The invention relates to an improved plunger assembly for a vehicle brake system. The plunger assembly is operable as a pressure source to control brake fluid pressure supplied to one or more wheel brakes. The plunger assembly comprises a housing defining a cylinder; a reversible motor supported by the housing and having a rotor; and a linear actuator such as a ball screw/nut mechanism driven by the motor. A plunger head is mounted in the cylinder and driven by the linear actuator in first and second opposite directions. Improvements include, the cylinder projecting from one side of a housing with an end cap covering the projecting end of the cylinder and is secured to the housing block in a generally coaxial relationship with the cylinder. The cylinder and the end cap cooperate to define a fluid passageway between the end of the cylinder and at least one fluid passageway provided in the housing block. The plunger head may include a stop cushion assembly. The stop cushion assembly provides for a cushioned stop if the end of the piston head engages the fixed structure of the plunger assembly in the event of power loss.

A vehicle brake system includes a dual acting plunger assembly. The dual acting plunger assembly comprises a housing, an anti-rotation tube secured to a ball screw assembly, and a torque coupler. The torque coupler is attached between the housing and anti-rotation tube, wherein the torque coupler allows rotation between the housing and the anti-rotation tube.

Disclosed is an actuator of an electronic brake system including: a motor having a stator and a rotor for generating a rotational force by an electrical signal, the rotor having an accommodating space therein; a power conversion unit disposed in the accommodating space, and including a spindle rotated by a rotational force of the rotor and a nut coupled to the spindle to be linearly moved by rotation of the spindle; a piston coupled to move with the nut; and a sleeve coupled to one end of the rotor by a bearing so that the rotor is relatively rotatable and having an inner space communicating with the accommodating space and accommodating the piston so as to be able to move forward and backward.

A brake system includes first and second wheel brakes, a reservoir, and a brake pedal unit having a housing and a pair of output pistons slidably disposed in the housing. The output pistons generate brake actuating pressure during a manual push-through mode for actuating the first and second wheel brakes. The system further includes a plunger assembly having a housing having a motor driving an actuator, and a piston connected to the actuator. The piston pressurizes a chamber when the piston is moving in a first direction to provide fluid flow out of a first port and through a pair of parallel valves. The piston pressurizes a second chamber when the piston is moving in a second direction opposite the first direction to provide fluid flow out of a second port. The first and second ports are selectively in fluid communication with the wheel brakes.

Disclosed is an actuator of an electronic brake system including: a drive unit generating a power and including a motor having a stator and a rotor; a piston unit operated by the drive unit and including a piston reciprocating in a bore chamber provided in a piston housing to contain a fluid; a power transmission unit having one end coupled to the rotor and the other end coupled to the piston to convert a rotational motion of the rotor into a linear motion of the piston; a sensing magnet coupled to the power transmission unit to rotate along the motor; and a motor position sensor disposed coaxially with and spaced apart from the sensing magnet to sense a position of the motor based on the rotation of the sensing magnet.

Disclosed herein are an electric brake system and an operating method thereof. The electric brake system includes a master cylinder to discharge a pressurized medium in accordance with displacement of a brake pedal, a simulation device to provide a driver with a pedal feeling, a hydraulic pressure supply device to generate a hydraulic pressure by operating a hydraulic piston in accordance with an electrical signal output in response to the displacement of the brake pedal, and a hydraulic control unit to control a hydraulic pressure of the pressurized medium supplied to each wheel cylinder. The electric brake system may perform a normal mode, an abnormal mode, and an inspection mode.

A brake system for actuating a pair of front wheel brakes and a pair of second wheel brakes. The brake system includes a reservoir and a brake pedal unit having a housing with first and second pistons slidably disposed in the housing. The first and second pistons are operable during a manual push-through mode by actuation of a brake pedal connected to the brake pedal unit. The first and second pistons are movable to generate brake actuating pressure at first and second outputs for actuating the pair of front wheel brakes and the pair of rear wheel brakes. A first source of pressurized fluid actuates the pair of front wheel brakes and the pair of rear wheel brakes during a non-failure normal braking event. A first electronic control unit controls the first source of pressurized fluid. A second source of pressurized fluid is hydraulically connected to the brake pedal unit and actuates the brake pedal unit to cause movement of the first and second pistons for generating pressure at the first and second outputs. A second electronic control unit, separate from the first electronic control unit, controls the second source of pressurized fluid.

A brake fluid pressure control unit that can improve cost performance of a brake system is obtained. A brake system that includes such a brake fluid pressure control unit and a motorcycle are also obtained.

A brake fluid pressure control unit 50 includes: an inlet valve 21 provided in a primary channel 14; an outlet valve 22 provided in a secondary channel 15; a pressurizing/transferring mechanism 25 provided on a downstream side of the outlet valve 22 in the secondary channel 15 and pressurizing and transferring a brake fluid in the secondary channel 15; and a controller 51 for executing a fluid pressure control operation of the brake fluid in a wheel cylinder 13, and a power source of the pressurizing/transferring mechanism 25 is a drive mechanism 103 of the motorcycle 100, the drive mechanism 103 being driven in a state where the fluid pressure control operation by the controller 51 is not executed.

A piston pump assembly for a hydraulic power vehicle braking system including an electric motor, a planetary gear set, a helical gear, and a piston which is displaceable in a cylinder. To prevent the piston from rotating in the cylinder, cylinder pins are situated in grooves at an inner side of the cylinder and engage with the recesses in a flange of the piston. Due to reshaping, the grooves are closed at one end, so that the cylinder pins are axially secured.

A brake system may include an actuating device, in particular a brake pedal; a first piston-cylinder unit having two pistons subjecting the brake circuits to a pressure medium via a valve device, wherein one of the pistons can be actuated by the actuation device; a second piston-cylinder unit having an electric motor drive, a transmission at least one piston to supply at least one of the brake circuits with a pressure medium via a valve device; and a motor pump unit with a valve device to supply the brake circuits with a pressure medium. The brake system may also include a hydraulic travel simulator with a pressure or working chamber which is connected to the first piston-cylinder unit.