A hydraulic apparatus is disclosed, which includes a hydraulic cylinder body, a piston, a push assembly, and a first sealing component; the hydraulic cylinder body is of a hollow cylinder shape, provided with a first opening and a second opening respectively at two ends; the piston is disposed in the hydraulic cylinder body and is located at the first opening; the first sealing component covers the second opening; the hydraulic cylinder body, the piston, and the first sealing component are configured to form a hydraulic chamber; the hydraulic cylinder body is provided with a liquid flow opening which is located between the first sealing component and the piston; and the piston is configured to be enabled to move in the hydraulic cylinder body, driven by the push assembly.

A braking system for a motor vehicle has a plurality of hydraulic brake units for braking each braking one wheel of the motor vehicle and a first electric parking brake actuator for braking a first wheel and a second electric parking brake actuator for braking a second wheel. A first control device comprises a first hydraulic controller which is designed and set up to drive the plurality of hydraulic brake units. In order to ensure parking brake redundancy, the first control device has a driver for driving the first parking brake actuator. A second control device is also provided, which comprises a driver for driving the first parking brake actuator and a driver for driving the second parking brake actuator.

A disc brake device includes a pad, a caliper including a cylinder, a piston, and a rotary-to-linear motion conversion mechanism. The piston is divided into two parts that are a piston main body and a piston cap. The rotary-to-linear motion conversion mechanism includes a rotary member and a linear motion member. A unidirectional rotation regulating portion between the piston main body and the piston cap is configured to regulate relative rotation of the piston main body in a forward rotation direction with respect to the piston cap when the rotary member is driven to rotate in the forward rotation direction, and to allow relative rotation of the piston main body in a reverse rotation direction with respect to the piston cap when the rotary member is driven to rotate in the reverse rotation direction.

A spring brake actuator for a commercial vehicle includes a service brake portion (4) and a spring brake portion (6) that has a housing (8, 108) with a first end (10, 110) proximal to the service brake portion (4), a wall section (12, 112) extending from the first end (10, 110), a second end (14, 114) distal to the service brake portion (4), and a locking mechanism (16, 116) for locking the first and second ends (10, 110, 14, 114) to the wall section (12, 112). The locking mechanism (16, 116) is arranged between the wall section (12, 112) and the second end (14, 114) of the housing (8, 108).

A vehicle hill descent control system and method for controlling a vehicle during a hill descent receives inputs from an accelerator pedal position sensor and a brake pedal sensor. The method controls the engine drivetrain system to engine idling and controls the braking control system to maintain vehicle speed by increasing braking torque to minimize or offset a vehicle speed increase due to gravity. In vehicle hill descent mode, when a vehicle user actuates the accelerator pedal, the engine idling does not change. Instead, the electronic control unit operates to decrease braking torque so the vehicle speed is increased.

A pedal-travel simulator of a hydraulic power vehicle brake system is connected to a brake-fluid reservoir by way of a groove between two piston seals of a power brake-pressure generator. Any air bubbles in the brake fluid get out of the pedal-travel simulator into the brake-fluid reservoir, and the piston seals are lubricated with the brake fluid.

A bake piston, which is arranged on a brake caliper of a disc brake of a vehicle, has a first and a second tubular piston body portion which are connected together at a first axial end of the brake piston via an annular end wall. The second piston body portion forms a receptacle in which a spindle nut of a spindle drive is accommodated so as to be axially displaceable and not rotatable relative to the brake piston, and receives a drive spindle. The first piston body portion has a radially inwardly directed floor region. The end wall is axially stepped towards the outside and has a radially outer portion and a radially inner portion which each have an end face pointing axially away from the brake piston, wherein the end face of the radially inner portion is axially offset relative to the end face of the radially outer portion in the direction towards the second axial end of the brake piston.

An electro-hydraulic actuator includes: a motor output rotative power; an external gear pump activated by the motor; a hydraulic actuator operated by a pressurized working fluid supplied by the external gear pump; a manifold block in which a flow channel forming a working fluid circuit of the hydraulic actuator is incorporated; a first portion to store the motor; a second portion to store the external gear pump, the hydraulic actuator, and a reservoir; and a coupling portion to couple the first portion and the second portion in a liquid-tight state. The coupling portion includes a communication hole through which the first portion and the second portion communicate, a rotational shaft of the motor and a driving shaft of the external gear pump are joined to each other, and the external gear pump is attached to the coupling portion while being stored in the manifold block.

The present disclosure relates to a method for operating a vehicle brake. The vehicle brake includes a hydraulic service brake having an actuating piston, which for generating a first braking force component is movable, under the action of a hydraulic pressure, into an actuating position in which the actuating piston presses a friction lining against a rotatingly supported brake disc, and an electric parking brake, with an actuating element, that is designed to build up a second braking force component that acts on the brake disc. The method includes ascertaining the hydraulic pressure, determining a first braking force component, establishing a second braking force component to be set by means of the parking brake, based on the first braking force component and a desired total braking force, and establishing a position of the actuating element of the parking brake to be set.

An electrically actuated parking brake has a single electric motor producing a torque, a first torque limiting device with a first spring force, and a second torque limiting device with a second spring force. The first torque limiting device fully transmits a first portion of the torque to a first spindle until a first clamp force overcomes the first spring force and the second torque limiting device fully transmits a second portion of the torque to a second spindle until a second clamp force overcomes the second spring force. When the first clamp force overcomes the first spring force and the second spring force overcomes the second clamp force, the first portion of the torque that exceeds the first spring force is transmitted to the second spindle by the second torque limiting device.