EXHAUST GAS RECIRCULATION VALVE WITH BALANCE OF GAS FLOW FORCE

摘要

A relatively simple pressure balanced high flow exhaust gas recirculation (EGR) valve (10) includes an actuator and a separately formed valve assembly (12) retained to the actuator by a deformed lip (38). The valve body (26) has dual seats (62, 64) controlled by axially spaced heads (78, 76) which are pressure balanced when closed and allow high gas flow when open. The valve body (26) and the associated valve shaft (74), or portions thereof, are formed of materials having similar coefficients of thermal expansion so that the shaft and body experience similar thermal growth and good seating of the spaced valves is maintained regardless of gas temperature variations. Thickened portions at the valve seats comprise annular ends (52, 56) of a control portion (32) which resist distortion of the seats. The valve body (26) is configured for installation in a cylindrical bore or recess of an associated manifold or other gas passage defining member.