High efficiency digital hydraulic motor for kinetic energy recovery

"We aim to demonstrate a high power, high efficiency hydraulic motor based on our unique Digital Displacement (DD) technology, which will be suitable for application to hybrid systems in heavy duty vehicles such as delivery trucks, buses and commuter rail. In conjunction with a pneumatic accumulator, and an electronic controller integrated with the existing engine controller, the motor will form the heart of kinetic energy recovery system (KERS) with higher round-trip efficiency, higher power density and much lower cost than an equivalent electrical system based on ultracapacitor storage.
To be suitable for a commuter vehicle KERS, the DD motor requires innovation in the area of the embedded solenoid valves, and the local and system control software."