Abstract: A motor vehicle pump arrangement has a first pump and a second pump, and an electric motor for driving the two pumps. The electric motor is drive-connected fixedly to the first pump and connected via a clutch arrangement to the second pump, in such a way that the first pump can be driven on its own and the first and second pump can be driven together. The first pump is configured as a reversible pump which can be operated in two rotational directions. A valve arrangement generates a uniformly directed fluid volumetric flow which is independent of the rotational direction being provided for the first pump in a fluid circuit. The clutch arrangement is configured as a freewheeling clutch, via which the electric motor is drive-connected to the second pump.

Abstract: A motor vehicle pump arrangement has a first pump and a second pump, and an electric motor for driving the two pumps. The electric motor is drive-connected fixedly to the first pump and connected via a clutch arrangement to the second pump, in such a way that the first pump can be driven on its own and the first and second pump can be driven together. The first pump is configured as a reversible pump which can be operated in two rotational directions. A valve arrangement generates a uniformly directed fluid volumetric flow which is independent of the rotational direction being provided for the first pump in a fluid circuit. The clutch arrangement is configured as a freewheeling clutch, via which the electric motor is drive-connected to the second pump.

Abstract: In a method for starting an internal combustion engine of a motor vehicle which is connected to a transmission via a starting device and operated in a start/stop operating mode, a hydraulic medium is fed to the starting device via a valve device by a hydraulic pump. Before and during starting of the internal combustion engine by use of a starter, a control unit actuates the valve device in such a way that the valve device enables delivery of the hydraulic medium to the starting device. The control unit actuates the hydraulic pump in such a way that during the starting of the internal combustion engine the hydraulic pump delivers the hydraulic medium directly into the starting device in order to bring about a mechanical operative connection between the internal combustion engine and the transmission by the starting device.

Abstract: A hydraulic linear drive, particularly a hydraulic transmission actuator, having a piston/cylinder unit, in which an actuating piston longitudinally displaceably arranged in the cylinder housing divided into at least two pressure chambers which can be acted upon by hydraulic oil by way of control conduits. A piston rod is connected with the actuating piston, and a sealing element is arranged on the actuating piston to seal off the two pressure chambers from one another. The actuating piston has a two-piece construction and consists of a first and a second piston part between whose facing faces, a sealing element is arranged.

Abstract: A hydraulic transmission actuator has a piston/cylinder unit in which an actuating piston longitudinally displaceably arranged in the cylinder housing divides the cylinder chamber into at least two pressure chambers which can be acted upon by hydraulic oil by way of control conduits. A piston rod is connected with the actuating piston, and a sealing element is arranged on the actuating piston. The sealing element seals off the two pressure chambers from one another. The diameter of the cylinder housing is locally reduced for increasing the radial contact pressure force of the sealing element with respect to the interior cylinder wall.

Abstract: A hydraulic linear drive for a hydraulic vehicle transmission actuator has a piston/cylinder unit in which an adjusting piston is arranged so it is longitudinally displaceable in a cylinder housing and subdivides the cylinder space into at least two pressure spaces which can receive hydraulic oil through control lines. The optional pressure action on the two pressure spaces is controllable by a shift valve. A connecting line is provided between the two control lines leading to the pressure spaces and a control valve is provided for optionally releasing or blocking the connecting line to further control the pressure force acting on the piston.

Abstract: A hydraulic linear drive, in particular for a hydraulic transmission actuator, has a piston/cylinder unit in which an adjusting piston is situated so that it is longitudinally displaceable in a cylinder housing and divides a cylinder space into at least two pressure spaces. The pressure spaces can be acted upon by hydraulic oil via controllable pressure supply through hydraulic lines. A sealing ring is situated on the adjusting piston or on the cylinder housing for sealing, the two pressure spaces with respect to one another. The sealing ring is accommodated in a ring groove on the cylinder housing so as to seal with its inside against the adjusting piston. A sealing pressure supply system communicates hydraulic oil to the outside of the sealing ring so as to control the sealing pressure of the sealing ring on the piston surface.

Abstract: A hydraulic linear drive, particularly a hydraulic transmission actuator, having a piston/cylinder unit, in which an actuating piston longitudinally displaceably arranged in the cylinder housing divided into at least two pressure chambers which can be acted upon by hydraulic oil by way of control conduits. A piston rod is connected with the actuating piston, and a sealing element is arranged on the actuating piston to seal off the two pressure chambers from one another. The actuating piston has a two-piece construction and consists of a first and a second piston part between whose facing faces, a sealing element is arranged.

Abstract: A hydraulic transmission actuator has a piston/cylinder unit in which an actuating piston longitudinally displaceably arranged in the cylinder housing divides the cylinder chamber into at least two pressure chambers which can be acted upon by hydraulic oil by way of control conduits. A piston rod is connected with the actuating piston, and a sealing element is arranged on the actuating piston. The sealing element seals off the two pressure chambers from one another. The diameter of the cylinder housing is locally reduced for increasing the radial contact pressure force of the sealing element with respect to the interior cylinder wall.

Abstract: A hydraulic linear drive for a hydraulic vehicle transmission actuator has a piston/cylinder unit in which an adjusting piston arranged so it is longitudinally displaceable in a cylinder housing and subdivides the cylinder space into at least two pressure spaces which can receive hydraulic oil through control lines. The optional pressure action on the two pressure spaces is controllable by a shift valve. A connecting line is provided between the two control lines leading to the pressure spaces and a control valve is provided for optionally releasing or blocking the connecting line to further control the pressure force acting on the piston.

Abstract: A hydraulic linear drive, in particular for a hydraulic transmission actuator, has a piston/cylinder unit in which an adjusting piston is situated so that it is longitudinally displaceable in a cylinder housing and divides a cylinder space into at least two pressure spaces. The pressure spaces can be acted upon by hydraulic oil via controllable pressure supply through hydraulic lines. A sealing ring is situated on the adjusting piston or on the cylinder housing for sealing, the two pressure spaces with respect to one another. The sealing ring is accommodated in a ring groove on the cylinder housing so as to seal with its inside against the adjusting piston. A sealing pressure supply system communicates hydraulic oil to the outside of the sealing ring so as to control the sealing pressure of the sealing ring on the piston surface.