A hydraulic tank has an elastically deformable membrane defining a variable compensation chamber within the tank. The membrane has a fixed perimeter portion and a thrusting portion. A perimeter inlet portion is arranged between the perimeter fixing portion and the thrusting portion. In the condition of minimum expansion of the compensation chamber, the thrusting portion is completely arranged between the perimeter inlet portion of the membrane and a wall of the tank.

A piston-cylinder unit includes a piston delimiting at least one working chamber, in which a first seal for sealing at least one first working chamber is arranged either between the piston and cylinder or between a plunger connected to the piston and the cylinder. A second seal is arranged between the first seal and the first working chamber, and the piston-cylinder unit further includes a first channel arranged in the wall of the cylinder or in the piston, which joins the first seal and the second seal in the inner chamber of the cylinder. The first channel and/or a hydraulic line connected thereto may have a throttle device and/or a valve device. An electronic control and regulating device may have a diagnosis or monitoring function for a possible defect or failure of a seal. Multiple hydraulic devices may have such piston-cylinder units and respective control and such regulating devices.

A valve arrangement is inserted between a master brake cylinder and a reservoir in a housing of an electrohydraulic motor vehicle brake system which can be activated both by a vehicle driver and independently of the vehicle driver. The valve arrangement can be acted on by a volume flow which can be conveyed by a linear actuator in the direction of a pedal travel simulator, the working chamber of the pedal travel simulator being connected to the master brake cylinder, wherein, for the purpose of simplified construction and actuation, the valve arrangement has a hydraulically actuable non-return valve and a fixed diaphragm arranged parallel to the non-return valve. The non-return valve is arranged together with the fixed diaphragm in a valve carrier which is fastened to a closure plug which closes the housing of the motor vehicle brake system.

A valve arrangement is inserted between a master brake cylinder and a reservoir in a housing of an electrohydraulic motor vehicle brake system which can be activated both by a vehicle driver and independently of the vehicle driver. The valve arrangement can be acted on by a volume flow which can be conveyed by a linear actuator in the direction of a pedal travel simulator, the working chamber of the pedal travel simulator being connected to the master brake cylinder, wherein, for the purpose of simplified construction and actuation, the valve arrangement has a hydraulically actuable non-return valve and a fixed diaphragm arranged parallel to the non-return valve. The non-return valve is arranged together with the fixed diaphragm in a valve carrier which is fastened to a closure plug which closes the housing of the motor vehicle brake system.

A sealing element for sealing a pressure chamber is provided in a master cylinder for a clutch or brake system. The sealing element has a sealing lip for sealing a feed of hydraulic fluid from a reservoir mounted on a housing of the master cylinder into the pressure chamber and has a sealing structure for sealing the pressure chamber from the surroundings of the pressure chamber.

A sealing element for sealing a pressure chamber is provided in a master cylinder for a clutch or brake system. The sealing element has a sealing lip for sealing a feed of hydraulic fluid from a reservoir mounted on a housing of the master cylinder into the pressure chamber and has a sealing structure for sealing the pressure chamber from the surroundings of the pressure chamber.

A brake pedal unit includes a housing defining a bore formed therein. An input piston is slidably disposed in the bore. The input piston is connected to a brake pedal such that engagement of the brake pedal causes movement of the input piston within the bore of the housing of the brake pedal unit. The brake pedal unit is defined to be in an at rest position when the brake pedal in not engaged causing movement of the input piston. A primary piston is slidably disposed in the bore for pressurizing a primary chamber. A primary passageway permits fluid communication between the primary chamber and the reservoir, wherein fluid flow through the primary passageway is blocked when the brake pedal unit is in the rest position. A secondary piston is slidably disposed in the bore for pressurizing a secondary chamber. A secondary passageway permits fluid communication between the secondary chamber and the reservoir, wherein fluid flow through the secondary passageway is blocked when the brake pedal unit is in the rest position.

A drilling of a hydraulic unit of a service brake assembly of a vehicle hydraulic-power brake system.

A non-return valve for a vehicle hydraulic-power brake system. The non-return valve has a valve-seat part in the form of an apertured disk, onto which is pressed a valve cage in which a valve ball is disposed as shut-off member and a helical compression spring is disposed as valve spring. A bowl-shaped filter is secured in a depression in the valve-seat part opposite the valve cage.

In order to provide a master cylinder, in particular for a clutch system, an actuating system or a braking system of a vehicle, which enables secure sealing of the cylinder chamber relative to the outside, as well as a reliable flow of hydraulic medium into the cylinder chamber, it is proposed that the piston comprises a first section which has a cylindrical lateral surface and a second section which has at least one region which is set back radially inwardly with respect to the cylindrical lateral surface of the first section, wherein at least one set-back region extends to an end of the piston and wherein the first and second sections are arranged on the piston in such a way that in an actuating position of the piston, the main sealing element in the first section of the piston abuts in sealing manner thereagainst and in the pressure equalization position of the piston, in the second section of the piston between the piston and the main sealing element, at least one gap is formed, through which hydraulic medium can flow along the piston from the supply chamber into the cylinder chamber in order to equalize the pressure.