Backfill pressure control valve for a rotating clutch

摘要

A rotating clutch has a feed passage that is maintained at a predetermined pressure by a backfill control valve during periods of clutch disengagement when the clutch apply chamber is not pressurized. The valve is slidably disposed in a stationary housing in fluid communication between a pressure source and the apply chamber of the clutch. When the pressure source is reduced below a predetermined level, the valve is positioned to prevent the pressure in the passage from decreasing below the predetermined level while exhausting the clutch apply chamber. When clutch actuation is desired, the pressure source increases to open the backfill valve. With the valve opened by pressure, the fluid pressure is supplied to the clutch apply chamber thereby applying the clutch. The valve is positioned in the housing to admit pressurized fluid from the source to the clutch apply chamber while disconnecting the apply chamber from exhaust when clutch apply is required.