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DE-102025112930-A1 - Friction disc brake system for a motor vehicle and electric axle drive system for a motor vehicle

DE102025112930A1DE 102025112930 A1DE102025112930 A1DE 102025112930A1DE-102025112930-A1

Abstract

The invention relates to a friction disc brake device (14) for a motor vehicle, comprising at least one first brake disc element (16) having at least one first friction surface (18), at least one second brake disc element (20) having at least one second friction surface (22), a piston (34) that can be actuated with hydraulic fluid and thereby hydraulically actuated, and a transmission element (54) formed separately from the piston (34), wherein the transmission element (54) and, via the transmission element (54), the first brake disc element (16) can be actuated by means of the piston (34) by hydraulic actuation of the piston (34), thereby bringing the friction surfaces (28, 22) into frictional contact with each other to effect braking, and wherein the transmission element (54) has a first groove (78). The piston (34) has a second groove (80). In the grooves (78, 80) an intermediate element (82) is arranged, which is formed separately from the transmission element (54) and separately from the piston (34), via which the transmission element (54) and the piston (34) are connected to each other.

Inventors

  • Alexander von Gaisberg-Helfenberg
  • Jochen Haefner
  • Thomas Stolk
  • Ursula Raithle

Assignees

  • Mercedes-Benz Group AG

Dates

Publication Date
20260513
Application Date
20250402
Priority Date
20241108

Claims (10)

  1. Friction disc brake device (14) for a motor vehicle, comprising at least one first brake disc element (16) having at least one first friction surface (18), at least one second brake disc element (20) having at least one second friction surface (22), a piston (34) that can be actuated with hydraulic fluid and thereby hydraulically actuated, and a transmission element (54) formed separately from the piston (34), wherein the transmission element (54) and the first brake disc element (16) can be actuated by means of the piston (34) by hydraulic actuation of the piston (34), whereby the friction surfaces (18, 22) can be brought into frictional contact with each other to effect braking, characterized in that: - the transmission element (54) has a first groove (78); - the piston (34) has a second groove (80); and - in the grooves (78, 80) an intermediate element (82) is arranged, which is formed separately from the transmission element (54) and separately from the piston (34), and through which the transmission element (54) and the piston (34) are connected to each other.
  2. Friction disc brake device (14) according to Claim 1 , characterized in that: - the transmission element (54) has a projection (84) extending axially from a base region (G) of the transmission element (54), in the outer circumferential surface (M1) of which the first groove (78) is formed; and - the piston (34) has an inner circumferential surface (M2) facing radially towards the outer circumferential surface (M1) and surrounding the outer circumferential surface (M1) and the first groove (78) in the circumferential direction of the friction disc brake device (14), in which the second groove (80) is formed.
  3. Friction disc brake device (14) according to Claim 2 , characterized in that an axially expanding chamfer (F) of the inner circumferential surface (M2) of the piston (34) adjoins the second groove (80) at an end (E) of the piston (34) which is axially directed towards the base region (G),
  4. Friction disc brake device (14) according to one of the preceding claims, characterized in that the intermediate element (82) is elastically deformable.
  5. Friction disc brake device (14) according to Claim 4 , characterized in that the intermediate element (82) is made of an elastomer and is therefore elastically deformable.
  6. Friction disc brake device (14) according to Claim 4 or 5 , characterized in that: - by actuating the piston (34) the piston (34) is movable axially relative to the transmission element (54) and in the direction of the friction surfaces (18, 22) under elastic deformation of the intermediate element (82), whereby an end face (SF) of the piston (34) is movable axially in direct support with a corresponding support surface (AF) of the transmission element (54); and - in the unactuated state of the piston (34) the end face (SF) is completely spaced away from the support surface (AF).
  7. Friction disc brake device (14) according to Claim 6 , characterized in that in the unactuated state of the piston (34) the piston (34) is completely spaced away from the transmission element (54).
  8. Friction disc brake device (14) according to one of the preceding claims, characterized in that the intermediate element (82) is designed as an O-ring.
  9. Friction disc brake device (14) according to one of the preceding claims, characterized in that a shoulder surface (86) is arranged in at least or exactly one of the grooves (78, 82), on which the intermediate element (82) is supported, wherein the shoulder surface (86) is conical and thus extends along an imaginary cone which widens axially towards the friction surfaces (18, 22).
  10. Electric axle drive device (10) for a motor vehicle, wherein at least one friction disc brake device (14) according to one of the preceding claims is integrated into the axle drive device (10).

Description

The invention relates to a friction disc brake device for a motor vehicle according to the preamble of claim 1. Furthermore, the invention relates to an electric axle drive device for a motor vehicle. The DE 10 2019 100 738 B3 An electric axle drive unit for a motor vehicle is known to exist, comprising an electric motor, wherein a stator of the electric motor is fixedly mounted in a housing and a rotor of the electric motor, rotatably mounted relative to the stator, is rotaryally coupled or rotatably coupled to a wheel hub. The object of the present invention is to create a friction disc brake device for a motor vehicle and an electric axle drive device for a motor vehicle, so that a particularly advantageous operation of the friction disc brake device can be realized. This problem is solved by a friction disc brake device with the features of claim 1 and by an electric axle drive device with the features of claim 10. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims. A first aspect of the invention relates to a friction disc brake device, also simply referred to as a disc brake device, friction brake device, or brake device, for a motor vehicle, also simply referred to as a vehicle. This means that the motor vehicle, preferably designed as a car, in particular a passenger car, has the friction disc brake device in its fully manufactured state. For example, the motor vehicle, in its fully manufactured state, has at least one vehicle wheel, also simply referred to as a wheel. The vehicle wheel is a ground contact element by means of which the motor vehicle can be supported or is supported downwards against a ground in the vehicle's vertical direction. If the motor vehicle is driven along the ground while it is supported downwards in its vertical direction by the ground contact element, the ground contact element rolls, in particular directly, along the ground. The aforementioned motor vehicle is thus also disclosed within the scope of the present disclosure and may therefore be part of the invention. The vehicle wheel is rotatable about a wheel axis relative to a housing of the motor vehicle, in particular the friction disc brake assembly, so that the vehicle rotates about the wheel axis relative to the housing, especially when it is rolling, particularly directly, on the ground. For example, the friction disc brake assembly can be used to brake, i.e., slow down, the vehicle wheel with respect to rotations about the wheel axis and relative to the housing, thereby braking, for example, the motor vehicle as a whole. The friction disc brake assembly is or constitutes a friction brake by means of which, for example, the vehicle wheel can be braked by friction. In particular, the friction disc brake assembly is or constitutes a service brake of the motor vehicle. The friction disc brake assembly comprises at least one first brake disc element, which has at least one first friction surface. The friction disc brake assembly also comprises at least one second brake disc element, which has at least one second friction surface. For example, it is provided that the second brake disc element, and thus the second friction surface, is rotatable about an axis of rotation relative to the housing. For example, the second brake disc element, and thus the second friction surface, is rotatable with the vehicle wheel and therefore rotatable about the axis of rotation relative to the housing. In particular, it is conceivable that the second brake disc element, and thus the second friction surface, is connected or connectable to the vehicle wheel in a torque-transmitting manner, especially in a rotationally fixed manner, and is therefore rotatable with the vehicle wheel when the vehicle wheel rotates about the wheel's axis of rotation relative to the housing, and thus rotatable about the axis of rotation relative to the housing. For example, the first brake disc element, and thus the first friction surface, is fixed to the housing and therefore cannot rotate relative to the housing around the axis of rotation. It is conceivable that the friction surfaces face each other axially, that is, in the axial direction of the friction disc brake assembly, and are thus opposite each other. The axial direction of the friction disc brake assembly, also simply referred to as the brake assembly, whose radial direction is perpendicular to the axial direction of the brake assembly and thus perpendicular to the axis of rotation, coincides with the axis of rotation and thus runs along the axis of rotation. When the axial direction is mentioned before and in the following, unless otherwise specified, this refers to the axial direction of the brake assembly (friction disc brake assembly), whose circumferential direction runs around the axial direction and thus around the axis of rotation, and lies in an imaginary plane that is perpendicular to the axial direction and thus perpendicula