Patent ID: 7047914

Claim:
A coolant pump for use with an internal combustion engine having a crankshaft and a camshaft driven by the crankshaft, said coolant pump comprising: a pump housing fixedly mountable to the engine and including an inlet opening to receive coolant and an outlet opening to discharge coolant; an impeller shaft operatively coupled to the camshaft so as to be rotatably driven thereby about an axis; and a pump impeller operatively mounted to the impeller shaft within the pump housing, the pump impeller rotatable to draw the coolant into the pump housing through the inlet opening and discharge the coolant at a higher pressure through the outlet opening, the pump impeller including first and second shrouds separated by a plurality of vanes, the first and second shrouds and plurality of vanes being configured and positioned such that a resultant thrust load acting on the pump impeller and hence the impeller shaft is substantially balanced, wherein the first and second shrouds are structured such that a thrust load applied to the first shroud is opposite in direction and substantially equal in magnitude to a thrust load applied to the second shroud.