A positive-displacement rotary pump comprising a pair of meshing gears (13, 14) or rotors, consisting of a driving gear and a driven gear, contained in a shell (10) having an output opening and an intake opening for a fluid. The gears (13, 14) include shafts (23, 24) which are supported by bushings (15a,...http://www.google.co.uk/patents/US6887055?utm_source=gb-gplus-sharePatent US6887055 - Positive-displacement rotary pump
