Electromechanical brake with gearbox housing as an extruded part

Abstract

The invention relates to an electromechanical brake (10) for a motor vehicle. The electromechanical brake (10) comprises an electric motor (14) which, via a gearbox (26), rotaryally drives a spindle drive unit (38) arranged in a brake caliper housing (50), so that a brake actuator (62) is axially adjustable for applying a braking force. The gearbox (26) is arranged in a gearbox housing (18) separate from the brake caliper housing (50), which is connected to the brake caliper housing (50), wherein the gearbox housing (18) is designed as an extruded part.

Description

[0001] The present invention relates to an electromechanical brake for a motor vehicle. Furthermore, the invention relates to a motor vehicle which has such an electromechanical brake. State of the art

[0002] The service brake is typically a brake system that uses brake fluid to press a brake piston and brake pad against a brake disc to slow the vehicle. With the increasing electrification of vehicle components, the service brake is also being developed as an electromechanical brake, thus eliminating the need for brake fluid and the associated complex valve and line system. Such an electromechanical brake could also significantly reduce maintenance requirements.

[0003] WO 2020 / 230000 A1 describes an electromechanical disc brake comprising a caliper housing in which a pressure device is arranged to apply a preload to a brake pad. The pressure device includes a spindle drive unit with a spindle and an axially movable spindle nut. The spindle nut is connected to a reduction gear. Additionally, an angular contact ball bearing is provided, which rotatably supports the spindle nut and absorbs an axial force from the spindle nut.

[0004] EP 1 030 979 B1 discloses an electromechanical braking device for braking a motor vehicle wheel. The braking device has a brake caliper in which an electric motor is arranged. The electric motor drives a spindle drive unit, via which brake pads arranged on a brake caliper of the brake caliper can be applied to a brake disc for braking.

[0005] Although electromechanical brakes are well-known from the prior art, there is a persistent drive to develop a lighter and more economical electromechanical brake compared to competing products. Economic efficiency can be improved, for example, by reducing material costs, decreasing the number of parts, simplifying part manufacturing, or simplifying assembly.

[0006] The object underlying the invention is to provide an electromechanical brake for a motor vehicle which is simpler and more economical to manufacture.

[0007] The problem is solved by an electromechanical brake according to claim 1. Preferred embodiments are set forth in the dependent claims. Disclosure of the invention

[0008] The invention provides an electromechanical brake for a motor vehicle. The electromechanical brake comprises an electric motor which, via a gearbox, rotaryally drives a spindle drive unit arranged in a brake caliper housing, so that a brake actuator is axially adjustable for applying a braking force. The gearbox is arranged in a gearbox housing separate from the brake caliper housing, which is connected to the brake caliper housing, wherein the gearbox housing is designed as an extruded part.

[0009] According to the invention, the brake caliper housing and the gearbox housing are designed as separate housings which are connected to each other in an assembled state. Accordingly, the brake caliper housing and the gearbox housing can also be manufactured using different processes. According to the invention, the gearbox housing is designed as an extruded part. This housing is thus manufactured by extrusion. This manufacturing process has the advantage that the gearbox housing can be produced in a single manufacturing step. To enable the gearbox housing to be manufactured by extrusion, it is designed accordingly. The production of this housing is therefore faster and simpler. Consequently, the gearbox housing, and thus the entire electromechanical brake, can be manufactured more economically.

[0010] In a preferred embodiment of the invention, the gearbox housing is made of aluminum. Manufacturing the gearbox housing from aluminum has the advantage that such a material can be easily machined by extrusion. Furthermore, aluminum is lightweight, which reduces the weight of the electromechanical brake. Due to aluminum's high thermal conductivity, heat generated during prolonged use of the electromechanical brake is dissipated more effectively.

[0011] In a further preferred embodiment of the invention, the gearbox housing has areas that have been machined. Such machining can be carried out, for example, by milling or turning. The machining process removes unnecessary material from the gearbox housing, thereby further reducing its weight.

[0012] Preferably, the gearbox housing has an external mounting structure to which attachments can be fastened. By forming this mounting structure through extrusion, it can be created in the same manufacturing step as the gearbox housing itself. The mounting structure can therefore be formed without additional effort. Advantageously, the mounting structure can be used to attach components, making it easier, for example, to fix cables to the gearbox housing.

[0013] In an advantageous further development, the gearbox housing forms a mounting surface for the electric motor and / or a mounting surface for a control unit that controls the electric motor. This mounting surface allows the electric motor and the control unit to be attached to the gearbox housing without any additional components. This eliminates the need for components that would otherwise be used to attach the electric motor to the gearbox housing. The mounting surface also provides sufficient surface area for the electric motor and the control unit to rest against. Consequently, the manufacturing costs for such additional components can be saved, making the electromechanical brake more economical to produce.

[0014] Advantageously, the interface between the gearbox housing and the brake caliper housing is round. The interface is defined as the area where the two housings are connected. This rounded interface allows for flexible positioning of the gearbox housing relative to the brake caliper housing. Consequently, the gearbox housing can be rotated relative to the brake caliper housing before being secured. The position of the gearbox housing relative to the brake caliper housing can therefore be variably selected according to the available installation space. This eliminates the need for additional variants with different angles between the gearbox and brake caliper housings. Such an electromechanical brake can thus be manufactured more economically and offers greater application versatility.

[0015] The invention further specifies a motor vehicle which has such an electromechanical brake. The advantages and properties described above are achieved with such a motor vehicle.

[0016] Exemplary embodiments of the invention are shown in the drawing and explained in more detail in the following description. It shows: Fig. 1 Longitudinal sectional view of an electromechanical brake according to an embodiment of the invention, Fig. 2 Perspective view of an exemplary embodiment of the gearbox housing, Fig. 3 Side view of the electromechanical brake according to an exemplary embodiment, and Fig. 4 Perspective view of the gearbox housing according to an exemplary embodiment.

[0017] In Fig. Figure 1 shows a longitudinal sectional view of an electromechanical brake 10 according to an embodiment of the invention. The electromechanical brake 10 comprises an electric motor 14, which is arranged externally on a gearbox housing 18 of the electromechanical brake 10. The electric motor 14 drives a gearbox 26 arranged in the gearbox housing 18 via a motor shaft 22. The gearbox 26 consists of a worm gear (not shown) formed on the motor shaft 22, which meshes with a worm wheel 30. The worm wheel 30 is fixedly mounted on a spindle 34 of a spindle drive unit 38. The spindle 34 is thus rotatable via the worm wheel 30. The electromechanical brake 10 also has an angular contact ball bearing 42, by means of which the spindle 34 is rotatably mounted.

[0018] At one axial end of the spindle 34, a pinion 46 is additionally arranged, via which a parking brake function can be implemented. The gearbox housing 18 is connected to a brake caliper housing 50, which is separate from the gearbox housing 18. According to the invention, the gearbox housing 18 is designed as an extruded part. This simplifies its manufacture. The brake caliper housing 50 is connected to a brake caliper 54 of the electromechanical brake 10. The spindle drive unit 38, which here is designed as a ball screw drive, is arranged in the brake caliper housing 50. By rotating the spindle 34, a spindle nut 58 of the spindle drive unit 38, and thus also a brake adjuster 62 arranged on the spindle nut 58, can be axially displaced. To protect the spindle nut 58 from rotation, it has radial anti-rotation lugs 66 which engage in anti-rotation slots 70.

[0019] Fig. Figure 2 shows a perspective view of an embodiment of the gearbox housing 18. This figure shows that a retaining geometry 74 is formed on the gearbox housing 18, via which attachments can be fastened to the gearbox housing 18. Such a retaining geometry 74 can be formed just as easily by extrusion. Furthermore, a mounting surface 78a for a control unit 82 is provided on the gearbox housing 18 (see Figure 2). Fig. 3) and a mounting surface 78b for the electric motor 14 is formed. The gearbox housing 18 additionally forms a bore 86 for the motor shaft 22. Such a bore 86 is introduced into the gearbox housing 18 via a manufacturing step downstream of extrusion.

[0020] Fig. Figure 3 shows a side view of the electromechanical brake 10 according to an embodiment of the invention. In this figure, the control unit 82 is attached to the mounting surface 78a. It is also shown that the gearbox housing 18 has areas 90 that are machined after extrusion, thus reducing the weight of the gearbox housing 18. The mounting surfaces 78a, 78b and the machined areas 90 are further detailed in Fig. Figure 4 shows that an interface 94 between the gearbox housing 18 and the brake caliper housing 50 is round. This allows the gearbox housing 18, and thus the control unit 82 and the electric motor 14, to be rotated relative to the brake caliper housing 50 depending on the space requirements. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2020 / 230000 A1

[0003] EP 1 030 979 B1

[0004]

Claims

[1] Electromechanical brake (10) for a motor vehicle, comprising an electric motor (14) which rotaryally drives a spindle drive unit (38) arranged in a brake caliper housing (50) via a gearbox (26), so that a brake actuator (62) is axially adjustable to apply a braking force, characterized by , that the transmission (26) is arranged in a transmission housing (18) separate from the brake caliper housing (50), which is connected to the brake caliper housing (50), wherein the transmission housing (18) is designed as an extruded part. [2] Electromechanical brake (10) according to claim 1, characterized by , that the gearbox housing (18) is made of an aluminium material. [3] Electromechanical brake (10) according to claim 1 or 2, characterized by , that the gearbox housing (18) has areas (90) which are machined. [4] Electromechanical brake (10) according to any of the preceding claims, characterized by, that the gearbox housing (18) forms a retaining geometry (74) on the outside, via which attachment parts can be fastened to the gearbox housing (18). [5] Electromechanical brake (10) according to any one of the preceding claims, characterized by , that the gearbox housing (18) forms a mounting surface (78b) for the electric motor (14) and / or a mounting surface (78a) for a control unit (82) controlling the electric motor (14). [6] Electromechanical brake (10) according to any one of the preceding claims, characterized by , that an interface (94) between gearbox housing (18) and brake caliper housing (50) is round. [7] Motor vehicle comprising an electromechanical brake (10) according to any of the preceding claims.

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