Multiple-disc brake

Abstract

The invention relates to a multiple-disc brake having a brake disc set with at least one inner disc and at least one outer disc, wherein the inner disc and the outer disc are arranged axially, and wherein at least one of the at least one inner disc and / or the at least one outer disc has a friction lining, and a brake actuator which is arranged on the brake disc set for actuating the brake disc set, wherein the brake actuator has an axially displaceable actuating element for actuating the brake disc set, and a counterholder is provided on the opposite side of the brake disc set, wherein the counterholder is arranged adjacent to the brake disc set on the side opposite the actuating element in relation to the disc set. The actuating element and / or the counterholder bears against a friction lining of at least one of the at least one inner disc and / or at least one outer disc such that, in the event that the multiple-disc brake is activated, the counterholder and / or the actuating element acts directly on the friction lining of at least one of the inner and / or outer discs.

Description

[0001] MULTI-CLASS BRAKE

[0002] The invention relates to a multi-plate brake with a brake plate assembly comprising at least one inner plate and at least one outer plate, wherein the inner and outer plates are arranged axially and wherein at least one of the at least one inner plate and / or the at least one outer plate has a friction lining and a brake actuator arranged on the brake plate assembly for actuating the brake plate assembly, wherein the brake actuator has an axially displaceable actuating element for actuating the brake plate assembly, and a counterholder is provided on the opposite side of the brake plate assembly, wherein the counterholder is arranged adjacent to the brake plate assembly on the side opposite the actuating element with respect to the plate assembly.

[0003] Various designs of multi-disc brakes are known from the prior art. A multi-disc brake system is known from EP108024A2. Published patent DE69222883T2 also discloses a special multi-disc brake system in which the brake is normally closed by preload. A particular embodiment is known, for example, from AT520430A4. This discloses a multi-disc brake system that is encapsulated in a housing. Such a brake system is particularly interesting for electric vehicles and especially for preventing the emission of brake dust. Various systems for actuating such a brake exist in the prior art.

[0004] It is an object of the present invention to develop a particularly efficient actuation system in connection with a multi-disc brake. This system should be designed to be particularly efficient, space-saving, and cost-effective. Therefore, one of the objects of the invention is to further develop a multi-disc brake according to the preamble of claim 1. This object is achieved according to the characterizing part of claim 1.

[0005] By having the actuating element and / or the counter-holder rest against a friction lining of at least one of the at least one inner and / or at least one outer lamellae, so that in the event of activation of the multi-disc brake the counter-holder and / or the actuating element acts directly on the friction lining of at least one of the inner and / or outer lamellae and, in particular, contacts and / or brakes it, the axial installation space of the multi-disc brake can be reduced. Furthermore, for example, steel lamellae or other parts that are usually arranged between the actuating element and the friction lamella on the one hand and / or the counter-holder and the friction lamella on the other hand can be eliminated.

[0006] This further reduces the number of rotating parts and the mass of the multi-disc brake. This also reduces the inertia of the multi-disc brake and allows for a faster response time. Additionally, this new design also results in cost savings.

[0007] The fact that the actuating element and / or the counter-holder are at least partially made of a sintered material offers particular advantages. Besides advantages in flexible shaping, sintered materials are characterized by special damping properties. Furthermore, sintering processes allow the production of workpieces from various metallic and, in some cases, non-metallic elements, which cannot be produced by other methods, such as casting and / or plating, or only to an insufficient degree. The lower density of sintered materials compared to workpieces produced by other bulk forming or shaping processes proves to be a significant advantage in moving tools / workpieces, allowing for weight savings and faster-reacting systems. Moreover, the porosity of sintered materials proves to be particularly advantageous in the present invention.The porosity of sintered materials allows for targeted oil absorption at the contact surface with the friction lining. Sintered materials typically have open pores on their surface, which act as oil pockets. This results in improvements in cooling, wear resistance, and emergency running properties.

[0008] Depending on the embodiment, it may also be necessary to rework the surface of the actuating element and / or the counterholder, which consists at least partially of a sintered material, in particular mechanically, for example by grinding and / or brushing.

[0009] According to a particular embodiment, the actuating element and / or the counterholder is composed of several materials and / or workpieces, wherein at least one part of it comprises a sintered material.

[0010] The multi-disc brake can be actuated hydraulically, pneumatically, or via a transmission, in particular an electric transmission, with a suitable gear ratio. According to a particular embodiment, both the actuating element and the counter-holder are in contact with the friction lining of at least one of the at least one inner and / or at least one outer disc, so that when the multi-disc brake is activated, the counter-holder and the actuating element act directly on the friction lining of at least one of the inner and / or outer discs, in particular contacting and / or braking them.

[0011] In a particular embodiment, the lamellar assembly is subjected to pressure from both sides in a pliers-like movement. This allows for an ideal force transmission between the two pliers in the axial direction, which is particularly advantageous from a mechanical engineering perspective and with regard to the dynamics of the brake.

[0012] According to a particular embodiment, the actuating element and / or the counter-holder, which rests against the friction lining, has at least a partially sintered material structure, particularly in the area where contact with the friction lining is present.

[0013] The sintered surface allows for a unique surface roughness profile. Roughness peaks are flattened. This results in particularly efficient and advantageous break-in behavior of the multi-disc brake and favorable wear characteristics. Furthermore, the special surface structure with targeted micro-spaces for lubricant retention ensures optimal lubrication and heat dissipation. Sintering processes also enable the creation of special material combinations characterized by exceptional thermal conductivity and resistance.

[0014] According to a particular embodiment, an activation mechanism for relocating the actuating element is provided, which, depending on the embodiment, is electrical and / or mechanical and / or hydraulic and / or pneumatic. According to a particular embodiment, the activation mechanism is arranged radially outside the clutch pack such that at least part of the activation mechanism radially covers the clutch pack. The chosen design according to the invention enables a particularly space-saving construction. In particular, the important axial length of the multi-disc brake can be reduced in this way.

[0015] According to a particular embodiment of the invention, the brake actuator arranged on the brake plate assembly is equipped for actuating the brake plate assembly with a ball ramp comprising a first ball ramp body and a second ball ramp body and at least one ball arranged between the first and the second ball ramp body, wherein the first and / or the second ball ramp body has at least one track on its surface with at least partially varying depth, along which the at least one ball is movable, wherein the first ball ramp body is arranged on a first side, via which at least one ball is connected to the second ball ramp body in such a way that it is axially movable by rotating the first and / or second ball ramp body, and the first ball ramp body is arranged adjacent to the brake plate assembly and is configured as the actuating element for directly actuating the brake plate assembly.

[0016] Because the back of at least part of the first or second ball ramp body rests against the friction lining of one of the at least one inner lamella or one of the at least one outer lamellae, a particularly compact and efficient design of a multi-disc brake is possible.

[0017] According to a particular embodiment of the invention, the first ball ramp body, which rests against the friction lining, has at least partially a sintered material structure on its contact surface with the friction lining.

[0018] According to a particular embodiment of the lamellar brake according to the invention, the first or second ball ramp body, which bears against the friction lining, has a sintered material structure. This manufacturing process allows the surface of the ball ramp body, which bears against the friction lining, to be designed with a specific composition and / or structure, for example, porosity.

[0019] According to a particular embodiment of the multi-plate brake according to the invention, the first or second ball ramp body, which bears against the friction lining, is cup-shaped and / or formed such that a portion of the ball ramp body projecting radially beyond the brake plate assembly is axially recessed or projecting forward, so that at least a portion of the brake plate assembly is radially covered by the ball ramp body. This saves further valuable installation space, particularly in the axial direction.

[0020] In a particular embodiment of the multi-disc brake according to the invention, the at least one ball of the ball ramp is arranged radially on the outside of the brake disc assembly and at least partially covers it. This measure allows for further savings of valuable installation space.

[0021] According to a particular embodiment of the lamellar brake according to the invention, the first and / or second ball ramp body has a recess for a bearing seat.

[0022] According to a particular embodiment of the lamellar brake according to the invention, the ball ramp can be actuated via an electric motor, so that the first and / or the second ball ramp body can be rotated via the electric motor.

[0023] According to a particular embodiment of the lamellar brake according to the invention, a sealed housing is provided and the brake lamellar package is arranged in the housing in such a way that no particles of the friction linings of the brake lamellar package can escape unhindered from the interior of the housing into the environment.

[0024] According to a particular embodiment of the lamellar brake according to the invention, a supply of coolant for cooling the brake lamellar package is provided in the housing.

[0025] The invention is illustrated in the following schematic figures using non-restrictive embodiments. They show:

[0026] Fig. 1 shows an exemplary brake disc assembly in oblique view.

[0027] Fig. 2 shows an exemplary outer plate of the brake disc assembly.

[0028] Fig. 3 shows an exemplary inner plate of the brake disc assembly.

[0029] Fig. 4 shows an exemplary arrangement of the brake disc assembly in an E-axis. Fig. 5 shows a schematic view of a first possible embodiment of a multi-disc brake, wherein a ball ramp body is shown in a frontal view and the multi-disc brake system in a side and partial sectional view.

[0030] Figs. 6a and 6b show two schematic views of possible designs of the multi-disc brake.

[0031] It should be noted at the outset that in the differently described embodiments, identical parts are provided with the same reference numerals or component designations, and the disclosures contained in the entire description can be applied analogously to identical parts with the same reference numerals or component designations. Furthermore, the positional designations chosen in the description, such as top, bottom, side, etc., refer to the figure directly described and illustrated, and these positional designations must be applied analogously to the new position if the position changes.

[0032] Figures 1 to 3 show a brake disc assembly 1 and its components. The brake disc assembly 1 has several outer discs 2 and several inner discs 3, which can also be referred to as brake discs. The outer discs 2 are arranged alternately with the inner discs 3 in an axial direction 4. The inner discs 3 are adjustable relative to the outer discs 2 in the axial direction 4 by means of a corresponding actuating mechanism, so that a frictional connection is formed between the inner discs 3 and the outer discs 2. The inner discs 3 have a base body 5 that is at least approximately annular in shape, with a first surface 6 and a second surface 7 opposite this in the axial direction 4. At least one friction lining 8 is arranged on each of the first and / or the second surface 6 and 7. The inner discs 3 are therefore so-called lining discs. However, it is also possible that the inner discs 3 do not have any friction linings 8.

[0033] The friction linings 8 can be designed according to the prior art. The outer lamellae 2 also have an at least approximately ring-shaped base body 9, which, however, is free of friction linings. The outer lamellae 2 are therefore the so-called counter lamellae, which can be brought into frictional engagement with the friction linings 8 of the inner lamellae 3. However, it is also possible that friction linings 8 are arranged on one of the two surfaces 10, 11 of the outer lamellae 2, particularly if no friction linings 8 are arranged on the inner lamellae 3. The friction lining(s) 8 can be formed by sintered friction linings or resin-bonded friction linings, as are known in principle for friction lamellae from the prior art. The counter lamellae can be made of steel or aluminum, etc. Likewise, the base body of the inner lamellae can be made of steel or aluminum, etc. The inner lamellae 3 are rotationally fixed to a first component, for example, a shaft.The inner lamellae 3 can have radially inwardly projecting projections 12 on a radially inner end face, which engage in corresponding recesses of the first component. The outer lamellae 2 are rotationally fixed to a second component, which can be, for example, a housing. The outer lamellae 2 can have radially outwardly projecting projections 13 on a radially outer end face, which can engage in corresponding recesses on a radially inner surface of the second component. The brake lamella assembly 1 is part of a brake friction system in a vehicle (not shown). This vehicle also has an electric motor as a drive system, in addition to the brake lamella assembly 1. This electric motor can be the main drive (electric car) or an auxiliary drive (hybrid car).

[0034] Figure 4 schematically illustrates that at least one brake plate assembly 1 is arranged on the drive shaft 31 of an electric axle drive 15 of the motor vehicle. In particular, this embodiment shows one brake plate assembly 1 immediately before and one immediately after a differential 16 of the motor vehicle. The differential 16 is connected to an electric motor 17. The brake plate assemblies 1 can be encapsulated in housings 14, which prevent particles from escaping into the environment. As schematically shown, the brake plate assemblies are actuated by a ball ramp mechanism.

[0035] Figure 5 shows a multi-disc brake system 18. A brake disc assembly 1 is shown, arranged in a brake basket 19. A brake actuator 20 acts on the brake disc assembly 1 by actuating it, i.e., compressing it, so that friction is established between the inner and outer discs and thus between the inner brake basket 19a and the outer brake basket 19b. In the illustrated embodiment, inner discs with internal teeth are connected to the inner brake basket 19a. These inner discs 3 have a friction lining. Outer discs 2 are connected to the outer brake basket 19b. These outer discs are, for example, steel discs with external teeth and are connected to the outer brake basket 19b by means of these teeth. The inner discs rotate about an axis 15a with the E-axis 15, while the outer discs remain stationary. According to another embodiment, the design is also possible in reverse, i.e.,Steel lamellae are used as inner lamellae and friction lamellae as outer lamellae. The outer brake basket 19b is designed as a brake actuator 20. In the present embodiment, the brake actuator comprises a ball ramp 21 with a first ball ramp body 22 and a second ball ramp body 23, and at least one rotating body 24, in particular a ball, arranged between the first and the second ball ramp bodies 22, 23. Preferably, a number of balls 24, in particular 3 balls, are provided in the ball ramp.

[0036] In the present embodiment, the first ball ramp body 22 is supported on the outer brake cage 19b by a suitable support 25. This support 25, particularly axial support, can be provided by a suitable support ring arranged on the brake cage. As schematically shown in Fig. 5, the first ball ramp body 22 has at least one track 26, in this case three delimited tracks with at least partially varying depths, on which the rotating body(s) 24 (for clarity, only a single rotating body is referenced in the drawing) rolls and / or slides. Thus, the first ball ramp body 22 is rotated, for example, by means of an external toothing 27 on the ball ramp body 22. For example, an electric drive can be provided that engages directly or indirectly with the toothing 27 and rotates the second ball ramp body 22 relative to the stationary outer brake cage 19b.The rotating body 24 rolls or slides along the track 26, thereby pressing the second ball ramp body 23 towards the brake plate assembly. This compresses the brake plate assembly between the second ball ramp body 23 and the counter-holder 28, which is part of the brake basket 19. In particular, the actuating element 29 presses against the first inner plate, which is designed as a friction plate. The actuating element 29 is not shown in section here for clarity. The actuating element 29 is either part of the second ball ramp body 23 or rigidly connected to it as a separate component. This results in contact between the inner and outer plates, thus initiating the braking process.

[0037] As shown in Fig. 5, it is possible for the second ball ramp body 23, with the actuating element 29, to act directly on or press against the first brake plate, in particular the friction lining of the first brake plate. The actuating element 29 thus has a direct active actuating surface that is in contact with the friction lining of the first brake plate. The counterholder 28 can also be in direct contact with the brake plate, thereby eliminating the need for a steel plate. This allows for the elimination of two steel plates. These direct contacts between the actuating element 29 and the counterholder 28 are made possible, for example, by the fact that the direct active actuating surface, which rests against the plate, is made of a sintered material. This special manufacturing process enables specific material properties for this contact surface with the friction plate.

[0038] It should be mentioned that the actuating element 29 and the counterholder 28 have a high thermal storage mass, which contributes to a particularly thermally robust braking system.

[0039] A further advantage of this embodiment is that the actuating element and the counter-holder form an internal frictional connection, essentially acting as a brake caliper. This means that no actuation forces act on the components of the transmission, particularly the electric transmission, which is responsible for actuating the brake.

[0040] The second ball ramp body 23 also has a recess 30, which is provided, for example, for a bearing point. The embodiment according to Fig. 5 is characterized by a particularly compact design. The second ball ramp body 23 is shaped in a cup-like form, such that a portion of the ball ramp body projects radially beyond the brake disc assembly and is axially projecting forward or backward, so that at least a portion of the brake disc assembly is radially covered by the ball ramp body 23. This saves installation space and allows for a particularly compact design.

[0041] Figures 6a and 6b show possible arrangements of the multi-plate brake. These differ in the mounting / arrangement of the ball ramp bodies 22, 23 and the outer brake basket 19b, respectively. In Figure 6a, the outer plates 2 are connected to the brake basket 19b. In a particular embodiment, the ball ramp body 23 is connected to the housing of the electric drive or electric gearbox 32. The counter-holder 28 is slidably designed and, in this case, presses against the actuating element 29 connected to the ball ramp body 23. In Figure 6b, a fixed connection of the outer plates via the counter-holder 28 and the outer brake basket 19b is achieved. The counter-holder 28 or the outer brake basket 19b is connected to the housing of the electric gearbox 32. Here, the ball ramp body 23 is arranged to be slidable with the actuating element 29 and presses against the counterholder 28 which is fixedly connected to the housing.

Claims

P a t e n t a n s p r ü c h e 1. Multi-plate brake with a brake plate assembly comprising at least one inner plate and at least one outer plate, wherein the inner and outer plates are axially arranged and wherein at least one of the at least one inner plate and / or the at least one outer plate has a friction lining and a brake actuator arranged on the brake plate assembly for actuating the brake plate assembly, wherein the brake actuator has an axially displaceable actuating element for actuating the brake plate assembly, and a counter-holder is provided on the opposite side of the brake plate assembly, wherein the counter-holder is arranged adjacent to the brake plate assembly on the side opposite the actuating element with respect to the plate assembly, characterized in that the actuating element and / or the counter-holder bears against a friction lining of at least one of the at least one inner plates and / or at least one outer plate.so that, in the event of activation of the multi-plate brake, the counterholder and / or the actuating element acts directly on the friction lining of at least one of the inner and / or outer plates, and the actuating element and / or the counterholder, which is in direct contact with the friction lining, has at least partially a sintered material structure.

2. Multi-plate brake according to claim 1, characterized in that both the actuating element and the counterholder each bear against the friction lining of at least one of the at least one inner plates and / or at least one outer plate, so that in the event of activation of the multi-plate brake the counterholder and the actuating element act directly on the friction lining of at least one of the inner and / or outer plates.

3. Multi-disc brake according to claim 1 or 2, characterized in that the actuating element and / or the counter-holder which rests against the friction lining has at least a partially sintered material structure in the area in which contact with the friction lining is present.

4. Multi-disc brake according to one of the preceding claims, characterized in that an activation mechanism for displacing the actuating element is provided, which, depending on the embodiment, is electrical and / or mechanical and / or hydraulic and / or pneumatic, and the activation mechanism is radially outside on the multi-disc pack. is arranged so that at least part of the activation mechanism radially covers the lamellar package.

5. Multi-plate brake according to one of the preceding claims, characterized in that the brake actuator arranged on the brake plate assembly for actuating the brake plate assembly comprises a ball ramp with a first ball ramp body and a second ball ramp body and at least one ball arranged between the first and the second ball ramp body, and wherein the first and / or the second ball ramp body has on its surface at least one track with at least partially varying depth, along which the at least one ball is movable, wherein the first ball ramp body is arranged on a first side, via which at least one ball is connected to the second ball ramp body in such a way that it is axially movable by rotating the first and / or second ball ramp body, and the first ball ramp body is arranged adjacent to the brake plate assembly and is configured as the actuating element for direct actuating the brake plate assembly.

6. Lamellar brake according to claim 5, characterized in that the first ball ramp body, which bears against the friction lining, has at least partially a sintered material structure on its contact surface with the friction lining.

7. Multi-plate brake according to claim 5 or 6, characterized in that the first ball ramp body, which bears against the friction lining, is cup-shaped, such that a part of the ball ramp body which projects radially beyond the brake disc assembly projects backward or forward in the axial direction, so that at least a part of the brake disc assembly is covered in the radial direction by the ball ramp body.

8. Multi-plate brake according to claim 7, characterized in that the at least one ball of the ball ramp is arranged radially outside the brake disc assembly and at least partially covers it.

9. Lamellar brake according to one of claims 5 to 7, characterized in that the first and / or second ball ramp body has a recess for a bearing seat.

10. Lamellar brake according to one of claims 5 to 9, characterized in that the ball ramp can be actuated via an electric motor, so that the first and / or the second ball ramp body can be rotatable via the electric motor.

11. Multi-disc brake according to one of the preceding claims, characterized in that a sealed housing is provided and the brake disc pack is arranged in the housing in such a way that no particles of the friction linings of the brake disc pack can escape unhindered from the interior of the housing into the environment.

12. Multi-disc brake according to claim 11, characterized in that a supply of a cooling fluid for cooling the brake disc assembly is provided in the housing.

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