WO2016127997A1

WO2016127997A1 - Friction disc clutch

Info

Publication number: WO2016127997A1
Application number: PCT/DE2016/200092
Authority: WO
Inventors: Joydeep Roy; Arunkumar Natarajan; Suresh KRISHANASWAMY NAIG; Rajagopal Rengasamy
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2015-02-12
Filing date: 2016-02-12
Publication date: 2016-08-18
Also published as: DE102015202522A1

Abstract

A friction disc clutch comprises an input side and an output side which are arranged coaxially about a rotational axis, first frictional elements which are connected to the input side in a torque-transmitting manner, and second frictional elements which are connected to the output side in a torque-transmitting manner. First and second frictional elements are arranged alternately in the axial direction. Furthermore, an actuating element is provided, in order to press the frictional elements together axially, thus making a torque flow possible between the input side and the output side. One elastic element is inserted between each pair of axially adjacent first frictional elements, in order to press the frictional elements axially apart from one another.

Description

friction disc clutch

The invention relates to a friction disc clutch. In particular, the invention relates to a multi-plate friction clutch for use in a motorcycle.

In a motor vehicle, especially a motorcycle, a friction disc clutch is operatively disposed between an internal combustion engine and a transmission to permit or interrupt a torque flow. The friction disc clutch is usually operated manually, so that a Betätigungsweg and an operating force must be limited so that the driver can muster this. The friction disc clutch usually includes a number of first and second friction elements alternately arranged in an axial direction with respect to a rotation axis. The first friction elements have radially outward protrusions to engage an outer beam, while the second friction elements have radially inwardly facing protrusions to engage an inner beam. Outer carrier and inner carrier form the input and output side of the coupling. To close the clutch, the stack of friction elements is axially compressed, so that a frictional connection is created and torque can be transmitted between the input side and the output side.

To open the clutch, the axial contact pressure on the friction elements is reduced. An actuator for axially compressing the stack of friction elements is axially moved only slightly, usually in a range between 1 and 2 mm. Due to manufacturing tolerances, the friction elements usually unevenly lift off when opening the clutch in the axial direction, so that the clutch does not completely separate. When the clutch is in an oil bath, the oil may cause sticking of axially abutting first and second friction elements whereby the torque transmittable between the input side and the output side may undesirably increase.

If an inserted gear ratio is changed in the transmission, then a high load on the gear stages can act through an insufficiently interrupted flow of torque between the internal combustion engine and the transmission. This may be externally noticeable by a crash when changing gears. A ride comfort or a Lifespan of powertrain elements of the motorcycle can thereby be reduced.

It is an object of the present invention to provide a friction disc clutch, which provides an improved separation behavior, preferably at a non-enlarged actuating travel. The invention solves this problem by means of a friction disc clutch with the features of the independent claim. Subclaims give preferred embodiments again.

A friction disc clutch includes an input side and an output side coaxially disposed about a rotation axis, first friction elements that are torque-connected to the input side, and second friction elements that are torque-connected to the output side. First and second friction elements are arranged alternately in the axial direction. Further, an actuator is provided to axially compress the friction elements to allow a torque flow between the input side and the output side. Between axially adjacent first friction elements in each case an elastic element is used to axially compress the friction elements.

An actuation path of the friction disc clutch is dimensioned at a point where the actuation element acts axially on one of the friction elements between an actuated and an unactuated position of the friction disc clutch. Without enlarging the actuation path with respect to a known friction disk clutch, the elastic elements can cause the first friction elements to be raised more uniformly axially from one another when the friction disk clutch is actuated so that they can release the second friction elements in an improved manner. The friction disc clutch can thus have an improved separation behavior. The transmittable in the open, actuated state of the friction disc clutch between the input side and the output side torque can be reduced. For example, the actuation travel can be in the range of approximately 2 mm, whereby the friction disc clutch can not transmit more than approximately 0.5 Nm of torque in the opened state. In a drive train, the friction disc clutch can be advantageously used for improved separation, for example between an internal combustion engine and a transmission. Especially on a motorcycle, where the transmission can be unsynchronized, gear changes with open friction disc clutch can run more gentle, quiet or wear. An actuation path of the friction disc clutch can be in the range of the actuation travel of a known friction disc clutch. Preferably, at least three elastic elements are distributed on a circumference about the axis of rotation between two axially adjacent first friction elements. As a result, tilting of the first friction elements with respect to the axis of rotation can be prevented. A plant of a first friction element on a second friction element along a contact surface, which extends around the axis of rotation, can thereby be improved completely.

It is particularly preferred that the elastic element is formed as a single-layer leaf spring. Thereby, the elastic element can be produced inexpensively. An assembling operation of the elastic member to the friction disc clutch may be simplified.

An elastic element may be formed wave-shaped with at least three bends along the circumferential direction. The elastic element can thereby improve applied to the first friction elements. In addition, an axial spring force can be increased or better controlled.

In a further embodiment, the friction disc clutch further comprises a bolt which extends parallel to the axis of rotation through recesses in the first friction elements. In this case, the elastic element has a recess through which passes bolts. The elastic element can thus be axially displaceable against occurring forces, in particular in the radial direction, secured. The position of the elastic element can thus be ensured even at high speed of the input side.

In yet another embodiment, a projection for engagement in a corresponding recess of a first friction element is attached to a circumferential end of an elastic element. The position of the elastic element with respect to the first friction element can thereby be better secured. In particular, in conjunction with the recess for the bolt, the elastic member may be secured by the projection against twisting around the bolt. A first friction element may have a radially outwardly facing projection for torque-locking engagement with the input side, wherein a width of an elastic element substantially corresponds to the radial length of the projection. The projection usually extends into an axis-parallel slot of the input side, which may be cup-shaped. As a result, the first friction element is mounted in a form-fitting and axially displaceable manner on the input side. The second friction element builds radially shorter, so that in the area axially between projections of two adjacent first friction elements an otherwise unused space is available, in which the elastic element can be arranged. This available space can be exploited improved by the specified width of the elastic element. It is preferable that the elastic member is made of a hardened steel strip. The steel strip can be obtained inexpensively as a semifinished product and further processed by conventional methods. In this case, a plurality of elastic elements can advantageously be made of low-cutting steel tape. For example, the elastic elements can be punched out of the steel strip. After punching, the elastic members can be bent to provide the required preload. By using hardened steel, the spring force of the elastic member can be maintained.

It is further preferred that the material of the elastic element is tempered after curing. Thus, it can be prevented that the elastic element becomes brittle and breaks under load.

It is further preferred that the friction disc clutch is adapted to run in a liquid bath. The liquid bath may in particular be an oil bath. When used in a motorcycle, the friction disc clutch usually runs in the same oil bath as the transmission.

The invention will now be described in more detail with reference to the attached figures, wherein:

FIG. 1 is a sectional view of a friction disc clutch for a motorcycle;

FIG. 2 is another view of the friction disc clutch of FIG. 1;

FIG. 3 shows a side view of a friction disk clutch according to FIGS. 1 or 2 with additional elastic elements;

FIG. 4 shows an elastic element of the friction disk clutch of FIG. 3; and

FIG. 5 shows a plurality of elastic elements in a semifinished product.

Figure 1 shows a sectional view of a friction disc clutch 100, which is preferably adapted for use in a motorcycle. Around an axis of rotation 105, an input side 1 10 and an output side 1 15 are arranged rotatably relative to each other. Also rotatable about the rotation axis 105 are first friction elements 120 and second friction elements 125 axially alternately arranged. The first friction elements 120 are torque-lockingly connected to the input side 1 10 and the second friction elements 125 torque-locking to the output side 1 15. In the present embodiment, a first friction element 120 comprises a radially outwardly facing projection 130, which engages in a recess 135 of the input side 1 10 positively. The recess 135 extends in the axial direction, so that the first friction element 120 is coupled with an axially displaceable torque-locking connection with the input side 110.

In the present embodiment, adjacent second friction elements 125 engage each other in a torque-locking manner, wherein one of the second friction elements 125, in the representation of FIG. 1, the lowermost friction element 125, is positively connected to the output side 15. Other variants are also possible.

For axial compression of the stack of first and mutual friction elements 120, 125, an actuating element 140 is provided. In the present embodiment, the actuating element 140 is designed disc-shaped and radially symmetrical to the axis of rotation 105. The actuating element is mounted axially on a circumference about the axis of rotation 105, which lies radially within the axially abutting friction elements 120 and 125. In this case, the actuating element 140 acts like a plate spring, so that an axial contact pressure of the actuating element 140 on the friction elements 120 and 125 decreases when the actuating element 140 is pressed axially in the direction of the friction elements 120, 125. In order to decouple a rotational movement of the actuating element 140, which is mounted here by way of example with respect to the output side 15, a release bearing 145 can be provided. If the release bearing 145 is moved axially by one release travel, a radially outer region of the activation element 140 is moved axially by one actuation travel. A ratio of Ausrückwegs respect to the actuation path can be selected by selecting appropriate radial leverage ratios. However, other mechanisms for axially compressing the friction members 120, 125 may also be used.

If the actuating element 140 is actuated axially downwards in the representation of FIG. 1 on the release bearing 145, the friction disk clutch 100 opens and a torque lock between the input side 110 and the output side 15 is interrupted. A remaining transmittable torque depends on how well the first and second friction elements 120, 125 are axially lifted apart from each other. In a typical actuation path in the rich of about 2 mm and as shown six first friction elements 120 100 adjacent first friction elements 120 are lifted off from each other on average only by about 1/3 mm with fully open friction disc clutch. In order to ensure that the remaining transmissible torque between the first and the second friction elements 120, 125 is small, it is proposed to insert an elastic element 150 (not shown) between adjacent first friction elements 120 in each case. FIG. 2 shows a further view of the friction disk clutch 100 of FIG. 1. The elastic elements 150 axially between each adjacent first friction elements 120 are not shown here, but only indicated in their positions.

FIG. 3 shows a side view of a friction disk clutch 100 according to one of FIGS. 1 or 2 with additional elastic elements 150. In the upper area, the entire friction disk clutch 100 is shown in FIG. 3a and an enlarged detail in the region of two elastic elements 150 in the lower area in FIG.

The elastic element 150 is preferably designed as a leaf spring and more preferably as a single-ply leaf spring. It is further preferred that between axially adjacent first friction elements 120 at least three elastic elements 150 are distributed on a circumference about the axis of rotation 105. It can also be provided on the circumference more elastic elements 150, in particular as many as recesses 135 are provided in the input side 1 10. The elastic element 150 designed as a leaf spring is stretched in the axial direction and has at least one, but preferably at least three, bends, as shown. As a result, the elastic member 150 is given a waveform in the circumferential direction. Ends of the elastic element 150 and axially outermost points of the bends are applied to the first friction elements 120. It is further preferred that a bolt 305 is provided, which runs parallel to the axis of rotation 105 and are located through recesses in the first friction elements 120 and recesses in the elastic element 150. Preferably, the pin 305 is located in the region of the recesses 135, radially outside an axial abutment region of the first friction elements 120 on the second friction elements 125. An elastic element 150 may have at one of its ends a projection 310 which is adapted to a corresponding recess of a first friction element 120 to intervene. In this case, the end of the elastic element 150 with the projection 310 preferably in the circumferential direction. It is also possible to use projections 310 at be provided the ends. The recess in the first friction member 120 may extend, in particular, in the circumferential direction to allow movement of the projection 310 in the recess in the circumferential direction when the elastic member 150 is axially compressed.

A radial length of a protrusion 130 of a first friction member 120 radially outward of a region in which first and second friction members 120, 125 axially abut one another defines the maximum width of the resilient member 150. Preferably, the width of the resilient member 150 is slightly less than the radial Length of the protrusion 130, in spite of the curvature of the radially outer boundary of the projection 130 of the first friction element 120 about the axis of rotation 105 radially outwardly not overhang.

FIG. 4 shows an elastic element 150 of the friction disk clutch 100 of FIG. 3 in an enlarged view. The waveform along the length of the elastic element 150 formed as a leaf spring, the recesses for receiving the bolt 305 and the projection 310 can be clearly seen.

FIG. 5 shows a plurality of elastic elements 150 in a semifinished product. For example, the elastic members 150 may be formed simply by punching and bending from a sheet. A preferred location of a plurality of elastic members 150 prior to punching in a sheet metal strip 505 is shown in FIG. Along the metal strip 505 a plurality of elastic elements 150 are provided, whose projections 310 preferably point in the same direction. An adjacent row of elastic members 150 in the sheet metal strip 505 has oriented the protrusions 310 in an opposite direction in one embodiment. Recesses for receiving the bolt 305 are preferably made oval, when the elastic element 150 is bent in the region of the recesses.

LIST OF REFERENCE NUMBERS

100 friction disc clutch

105 axis of rotation

1 10 input side

1 15 output side

120 first friction element

125 second friction element

130 advantage

135 recess

140 actuator

145 release bearing

150 elastic element

305 bolts

310 advantage

505 sheet metal strips

Claims

claims

Friction disc clutch (100), comprising:

an input side (110) and an output side (115) arranged coaxially about an axis of rotation (105);

first friction elements (120) which are torque-connected to the input side (1 10);

second friction elements (125) which are torque-connected to the output side (1 15);

wherein first (120) and second friction elements (125) are alternately arranged in the axial direction;

an actuator (140) for axially compressing the friction members (120, 125) to allow torque flow between the input side (110) and the output side (115);

characterized in that

an elastic element (150) is inserted between axially adjacent first friction elements (120) in order to press the friction elements (120) apart axially.

A friction disc clutch (100) according to claim 1, wherein between two axially adjacent first friction elements (120) at least three elastic elements (150) are distributed on a circumference about the axis of rotation (105).

A friction disc clutch (100) according to claim 1 or 2, wherein an elastic member (150) is formed as a single-layered leaf spring.

A friction disc clutch (100) as claimed in any one of the preceding claims, wherein an elastic member (150) is undulated with at least three bends along the circumferential direction.

A friction disc clutch (100) according to any one of the preceding claims, further comprising a bolt (305) extending parallel to the rotation axis (105) through recesses in the first friction members (120), an elastic member (150) having a recess through which the Bolt (305) runs.

A friction disc clutch (100) according to any one of the preceding claims, wherein a projection (310) is mounted on a circumferential end of an elastic member (150) for engagement with a corresponding recess of a first friction member (120).

7. friction disc clutch (100) according to any one of the preceding claims, wherein a first friction member (120) has a radially outwardly facing projection (130) for torque-locking engagement with the input side (1 10) and an elastic member (150) has a width, which substantially corresponds to the radial length of the projection (130).

8. A friction disc clutch (100) according to any one of the preceding claims, wherein an elastic member (150) made of a hardened steel strip can be produced.

The friction disc clutch (100) of claim 8, wherein the material of the elastic member (150) is tempered after curing.

10. A friction disc clutch (100) according to any one of the preceding claims, wherein the friction disc clutch (100) is adapted to run in a liquid bath.