Three concepts for variable displacement gear and gerotor pumps were proposed. CAD models and physical prototypes were built for demonstrating and understanding the concepts. One concept was taken to the stage of a working prototype. This was constructed using commonly available rapid prototyping techniques. Though it was a crude prototype, the device was found to be able to pump effectively, and the flow varied as expected when the displacement was varied.
The proposed concepts may be suitable for mass market applications such as automotive power steering and engine lubrication, and could provide very significant energy savings.