Patent ID: 6725813
Filing Date: 2004-04-27
Classification: F01P,F04D

Abstract:
A viscous type water pump used to control the flow rate of engine coolant within a coolant chamber coupled to an internal combustion engine, the water pump comprising:an input member including a clutch plate coupled to a water pump shaft; a belt operatively coupled to the internal combustion engine and said input member, said belt capable of causing the rotation of said input member around a central axis, said central axis defined along the length of said water pump shaft; an output member rotatably coupled to said water pump shaft, said output member including a body and an impeller cover having a plurality of impeller blades contained within the coolant chamber, wherein said clutch plate is located within said body and said impeller cover; a working chamber defined between said output member and said clutch plate; an operating chamber fluidically coupled to said working chamber and defined between said output member and said clutch plate; a reservoir plate rotatably coupled to said water pump shaft between said clutch plate and said impeller cover, said reservoir plate having a fill hole and a scavenge hole, said reservoir plate and said impeller cover defining a fluid reservoir; a viscous fluid contained within said fluid reservoir; and a bimetallic control element positioned in said fluid reservoir and coupled to said reservoir plate, said bimetallic control element capable of sensing engine coolant temperature through said impeller cover, and capable of movement between a first position and a second position as a function of said sensed engine coolant temperature to control the flow rate of said viscous fluid from said working chamber to said fluid reservoir.