A spring retainer includes a locking member which locks one end side of the piston spring, and a rod-shaped member (82) of which one end is in contact with the locking member to restrict a length of the piston spring and the other end is fixed to the piston (11), and the rod-shaped member (82) is installed in a concave portion (140) of the piston (11), and the concave portion (140) has a protruding portion (142), which is extruded by plastic deformation toward a radial direction of the concave portion (140) and is formed of the same member as the opening circumferential edge portion (141), in the vicinity of the opening circumferential edge portion (141).

A brake booster for a brake master cylinder of a motor vehicle includes a drive motor that is connected/connectable by a gear unit to a pressure piston for the brake master cylinder, the gear unit converting a rotational motion of the drive motor into a translational motion of the pressure piston to actuate the brake master cylinder, and the gear unit including a rotatable spindle nut and a non-rotatable spindle rod having intermeshing trapezoidal threads that have have a flank clearance and a tip clearance that are greater than a bottom clearance.

A modular braking device for a hydraulic motor vehicle brake system, which is optimized for remote actuation, including a hydraulic booster stage with a booster housing, a main brake cylinder mounted thereon, a booster piston which is displaceable therein and delimits a pressure chamber which is supplied directly with pressure medium by a motor pump unit.

Systems and methods for providing open loop motor control for an electromechanical brake when closed loop motor control fails. The method includes determining, with an electronic controller, whether a rotor position sensor or a current sensor is not operating correctly, generating, with the electronic controller, a generated control signal for controlling a permanent magnet synchronous machine, and activating, with the electronic controller, the permanent magnet synchronous machine using the generated control signal to generate a stator magnetic field to operate the rotor of the permanent magnet synchronous machine of the electromechanical brake.

A pneumatic brake booster having a booster housing. The booster housing has at least two thin-walled shell elements and an elastomer sealing element. The sealing element has a sealing bead, which is of encircling form radially at the outside, and at least one rolling diaphragm portion which adjoins the sealing bead. The sealing bead is sealingly clamped in a clamping space between the shell elements. The clamping space is formed by walls which are generated in the shell elements by deformation, its radial inner wall formed by a tubular, axially forwardly extending projection, which is folded at its front edge, of the second shell element. It is proposed that a bead-side rear wall of the clamping space is formed by an encircling, radially outwardly projecting collar which is formed on the second shell element.

A method for ascertaining information relating to a mechanically effective power of an active brake booster of a braking system of a vehicle, including: ascertaining a first piece of information relating to an assisting force that is effectuated with the aid of the operated active brake booster, ascertaining a second piece of information relating to a pressure force in a master brake cylinder of the braking system, situated downstream from the active brake booster, the pressure force acting counter to the operated active brake booster, ascertaining a third piece of information relating to a spring force of at least one spring of the active brake booster and/or of the braking system, the spring force acting counter to the operated active brake booster, and establishing the information relating to the mechanically effective power of the active brake booster, taking into consideration the first, second, and third pieces of information.

A hydraulic vehicle braking system comprises a master cylinder having at least one piston displacably accommodated therein, a mechanical actuator that is coupled, or can be coupled, to a brake pedal for actuating the piston, and an electromechanical actuator. The electromechanical actuator is likewise provided for actuating the piston and can be activated, at least for boosting or generating brake force, when the brake pedal is actuated. Furthermore, a valve arrangement is provided, which has a first valve per wheel brake for selectively uncoupling the wheel brake from the master cylinder, and a second valve for selectively reducing the brake pressure at the wheel brake. The valve arrangement can be controlled at least within the framework of an ABS control mode.

This hydraulic braking device is provided with: a tubular cylinder; an assisting piston, which is housed in the cylinder so as to be able to move reciprocally, faces a reservoir formed inside the cylinder, and assists a master piston, in a master cylinder, that generates hydraulic pressure for generating a braking force by reciprocally moving from one side to the other as a result of a fluid flowing into the reservoir from a supply source; and a seal member, which is elastically deformable and which seals the reservoir. When the assisting piston is at a location on one side, the reservoir is compartmentalized into a first chamber that communicates with the supply source, and a second chamber that communicates with the first chamber through a restricting flow passage, and the seal member seals the second chamber.

A brake booster for a brake master cylinder of a motor vehicle includes a drive motor that is connected/connectable by a gear unit to a pressure piston for the brake master cylinder, the gear unit converting a rotational motion of the drive motor into a translational motion of the pressure piston to actuate the brake master cylinder, and the gear unit including a rotatable spindle nut and a non-rotatable spindle rod having intermeshing trapezoidal threads that have have a flank clearance and a tip clearance that are greater than a bottom clearance.

A hydraulic actuator for supplying a hydraulic brake pressure to service brakes of a vehicle includes an actuator cylinder including a piston. A hydraulic working pressure of a brake fluid can be set in accordance with a position of the piston. The brake fluid is supplied from a hydraulic reservoir assigned to the hydraulic cylinder, and the hydraulic working pressure prevails in a working space of the actuator cylinder and can be output via an actuator output port on the actuator cylinder in order to supply a hydraulic brake pressure in accordance with the hydraulic working pressure. The hydraulic actuator further includes an electrically controllable motor. A rotary motion brought about by the electrically controllable motor can be converted by a conversion mechanism into a translational motion of the piston parallel to a longitudinal direction thus enabling a hydraulic brake pressure to be supplied by electric control of the motor.