Project Leader: James Van de Ven, Professor of Mechanical Engineering & Eric Severson, Assistant Professor of Electrical and Computer Engineering
Institution: University of Minnesota & University of Wisconsin – Madison
Numerous mobile applications, from passenger vehicles to lawn mowers to Volvo’s compact excavator, are increasingly using electric power transmission in order to improve efficiency, reduce emissions, and reduce noise. However, for many functions of off-highway vehicles, the power/force density and robustness of hydraulics are required. In this project, a seamlessly integrated electric motor-hydraulic pump will be developed that efficiently and compactly converts electric to hydraulic power for a wide range of off-highway vehicle applications. While conventional electric to hydraulic conversion machines use a modular approach, integrating the functions into a single device eliminates energy conversion losses, improves compactness, and improves power density through hydraulic cooling of the electrical components. Two architectures of tightly integrated electric to hydraulic conversion machines will be investigated: a resonating linear design and a high-speed rotary design. The research tasks include constructing models that predicts the performance of the two architectures, selecting an architecture and refining the model, designing and fabricating a prototype, and demonstrating the prototype in a displacement control circuit. The performance targets for the machine are an electric to hydraulic conversion efficiency of 85%, power density of 5 kW/kg, and cost of $20/kW. Industry experience with hydraulic and electric machines is provided by our industry partners Eaton Corporation and Windings Inc.