A hydraulic actuator device for a hydraulic system filled with an electrically conductive medium, the hydraulic actuator device being situatable or being situated on and/or in the hydraulic system, and including at least one actuator module, which in each case is designed in such a way that at least a portion of the electrically conductive medium is acceleratable into at least one partial volume of the hydraulic system due to its interaction with an electrical current flow generated with the aid of the respective actuator module and/or with a magnetic field created with the aid of the respective actuator module, as a result of which a pressure build-up is creatable in the at least one partial volume of the hydraulic system.

The present application relates to a piston assembly for engaging two selectively engageable parts. The piston assembly has a housing defining a piston cylinder and a piston. The assembly also has a piston stroke limiter. The piston stroke limiter is configured to limit the length of a return stroke of the piston from an extended stroke position and a retracted stroke position. A crushable body acts between the piston and the piston stroke limiter and is arranged to reduce in axial length when a length of an extended stroke exceeds a length of a retraction stroke to maintain the length of the return stroke.

Provided is a caliper unit for a brake of a vehicle, in particular, a compact caliper unit capable of reducing a size, a weight, and a production cost of a component and improving fuel efficiency. The caliper unit for the brake includes an inner pad and an outer pad, which press both surfaces of a disc to generate braking force, a torque member fixed to a vehicle body and coupled to be movable forward and backward so that the inner pad and the outer pad press the disc, or the pressing of the inner pad and the outer pad to the disc is released, a caliper housing including a cylinder to which a brake hydraulic pressure is applied and a reaction force support part configured to press the outer pad to the disc, and a piston installed in the cylinder and moving forward and backward depending on a state of the brake hydraulic pressure applied to the cylinder to press the inner pad to the disc. Each of the inner pad and the outer pad has a circular shape, and a contact surface of the piston, which is in contact with the inner pad to press the inner pad during braking, has a circular shape.

A parking brake for a wheel rotor having a brake pad associated therewith includes a housing defining first and second passages. First and second pistons are provided in the respective first and second passages. Spindles are threadably connected with each piston. A clutch unit is connected to the spindles. The clutch unit has a first condition allowing relative rotation between the spindles and the pistons such that the pistons are axially movable within the passages and into engagement with the brake pad in response to hydraulic pressure applied to the pistons. The clutch unit has a second condition preventing relative rotation between the spindles and the pistons such that pistons remains engaged with the brake pad when hydraulic fluid pressure is removed from the pistons.

A parking brake for a wheel rotor having a brake pad associated therewith includes a housing defining first and second passages. First and second pistons are provided in the respective first and second passages. Spindles extend into and are connected with each piston. A clutch unit is connected to the spindles and includes a motor. The clutch unit has a first condition allowing for rotation of the spindles in response to hydraulic pressure applied to the pistons such that the pistons are axially movable within the passages and relative to the spindles into engagement with the brake pad. The clutch unit has a second condition for rotating the spindles to drive the pistons into the brake pad and apply the parking brake.

A method for controlling vehicle braking of a wheel rotor having a brake pad associated therewith includes moving a piston into engagement with the brake pad by applying hydraulic pressure to the piston. The piston is locked in place against the brake pad with a parking brake. The hydraulic pressure is removed from the piston while the parking brake is locked.

An actuation device for a hydraulic actuation system, e.g., a motor vehicle brake or an electrified clutch actuator, may include a connection for an actuation device; a pressure supply device, driven by an electromotor drive, in the form of a piston or double-stroke piston pump; a piston cylinder unit that may be actuated by means of the actuation device; and an electronic control unit. An axis of the piston cylinder unit and an axis of the pressure supply device may be arranged in parallel.

A brake assembly includes a braked member that is coupable or coupled to the vehicle wheel for a joint rotation therewith about a rotational axis, the braked member having contact surfaces that are arranged at an axial distance from one another and a braking unit that comprises a brake force generator and at least two brake pads, the brake pads being positioned in between the contact surfaces, wherein the brake force generator is configured move the brake pads axially apart from one another, thereby bringing each brake pad into contact with one of the contact surfaces of the braked member.

A brake apparatus for a vehicle may include: a caliper part fixed to a vehicle body, and having a cylinder provided therein; a piston part movably installed in the cylinder, and brought into contact with or separated from a pad plate part according to a moving direction thereof; a shaft part configured to receive a driving force from a driving part, and reciprocate in a direction parallel to a longitudinal direction of the cylinder; a pressing part connected to the shaft part, and configured to press the piston part toward the pad plate part as the shaft part is moved to one side; and an angle adjusting part provided between the shaft part and the pressing part, and configured to vary an installation angle of the shaft part with respect to the pressing part.

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.