An electro-hydrostatic drive for realizing a rapid movement during a rapid movement phase, a force-building movement during a force-building movement phase. The apparatus comprises a hydro-machine with variable volume and/or rotational speed, driven by an electric motor, for providing a volume-stream of a hydraulic fluid, a first cylinder with a piston chamber, an rod chamber, and a plunger rod, a reservoir, a pressure source, a relief valve, a check valve, a fluid connection between the piston chamber and the hydro-machine, a fluid connection between the rod chamber and the hydro-machine, a fluid connection between the piston chamber and the reservoir, a fluid connection between the rod-chamber-side port of the hydro-machine and the reservoir, a fluid connection, through the relief valve, between the reservoir and the pressure source. The relief valve is for pressure safety of the reservoir, and the check valve has a fluid connection from the pressure source to the rod-chamber-side port of the hydro-machine, during the rapid movement phase, a first part of the hydraulic fluid is piped through the fluid connection between the piston chamber and the hydro-machine and the fluid connection between the rod chamber and the hydro-machine, and a second part of the hydraulic fluid communicates through the fluid connection between the piston chamber and the reservoir, during the force-building movement phase, a first part of the hydraulic fluid is piped through the fluid connection between the piston chamber and the hydro-machine and the fluid connection between the rod chamber and the hydro-machine, and a second part of the hydraulic fluid is piped through the fluid connection between the rod-chamber-side port of the hydro-machine and the reservoir.

A pneumatic remote actuating device includes an actuator block, an actuated block and a tube connecting the actuator block to the actuated block. The actuator block includes an enclosure that can be mounted on a generally flat surface. A pushbutton protrudes in front of the actuator block. Depressing the pushbutton causes an increase of pressure within an internal chamber of the enclosure. This pressure is transmitted from the actuator block, via the tube, to the actuated block. The actuated block comprises its own enclosure that can be mounted on a generally flat surface to place the actuated block in an overlapping position over an external pushbutton. The pressure transmitted from the actuator block to the actuated block causes a displacement of a pusher mounted in the enclosure of the actuated block. As a result, the pusher actuates the external pushbutton.

A hydraulic system for a mobile rescue stretcher has a hydraulic cylinder, with first and second working chambers, a tank and pump. The first and second chambers are connected to the pump via first and second line arrangements, respectively, and can be pressurized by the pump. Hydraulic fluid flows out of the first chamber via the first line arrangement when pressure is applied to the second chamber. The first line arrangement has a first check valve which opens when pressure is applied to the second line arrangement. Hydraulic fluid flows out of the second chamber via the second line arrangement when pressure is applied to the first chamber. The second line arrangement has a first branch line connected to the pump and a second branch line connected to the tank. A pressure valve in the second branch line opens when pressure is applied to the second line arrangement.

A steering system for a trailing or leading axle of a vehicle includes a steering angle sensor for measuring a steering angle of wheels of a front axle of the vehicle, a driving speed sensor for measuring a driving speed of the vehicle, an electric motor that drives a hydraulic pump, and a working cylinder connected to the hydraulic pump for steering the wheels of the trailing axle. The system also includes a control device that determines a trailing angle of wheels on the trailing axle of the vehicle and actuates the electric motor in a corresponding manner. The working cylinder has a center position borehole via which hydraulic fluid is released from the working cylinder. A piston closes the center position borehole in the straight-ahead position of the wheels of the trailing axle. The center position borehole can only be closed by a piston seal of the piston.

To provide a traveling control mechanism and a traveling control method capable of controlling a traveling mechanism taking into consideration operation contents of a remote control valve. The problem is solved by a traveling control mechanism comprising a remote control valve (21, 22, 23, 24), a pressure adjusting solenoid valve (61, 62), a setting mechanism (70), and a controller (60). The traveling mechanism (8) allows a traveling speed to be switched between a high speed and a low speed in accordance with an operation amount of the remote control valve (21, 22, 23, 24). An HST circuit (30) is provided with a pump (31, 32) and a traveling motor (33), the pump (31, 32) connects to a pilot line (41, 42, 43, 44) allowing a hydraulic oil supplied from the remote control valve (21, 22, 23, 24) to flow therethrough, a pressure sensor (45) is attached to the pilot line (41, 42, 43, 44), and a rotation sensor (65) is attached to the traveling motor (33). The controller (60) controls a pressure of the hydraulic oil supplied from the remote control valve (21, 22, 23, 24) independently of a manual operation of the remote control valve (21, 22, 23, 24), on the basis of a setting signal, a pressure signal, and a rotation speed signal. The remote control valve (21, 22, 23, 24) controls a flow rate of the hydraulic oil discharged from the pump (31, 32) by changing or keeping constant the pressure inside the pilot line (41, 42, 43, 44).

A hydraulic system includes: a cylinder in which an interior of a tube is divided by a piston into a first pressure chamber and a second pressure chamber; a first bidirectional pump connected to the first pressure chamber by a first supply/discharge line; a second bidirectional pump connected to the second pressure chamber by a second supply/discharge line and coupled to the first bidirectional pump in a manner enabling torque to be transmitted between the first and second bidirectional pumps; a relay line connecting the first and second bidirectional pumps such that a hydraulic liquid discharged from one of the first and second bidirectional pumps is introduced into the other of the first and second bidirectional pumps; and an electric motor that drives the first or second bidirectional pump. At least one of the first and second bidirectional pumps is a variable displacement pump whose delivery capacity per rotation is freely variable.

An injection moulding system, water jet cutting machine or other industrial system has a synthetically controlled variable displacement fluid working machine which outputs hydraulic fluid to one or more fluid consumers, such as rams or hydraulic motors, through hydraulically stiff fluid retaining volumes and receives hydraulic fluid back from one or more fluid consumers through the same or other said hydraulically stiff fluid retaining volumes. Individual piston cylinder assemblies can be allocated to different outputs. There may be no valve between the machine and the consumers. A working chamber of the machine can be caused to undergo a motoring cycle to enable the machine to output more power than is received from a motor driving the machine. An accumulator can be used to provide a source of hydraulic compliance. The machine can be controlled using pressure control, flow control, feed forward control or variable power/variable power limit control.

An injection moulding system, water jet cutting machine or other industrial system has a synthetically controlled variable displacement fluid working machine which outputs hydraulic fluid to one or more fluid consumers, such as rams or hydraulic motors, through hydraulically stiff fluid retaining volumes and receives hydraulic fluid back from one or more fluid consumers through the same or other said hydraulically stiff fluid retaining volumes. Individual piston cylinder assemblies can be allocated to different outputs. There may be no valve between the machine and the consumers. A working chamber of the machine can be caused to undergo a motoring cycle to enable the machine to output more power than is received from a motor driving the machine. An accumulator can be used to provide a source of hydraulic compliance. The machine can be controlled using pressure control, flow control, feed forward control or variable power/variable power limit control.

A hydraulic pressure generating device includes a base body having a master cylinder configured to generate a brake hydraulic pressure and a slave cylinder configured to generate a brake hydraulic pressure. The base body is provided with a motor configured as a driving source for the slave cylinder and a control device configured to control the motor. A motor shaft of the motor, a cylinder axis of the master cylinder, and a cylinder axis of the slave cylinder are disposed in parallel with each other. Then a virtual plane including the cylinder axis of the master cylinder is set as a reference plane, a housing of the control device is disposed on one side of the reference plane and the motor is disposed on the other side of the reference plane.

A linear actuator system includes a linear actuator and at least one proportional control valve and at least one pump connected to the linear actuator to provide fluid to operate the linear actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The linear actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover and concurrently establishes an opening of the at least one proportional control valve to adjust at least one of a flow and a pressure in the linear actuator system to an operational set point.