Abstract: A pump includes a housing defining an internal chamber having an axial inlet passage, a generally radial passage with an outlet to a volute. A rotatable impeller, disposed within the chamber, has a conical rear shroud sloping away from the axial inlet to define a rear recess. A shaft seal is disposed within the recess to minimize the axial length of the pump. A front surface of the shroud carries vanes operable to impel fluid from the axial inlet passage to the volute. Portions of the vanes extend forward into the axial inlet passage to induce coolant pre-rotation in the inlet passage and to improve pump efficiency. Pump efficiency may be further increased by a conical wall defining the axial inlet passage, a sloped wall defining the radial passage and a large radius between the axial inlet and the sloped wall to smooth fluid flow between the axial inlet passage and the volute.

Abstract: A pump includes a housing defining an internal chamber having an axial inlet passage, a generally radial passage with an outlet to a volute. A rotatable impeller, disposed within the chamber, has a conical rear shroud sloping away from the axial inlet to define a rear recess. A shaft seal is disposed within the recess to minimize the axial length of the pump. A front surface of the shroud carries vanes operable to impel fluid from the axial inlet passage to the volute. Portions of the vanes extend forward into the axial inlet passage to induce coolant pre-rotation in the inlet passage and to improve pump efficiency. Pump efficiency may be further increased by a conical wall defining the axial inlet passage, a sloped wall defining the radial passage and a large radius between the axial inlet and the sloped wall to smooth fluid flow between the axial inlet passage and the volute.