Two-Way High Pressure Loop, Exhaust Gas Recirculation Valve: 5,740,785

A single exhaust gas recirculation valve selectively provides flow distribution of exhaust gas from an engine manifold to a turbocharger or exhaust gas recirculation system, and simultaneously provides back pressure for driving the recirculated exhaust gas to the intake manifold of the engine when the valve is positioned to recirculate all or part of the exhaust gas. A "wing-type" throttle blade is rotatably positioned within the valve and is selectively positionable between a first blocking position at which the exhaust gas recirculation port is blocked, and a second position at which the flow of exhaust gas to the turbine section of a turbocharger is blocked, as well as intermediate positions between the two blocked positions. The bearings supporting a shaft, to which the throttle blade is attached, are water cooled, as well as a mounting flange and shell surrounding an electric stepper motor coupled to the shaft. The present invention solves the problem of providing a compact EGR flow and back pressure valve in close proximity to the hot environment surrounding the exhaust manifold of an engine and a turbocharger.