Search

DE-102024210867-A1 - Electromechanical brake with compensating element

DE102024210867A1DE 102024210867 A1DE102024210867 A1DE 102024210867A1DE-102024210867-A1

Abstract

The invention relates to an electromechanical brake (10) for a motor vehicle. The electromechanical brake (10) comprises an electric motor (14) which rotates a spindle (22) of a spindle drive unit (26) arranged in a brake caliper housing (16), so that a spindle nut (38) and a brake pad (56) attached to the spindle nut (38) are displaceable in an axial direction (40) of the brake caliper housing (16) to apply a braking force (F<sub> B </sub>). A compensating element (52) is arranged between the spindle nut (38) and the brake pad (56), via which radial forces (F <sub>R</sub> ) between the brake pad (56) and the spindle nut (38) can be absorbed, and which allows relative radial movement between the brake pad (56) and the spindle nut (38).

Inventors

  • Matthias Greiner

Assignees

  • Robert Bosch Gesellschaft mit beschränkter Haftung

Dates

Publication Date
20260513
Application Date
20241113

Claims (7)

  1. Electromechanical brake (10) for a motor vehicle, comprising an electric motor (14) which rotates a spindle (22) of a spindle drive unit (26) arranged in a brake caliper housing (16), such that a spindle nut (38) and a brake pad (56) attached to the spindle nut (38) are displaceable in an axial direction (40) of the brake caliper housing (16) for applying a braking force (F B ), characterized in that a compensating element (52) is arranged between the spindle nut (38) and the brake pad (56), via which radial forces (F R ) between brake pad (56) and spindle nut (38) can be absorbed, and which enables a relative radial movement between brake pad (56) and spindle nut (38).
  2. Electromechanical brake (10) according to Claim 1 , characterized in that the compensating element (52) is made of a rubber material.
  3. Electromechanical brake (10) according to Claim 2 characterized in that the rubber material is made of a nitrile butadiene rubber.
  4. Electromechanical brake (10) according to one of the preceding claims, characterized in that a retaining element (44) is arranged on the spindle nut (38), by means of which the compensating element (52) is received and held.
  5. Electromechanical brake (10) according to one of the preceding claims, characterized in that at least one guide element (42) is arranged in the brake caliper housing (16), over which the spindle nut (38) is guided radially.
  6. Electromechanical brake (10) according to one of the preceding claims, characterized in that the spindle drive unit (26) is a ball screw drive.
  7. Motor vehicle comprising an electromechanical brake (10) according to one of the preceding claims.

Description

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 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. The DE 19607 295 C1 This describes a brake actuator for an electric vehicle brake. The vehicle brake comprises an electric motor with a stator and a rotor connected to the spindle nut of a spindle drive assembly. The spindle is axially movable by rotating the spindle nut. A sliding bearing is arranged between the spindle and a brake piston, reducing lateral forces on the spindle assembly. In the DE 20 2010 005 051 U1 This describes an adjusting bolt of a disc brake. The adjusting bolt acts on an intermediate piece located between the brake pad and the adjusting bolt. The intermediate piece forms a recess into which one end of the adjusting bolt projects. A sliding disc is arranged in the recess between the adjusting bolt and the intermediate piece, allowing the intermediate piece to move laterally relative to the adjusting bolt. A spring element is located between the adjusting bolt and the intermediate piece, which centers the intermediate piece relative to the adjusting bolt after a lateral displacement. The intermediate piece decouples any lateral force emanating from the brake disc from the adjusting bolt. The object underlying the invention is to provide an electromechanical brake which has a longer service life. 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 The invention provides an electromechanical brake for a motor vehicle. The electromechanical brake comprises an electric motor which rotates a spindle of a spindle drive unit arranged in a brake caliper housing, such that a spindle nut and a brake pad attached to the spindle nut are displaceable in an axial direction of the brake caliper housing to apply a braking force. A compensating element is arranged between the spindle nut and the brake pad, which absorbs radial forces between the brake pad and the spindle nut and allows relative radial movement between the brake pad and the spindle nut. A compensating element is a component that balances forces between the brake pad and the spindle nut. While the compensating element can absorb and transmit axial and radial forces between the brake pad and spindle nut, it also allows for relative radial movement between them. This relative movement reduces radial forces, particularly force peaks. The reduced radial forces minimize tilting of the spindle nut relative to the spindle, thus reducing wear in the threads of the spindle drive unit. This improves the durability of the spindle drive unit and, consequently, the electromechanical brake. A longer service life can therefore be achieved. Preferably, the compensating element is designed to allow relative axial movement between the brake pad and the spindle nut. This mobility reduces axial force peaks, thereby reducing wear in the spindle drive unit and increasing the service life of the electromechanical brake. In a preferred embodiment of the invention, the compensating element is made of a rubber material. Such a compensating material has the advantage of being inexpensive, thus enabling the electromechanical brake to be provided economically. Furthermore, a rubber material has the property of exhibiting a damping effect, so that the force is distributed more evenly. Peaks can be softened, thus reducing wear in the spindle drive unit. In a further preferred embodiment of the invention, the rubber material is made of nitrile butadiene rubber. Nitrile butadiene rubber has the advantage of being very robust. In particular, it is very temperature-resistant due to the high temperatures occurring in the area of the brake pads. It is also very resistant to splashing water, oil, and brake dust. Accordingly, this material is particularly suitable for the intended position in the area between the brake pad and the spindle nut. Preferably, a retaining element is arranged on the spindle nut, by which the compensating element is received and held. Such a retaining element allows the compensating element to be easily held between the spindle nut and the brake pad. In an advantageous embodiment, at least one guide element is arranged in the brake caliper housing, by which the spindle nut is guided radially. This guide element is designed such that it transmits a radial force from the spindle nut into the brake