A Compact Hydrostatic-Driven Electric Generator: Design, Prototype, and Experiment

This paper presents an integrated hydrostatic-driven electric generator, which can be employed to convert hydrostatic energy to electrical form directly. The machine with compact structure is realized by mounting a Halbach permanent magnet array which has self-shielding magnetic property on the barrel surface of an axial piston hydrostatic motor. A stator consisting of iron core and windings is installed concentrically on the outside of the permanent magnets. Then, according to electromagnetic theory, electrical power will be generated when the barrel and the magnets are driven to rotate by pressurized fluid. Parametric constraints required by the integration are analyzed and tradeoff designs of some significant parameters are implemented by using theoretical analysis and finite-element analysis. A prototype is fabricated based on the utilization of some standard parts, and tested under both of no-load and loaded conditions. The results demonstrate that the prototype has expected performances including small volume and moment of inertia, reasonable efficiency, as well as good output voltage stiffness and generation quality.