Abstract: A linear actuator configured to axially move a plunger. The linear actuator includes a flux sleeve surrounded by a bobbin housing a wire coil. The flux sleeve defines an armature cavity extending along a movement axis, where a magnetic field is created within the flux sleeve when a current is applied to the wire coil. An armature is receivable within the armature cavity, where the magnetic field created within the flux sleeve acts upon the armature such that the armature moves along the movement axis based on the magnetic field, and where moving the armature moves the plunger. A liner is positioned within the armature cavity between the armature and the flux sleeve. The liner includes at least one of a polyamide and a polyimide.

Abstract: A method is disclosed for determining off-temperature behavior of a solenoid fluid control valve. The method comprises performing a current sweep at a first temperature. The method further comprises choosing a first and second characterization control pressure for characterizing the solenoid fluid control valve. A first current may be determined that corresponds to the first characterization control pressure based on the current sweep, and a first metric may be assigned to the solenoid fluid control valve based on the first current. A second current corresponding to the second characterization control pressure may be determined based on the current sweep, and a second metric may be assigned to the solenoid fluid control valve based on the second current. Information regarding the behavior of the solenoid fluid control valve at a second temperature may be determined based on the first and second metrics.

Abstract: A method for characterizing a fluid control solenoid with current compensation is described. A current command is sent to the fluid control solenoid. The current command indicates a desired current value related to a desired fluid output pressure to be applied to the solenoid. An actual fluid output pressure is measured at a valve associated with the fluid control solenoid for the desired current value applied to the solenoid. An actual current received value at the fluid control solenoid is also measured. Post processing is then applied. A compensated current value related to the actual fluid output pressure is determined based on a difference between the current command and the actual current received value. Methods for dynamic current compensation are also described.

Abstract: Electrohydraulic solenoids with improved filtering of venting fluid are provided herein. In some embodiments, an electrohydraulic solenoid comprises a hollow cylindrical bobbin having a flange at a first end with a core having a cavity open at one end disposed in the hollow of the bobbin. An armature is disposed within the cavity and supported for axial movement within the cavity. A portion of a pole piece is disposed in the hollow of the bobbin at the first end with an axial face of the portion abutting the open end of the cavity and a shoulder axially spaced from the flange forming a gap. A vent path is formed between the cavity and an outer environment, the vent path comprising at least a portion of the gap, with a magnet disposed in a portion of the vent path.

Abstract: An electromagnetic solenoid is disclosed. The solenoid includes a coil, a bobbin, a flux sleeve, an armature, and a pole piece, arranged in such a way that the solenoid is robust against misalignment of the pole piece with the flux sleeve. The configuration facilitates the integration of either the pole piece or the flux sleeve into a hydraulic circuit.

Abstract: A method is disclosed for determining off-temperature accuracy information of a solenoid fluid control valve. The method comprises performing a current sweep at a first temperature, and for at least one command pressure, determining an error in a control pressure based on the current sweep. The error may be determined at the first temperature. A metric may then calculated based on the current sweep, and a pressure error offset may be determined for a second temperature based on the metric. The pressure error offset may describe a difference between the error in control pressure at the first temperature and an expected error in control pressure at the second temperature.

Abstract: An electromagnetic solenoid having a coil wound around a bobbin between first and second flanges for generating a magnetic force is disclosed. An armature having an armature flange at a first end is within an interior portion of the tubular center section of the bobbin and is supported for axial displacement between a first position and a second position. A permanent ring magnet is placed at the first end flange with an inner radial face spaced apart from an outer radial face of the armature flange by a radial gap, with the ring magnet supported by a retainer adjacent to the first end flange and fixed against axial displacement with respect to the bobbin. The solenoid comprises an outer case having a closed bottom at a first end and an open top at a second end and a flux washer disposed in the open top adjacent to a second end of the armature.

Abstract: A method is disclosed for determining off-temperature behavior of a solenoid fluid control valve. The method comprises performing a current sweep at a first temperature. The method further comprises choosing a first and second characterization control pressure for characterizing the solenoid fluid control valve. A first current may be determined that corresponds to the first characterization control pressure based on the current sweep, and a first metric may be assigned to the solenoid fluid control valve based on the first current. A second current corresponding to the second characterization control pressure may be determined based on the current sweep, and a second metric may be assigned to the solenoid fluid control valve based on the second current. Information regarding the behavior of the solenoid fluid control valve at a second temperature may be determined based on the first and second metrics.

Abstract: A solenoid fluid control valve is disclosed for controlling a variable displacement pump. The solenoid fluid control valve comprises a fixed solenoid component, a movable armature component, a fixed nozzle body, a movable spool within the fixed nozzle body, and a valve member. The valve member regulates fluid pressure in a first and second feedback chamber. Fluid in the second feedback chamber establishes a second feedback pressure that acts on the movable spool with a motive feedback force in a first axial direction. The movable spool moves in the first axial direction in response to the motive feedback force.

Abstract: Electrohydraulic solenoids with improved filtering of venting fluid are provided herein. In some embodiments, an electrohydraulic solenoid comprises a hollow cylindrical bobbin having a flange at a first end with a core having a cavity open at one end disposed in the hollow of the bobbin. An armature is disposed within the cavity and supported for axial movement within the cavity. A portion of a pole piece is disposed in the hollow of the bobbin at the first end with an axial face of the portion abutting the open end of the cavity and a shoulder axially spaced from the flange forming a gap. A vent path is formed between the cavity and an outer environment, the vent path comprising at least a portion of the gap, with a magnet disposed in a portion of the vent path.

Abstract: A method is disclosed for determining off-temperature behavior of a solenoid fluid control valve. The method comprises performing a current sweep at a first temperature. The method further comprises choosing a first and second characterization control pressure for characterizing the solenoid fluid control valve. A first current may be determined that corresponds to the first characterization control pressure based on the current sweep, and a first metric may be assigned to the solenoid fluid control valve based on the first current. A second current corresponding to the second characterization control pressure may be determined based on the current sweep, and a second metric may be assigned to the solenoid fluid control valve based on the second current. Information regarding the behavior of the solenoid fluid control valve at a second temperature may be determined based on the first and second metrics.

Abstract: A method for characterizing a fluid control solenoid with current compensation is described. A current command is sent to the fluid control solenoid. The current command indicates a desired current value related to a desired fluid output pressure to be applied to the solenoid. An actual fluid output pressure is measured at a valve associated with the fluid control solenoid for the desired current value applied to the solenoid. An actual current received value at the fluid control solenoid is also measured. Post processing is then applied. A compensated current value related to the actual fluid output pressure is determined based on a difference between the current command and the actual current received value. Methods for dynamic current compensation are also described.

Abstract: An electromagnetic solenoid is disclosed. The solenoid includes a coil, a bobbin, a flux sleeve, an armature, and a pole piece, arranged in such a way that the solenoid is robust against misalignment of the pole piece with the flux sleeve. The configuration facilitates the integration of either the pole piece or the flux sleeve into a hydraulic circuit.

Abstract: A method is disclosed for determining off-temperature accuracy information of a solenoid fluid control valve. The method comprises performing a current sweep at a first temperature, and for at least one command pressure, determining an error in a control pressure based on the current sweep. The error may be determined at the first temperature. A metric may then calculated based on the current sweep, and a pressure error offset may be determined for a second temperature based on the metric. The pressure error offset may describe a difference between the error in control pressure at the first temperature and an expected error in control pressure at the second temperature.

Abstract: A method is disclosed for determining off-temperature behavior of a solenoid fluid control valve. The method comprises performing a current sweep at a first temperature. The method further comprises choosing a first and second characterization control pressure for characterizing the solenoid fluid control valve. A first current may be determined that corresponds to the first characterization control pressure based on the current sweep, and a first metric may be assigned to the solenoid fluid control valve based on the first current. A second current corresponding to the second characterization control pressure may be determined based on the current sweep, and a second metric may be assigned to the solenoid fluid control valve based on the second current. Information regarding the behavior of the solenoid fluid control valve at a second temperature may be determined based on the first and second metrics.

Abstract: A solenoid fluid control valve is disclosed for controlling a variable displacement pump. The solenoid fluid control valve comprises a fixed solenoid component, a movable armature component, a fixed nozzle body, a movable spool within the fixed nozzle body, and a valve member. The valve member regulates fluid pressure in a first and second feedback chamber. Fluid in the second feedback chamber establishes a second feedback pressure that acts on the movable spool with a motive feedback force in a first axial direction. The movable spool moves in the first axial direction in response to the motive feedback force.

Abstract: A direct acting solenoid actuator includes an armature and associated push pin that are suspended from certain fixed solenoid components, such as a pole piece and/or flux sleeve, by a fully floating cage of rolling elements. The fixed solenoid component may comprise a pole piece and/or a flux sleeve. The pole piece may include stops to limit movement of the cage of rolling elements in the axial direction.

Abstract: A solenoid actuator comprising an armature member that engages a spool including a spool cap on an end of the spool that is axially movable relative to the spool. A bore in the spool allows fluid to flow from a control port to the spool cap, such that pressure is established in the spool cap. The pressure established in the spool cap acts on the spool with a force directly proportional to the control pressure and the fluid-contacting area inside the spool cap.

Abstract: An electromagnetic solenoid having a coil wound around a bobbin between first and second flanges for generating a magnetic force is disclosed. An armature having an armature flange at a first end is within an interior portion of the tubular center section of the bobbin and is supported for axial displacement between a first position and a second position. A permanent ring magnet is placed at the first end flange with an inner radial face spaced apart from an outer radial face of the armature flange by a radial gap, with the ring magnet supported by a retainer adjacent to the first end flange and fixed against axial displacement with respect to the bobbin. The solenoid comprises an outer case having a closed bottom at a first end and an open top at a second end and a flux washer disposed in the open top adjacent to a second end of the armature.

Abstract: Solenoid operated fluid control valve for controlling the pressure of a fluid in a fluid control system comprises a solenoid housing having therein a solenoid coil, an armature movable in response to electrical current applied to the solenoid coil, a valve member for controlling fluid flow to a fluid passage, an actuator pin disposed between the armature and the valve member for moving the valve member in response to armature movement, and one or more features including an armature damping member, tubular actuator pin support body, flow diverter, coil bobbin support sleeve, and/or internal particle gettering magnet to improve valve operation.