HOMOGENIZED SURFACE PRESSURE IN AN OVERLOAD CLUTCH

Abstract

An overload clutch in a drivetrain having a shaft-hub connection between an input part and an output part is disclosed. The overload clutch includes a press fit including a first contact surface and a second contact surface, wherein at least one of the first contact surface and the second contact surface is coated with a soft metal. For homogenizing a surface pressure of the first and second contact surfaces, an oversize allowance between components forming a shaft and a hub is selected prior to joining the shaft and the hub such that during the joining a yield point of the soft metal is reached or exceeded.

Claims

1-10. (canceled)

11. An overload clutch in a drivetrain having a shaft-hub connection between an input part and an output part, the overload clutch comprising: a press fit including a first contact surface and a second contact surface, wherein at least one of the first contact surface and the second contact surface is coated with a soft metal, and wherein, for homogenizing a surface pressure of the first and second contact surfaces, an oversize allowance between components forming a shaft and a hub is selected prior to joining the shaft and the hub such that during the joining a yield point of the soft metal is reached or exceeded.

12. The overload clutch of claim 11, wherein the overload clutch is provided as a press-press soldered connection.

13. The overload clutch of claim 11, wherein the shaft includes a secondary flywheel mass and an intermediate plate, the intermediate plate comprising one of the first contact surface or the second contact surface.

14. The overload clutch of claim 13, further comprising an equalizing element rotationally fixed to the hub and comprising the other one of the first contact surface or the second contact surface, wherein the equalizing element is supported indirectly against the secondary flywheel mass via the intermediate plate.

15. The overload clutch of claim 11, wherein the overload clutch is arranged in a dual-mass flywheel between the hub and a secondary flywheel mass forming the shaft.

16. A dual-mass flywheel, comprising: an input part formed from a primary flywheel mass; an output part formed from a secondary flywheel mass and a flange part; and an overload clutch arranged between the input part and the output part, the overload clutch including an equalizing element rotationally fixed to a hub, wherein the equalizing element has a first contact surface supported against a second contact surface of an intermediate plate forming a press fit therebetween.

17. The dual-mass flywheel of claim 16, wherein at least one of the first contact surface or the second contact surface is coated with a soft metal to form the press fit therebetween.

18. The dual-mass flywheel of claim 16, wherein a width of the equalizing element tapers continuously from the first contact surface to a radially opposite surface of the equalizing element, wherein the equalizing element is supported by a larger contact surface against the intermediate plate compared to a contact surface against the hub.

19. The dual-mass flywheel of claim 16, wherein the equalizing element is supported by a larger contact surface against the intermediate plate compared to a contact surface against the hub for homogenizing a surface pressure of the first and the second contact surfaces.

20. The dual-mass flywheel of claim 16, wherein an oversize allowance between the hub with associated equalizing element and the secondary flywheel mass with associated intermediate plate is selected prior to joining, in such a way that during the joining a yield point of a soft metal used for coating the first contact surface or the second contact surface is reached or exceeded for homogenizing a surface pressure of the first and the second contact surfaces.

21. The dual-mass flywheel of claim 16, wherein the intermediate plate encloses an end area of the secondary flywheel mass.

22. The dual-mass flywheel of claim 16, wherein the equalizing element is pressed into an aperture of the hub, and wherein in a pressing-in process, a profiling of the aperture cuts into an external contour of the equalizing element.

23. The dual-mass flywheel of claim 16, wherein in a limit position, the equalizing element is supported against the hub by way of a shoulder and is secured on an opposite side of the hub by calking.

24. The dual-mass flywheel of claim 16, wherein a sealing membrane is arranged between the equalizing element and the hub.

25. The dual-mass flywheel of claim 16, wherein the equalizing element is made from a soft metallic material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Further features and details of the present disclosure are revealed by the following description, in which an exemplary embodiment is described with reference to the drawings. Here the features mentioned in the claims and in the description may each be essential for the present disclosure either individually or in any combination. In the drawings:

[0019] FIG. 1 in a half-section shows a dual-mass flywheel with integral overload clutch; and

[0020] FIG. 2 shows an enlarged representation of details of the dual-mass flywheel according to FIG. 1.

[0021] FIG. 1 shows a sectional representation of a dual-mass flywheel 1, rotatable about an axis of rotation, that may also be referred to as a torsional-vibration damper. The dual-mass flywheel 1 that may also be described as a torque transmission device of very largely known type is intended, in particular, for a drivetrain of a motor vehicle not depicted in FIG. 1. Here an input part 2 forming a primary flywheel mass is preferably assigned to a crankshaft of an internal combustion engine, and an output part 3 is assigned via a friction clutch to a transmission. The input part 2 and output part 3 are formed as disk parts, which together form a circumferential annular space 4, into which the bow-springs 5 of a spring device 6 are inserted and guided. The output part 3 is rotatably supported by means of a rolling-contact bearing 7 and in relation to the input part 2 is rotatable to a limited degree in relation to the input part 2 against the action of the spring device 6. The output part 3 is formed from the secondary flywheel mass 8 and a flange part 9. An overload clutch 11 is integrated into the dual-mass flywheel 1 as impact protection. The overload clutch 11 constructed as a slipping clutch is arranged between a hub 12 designed as a flanged disk and the secondary flywheel mass 8. The hub 12 includes a centrifugal pendulum 10 and by means of drivers (not shown) engages externally in the spring device 6 for end-face support against the bow-springs 5. In relation to the dual-mass flywheel 1, the overload clutch 11 is therefore arranged between the input part 2 and output part 3. A press-press soldered connection 13 including two contact surfaces 16, 17 and forming a press fit 14 is provided as overload clutch 11, wherein at least one of the contact surfaces 16, 17 is coated with a soft metal or a solder.

[0022] FIG. 2 illustrates further details of the overload clutch 11 and the associated press-press soldered connection 13. The construction of the overload clutch 11 comprises an equalizing element 18 designed as a shoe, which is rotationally fixed to the hub 12. Via a contact surface 16 the equalizing element 18 is supported against a corresponding contact surface 17 of an intermediate plate 15, which together form a press fit 14. The intermediate plate 15 locally encloses an end area of the secondary flywheel mass 8. The equalizing element 18 having a trapezoidal cross-sectional profile tapers continuously from a width S in the area of the press fit 14 in the direction of the hub 12. Consequently, the equalizing element 18 is supported by a larger contact surface 16 against the intermediate plate 15 compared to the contact surface 24 against the hub 12. In order to achieve the press-press soldered connection 13, one of the contact surfaces 16 or 17 is coated with a soft metal as solder, before the components, the hub 12 with associated equalizing element 18 and the secondary flywheel mass 8 with associated intermediate plate 15, are joined together, there being an oversize allowance between the two components. For rotationally fixed arrangement of the equalizing element 18, a profiling 19, which in the joining process cuts into the external contour of the equalizing element 18 to form a positive interlock, is introduced in the aperture 20 of the hub 12. The equalizing element 18 is pressed into a central aperture 20 of the hub 12 until a shoulder 21 bears against the hub 12. This fitted position of the equalizing element 18 is secured by means of calking 22 on the opposite side to the shoulder 21. A sealing membrane 23, which extends in the direction of the output part 3, is furthermore fixed between the shoulder 21 of the equalizing element 18 and the hub 12.

[0023] In a first solution according to the present disclosure a homogenization of the surface pressure in the press fit 14 of the overload clutch 11 can be achieved by providing a defined oversize allowance between the shaft, that is to say the secondary flywheel mass 8 or its associated intermediate plate 15, and the hub 12. The oversize allowance is selected prior to joining in such a way that when joining the hub 12 and the shaft together a yield point of the soft metal or the solder that is used for coating at least one of the contact surfaces 16, 17 of the press-press soldered connection 13 is reached or exceeded.

[0024] In the second solution according to the present disclosure a homogenization of the surface pressure in the press fit 14 of the overload clutch 11 can be achieved by an equalizing element 18 designed as a shoe, which is supported against the surrounding construction, the intermediate plate 15 and the hub 12, via contact surfaces 16, 24 of different sizes. This design construction results in a reduced radial rigidity in the end zones of the contact surface 16 of the equalizing element 18.

LIST OF REFERENCE NUMERALS

[0025] 1 dual-mass flywheel

[0026] 2 input part

[0027] 3 output part

[0028] 4 annular space

[0029] 5 bow-spring

[0030] 6 spring device

[0031] 7 rolling-contact bearing

[0032] 8 secondary flywheel mass

[0033] 9 flange part

[0034] 10 centrifugal pendulum

[0035] 11 overload clutch

[0036] 12 hub

[0037] 13 press-press soldered connection

[0038] 14 press fit

[0039] 15 intermediate plate

[0040] 16 contact surface

[0041] 17 contact surface

[0042] 18 equalizing element

[0043] 19 profiling

[0044] 20 aperture

[0045] 21 shoulder

[0046] 22 calking

[0047] 23 sealing membrane

[0048] 24 contact surface

[0049] S width (equalizing element)