Friction clutch

Abstract

Friction clutch (1) comprising a housing (2), a housing-fixed counter-pressure plate (6), a pressure plate (4) which is axially displaceable (A) of the friction clutch (1), several actuating devices (5), a spring accumulator (15) and a clutch disc (3), wherein in an engaged state of the friction clutch (1) the clutch disc (3) is frictionally clamped between the counter-pressure plate (6) and the pressure plate (4) by a force generated by the spring accumulator (15), wherein in a disengaged state of the friction clutch (1) the pressure plate (4) is separated from the clutch disc (3) via the actuating devices (5) against the force generated by the spring accumulator (15), wherein each of the actuating devices (5) comprises an actuating lever (9) and an intermediate lever (10),wherein an outer end (11) of the actuating lever (9) in the radial direction (R) of the friction clutch (1) is rotatably attached to the housing (2) via an actuating bearing (16), wherein the intermediate lever (10) has a first end (13) outer in the radial direction (R) and a second end (14) inner in the radial direction (R), wherein the intermediate lever (10) acts on the pressure plate (4) at the first end (13) and engages the counter-pressure plate (6) at the second end (14), wherein the intermediate lever (10) is rotatably attached to the actuating lever (9) via an intermediate bearing (17), and wherein a first lever section (18) of the intermediate lever (10), which extends in the radial direction (R) between the intermediate bearing (17) and the first end (13), extends in the axial direction (A) further from the pressure plate (4), in particular from the counter-pressure plate, than the actuating bearing (16). (6) removed, characterized by this,that the first end (13) of the intermediate lever (10) is arranged further outwards in the radial direction (R) than the actuating bearing (16).

Description

[0001] The present invention relates to a friction clutch, in particular for a motor vehicle, preferably a tractor clutch.

[0002] Dual-clutch transmissions for tractors are known in which one of the partial clutches consists of a friction surface on a housing, a friction surface on an axially movable pressure plate, and a clutch disc positioned between them. The pressure plate is subjected to a clamping force by a spring accumulator, for example, a disc spring. The direction of the clamping force is such that the clutch disc is clamped between the friction surfaces of the pressure plate and the housing for torque transmission. To disengage this partial clutch, the pressure plate must be moved against the force exerted by the spring accumulator.

[0003] This typically involves the use of several actuating levers. Each actuating lever is mounted to the housing via a pivot joint and is driven at its tip by an actuating bearing. The actuating levers are connected to the pressure plate by a respective push lever, allowing the friction clutch to be disengaged via the actuating levers. When the force applied to the actuating bearing is reduced, the force from the spring accumulator presses the pressure plate against the clutch disc, thus engaging the friction clutch. The actuating levers and the actuating bearing are also moved back via the push levers.

[0004] When the partial clutch is not actuated, the tips of the actuating levers should lift off the actuating bearing. For this purpose, the actuating bearing is moved back sufficiently to create a gap between the tips of the actuating levers and the actuating bearing. This gap is intended to reduce wear and prevent vibrations. However, centrifugal forces or axial vibrations can cause the tips of the actuating levers to come into contact with the actuating bearing. To prevent this, it is known to preload the actuating levers with preload springs. The preload springs generate a force that moves the actuating levers towards the pressure plate. In other words, the actuating levers are preloaded by this force in the direction of the disengagement movement. This ensures a constant gap between the tips of the actuating levers and the actuating bearing.Furthermore, due to the preload, the contact points of the actuating levers are permanently in contact with the pressure plate, so that no adverse joint play has to be overcome during an actuation movement.

[0005] This design, however, becomes problematic if there is a radial offset of the pressure plate within the housing. Such an offset can arise, for example, from play in the axial guide. The radial offset of the pressure plate causes an axial displacement of the actuating lever tips, which varies in intensity between individual actuating levers. This effect is known as tip flex. When the actuating bearing is moved, this does not result in a uniform movement of the actuating levers. This negatively affects the movement of the pressure plate and can lead to undesirable clutch characteristics, such as uncomfortable disengagement of the friction clutch.

[0006] Approaches to solving this problem are known from DE 23 57 860 C2 and DE 31 42 107 A1. These approaches use intermediate levers mounted on the actuating lever via a pivot joint. This prevents any radial displacement of the pressure plate within the housing from affecting the lever positions. A preload spring must also be used in these arrangements with an intermediate lever. When the force generated by the preload spring acts on the actuating lever, the required function, i.e., securing the components against the pivot points, is fulfilled. In particular, a friction clutch is known from DE 31 42 107 A1, which can be read as referring to the preamble of claim 1.

[0007] A disadvantage of the preload spring's position on the actuating lever is that it follows the entire range of motion. This range consists of the disengagement travel and any additional wear travel. This means that during operation, an oscillation and, due to the wear range, further displacement can occur during the engagement and disengagement movements. The spring's operating range must be dimensioned accordingly and is therefore considerably large. Consequently, the spring must be designed accordingly, and a significant change occurs between the required minimum spring force and the maximum spring force. Since the force generated by the preload spring opposes the force generated by the spring accumulator, functional disadvantages arise for the friction clutch as a whole. The usable contact force of the clutch disc against the friction surfaces is reduced, thereby decreasing torque transmission.Furthermore, the contact force changes due to wear over the operating period.

[0008] The object of the present invention is to provide a reliable, robust, and cost-effective friction clutch. In particular, it aims to prevent any disruptive feedback on the actuating lever positions, especially in the form of a crease, caused by radial misalignment of the pressure plate within the housing. Furthermore, the friction clutch should be designed to be compact in the axial direction.

[0009] According to the invention, this problem is solved by a friction clutch according to claim 1 comprising a housing, a housing-fixed counter-pressure plate, a pressure plate that is axially displaceable within limits in the friction clutch, several actuating devices, a spring accumulator, and a clutch disc, wherein in an engaged state of the friction clutch, the clutch disc is frictionally clamped between the counter-pressure plate and the pressure plate by a force generated by the spring accumulator, wherein in a disengaged state of the friction clutch, the pressure plate is separated from the clutch disc against the force generated by the spring accumulator via the actuating devices, wherein each of the actuating devices comprises an actuating lever and an intermediate lever, wherein an outer end of the actuating lever in the radial direction of the friction clutch is rotatably attached to the housing via an actuating bearing.wherein the intermediate lever has a radially outer first end and a radially inner second end, wherein the intermediate lever acts on the pressure plate at its first end and engages the counter-pressure plate at its second end, and wherein the intermediate lever is rotatably attached to the actuating lever via an intermediate bearing.

[0010] Since a first lever section of the intermediate lever, which extends radially between the intermediate bearing and the first end, is located further axially from the pressure plate, and in particular from the counter-pressure plate, than the actuating bearing, the friction clutch can, on the one hand, prevent crease and, on the other hand, still be compact in the axial direction. More precisely, in this arrangement, the position of the actuating bearing does not define the axial installation space occupied by the friction clutch according to the invention.

[0011] According to the invention, the first end of the intermediate lever is arranged further outwards in the radial direction than the actuating bearing. This enables a compact design of the friction clutch.

[0012] Preferred embodiments of the friction clutch according to the invention are set out in the dependent claims.

[0013] Preferably, each of the actuating devices has a preload spring by which the actuating lever and / or the intermediate lever is / are preloaded by the preload spring acting on the actuating lever and / or the intermediate lever. This enables a compact and robust design of the friction clutch.

[0014] Preferably, the preload spring engages the housing on one side and the intermediate lever between the intermediate bearing and the second end of the intermediate lever on the other. This allows for a compact and robust design of the friction clutch.

[0015] Furthermore, the preload spring is preferably a torsion spring. This allows for a compact and robust design of the friction clutch.

[0016] It is advantageous if the actuating bearing is positioned further outwards in the radial direction than the intermediate bearing. This allows for a compact design of the friction clutch.

[0017] It is particularly advantageous if the first lever section of the intermediate lever engages the actuating bearing on its side facing away from the counter-pressure plate. This allows for a compact design of the friction clutch.

[0018] Furthermore, it is particularly advantageous if the intermediate lever also has an intermediate section extending radially between the intermediate bearing and the first end of the intermediate lever, and arranged axially on the side of the actuating bearing facing the counter-pressure plate, so that the first lever section and the intermediate section define an enclosed area of ​​the intermediate lever, inside of which the actuating bearing is arranged, via which the actuating lever is rotatably attached to the housing. This allows for a compact design of the friction clutch even with high expected actuating forces.

[0019] Preferably, when the friction clutch is new and engaged, the axial distance between the actuating bearing and the first lever section of the intermediate lever is smaller than when the friction clutch is worn. This allows for a more compact design of the friction clutch.

[0020] Furthermore, preferably, in the new condition of the friction clutch, the axially measured distance between the actuating bearing and the first lever section of the intermediate lever is smaller in the disengaged state of the friction clutch than in the engaged state. This allows for a compact design of the friction clutch.

[0021] Preferably, the housing and the counter-pressure plate are formed as a single piece. This allows for a compact design of the friction clutch.

[0022] The present invention is explained in more detail below with reference to preferred, schematically illustrated embodiments in conjunction with the accompanying figures. These show: Fig. 1: A first embodiment of a friction clutch with an actuating lever and an intermediate lever in the new condition in the engaged state, Fig. 2: the friction clutch Fig. 1 in the deployed state, Fig. 3: the friction clutch Fig. 1 in the worn state in the engaged state, and Fig. 4: a second embodiment of a friction clutch with an actuating lever and an intermediate lever.

[0023] The Fig. Figures 1 to 3 show a schematic representation of a first embodiment of a friction clutch 1, which is in particular a tractor clutch, preferably a partial clutch of a tractor double clutch. In the Fig. 1 and Fig. Figure 2 shows the friction clutch 1 in its new condition, where it is in Fig. 1 is indented and in Fig. 2 has been dispatched. In Fig. Figure 3 shows the friction clutch 1 in its worn state and in its engaged state.

[0024] The friction clutch 1 is rotatable about an axis of rotation D and has a housing 2. A pressure plate 4, which is displaceable within limits in the axial direction A of the friction clutch 1, is arranged in the housing 2. Furthermore, a counter-pressure plate 6, which is fixed in the axial direction A, i.e., fixed to the housing, is arranged in the housing 2 and may preferably be formed integrally with the housing 2.

[0025] The friction clutch 1 further comprises several actuating devices 5 arranged in the circumferential direction of the friction clutch 1, a spring accumulator 15 (schematically shown in the Fig. (1 to 3 shown as arrows) and a clutch disc 3. In an engaged state of the friction clutch 1, the clutch disc 3 is frictionally clamped by a force generated by the spring accumulator 15 between the counter-pressure plate 6, more precisely between a friction surface 7 of the counter-pressure plate 6, and the pressure plate 4, more precisely between a friction surface 8 of the pressure plate 4. The spring accumulator 15 acts indirectly or directly on the pressure plate 4, which is axially displaceable within a limited range in direction A, in the form of coil springs, leaf springs, or a disc spring.

[0026] In a disengaged state of the friction clutch 1, the frictional engagement described above between the clutch disc 3 and the pressure plate 4, as well as between the clutch disc 3 and the counter-pressure plate 6, is suspended. The pressure plate 4 is separated from the clutch disc 3 against the force generated by the spring accumulator 15 via the actuating devices 5. For example, the actuating devices 5 can act on the pressure plate 4 via circumferentially distributed push rods 20, which are axially displaceable in direction A, in order to move the pressure plate 4 away from the counter-pressure plate 6 in the axial direction A.

[0027] Each of the actuating devices 5 has an actuating lever 9 and an intermediate lever 10. Furthermore, each of the actuating devices 5 can have a lever not located in the Fig. The preload spring shown in Figures 1 to 3 preloads the actuating lever 9 and / or the intermediate lever 10 by means of which the preload spring acts on the actuating lever 9 and / or the intermediate lever 10 on one side and is supported on the housing 2 and / or the counter-pressure plate 6 on the other. Preferably, the preload spring is designed as a torsion spring or as a helical spring.

[0028] An outer end 11 of the actuating lever 9, located in the radial direction R of the friction clutch 1, is rotatably attached to the housing 2 via an actuating bearing 16. An inner end 12 of the actuating lever 9, located in the radial direction, has an actuating dome that can be brought into contact with a release bearing of a release device, which can be displaced in the axial direction A.

[0029] The intermediate lever 10 has a first end 13 located radially outside in the direction R and a second end 14 located radially inside in the direction R. The intermediate lever 10 acts on the pressure plate 4 at its first end 13, preferably via a first lever tip which is in contact with the push rod 20. Furthermore, the intermediate lever 10 engages the counter-pressure plate 6 at its second end 14, preferably via a second lever tip.

[0030] The intermediate lever 10 is rotatably attached to the actuating lever 9 via an intermediate bearing 17, which is arranged between the first end 13 and the second end 14 of the intermediate lever 10. Thus, a first lever section 18 of the intermediate lever 10 extends radially in direction R between the intermediate bearing 17 and the first end 13, while a second lever section 19 of the intermediate lever 10 extends radially in direction R between the intermediate bearing 17 and the second end 14. The aforementioned preload spring preferably engages the housing 2 on one side and the intermediate lever 10 on the other side between the intermediate bearing 17 and the second end 14, i.e., in the second lever section 19.

[0031] The first lever section 18 of the intermediate lever 10 is located further in axial direction A than the actuating bearing 16 from the pressure plate 4, in particular from the counter-pressure plate 6. That is, the actuating bearing 16 is arranged in axial direction A between the pressure plate 4 or the counter-pressure plate 6 and the first lever section 18 of the intermediate lever 10. Specifically, the first lever section 18 of the intermediate lever 10 engages the actuating bearing 16 on its side facing away from the counter-pressure plate 6.

[0032] In particular, the actuating bearing 16 is arranged further outwards in the radial direction R than the intermediate bearing 17. Furthermore, the first end 13 of the intermediate lever 10, more precisely the first lever tip, is arranged further outwards in the radial direction R than the actuating bearing 16.

[0033] As can be seen from the comparison of the Fig. 1 and Fig. As can be seen in Figure 2, in the new state of the friction clutch 1, the distance 21 measured in axial direction A between the actuating bearing 16 and the first lever section 18 of the intermediate lever 10 is smaller when the friction clutch 1 is disengaged (see Figure 2). Fig. 2) as in the engaged state of the friction clutch (1) (see Fig. 1).

[0034] As further as can be seen from the comparison of the Fig. 1 and Fig. As can be seen in Figure 3, the friction clutch 1 is in its engaged state when the friction clutch 1 is new (see Figure 3). Fig. 1) a distance measured in axial direction A between the actuating bearing 16 and the first lever section 18 of the intermediate lever 10 is less than in the worn state of the friction clutch 1 (see Fig. 3).

[0035] In Fig. Figure 4 shows a second embodiment of the friction clutch 1. The same reference numerals refer to the same features associated with Fig. 4 will not be explained again.

[0036] The in Fig. The friction clutch 1 shown in Figure 4 differs from the one shown in the Fig. Friction clutch 1 shown in 1 to 3 by the fact that the in Fig. The intermediate lever 10 shown in Figure 4 not only has the first lever section 18, which extends in radial direction R between the intermediate bearing 17 and the outer first end 13 in radial direction R, and the second lever section 19, which extends in radial direction R between the intermediate bearing 17 and the inner second end 14 in radial direction R, but also an intermediate section 22.

[0037] Like the first lever section 18, the intermediate section 22 of the intermediate lever 10 also extends radially in direction R between the intermediate bearing 17 and the radially outer first end 13 of the intermediate lever 10. While the first lever section 18 of the intermediate lever 10 is located further in axial direction A than the actuating bearing 16 from the pressure plate 4, in particular from the counter-pressure plate 6, i.e., on the side of the actuating bearing 16 facing away from the counter-pressure plate 6, the intermediate section 22 of the intermediate lever 10 is formed in axial direction A between the actuating bearing 16 and the pressure plate 4, in particular the counter-pressure plate 6, i.e., on the side of the actuating bearing 16 facing towards the counter-pressure plate 6.

[0038] Thus, the first lever section 18 and the intermediate section 22 define an enclosed area 23 of the intermediate lever 10, inside of which the actuating bearing 16 is arranged, via which the actuating lever 9 is rotatably attached to the housing 2.

[0039] The preceding embodiments relate to a friction clutch 1 with a housing 2, a housing-fixed counter-pressure plate 6, a pressure plate 4 which is displaceable to a limited extent in the axial direction A of the friction clutch 1, several actuating devices 5, a spring accumulator 15 and a clutch disc 3, wherein in an engaged state of the friction clutch 1 the clutch disc 3 is frictionally clamped between the counter-pressure plate 6 and the pressure plate 4 by a force generated by the spring accumulator 15, wherein in a disengaged state of the friction clutch 1 the pressure plate 4 is separated from the clutch disc 3 by the actuating devices 5 against the force generated by the spring accumulator 15, wherein each of the actuating devices 5 has an actuating lever 9 and an intermediate lever 10.wherein an outer end 11 of the actuating lever 9 in the radial direction R of the friction clutch 1 is rotatably attached to the housing 2 via an actuating bearing 16, wherein the intermediate lever 10 has a first end 13 that is outer in the radial direction R and a second end 14 that is inner in the radial direction R, wherein the intermediate lever 10 acts on the pressure plate 4 at the first end 13 and engages the counter-pressure plate 6 at the second end 14, wherein the intermediate lever 10 is rotatably attached to the actuating lever 9 via an intermediate bearing 17, and wherein a first lever section 18 of the intermediate lever 10, which extends in the radial direction R between the intermediate bearing 17 and the first end 13, is located further in the axial direction A than the actuating bearing 16 from the pressure plate 4, in particular from the counter-pressure plate 6. Reference symbol list 1 friction clutch 2 cases 3 Clutch disc 4 pressure plate 5 Actuating device 6 Counter-pressure plate 7 Friction surface of the counter-pressure plate 8 Friction surface of the pressure plate 9 operating levers 10 intermediate levers 11 outer end of the actuating lever in radial direction 12 in radial direction inner end of the actuating lever 13 first end of the intermediate lever 14 second end of the intermediate lever 15 spring storage units 16 actuating bearings 17 interim storage facilities 18 First lever section of the intermediate lever 19 second lever section of the intermediate lever 20 push rod 21 distance 22 Intermediate section 23 completely enclosed area A axial direction D axis of rotation R radial direction

Claims

[1] Friction clutch (1) with a housing (2), a counterpressure plate (6) fixed to the housing, a pressure plate (4) which is displaceable to a limited extent in the axial direction (A) of the friction clutch (1), a plurality of actuating devices (5), a spring-loaded mechanism (15) and a clutch disc (3), wherein, in an engaged state of the friction clutch (1), the clutch disc (3) is clamped frictionally between the counterpressure plate (6) and the pressure plate (4) by a force generated by the spring-loaded mechanism (15), wherein, in a disengaged state of the friction clutch (1), the pressure plate (4) is separated from the clutch disc (3) via the actuating devices (5) against the force generated by the spring-loaded mechanism (15), wherein each of the actuating devices (5) has an actuating lever (9) and an intermediate lever (10),wherein an outer end (11) of the actuating lever (9) in the radial direction (R) of the friction clutch (1) is rotatably fastened to the housing (2) via an actuating bearing (16), wherein the intermediate lever (10) has a first end (13) which is outer in the radial direction (R) and a second end (14) which is inner in the radial direction (R), wherein the intermediate lever (10) acts on the pressure plate (4) at the first end (13) and engages the counterpressure plate (6) at the second end (14), wherein the intermediate lever (10) is rotatably fastened to the actuating lever (9) via an intermediate bearing (17), and wherein a first lever section (18) of the intermediate lever (10), which extends in the radial direction (R) between the intermediate bearing (17) and the first end (13), protrudes in the axial direction (A) further than the actuating bearing (16) from the pressure plate (4), in particular from the Counter pressure plate (6), is removed, , characterized bythat the first end (13) of the intermediate lever (10) is arranged further outwards in the radial direction (R) than the actuating bearing (16). [2] Friction clutch (1) according to claim 1, wherein each of the actuating devices (5) has a preload spring, via which the actuating lever (9) and / or the intermediate lever (10) is / are preloaded by the preload spring acting on the actuating lever (9) and / or the intermediate lever (10). [3] Friction clutch (1) according to claim 2, wherein the preload spring acts on the one hand on the housing (2) and on the other hand on the intermediate lever (10) between the intermediate bearing (17) and the second end (14) of the intermediate lever (10). [4] Friction clutch (1) according to one of claims 1 to 3, wherein the actuating bearing (16) is arranged further outward in the radial direction (R) than the intermediate bearing (17). [5] Friction clutch (1) according to one of claims 1 to 4, wherein the first lever portion (18) of the intermediate lever (10) engages around the actuating bearing (16) on its side facing away from the counterpressure plate (6). [6] Friction clutch (1) according to claim 5, wherein the intermediate lever (10) further comprises an intermediate section (22) which extends in the radial direction (R) between the intermediate bearing (17) and the first end (13) of the intermediate lever (10), and which is arranged in the axial direction (A) on the side of the actuating bearing (16) facing the counterpressure plate (6), so that the first lever section (18) and the intermediate section (22) define an enclosed region (23) of the intermediate lever (10), in the interior of which the actuating bearing (16) is arranged, via which the actuating lever (9) is rotatably fastened to the housing (2). [7] Friction clutch (1) according to one of claims 1 to 6, wherein in the engaged state of the friction clutch (1) in the new state of the friction clutch (1) a distance (21) measured in the axial direction (A) between the actuating bearing (16) and the first lever section (18) of the intermediate lever (10) is smaller than in the worn state of the friction clutch (1). [8] Friction clutch (1) according to one of claims 1 to 7, wherein in the new state of the friction clutch (1) a distance (21) measured in the axial direction (A) between the actuating bearing (16) and the first lever section (18) of the intermediate lever (10) is smaller in the disengaged state of the friction clutch (1) than in the engaged state of the friction clutch (1). [9] Friction clutch (1) according to one of claims 1 to 8, wherein the housing (2) and the counterpressure plate (6) are formed in one piece.

Images