The invention relates to a disc brake, comprising a brake carrier, a brake caliper, brake shoes, and an actuating piston. The brake carrier has at least one mounting point for mounting on a vehicle. The actuating piston is displaceably accommodated on the brake caliper and is actuatable for carrying out a service brake function of the disc brake. At least one further actuating piston is provided, which in the direction of its longitudinal axis is displaceably accommodated on the brake caliper. For carrying out the service brake function, the at least two actuating pistons are actuatable, and for carrying out a parking brake function, one of the actuating pistons is actuatable. The invention further relates to a disc brake system and a parking brake system.

In some examples, a brake system includes a piston configured to cause a compression of a disc stack. The piston includes a piston body configured to compress a cap face of a piston cap against a pressure plate to cause the compression of the disc stack. The cap face may define a convex surface. The piston cap may be configured such that the convex surface reduces it curvature when the cap face is compressed against the pressure plate. In examples, the piston cap is configured to elastically deform to cause the cap face to reduce the curvature when the cap face is compressed against the pressure plate.

A disc brake, in particular for commercial vehicles, has an adjustment device for compensating for brake lining/brake disc wear. The adjustment device is arranged at least partially inside an interior space of the brake caliper and has an adjustment gear with an adjustment nut having an internal thread, and an adjustment spindle screwed therein with an external thread. For adjustment during normal operation of the brake, the adjustment nut is rotated in relation to the adjustment spindle, which is fixed against rotation. A first sealing device at least partially seals off an annular space on the brake disc side between the inner wall of a through-opening in the brake caliper and the axially adjustable adjustment spindle, which extends through the through-opening and toward one of the brake linings, wherein the first sealing device is held on the caliper at one end.

A brake piston for a disc brake assembly has a body portion and an end face of the body portion. An annularly extending first portion of the end face has a first radius and an annularly extending second portion of the end face has a second radius that is less than the first radius. A plurality of first ribs extend radially inward from the first portion to the second portion and a plurality of second ribs extends radially outward from the second portion to the first portion. The first and second ribs are interspaced. The second portion and the second ribs are recessed into the end face relative to the first portion and the first ribs.

A brake assembly including an operating shaft, a yoke, and a rotating element. The rotating element bearing may be positioned between a convex bearing surface of the operating shaft and a concave bearing surface of the yoke such that the rotating element bearing may be configured to move relative to the operating shaft and relative to the yoke during actuation of the brake.

A disc brake includes an inner pad and an outer pad, a pressing device, and a housing. The pressing device includes: at least one first pressing member movable toward a rotor and at least one second pressing member movable away from the rotor; and a frame held by the housing movably in an axial direction and configured to be moved by movement of the at least one second pressing member. A point of action of a resultant force of at least one pressing force applied from the at least one first pressing member to the inner pad is located on a trailing side of a centroid of the inner pad, and/or a point of action of a resultant force of at least one pressing force applied from the at least one second pressing member to the frame is located on a leading side of a frame central axis.

The present invention relates to an anti-drag structure of automobile brake calipers, comprising a brake caliper body which is provided with a cylinder bore and a brake claw arranged along the axis of the cylinder bore in an extending mode; and a cylindrical piston bush is pressed in the cylinder bore by interference fit, a step ring groove is formed in the inner wall of the piston bush and composed of a major diameter ring groove and a minor diameter ring groove which have rectangular sections. The present invention can improve the generality of the brake caliper body through the arrangement of the piston bush and improve the standardization of production manufacturing of brake calipers, and can reduce the residual drag moment of the brake caliper and the fuel consumption with the rubber seal ring and the phenolic resin PF ring to achieve the purpose of emission reduction.

The present disclosure provides a disk brake capable of making it easier for the piston to return than conventional ones when the brake is released from a state where the brake is applied. In the disk brake, the seal groove 5 includes a front wall 51, a rear wall 52 farther from the brake rotor than the front wall 51 in the axial direction Dl, and a bottom wall 53 extending along the axial direction Dl between the rear wall 52 and the front wall 51. The bottom wall 53 includes a front bottom wall 53a adjacent to the front wall 51 and a rear bottom wall 53b adjacent to the rear wall 52. The rear bottom wall 53b has a depth d2 from the inner circumferential surface 42a of the cylinder 42, the depth d2 being larger than a dimension d3 of the uncompressed piston seal 6 in the direction of the depth d2 and being larger than a depth d1 from the inner circumferential surface 42a of the cylinder 42 of the front bottom wall 53a.

A hydraulic caliper disc brake includes an opposing pair of pistons adapted to act on an opposing pair of washers adapted to act on an opposing pair of stator assemblies, each of the pistons comprising a spherical piston face, each of the washers comprising a spherical washer face abutting a respective one of the spherical piston faces, and a straight washer face opposite the spherical washer face and abutting a respective one of the stator assemblies.

The invention relates to a hydraulic brake system for a vehicle, comprising a cylinder (3) and a piston (4) movably arranged inside the cylinder (3), wherein the piston (4) has a closed end, an open end (6) and a piston wall surrounding a cavity (8) of the piston (4) between the closed end and the open end (5), the piston (4) being movable along a longitudinal axis (5) of the cylinder (3) by hydraulic pressure within the cavity (8) for pressing at least one brake pad (9) against a brake disc (2). An outer diameter of the piston (4) is smaller in a central section (13) between the open end (6) and the closed end than at the open end (6) and at the closed end so that, in the central section (13), a space (14) remains between the piston wall and an inner wall of the cylinder (3).