DE102022133281B4 - clutch with preloaded actuating device - Google Patents

Abstract

Coupling (1) comprising:
- a housing (2),
- a clutch disc (3),
- a pressure plate (4),
- several actuating devices (5), and
- a spring accumulator (6), wherein in a closed state of the clutch (1) the clutch disc (3) is clamped between a friction surface (7) of the housing (2) and a friction surface (8) of the pressure plate (4) by a force generated by the spring accumulator (6), wherein in a separated state of the 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 (6), wherein the actuating devices (5) each have an actuating lever (9), an intermediate lever (10) and a preload spring (16), wherein the actuating lever (9) has a first end (11) and a second end (12), wherein the actuating lever (9) is mounted on the housing (2) at the first end (11), wherein the intermediate lever (10) has a first end (13) and a second end (14), wherein the intermediate lever (10) at the first end (13) engages the pressure plate (4) and engages the housing (2) at the second end (14), wherein the actuating lever (9) and the intermediate lever (10) are coupled to one another at a coupling point (15), and wherein the intermediate lever (10) is prestressed via the preload spring (16) in that the preload spring (16) engages the intermediate lever (10), characterized in that the preload spring (16) engages the housing (2) on the one hand and engages the intermediate lever (10) between the coupling point (15) and the second end (14) of the intermediate lever (10) on the other hand.

Description

The invention relates to a clutch, in particular for a motor vehicle. The clutch has in particular a pre-tensioned actuating device.

Tractor double clutches are known in which one of the partial clutches is formed from a friction surface on a housing, a friction surface on an axially movable pressure plate and a clutch disc in between. The pressure plate is subjected to a pressure force by a spring accumulator, for example a disc spring. The direction of the pressure force is oriented in such a way that the clutch disc is clamped between the friction surfaces of the pressure plate and the housing for torque transmission. In order to open this partial clutch, i.e. to separate it, the pressure plate must be moved against the force of the spring accumulator. Several actuating levers are usually used for this purpose. The actuating levers are each mounted on the housing with a swivel joint and are driven at their tips by an actuating bearing. The actuating levers are connected to the pressure plate by a respective pressure lever, so that the clutch can be separated via the actuating levers. If the force of the actuating bearing used for this is reduced, the force of the spring accumulator can press the pressure plate against the clutch disc. The clutch is then closed. The actuating levers and the actuating bearing are also moved back via the pressure levers.

If the partial clutch is not operated, the tips of the actuating levers should lift off the actuating bearing. To do this, the actuating bearing is moved back far enough so that a gap forms between the tips of the actuating levers and the actuating bearing. This 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 avoid 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. This means that the actuating levers are preloaded in the direction of the disengagement movement by this force. This ensures a constant gap between the tips of the actuating levers and the actuating bearing. Furthermore, the preload means that the contact points of the actuating levers are permanently on the pressure plate, so that no disadvantageous joint play has to be overcome during an actuation path.

However, this design is problematic if there is a radial offset of the pressure plate in the housing. This can occur, for example, due to play in the axial guide. The radial offset of the pressure plate causes an axial displacement of the tips of the actuating levers, which varies in intensity for each actuating lever. This effect is known as tip runout. If the actuating bearing is moved, this does not result in a uniform movement of the actuating levers. This has a detrimental effect on the movement of the pressure plate and can lead to disruptive clutch properties, for example uncomfortable disengagement of the clutch.

From the DE 2357 860 C2 and DE 31 42 107 A1 There are known approaches to solving this problem. Intermediate levers are used which are mounted on the actuating lever via a swivel joint. If the pressure plate in the housing is moved radially, there is no reaction to the lever positions. A preload spring must also be used for these arrangements with an intermediate lever. If the force generated by the preload spring acts on the actuating lever, the required function, i.e. securing the components at the joint points, is fulfilled. The disadvantage is that the preload spring on the actuating lever follows the entire range of motion. The latter is made up of a disengagement path and any additional wear path. This means that during operation, an oscillation path can occur during the disengagement and engagement movement, and further offset can also occur over the wear area. The working range of the spring must be dimensioned accordingly and is therefore considerably large. The consequences are that the spring must be designed accordingly and that there is a large change from the required minimum spring force to the maximum spring force. However, since the force generated by the preload spring counteracts the force generated by the spring accumulator, functional disadvantages arise for the clutch as a whole. The usable contact pressure of the clutch disc on the friction surfaces is reduced, which reduces the torque transmission. In addition, the contact pressure changes due to wear over the operating period.

From the DE 100 11 412 A1 A coupling is known which can be read in the preamble of claim 1.

The aim of the present invention is to provide a reliable, robust and cost-effective coupling. In particular, it is to prevent a radial offset of the pressure plate in the housing from having a disruptive effect on the operating lever positions, especially in the form of a peak impact. Furthermore, the load on the preload spring should be reduced.

This object is achieved with the coupling according to the independent claim. Further advantageous embodiments are specified in the dependent claims. The features presented in the claims and in the description can be combined with one another in any technologically reasonable manner.

• - ein Gehäuse,
• - eine Kupplungsscheibe,
• - eine Anpressplatte,
• - mehrere Betätigungseinrichtungen, und
• - einen Federspeicher,

wobei in einem geschlossenen Zustand der Kupplung die Kupplungsscheibe durch eine von dem Federspeicher erzeugte Kraft zwischen einer Reibfläche des Gehäuses und einer Reibfläche der Anpressplatte eingeklemmt ist, wobei in einem getrennten Zustand der Kupplung die Anpressplatte über die Betätigungseinrichtungen gegen die von dem Federspeicher erzeugte Kraft von der Kupplungsscheibe getrennt ist, wobei die Betätigungseinrichtungen jeweils einen Betätigungshebel, einen Zwischenhebel und eine Vorlastfeder aufweisen, wobei der Betätigungshebel ein erstes Ende und ein zweites Ende aufweist, wobei der Betätigungshebel am ersten Ende an dem Gehäuse gelagert ist, wobei der Zwischenhebel ein erstes Ende und ein zweites Ende aufweist, wobei der Zwischenhebel am ersten Ende an der Anpressplatte angreift und am zweiten Ende an dem Gehäuse angreift, wobei der Betätigungshebel und der Zwischenhebel an einem Kopplungspunkt miteinander gekoppelt sind, und wobei der Zwischenhebel über die Vorlastfeder vorgespannt ist, indem die Vorlastfeder an dem Zwischenhebel angreift.According to the invention, a coupling is presented which comprises:

• - a housing,
• - a clutch disc,
• - a pressure plate,
• - several operating devices, and
• - a spring accumulator,

wherein in a closed state of the clutch, the clutch disc is clamped between a friction surface of the housing and a friction surface of the pressure plate by a force generated by the spring accumulator, wherein in a separated state of the clutch, the pressure plate is separated from the clutch disc via the actuating devices against the force generated by the spring accumulator, wherein the actuating devices each have an actuating lever, an intermediate lever and a preload spring, wherein the actuating lever has a first end and a second end, wherein the actuating lever is mounted on the housing at the first end, wherein the intermediate lever has a first end and a second end, wherein the intermediate lever engages the pressure plate at the first end and engages the housing at the second end, wherein the actuating lever and the intermediate lever are coupled to one another at a coupling point, and wherein the intermediate lever is preloaded via the preload spring in that the preload spring engages the intermediate lever.

The clutch is preferably designed for a motor vehicle, in particular for a tractor. However, the advantages described herein can generally be achieved in all applications in which a clutch is used. The clutch is designed for a separable connection, for example, between an engine and a transmission.

The clutch can be, for example, a closed, pushed open or pulled on drive clutch or PTO clutch. The clutch can be a single clutch or a double clutch.

The clutch comprises the housing, the clutch disc and the pressure plate. These elements in particular enable the separable connection. When the clutch is closed, the clutch disc is clamped between a friction surface of the housing and a friction surface of the pressure plate. This allows the power to be transmitted from the engine to the transmission, for example. When the clutch is separated, the pressure plate is separated from the clutch disc.

The above functionality implies that the friction surfaces of the housing and the pressure plate are arranged opposite each other and parallel to each other. The clutch disc is arranged between the friction surface of the housing and the friction surface of the pressure plate. When the clutch is closed, the clutch disc rests on the friction surface of the housing on the one hand and on the friction surface of the pressure plate on the other. The pressure plate and the clutch discs are axially movable. Thus, when the clutch is closed, the clutch disc can be clamped between the pressure plate and the housing and the pressure plate can be separated from the clutch disc when the clutch is separated.

It also includes the spring accumulator. The spring accumulator serves to generate a force by which the clutch disc is clamped between the friction surface of the housing and the friction surface of the pressure plate. As long as no other force counteracts the force generated by the spring accumulator, the clutch is in its closed state. This can also be referred to as a basic state. The spring accumulator can, for example, be formed by a spring which preloads the pressure plate in the direction of the clutch disc. The spring is preferably a disc spring. However, the functioning of the clutch described does not depend on the principle according to which the spring accumulator generates the force. The spring accumulator could also be referred to generally as a spring or as a force generating device.

The clutch also includes several actuating devices. The actuating devices can generate a force that counteracts the force generated by the spring accumulator. The actuating devices can therefore be used to move the clutch from its closed state to its separated state. Since the pressure plate is pre-tensioned by the spring accumulator, the clutch returns to its closed state as soon as no more force is exerted on the pressure plate via the actuating devices. The actuating devices can for example, via an actuating bearing.

The actuating devices each have an actuating lever, an intermediate lever and a preload spring. Where a single actuating device is discussed herein, this description applies to the multiple actuating devices.

The actuating lever and the intermediate lever are coupled in such a way that a force can be exerted on the pressure plate via the actuating lever and the intermediate lever. The forces generated by the actuating devices together result in the force that counteracts the force generated by the spring accumulator and with which the clutch can be transferred from its closed state to its released state or with which the clutch can be held in its released state.

The actuating lever has a first end and a second end. The actuating lever therefore extends between its first end and its second end. At the first end, the actuating lever is mounted on the housing, preferably via a pivot bearing. The actuating device can be actuated by acting on the second end of the actuating lever. The second end of the actuating lever is preferably moved in the direction of the pressure plate. At the second end, the actuating lever preferably has a lever tip.

The intermediate lever has a first end and a second end. The intermediate lever therefore extends between its first end and its second end. At the first end, the intermediate lever engages the pressure plate, preferably via a first sliding joint. However, the functionality described is also achieved without the first sliding joint. The second end of the intermediate lever preferably engages an adjusting screw which is part of the pressure plate. The point of engagement of the second end of the intermediate lever on the pressure plate can be axially adjusted using the adjusting screw. At the second end, the intermediate lever engages the housing, preferably via a second sliding joint. However, the functionality described is also achieved without the second sliding joint. The first end of the intermediate lever preferably engages an engagement surface on the housing.

The actuating lever and the intermediate lever are coupled to one another at a coupling point. If the second end of the actuating lever is acted upon, this is transmitted via the actuating lever, via the coupling point and via the intermediate lever to the pressure plate. In this respect, the actuating lever and the intermediate lever work together to generate a force on the pressure plate when a force is acted upon the second end of the actuating lever. The actuating lever and the intermediate lever are therefore part of the actuating device.

With the described coupling, a disruptive reaction to the actuating device can be particularly low or even completely avoided if the pressure plate is radially offset in the housing. This particularly applies to the so-called peak impact. In such an event, the second ends of the actuating levers of the multiple actuating devices would be axially displaced relative to one another. However, this can be avoided or at least reduced by the described design of the coupling.

This is achieved by the combination of the operating lever and the intermediate lever and in particular by the fact that the intermediate lever is preloaded via the preload spring. A force generated by the preload spring acts directly on the intermediate lever. The intermediate lever is therefore not preloaded indirectly via the operating lever, but directly via the preload spring. The preload spring could also be generally referred to as a spring. The preload spring preloads the intermediate lever in the direction of the pressure plate. The force generated by the preload spring therefore counteracts the force generated by the spring accumulator.

The preload spring presses the first end of the intermediate lever onto the pressure plate and the second end of the intermediate lever onto the housing. The intermediate lever is therefore kept in constant contact with the pressure plate or the housing at both ends. This prevents the intermediate lever from lifting off. This is especially true if sliding joints are formed at the ends of the intermediate lever. Furthermore, the coupling of the intermediate lever and the actuating lever also secures the position of the actuating lever. The position of the actuating device is also secured in this way when centrifugal forces, axial forces or other effects occur. Unwanted contact with an actuating bearing, for example due to the intermediate lever being lifted off, is thus reliably avoided. In this respect, the coupling described is functionally reliable and robust. Since this is achieved in a comparatively simple manner, the coupling described is also correspondingly inexpensive.

According to the invention, the preload spring engages on the one hand on the housing and on the other hand between between the coupling point and the second end of the intermediate lever.

The point of attachment of the preload spring to the intermediate lever is thus selected in such a way that a particularly small range of motion is achieved for the preload spring. This makes it possible to achieve an advantageously reduced load on the preload spring. This makes it easier to design the preload spring. Furthermore, by reducing the range of motion of the preload spring, an advantageously smaller change in the preload force is achieved and thus also an advantageously small difference between the new and worn condition of the clutch in terms of clutch parameters.

In a further preferred embodiment of the coupling, the actuating lever and the intermediate lever are coupled to one another at the coupling point via a rotary joint.

As an alternative to the present embodiment, any other type of force transmission between the operating lever and the intermediate lever can also be considered. In the simplest case, the operating lever and the intermediate lever simply lie against each other. However, coupling via a swivel joint is safer and more robust.

In a further preferred embodiment of the coupling, the preload spring is a leg spring.

It has been found that the coupling with a leg spring can be manufactured particularly easily and inexpensively.

In a further preferred embodiment of the coupling, the first end of the actuating lever and the first end of the intermediate lever are each arranged radially further outward than the coupling point, wherein the second end of the actuating lever and the second end of the intermediate lever are each arranged radially further inward than the coupling point.

If the first end of the actuating lever is pressed in the direction of the pressure plate, this is transmitted in the present embodiment via the intermediate lever to the pressure plate in such a way that the pressure plate is moved away from the clutch disc.

In a further preferred embodiment of the coupling, the second end of the intermediate lever is arranged radially further outward than the second end of the actuating lever.

In this embodiment in particular, the intermediate lever can be made shorter than the actuating lever. This is advantageous in that the actuating lever can be actuated relatively far inward radially. The actuating levers of the multiple actuating devices can thus be actuated close to one another.

In a further preferred embodiment of the coupling, the preload spring is designed as a compression spring, wherein the preload spring acts on the housing at an attack point, wherein the attack point and the pressure plate are arranged axially on different sides of the coupling point.

In this design, the preload spring pushes the intermediate lever towards the pressure plate.

In a further preferred embodiment, the coupling is designed as a tractor coupling.

• 1: einen Teil einer aus dem Stand der Technik bekannten Kupplung in einer seitlichen Schnittdarstellung,
• 2: ein kinematisches Schema der in 1 gezeigten bekannten Kupplung,
• 3: einen Teil einer erfindungsgemäßen Kupplung in einer seitlichen Schnittdarstellung,
• 4: die in 3 gezeigte erfindungsgemäße Kupplung in einer perspektivischen Darstellung,
• 5: ein kinematisches Schema der in 3 und 4 gezeigten Kupplung,
• 6: einen Teil der erfindungsgemäßen Kupplung aus 3 und 4 in einer seitlichen Schnittdarstellung, und
• 7: die Darstellung aus 6 für verschiedene Zustände.

The invention is described below with reference to 3 to 7 explained in more detail. The 3 to 7 show a particularly preferred embodiment, to which the invention is not limited. The 3 to 7 and the proportions shown therein are only schematic. They show:

• 1 : a part of a coupling known from the prior art in a side sectional view,
• 2 : a kinematic scheme of the 1 known coupling shown,
• 3 : a part of a coupling according to the invention in a side sectional view,
• 4 : the in 3 shown coupling according to the invention in a perspective view,
• 5 : a kinematic scheme of the 3 and 4 shown coupling,
• 6 : a part of the coupling according to the invention 3 and 4 in a lateral sectional view, and
• 7 : the representation from 6 for different conditions.

1 shows a part of a clutch 1 known from the prior art. This is a tractor double clutch. The clutch 1 has a housing 2, a clutch disc 3, a pressure plate 4, several actuating devices 5 (one of which is shown in the cutout of the 1 can be seen), and a spring accumulator 6. In the closed state of the clutch 1 shown, the clutch disc 3 is clamped between a friction surface 7 of the housing 2 and a friction surface 8 of the pressure plate 4 by a force generated by the spring accumulator 6. In a position not shown In the separated state of the 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 6. The actuating devices 5 each have an actuating lever 9 and a pressure lever 21.

2 shows a kinematic scheme of the 1 shown known clutch 1. The upper image serves to explain the elements. An actuating lever 9 and a pressure lever 21 coupled to it are shown, which together form one of the actuating devices 5. The actuating lever 9 is mounted at its left end on the housing 2. The pressure lever 10 is mounted on the one hand on the actuating lever 9 and on the other hand on the pressure plate 4. The pressure plate 4 rests on the left side of the housing 2.

In the middle picture of the 2 Two of the actuating devices 5 are shown opposite one another. The pressure plate 4 is centered in this case. This represents the ideal state. The tips of the two actuating levers 9 shown are at the same height.

In the picture below the 2 the situation with radial offset of the pressure plate 4 is shown. It can be seen that the tips of the two actuating levers 9 shown are no longer at the same height. This concerns the so-called tip runout.

3 shows a part of a coupling 1 according to the invention. As with the coupling 1 from 1 This is a tractor double clutch. In contrast to clutch 1 from 1 The operating devices 5 (of which also in 3 only one is visible) at clutch 1 from 3 each has an actuating lever 9, an intermediate lever 10 and a preload spring 16. The actuating lever 9 and the intermediate lever 10 are coupled to one another. The intermediate lever 10 is preloaded via the preload spring 16. The intermediate lever 10 engages the housing 2 and an adjusting screw 19 of the pressure plate 4 on the pressure plate 4.

4 shows the 3 shown clutch 1. The housing 2, the pressure plate 4, the actuating devices 5 with the actuating levers 9, the intermediate levers 10 and the preload springs 16 as well as the adjusting screws 19 can also be seen there.

5 shows a kinematic scheme of the 3 and 4 shown clutch 1. It can be seen that the actuating lever 9 has a first end 11 and a second end 12. The actuating lever 9 is mounted on the housing 2 at the first end 11. The intermediate lever 10 has a first end 13 and a second end 14. The intermediate lever 10 engages the pressure plate 4 at the first end 13 and the housing 2 at the second end 14. The actuating lever 9 and the intermediate lever 10 are coupled to one another at a coupling point 15 via a swivel joint 17. It can also be seen that the preload spring 16 engages the housing 2 at an engagement point 18 on the one hand and engages the intermediate lever 10 between the coupling point 15 and the second end 14 of the intermediate lever 10 on the other.

6 shows the 3 shown clutch 1. It shows the housing 2, the pressure plate 4 and one of the actuating devices 5 with the actuating lever 9, the intermediate lever 10 and the preload spring 16. Furthermore, a force F is indicated which the preload spring 16 exerts directly on the intermediate lever 10. This force enables the intermediate lever 10 to be secured at its two ends 13, 14, which would otherwise not be secured.

In 7 clutch 1 is off 6 in three different states. When the clutch 1 is separated, the operating lever 9 is in the lower of the three positions shown. When the clutch 1 is closed, the operating lever 9 is in the middle of the three positions shown, provided that the clutch 1 is new and not worn. If, however, the clutch 1 is worn, the operating lever 9 is in the upper of the three positions shown when the clutch 1 is closed. 7 It can be seen that the preload spring 16 has an advantageously small range of motion 20.

List of reference symbols

1

coupling

2

Housing

3

clutch disc

4

pressure plate

5

actuator

6

spring-loaded mechanism

7

friction surface of the housing

8

friction surface of the pressure plate

9

operating lever

10

intermediate lever

11

first end of the operating lever

12

second end of the operating lever

13

first end of the intermediate lever

14

second end of the intermediate lever

15

coupling point

16

preload spring

17

swivel joint

18

point of attack

19

adjustment screw

20

range of motion

21

pressure lever

Claims (7)

Clutch (1) comprising: - a housing (2), - a clutch disc (3), - a pressure plate (4), - several actuating devices (5), and - a spring accumulator (6), wherein in a closed state of the clutch (1) the clutch disc (3) is clamped between a friction surface (7) of the housing (2) and a friction surface (8) of the pressure plate (4) by a force generated by the spring accumulator (6), wherein in a separated state of the 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 (6), wherein the actuating devices (5) each have an actuating lever (9), an intermediate lever (10) and a preload spring (16), wherein the actuating lever (9) has a first end (11) and a second end (12), wherein the actuating lever (9) is mounted on the housing (2) at the first end (11), wherein the Intermediate lever (10) has a first end (13) and a second end (14), wherein the intermediate lever (10) engages the pressure plate (4) at the first end (13) and engages the housing (2) at the second end (14), wherein the actuating lever (9) and the intermediate lever (10) are coupled to one another at a coupling point (15), and wherein the intermediate lever (10) is prestressed via the preload spring (16) in that the preload spring (16) engages the intermediate lever (10), characterized in that the preload spring (16) engages the housing (2) on the one hand and engages the intermediate lever (10) between the coupling point (15) and the second end (14) of the intermediate lever (10) on the other hand. Clutch (1) after Claim 1 , wherein the actuating lever (9) and the intermediate lever (10) are coupled to one another at the coupling point (15) via a rotary joint (17). Coupling (1) according to one of the preceding claims, wherein the preload spring (16) is a leg spring. Coupling (1) according to one of the preceding claims, wherein the first end (11) of the actuating lever (9) and the first end (13) of the intermediate lever (10) are each arranged radially further outward than the coupling point (15), and wherein the second end (12) of the actuating lever (9) and the second end (14) of the intermediate lever (10) are each arranged radially further inward than the coupling point (15). Coupling (1) according to one of the preceding claims, wherein the second end (14) of the intermediate lever (10) is arranged radially further outward than the second end (12) of the actuating lever (9). Coupling (1) according to one of the preceding claims, wherein the preload spring (16) is designed as a compression spring, wherein the preload spring (16) acts on the housing (2) at an engagement point (18), and wherein the engagement point (18) and the pressure plate (4) are arranged axially on different sides of the coupling point (15). Coupling (1) according to one of the preceding claims, which is designed as a tractor coupling.

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