Abstract: A valve assembly for a pump includes an electrical actuator having a stator and an armature. The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel formed radially between the outer stator portion and the inner stator portion. A first radial channel extending through the annular outer stator portion between an outer surface of the outer stator portion and the annular channel, and at least one second opening in the annular outer stator portion results in magnetic symmetry of the stator. Upon activating the electrical actuator, the attraction of the armature towards the stator is uniform thus displacing fluid between the stator and armature in a uniform manner and to avoid high velocity, potentially damaging fluid flow.

Abstract: A valve assembly for a pump includes an electrical actuator having a stator and an armature. The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel formed radially between the outer stator portion and the inner stator portion. A first radial channel extending through the annular outer stator portion between an outer surface of the outer stator portion and the annular channel, and at least one second opening in the annular outer stator portion results in magnetic symmetry of the stator . Upon activating the electrical actuator, the attraction of the armature towards the stator is uniform thus displacing fluid between the stator and armature in a uniform manner and to avoid high velocity, potentially damaging fluid flow.

Abstract: A hydraulic system is disclosed for use with a machine. The hydraulic system may have a closed-loop, meterless hydraulic circuit with a first pump fluidly connected to a first actuator. The hydraulic system may also have a closed-loop, metered hydraulic circuit with a second pump fluidly connected to a second actuator. The hydraulic system may further have a combiner valve configured to selectively direct fluid from the closed-loop metered hydraulic circuit to the closed-loop meterless hydraulic circuit.

Abstract: A bearing arrangement for a wobble plate piston pump includes first, second, third, and fourth bearing assemblies. The first and second bearing assemblies support the drive shaft portion for rotation within the housing about the central longitudinal axis, while the third and fourth bearing assemblies support the load plate for rotation relative to the offset shaft portion of the shaft. The second bearing assembly is distally disposed from the first, the third disposed distally to second, and the fourth disposed distally to third. The fourth bearing assembly is the most distally disposed bearing assembly along the shaft.

Abstract: A cryogenic pump comprising a shaft disposed in a bearing. The shaft rotates with respect to the bearing housing, and the shaft includes an end with an angled face. The pump includes a drive at one end of the bearing housing. A tappet passage is formed through the drive housing. A pushrod housing connects to the drive housing. The pump includes a piston and a tappet sliding within the tappet passage. The tappet has a base end disposed within the tappet passage and a rod end extending below the tappet end of the drive housing. A fluid cavity is in the tappet passage between the piston and the tappet. The pump includes a pushrod connected to the tappet. The angled face of the shaft rotates and drives the piston toward the drive housing, pushing fluid within the fluid cavity against the tappet, driving the pushrod away from the drive housing.

Abstract: A hydraulic system is disclosed for use with a machine. The hydraulic system may have a closed-loop, meterless hydraulic circuit with a first pump fluidly connected to a first actuator. The hydraulic system may also have a closed-loop, metered hydraulic circuit with a second pump fluidly connected to a second actuator. The hydraulic system may further have a combiner valve configured to selectively direct fluid from the closed-loop metered hydraulic circuit to the closed-loop meterless hydraulic circuit.

Abstract: A cryogenic pump comprising a shaft disposed in a bearing. The shaft rotates with respect to the bearing housing, and the shaft includes an end with an angled face. The pump includes a drive at one end of the bearing housing. A tappet passage is formed through the drive housing. A pushrod housing connects to the drive housing. The pump includes a piston and a tappet sliding within the tappet passage. The tappet has a base end disposed within the tappet passage and a rod end extending below the tappet end of the drive housing. A fluid cavity is in the tappet passage between the piston and the tappet. The pump includes a pushrod connected to the tappet. The angled face of the shaft rotates and drives the piston toward the drive housing, pushing fluid within the fluid cavity against the tappet, driving the pushrod away from the drive housing.

Abstract: A bearing arrangement for a wobble plate piston pump includes first, second, third, and fourth bearing assemblies. The first and second bearing assemblies support the drive shaft portion for rotation within the housing about the central longitudinal axis, while the third and fourth bearing assemblies support the load plate for rotation relative to the offset shaft portion of the shaft. The second bearing assembly is distally disposed from the first, the third disposed distally to second, and the fourth disposed distally to third. The fourth bearing assembly is the most distally disposed bearing assembly along the shaft.

Abstract: A shaft arrangement for an axial piston pump assembly to couple to a rotatable member such as a gear therewith. A shaft extends at least partially through a housing chamber of the pump about a longitudinal axis. Reciprocating pistons are disposed within the chamber radially about the shaft. A cam unit is fitted over the shaft and provides an angled camming surface to engage the pistons. Bearing assemblies are fitted over the cam unit. An adapter can be fitted over the proximal end of the cam unit. The adapter has a distal surface which may abut the bearing assembly and be axially spaced from the cam unit, and an outer radial surface to engage the rotatable member. A clamping device provides a desired clamp load path between the rotatable member, the adapter, the cam unit, the bearing assemblies and the shaft.

Abstract: A hydraulic circuit is provided. The hydraulic circuit includes a primary pump, a displacement actuator, a charge pump, a direction control valve, and a pressure control valve. The displacement actuator is associated with the primary pump. The charge pump is configured to generate a flow of a pilot fluid. The direction control valve is configured to control the flow of the pilot fluid to the displacement actuator to affect a movement direction of the displacement actuator. The pressure control valve is configured to control a pressure of the pilot fluid to affect a movement amount of the displacement actuator. Further, the hydraulic circuit includes a controller. The controller is configured to control the direction and the pressure control valves to adjust a displacement of the primary pump based at least on one of a sensed engine parameter or a mode of operation of the primary pump.

Abstract: A hydraulic fan circuit is disclosed. The hydraulic fan circuit may have a primary pump, a motor, a fan connected to and driven by the motor, and a flywheel connected to and driven by one of the motor and the fan. The hydraulic fan circuit may also have a supply passage extending from the primary pump to the motor, a return passage extending from the motor to the primary pump, and a diverter valve configured to selectively connect the supply passage to a low-pressure sump.

Abstract: A method for estimating a fluid charge of a hydraulic accumulator includes determining a first accumulator pressure at a first time with a pressure sensor, the first time during accumulator charging; determining a second accumulator pressure at a second time with the pressure sensor, the second time during accumulator charging; determining a first fan speed at the first time; determining a second fan speed at the second time; and estimating the fluid charge of the hydraulic accumulator as a function of the first accumulator pressure, the second accumulator pressure, the first fan speed, and the second fan speed.

Abstract: A hydraulic circuit is disclosed. The hydraulic circuit may have a pump, a motor, a tank, and an accumulator. The hydraulic circuit may also have a valve movable between a first position at which an output of the pump is fluidly connected to the tank and the accumulator is fluidly connected to the motor, and a second position at which the output of the pump is fluidly connected to the motor.

Abstract: A hydraulic fan circuit includes a primary pump, a motor fluidly connected to the primary pump, and a fan operably connected to and driven by the motor. The circuit also includes a supply passage extending from the primary pump to the motor, a return passage extending from the motor to the primary pump, and a pressure limiting valve configured to selectively reduce pressure of a flow of pilot fluid directed to the primary pump. The circuit further includes an override valve configured to selectively connect the supply passage to the pressure limiting valve.

Abstract: A hydraulic fluid system for a mobile machine includes a closed loop hydraulic fan circuit. The hydraulic fan circuit includes a primary pump, a motor fluidly connected to the primary pump, and a fan driven by the motor. The hydraulic fan circuit also includes a supply passage extending from the primary pump to the motor, a return passage extending from the motor to the primary pump, and a first accumulator selectively fluidly connected to at least one of the supply and return passages via a charge valve. The hydraulic fluid system also includes at least one open loop hydraulic circuit fluidly connected to the first accumulator.

Abstract: A pump is disclosed. The pump may have a housing, a body rotatably disposed within the housing and at least partially defining a plurality of barrels, a plurality of plungers associated with the plurality of barrels, and a swashplate tiltable by a swivel torque to vary a displacement of the plurality of plungers relative to the plurality of barrels. The pump may also have a port plate with an inlet port, a discharge port, and a protrusion. The port plate may be configured to engage an end of the rotatable body. The pump may further have at least one piston disposed within the housing and configured to selectively engage the protrusion of the port plate to rotate the port plate and adjust the swivel torque.

Abstract: A pump is disclosed. The pump may have a housing, and a body disposed within the housing and at least partially defining a plurality of barrels. The pump may also have a plurality of plungers associated with the plurality of barrels, and a plunger engagement surface. The plunger engagement surface may have geometry configured to reciprocate the plurality of plungers within the plurality of barrels as the plurality of plungers rotate relative to the plunger engagement surface, and a plurality of undulations configured to reduce a flow pulsation of the pump.

Abstract: A hydraulic circuit is provided. The hydraulic circuit includes a primary pump, a displacement actuator, a charge pump, a direction control valve, and a pressure control valve. The displacement actuator is associated with the primary pump. The charge pump is configured to generate a flow of a pilot fluid. The direction control valve is configured to control the flow of the pilot fluid to the displacement actuator to affect a movement direction of the displacement actuator. The pressure control valve is configured to control a pressure of the pilot fluid to affect a movement amount of the displacement actuator. Further, the hydraulic circuit includes a controller. The controller is configured to control the direction and the pressure control valves to adjust a displacement of the primary pump based at least on one of a sensed engine parameter or a mode of operation of the primary pump.

Abstract: A method for charging an accumulator is disclosed. The method includes pumping pressurized fluid from an output port of a hydraulic pump to the accumulator to charge the accumulator, and flowing makeup fluid from a hydraulic actuator system to an input port of the hydraulic pump.

Abstract: A shaft arrangement for an axial piston pump assembly to couple to a rotatable member such as a gear therewith. A shaft extends at least partially through a housing chamber of the pump about a longitudinal axis. Reciprocating pistons are disposed within the chamber radially about the shaft. A cam unit is fitted over the shaft and provides an angled camming surface to engage the pistons. Bearing assemblies are fitted over the cam unit. An adapter can be fitted over the proximal end of the cam unit. The adapter has a distal surface which may abut the bearing assembly and be axially spaced from the cam unit, and an outer radial surface to engage the rotatable member. A clamping device provides a desired clamp load path between the rotatable member, the adapter, the cam unit, the bearing assemblies and the shaft.