FRICTION CLUTCH

Abstract

A friction clutch for a drivetrain of a motor vehicle includes an engine-side input part, a transmission-side output part, friction elements, an engine-side actuating device, and a transmission-side actuating device. The engine-side input part is disposed rotatably around an axis of rotation. The friction elements are arranged for frictionally engaging the engine-side input part to the transmission-side output part. The engine-side actuating device is arranged between the engine-side input part and the friction elements. The transmission-side actuating device is arranged between the transmission-side output part and the friction elements. At least one of the engine-side actuating device or the transmission-side actuating device is a centrifugal force controlled actuating device arranged to clamp the friction elements against one another.

Claims

1-10. (canceled)

11. A friction clutch for a drivetrain of a motor vehicle comprising: an engine-side input part disposed rotatably around an axis of rotation; a transmission-side output part; friction elements arranged for frictionally engaging the engine-side input part to the transmission-side output part; an engine-side actuating device arranged between the engine-side input part and the friction elements; and, a transmission-side actuating device arranged between the transmission-side output part and the friction elements, wherein: at least one of the engine-side actuating device or the transmission-side actuating device is a centrifugal force controlled actuating device arranged to clamp the friction elements against one another.

12. The friction clutch of claim 11, wherein the engine-side actuating device and the transmission-side actuating device are connected in parallel.

13. The friction clutch of claim 11, wherein the engine-side actuating device and the transmission-side actuating device are connected in series.

14. The friction clutch of claim 11, further comprising a release mechanism, actuatable by a driver or automatically, to release the friction clutch.

15. The friction clutch of claim 11, wherein the friction elements comprise a plate pack with alternately stacked friction plates and steel plates that are axially pre-stressed by the engine-side actuating device or the transmission-side actuating device, depending on the centrifugal force.

16. The friction clutch of claim 15 further comprising: an axially fixed base plate; and, a cup-shaped load transfer plate, axially movable and rotationally coupled relative to the axially fixed base plate, for axially pre-stressing the friction plates and the steel plates.

17. The friction clutch of claim 15 further comprising: an axially fixed base plate; and, a plate carrier, axially movable and rotationally coupled relative to the axially fixed base plate, for axially pre-stressing the friction plates and the steel plates.

18. The friction clutch of claim 17, wherein the engine-side actuation device or the transmission-side actuation device comprises: an axially fixed plate piece; an axially movable plate piece; and, a radially movable centrifugal mass disposed axially between the axially fixed plate piece and the axially movable plate piece, wherein: the axially fixed plate piece and the axially movable plate piece are arranged to form a ramp device; and, the axially movable plate piece acts on the plate carrier axially against the axially fixed base plate.

19. The friction clutch of claim 18 further comprising a resilient element, wherein: the axially movable plate piece acts on the plate carrier against the resilient element; and, the resilient element comprises a spring element or a leaf spring.

20. The friction clutch of claim 18 further comprising an output-side hub piece, wherein the axially fixed plate piece and the axially movable plate piece are rotatable relative to the output-side hub piece.

21. The friction clutch of claim 17, wherein: the engine-side actuation device comprises: an engine-side axially fixed plate piece; an engine-side axially movable plate piece arranged with the engine-side axially fixed plate piece to form a ramp device; and, an engine-side radially movable centrifugal mass disposed axially between the engine-side axially fixed plate piece and the engine-side axially movable plate piece; the transmission-side actuation device comprises: a transmission-side axially fixed plate piece; a transmission-side axially movable plate piece arranged with the transmission-side axially fixed plate piece to form a ramp device; and, a transmission-side radially movable centrifugal mass disposed axially between the transmission-side axially fixed plate piece and the transmission-side axially movable plate piece; and, the engine-side axially movable plate piece acts on the plate pack through the transmission-side axially movable plate piece.

22. A friction clutch comprising: an input-side arranged for driving connection with an engine; an output-side arranged for driving connection with a transmission; a clutch pack comprising a plurality of friction elements arranged to frictionally connect the input-side to the output-side; an input-side centrifugal actuator arranged to clamp the clutch pack at a first engine speed; and, an output-side centrifugal actuator arranged to clamp the clutch pack at a first transmission speed.

23. The friction clutch of claim 22 wherein the input-side centrifugal actuator or the output-side centrifugal actuator comprises: a first plate; a second plate arranged with the first plate to form a ramp element; and, a radially displaceable centrifugal mass disposed axially between the first plate and the second plate.

24. The friction clutch of claim 22 further comprising a release mechanism arranged to overcome the input-side centrifugal actuator, the output-side centrifugal actuator, or both the input-side centrifugal actuator and the output-side centrifugal actuator to unclamp the clutch pack.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The disclosure will be explained in further detail on the basis of the exemplary embodiment depicted in FIGS. 1 through 5. The figures show the following:

[0016] FIG. 1 is a sectional view through a friction clutch having two parallel actuating devices and a release device,

[0017] FIG. 2 is the friction clutch of FIG. 1 in 3D sectional view,

[0018] FIG. 3 is a partial section through a friction clutch modified in comparison to the friction clutches of FIGS. 1 and 2, with the actuating devices arranged in parallel,

[0019] FIG. 4 is a section through a friction clutch having two parallel actuating devices without a release device and

[0020] FIG. 5 is a diagram of the operating principle of the friction clutch of FIGS. 1 through 4.

DETAILED DESCRIPTION

[0021] FIGS. 1 and 2 show, in sectional view and in 3D sectional depiction, an overview of the friction clutch 1 disposed rotatingly around the axis of rotation d, with the input part 2 and the output part 3. The input part 2 has the input-side plate carrier 5, supported on the hub piece 4 so that it is axially fixed and rotatable by means of the roller bearing 6 and thrust bearing; the plate carrier 5 is rotationally driven radially outside by means of the ring gear 7, for example by a primary drive of an engine. The plate carrier 5, as plate piece 45, with the plate piece 8 and the centrifugal masses 9 distributed around the circumference, forms the ramp device 10, which thereby forms the engine-side actuating device 11. By means of the stampings 12, the plate carrier 5 guides the centrifugal masses 9, fixed in the circumferential direction and radially movably. The plate piece 8 has ramps 13 running radially outside axially toward the radial extension of the plate carrier 5 which forms a plate extension or plate part, so that under the influence of the centrifugal force of the friction clutch 1 rotating about the axis of rotation d, the centrifugal masses are moved radially outward, and the plate piece 8 is moved axially while being braced axially on the plate carrier 5, which is braced axially on the hub piece 4. This results in an axial rise between a specified speed of rotation, for example the idle speed of the engine, and a limiting speed at which the centrifugal masses 9 are displaced radially by a maximum amount, for example coming to rest radially outside on the axial extension 14 of the plate carrier 5 which receives the ring gear 7. The rise is transmitted to the thrust ring 16, rotationally uncoupled, by means of the roller bearing 15.

[0022] The plate carrier 5 receives the friction elements 18 in the form of friction plates 17, rotationally fixed and axially movable to a limited extent. These, stacked alternating with the output-side friction elements 20 in the form of steel plates 19, form the plate pack 21.

[0023] The output part 3 is constructed as follows: The steel plates 19 are received radially inside on the plate carrier 22, for example hooked in, non-rotating and axially movable to a limited extent. The plate pack 21 is supported axially on the output-side base plate 24, and is acted on axially by the cup-shaped load transfer plate 23 connected to the plate carrier 22.

[0024] The base plate 24 receives the hub plate 26 firmly at an axial distance by means of the bolts 25 distributed around the circumference. The hub plate 26 is received firmly on the hub piece 4 by means of the thrust ring 27, and forms a rotationally locked connection with the transmission input shaft 28. The plate piece 29 is connected firmly to the hub plate 26 at an axial distance by means of the bolts 30 distributed around the circumference.

[0025] The plate carrier 22 is connected non-rotatingly and axially movably to the hub plate 26 by means of the leaf springs 31 distributed around the circumference, so that when a frictional engagement of the friction elements 18, 20 is formed, a torque introduced into the input part 2 is transmitted via the plate carrier 22 and the cup-shaped load transfer plate 23 to the hub plate 26, and thus to the transmission input shaft 28. The plate piece 32 is axially pre-stressed relative to the cup-shaped load transfer plate 23 by means of the bolts 33 distributed around the circumference and the spring elements 34in this case helical compression springs. The axially fixed plate piece 29 and the plate piece 32, which is movable axially contrary to the effect of the spring elements 34, receive axially between them the centrifugal masses 35, which are distributed around the circumference and are radially movable. Radially outside, the plate piece 32 has the ramps 36 which run toward the plate piece 29. The plate piece 29 has stampings 40, which guide the centrifugal masses 35 fixedly in the circumferential direction and radially movably. These components form the ramp device 37, and the actuating device 38 on the transmission side. When the centrifugal force increases due to the speed of rotation, the centrifugal masses 35 are displaced radially outward, so that when the spring elements 34 and the leaf springs 31 are pre-stressed the cup-shaped load transfer plate 23 is moved axially and the frictional engagement of the friction elements 18, 20 is produced.

[0026] The coupling of the input-side actuating device 11 to the cup-shaped load transfer plate 23 occurs by means of the actuating device 38. The bolts 39 on the axially movable plate piece 32, distributed around the circumference and extending in the direction of the thrust ring 16, are provided for this purpose. When the actuating device 11 is actuated on the input side, the plate piece 8 moves the thrust ring 16 by means of the roller bearing 15, and thus the bolts 39. This moves the plate piece 32 axially, and the cup-shaped load transfer plate 23 acts on the plate pack 21.

[0027] During a driving-off process, in this way the actuating device 11 takes over pressing the plate pack against the base plate 24. As soon as the transmission input shaft 28 has reached a sufficient speed, the centrifugal masses 35 are accelerated radially outward, so that the contact pressure is intensified. A limitation of the contact pressure can be achieved through appropriate design of the spring elements 34, which give way under a specified overpressure. If the engine speed is reduced while the vehicle is moving, the pressing of the plate piece 8 decreases; however, the pressing and pre-stressing of the plate pack 21 is maintained as a result of the axial movement of the plate piece 32 and pre-stressing of the cup-shaped load transfer plate 23, until the motor vehicle has slowed below an appropriate velocity corresponding to a specified rotational speed of the transmission input shaft 28.

[0028] In addition to the actuating devices 11, 38, which press the friction clutch 1 into engagement depending on centrifugal force, the friction clutch 1 has the release mechanism 41, which enables disengagement of the friction clutch 1, which is engaged under centrifugal force. To this end, the release mechanism 41 has the release bearing 42, actuated in the axial direction by the driver or automatically, which moves the collar 43 of the cup-shaped load transfer plate 23 against the effect of the spring elements 34 and thereby breaks the frictional engagement between the friction elements 18, 20 brought about by the actuating devices 11, 38.

[0029] FIG. 3 shows, modifying the friction clutch 1 of FIGS. 1 and 2, the friction clutch 1a disposed around the axis of rotation d, in partial sectional view, with the input part 2a and the output part 3a. The engine-side and input-side actuating device 11a with the ramp device 10a, and the transmission-side and output-side actuating device 38a with the ramp device 37a, here act in series on the plate carrier 22a. To this end, the actuating device 38a has the plate piece 32a having the formed ramp 36a, braced axially opposite the plate piece 46a of the input-side actuating device 11a by means of the spring element 47a. Provided axially between the plate piece 32a and a seating surface of the plate carrier 22a are radially movable centrifugal masses 35a, distributed around the circumference, which are moved radially outward as the output part 3a rotates and thereby move the plate carrier 22a against the base plate 24a while tightening the plate pack 21a, and produce a frictional engagement of the friction elements 18a, 20a. Overpressing is avoided by means of the compression springs positioned between the base plate 24a and the plate carrier 22a, corresponding to the compression springs 34 of FIGS. 1 and 2.

[0030] The ramp device 10a of the actuating device 11 a includes the plate piece 44a, firmly connected to the hub piece 4a, which firmly braces the plate piece 45a of the ramp device 10a axially by means of the roller bearing 6a. The plate piece 8a with the ramp 13a is designed to be axially movable, and acts on the plate piece 46a, rotationally uncoupled, by means of the roller bearing 15a. Positioned between the plate pieces 8a, 45a are the radially movable centrifugal masses 9a, which are distributed around the circumference. The plate piece 46a is pre-stressed axially against the plate piece 32a by means of the spring element 47ahere a diaphragm spring. The plate piece 46a is slide-supported on the plate piece 44a by means of the axial extension 48a, and has arms 49a on its end which come to a stop against the hub plate 26a after the plate piece 46a has moved a specified distance. This limits the travel of the actuating device 11a, and brings about a pressure on the plate pack 21a due to centrifugal force, by means of an axially rigid connection through the plate piece 36a and the centrifugal masses 35a. If the output part 3a reaches a specified rotational speed, the centrifugal masses 35a move radially outward and pre-stress the plate pack 21a further. When the rotational speed at the input part 2a is reduced, for example by letting up on the gas to the engine, the plate piece moves back from the hub plate 26a, for example when the engine is idling; the plate pack 21a is pre-stressed by the actuating device 32a when the motor vehicle is moving, however.

[0031] FIG. 4 shows the friction clutch 1b in schematic sectional view, with the input part 2b and the output part 3b and the input-side and engine-side actuating device 11b and the output-side and transmission-side actuating device 38b. To form the actuating devices 11b, 38b, centrifugal masses 9b, 35b rotatably supported eccentrically on the input part 2b and output part 3b are included, which rotate under the centrifugal influence of the rotating input part 2b or output part 3b, and form a frictional engagement radially outside with an opposing friction surface of the other componentoutput part 3b or input part 2b. This achieves a frictional engagement between input part 2b and output part 3b under the influence of centrifugal force, both with input part 2b rotating and with output part 3b rotating.

[0032] FIG. 5 shows diagram 50 of a simulation of a driving-off behavior of a motor vehicle of rotational speed n over time t, with a conventional friction clutch and the proposed friction clutch 1 of FIGS. 1 and 2. Curve 51 shows the speed of the engine and curve 52 the speed of the transmission with a conventional friction clutch. When driving off at 1500 rpm followed by full throttle, the speed of the engine is increased, and remains essentially constant as the friction clutch engages due to centrifugal force, up to the synchronization point at approximately 6700 rpm. Curve 53 shows the speed of the engine and curve 54 the speed of the transmission with the proposed friction clutch. Here, the engine is accelerated to a high speed, which causes the engine-side actuating device to be actuated due to centrifugal force, corresponding to curve 51. The transmission-side actuating device, which is likewise actuated as the motor vehicle begins to move, reduces the speed of the engine due to the higher load, and the synchronization point is reached at significantly lower speeds of around 3600 rpm. It can also be seen from diagram 50 that the effect of the transmission-side actuating device, as a result of which the speed of the engine is reduced, begins in the range of approximately 2000 rpm, so that at these speeds there is already a frictional engagement between input part and output part, even when the engine-side actuating device is inactive. It goes without saying that the synchronization points of the two actuating devices may be specified variably by appropriate selection of the centrifugal masses.

LIST OF REFERENCE NUMERALS

[0033] 1 friction clutch [0034] 1a friction clutch [0035] 1b friction clutch [0036] 2 input part [0037] 2a input part [0038] 2b input part [0039] 3 output part [0040] 3a output part [0041] 3b output part [0042] 4 hub part [0043] 4a hub part [0044] 5 plate carrier [0045] 6 roller bearing [0046] 6a roller bearing [0047] 7 ring gear [0048] 8 plate piece [0049] 8a plate piece [0050] 9 centrifugal mass [0051] 9a centrifugal mass [0052] 9b centrifugal mass [0053] 10 ramp device [0054] 10a ramp device [0055] 11 actuating device [0056] 11a actuating device [0057] 11b actuating device [0058] 12 stamping [0059] 13 ramp [0060] 13a ramp [0061] 14 extension [0062] 15 roller bearing [0063] 15a roller bearing [0064] 16 thrust ring [0065] 17 friction plate [0066] 18 friction element [0067] 18a friction element [0068] 19 steel plate [0069] 20 friction element [0070] 20a friction element [0071] 21 plate pack [0072] 21a plate pack [0073] 22 plate carrier [0074] 22a plate carrier [0075] 23 cup-shaped load transfer plate [0076] 24 base plate [0077] 24a base plate [0078] 25 bolt [0079] 26 hub plate [0080] 26a hub plate [0081] 27 thrust ring [0082] 28 transmission input shaft [0083] 29 plate piece [0084] 30 bolt [0085] 31 leaf spring [0086] 31a leaf spring [0087] 32 plate piece [0088] 32a plate piece [0089] 33 bolt [0090] 34 spring element [0091] 35 centrifugal mass [0092] 35a centrifugal mass [0093] 35b centrifugal mass [0094] 36 ramp [0095] 36a ramp [0096] 37 ramp device [0097] 37a ramp device [0098] 38 actuating device [0099] 38a actuating device [0100] 38b actuating device [0101] 39 bolt [0102] 40 stamping [0103] 41 release mechanism [0104] 42 release bearing [0105] 43 collar [0106] 44a plate piece [0107] 45 plate piece [0108] 45a plate piece [0109] 46a plate piece [0110] 47a spring element [0111] 48a extension [0112] 49a arm [0113] 50 diagram [0114] 51 curve [0115] 52 curve [0116] 53 curve [0117] 54 curve [0118] d axis of rotation [0119] n speed of rotation [0120] t time