Multi-piston release system for a vehicle brake device, brake device for a vehicle with the multi-piston release system, and gearbox arrangement for a vehicle with the brake device.

Description

[0001] The invention relates to a multi-piston release system for a brake device of a vehicle with the features of the preamble of claim 1, a brake device for a vehicle with the multi-piston release system and a transmission arrangement for a vehicle with the brake device.

[0002] Piston release systems for actuating clutches or brakes in an electric powertrain of a vehicle are well known in the prior art. For example, German patent application DE 10 2020 104 771 A1 describes a slave cylinder for a vehicle release system with a housing that forms a pressure chamber and with a piston that is axially movable within the pressure chamber. To actuate a clutch, the piston can transmit an actuating force to the clutch. Further prior art is disclosed in US patent 3,970,174 A. A multi-piston release system according to the preamble of claim 1 is known from German patent application FR 2,820,794 A1.

[0003] The object of the invention is to provide a functionally improved multi-piston release system for a vehicle's braking system. This object is achieved by a multi-piston release system for a vehicle's braking system with the features of claim 1, by a vehicle's braking system with the multi-piston release system with the features of claim 5, and by a transmission arrangement for a vehicle with the braking system with the features of claim 9. Preferred or advantageous embodiments of the invention are described in the dependent claims, the following description, and the accompanying figures.

[0004] The invention relates to a multi-piston release system designed for integration into a vehicle's braking system. Preferably, the multi-piston release system is designed to actuate a braking device, the braking device being an integral part of the braking system. For example, the braking device is a wet multi-disc service brake, which can be or is arranged within a wet compartment of an electric or hybrid vehicle. Preferably, the multi-disc service brake has a multi-disc assembly with a plurality of friction plates. The wet compartment can be formed by a transmission housing of a transmission assembly for the vehicle. The vehicle is preferably an electric vehicle, in particular an electrically or hybrid-powered passenger car or commercial vehicle.

[0005] The multi-piston release system comprises a ring housing. The ring housing has a main axis that defines an axial direction. The ring housing is arranged concentrically and / or coaxially to the main axis.

[0006] Preferably, the annular housing has at least one flow channel, a fluid inlet, and several pressure chambers, which are fluidically connected to each other via the flow channel. In particular, a fluid, e.g., a hydraulic fluid, can be introduced into the flow channel through the fluid inlet and flow from there into the pressure chambers.

[0007] The annular housing comprises several housing sections, which are preferably arranged spaced apart from one another in the circumferential direction around the annular housing. Each housing section contains a pressure chamber that can be filled with and / or is filled with fluid. In particular, the pressure chamber is incorporated into and / or formed within the housing section.

[0008] The multi-piston release system comprises several hydraulic actuation assemblies. For example, the multi-piston release system includes four, six, or eight actuation assemblies. Each actuation assembly is assigned to exactly one housing section. Preferably, the actuation assemblies are spaced apart from one another in the direction of rotation around the annular housing. It is advantageous that the annular housing and the resulting ring-shaped multi-piston release system can be integrated into the brake assembly and / or the transmission housing in a space-saving manner.

[0009] Each actuating arrangement comprises a piston assembly, wherein the piston assembly includes a hydraulically movable piston. When hydraulically pressurized, the piston can execute an actuating stroke in the axial direction, particularly starting from a neutral position. During the actuating stroke, the piston can generate an actuating force by means of which the braking device can be activated. In particular, during and / or after the execution of the actuating stroke, a pressure force, as the actuating force, can be introduced into a multi-plate clutch assembly of the braking device if the multi-piston release system is integrated into the braking device. The actuating force can cause friction plates of the multi-plate clutch assembly to be pressed together to generate a braking force.

[0010] Preferably, each actuating arrangement comprises a spring assembly which includes a return mechanism. Preferably, the return mechanism is configured to return the piston of the respective actuating arrangement to its initial position. Preferably, the piston performs a return stroke when it is returned by means of the return mechanism.

[0011] The multi-piston release system includes a pressure transmission device. The pressure transmission device is designed and / or arranged to transfer the actuating force transmitted by the piston in an axial direction to and / or introduce it into the lamellar assembly. In particular, the pressure transmission device is operatively connected to the piston for this purpose.

[0012] According to the invention, the actuating force of the piston can be transferred into the annular housing. Preferably, the actuating force can be transferred axially into the annular housing by means of the pressure transmission device. In particular, the actuating force can be transferred into the annular housing in the same direction in which the piston executes its actuating stroke.

[0013] The transfer of the actuating force to the ring housing has the advantage that a force transmission of the multi-piston release system is closed and the actuation of the brake device can take place axially force-free in an installation space surrounding the multi-piston release system, in particular in the wet space formed by the gearbox housing.

[0014] In a preferred embodiment of the invention, the pressure transmission device comprises at least one connecting element, in particular an annular connecting plate or several connecting rods, which are preferably arranged concentrically and / or coaxially to the main axis. Preferably, the actuating force of the piston can be introduced into the connecting element during the axially directed actuating stroke.

[0015] Optionally, the pressure transmission device additionally comprises at least one tensioning device, in particular a tensioning anchor. Preferably, the tensioning device is operatively connected to the connecting device, e.g., pressed to it. Preferably, the tensioning device can be moved into a compression position during the actuation stroke of the piston in order to exert an axially directed compressive force against the friction lamellae of the lamellar assembly in the compression position.

[0016] One possible constructive implementation of the invention provides that the ring housing comprises at least one fastening interface by means of which the ring housing can be attached to an surrounding structure, e.g., the gearbox housing. For example, the at least one fastening interface is formed by several screw devices, which optionally include a hole, a bore, and / or a screw. Preferably, the screw devices are arranged on the ring housing spaced apart from one another in the circumferential direction of the ring housing around the main axis. Preferably, the screw devices are arranged on an inner circumference of the ring housing and / or radially inside. Alternatively, the screw devices are arranged on an outer circumference of the ring housing and / or radially outside.

[0017] In an alternative embodiment of the invention, the at least one fastening interface is formed by a central nut arranged concentrically to the main axis. Preferably, the central nut is connected to the ring housing. In a further alternative embodiment of the invention, the at least one fastening interface is formed by a coaxial and / or concentric retaining ring related to the main axis, which is connected to the ring housing.

[0018] In a preferred embodiment of the invention, each actuating arrangement comprises a retaining plate. Preferably, the retaining plate is mounted axially onto the housing section associated with the respective actuating arrangement. Preferably, the retaining plate is connected to the housing section by a force-fit and / or form-fit connection, for example, by screws.

[0019] In one possible embodiment of the invention, the spring assembly comprises a spring plate, a spring retainer, and a coil spring. Preferably, the spring retainer is positively and / or frictionally connected to the spring plate, in particular by screws. Preferably, the coil spring is arranged between the spring retainer and the mounting plate. In particular, the coil spring is supported at one end by the mounting plate and at the other end by the spring retainer.

[0020] In another possible constructive implementation of the invention, the spring assembly is operatively connected to the piston assembly of the respective actuating arrangement, such that the spring assembly is carried along during the actuating stroke and the return stroke of the corresponding piston. For example, the piston is positively and / or frictionally connected to the spring plate. Preferably, the piston presses against the spring plate when it executes the actuating stroke in the axial direction. This causes the spring plate and the spring plate attached to it to be carried along in the axial direction against the preload of the coil spring.

[0021] When the hydraulic pressure on the piston decreases, the preload of the coil spring returns it to its starting position. In particular, the coil spring serves as a return mechanism.

[0022] In a preferred embodiment of the invention, the at least one connecting element of the pressure transmission device is operatively connected to the piston. For this purpose, the connecting element is operatively connected to the spring plate. For example, the connecting element and the spring plate are positively and / or frictionally connected to one another, e.g., screwed together. In particular, the connecting element can be moved axially together with the spring plate when the piston executes its actuation stroke. Preferably, the connecting element extends, e.g., from the spring plate, in an axially opposite direction, which is particularly contrary to the axial direction. In particular, the connecting element extends axially in the opposite direction through the lamellar assembly of the brake device.The pulling device of the pressure transmission device is preferably arranged at an end of the connecting device directed in the opposite axial direction.

[0023] A braking device for a vehicle with the multi-piston release system according to the foregoing description and / or according to one of claims 1 to 4 constitutes a further object of the invention. The braking device comprises a braking unit for generating a braking force. Preferably, the multi-piston release system forms an actuator for activating the braking unit.

[0024] The braking device comprises a multi-plate assembly with a plurality of friction plates. Preferably, the multi-plate assembly is arranged coaxially and / or concentrically to the main axis. The friction plates consist of inner plates, which are, for example, rotatably arranged, and outer plates, which are, for example, rotationally fixed. Preferably, the inner plates are supported by, for example, a rotatable inner plate carrier. Preferably, the friction plates are arranged and / or designed to be axially movable, in particular displaceable relative to one another.

[0025] In In one possible design embodiment of the invention, the multi-piston release system is arranged axially in front of the brake assembly. Preferably, the lamellar assembly is arranged facing away from the piston.

[0026] InIn a preferred embodiment of the invention, the at least one connecting element of the pressure transmission device of the multi-piston release system extends in the axial opposite direction through the lamellar assembly, in particular through the outer lamellae. Preferably, the pulling element engages at least partially the outermost friction lamella, in particular the outer lamella, arranged in the axial opposite direction and presses against it in the pressure position, so that the friction lamellae are frictionally engaged against each other in the axial direction and can generate the braking force.

[0027] In a further preferred embodiment of the invention, the friction lamellae are supported in the axial direction against the ring housing of the multi-piston release system when they are frictionally engaged against each other in the compression position of the pull device. Preferably, an outermost friction lamella in the axial direction, in particular the outermost lamella, contacts the ring housing in the compression position of the pull device. In particular, this allows the actuating force of the piston to be transmitted to the ring housing via the lamella assembly and the pressure transmission device.

[0028] A further aspect of the invention is a transmission arrangement for a vehicle. The transmission arrangement comprises a transmission housing, a transmission (e.g., a planetary gear), and the braking device according to the preceding description and / or according to one of claims 5 to 8. The transmission and the braking device are housed in the transmission housing. Preferably, the outer plates engage positively in the transmission housing so that they are secured against rotation and are axially movable.

[0029] In one possible practical implementation of the invention, the braking device, in particular the braking assembly, is arranged in the gearbox housing such that it radially surrounds the gearbox with respect to the main axis. Preferably, the inner plates have internal teeth with which they can mesh with a corresponding toothing of a component of the gearbox.

[0030] In one possible practical implementation of the invention, the surrounding structure to which the ring housing of the multi-piston release system is attached via the at least one mounting interface is formed by the transmission housing. Preferably, the actuating force of the piston, which is transmitted to the ring housing, can thereby be transferred into the transmission housing. In particular, the braking torques of the brake system are transferred to the transmission housing when the friction plates bear against the ring housing. The advantage of this is that no additional housing components are required to support a release force of the brake system.

[0031] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These include: Figure 1: A perspective top view of a braking device for a vehicle; Figure 2: A top view in an axial direction of the braking device; Figure 3: A sectional view of the braking device from the Figure 2 along the section line BB; Figure 4 a cross-section of the brake device from the Figure 2 along the section line AA Figure 5 a cross-section of the brake device from the Figure 2 along the CC intersection line.

[0032] Corresponding or identical parts are each provided with the same reference symbols in the figures.

[0033] In the Figure 1Figure 1 shows a perspective top view of a brake device 40 for a vehicle. The brake device 40 can form part of a transmission assembly comprising a transmission housing filled with a wet fluid and a transmission, in particular a planetary gear set. It can be arranged together with the transmission in the transmission housing and generate a braking force there to decelerate at least one component of the transmission. The transmission and the brake device 40 are arranged concentrically and / or coaxially with respect to a principal axis 5 of the brake device 40, the brake device 40 radially surrounding the transmission. The principal axis 5 defines an axial direction 6.

[0034] The Figure 2 The brake device 40 is shown in a top view in the axial direction 6. In conjunction with the Figure 1The brake device 40 includes a brake assembly 41, which is designed as a wet friction disc brake. The brake assembly 41 has a disc pack arrangement 42 with rotatable inner discs 43 and rotationally fixed outer discs 44. The discs 43, 44 are arranged to be movable, in particular displaceable, in the axial direction 6 and in the opposite axial direction. The outer discs 44 can engage positively with a corresponding toothing 45 in the gearbox housing, so that they are axially movable and simultaneously secured against rotation about the main axis 5. The inner discs 43 are arranged on a rotatable inner disc carrier. They have internal teeth 47 with which they can mesh with a corresponding toothing of a gearbox component.During the axial displacement of the lamellae 43, 44, they are frictionally engaged with each other, so that a braking force can be generated to slow down the component of the gearbox.

[0035] The brake device 40 has a multi-piston release system 1, which forms an actuator for actuating the brake device 41 by transmitting and introducing pressure forces as actuating forces. The multi-piston release system 1 is arranged concentrically and / or coaxially with respect to the main axis 5 of the brake device 41. It has an annular housing 2 and several, e.g., six, actuating assemblies 3. The actuating assemblies 3 are arranged on the annular housing 2 in the direction of rotation around the main axis 5 and are partially integrated into it.

[0036] The ring housing 2 comprises several, e.g. six, housing sections 4, each housing section 4 containing a pressure chamber 9 that can be filled and / or is filled with a fluid (see Figures 3 and4 ) is integrated. The pressure chambers 9 in the annular housing 2 are fluidically connected to each other by at least one flow channel integrated into the annular housing 2. The annular housing 2 has a fluid inlet 8 (see Figure 1 ) through which the fluid can be introduced into the flow channel and into the pressure chambers 9. The fluid is different from the wet-space fluid located in the gearbox housing.

[0037] The multi-piston release system 1 can be attached to the gearbox housing by means of several fastening devices 10 designed as screw devices, which are arranged in the direction of rotation around the main axis 5 apart from each other and radially inside the ring housing 2.

[0038] In the Figure 3 is a sectional view of the brake device 40 from the Figure 2The section BB shows the brake assembly 41 and the multi-piston release system 1. The multi-piston release system 1 is arranged in the axial direction 6 in front of the brake assembly 41.

[0039] The outer lamellae 44 and the inner lamellae 43 of the lamellar assembly 42 of the brake device 41 are visible, as are a housing section 4 of the ring housing 2 of the multi-piston release system 1 and an actuating arrangement 3 of the multi-piston release system 1, wherein the actuating arrangement 3 is associated with the housing section 4. The housing section 4 has the pressure chamber 9, which is incorporated into the housing section 4.

[0040] The actuating arrangement 3 comprises a piston assembly 17 with a piston 18, which is screwed to a guide body 7. The piston 18 and the guide body 7 are movably arranged together in the pressure chamber 9 in the axial direction 6, i.e., away from the lamellar assembly 42. During axial movement, the guide body 7 guides the piston 18.

[0041] The actuating arrangement 3 comprises a sliding band seal 19, a further seal 20, and an axial-translational seal 21. The sliding band seal 19 and the further seal 20 are designed as O-rings and are fixedly arranged on the piston 18. They seal the pressure chamber 9 during the movement of the piston 18. The axial-translational seal 21 seals the pressure chamber 9 against the gearbox housing filled with the wet-chain fluid when the brake device 40 is arranged in the gearbox housing.

[0042] The actuating arrangement 3 has a retaining plate 22 which is arranged in the axial direction 6 on the housing section 4 and is screwed to it by means of two screws 23.

[0043] When hydraulically pressurized by the fluid introduced into the pressure chamber 9, the piston 18 can execute an actuating stroke in the axial direction 6 relative to the housing section 4 and the attached retaining plate 22. This actuating stroke moves the piston 18 into an actuating position 11, in which the brake device 41 is actuated.

[0044] The actuating arrangement 3 has a spring assembly 26. The spring assembly 26 comprises a spring plate 27 and two spring plates 28. The spring plate 27 is arranged in the axial direction 6 in front of the retaining plate 22. The spring plates 28 are frustoconical and screwed to the spring plate 27. The spring assembly 26 has two coil springs 29, which are arranged on and surround the spring plates 28. The coil springs 29 are supported at one end by the retaining plate 22 and at the other end by support surfaces of the spring plates 28.

[0045] The piston 18 is positively and / or frictionally connected to the spring plate 27. During the actuation stroke of the piston 18, the spring plate 27, together with the spring plates 28, is moved in the axial direction 6 against a preload of the coil springs 29. The coil springs 29 act as return elements, which return the piston 18 axially in the opposite direction to its initial position when the hydraulic pressure decreases.

[0046] The actuating arrangement 3 has a pressure transmission device 13 for transmitting and introducing the actuating force of the piston 18 into the friction plate assembly 42. The pressure transmission device 13 is shown from different perspectives of the Figures 1 to 5 to be seen. Here the Figure 4 a cross-section of the brake device 40 from the Figure 2 along the intersection line AA and the Figure 5 a cross-section of the brake device 40 from the Figure 2along the CC intersection line.

[0047] The pressure transmission device 13 comprises at least one connecting device 14 arranged concentrically and / or coaxially to the main axis 5, which is designed as several connecting rods. The connecting rods extend from the actuating arrangement 3 in the axial opposite direction to an outermost lamella 46 of the lamella assembly 42 arranged in the axial opposite direction. For this purpose, the connecting rods extend through the lamella assembly 42, in particular through the outer lamellae 44. Each connecting rod is positively and / or force-fitted to a tension device 15 designed as a tie rod, e.g., by a press fit 24. The tension device 15 encompasses the lamella assembly 42, in particular the outermost lamella 46 arranged in the axial opposite direction, at least partially.

[0048] The connecting device 14 is screwed to the spring plate 27 by means of further screws 25. This causes the connecting device 14, together with the spring plate 27, to move in the axial direction 6 when the piston 18 executes its actuating stroke. During the actuating stroke of the piston 18, the tensioning device 15 is carried along by the connecting device 14 and moved in the axial direction 6, so that it assumes a pressure position 12, in which it presses axially against the outermost lamella 46 in the opposite axial direction and frictionally engages the lamellae 43, 44 of the lamella assembly 42.

[0049] The lamellar assembly 42, in particular the lamellar lamellae 43 and 44, are pressed axially 6 against the ring housing 2 in the pressure position 12 of the pull device 15. An outermost lamellar 47, arranged axially 6, contacts the ring housing 2. This allows a disengagement force of the brake device 41 to be supported by the ring housing 2. The actuating force of the piston 18 can be transmitted via the force transmission device 13 and the lamellar assembly 42 into the ring housing 2 and from there into the gearbox housing if the ring housing 2 is attached to the gearbox housing by means of the mounting interfaces 10. Reference symbol list

[0050] 1 Multi-piston release system 2 Ring housing 3 Actuating arrangement 4 Housing section 5 Main axis 6 Axial direction 7 Guide body 8 Fluid inlet 9 Pressure chamber 10 Mounting interfaces 11 Actuating position 12 Pressure position 13 Pressure transmission device 14 Connecting device 15 Pulling device 16 Not assigned 17 Piston assembly 18 Piston 19 Sliding band seal 20 Additional seal 21 Axially translational seal 22 Retaining plate 23 Screws 24 Press fit 25 Additional screws 26 Spring assembly 27 Spring plate 28 Spring plate 29 Coil springs 40 Brake device 41 Brake device 42 Clutch assembly 43 Inner clutch plates 44 Outer clutch plates 45 Outer teeth 46 Outermost clutch plate in axial opposite direction 47 Inner teeth 48 axial direction outermost outer lamella

Claims

1. A multi-piston disengagement system (1) for a brake device (40) of a vehicle, having an annular housing (2), the annular housing (2) having a main axis (5), the main axis (5) defining an axial direction (6), the annular housing (2) comprising a plurality of housing sections (4), a pressure chamber (9) which can be and / or is filled with a fluid being arranged in each housing section (4), having a plurality of hydraulic actuating arrangements (3), each actuating arrangement (3) being assigned a housing section (4), each actuating arrangement (3) comprising a piston assembly (17) with a hydraulically movable piston (18), the piston (18) being able to execute an actuating stroke in the axial direction (6) when subjected to hydraulic pressure and being able to generate an actuating force for activating a brake device (41) of the brake device (40), characterised in that the actuating force can be diverted into the annular housing (2).

2. The multi-piston disengagement system (1) according to claim 1, characterised in that the multi-piston disengagement system (1) comprises a pressure transmission device (13) for transmitting and / or introducing the actuating force to / into a disk pack arrangement (42) of the brake device (41), the pressure transmission device (13) comprising at least one connecting device (14) and a pulling device (15) operatively connected to the connecting device (14), wherein the actuating force of the piston (18) can be introduced into the connecting device (14) in the axial direction (6), and wherein the at least one pulling device (15) can be transferred into a pressure position (12) for exerting an axially directed pressure force against the disk pack arrangement (42) of the brake device (41) during the actuating stroke of the piston (18).

3. The multi-piston disengagement system (1) according to claim 1 or 2, characterised in that the annular housing (2) has at least one fastening interface (10) for fastening the annular housing (2) to a surrounding structure.

4. The multi-piston disengagement system (1) according to claim 3, characterised in that the at least one fastening interface is formed by a plurality of screw devices, the screw devices being arranged on the annular housing (2) at a distance from one another in the circumferential direction of the annular housing (2) about the main axis (5), the screw devices being arranged on an inner circumference or on an outer circumference of the annular housing (2).

5. A brake device (40) for a transmission arrangement of a vehicle with the multi-piston disengagement system (1) according to any one of the preceding claims and having a brake device, the brake device (41) having a disk pack arrangement (42) with a plurality of friction disks (43, 44).

6. The brake device (40) according to claim 5, characterised in that the multi-piston disengagement system (1) is arranged in the axial direction (6) upstream of the brake device (41).

7. The brake device (10) according to claim 5 or 6, characterised in that the at least one connecting device (14) of the pressure transmission device (3) extends in an axially opposite direction through the disk pack arrangement (42), the at least one pulling device (15) of the pressure transmission device (3) engaging around the disk pack arrangement (42) at least in sections and, in the pressure position (12), exerting a compressive force against the friction disks (43, 44) of the disk pack arrangement (42).

8. The brake device (40) according to one of claims 5 to 7, characterized in that the friction plates (43, 44) are frictionally engaged with one another in the pressure position (12) of the at least one pulling device (15) and are supported on the annular housing (2) in the axial direction (6).

9. A transmission arrangement for a vehicle, characterised in that the transmission arrangement comprises a transmission housing, a transmission and the brake device (40) according to one of claims 5 to 7, the transmission and the brake device (40) being accommodated in the transmission housing.

10. The transmission arrangement according to claim 9, characterised in that the surrounding structure, to which the annular housing (2) of the multi-piston disengagement system (1) is fastened by means of the at least one fastening interface (10), is formed by the transmission housing.