Abstract: A partial stroke pump or motor includes a piston coupled to a rotating shaft to evacuate a fluid within a cylinder during an upstroke. A latching check valve includes an actuator piston that is displaceable within a center cavity to bypass a blocking member in a bypass state. The actuator piston is driven by a latch supply line. A spool of a rotary valve selectively couples one of the low and pilot pressure supplies to the latch supply line over different timing angle ranges of the rotating shaft. Coupling of the pilot pressure to the latch supply line causes the bypass state. When operating as a pump, the bypass state causes the pressure in the cylinder to fall below the high pressure during part of the upstroke. When operating as a motor, the bypass state allows the fluid to be evacuated from the cylinder during the upstroke.

Abstract: A device having a hybrid hydraulic-electric architecture includes a hydraulic pump/motor having first and second ports, and an electric motor. The device is configured to connect to two or more pressure rails, each pressure rail containing hydraulic fluid at a different pressure than the other pressure rails. A flow of hydraulic fluid from one of the pressure rails is driven through the hydraulic pump/motor, and a pressure difference exists between the first and second ports. The electric motor is configured to control a flow rate of the flow of hydraulic fluid and/or the pressure difference.

Abstract: A variable displacement pump-motor includes a pump-motor having a plurality of cylinders and pistons, and further including a main shaft rotatable relative to the system body. A hydro mechanical control system includes a plurality of main stage valves in communication with the plurality of cylinders. Each of the main stage valves is configured to open and close a cylinder of the plurality of cylinders to one or more of high or low pressure fluid sources. A pilot spool valve is in selective communication with each of the main stage valves. The pilot spool rotates with the main shaft. The pilot spool includes coding configured to operate each of the main stage valves to open and close the respective cylinders to the one or more high and low pressure fluid sources according to a translational position of the pilot spool and rotation of the pilot spool by the main shaft.

Abstract: A device having a hybrid hydraulic-electric architecture includes a hydraulic pump/motor having first and second ports, and an electric motor. The device is configured to connect to two or more pressure rails, each pressure rail containing hydraulic fluid at a different pressure than the other pressure rails. A flow of hydraulic fluid from one of the pressure rails is driven through the hydraulic pump/motor, and a pressure difference exists between the first and second ports. The electric motor is configured to control a flow rate of the flow of hydraulic fluid and/or the pressure difference.

Abstract: A variable displacement pump-motor includes a pump-motor having a plurality of cylinders and pistons, and further including a main shaft rotatable relative to the system body. A hydro mechanical control system includes a plurality of main stage valves in communication with the plurality of cylinders. Each of the main stage valves is configured to open and close a cylinder of the plurality of cylinders to one or more of high or low pressure fluid sources. A pilot spool valve is in selective communication with each of the main stage valves. The pilot spool rotates with the main shaft. The pilot spool includes coding configured to operate each of the main stage valves to open and close the respective cylinders to the one or more high and low pressure fluid sources according to a translational position of the pilot spool and rotation of the pilot spool by the main shaft.