EGR assembly mounted on exhaust system of a heavy duty diesel engine

摘要

An exhaust gas recirculation (EGR) assembly (23) for an internal combustion engine, including an EGR valve (54) having a valve stem (55) reciprocating within a housing (61), between open (FIG. 3) and closed positions. Preferably, the EGR assembly is mounted on the exhaust manifold (15), and the EGR valve can communicate exhaust gas back to the intake manifold (13) in a known manner. The EGR assembly includes an electric motor (41), and a gear train (65) to move the EGR valve (54) in response to changes in an electrical input signal. A plurality of power electronic components (97) are disposed within a controls housing (91), which defines a slot (99) in face-to-face relation to a cooling chamber (81) defined by the housing (61) surrounding the valve stem (55). The cooling chamber (81) and the slot (99) cooperate to define a coolant passage, and the valve stem (55) and the power components (97) are in close proximity to the coolant passage, thus permitting the use of less expensive electrical components, rated for relatively lower temperatures.