Torque transfer device with slip clutch having retaining tabs for receiving a disc spring using a bayonet connection

Abstract

The present invention relates to a torque transmission device (1) for a drive train of a motor vehicle, comprising an input part (2), a driving disc (3), and a slip clutch (4) mounted to act between the input part (2) and the driving disc (3), the slip clutch (4) being configured as a friction unit (6) biased by a disc spring (5), the disc spring (5) being housed and supported by a plurality of axially distributed retaining tabs (7) of the driving disc (3) or a counter disc (8) rigidly connected to the driving disc (3), the disc spring (5) being fixed to the retaining tabs (7) using a bayonet connection (9).

Description

[Technical Field]

[0001] The present invention relates to a torque transmission device for the drive train of a motor vehicle, such as a passenger car, truck, bus, or other commercial vehicle, comprising an input part, a driving disc, and a slip clutch integrated to act between the input part and the driving disc, the slip clutch being configured as a friction unit / friction clutch biased by a disc spring, the disc spring being housed and supported by a plurality of axially distributed / shaped retaining tabs on the driving disc or a counter disc rigidly connected to the driving disc. Thus, a torque transmission device is realized that is essentially configured as a slip clutch or has such a slip clutch. In addition to the slip clutch, a further damping device may in principle be present, constituting a torsional vibration damping device. [Background technology]

[0002] Torque transmission devices of the above type are already well known in the prior art. Such devices are disclosed, for example, in EP 2 511 554 A1. Devices in which molded tabs function to accommodate disc springs are already known. However, the proposed slip clutch is relatively laborious to assemble, since the tabs for accommodating the disc springs are usually only completed by axial extrusion or deformation when the disc springs are directly attached. In this case, the tabs are molded so that the disc springs remain biased. In this case, it is particularly difficult to mold all the tabs simultaneously and uniformly with the same (axial) dimensions. Additionally, this assembly method requires a press / press tool, which requires additional labor. Summary of the Invention [Problem to be solved by the invention]

[0003] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a torque transmission device with a slip clutch that is further simplified in manufacture and assembly. [Means for solving the problem]

[0004] This problem is solved according to the invention in that the disc spring is fixed / retained / secured to the retaining tab using a bayonet connection.

[0005] This bayonet connection allows all available retaining tabs to be precisely axially distributed and deformed to the required dimensions first, i.e., before assembling the disc springs, and only then are the disc springs connected to the retaining tabs in a single assembly step, thereby avoiding the need for unnecessarily complex deformation tools that previously required simultaneous assembly of the disc springs and deformation of the retaining tabs.

[0006] Further advantageous embodiments are set forth in the dependent claims and are explained in more detail below.

[0007] It is therefore also advantageous if the retaining tab is formed by the counter disc and passes axially through the drive disc, which results in a maximally compact design of the slip clutch in the axial direction. The counter disc is furthermore preferably realized as a directly deformed sheet metal (e.g., steel sheet).

[0008] Furthermore, it is advantageous if the retaining tabs are formed hook-shaped / hook-like (especially with circumferentially aligned hooks) for incorporating a bayonet connection, which allows the bayonet connection to be manufactured with maximum ease.

[0009] If the retaining tabs have circumferentially extending, open-sided receiving notches, each receiving a protrusion of the disk spring, no additional parts are required for the bayonet connection, while the components realizing the bayonet connection remain as simple as possible.

[0010] In addition, it is advantageous if the protrusion (of the disc spring) is formed on the radially outer or inner side of the disc spring, so that it can be appropriately positioned to create a maximum axially compact construction.

[0011] Furthermore, it is advantageous if the retaining force biasing the bayonet connection in the axial direction is generated directly by the disc spring (i.e., especially at the location where the disc spring is fixed non-rotatably to the retaining tab), so that the construction remains as simple as possible.

[0012] In connection with the formation of the receiving portions of the disk springs on the retaining tab side, it is also advantageous if each retaining tab has an axially extending connecting web toward its first circumferential side (receiving cutout) and an axially extending protuberance toward its second circumferential side (receiving cutout) facing away from the first circumferential side, so that the disk springs are supported by the connecting web and the protuberance in a manner that prevents them from rotating relative to each other, thereby providing the receiving cutouts with an effective and at the same time easy-to-manufacture receiving geometry.

[0013] In addition, to form the torque transmission device in a compact configuration that effectively acts as a torsional vibration damper device, it is advantageous if there is also present a hub provided for connection with the shaft, two hub flanges configured and fitted to the hub so that either the first hub flange or the second hub flange is connected to the hub so as to transmit torque depending on the direction of rotation of the hub relative to the hub flange, and a plurality of spring units indirectly supporting the first hub flange and the second hub flange relative to each other in the circumferential direction, and the drive disc is rotatably supported relative to the hub.

[0014] The configuration of the torque transmission device is further simplified if the drive disc is connected to the first and second hub flanges using friction devices. Preferably, the drive disc is connected to the first hub flange using a separate (first) friction device and to the second hub flange using a further (second) friction device.

[0015] Next, the present invention will be described in detail with reference to the drawings. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a longitudinal section of a torque transmission device according to the present invention in a preferred embodiment, in which the slip clutch formed according to the present invention can be clearly seen in the radially outer region. [Figure 2] 2 is a front view of the torque transmission device according to FIG. 1, specifically illustrating a plurality of spring units assembled between one of the two hub flanges and the intermediate flange of the torque transmission device; [Figure 3] 2 is a perspective detail view of the torque transmission device according to FIG. 1 cut longitudinally in the region of the slip clutch; [Figure 4] 1 is a schematic view of a hook-shaped retaining tab of a slip clutch as viewed from the radially outer side, specifically illustrating the accommodation of the protrusion of the disc spring in the accommodation notch of the retaining tab; [Figure 5] 5 is a front view of the disk spring assembled in FIGS. 1 to 4, which reveals a number of circumferentially distributed protrusions. FIG. [Figure 6] 2 is a perspective view of the counter disc assembled in FIG. 1 with a retaining tab molded therein; FIG. [Figure 7] FIG. 10 is a radially outward view of the retention tab. DETAILED DESCRIPTION OF THE INVENTION

[0017] The drawings are only of a schematic nature and are intended only to aid in the understanding of the invention. Identical elements are provided with identical reference numerals.

[0018] A torque transmission device 1 according to a preferred embodiment of the present invention will be described in detail below with reference to Figures 1 to 7. The torque transmission device 1, generally understood in Figures 1 and 2, is supported for rotation about a central rotation axis 23 during operation. The rotation axis directly defines the specifically used directional information: axial, radial, and circumferential. Therefore, the axial direction should be interpreted as the direction along the rotation axis 23, the radial direction as the direction perpendicular to the rotation axis 23, and the circumferential direction as the direction along a circumference concentrically surrounding the rotation axis 23.

[0019] During operation, the torque transmission device 1 is installed in the drive train of a motor vehicle in the usual manner. On the input side, the torque transmission device 1 has an input part 2, which may also be simply called a friction disc or formed as a friction disc. The input part 2 is made of a metal sheet (such as a steel sheet). The input part 2 is connected to a two-disk unit in the form of a driving disc 3 and a counter disc 8 fixed to the driving disc 3 via a slip clutch 4 formed according to the present invention. As can be seen clearly in FIG. 2, the input part 2 is axially fitted between a (first) disc area 24 of the driving disc 3 and a (second) disc area 25 of the counter disc 8. Friction elements such as friction linings 26a, 26b are installed axially between the respective disc areas 24, 25 and the input part 2.

[0020] The disc spring 5 serves to press the disc areas 24, 25 / friction linings 26a, 26b axially against the input part 2. The slip clutch 4 is therefore realized in the usual manner as a friction unit 6 / friction clutch, which opens briefly when a certain torque impulse is exceeded, allowing relative rotation between the input part 2 on the one hand and the connection between the driving disc 3 and the counter disc 8 on the other hand. As soon as the impact energy provided by the torque impulse has dissipated, the slip clutch 4 closes autonomously again, connecting the driving disc 3 and the counter disc 8 with the input part 2 in a non-rotatable manner.

[0021] 3 to 7, the inventive fixation of the disc spring 5 on both disc parts, the driving disc 3 and the counter disc 8, becomes clear. According to the invention, for its fixation the disc spring 5 is fastened to the counter disc 8 by means of a bayonet connection 9. The counter disc 8 receives the disc spring 5 in retaining tabs 7 that are distributed / shaped axially with respect to the second disc area 25. In this way, a plurality of, here 12, retaining tabs 7 are present on the counter disc 8 in a regularly distributed manner, as can be particularly well seen in FIG. 6.

[0022] Each retention tab 7 is formed hook-shaped / hook-like, with the formed hooks aligned in the circumferential direction. As a result, each retention tab 7 has a receiving cutout 10 that is open on one side in the circumferential direction, and the receiving cutouts 10 together define a hook shape (FIG. 7). Thus, the receiving cutout 10 extends circumferentially into the retention tab 7 from the circumferential side, essentially as an oblong hole. The receiving cutout 10 penetrates the retention tab 7 radially. The receiving cutout 10 is preferably made using a stamping process.

[0023] The receiving cutout 10 thus forms a receiving section for a protrusion 11 of the disc spring 5, which will be described in detail below. The receiving cutout 10 is limited toward the first circumferential side 14a by a connecting web 15 (of the retaining tab 7). The connecting web 15 directly supports the protrusion 11 of the disc spring 5 toward the first circumferential side 14a. Toward the second circumferential side 14b opposite the first circumferential side 14a, the receiving cutout 10 is open and is equipped with an axial ridge 16 / lug / lip. The ridge 16 supports the protrusion 11 of the disc spring 5 toward the second circumferential side 14b. Thus, each protrusion 11 of the disc spring 5 is fixed / supported between the ridge 16 and the connecting web 15 in the circumferential direction.

[0024] The formation of the protrusions 11 on the disc spring 5 and their reception in the reception cutouts 10 is particularly clear in Figures 3 to 5. According to Figure 5, the protrusions 11 are formed / attached to the radially inner side 13 of the disc spring 5. The radially outer side 12 of the disc spring 5 is free of protrusions / ridges in this embodiment and is therefore realized to have a circular shape. However, in further embodiments it is also possible in principle to attach the protrusions 11 to the radially outer side 12 instead.

[0025] 3 and 4 together, it is clear that in order for the disc spring 5 to be secured to the counter disc 8, i.e., using the bayonet connection 9, the protrusion 11 is first offset circumferentially relative to the retaining tab 7 and pressed axially against the axial side of the drive disc 3 / first disc area 24 opposite the second disc area 25. The disc spring 5 is then further compressed axially until the protrusion 11 is axially and circumferentially aligned with the receiving cutout 10 of the retaining tab 7. The disc spring 5 is then rotated relative to the counter disc 8 in order to slide the protrusion 11 into the receiving cutout 10. As soon as the respective projection 11 comes into contact with the connecting web 15 towards the first circumferential side surface 14a, the axial biasing force exerted from outside is again released on the disc spring 5, which brings its projection 11 into contact with the support surface 27 of the counter disc 8 axially opposite the second disc area 25. It can therefore be seen in Figure 4 that the projection 11 is in contact with the retaining tab 7 between the connecting web 15 and the ridge 16 due to the fastening of the bayonet connection 9.

[0026] With regard to further configurations of the torque transmission device 1, it can be seen that the torque transmission device 1 is formed as a torsional vibration damper device. The torque transmission device 1 further includes a centrally disposed hub 17, which serves to connect to an additional shaft of the drivetrain, such as a transmission input shaft. Two hub flanges 18, 19 are coupled to the hub 17. The hub flanges 18, 19 are rotatably accommodated relative to the hub 17 over a limited rotational angle range. The hub flanges 18, 19 are fitted to the hub 17 such that either the first hub flange 18 or the second hub flange 19 is connected to the hub 17 so as to transmit torque, depending on the rotational direction of the hub 17. When the hub 17 rotates in a first rotational direction, the hub 17 rotationally moves the first hub flange 18, which, in turn, is rotatable relative to the first hub flange 18 (at least over a limited rotational angle range) in a second rotational direction opposite the first rotational direction. When hub 17 rotates in the second rotational direction, hub 17 rotationally moves second hub flange 19, which in turn is rotatable (at least over a limited rotational angle range) relative to second hub flange 19 in a first rotational direction opposite the second rotational direction. Thus, depending on the pull / push drive of the drivetrain, hub 17 can rotate relative to either first hub flange 18 or second hub flange 19.

[0027] It can further be seen that multiple spring units 20a, 20b are operatively mounted circumferentially between the respective hub flanges 18, 19 and the intermediate flange 28. A first spring unit 20a (acting as a compression spring) is operatively mounted between the first hub flange 18 and the intermediate flange 28, which urge them toward / away from each other in the circumferential direction. A second spring unit 20b (acting as a compression spring) is operatively mounted between the first hub flange 19 and the intermediate flange 28, which urge them toward / away from each other in the circumferential direction.

[0028] The drive disc 3 more preferably has two split discs 29a, 29b, which are arranged on opposite axial sides of the hub flanges 18, 19 and rotatably supported on the hub 17. In this case, a first friction device 21 is operatively installed between the drive disc 3 / first split disc 29a and the first hub flange 18, while a second friction device 22 is operatively installed between the drive disc 3 / second split disc 29b and the hub flange 19. Each friction device 21, 22 rotatably connects each split disc 29a, 29b to each hub flange 18, 19.

[0029] In other words, the disc spring 5 is mounted according to the invention via a bayonet connection, for which purpose the disc spring 5 is provided with internally or externally placed tabs (projections 11), by means of which the disc spring 5 is screwed into the hook-shaped openings (receiving notches 10) of the counter disc 8.

[0030] Therefore, the damper (torque transmission device 1) is provided with a built-in torque limiter (slip clutch 4, for example arranged on the outside), in which the disc spring 5 is biased / retained via a bayonet lock / bayonet connection 9.

[0031] The disc spring 5 has a plurality of circumferentially distributed lugs on either the inner or outer diameter.

[0032] The counter disc 8 has tabs (retaining tabs 7) with hook-shaped openings distributed around its circumference according to the number of lugs of the disc spring 5.

[0033] The tabs of the counter disc 8 wedges axially through corresponding openings 30 in the driving disc 3 .

[0034] During assembly, the disc spring 5 is first placed on the driving disc 3 so that the tabs are positioned between the tabs of the counter disc 8. The disc spring 5 is then biased axially using a tool and rotated so that the tabs of the disc spring 5 are threaded into the hooks / hook-shaped openings of the counter disc 8. Finally, the biasing tool is removed and the disc spring 5 is biased axially to remain within the hooks of the counter disc 8.

[0035] More preferably, the lug (protrusion 16) acts as a safety device to prevent the disc spring 5 from loosening and coming off at the hook of the counter disc 8. [Explanation of symbols]

[0036] 1 Torque transmission device 2 Input section 3 Drive disc 4 slip clutch 5 disc spring 6 Friction Unit 7 Retention Tab 8 Counter Disc 9 Bayonet Connection 10. Storage notch 11 Protrusion 12 Outside 13 Inside 14a First circumferential side 14b Second circumferential side 15 Connecting Web 16 Ridge 17 Hub 18 First hub flange 19 Second hub flange 20a First spring unit 20b Second spring unit 21 First friction device 22 Second friction device 23 Rotation axis 24 First Disk Area 25 Secondary Disk Space 26a First friction lining 26b Second friction lining 27 Support surface 28 Intermediate flange 29a First partition disk 29b Second partition disk 30 Opening

Claims

1. A torque transmission device (1) for a drive train of a motor vehicle, comprising an input part (2), a driving disc (3), and a slip clutch (4) mounted to act between the input part (2) and the driving disc (3), the slip clutch (4) being configured as a friction unit (6) biased by a disc spring (5), the disc spring (5) being housed and supported by a plurality of axially distributed retaining tabs (7) of the driving disc (3) or a counter disc (8) rigidly connected to the driving disc (3). A torque transmission device (1), characterized in that said disc spring (5) is fixed to said retaining tab (7) using a bayonet connection (9).

2. 2. A torque transmission device (1) according to claim 1, characterized in that the retaining tab (7) is formed by the counter disc (8) and passes axially through the driving disc (3).

3. 3. A torque transmission device (1) according to claim 1 or 2, characterized in that the retaining tab (7) is formed in the shape of a hook.

4. 4. A torque transmission device (1) according to claim 1, wherein the retaining tabs (7) have circumferentially extending receiving notches (10) that are open on one side, and in each of the receiving notches (10) a protrusion (11) of the disk spring (5) is arranged.

5. 5. The torque transmission device (1) according to claim 4, characterized in that the protrusion (11) is formed on the radially outer side (12) or the radially inner side (13) of the disc spring (5).

6. 6. A torque transmission device (1) according to any one of claims 1 to 5, characterized in that the retaining force biasing the bayonet connection (9) in the axial direction is generated directly by the disc spring (5).

7. 7. The torque transmission device (1) according to claim 1, wherein each of the retaining tabs (7) has, towards a first circumferential side (14a), an axially extending connecting web (15) and, towards a second circumferential side (14b) facing opposite the first circumferential side (14a), an axial ridge (16), so that the disc spring (5) is supported by the connecting web (15) and the ridge (16) so as not to rotate relative to each other.

8. 8. The torque transmission device (1) according to claim 1, further comprising: a hub (17) for connection with a shaft; two hub flanges (18, 19) adapted to be fitted to the hub (17), wherein either the first hub flange (18) or the second hub flange (19) is connected to the hub (17) in a torque-transmitting manner depending on the direction of rotation of the hub (17) relative to the hub flanges (18, 19); and a plurality of spring units (20a, 20b) for indirectly supporting the first hub flange (18) and the second hub flange (19) relative to each other in the circumferential direction, wherein the driving disk (3) is rotatably supported relative to the hub (17).

9. 9. The torque transmission device (1) according to claim 8, characterized in that the driving disc (3) is connected to the first hub flange (18) and the second hub flange (19) using friction devices (21, 22).

Images