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Gehlhoff
Wade Gehlhoff, Shakopee, MN US
| Patent application number | Description | Published |
|---|---|---|
| 20090312852 | AUTO-TUNING ELECTRO-HYDRAULIC VALVE - A flow control valve includes a housing that includes a fluid inlet, a fluid outlet, a first work port and a second work port. The housing defines a spool bore and a pilot spool bore. A main stage spool is disposed in the spool bore. A pilot stage spool is disposed in the pilot spool bore. The pilot stage spool is in selective fluid communication with the main stage spool. A microprocessor includes a controller having a restricted structured controller and a compensation controller. Outputs of the restricted structured controller and the compensation controller are summed to form an electrical signal that is communicated to the pilot stage spool. | 12-17-2009 |
Wade L. Gehlhoff, Shakopee, MN US
| Patent application number | Description | Published |
|---|---|---|
| 20110083750 | METHOD FOR OPERATING A HYDRAULIC ACTUATION POWER SYSTEM EXPERIENCING PRESSURE SENSOR FAULTS - A method for operating a hydraulic actuation system during a pressure sensor malfunction is provided. The hydraulic actuation system includes a pump, a reservoir, a first work-port and a second work-port, a valve system with individual orifices, a pressure sensor system, and a controller for regulating the hydraulic actuation system based on fluid flow demand and on determined pressure differences. The method includes detecting a malfunction of a pressure sensor for the first work-port, closing second and third orifices, and regulating the pump to generate fluid flow corresponding to maximum pressure generated by the pump. The method also includes assigning a value for the difference between pump pressure and the pressure of the subject work-port that is equivalent to a value within an attainable range for difference between the two pressures. Furthermore, the method includes regulating a first orifice and a fourth orifice in response to the fluid flow demand. | 04-14-2011 |
| 20110126608 | OUT-OF-RANGE SENSOR RECALIBRATION - A method for resetting a calibration of a sensor operating out-of-range in a hydraulic actuation system is provided. The hydraulic actuation system includes a pump, a reservoir, a plurality of work-ports, a plurality of sensors, and a valve system, and a controller for regulating the hydraulic actuation system based on fluid flow demand and sensed pressures. The method includes detecting the sensor operating out-of-range, opening all work-ports to the reservoir, resetting all sensors to reservoir pressure, supplying all sensors with fluid at maximum pump pressure, and sensing the maximum pump pressure at each sensor. Additionally, the method includes determining an average pressure value across all sensors, assigning the determined average pressure value to the sensor that is operating out-of-range, and resetting the calibration of the sensor that is operating out-of-range based on the reservoir pressure and the average pressure values. | 06-02-2011 |
Wade Leo Gehlhoff, Shakopee, MN US
| Patent application number | Description | Published |
|---|---|---|
| 20090218161 | Control Valve Assembly for Electro-Hydraulic Steering System - A steering system includes a fluid pump and an electro-hydraulic steering circuit in selective fluid communication with the fluid pump. The electro-hydraulic steering circuit defines a first flow path having a first proportional valve and a first load-sense passage in selective communication with the first proportional valve. The first proportional valve includes a closed position. A hydrostatic steering circuit is in selective fluid communication with the fluid pump and defines a second flow path having a second proportional valve and a second load-sense passage in selective fluid communication with the second proportional valve. The second flow path is in a parallel flow configuration with the first flow path. An isolation valve is disposed in the first flow path in series with the first proportional valve. The isolation valve includes a closed position and is piloted to the closed position by fluid communicated through the second load-sense passage. | 09-03-2009 |
| 20090272598 | Isolation Valve for a Load-Reaction Steering System - A steering system includes a fluid actuator, a first steering circuit in selective fluid communication with the fluid actuator, and a second steering circuit in selective fluid communication with the fluid actuator and disposed in parallel to the first steering circuit. The second steering circuit includes a load-reaction feature and an isolation valve with the isolation valve being adapted to enable and disable the load-reaction feature. | 11-05-2009 |