A hydraulic assembly for a vehicle transmission includes a hydraulic pump for providing a system pressure within a hydraulic circuit, a pressure accumulator for temporarily supplying pressure to the hydraulic circuit, and a valve assembly for charging the pressure accumulator after a predetermined pressure threshold value of the system pressure has been reached or exceeded. The valve assembly is hydraulically connected between the pump and the pressure accumulator.

The present invention relates to an electrohydrostatic system having a hydraulic cylinder comprising a first cylinder chamber and a second cylinder chamber. Furthermore, the electrohydrostatic system has a fluid hydraulic supply device for providing a hydraulic fluid, a fluid hydraulic motor pump unit, designed to provide a fluid hydraulic volume flow in order to move the hydraulic cylinder. A motor control device is designed to provide a rated current for an electrical drive of the fluid hydraulic motor pump unit. Moreover, the electrohydrostatic system has at least one fluid hydraulic safety valve, which on a first valve side is connected to one of the cylinder chambers of the hydraulic cylinder and on a second valve side is connected to the fluid hydraulic motor pump unit. The fluid hydraulic safety valve can be bridged via a bypass connection with a fixed orifice plate, wherein the bypass connection is connected to the first valve side and to the second valve side of the at least one fluid hydraulic safety valve. Moreover, the electrohydrostatic system has a pressure sensor that is connected to one of the cylinder chambers of the hydraulic cylinder. The pressure sensor is designed to detect a fluid hydraulic pressure on one of the cylinder chambers and, according to the detected fluid hydraulic pressure, to provide an enabling signal for the motor control device to provide the rated current for the electrical drive of the fluid hydraulic motor pump unit.

In an implementation, a hydraulically-powered robot has a first body portion having a first internal volume, a second body portion having a second internal volume, and a plurality of hydraulic hoses. The second body portion is rotatably coupled to the first body portion. Each hydraulic hose of the plurality of hydraulic hoses includes a respective first hose portion positioned within the first internal volume of the first body portion and a respective second hose portion positioned within the second internal volume of the second body portion. The plurality of hydraulic hoses is arranged in a helical configuration about an axis that extends from the first internal volume of the first body portion to the second internal volume of the second body portion. A path of the helical configuration of the plurality of hydraulic hoses may traverse a restricted space between the first body portion and the second body portion.

In an implementation, a hydraulically-powered robot has a first body portion having a first internal volume, a second body portion having a second internal volume, and a plurality of hydraulic hoses. The second body portion is rotatably coupled to the first body portion. Each hydraulic hose of the plurality of hydraulic hoses includes a respective first hose portion positioned within the first internal volume of the first body portion and a respective second hose portion positioned within the second internal volume of the second body portion. The plurality of hydraulic hoses is arranged in a helical configuration about an axis that extends from the first internal volume of the first body portion to the second internal volume of the second body portion. A path of the helical configuration of the plurality of hydraulic hoses may traverse a restricted space between the first body portion and the second body portion.

A fluid control device includes a housing partitioned into an input chamber and an output chamber by a housing land portion extending on the radially inner side, a spool arranged inside the housing and provided with a spool land portion that is configured to reciprocatively slide with respect to the housing land portion and that extends on a radially outer side of the spool, and a biasing member configured to bias the spool toward a valve closing position, wherein upon receiving drive force from an exterior, the spool is moved against bias force of the biasing member, and the input chamber and the output chamber communicate with each other, the spool includes a large diameter portion arranged in the input chamber and having a larger diameter than the spool land portion, and the large diameter portion and the housing land portion form a poppet valve structure.

A combined valve for insertion into an elongated bore of a power unit body of a hydraulic power unit may have an elongated carrier for receiving a relief and a check valve. The valve may also have a register arranged at a first axial position of a longitudinal axis of the carrier for calibration of the relief valve. The valve may also have a check valve coupled to the carrier at a second axial position along the longitudinal axis of the carrier. The valve may also have a relief valve coupled to the carrier at a third axial position along the longitudinal axis of the carrier. A minimal distance between the first and the second axial position may be less than a minimal distance between the first and the third axial position.

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 power transmission device includes a torque converter device, a first hydraulic pump, a first oil channel, a second oil channel, a third oil channel, a second pressure control valve, and a controller. The torque converter device has a torque converter and a lock-up clutch. The first oil channel supplies hydraulic fluid from the first hydraulic pump to the torque converter. The second oil channel drains hydraulic fluid from the torque converter. The third oil channel communicates with the first oil channel and the second oil channel. The second pressure control valve is disposed in the third oil channel. The controller sets the second pressure control valve to an open state when the lock-up clutch is in an engaged state.

A power transmission device includes a torque converter device, a first hydraulic pump, a first oil channel, a second oil channel, a third oil channel, a second pressure control valve, and a controller. The torque converter device has a torque converter and a lock-up clutch. The first oil channel supplies hydraulic fluid from the first hydraulic pump to the torque converter. The second oil channel drains hydraulic fluid from the torque converter. The third oil channel communicates with the first oil channel and the second oil channel. The second pressure control valve is disposed in the third oil channel. The controller sets the second pressure control valve to an open state when the lock-up clutch is in an engaged state.

A counter pressure valve arrangement for controlling a pressure level of a hydraulic fluid in a return line from a hydraulic actuator arrangement. The counter pressure valve arrangement comprises a counter pressure valve having: a moveable valve member; a counter pressure regulating port configured for being connected to the hydraulic actuator arrangement via the return line; a tank port configured for being connected to a tank or low pressure reservoir for storing low pressure hydraulic fluid; and a pump port configured for being connected to a source of pressurised hydraulic fluid. A first position of the valve member effects fluid communication between the pump port and the counter pressure regulating port for supplying pressurised hydraulic fluid to the return line, and a second position of the valve member effects fluid communication between the counter pressure regulating port and the tank port for discharging hydraulic fluid from the return line to the tank.