Cooling oil cut-off valve for a clutch

摘要

A cooling oil cut-off valve is disclosed for use in a clutch having a rotatable drum fixed to a drive member and a rotatable hub fixed to a driven member. The hub is arranged within the drum so as to form a clutch chamber in which is positioned a clutch pack. The clutch pack is radially attached to both the drum and the hub and is axially engageable by a hydraulically actuated piston. Fluid flow to the piston is provided by means of a first fluid passage while the flow of cooling oil to the clutch chamber is provided by a second fluid passage. The clutch drum also contains a bore formed therein which intersects the first and second passages and which contains a cooling oil cut-off valve. The cooling oil cut-off valve is movable by fluid pressure to a first position when the clutch is engaged to permit cooling oil to flow to the clutch pack. The cut-off valve is also movable to a second position by centrifugal force which is generated by the rotational movement of the clutch drum to prevent the flow of cooling oil to the clutch pack when the clutch is disengaged. The cooling oil cut-off valve is designed to initially start moving toward the open position at a higher pressure than needed to keep it moving toward said open position.