Heat engine based on shape memory alloys
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorDavid Goldstein
Life of this patent
Estimating the term…
Abstract
A tubular gear made of shape memory alloy in sheet form, having longitudi corrugations and being floatingly supported for rotation about an axis fixedly spaced from the rotational axis of a roller gear in meshing engagement with the corrugations. The tubular gear is sequentially deformed by exposure to radiated heat causing the shape memory alloy to expand circumferentially. Said meshing engagement with roller gear and such deformation of the tubular gear within differential temperature regions established by restricted exposure to the radiated heat; induces and sustains rotation of the tubular gear to convert the heat energy into mechanical energy.
Claims16
An engine for converting radiated heat energy into mechanical energy comprising a tube made of sheet material with shape memory properties having axially extending corrugations thereon, a toothed roller in meshing engagement with said corrugations within a cold thermal region, frame means for establishing a pair of fixedly spaced axes and means rotatively positioning the tube and the roller on said fixedly spaced axes restrictively exposing the corrugations to the radiated heat energy and producing a temperature differential with respect to the corrugations in said cold thermal region for inducing rotation of the tube and the roller about said fixedly spaced axes.
The combination of 3 wherein said roller includes rigie teeth having a pitch spacing less than of that the corrugations during said exposure thereof to the heat energy within the thermal heating region.
In combination with a source of radiated heat energy means for converting the heat energy into mechanical energy, comprising:
- a driven gear, frame means mounting the driven gear for rotation about an axis operatively oriented relative to said source, an energy input gear in meshing engagement with said driven gear and supporting means rotatively mounting the input gear on the frame means in said meshing engagement with the driven gear for establishing differential temperature regions on the input gear in response to exposure thereof to the radiated heat energy within one of said regions, said input gear comprising tubular means sequentially deformed in response to said exposure thereof to the radiated heat energy within said one of the regions and said meshing engagement thereof with the driven gear within the other of the differential temperature regions for maintaining said rotation of the driven gear.
In combination with a source of radiated heat energy, means for converting the heat energy into mechanical energy, comprising a pair of gears and frame means mounting said gears for rotation about fixedly spaced axes in operatively oriented relation to said source, one of said gears comprising tubular means rotatable about one of said axes for restricted exposure to the radiated heat energy within a thermal heating region and deformable means carried by the tubular means in meshing engagement with the other of the gears within a thermally colder region at a predetermined differential to said thermal heating region for inducing rotation of the gears about said fixedly spaced axes.
Dependencies are inferred from the claim text.