Fuel- or oil gear pump used in vehicles, has gear wheels with plastic surfaces having same coefficient of thermal expansion as metal casing

摘要

The displacement components, i.e. the gear wheels, have a plastic surface. The plastic has essentially the same coefficient of thermal expansion as the metallic material of the pump casing. The pump components comprise a rotor, a contour ring and one or more blades or impellers. An Independent claim is included for the corresponding pump.