TORQUE TRANSMISSION ARRAY, TORSIONAL VIBRATION DAMPER AND CORRESPONDING ASSEMBLY

Description

[0001] The present invention relates to the field of torque transmission devices such as torsional dampers, particularly for motor vehicles.

[0002] The drive systems of motor vehicles comprise several components, including an engine and a gearbox, which are rotationally coupled to each other. This mechanical coupling is achieved, for example, by splines, with one component comprising a splined shaft and the other a complementary splined hub. Such a mechanical coupling is described, for example, in document WO2007045418 A1.

[0003] However, when the vehicle is in neutral and no torque is being transmitted by the drive chain, the play between the splines tends to produce noise due to impacts between them. This noise can travel into the passenger compartment and impair user comfort.

[0004] It is therefore necessary to find a solution to reduce or eliminate the noise produced at the level of the complementary splines of a shaft and a hub.

[0005] To this end, the present invention relates to a torque transmission device intended to be disposed between an engine and a gearbox of a motor vehicle, the torque transmission device comprising a splined hub intended to be fitted onto a complementary splined shaft of the gearbox in which the splined hub includes an annular groove at the level of its splines and in which the device also includes an elastic element intended to be disposed in the annular groove and configured to come into contact with the splines of the splined shaft of the gearbox.

[0006] The splined hub has teeth extending longitudinally relative to the axis of rotation of the transmission device. An annular groove is a groove formed by the hub that extends circumferentially around the axis of rotation of the device. The annular groove extends perpendicularly to the hub teeth. The annular groove extends through the teeth. Thus, in a direction parallel to the axis, the elastic element is inserted inside the annular groove.

[0007] According to another aspect of the present invention, the annular groove has a depth of between 1 and 10 mm.

[0008] According to another aspect of the present invention, the diameter of the splined shaft (3) is between 5 and 80 mm, or even between 15 and 65 mm, in particular between 20 and 45 mm.

[0009] According to another aspect of the present invention, the elastic element is made of elastomer.

[0010] According to another aspect of the present invention, the elastic element is an O-ring.

[0011] According to another aspect of the present invention, the elastic element is a grooved belt whose grooves are complementary to the grooves of the grooved shaft.

[0012] According to another aspect of the present invention, the elastic element (17, 47) is chosen from an O-ring, a grooved belt whose grooves are complementary to the grooves of the grooved shaft (3).

[0013] According to another aspect of the present invention, the elastic element is a radially corrugated metal ring.

[0014] According to another aspect of the present invention, the friction torque created by the elastic element is between 20 and 30 Nm.

[0015] The present invention also relates to a torsion damper comprising a torque transmission device as described above.

[0016] According to another aspect of the present invention, the torsional damper comprises a primary flywheel and a secondary flywheel forming a double damper flywheel.

[0017] The present invention also relates to a torque transmission assembly comprising: a first element comprising a splined shaft, a second element comprising a splined hub complementary to the splined shaft, in which one of the first or second element includes an annular groove at the level of its splines and in which the device also includes an elastic element intended to be disposed in the annular groove and configured to come into contact with the splines of the other of the first or second element.

[0018] Other features and advantages of the invention will become apparent from the following description, given by way of example and without limitation, with reference to the accompanying drawings in which: there figure 1 represents a schematic view along an axial section of a torsional damper, the figure 2 represents a cross-sectional view of an assembly between a hub and a transmission shaft comprising an elastic element according to a first embodiment, the figure 3 represents a perspective view of a hub according to the present invention, the figure 4a represents a cross-sectional view of an assembly between a hub and a transmission shaft comprising an elastic element according to a second embodiment, the figure 4b represents a perspective view of the elastic element according to the second embodiment, the figure 5a represents a cross-sectional view of an assembly between a hub and a transmission shaft comprising an elastic element according to a third embodiment, the figure 5b represents a perspective view of the elastic element according to the third embodiment, the figure 6 represents a view along an axial section of a clutch friction device.

[0019] In all figures, identical elements or elements performing the same function bear the same reference numbers.

[0020] The following are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment or that the features apply only to a single embodiment. Simple features from different embodiments can also be combined or interchanged to provide other embodiments.

[0021] In the following description, the terms "first," "second," "second," etc.—for example, "first part," "second part"—are used simply to index elements, naming and differentiating similar but not identical ones. This indexing does not imply any priority of one element over another, and such designations can easily be interchanged without departing from the scope of this description. Nor does this indexing imply any chronological order.

[0022] In the following description, the terms "axial", "radial" and "transverse" to define the orientation of the torsion damper elements refer to the rotation axis X of the torsion damper and define respectively a direction parallel to the rotation axis X, a plane including the rotation axis X and a plane perpendicular to the rotation axis X.

[0023] The present invention relates to a torque transmission device and in particular a torsional damper 1 of a motor vehicle as shown in the figure 1 intended to be coupled to a drive shaft 3, for example, from a gearbox (not shown). The drive shaft 3 has, for example, a diameter between 15 and 65 mm. The drive shaft 3 may correspond to the gearbox shaft of the motor vehicle. The torsional damper 1 is, for example, a double-mass flywheel and includes a primary element or primary flywheel 1'. The torsional damper 1 also includes a flange 7 configured to compress an elastic means such as a helical spring 9 during torque transmission. The flange 7 is, for example, fixed to a secondary element or secondary flywheel 1" and to a hub 5 by rivets 8. The hub 5 is intended to be coupled to the drive shaft 3. The secondary flywheel 1" is mounted to rotate relative to the primary element 1'.

[0024] Alternatively, the torsion damper 1 may be devoid of a secondary flywheel 1", the web 7 then being coupled in rotation only to the hub 5 intended to be coupled to the transmission shaft 3.

[0025] The helical spring 9 is, for example, placed in a housing 11 of the primary element 1' of the torsional damper 1. The housing 11 may also contain a channel 13 for retaining the helical spring 9. The primary element 1' and the secondary element 1" are mounted to rotate flexibly relative to each other about an axis of rotation X, for example via a bearing (not shown). The secondary element 1" may also include a pendulum device 11 configured to improve vibration damping. In an alternative configuration (not shown), the pendulum device may be mounted on the web 7.

[0026] The coupling between the hub 5 and the transmission shaft 3 is achieved by complementary splines 13 and 13' located respectively on the hub 5 and on the transmission shaft 3, the splines 13 of the hub 5 being fitted onto the splines 13' of the transmission shaft 3. The splines 13' of the transmission shaft 3 are more clearly visible on the figure 2 which represents a cross-sectional view of the hub 5 and the drive shaft 3.

[0027] There figure 3 represents a perspective view of the splines 13 of the hub 5. An annular groove or channel 15 is formed in the hub 5 at the splines 13 as shown in the figure 3 The annular groove 15 can be positioned within the splines 13 (the splines 13 are then on either side of the annular groove 15) as shown in the figure 3 but can also be provided at one end of the grooves 13. The annular groove 15 is configured to receive an elastic element and has a depth of between 1 and 10 mm, for example. The elastic element can be an O-ring 17 as shown in the figure 2 The O-ring 17 is configured to bear against the splines 13' of the drive shaft 3 to create a frictional torque with said splines 13', thus preventing collision between the splines 13 of the hub 5 and the splines 13' of the drive shaft 3 when no torque is transmitted between the hub 5 and the drive shaft 3, particularly when the vehicle is in neutral. The O-ring 17 can also be configured to create an elastic rotational torque, the O-ring being deformed to fit at least partially into the splines 13. The O-ring 17 is, for example, made of an elastomeric material. Furthermore, a strip can be placed between the O-ring 17 and the splines 13' of the drive shaft 3 to prevent rapid wear of the O-ring 17. The strip is, for example, made of a metallic material, particularly steel.The friction torque generated by the O-ring 17 is, for example, between 20 and 30 Nm

[0028] Alternatively, the elastic element can also be made by a corrugated metal ring 19 also configured to bear against the splines 13' of the transmission shaft 3 to create a friction couple as shown in the figures 4a et 4b which respectively represent the corrugated metal ring 19 mounted on the torsion damper and alone. The corrugated metal ring 19 is, for example, made of steel. The friction torque generated by the corrugated metal ring 19 is, for example, between 20 and 30 Nm

[0029] According to another embodiment shown on the figures 5a et 5b The elastic element can be made by means of a grooved elastic belt 21 whose grooves are substantially complementary to the grooves 13' of the hub 3. The grooved elastic belt 21 is for example made of elastomer material and is configured to create an elastic rotational torque to prevent a collision between the grooves 13 of the hub 5 and the grooves 13' of the transmission shaft 3 when no torque is transmitted between the hub 5 and the transmission shaft 3, for example when the motor vehicle is in neutral.

[0030] The present invention is not limited to a torsional damper but to any type of torque transmission device comprising a splined hub intended to be fitted onto a splined transmission shaft, such as, for example, a friction clutch device 30 as shown in the figure 6 .

[0031] The clutch friction device 30 includes a splined hub 31 for mounting on a splined transmission shaft 3. An annular disc 33 is fixed to the splined hub 31 and is configured to bear against an elastic means such as one or more helical springs 35 configured to filter vibrations and shocks transmitted by the clutch friction device 30. The helical spring 35 is positioned in a recess 37 of an element 39. The element 39 is rotatably mounted on the splined hub 31. The clutch friction device 30 also includes a support disc 41 fixed to the element 39 on its inner portion and configured to be positioned between friction linings 43 on its outer portion. The support disc 41 is rotatably linked to the linings 43.One of the friction linings 43 is configured to interact (on its face opposite the support disc 41) with a flywheel (not shown), and the other friction lining 43 is configured to interact (on its face opposite the support disc 41) with a pressure plate (not shown) of a clutch mechanism. Furthermore, the support disc 41 provides elasticity in the axial direction, which ensures smooth engagement and reduces jolts during the engagement and disengagement phases of the clutch friction device 30.

[0032] As in the case of the torsion damper 1 described previously, the splined hub 31 includes an annular groove 45 at its splines and the clutch friction device 30 includes an elastic element 47 intended to be positioned in the annular groove 45. The elastic element 47 can be similar to the elastic elements presented previously for the torsion damper 1.

[0033] Alternatively, for all the embodiments presented above, the annular groove can be provided at the splines 13' of the transmission shaft 5, the elastic element then being configured to be positioned in said annular groove and to come into contact with the splines 13 of the hub 5 or 31.

[0034] Furthermore, the present invention also relates to an assembly comprising a first element including a splined shaft 3 and a second element including a splined hub 5, 31 complementary to the splined shaft 3, the first and second elements corresponding for example to the different embodiments described above.

[0035] Thus, the use of an annular groove formed at the splines of an assembly comprising a splined shaft and a complementary splined hub and an elastic element disposed in the annular groove and configured to come into contact with the splines of the complementary element makes it possible to limit the shocks between the different splines when no torque is transmitted by the assembly and thus reduce the noise produced by these shocks.

Claims

1. Torque transmission device (1, 30) intended to be arranged between an engine and a gearbox of a motor vehicle, the torque transmission device (5, 30) comprising a splined hub (5, 31) intended to be fitted onto a complementary splined shaft (3) of the gearbox characterized in that the splined hub (5, 31) comprises an annular groove (15, 45) at the level of its splines (13) and in that the device also comprises an elastic element (17, 19, 21, 47) intended to be arranged in the annular groove (15, 45) and configured to come into contact with the splines of the splined shaft (3) of the gearbox.

2. Device (1, 30) according to claim 1 in which the annular groove (15, 45) has a depth between 1 and 10 mm.

3. Device (1, 30) according to claim 1 or 2 in which the diameter of the splined shaft (3) is between 5 and 80 mm, or even between 15 and 65 mm, particularly between 20 and 45 mm.

4. Device (1, 30) according to any one of the preceding claims in which the elastic element (17, 21, 47) is made of elastomer.

5. Device (1, 30) according to any one of the preceding claims in which the elastic element (17, 47) is chosen from an 0-ring, a splined belt whose splines are complementary to the splines of the splined shaft (3).

6. Device (1, 30) according to any one of claims 1 to 3 in which the elastic element (19, 47) is a radially undulated metal ring.

7. Device (1, 30) according to any one of the preceding claims in which the friction torque created by the elastic element (17, 19, 21, 47) is between 20 and 30 Nm.

8. Torsion damper (1) comprising a torque transmission device according to any one of the preceding claims.

9. Torsion damper (1) according to the preceding claim comprising a primary flywheel (1') and a secondary flywheel (1") forming a dual mass flywheel.

10. Torque transmission assembly comprising: - a first element comprising a splined shaft (3), - a second element comprising a splined hub (5, 31) complementary to the splined shaft (3), characterized in that one of the first or second element comprises an annular groove (15, 45) at the level of its splines and in that the device also comprises an elastic element (17, 19, 21, 47) intended to be arranged in the annular groove (15, 45) and configured to come into contact with the splines of the other of the first or second element.