Abstract: An apparatus for charging a hydraulic system from a fluid reservoir includes a pump having an inlet and an outlet, a first conduit fluidly connected to the pump inlet and fluidly connectable to the fluid reservoir, and a second conduit fluidly connected to the pump outlet and fluidly connectable to the system. The apparatus also includes an accumulator operatively connected to the second conduit, a third conduit interconnecting the first conduit and the second conduit, and an electrically actuated fill valve operatively disposed in the third conduit.

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: An apparatus for charging a hydraulic system from a fluid reservoir includes a pump having an inlet and an outlet, a first conduit fluidly connected to the pump inlet and fluidly connectable to the fluid reservoir, and a second conduit fluidly connected to the pump outlet and fluidly connectable to the system. The apparatus also includes an accumulator operatively connected to the second conduit, a third conduit interconnecting the first conduit and the second conduit, and an electrically actuated fill valve operatively disposed in the third conduit.

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: 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: 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: An apparatus for multiplexing a first hydraulic cylinder and a second hydraulic cylinder. Each cylinder has a head end port and a rod end port. The apparatus includes a tank, a pump connected to the tank, and a control valve having an inlet port connected to the pump, an outlet port connected to the tank, and first and second control ports. The apparatus also includes at least two two-position valves each having at least one port connected to a corresponding at least one of the first and second control ports and at least one other port connected to a corresponding one of the head end and rod end ports of the first and second hydraulic cylinders, the at least two two-position valves being operable to selectively divert hydraulic fluid from the respective first and second control ports of the control valve to one of the first and second hydraulic cylinders.

Abstract: Apparatus and methods for controlling the resistance to the movement of a steering shaft that is operable to move as a function of an operator input. A position sensor is coupled with the steering shaft and transmits a shaft position signal as a function of the position of the steering shaft. A processing device is coupled with the position sensor to receive the shaft position signal and transmits a resistance signal as a function of the shaft position signal. A resistance device is coupled with the processing device to receive the resistance signal and is coupled with the steering shaft, the resistance device resists the movement of the steering shaft as a function of the resistance signal.

Abstract: An improved method for manufacturing a solenoid. The method includes the step of providing a single piece ferromagnetic housing. The method also includes the step of forming a groove around the perimeter of the housing. The method further includes the step of filling the groove with a non-ferromagnetic material such that the non-ferromagnetic material forms an annular ferromagnetic piece that spans the entire groove in the housing. Finally, the method includes the step of removing an inside portion of the housing such that two separate ferromagnetic pieces are formed joined by the non-ferromagnetic piece.

Abstract: An actuator assembly that uses a fluctuating operational pressure generated by an injector oil pump to actuate an EGR valve is disclosed. The operational pressure is used to operate the actuator assembly without being adversely affected by the fluctuating nature of the operational pressure. The actuator assembly includes an actuator housing defining a chamber and an actuator oil inlet. The actuator oil inlet is in fluid communication with the pump outlet. The actuator assembly further includes a slider located within the chamber. The slider is positionable between a first slider position and a second slider position. The slider isolates the actuator oil inlet from the chamber when the slider is located in the first slider position. The actuator oil inlet is in fluid communication with the chamber when the slider is located in the second slider position. The actuator assembly still further includes a movement assembly for moving the slider between a first slider position and a second slider position.

Abstract: An armature assembly is provided for use in a solenoid actuator assembly having an energizable coil. The solenoid actuator assembly includes a housing and a bore disposed in the housing. The armature assembly has an outer surface and is positioned in the bore for axial sliding movement. The armature assembly has an outer surface which is of a diameter significantly less than a diameter of the bore and defines a fluid passage through the bore. Sleeve bearings are positioned at preselected spaced locations within the bore and extends about and in contact with a shaft of the armature assembly.

Abstract: Electromagnetic actuators having a coil and an armature are used in a number of applications in which it is useful to have an indication of the position of the armature with respect to the coil without the use of external sensors. Accordingly, an actuator control system is provided for determining the position of the armature with respect to the coil in response to the current magnitude and frequency of current flowing in the coil.

Abstract: An apparatus for determining the position of an armature of an electromagnetic actuator having a coil, the armature being movable to and between first and second positions in response to a current flowing in the coil. The apparatus includes circuitry for measuring the magnitude of current in the coil and producing a magnitude signal, measuring the rate of change of current in the coil and producing a rate of change signal, and measuring the derivative of flux linkage versus current in the coil in response to the rate of change signal and producing a flux linkage signal. The apparatus additionally includes circuitry for determining the position of the armature with respect to the coil in response to the magnitude and flux linkage signals.

Abstract: Electromagnetic actuators having a coil and an armature are used in a number of applications in which it is useful to have an indication of the position of the armature with respect to the coil without the use of external sensors. Accordingly, an actuator control system is provided for determining the position of the armature with respect to the coil in response to the magnitude and rate of change of current flowing in the coil.

Abstract: An assembly is provided for use in a solenoid having an energizable coil. The apparatus includes a ferromagnetic main body member adapted to be received in the coil. An armature chamber having a constant diameter is disposed in the main body member. A radially externally facing taper is formed in the outer surface of the main body member. The taper extends between the armature chamber and the outer surface of the main body member. A stationary pole piece and an end plug respectively define a first and second end of the armature chamber. An armature member is positioned in the armature chamber for axial sliding movement relative to and defining a working gap relative to the pole piece. The armature includes a fluid passage adapted to provide nonlaminar fluid flow. A nonferromagnetic sleeve is positioned on and fixedly connected to the main body member.

Abstract: Flow amplifying poppet valves are useful in hydraulic circuits requiring low leakage when the circuit is in a load holding condition. Pressure compensation of the known flow amplifying poppet valves has not been totally successful and thus, the output flow varies somewhat with changing pressure drops across the poppet valve. The subject pressure compensated flow amplifying poppet valve utilizes a pressure compensating valve and a compensating orifice disposed in a compensating flow path disposed in parallel with a valve device for controllably regulating fluid flow through a flow regulating passage. Fluid flow through the compensating flow path is restricted by the orifice to a flow rate substantially equal to the amount of fluid that can flow through a flow control slot in a valve element at a closed position of the valve element.