Wet multi-plate clutch or brake and vehicle

Abstract

The invention relates to a wet-running multi-plate clutch or brake for the drive train of a vehicle, comprising a plate pack with inner plates (1) and outer plates (2), an inner plate carrier on which the inner plates (1) are arranged in a rotationally fixed but axially displaceable manner, and an outer plate carrier (3) on which the outer plates (2) are arranged in a rotationally fixed but axially displaceable manner. The plate pack can be compressed axially by means of an actuating piston in order to produce a frictional connection between the inner plates (1) and outer plates (2) for transmitting a rotary movement between the inner plate carrier and the outer plate carrier (3). The wet-running multi-plate clutch or brake is characterized in that the plate pack terminates on a side opposite the actuating piston with an axially two-part end outer plate (2E), wherein in at least one of the two halves (2E.1, 2E.2) the end outer plate (2E) has two radially circumferential grooves (4, 4i, 4a) on a side (S) facing the other half (2E.2, 2E.1), into each of which an elastomer ring (5) is inserted, wherein a respective groove cross-section and a respective elastomer ring cross-section are adapted to one another such that the respective elastomer ring (5) partially protrudes from the respective groove (4, 4i, 4a) in an unloaded state, and wherein a radial distance (r1) of the inner circumference (6) to a groove (4i) lying on the inside in the radial direction and a radial distance (r2) of the outer circumference (7) to a groove (4a) lying on the outside in the radial direction are the same.

Description

[0001] The invention relates to a wet-running multi-disk clutch or brake for the drive train of a vehicle according to the type defined in more detail in the preamble of claim 1 and to a vehicle with such a wet-running multi-disk clutch or brake.

[0002] Wet multi-plate clutches or brakes have proven themselves for many years in vehicle use.

[0003] Two types of vibration problems can generally occur during operation of wet-running multi-plate clutches or brakes. Firstly, these are tribologically induced vibrations due to unfavorable friction values, particularly when the multi-plate clutch is new, or due to unfavorable friction characteristics and aging due to additives such as friction reducers added to the medium surrounding the plates. Secondly, these are geometrically induced vibrations during the pressing of the outer and inner plates together in the slip phase during clutch engagement due to uneven friction partners. The resulting starting pulsations are also attributed to so-called torque uniformity (MGF) or torque oscillation, also known as "torque oscillation." The invention addresses the problem of geometrically induced vibration excitation.

[0004] To counteract the negative effects of MGF and / or torque oscillation, i.e., the aforementioned starting pulsations, various measures are known, although they have their drawbacks. Firstly, measures are taken to prevent the occurrence of the aforementioned starting pulsations. For this purpose, particularly tight tolerance limits can be selected for the flatness of the respective friction partners, but this leads to high manufacturing costs and a high labor intensity. Furthermore, only geometrically matching component pairs can be installed. For example, all lamellae can be laser-measured and precisely assembled before installation, although this also entails increased manufacturing effort and corresponding costs.

[0005] Alternatively, corresponding starting pulsations can be compensated for using a separate disc spring. However, this is a complex additional component. The development and production of such disc springs, especially depending on different operating conditions, also increases the effort and cost of manufacturing the multi-disk clutch or brake.

[0006] DE 10 2013 015 385 A1 discloses a multi-plate clutch in which a spring device consists of several disc springs of smaller diameter arranged around the circumference of two immediately adjacent friction rings.

[0007] DE 692 07 328 T2 discloses a clutch with friction discs in which a progressivity device is provided which has a corrugated ring or a radially oriented elastic metal plate.

[0008] US 2008 / 0 217 133 A1 discloses a wet-type multi-disk friction clutch device, wherein a recess is provided in a support plate arranged at a position opposite a piston, into which recess a projection element is fitted.

[0009] DE 10 2021 210 240 A1 discloses a clearance adjustment for wet-running multi-plate clutches or brakes in a drive train of electrically powered vehicles. The document describes a multi-plate clutch or brake in which the respective outer or inner plates support each other via annular elastic elements when the plate pack is compressed. After the contact pressure is removed, these elastic elements cause the outer and inner plates to detach from each other, thus preventing the plates from sticking to each other due to the capillary action of thin oil films between the plates. However, this arrangement of plates and elastic elements disclosed in the document is completely unsuitable for compensating MGF or torque oscillation.

[0010] The present invention is based on the object of providing an improved wet-running multi-disk clutch or brake characterized by an increased ability to compensate for MGF and / or torque oscillations or the associated starting pulsations. Furthermore, the wet-running multi-disk clutch or brake should be cost-effective to manufacture.

[0011] According to the invention, this object is achieved by a wet-running multi-disk clutch or brake having the features of claim 1. Advantageous embodiments and further developments as well as a vehicle comprising such a wet-running multi-disk clutch or brake emerge from the dependent claims.

[0012] A generic wet-running multi-plate clutch or brake for the drive train of a vehicle, comprising a plate pack with inner plates and outer plates, an inner plate carrier on which the inner plates are arranged in a rotationally fixed but axially displaceable manner, an outer plate carrier on which the outer plates are arranged in a rotationally fixed but axially displaceable manner, wherein the plate pack can be axially compressed by means of an actuating piston in order to produce a frictional connection between the inner plates and outer plates for transmitting a rotational movement between the inner plate carrier and the outer plate carrier, is further developed according to the invention in that the plate pack terminates on the side opposite the actuating piston with an axially split end outer plate, wherein in at least one of the two halves of the end outer plate, on a side facing the other half, at least one groove, in particular a radially circumferential groove,is introduced into which an elastomer ring is inserted, wherein a groove cross-section and an elastomer ring cross-section are adapted to one another in such a way that the elastomer ring partially protrudes from the groove in an unloaded state.

[0013] The invention is based on the following idea: When starting up, i.e. when the plate pack is pressed together, the individual inner and outer plates begin to contact one another and transmit a frictional force acting in the circumferential direction. Initially, there is still a speed difference between the outer and inner plates, i.e. slippage. The actuating piston exerts a comparatively small axial contact force on the plate pack. The axial force of the actuating piston is successively increased or the actuating piston moves further towards the plate pack so that all inner plates touch their respective adjacent outer plates. Due to the arrangement of the end outer plate at the end of the plate pack opposite the actuating piston, the two halves of the end outer plates are ultimately supported on one another via the elastomer ring. In this state, the elastomer ring acts as an elastic vibration damper to absorb force and vibration.Movement pulsations in an axial direction. In other words, the entire disk pack is clamped axially with minimal elasticity. This compensates for the aforementioned starting pulsations caused by torque uniformity or torque oscillation.

[0014] By supporting the two halves of the end outer plate on each other via at least one elastomer ring, slight wobbling movements of the two halves of the end outer plate relative to each other are made possible and axial pulsations can be absorbed by the individual friction surfaces without these pulsations being reflected outwards as torque increases.

[0015] Elastomer rings are inexpensive and widely available. The incorporation of grooves into corresponding components is also simple and cost-effective. This allows the wet-running multi-disk clutch or brake according to the invention to be manufactured cost-effectively and without significant effort. This provides a simple and cost-effective solution for compensating for starting pulsations. The wide availability of a wide variety of elastomer rings ensures quick and easy replacement during maintenance.

[0016] The desired spring effect of the elastomer ring can also be adjusted using material parameters of the elastomer ring material, i.e. in particular depending on the modulus of elasticity and the shear modulus of the material.

[0017] According to the invention, at least one pair consisting of a groove and an elastomer ring is provided. However, the wet-running multi-plate clutch or brake according to the invention can also have several pairs of corresponding grooves and elastomer rings. An elastomer ring is provided for each groove. The geometry of the individual grooves and elastomer rings can be the same or can be designed differently for different pairs of groove and elastomer ring. In addition, all pairs of groove and elastomer ring can be incorporated in exactly one of the two halves of the end outer plate, or some pairs of groove and elastomer ring can be provided in one half of the end outer plate and other pairs of groove and elastomer ring in the other half of the end outer plate.

[0018] Particularly when elastomer rings of different thicknesses are provided, the number of corresponding support surfaces can be successively increased during the pressing of the plate pack. This way, the two halves of the final outer plate first rest on the thicker elastomer ring and then, during further pressing, also on the other, thinner elastomer ring. This allows the vibration behavior of the wet-running multi-plate clutch or brake to be specifically influenced depending on a specific operating point.

[0019] All common elastomers can be used to form the elastomer ring. The selection of the appropriate material can be determined depending on the application scenario and the vibration behavior of the wet-running multi-disk clutch or brake according to the invention.

[0020] Friction linings can be arranged on one or both sides of the inner and outer plates. The disc pack can therefore be single-sided or double-sided. The friction linings can take on all common shapes, for example, as a flat, unslotted circular ring.

[0021] An advantageous development of the wet-running multi-plate clutch or brake according to the invention further provides that the elastomer ring has a circular cross-section whose radius is greater than the depth of the groove. In general, the elastomer ring can have any cross-sectional shape, such as a rectangular, square, or oval cross-sectional shape. However, elastomer rings with a circular cross-section are characterized by their symmetry and simplicity. As the plate pack is progressively pressed together, a contact point or, viewed in the circumferential direction, a contact line is initially established between one half of the end outer plate and the elastomer ring. As the two halves of the end outer plates move further towards one another, the contact area then continuously increases due to the compression of the elastomer ring.This behavior can improve the compensation capability to reduce the negative influence of corresponding starting pulsations. The protrusion of the elastomer ring from the groove is particularly easy to achieve by selecting an elastomer ring with a radius larger than the groove depth.

[0022] According to a further advantageous embodiment of the wet-running multi-plate clutch or brake according to the invention, the elastomer ring is designed as an O-ring. O-rings are inexpensive and widely available. This further reduces the effort and costs involved in designing the wet-running multi-plate clutch or brake according to the invention. In particular, since it is a standard component available in countless geometric and material variants, it is ensured that a suitable O-ring can be found for the most diverse application scenarios of the wet-running multi-plate clutch or brake.

[0023] The O-ring is used for a different purpose and is not used to seal a gap, but to absorb vibrations.

[0024] A further component of the present invention is therefore the use of at least one O-ring to compensate for MGF and / or torque oscillation and the resulting starting pulsations when engaging the disk pack of a wet-running multi-disk clutch or brake.

[0025] A further advantageous embodiment of the wet-running multi-disk clutch or brake according to the invention further provides that the groove cross-section, the elastomer ring cross-section, and the material characteristics of the elastomer ring are coordinated such that when a defined blocking force is exerted on the disk pack by means of the actuating piston, the elastomer ring can be completely accommodated by the groove. At the end of the starting process, i.e., when the wet-running multi-disk clutch or brake according to the invention transitions to the engaged state, a frictional connection exists between all outer and inner disks of the disk pack. The outer disk carrier and the inner disk carrier then rotate at the same speed.To make this easier, the two halves of the end outer plate are moved towards each other until they lie flat on the side facing the other half of the end outer plate. To do this, the elastomer ring must be pressed completely into the groove. The groove cross-section is therefore slightly larger so that the elastomer ring can be completely accommodated in the groove. The material characteristics of the elastomer ring are selected so that the elastomer ring only disappears into the groove when the specified opening force is reached. If the elastomer ring is softer, it can be pressed into the groove more easily because the elastomer ring deforms more quickly and can therefore adapt to the geometry of the groove cross-section. This type of elastomer ring is therefore suitable for lower opening forces. If, on the other hand, the elastomer ring is harder orless elastic, a higher contact pressure is required to press the elastomer ring into the groove.

[0026] According to a further advantageous embodiment of the wet-running multi-plate clutch or brake according to the invention, the elastomer ring protrudes from the groove by a maximum of 0.3 millimeters in the unloaded state. The extent to which the respective elastomer ring protrudes from the groove is available as spring travel to compensate for starting pulsations. A spring travel of a maximum of 0.3 millimeters has proven to be particularly beneficial for the compensation behavior of the wet-running multi-plate clutch or brake according to the invention.

[0027] A further advantageous embodiment of the wet-running multi-disk clutch or brake according to the invention further provides that, when providing exactly one groove, the groove is radially centered between the inner circumference and the outer circumference in the respective half of the end outer plate. This ensures symmetrical support of the two halves of the end outer plate. This further promotes the compensation effect.

[0028] According to a further advantageous embodiment of the wet-running multi-plate clutch or brake according to the invention, when two or more grooves are provided, the radial groove spacing between the respective grooves is equal, wherein, in particular, the radial distance from the inner circumference to the groove located furthest inside in the radial direction and the radial distance from the outer circumference to the groove located furthest outside in the radial direction are also equal to the radial groove spacing. This also ensures symmetrical support of the two halves of the end outer plate when more than one pair of groove and elastomer ring is provided.

[0029] A further advantageous embodiment of the wet-running multi-plate clutch or brake according to the invention further provides that the two halves of the end outer plate are each free of friction linings, at least on the side facing the other half. This allows the two halves of the end outer plate to be manufactured even more cost-effectively and easily. Furthermore, less installation space is required in the axial direction to accommodate the plate pack. The two halves of the end outer plate can also be free of friction linings on the sides facing away from each other.

[0030] According to a further advantageous embodiment of the wet-running multi-plate clutch or brake according to the invention, at least one of the two halves of the end outer plate comprises steel or consists entirely of steel. Both halves of the end outer plate can also comprise or consist of the same material. Steel has proven to be a suitable material for forming plates of multi-plate clutches or brakes. To manufacture the end outer plate, two standard outer plates can be provided, with one of these outer plates forming the half of the end outer plate that does not have a groove, and the groove for receiving the elastomer ring being introduced into the corresponding other outer plate to form the second half of the end outer plate.

[0031] The two halves of the end outer lamella can have the same strength or thickness in the axial direction or can be of different thicknesses.

[0032] According to the invention, a vehicle has at least one wet multi-plate clutch or brake as described above. The vehicle can generally also comprise several such wet multi-plate clutches and / or brakes. The vehicle is preferably a road vehicle such as a car, truck, van, bus, or the like. The vehicle can have an internal combustion engine and / or an electric motor used as the prime mover. It can therefore also be a hybrid vehicle or a vehicle powered purely by battery-electric power or by a fuel cell system. The integration of the wet multi-plate clutch or brake according to the invention also makes it possible to reduce the manufacturing costs of the vehicle.

[0033] Further advantageous embodiments of the wet-running multi-disk clutch or brake according to the invention also result from the exemplary embodiments which are described in more detail below with reference to the figures.

[0034] Showing: Fig. 1 is a schematic sectional view showing a contact area of ​​two halves of an end outer plate of a wet-running multi-plate clutch or brake according to the invention during and after the engagement process; Fig. 2 a detailed view of the Fig. 1 shown contact area; Fig. 3 a schematic plan view in the axial direction of that half of the end outer plate in which a groove for receiving an elastomer ring is introduced; Fig. 4 is a schematic plan view in the axial direction of an alternatively designed half of the end outer plate, comprising two grooves; and Fig. 5 a schematic sectional view through the two halves of the end outer plate according to a further alternative embodiment, in which a groove for receiving an elastomer ring is introduced into each of the two halves.

[0035] When engaging wet multi-plate clutches or brakes, geometrically induced vibration problems can occur. If the force applied axially to the plate pack of the wet multi-plate clutch or brake by an actuating piston (not shown in detail in the figures) is so small that the respective inner plates 1 and outer plates 2 rub against each other with slippage, vibrations can occur during this slip phase due to uneven friction partners. A wet multi-plate clutch or brake according to the invention comprises corresponding means for compensating for such starting pulsations.

[0036] Fig. 1 shows a section of the wet-running multi-disk clutch or brake according to the invention at two different times during engagement. Fig. 1a) the disk pack is subjected to a contact pressure F by means of the actuating piston. ax 1, so that the respective inner plates 1 and outer plates 2 rub against each other with slippage. Also shown is an outer plate carrier 3, to which the outer plates 2 are attached in an axially displaceable but rotationally fixed manner. The respective friction linings are provided with the reference numeral 8. The friction linings 8 can be attached to both the inner plates 1 and the outer plates 2. They can be so-called single-sided or double-sided plate packs. The number of friction surfaces is not limited.

[0037] Fig. 1b) shows the fully compressed state of the inner plates 1 and outer plates 2, creating a frictional connection between the respective friction partners. For this purpose, a so-called open-blocking force F is applied to the plate pack by means of the actuating piston. ax 2. The block pressing force F ax 2 is greater than the contact force F ax 1, which in Fig. 1b) is indicated by a thicker arrow.

[0038] According to the invention, the plate pack terminates on the side opposite the actuating piston with an axially two-part end outer plate 2E, wherein in at least one of the two halves 2E.1, 2E.2, here half 2E.1, at least one groove 4 is introduced on the side S facing the other half 2E.2, into which groove an elastomer ring 5 is inserted, wherein the groove cross-section and the elastomer ring cross-section are adapted to one another in such a way that the elastomer ring 5 partially protrudes from the groove 4 in the unloaded state.

[0039] In Fig. 1a) the contact force F ax 1 is just large enough for half 2E.2 of the end outer plate 2E to just rest on the elastomer ring 5. This provides a spring travel f that can be used to dampen the corresponding starting pulsations.

[0040] In Fig. 1b), however, the plate pack is pressed into a block, so that the elastomer ring 5 disappears completely into the groove 4. The two halves 2E.1 and 2E.2 then lie flat against one another via the side SG facing the other half 2E.2, 2E.1. At correspondingly high axial forces, the starting pulsations have only a negligible influence on the engagement quality of the wet-running multi-plate clutch or brake according to the invention, so that an elastic support effect via the elastomer ring 5 is no longer required. This now enables the comparatively high axial forces to be transmitted across the entire plate surface.

[0041] The two halves 2E.1 and 2E.2 of the end outer lamella 2E can have the same or different thicknesses d 1 , d 2 in the axial direction. In addition, the two halves 2E.1, 2E.2, particularly on the sides SG, are free of friction linings 8.

[0042] Fig. Figure 2 shows the contact area in the unloaded state of the plate pack in detail. For example, the elastomer ring 5 has a circular cross-section. Particularly preferably, the elastomer ring 5 is formed by an O-ring. The groove 4 is geometrically adapted to the cross-sectional shape of the elastomer ring 5 and the corresponding material parameters of the material used to form the elastomer ring 5, so that sufficient space is available to accommodate the elastomer ring 5 when the plate pack is pressed into a block. In the figures, the groove 4 is approximately elliptical for this purpose.

[0043] Particularly preferably, the spring travel f is a maximum of 0.3 millimeters. This has proven to be particularly favorable for the compensation behavior of the wet-running multi-disk clutch or brake according to the invention. Fig. 2, no force is exerted on the disk pack by means of the actuating piston, so that the two halves 2E.1 and 2E.2 of the end outer disk 2E are axially spaced from each other.

[0044] Fig. 3 shows an axial plan view of that half 2E.1 of the end outer plate 2E into which the groove 4 is introduced. Preferably, the groove 4 is introduced radially centrally between the inner circumference 6 and the outer circumference 7 of the respective half 2E.1.

[0045] Fig. Figure 4 shows a further alternative embodiment in which two grooves 4a and 4i are incorporated into half 2E.1. Particularly preferably, the respective radial distances r1, Δr, and r2 between the respective inner circumference 6, the grooves 4i, 4a, and the outer circumference 7 are equal. This ensures a symmetrical supporting effect. In general, however, the radial groove distance Δr could also differ from the radial distance r1 or r2.

[0046] Fig.5 shows an alternative embodiment of the end outer plate 2E, in which exactly one groove 4 with a respective elastomer ring 5 is provided in each of the two halves 2E.1 and 2.E2.

[0047] The wet-running multi-disk clutch or brake according to the invention can be manufactured cost-effectively, the spring effect of the elastomer ring 5 can be adapted to the respective application conditions by means of a suitable geometry and choice of material, and standard components such as O-rings can be used, which allows cost-effective and simple production as well as easy replacement in the event of maintenance.

Claims

[1] Wet-running multi-plate clutch or brake for a drive train of a vehicle, comprising a plate pack with inner plates (1) and outer plates (2), an inner plate carrier on which the inner plates (1) are arranged in a rotationally fixed but axially displaceable manner, an outer plate carrier (3) on which the outer plates (2) are arranged in a rotationally fixed but axially displaceable manner, wherein the plate pack can be compressed axially by means of an actuating piston in order to effect a frictional connection between the inner plates (1) and outer plates (2) for transmitting a rotary movement between the inner plate carrier and the outer plate carrier (3), where the plate pack terminates on a side opposite the actuating piston in the axial direction with an axially two-part end outer plate (2E), wherein in at least one of the two halves (2E.1, 2E.2) of the end outer plate (2E) on a side (S) facing the other half (2E.2, 2E.1) two radially circumferential grooves (4i, 4a) are introduced, into each of which an elastomer ring (5) is inserted, wherein a respective groove cross-section and a respective elastomer ring cross-section are adapted to one another such that the respective elastomer ring (5) partially protrudes from the respective groove (4i, 4a) in an unloaded state, and wherein a radial distance (r1) of the inner circumference (6) to a groove (4i) located on the inside in the radial direction and a radial distance (r2) of the outer circumference (7) to a groove (4a) located on the outside in the radial direction are the same. [2] Wet-running multi-disk clutch or brake according to claim 1, characterized by , that the elastomer ring (5) has a circular cross-section whose radius is greater than a groove depth. [3] Wet-running multi-disk clutch or brake according to claim 2, characterized by that the elastomer ring (5) is formed by an O-ring. [4] Wet-running multi-disk clutch or brake according to one of claims 1 to 3, characterized by that the groove cross-section, the elastomer ring cross-section and material parameters of a material from which the elastomer ring (5) is made are matched to one another in such a way that when a fixed open-block pressing force (F ax 2) is exerted on the disk pack, the elastomer ring (5) can be completely received by the groove (4i, 4a). [5] Wet-running multi-disk clutch or brake according to one of claims 1 to 4, characterized by that the elastomer ring (5) protrudes a maximum of 0.3 millimetres from the groove (4i, 4a) in the unloaded state. [6] Wet-running multi-disk clutch or brake according to one of claims 1 to 5, characterized by that the two halves (2E.1, 2E.2) of the end outer plate (2E) are each free of friction linings (8) at least on the side (SG) facing the respective other half (2E.2, 2E.1). [7] Wet-running multi-disk clutch or brake according to one of claims 1 to 6, characterized by that at least one of the two halves (2E.1, 2E.2) of the end outer plate (2E) comprises steel or consists entirely of steel. [8] Vehicle, characterized by at least one wet-running multi-disk clutch or brake according to one of claims 1 to 7.

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