Abstract: A high capacity centrifugal pump for the transfer of liquids is presented. The pump comprises four major components held in rigid assembly by means of screws and pins: a drive unit which includes a drive shaft, a keyway and key, an end play control collar and an impeller mounting fixture; a one piece pump housing comprising mounting legs and a large internal diameter outlet port, a circular pump chamber cavity and a shaft hole containing a lip seal and a pair of flanged sleeve bearings; a one piece impeller of a width slightly less than its diameter; an end plate encompassing a large diameter inlet port. The drive shaft and attached impeller are mounted off center in the cylindrical pump chamber to permit liquid escaping from the impeller to enter a surrounding area which closely resembles the volute chambers common to conventional single stage centrifugal pumps.

Abstract: A positive displacement four-lobe impeller structure for use as a fluid driving or a fluid driven member or pump or generator is presented. The terminology pump is used to describe said structure subsequently. The pump comprises a symmetrical cylindrical housing having two 190.degree. arc cross-section interior walls separated by an inlet area and an outlet area. Inside the housing and disposed a selected distance apart therein are two cylindrical axially symmetric identical impellers. Each impeller comprises four interior concave arc sidewalls disposed 90.degree. apart and forming the base of four lobes. The concave arc side walls flow into and couple to exterior convex arc sidewalls which in turn flow into and connect to dual slightly extended tips. Each of said tips is separated from the opposite tip on the end of the lobe by an arc tip indentation. Each impeller is coaxial with the 190.degree.

Abstract: A semi-positive displacement pump of modular structure that includes a center plate, a pump defining housing removably secured to a first side thereof, a gear containing housing removably affixed to a second side, first and second impellers disposed in spaced relationship in the pump cavity between a fluid inlet and fluid outlet defined therein. The pump may be selectively driven either manually or by power means. The bottom of the pump chamber and the surface of the center plate most adjacent the pump chamber have first and second sets of aligned pressure relief cavities formed therein. The first and second impellers include first and second cylindrical hubs of substantial diameter that have their ends closely disposed to transverse center portions of the bottom of the pump chamber and center plate defined between the first and second pressure relief cavities formed therein.