Abstract: An exemplary hydraulic system includes a first digital valve fluidly connectable to a first hydraulic load and a pump. The first valve is operable to fluidly connect the first hydraulic load to the pump. A second digital valve is fluidly connectable to a second hydraulic load and the pump. The second valve is operable to fluidly connect the second hydraulic load to the pump. The system includes a first sensor for detecting a pump discharge pressure and a second sensor for detecting an inlet pressure of the first hydraulic load. A controller is configured to determine a time delay based on the pump discharge pressure and the first hydraulic load inlet pressure and to send a control signal instructing the second valve to commence opening at a time substantially equal to the time delay after commencing closing the first valve.

Abstract: Disclosed is an exemplary valve having a first valve member that may include at least one orifice, and which is moveable between a first position and a second position, and a second valve member that includes at least one orifice, and which is moveable relative to the first valve member between a first position, in which the at least one orifice of the second valve member is fluidly disconnected from the at least one orifice of the first valve member, and a second position, in which the at least one orifice of the second valve member is fluidly connected to the at least one orifice of the first valve member. The exemplary valve may also include first and second actuators for moving the first and second valve members between their respective first and second positions.

Abstract: In one embodiment, a hydraulic circuit has an input shaft, at least one positive displacement hydraulic pump, a plurality of positive displacement hydraulic motors, and at least one fluid line operatively connecting the at least one positive displacement hydraulic pump to the positive displacement hydraulic motors. In operation, the at least one positive displacement hydraulic pump is placed in an operative condition. At least one of the positive displacement hydraulic motors is also placed in an operative condition. A flow rate of fluid in the fluid line is measured, and the remaining positive displacement hydraulic motors are switched between an operative condition and a bypass condition according to the measured flow rate of the fluid.

Abstract: A valve is provided including a first valve member and a second valve member. The first valve member includes a first step and a first orifice adjacent the first step. The second valve member includes a second step and a second orifice adjacent the second step. The second valve member is movable relative to the first valve member between an open position, in which the first orifice is fluidly connected the second orifice, and a closed position, in which the first orifice is substantially fluidly disconnected from the second orifice. The first and second steps are fluidly connected to the second orifice and substantially fluidly disconnected from the first orifice when the second valve member is in the closed position, and the first and second steps are fluidly connected to the first and second orifices when the second valve member is in the open position.

Abstract: An exemplary hydraulic system includes a digital valve operable to fluidly connect a hydraulic load to a pressure supply, and an orifice disposed in a flow path between the hydraulic load and the digital valve. A digital controller is operably connected to the digital valve. The digital controller stores a target pressure drop across the orifice and is configured to determine an actual pressure drop across the orifice and formulate a control signal based on the target pressure drop and the actual pressure drop. The controller transmits the control signal to the digital valve for controlling the operation of the valve.

Abstract: An exemplary hydraulic system includes a digital valve operable to fluidly connect a hydraulic load to a pressure supply. A digital controller is operably connected to the digital valve. The digital controller stores a target value of a hydraulic system operating parameter and is configured to formulate a pulse width modulated control signal based on the target value. The digital controller transmits the control signal to the digital valve for controlling the operation of the valve.

Abstract: An exemplary hydraulic system includes a first digital valve fluidly connectable to a first hydraulic load and a pump. The first valve is operable to fluidly connect the first hydraulic load to the pump. A second digital valve is fluidly connectable to a second hydraulic load and the pump. The second valve is operable to fluidly connect the second hydraulic load to the pump. The system includes a first sensor for detecting a pump discharge pressure and a second sensor for detecting an inlet pressure of the first hydraulic load. A controller is configured to determine a time delay based on the pump discharge pressure and the first hydraulic load inlet pressure and to send a control signal instructing the second valve to commence opening at a time substantially equal to the time delay after commencing closing the first valve.

Abstract: A drive circuit may include a SUPPLY that outputs a first voltage potential, an energy storage device that outputs a second voltage potential, and a LOAD. Switches control the flow of current through the LOAD in a flow direction or in a direction opposite to the flow direction. The first or second voltage potentials can produce current.