Patent ID: 6637282
Filing Date: 2003-10-28
Classification: F16H,Y10T

Abstract:
A hydraulic actuation system for an automated transmission system comprising:a source of hydraulic fluid under pressure; a hydraulic fluid reservoir; a hydraulic clutch actuator for controlling engagement of a clutch, said hydraulic clutch actuator comprising a single acting ram with a single working chamber; a hydraulic gear engagement actuator for controlling engagement of a gear, said hydraulic gear engagement actuator comprising a double acting ram comprising first and second working chambers; a main control valve, the main control valve being switchable between a first position in which the clutch actuator and gear engagement actuator are connected to the source of fluid under pressure and a second position in which the clutch actuator and gear engagement actuator are connected to the reservoir; the working chamber of the clutch actuator being connected to the main control valve via a clutch control valve, the clutch control valve being switchable between a open position in which the working chamber of the clutch actuator is connected to the main control valve and a closed position in which the working chamber of the clutch actuator is isolated from the main control valve; the first and second working chambers of the gear engagement actuator being selectively connected to the main control valve or to the reservoir via first and second gear control valves respectively.