A piston pump is configured to convey pressure medium in a pressure medium circuit, in particular in a braking circuit of a motor vehicle braking system that may be electronically controlled to counteract slip. The pump piston delimits an operating chamber and is received in a displaceable manner in a pump cylinder and may be driven to produce a stroke movement that goes back and forth between two reversing positions. The operating chamber may be connected in a controllable manner to a pump inlet or outlet. A pressure medium connection is provided from the pump outlet to the operating chamber, said pressure medium connection is controllable in dependence upon a relative position of the pump piston with respect to the first reversing position. Pressure pulsations of the piston pump are prevented and the operating noise is reduced.

Provided is a novel pressure pulsation reducing device of a hydraulic system that reduces a stress generated in a metal diaphragm and is excellent in durability. A plurality of concentric recess portions projecting toward an interior space of a pulsation damping member is formed on one of metal diaphragms, and a plurality of concentric recess portions projecting toward the interior space of the pulsation damping member is formed on the other metal diaphragm likewise. When a predetermined pressure is applied to the metal diaphragms, at least one recess portion of one of the metal diaphragms and at least one recess portion of the other metal diaphragm are in contact with each other.

A device for choking a fluid flow, with a pot-like base body, in the base of which a first passage opening is arranged, and a closing body guided axially moveably in the pot-like base body against a spring force of a spring element and having a second passage opening that forms a static choke point with a predefined fixed opening cross section. The closing body in combination with the spring element and the first passage opening forms a dynamic choke point with a dynamic opening cross section that is variably adjustable depending on a pressure difference.

The invention aims to provide a motor module in which the number of components is reduced and the number of steps required for assembly is reduced, and an ABS hydraulic unit in which the motor module is embedded. Provided is a motor module including a motor and a planetary gear mechanism which is attached to an output shaft of the motor. The motor module includes a fixing portion that integrally fixes the motor and the planetary gear mechanism. The fixing portion fixes the motor by inwardly clamping the motor and fixes an internal gear of the planetary gear mechanism.

Provided is a brake apparatus having a detachable pump housing. The brake apparatus having a detachable pump housing includes a master cylinder that receives an operating force of a pedal, a main housing in which the master cylinder is accommodated and a through-hole is formed at one side thereof, a motor that provides a driving force, a pump piston that is accommodated in the main housing, and moves in and out of the main housing through the through-hole by receiving the driving force from the motor, a gear unit that converts the driving force of the motor into a linear motion and transmits the linear motion to the pump piston, and a pump housing in which the pump piston is accommodated and an opening is formed at one side thereof, and that is detachably fastened to the main housing such that the opening communicates with the through-hole.

A hydraulic unit of a vehicle brake system includes at least one pump element that is driven via an eccentric, which is enclosed by an eccentric chamber. The hydraulic unit also includes a vacuum pump that is configured to maintain a vacuum in the eccentric chamber while the hydraulic unit is in operation.

Disclosed is a piston pump for a brake system installed in a bore of a modulator block communicating with an inlet port and a discharge port, wherein the piston pump includes: a cylinder unit provided to reciprocate within the bore; a piston unit having one end fixed and the other end dividing the inside of the cylinder unit into a first chamber and a second chamber and configured to expand or reduce the internal spaces of the first chamber and the second chamber by reciprocating movement of the cylinder unit; a first inlet valve installed in the cylinder unit to open and close an one-way flow of fluid from the inlet port to the first chamber; a second inlet valve installed in the cylinder unit to open and close an one-way flow of fluid from the inlet port to the second chamber; and an outlet valve to open and close an one-way flow of fluid from the first chamber or the second chamber to the discharge port.

A piston pump, in particular as a pressure generator in an electronically slip-controllable vehicle brake system, includes a pump cylinder, a drivable piston, a pump working chamber, a valve space, and a valve. The drivable piston is slidably accommodated in the pump cylinder. The pump working chamber is bounded by the piston and the pump cylinder. The valve controls a supply of pressure medium to the pump working chamber. The valve has a conical valve seat and a closing element having a domed shell section that interacts with the valve seat. The valve seat surrounds the valve space, into which the closing element plunges, at least up to an imaginary center point of the domed shell section, when the valve seat is closed or open.

A pump housing of a motor vehicle hydraulic unit is disclosed. The pump housing has at least one side surface, at least one main cylinder connection opening, at least one pump element opening and a connecting line which connects the at least one main cylinder connection opening to the at least one pump element opening. The pump housing is designed as a blind bore into the pump housing, and the blind bore of the connecting line extends from the at least one side surface initially through the at least one pump element opening and subsequently into the at least one main cylinder connection opening.

A device for choking a fluid flow includes a pot-like base body, in the base of which a first passage opening is arranged, and a closing body guided axially moveably in the pot-like base body against a spring force of a spring element and having a second passage opening that forms a static choke point with a predefined fixed opening cross section. The closing body in combination with the spring element and the first passage opening forms a dynamic choke point with a dynamic opening cross section that is variably adjustable depending on a pressure difference.