Abstract: A fluid pump includes a pump head having an inlet for receiving fluid at a first pressure and an outlet for outputting fluid at a second pressure greater than the first pressure. Pressurized fluid is directed through a first passage to the outlet without the pressurized fluid leaving the pump head prior to reaching the outlet. A second passage directs pressurized fluid to a fluid circulation path which is at least partially external to the pump head with the fluid circulation path terminating adjacent the outlet. Pressurized fluid passing through the first and second passages is directed to the outlet without being re-pressurized by the pump head. The first and second passages are in opposed relation to one another to provide balancing of thrust produced by the flow of pressurized fluid through the passages. An electric motor drives the pump head. The fluid circulation path may include portions of the electric motor.

Abstract: A motor pump is provided in which the motor rotor is optimally force balanced for enhanced operation. The motor pump includes a pump head for pressurizing a fluid, and an electric motor drives the pump head. High pressure fluid is circulated through the motor air gap. The shaft of the motor rotor is axially movable with respect to the pump head such that the motor rotor is effectively floated in high pressure fluid as the fluid flows through the motor.