Hydraulic systems and associated methods configured to reduce leakage past a spool valve when the system is in a neutral state. Leakage reduction is achieved by shifting the spool valve within the spool bore. The shifting direction can depend on whether the system has a relatively high load or a relatively low load in the neutral state. The amount of shifting can depend on the pressure differential between the supply line and the work port, and/or the pressure differential between the work port and the tank line.

Hydraulic systems and associated methods configured to reduce leakage past a spool valve when the system is in a neutral state. Leakage reduction is achieved by shifting the spool valve within the spool bore. The amount of shifting can be controlled by a pressure controller that sets one or pressures in the system and actively/dynamically adjusts the system to achieve a desired pressure or set of pressures by shifting the spool valve.

A valve device with a valve housing, which is penetrated by a fluid channel, which extends from an inlet connection to an outlet opening and in which a valve member is arranged, which is designed to regulate a cross-section of the fluid channel, with an electric drive device to influence a position of the valve member in the fluid channel including a stator that is fixed on the valve housing and an armature arranged so as to be movable relative to the stator wherein the armature and the valve member are arranged on a dimensionally-stable connection part, which is pivotably mounted on the valve housing with a flexure, wherein the flexure is designed for an electric connection of the armature to an electric connection device designed on the valve housing and wherein the connection part forms the valve member or carries the valve member.

Hydraulic systems and associated methods configured to reduce leakage past a spool valve when the system is in a neutral state. Leakage reduction is achieved by shifting the spool valve within the spool bore. The shifting direction can depend on whether the system has a relatively high load or a relatively low load in the neutral state. The amount of shifting can depend on the pressure differential between the supply line and the work port, and/or the pressure differential between the work port and the tank line.

Hydraulic systems and associated methods configured to reduce leakage past a spool valve when the system is in a neutral state. Leakage reduction is achieved by shifting the spool valve within the spool bore. The amount of shifting can be controlled by a pressure controller that sets one or pressures in the system and actively/dynamically adjusts the system to achieve a desired pressure or set of pressures by shifting the spool valve.

A smart load-sensing EHA, comprising a variable displacement hydraulic pump, a symmetrical hydraulic cylinder, a feedback module, a pressure-following valve and an execution mechanism. The symmetrical hydraulic cylinder includes a symmetrical plunger, a first cylinder and a second cylinder separated by the plunger. The variable displacement hydraulic pump includes an oil inlet and an oil outlet. An output of the feedback module is to output a greater one of pressures at the first input and the second input to the execution mechanism. The pressure-following valve is connected between the output of the feedback module and an input end of the execution mechanism to reduce an instantaneous flow input to the input end of the execution mechanism and adjust pressure at the input end thereof. The execution mechanism is to receive an output of the feedback module and generate signal for changing displacement of the variable displacement hydraulic pump.

A valve device with a valve housing, which is penetrated by a fluid channel, which extends from an inlet connection to an outlet opening and in which a valve member is arranged, which is designed to regulate a cross-section of the fluid channel, with an electric drive device to influence a position of the valve member in the fluid channel including a stator that is fixed on the valve housing and an armature arranged so as to be movable relative to the stator wherein the armature and the valve member are arranged on a dimensionally-stable connection part, which is pivotably mounted on the valve housing with a flexure, wherein the flexure is designed for an electric connection of the armature to an electric connection device designed on the valve housing and wherein the connection part forms the valve member or carries the valve member.

The control valve assembly includes a valve housing defining a bore and a valve assembly. The valve assembly includes a spool assembly disposed in the bore of the valve housing. The spool assembly includes a first spool and a second spool. The first spool has a first axial end and an oppositely disposed second axial end. The first spool is made of a first material. The first material is non-magnetic. The second spool has a first end and an oppositely disposed second end. The first end of the second spool is engaged to the second axial end of the first spool. The second spool is made of a second material. The second material is magnetic.

An intelligent load-sensing EHA, comprising a variable displacement hydraulic pump, a symmetrical hydraulic cylinder, a feedback module, a pressure-following valve and an execution mechanism. The symmetrical hydraulic cylinder includes a symmetrical plunger, a first cylinder and a second cylinder separated by the plunger. The variable displacement hydraulic pump includes an oil inlet and an oil outlet. An output of the feedback module is to output a greater one of pressures at the first input and the second input to the execution mechanism. The pressure-following valve is connected between the output of the feedback module and an input end of the execution mechanism to reduce an instantaneous flow input to the input end of the execution mechanism and adjust pressure at the input end thereof. The execution mechanism is to receive an output of the feedback module and generate signal for changing displacement of the variable displacement hydraulic pump.