EP2795148A1

EP2795148A1 - Friction clutch

Info

Publication number: EP2795148A1
Application number: EP12816444.9A
Authority: EP
Inventors: Marc Finkenzeller; Eric Lambs
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2011-12-22
Filing date: 2012-12-05
Publication date: 2014-10-29
Also published as: WO2013091598A1; DE112012005409A5; CN104040203A; DE102012222269A1; CN104040203B

Abstract

The invention relates to a friction clutch for a drive train of a motor vehicle, having a contact plate, which is connected to a housing in a non-rotatable manner yet with limited axial movement, a disc spring, which is effective between the housing and the contact plate and loads the contact plate in the axial direction in order to clamp a clutch disc between the contact plate and a counter-plate, and a damping arrangement having at least one friction element that has a damping effect on at least axial vibrations of the contact plate and/or of the disc spring, wherein the at least one friction element has a contact region that is in operative engagement with an axial face of the disc spring and/or with an outer edge of the contact plate. The hysteresis of the clutch according to the invention can be increased by relatively simple structural measures and the torque fluctuation can thereby be reduced.

Description

friction clutch

The invention relates to a friction clutch, which can be used in particular as a starting clutch in a drive train of a motor vehicle and with the aid of a torque from an input shaft, such as a crankshaft of an engine, on an output shaft, such as an input shaft of a transmission, can be forwarded.

In a starting clutch, as known for example from DE 197 46 281 A1, a torque generated by a motor vehicle engine can be transmitted via a flywheel rotatable about an axis of rotation. With the flywheel, a pressure plate for forwarding the torque is connected, which can then transmit the torque via a friction lining frictionally to a clutch disc.

Due to axial vibrations in the crankshaft, there may be a relative movement between the clutch and a release bearing, especially in clutches with a path-controlled wear adjustment, whereby the contact pressure of the clutch and thus the transmittable torque can fluctuate. Such torque fluctuations occur in particular in the slip phase of the clutch - ie, especially during the starting process - and generate chatter noise, namely the so-called Anfahrrattern.

There is therefore a need to reduce such Rattergeräusche, especially in clutches with path-based wear adjustment, while increasing the torque transmission and the starting comfort when closing the clutch. An object of the invention is therefore to provide a friction clutch for a drive train of a vehicle, with the aid of an improved torque transmission when closing the clutch is enabled and less Anfahrrattern occurs, without significantly reducing Anfahrkomfort.

The object is achieved by a friction clutch for a drive train of a motor vehicle having the features of claim 1. Preferred embodiments of the invention are specified in the dependent claims.

CONFIRMATION COPY According to the invention, a friction clutch is provided for a drive train of a motor vehicle, with a pressure plate which is non-rotatably, but axially limited displaceable connected to a clutch housing, a plate spring, which is effective between the housing and the pressure plate and the pressure plate acted upon in the axial direction to a Clamping disc between the pressure plate and a counter-plate clamped, and a damping device with at least one friction element which acts damping on at least axial vibrations of the pressure plate and / or the plate spring, wherein the at least one friction element has a contact region with one axial side of the plate spring and / or is operatively engaged with an outer edge of the pressure plate.

The friction clutch according to the invention is in particular as a starting clutch for

Forwarding a torque from a crankshaft of an engine of the motor vehicle formed on an input shaft of a transmission of the motor vehicle. By the at least one friction element of the damping device, the hysteresis of the clutch, in particular the Ausrückkrafthysterese increased and thus the Anfahrratterntern be reduced or suppressed. Preferably, the damping device has a plurality of the friction elements and these can be distributed substantially uniformly about an axis of rotation of the clutch, in order to distribute their effect on the hysteresis of the clutch also largely uniform.

In a preferred embodiment of the invention, the at least one friction element is located in the contact region either with axial prestress on the axial side of the plate spring and / or with radial prestress on the outer edge of the pressure plate. By a resilient bias of the friction elements in the axial direction on the axial side of the plate spring or in the radial direction on the outer edge of the pressure plate, the friction hysteresis of the damping device and thus the clutch can be increased in a simple manner.

In a preferred embodiment of the invention, the at least one friction element of the damping device is axially fixed relative to the clutch housing or on the clutch housing. Typically, the plate spring acts on the pressure plate in a radially outer region of the plate spring and the plate spring is connected in a radially inner region lying by means of a pivot bearing with the housing. In a particularly preferred embodiment of the invention, the at least one friction element is fixed to the pivot bearing. In this case, the contact region of the at least one friction element can be operatively frictionally engaged with an axial side of the plate spring facing the clutch disk. Alternatively or additionally, the contact area of the mini- at least one frictional friction rubbing operatively engaged with one of the clutch disc facing away from axial side of the plate spring.

In a preferred embodiment of the invention, the at least one friction element of the damping device, in particular in the contact region, bow-shaped or wave-shaped. Likewise, it is possible to attach the said friction elements to the plate spring, preferably to the leaves or tongues of the plate spring, so that the plate spring is formed in several layers. Furthermore, the at least one friction element or each friction element in the contact region may have a treated surface, the surface preferably being treated by coating (for example with a polyamide) and / or by roughening (for example by blasting) to increase the coefficient of friction. According to the invention, therefore, one or more friction elements are used which have a friction-increasing coating and / or a roughened surface. Alternatively or additionally, the use of lubricants can be dispensed with in the contact area.

In a preferred embodiment of the invention, the at least one friction elements of the damping device is formed on an annular base body, wherein the annular base body is preferably fixedly connected to the coupling housing or connected.

By relatively simple design measures, the hysteresis of the coupling system according to the invention, in particular the Ausrückkrafthysterese be increased and by this targeted increase in the hysteresis of the coupling system (ie, the higher damping), the torque fluctuations can be reduced and thus the Rattergeräusche be eliminated. The hysteresis can basically be increased by increasing the coefficient of friction at the contact points pressure plate-plate spring, plate spring wire ring, plate spring centering pin / centering plate, disc spring release bearing.

The invention will now be described by way of example with reference to the accompanying drawings with reference to preferred embodiments, wherein the features shown below, both individually and in combination may represent an aspect of the invention. Show it:

Figure 1: a schematic sectional view of a portion of a friction clutch

according to a first embodiment of the invention with biased friction between pressure plate and lid, Figure 2 is a sectional view of the friction clutch in Figure 1, a schematic sectional view of a portion of a friction clutch according to a second embodiment of the invention with biased friction between housing cover and disc spring, a schematic sectional view of a portion of a friction clutch according to a third embodiment of the invention with one of the support spring formed friction member in frictional contact with the plate spring tongues, a detailed sectional view of a portion of a plate spring in a friction clutch according to a fourth embodiment of the invention with a friction element arranged on a Belleville washer, a schematic sectional view of a portion of a friction clutch according to a fifth embodiment of the invention with a prestressed between Cover and wire ring inserted friction element, a schematic sectional view of a portion of a friction clutch according to a sixth embodiment of the invention with a friction element mounted on the pressure plate and a schematic sectional view of a portion of a plate spring for a friction clutch according to a seventh embodiment of the invention.

Referring first to Figures 1 and 2, a friction clutch 1 according to a first embodiment is shown in a partial view. The friction clutch 1, which is designed in particular for use as a starting clutch in a drive train of a motor vehicle, has a pressure plate 2 which is non-rotatably, but limitedly displaceable in the axial direction A connected to a clutch housing 3. The part 1 shown in Figure 1 of the housing 3 in this embodiment is a housing cover 4. Furthermore, the clutch 1, a plate spring 5, which is effective as a contact pressure between the pressure plate 2 and the housing 3 and the pressure plate 2 in the axial direction A (ie , in Figures 1 and 2 down) applied to a clutch disc S (shown purely schematically) between the pressure plate 2 and a counter plate (not shown) pinch. In this case, the plate spring 5 presses in its radially outer region 6 against a provided on the pressure plate adjusting ring V, which lies opposite a spacer bolt B in the housing cover 4. The radially outer portion 6 of the plate spring 5 is annular and the individual leaves or tongues Z of the plate spring 5 extend from the annular outer portion 6 radially inwardly.

The clutch 1 further comprises a damping device 7 with a plurality of friction elements 8, which are distributed substantially uniformly around an outer circumference of the pressure plate 2. Each friction element 8 in this embodiment is bow-shaped (preferably made of sheet metal) and has a contact region 9, which is frictionally engaged with an elastic bias in the radial direction R (ie, radially inward) with an outer edge 10 of the pressure plate 2. The opposite end 11 of the friction element or the friction yoke 8 is axially fixed to the cover 4 and thus relative to the housing 3. Upon actuation of the clutch 1, the plate spring 5 is moved in the central region 12 in the axial direction A, which in turn causes an axial movement of the pressure plate 2 by means of a pivot bearing 13 with a disc spring pin 14 and a wire ring 15. By their frictional contact with the outer edge 9 of the pressure plate 2, the friction elements 8 increase the hysteresis of the clutch 1 and thus have a damping effect on axial vibrations of the pressure plate 2 and / or the plate spring 5 a. As a modification of this embodiment, the friction elements 8 could be fixed to the outer edge 10 of the pressure plate 2, so that the ends 11 of the friction bracket 8 then rubbing engaged with the cover 4 and thus could represent the contact area.

Referring now to Figure 3, a friction clutch 1 according to a second embodiment is shown schematically in partial view. The general structure of the clutch 1 in this example corresponds to that of Figures 1 and 2, so that the clutch 1 again has a pressure plate 2, the rotationally fixed, but limited displacement in the axial direction A with a clutch housing 3 and housing cover 4 is connected. Further, the clutch 1, a plate spring 5, which is effective as a contact pressure between the pressure plate 2 and the housing 3 and the pressure plate 2 in the axial direction A (down) applied to a clutch plate S between the pressure plate 2 and a counter plate (not to pinch). The clutch 1 further comprises a damping device 7 with a plurality of friction elements 8, which are distributed substantially uniformly around a radial circumference of the plate spring 5. Each friction element 8 in this example is bow-shaped (preferably made of sheet metal) and has a contact region 9, which with elastic bias in the axial Direction A (down) with one of the clutch disc S remote axial side 16 of the plate spring 5 is frictionally engaged, in the radially outer region 6 of the plate spring 5, in which it acts on the pressure plate 2. The opposite end 11 of the friction element or the friction yoke 6 is axially fixed to the cover 4 and thus relative to the housing 3. Upon actuation of the clutch 1, the diaphragm spring 4 is moved in its central region 12 in the axial direction A, which in turn causes an axial movement of the pressure plate 2 by means of a pivot bearing 13 with a wire ring 15. By their frictional contact with the side 16 of the plate spring 5, the friction elements 8 increase the hysteresis of the clutch 1 and thus have a damping effect on axial vibrations of the pressure plate 2 and the plate spring 5 a.

Referring now to Fig. 4, a part of a friction clutch 1 according to a third embodiment is shown. The general structure of the coupling 1 in this example corresponds to that of Figure 3. The friction elements 8 of the damping device 7 are again bow-shaped, preferably made of sheet metal, but are arranged in this case on the pivot bearing 13 of the plate spring 5 on the housing 3. In particular, the friction elements or friction yokes 8 on the disc spring pin 14 are axially fixed again relative to the clutch housing 3. The contact region 9 of each friction yoke 8 is operatively frictionally engaged with elastic bias in the axial direction A (upward) in engagement with a side 17 of the diaphragm spring 5 facing the clutch disc S, in contact with the blades or tongues Z of the diaphragm spring 5 in FIG Area of the pivot bearing 13, which is radially further inside than the radially outer portion 9 of the loading of the plate spring 4. The friction elements 8 increase the hysteresis of the clutch 1 by its frictional contact with the axial side 17 of the plate spring 5 and thus have a damping effect on axial vibrations of the pressure plate 2 and the plate spring 5 a.

With reference to FIG. 5, a completely different type of friction element 8 of the damping device 7 for a friction clutch 1 according to a fourth exemplary embodiment is shown. In this example, the friction elements 8 are similar to how shaft seals (sealing lips) constructed and arranged rubbing against the disc spring pin 14. The friction element 8 shown in Figure 5 surrounds the edges of a hole 18 through the plate spring 5 and thus extends on both axial sides 16, 17 of the plate spring 5. Further, the friction element 8 defines a central channel for receiving the bolt 14 and an inner contact surface 19th of the channel is undulating to create a desired friction with the bolt 14. The friction elements 8 in this embodiment increase the hysteresis of the clutch 1 by its frictional contact with the sides 16, 17 of the plate spring 5 and with the Belleville washer bolts 14 and NEN thus damping effect on axial vibrations of the pressure plate 2 and the plate spring 5.

Referring to FIG. 6, a part of a friction clutch 1 according to a fifth embodiment is shown. In this example, the friction element 8 is inserted between the cover 4 and the wire ring 15 and thus axially fixed relative to the housing 3 on the pivot bearing 13. The contact region 9 of each friction element 8 is frictionally engaged in the axial direction A (down) with the side 16 of the plate spring 5 and thus generates a friction in the annular radially outer region 6, which increases the hysteresis of the clutch 1 and damping on Axial vibrations of the pressure plate 2 and the plate spring 5 acts.

In Figure 7, a further embodiment is shown, in which the friction element 8 is formed as a Abhubbügel, which is fixed at one end 11 on the pressure plate 2. The other end thus forms the contact region 9, which is frictionally engaged with the side 17 of the plate spring 5. The disadvantage here, however, is the Relativweg between the pressure plate 2 and the plate spring 5 due to an adjustment of the clutch 1 in the event of wear, resulting in an undesirable additional bias. In this example, the friction yoke 8 is not fixed axially with respect to the housing 3.

Referring now to Figure 8, the friction element 8 is attached to the plate spring 5, in particular at its radially outer portion 6, so that the plate spring 5 is formed multi-layer and generates a desired friction with the adjusting ring V upon actuation of the clutch 1. Alternatively or additionally, friction elements 8 can be attached to the blades or tongues Z of the disc spring 5, so that an increase in the hysteresis of the clutch 1 is achieved in that the plate spring 5 is constructed as a spring assembly. This can occur between contact surfaces of the disc springs friction. Further, by increasing the diameter of the centering bolts or the width of the centering tab, the friction between the disk spring and centering element can be increased. In addition, the number of centering windows can be increased, which entails an increase in the hysteresis.

By the possibilities listed above, the friction in the clutch system 1 and thus the hysteresis can be increased. Due to the increased hysteresis in the coupling system 1, the formation of chattering noise during startup should be prevented. The Application is provided in particular for couplings with weggesteuerter wear adjustment.

LIST OF REFERENCES

1 friction clutch

2 pressure plate

3 coupling housing

4 housing cover

5 plate spring

6 Radial outer area of the diaphragm spring

7 damping device

8 friction element or friction bracket

9 Contact area of the friction element

10 outer edge of the pressure plate

1 1 End of the friction element

12 Central area of the diaphragm spring

13 pivot bearing

14 spring washers

15 wire ring

16 of the clutch disc facing away from the plate spring

17 of the clutch disc facing side of the plate spring

18 holes

19 contact surface

S clutch disc

A axial direction

R radial direction

V adjusting ring

B Spacing bolts

Z leaves or tongues of the diaphragm spring

Claims

claims

1. friction clutch (1) for a drive train of a motor vehicle, with

a pressure plate (2) which is non-rotatably, but axially limited displaceable connected to a coupling housing (3),

a plate spring (5) between the housing (3) and the pressure plate (2) is effective and the pressure plate (2) in the axial direction (A) acted to clamp a clutch disc between the pressure plate (2) and a counter-plate, and

a damping device (7) having at least one friction element (8) which acts in a damping manner on axial vibrations of the pressure plate (2) and / or the plate spring (5), wherein the at least one friction element (8) has a contact region (9) with a axial side (16, 17) of the plate spring (5) and / or an outer edge (10) of the pressure plate (2) is operatively engaged.

Second friction clutch (1) according to claim 1, wherein the at least one friction element (8) in the contact region (9) either with axial bias on the axial side (16, 17) of the plate spring (5) and / or with radial bias on the outer edge ( 10) of the pressure plate (2) is applied.

Third friction clutch (1) according to claim 1 or 2, wherein the at least one friction element (8) of the damping device (7) relative to the clutch housing (3) is axially fixed.

4. friction clutch (1) according to claim 3, wherein the plate spring (5) in its radially outer region (6) the pressure plate (2) acted upon and in a radially further inside region by means of a pivot bearing (13) with the housing (3). is connected, wherein the at least one friction element (8) is preferably fixed to the pivot bearing (13).

5. friction clutch (1) according to one of claims 1 to 4, wherein the at least one friction element (8) of the damping device (7) in the contact region (9) is bow-shaped or wavy.

6. friction clutch (1) according to one of claims 1 to 5, wherein the at least one friction element (8) in the contact region (9) has a treated surface, preferably treated by coating and / or by roughening.

7. Friction clutch according to one of claims 1 to 6, wherein the contact region (9) of the at least one friction element (8) facing away from the clutch disc (S) a- xialen side (16) of the plate spring (5) operatively frictionally engaged.

8. friction clutch (1) according to one of claims 1 to 7, wherein the contact region (9) of the at least one friction element (8) with one of the clutch disc (S) facing the axial side (17) of the plate spring (5) operatively frictionally engaged , Preferably in a region which is located radially further inward than the radially outer region (6) in which the plate spring (5) acts on the pressure plate (2).

9. friction clutch according to one of claims 1 to 8, wherein the damping device (7) has a plurality of friction elements (8) acting on at least axial vibrations of the pressure plate (2) and / or the plate spring (5) damping.

10. Friction clutch according to one of claims 1 to 9, wherein the at least one friction elements (8) of the damping device (7) is formed on an annular base body, wherein the annular base body is preferably axially fixed to the housing (3) connected or connectable.