Presented herein are systems and methods for attenuating certain pulsations in a hydraulic system comprising a pump and a hydraulic actuator. In certain aspects, an accumulator comprising an internal volume that is divided into a working chamber and a contained chamber may be utilized to at least partially attenuate propagation of certain pulsations in the system. The working chamber may be fluidically coupled to the pump via a first flow path and fluidically coupled to a chamber of the actuator via a second flow path. The system may be designed such that a first inertance of the first flow path is greater than a second inertance of the second flow path. Additionally or alternatively, the system may be designed such that a resonance associated with the first inertance and a compliance of the accumulator may occur at a resonance frequency of less than 90 Hz.

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).

This clutch actuator includes a hydraulic pressure generating mechanism (51) configured to operate a clutch (26) to provide a connected state or a disconnected state, a motor (52) configured to generate a rotary driving force for driving the hydraulic pressure generating mechanism (51) to a driving shaft (52a), a transmission mechanism (54) configured to transmit the rotary driving force generated in the driving shaft (52a) of the motor (52) to a driven member (54b) parallel to the driving shaft (52a) in an axial direction and disposed coaxially with a cylinder main body (51a), and a conversion mechanism (55) configured to convert the rotary driving force transmitted to the driven member (54b) into a reciprocal driving force of a piston (51b) in a stroke direction, wherein the hydraulic pressure generating mechanism (51), the motor (52), the transmission mechanism (54) and the conversion mechanism (55) are integrated as a unit.

A system for imparting motion of an object includes: (1) at least one first hydrostatic actuator; (2) a hydraulic transmission conduit; and (3) at least one second hydrostatic actuator. The first hydrostatic actuator is connected to the second hydrostatic actuator via the hydraulic transmission conduit, such that an input displacement applied to the first hydrostatic actuator is transmitted via the hydraulic transmission conduit to the second hydrostatic actuator to impart motion of the object.

A system for imparting motion of an object includes: (1) at least one first hydrostatic actuator; (2) a hydraulic transmission conduit; and (3) at least one second hydrostatic actuator. The first hydrostatic actuator is connected to the second hydrostatic actuator via the hydraulic transmission conduit, such that an input displacement applied to the first hydrostatic actuator is transmitted via the hydraulic transmission conduit to the second hydrostatic actuator to impart motion of the object.

The present invention relates to a servo hydraulic press for sheet metal forming. The press comprises a hydraulic cylinder, at least two servo motors and at least two pumps for supplying pressurized fluid to the hydraulic cylinder, where each servo motor drives at least one pump. The servo motors are operable at variable speed, and the first servo motor and first pump are operable in an opposite direction to the second servo motor and the second pump. With this arrangement, the servo hydraulic press may be operated at low speed without causing damage to the pumps or motors.

A hydraulic actuator includes a hollow tube that has a first opening at a first end of the hollow tube and that has a second opening at a second end of the hollow tube. The hollow tube contains hydraulic fluid. A moveable magnet moves within hollow tube as a result of a magnetic field within the hollow tube. A magnetic field source located outside the hollow tube creates the magnetic field within the hollow tube. When the moveable magnet moves to the first end of the hollow tube, a first piston pushes hydraulic fluid out of the first opening. When the moveable magnet moves to the second end of the hollow tube a second piston pushes hydraulic fluid out of the second opening.

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.

A connecting and disconnecting device of a clutch includes a clutch pedal, a clutch cylinder, a depressing force transmission mechanism, and an actuator. The depressing force transmission mechanism includes a separation mechanism that connects and disconnects a depressing force transmission path of the depressing force transmission mechanism, the separation mechanism includes an input piston to which the depressing force from the clutch pedal is input, an output piston for outputting a clutch operating hydraulic pressure to the clutch cylinder, a first oil chamber provided between the input piston and the output piston, and an electromagnetic valve provided to make a connection or disconnection between the first oil chamber and a reservoir tank connected to the first oil chamber, and the actuator is connected to transmit power to the output piston of the separation mechanism.

A servo regulator includes a servo piston coupled with a swash plate, a pressure chamber provided to face an end portion of the servo piston, a spool configured to control a pressure in the pressure chamber by being moved by a solenoid, a biasing member configured to bias the spool against a thrust of the solenoid, and a feedback portion configured to change a biasing force of the biasing member in accordance with tilting of the swash plate, wherein the feedback portion is coupled with the swash plate via the servo piston.