Solid state engine using nitinol memory alloy
AssigneeThe United States of America as represented by the United States Department of Energy
InventorAhmad A. Golestaneh
Life of this patent
Estimating the term…
Abstract
A device for converting heat energy to mechanical energy includes a reservoir of a hot fluid and a rotor assembly mounted thereabove so a portion of it dips into the hot fluid. The rotor assembly may include a shaft having four spokes extending radially outwardly therefrom at right angles to each other, a floating ring and four flexible elements composed of a thermal memory material having a critical temperature between the temperature of the hot fluid and that of the ambient atmosphere extending between the ends of the spokes and the floating ring. Preferably, the flexible elements are attached to the floating ring through curved leaf springs. Energetic shape recovery of the flexible elements in the hot fluid causes the rotor assembly to rotate.
Claims17
A device for converting heat energy to mechanical energy comprising:
- a reservoir of fluid and
- a rotor assembly including
- a shaft,
- a floating ring encircling the shaft and
- a plurality of arcuate flexible elements composed of a shape-memory material having a critical temperature below that of the fluid temperature connecting the shaft and the floating ring disposed symmetrically about the rotor assembly so as to dip into the water on rotation of the rotor assembly,
- whereby energetic shape recovery of the thermal memory material in the reservoir displaces the center of mass of the rotor assembly to one side of the axis of rotation thereof so that the force of gravity acting on the floating ring causes the rotor assembly to turn and simultaneously deforms those arcuate elements in the atmosphere, readying them for further energetic shape recovery upon further rotation into the reservoir.
A device for converting heat energy of a fluid to mechanical energy comprising:
- a rotor assembly including a horizontal shaft, a plurality of spokes radiating from said shaft, a floating ring encircling said shaft at a location along its length spaced from said spokes, a plurality of arcuate flexible elements connecting said spokes to spaced points of attachment around said ring for support of said ring, said elements comprising a shape memory material having a critical temperature above which internal shape recovery forces are generated within said element,
- a reservoir of fluid at a temperature above the critical temperature of the shape memory material;
- said rotor assembly supported in respect to said reservoir such that a portion thereof including a fraction of said elements is immersed in said fluid at above the critical temperature to force said ring off center respecting said shaft as the shape memory material undergoes shape recovery and such that a portion thereof including a fraction of said elements are withdrawn from said fluid to permit deformation of said shape memory material at a temperature below the critical temperature whereby rotation is imparted to the rotor assembly.
Dependencies are inferred from the claim text.