Patent ID: 7779853
Filing Date: 2010-08-24
Classification: F15B,G05D,Y10T

Abstract:
1. A proportional pressure control valve for installation within a fluid system, the valve comprising when installed within the system: a cage which extends in an axial direction from a first end having an end face to a second end and in a radial direction, and includes a wall having an inner surface and an outer surface which define a thickness dimension therebetween, and the wall having formed therethrough a pump port opening in fluid communication with a pump port of the system for receiving fluid under pressure, a clutch port opening in fluid communication with a clutch port of the system for supplying such fluid to an actuator, and a tank port opening in fluid communication with a tank port of the system for returning such fluid to a tank; a spool received within the cage to be moveable axially relative to the cage for controlling fluid flow between the clutch port opening and the pump and tank port openings, the spool having a feedback pressure surface responsive to an applied feedback fluid pressure urging the spool to move axially relative to the cage in a first direction towards a first position allowing fluid flow between the clutch port and the tank port; a feedback pressure chamber defined within the cage for developing the feedback fluid pressure on the feedback pressure surface of the spool; a clutch port pressure feedback passage coupling the clutch port in fluid communication with the feedback pressure chamber for admitting a fluid flow from the clutch port into the feedback pressure chamber to develop the feedback fluid pressure on the feedback pressure surface of the spool, the clutch port pressure feedback passage being formed within the thickness dimension of the cage wall through an opening in the end face thereof to extend generally axially intermediate a first port in fluid communication with the feedback pressure chamber and a second port in fluid communication with the clutch port of the system, the first port being disposed between the second port and the cage end wall opening, and the first port opening generally radially into the feedback pressure chamber through the inner surface of the cage; and a plug inserted into the cage end wall opening, the cage end wall opening being closed by the plug.