Compact, high efficiency, smart material actuated hydraulic pump

Abstract

The invention disclosed is a compact, high efficiency, smart material element driven hydraulic pump comprising a diaphragm, a face plate coupled to and spanning across the diaphragm, and a smart material element. The diaphragm comprises on a first side a recess and a stiff face-seal surface surrounding the recess. On the second side of the diaphragm is a stiff center pedestal and a flexure means attached to the periphery of the center pedestal. The diaphragm and face plate coupled together form a chamber that is dynamically sealed by contact of the face-seal surface against the face plate and such chamber's compliance is primarily and effectively within the flexure means within the diaphragm. A smart material element is positioned and constrained against the stiff center pedestal such that extension and contraction of the smart material element deforms the diaphragm such that the pumping chamber compresses and expands through compliance and deformation within the flexure means alone. In a preferred form the flexure means is comprised of two annular flexures and the recess is of conical edge shape such that the chamber flattens against the face plate to effect a broad, low profile pump chamber having negligible seal compliance and providing high volumetric efficiency.