounted between the annular cover 24 and the guide discs 7a, 7b. In this example, the elastic members are arranged concentrically along the same diameter.

[0044] The elastic members 10a, 10b are arranged in particular in pairs. The elastic members of one and the same pair are connected in series via a common phase adjustment member 29, so that the elastic members 10a, 10b deform in phase with each other. In the embodiment illustrated in the figures, the torque converter comprises three pairs of elastic members 10a, 10b.

[0045] For each pair of elastic members 10a, 10b, depending on the direction of rotation of the guide discs 7a, 7b with respect to the annular cover 24, one of the elastic members (for example, 10a) is designed to engage, on the one hand, with the corresponding end of the windows 15 of the guide discs 7a, 7b and, on the other hand, with the phase adjustment member 29. The other elastic member (for example, 10b) is then designed to engage, on the one hand, with the phase adjustment member 29 and, on the other hand, with one of the surfaces 27 of the corresponding tab 26 of the annular cover 24.

[0046] The phase adjustment element 29 has an outer ring section 30, from which three tabs 31 extend radially inward. Each tab 31 has two opposing surfaces 32, which serve to engage the elastic elements 10a, 10b and are inclined relative to each other and to the radial direction. Two stop areas 33, which form steps, extend circumferentially on one and the other side of each tab 31.

[0047] The stop blocks 28 of the tabs 26 of the annular cover 24 can each come into contact with the stop areas 33 of the contact sections 31 of the phase adjustment element 29.

[0048] The blocks 28 and the areas 33 are positioned and dimensioned to limit the compression of the elastic members 10a, 10b and, in the case of helical springs, to prevent the coils of the springs from colliding with one another during compression, both in the direction of rotation, referred to as the direct direction, and in the opposite direction, referred to as the reverse direction. The direct direction corresponds to the operating case in which a torque is transmitted from the torque input element to the torque output element. During certain operating phases, for example, when the user abruptly releases their foot from the accelerator pedal, a resistive torque is transmitted from the torque output element to the torque input element, which can cause the phasing member 29 to rotate in the reverse direction.

[0049] The device further comprises pendulum masses 35 which are movably mounted on the radially outer circumference of an annular carrier 36, wherein the radially inner circumference of the carrier 36 is rotatably coupled to the tabs 31 via flat connecting struts 38.

[0050] The pendulum masses 35 are connected via struts 37 and rollers 39 (in Fig. 14) are movably mounted on the support 36 as is known per se, these masses 35 being intended to improve the filtering of vibrations and rotational irregularities.

[0051] The device further comprises third elastic members 10c, which are designed as bent helical compression springs and are pre-tensioned and mounted in cutouts 40 formed on the radially outer circumference of the phase adjustment member.

[0052] In this example, the elastic members 10c are located on a diameter that differs from that of the first elastic members 10a and the second elastic members 10b. In particular, the third elastic members 10c are located on a diameter that is larger than that of the first elastic members 10a and the second elastic members 10b.

[0053] The elastic members 10c further engage in openings 41 of the guide discs 7a, 7b, so that the ends of the elastic members 10c can engage the ends of the openings. Each opening 41 has a circular arc shape and a larger circumferential dimension than the elastic members 10c, so that the elastic members 10c are mounted with circumferential play or with angular play j between the guide discs 7a, 7b and the phase adjustment member 24.

[0054] During operation, the guide discs 7a, 7b and the hub 6 pivot with respect to the cover 24 and the hub 8 (in direct or reverse direction), causing the phase adjustment member 29 to rotate by an angle α with respect to the guide discs 7a, 7b.

[0055] As in Fig. 7, only the first and second elastic members 10a and 10b are active, ie they act against the rotation of the torque input element (disks 7a, 7b and hub 6) with respect to the torque output element (cover 24 and hub 8), as long as this angle α is smaller than the angular play j, ie than an angle α1.

[0056] When the entire game j is eliminated ( Fig. 8), ie when the angle α is greater than or equal to α1, the third elastic organs 10c act parallel to the elastic organs 10a.

[0057] On the diagram from Fig. 9, it can thus be seen that the curve illustrating the torque M transmitted by the device as a function of the angular displacement α includes a first linear section with a gradient Ka (for low values ​​of the angular displacement α, i.e., when α is less than α1) and a second linear section with a greater gradient Kb (for high values ​​of the angular displacement α, i.e., when α is greater than α1). Ka and Kb are the angular stiffnesses of the device at the beginning (α < α1) and at the end of the angular trajectory (α ≥ α1), respectively. If K1 is defined as the cumulative stiffness of the first springs 10a of each pair, K2 as the cumulative stiffness of the second springs 10b of each pair, and K3 as the cumulative stiffness of the third springs 10c, then Ka = (K1.K2) / (K1+K2) and Kb = [(K1+K3).K2] / [K1+K2+K3].With such a device, very high torques can be damped and transmitted with a relatively small axial and radial space requirement.

[0058] The position α=0 is defined by the rest position of the device, in which no torque is transmitted by the device.

[0059] The Fig. 10 to 14 illustrate an embodiment of the invention which differs from the embodiment described above with reference to the Fig. 1 to 9 is explained.

[0060] In this embodiment, the annular cover 24 has a radially inner ring portion 25, from which tabs 26 extend radially inward. As above, the tabs 26 are connected to the support 36 of the pendulum masses 35 via connecting struts 38. The radially inner periphery of the cover 24 further has a cylindrical and axially extending edge 42 in which circumferentially extending notches 43 are formed.

[0061] As in Fig. 14, the central hub 8 also has an annular receptacle 44 which opens out on the side of the guide disc 7b.

[0062] Mounted in this receptacle 44 is an assembly comprising two auxiliary guide discs 45, which are arranged on one side and the other of an auxiliary cover 46. The two guide discs 45 are connected to each other via cylindrical and riveted struts 47 and are connected to the guide disc 7b via the same riveted struts.

[0063] The auxiliary cover 46 is rotatable within a specific angular range with respect to the auxiliary guide discs 45. The auxiliary cover 46 has an annular portion 48, from which four tabs 49 extend radially outward. The tabs 49 engage with circumferential play or with angular play j in the notches 43 of the phase adjustment element 24. The annular portion 48 also has circular-arc-shaped elongated holes 50 ( Fig. 13), which allow the passage of the struts 47 as well as the angular deflection of the struts 47 with respect to the annular cover 46.

[0064] The ring portion 48 of the auxiliary cover 46 and the auxiliary guide discs 45 further have windows 51 in which the third elastic members 10c are pre-tensioned.

[0065] The third elastic members 10c, which are designed as bent helical compression springs as above, thus counteract the pivoting movement of the auxiliary cover 46 relative to the auxiliary guide discs 45. They also have a diameter that differs from that of the first elastic members 10a and the second elastic members 10b. In particular, the third elastic members 10c have a smaller diameter than the first elastic members 10a and the second elastic members 10b.

[0066] The operation of such an embodiment is similar to that described above. The guide discs 7a, 7b and the hub 6 pivot, particularly during operation, relative to the cover 24 and the hub 8 (in a direct or reverse direction), causing the phase adjustment element 29 to rotate by an angle α relative to the guide discs 7a, 7b.

[0067] As long as this angle α is smaller than the angular clearance j, i.e., an angle α1, only the first and second elastic members 10a and 10b are active, i.e., they act against the rotation of the torque input element (disks 7a, 7b and hub 6) to the torque output element (cover 24 and hub 8). Conversely, when all the clearance j is eliminated, i.e., when the angle α is greater than or equal to α1, the tabs 49 of the auxiliary cover 46 come into contact with the ends of the cutouts 43 of the annular cover 24, and the third elastic members 10c are then compressed so as to act parallel to the first elastic members 10a.

Claims

[1] Torque transmission device for a motor vehicle, comprising a torque input element (6, 7), a torque output element (24, 8), at least one first elastic member (10a) and at least one second elastic member (10b) connected in series via a phase adjustment member (29) so that the first and second elastic members (10a, 10b) deform in phase with each other, wherein the phase adjustment element (29) is movable relative to the torque input element (6, 7) and the torque output element (24, 8), the first elastic member (10a) is mounted between the torque input element (6, 7) and the phase adjustment element (29) and is designed to act on a first angular range counter to the rotation of the torque input element (6, 7) to the phase adjustment member (29), and the second elastic member (10b) is mounted between the phase adjustment member (29) and the torque output element (24, 8) and is designed to act against the rotation of the torque output element (24, 8) to the phase adjustment member (24), characterized by , that the torque transmission device comprises at least a third elastic member (10c) mounted with circumferential play between the torque input element (6, 7) and the phase adjustment member (29) parallel to the first elastic member (10a) and designed to act on a second angular range, which is smaller than the first angular range, against the rotation of the torque input element (6, 7) to the phase adjustment member (24), wherein the third elastic member is arranged on a diameter different from that on which the first and / or the second elastic member are arranged, wherein the third elastic member (10c) is located radially inside the first elastic member (10a) and the second elastic member (10b), and wherein the torque transmission device comprises an annular auxiliary cover (46) mounted with circumferential play with respect to the phase adjustment member (29), wherein the third elastic member (10c) is mounted between the auxiliary cover (46) and the torque input element (6, 7). [2] Device according to claim 1, characterized by in that it comprises two guide discs (7a, 7b) which are arranged axially on one side and on the other side of an annular cover (24), wherein the guide discs (7a, 7b) belong to the torque input element and the annular cover (24) belongs to the torque output element or vice versa. [3] Device according to claim 2, characterized byin that the annular cover (24) has an annular section (25) from which tabs (26) extend radially outwards, the first and second elastic members (10a, 10b) being arranged circumferentially between the tabs (26) of the cover (24). [4] Device according to one of the preceding claims, characterized by that the annular auxiliary cover (46) has an annular section (48) from which at least one tab (49) projects radially outwards, wherein the tab (49) engages with circumferential play in an opening or a notch (43) of the phase adjustment member (29). [5] Device according to one of the preceding claims, characterized byin that the phase adjustment member (29) has an annular portion (30) from which at least one tab (31) extends radially outwards, the first and second elastic members (10a, 10b) coming into contact circumferentially on one and the other side of the tab (31) of the phase adjustment member, the opening or notch (43) in which the tab (49) of the annular auxiliary cover (46) engages being formed in the annular portion (30) of the phase adjustment member (29). [6] Device according to one of the preceding claims, characterized by in that it comprises two auxiliary guide discs (45) which are mounted on one and the other side of the auxiliary cover (46) and can pivot with respect to the annular cover (46), the auxiliary guide discs (45) being rotatably coupled to the torque input element (6, 7). [7] Device according to claim 6, characterized byin that the torque output element (24, 8) or the torque input element (6, 7) has a central hub (8) which is intended to be coupled to an input shaft (2) of a transmission, and has an annular housing (44) in which the auxiliary guide discs (45), the auxiliary cover (46) and / or the third elastic member (10c) are at least partially received. [8] Device according to one of the preceding claims, characterized by that pendulum damping means (35, 36) are attached to the phase adjustment element (29). [9] Hydrodynamic torque converter for a motor vehicle, characterized by that it comprises at least one device according to one of the preceding claims.

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