Patent ID: 7053498
Filing Date: 2006-05-30
Classification: F15B,F16H

Abstract:
1. A hydraulic control system for driving an auxiliary power source, located aboard a motor vehicle having a primary power source, at constant speed despite fluctuations in rotational speed of the primary power source, the system comprising: a hydraulic pump drivably connectable to the primary power source, the hydraulic pump having an inlet for receiving fluid for pumping and an outlet for discharging pumped fluid under pressure; a hydraulic motor drivably connectable to the auxiliary power source, the hydraulic motor having an inlet for receiving fluid under pressure and an outlet for discharging spent fluid; a fluid circuit including a supply conduit for conducting fluid discharged by the pump to the motor, a return conduit for returning fluid discharged by the motor to the pump, and a bypass conduit for conducting fluid discharged by the pump directly to the return conduit, bypassing the motor, and returning fluid to the pump; a proportional control valve assembly disposed serially with respect to the supply conduit and interposed between the outlet of the pump and the inlet of the motor, the control valve assembly having a housing including a valve chamber, a valve disposed within the valve chamber for apportioning the flow of fluid between the supply conduit and the bypass conduit, a solenoid drivably connectable to the valve for selectively moving the valve incrementally within the valve chamber from an open position to a closed position, a first fluid passage in fluid communication with the valve chamber and the supply conduit going to the motor, a second fluid passage in fluid communication with the valve chamber and the bypass conduit, wherein the valve selectively closes and opens the first fluid passage and the second fluid passage proportionally dividing the flow of fluid therebetween; and a control circuit in electrical communication with the valve assembly for controlling the valve assembly and hence the fluid flow within the first fluid passage to the motor supply conduit and the second fluid passage to the bypass conduit.