Control system and control method of a variable displacement hydraulic pump wherein the system includes a detection sensor for detection of the actually set displacement and a control unit for current control of a couple of solenoids controlling displacement increase and decrease.

Control system and control method of a variable displacement hydraulic pump wherein the system includes a detection sensor for detection of the actually set displacement and a control unit for current control of a couple of solenoids controlling displacement increase and decrease.

A hydraulic system includes: a cylinder that moves a moving object in a vertical direction by extension and retraction of a rod; a first bidirectional pump connected to a head-side chamber of the cylinder by a first supply/discharge line; a second bidirectional pump connected to a rod-side chamber of the cylinder 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 a servomotor 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.

The present disclosure relates to an adjusting device for adjusting the swash plate of an axial piston machine comprising an adjusting piston, which is connected to the swash plate of the axial piston machine via an adjusting lever, and a regulator for adjusting the adjusting pressure acting on the adjusting piston in dependence on a control force acting on a control piston of the regulator, wherein the adjusting piston is connected to the control piston via a feedback spring. In accordance with the present disclosure the feedback spring is at least partly received in a pot-shaped recess of the control piston.

The present disclosure relates to an adjusting device for adjusting the swash plate of an axial piston machine comprising an adjusting piston, which is connected to the swash plate of the axial piston machine via an adjusting lever, and a regulator for adjusting the adjusting pressure acting on the adjusting piston in dependence on a control force acting on a control piston of the regulator, wherein the adjusting piston is connected to the control piston via a feedback spring. In accordance with the present disclosure the feedback spring is at least partly received in a pot-shaped recess of the control piston.

A variable stroke high pressure pump is disclosed. The pump uses a wobble plate design with dynamically variable tilt to provide continuous adjustment of pump stroke length and output. Dynamically variable tilt is accomplished using a linearly actuated tilt thruster rotationally coupled to the drive shaft to maintain a selected tilt of the wobble plate through the rotation of the wobble plate.

A method is for producing, for a hydraulic machine having an actuator, a setpoint-value trajectory satisfying predefined limitations in order to influence an output variable of the hydraulic machine. A trajectory of unlimited setpoint values is fed to a trajectory planning function, which produces the setpoint-value trajectory from the trajectory of unlimited setpoint values. In the trajectory planning function, the trajectory of unlimited setpoint values is differentiated at least twice in order to obtain a trajectory of unlimited setpoint values that is differentiated n times. In the trajectory planning function, at least one limitation is applied to the differentiated trajectory of unlimited setpoint values in order to obtain a differentiated trajectory of limited setpoint values. The differentiated trajectory of limited setpoint values is fed to a filter integrator chain in order to obtain the setpoint-value trajectory.

The present invention provides a low-cost detachment determining device capable of determining whether or not an electromagnetic valve-equipped device has been detached. The detachment determining device determines whether or not at least a part of an electromagnetic valve-equipped device included in an industrial machine, such as a construction machine or an industrial vehicle, has been detached from the industrial machine, the electromagnetic valve-equipped device being a hydraulic device equipped with an electromagnetic valve. The detachment determining device includes: an electrical characteristic detecting portion configured to output a detection signal to the electromagnetic valve-equipped device and detect an electrical characteristic of the electromagnetic valve-equipped device based on the detection signal; and a detachment determining portion configured to determine, based on a plurality of electrical characteristics detected at different time points by the electrical characteristic detecting portion, whether or not at least a part of the electromagnetic valve-equipped device has been detached.

An electronic angle adjustment mechanism for a pump and a motor generally includes a base and a linear actuator. The base has an upper portion mounted to a motor, a lower portion mounted to a pump, and a hinge for pivotably moving the upper base portion in relation to the lower base portion. The linear actuator is mounted to on an attachment plate that also attaches the motor to the upper base portion. The linear actuator can drive a flexible member or connect to a gear wheel or worm screw to pivot about the hinge and change an angle between the upper and lower base portions.

A variable stroke high pressure pump is disclosed. The pump uses a wobble plate design with dynamically variable tilt to provide continuous adjustment of pump stroke length and output. Dynamically variable tilt is accomplished using a linearly actuated tilt thruster rotationally coupled to the drive shaft to maintain a selected tilt of the wobble plate through the rotation of the wobble plate.