Abstract: A poppet valve arrangement is provided and has a poppet slideably disposed therein. The poppet has an odd number of integral guide legs formed thereon about the periphery of the poppet. The odd number of integral guide legs are evenly spaced from one another and are of a size sufficient to permit fluid to freely flow thereby when unseated. The integral guide legs also function to permit the poppet to freely slide, without binding, within a bore of the poppet valve arrangement. The poppet having integral guide legs is compact, versatile, cost effective to produce and has good strength.

Abstract: A unit injector assembly is provided that helps to ensure maximum injection flow while minimizing the harmful affects of pressure waves within the unit injector assembly. The unit injector assembly has a first fuel passageway extending from the plunger piston pumping chamber to the tip check stem injection chamber and valve seat. The unit injector assembly has a second fuel passageway extending from the tip check stem injection chamber to a fuel control valve assembly. A flow restricting fuel passageway connects one of the pumping chamber and the first fuel passageway with the second fuel passageway and acts to minimize cavitation at the valve seat and effectively eliminates pressure waves within the unit injector assembly.

Abstract: An apparatus and method for pumping oil in a machine. The apparatus and method includes a first gear drivably connected to the machine, a second gear connected to the machine such that a set of teeth located on the first gear engage a set of teeth located on the second gear, an oil inlet port located near the teeth of the first gear slightly before a point of engagement of the teeth of the first and second gears, and an oil outlet port located at the point of engagement of the teeth of the first and second gears.

Abstract: In a fluid system, a source of pressurized fluid operably communicates with first and second actuators. First and second control valves control fluidly communicates with the first and second actuators. A first pressure compensating valve fluidly communicates with the first control valve and first actuator. A first signal conduit fluidly communicates with fluid flow being directed by the first control valve to the first pressure compensating valve and first actuator. A second pressure compensating valve fluidly communicates with the second control valve and second actuator. A second signal conduit fluid communicates with fluid flow being directed by the second control valve to the second pressure compensating valve and second actuator. A control signal pressure generated from a greater of a first signal pressure carried by the first signal conduit and a second signal pressure carried by the second signal conduit fluidly communicates with the first and second pressure compensating valves.

Abstract: A fluid control system includes a pressure supply and a valve arrangement having an inlet and an outlet and being in fluid communication with the pressure supply. The valve arrangement includes a relief operator configured to provide fluid communication between the inlet and the outlet of the valve arrangement in response to a predetermined pressure condition at said inlet. The valve arrangement is configured to provide fluid communication between the inlet and the outlet of the valve arrangement in response to an outlet pressure being greater than an inlet pressure.

Abstract: A hydraulic regeneration system for a work machine is provided. The hydraulic regeneration system includes a first hydraulic actuator having a first chamber and a second chamber, a second hydraulic actuator having a third chamber and a fourth chamber, and a source of pressurized fluid. A first directional control valve is disposed between the source of pressurized fluid and the first chamber of the first hydraulic actuator and the third chamber of the second hydraulic actuator. A second directional control valve is disposed between the source of pressurized fluid and the second chamber of the first hydraulic actuator and the fourth chamber of the second hydraulic actuator. An accumulator may also be used to store pressurized fluid and selectively supply pressurized fluid to increase the efficiency of the work machine.

Abstract: A single stage, electrically controlled variable pressure relief valve assembly is provided that uses a valving element assembly slideably disposed within a housing having first and second inlet and outlet ports, the valving element assembly has a differential area defined thereon which acts in cooperation with an electrically controlled coil assembly to proportionally control the flow of fluid between the inlet port and an outlet ports of the housing. The valving element assembly has inlet and outlet ports that are oriented generally perpendicular to the flow of the fluid through the valving element assembly to effectively offset the effects of flow forces acting on the valving element.

Abstract: A fluid circuit is provided to independently control the flow of fluid into and out of each end of an actuator. This is accomplished by having two different independently controlled valves controlling the flow of fluid into and out of one end of the actuator and by having two other independently controlled valves controlling the flow of fluid into and out of the other end of the actuator. Regeneration of the fluid flow from one end of the actuator to the other end of the actuator is provided by blocking the exhaust flow of fluid to the reservoir by one of the independently controlled valves and redirecting the flow across the other of the independently controlled valves to join with the flow of the pump that is being directed to the other end of the actuator. This arrangement permits a portion or all of the fluid from one end of the actuator to be regenerated to the other end of the actuator.

Abstract: A fluid system having a common source of pressurized fluid is provided to selectively control the speed and/or pressure of a first hydraulic circuit while also providing flow/pressure priority to a second hydraulic circuit. The first hydraulic circuit includes a first electrically controlled proportional relief valve connected between the source of pressurized fluid and a first fluid actuator and a second electrically controlled proportional relief valve connected between the reservoir and a point downstream of the first electrically controlled proportional relief valve. The second hydraulic circuit is connected to the source of pressurized fluid in parallel with the first hydraulic circuit.

Abstract: The displacement of fluid translating devices are normally controlled by changing the angle of an eccentric or a cam plate to change the pumping stroke of the pistons within the device. In the subject arrangement, the displacement of the fluid translating device is controlled by controlling the flow being delivered into or away from each of the associated pressure chambers defined therein by the respective ones of a plurality of pistons. By not permitting the flow from every piston to be directed into useful work, the volume of fluid being directed into or away from the fluid translating device can be altered. Likewise, the direction of fluid flow within the fluid translating device can be selectively changed thus permitting the subject fluid translating device to be capable of pumping or motoring in both directions of flow relative to the first and second inlet/outlet ports thereof.

Abstract: A variable delivery pump is provided for use in a work system. The variable delivery pump includes a variable delivery control arrangement that uses reduced pressure from the variable delivery pump to control the delivery of fluid from the pump. The reduced pressure is directed to a first port of the variable delivery control arrangement and acts to bias the flow changing mechanism to a maximum position when the work system does not require fluid flow. When the work system needs pressurized fluid, the reduced pressure that is also being directed across a flow restrictor is progressively blocked thus causing a variable valve arrangement to controllably direct reduced pressurized fluid to a second fluid port of the flow changing mechanism in opposition to the pressurized fluid at the first fluid port. In the subject arrangement, small orifices requiring large flows is eliminated. Consequently, the subject control arrangement is not adversely subject to high viscosity oils.

Abstract: A variable displacement axial piston pump is typically used to receive fluid from a tank and supply pressurized fluid through a control valve to move an actuator. The present variable displacement axial piston pump has a swashplate arrangement that is capable of being angled in two different directions to control the pressure transitions between the low pressure inlet port passage and the higher pressure outlet port passage as cylinder bores in a barrel of a rotating group rotate through trapped volume regions situated between inlet and outlet port passages of the axial piston pump. Movement of the swashplate arrangement in two different directions provides smooth pressure transitions and increases the operating efficiency of the variable displacement axial piston pump.

Abstract: A power combining device is provide for use in a work system to combine mechanical power and hydraulic power. The power combining device includes a first rotatable input/output member connected to a power source, a second rotatable input/output member connected to a working member. A valving plate, a drive sleeve and a camplate are drivingly connected to the first rotatable input/output member. A rotating barrel having a plurality of piston disposed therein to define pressure chambers is drivingly connected to the second rotatable input/output member and operative in cooperation with the valving plate to control pressurized fluid within the pressurized chambers. The subject power combining device is compact and cost effective to produce.

Abstract: It is desirable to deliver only the fluid that is used to do useful work and not waste energy. In the subject arrangement, selected ones of a plurality of pistons are held at their top dead center positions when delivery therefrom is not needed. This is accomplished by having a valving arrangement disposed between the associated pressure chambers and first and second inlet/outlet ports. The valving arrangement is movable from a neutral, flow blocking position to an operative flow passing position. At the flow blocking position, fluid flow into and out of the associated pressure chamber is blocked, thus the associated piston is maintained at the top dead center position. By holding selected ones of the pistons at the top dead center position, the effective volume of fluid being used is reduced and energy is saved due to the fact that the selected pistons are not moving any fluid.

Abstract: A fluid translating device is provided that includes a first member having fluid inlet/outlet ports and a second member having a plurality of pistons disposed therein secured to a stationary central shaft. A camplate and port plate is disposed in the fluid translating device about the stationary central shaft and located between the first and second members. The camplate is in communication with the fluid inlet/outlet ports and the plurality of pistons is in mating contact with the port plate. An outer input/output member is secured about the camplate and is rotatably disposed about the first and second members to form a compact arrangement.

Abstract: A pilot control system for maintaining a constant operating hydraulic fluid pressure in a hydraulic system throughout a range of hydraulic fluid flow and temperature conditions. The pilot control system has a pilot pump and a pilot relief valve in fluid communication with the pilot pump. A first pressure reducing valve is in fluid communication with the pilot pump and the pilot relief valve so as to reduce the pressure to components downstream of the pressure reducing valve.

Abstract: The present invention provides a method and apparatus for determining the oil grade of an actuating fluid in a fuel system. The method includes the steps of determining an actuating fluid temperature, a pump speed, and a peak pressure or a timing event of the actuating fluid, and responsively determining the oil grade of the actuating fluid.

Abstract: A snubbing arrangement functions to control the rate of deceleration of a piston and rod assembly within a fluid cylinder as the piston and rod assembly nears the bottom of the piston cavity. A flow blocking mechanism is attached to the piston and rod assembly and acts to block flow from the piston cavity through a first head end port. A pressure differential valve mechanism is disposed between a second head end port and the rod end port and operative to control the pressure in the head end cavity relative to the pressure in the rod end cavity.

Abstract: A control arrangement is provided to control the output of a hydrostatic transmission in response to a selectable input from an operator. This is accomplished by having a adjustable relief valve connected to the pilot control arrangement that controls the displacement of the variable displacement pump of the hydrostatic transmission. The adjustable relief valve vents a portion of the pilot control pressure being directed to the variable displacement pump in response to the pressure between the variable displacement pump and the fluid motor of the hydrostatic transmission and the setting of the adjustable relief valve by the operator.

Abstract: A system for controlling an independent metering valve having a pair of independently controlled electrohydraulic displacement controlled spool valves for controlling pump-to-cylinder communication between an inlet port and a pair of control ports and another pair of independently controlled electrohydraulic displacement controlled spool valves for controlling cylinder-to-tank fluid flow between the control ports and an outlet port. The spool valves of the independent metering valve are calibrated to provide the required fluid flow.