An integral axial-field motor pump, includes a housing assembly having a working fluid inlet, a working fluid discharge, and a stationary shaft mounted therein. A motor stator is mounted in the housing assembly radially surrounding the stationary shaft and having a seal to prevent exposure to the working...http://www.google.ca/patents/US6012909?utm_source=gb-gplus-sharePatent US6012909 - Centrifugal pump with an axial-field integral motor cooled by working fluid
