Energy harvesting system for a vehicle

A heat engine comprising:

• a plurality of first members;
• a plurality of second members disposed in spaced and alternating relationship to the plurality of first members;
• wherein each of the plurality of first members and the plurality of second members are rotatable;
• a shape memory alloy material forming a continuous loop;
• wherein the shape memory alloy material sequentially extends about the alternating plurality of first members and second members such that the shape memory alloy material operatively interconnects the plurality of first members and the plurality of second members;
• wherein each of the plurality of first members rotates in a first direction as each of the plurality of second members rotates in a second direction, opposite the first direction;
• wherein the shape memory alloy material is configured to selectively change crystallographic phase from martensite to austenite and thereby contract in response to exposure to a first temperature;
• and
• wherein the shape memory alloy material is also configured to selectively change crystallographic phase from austenite to martensite and thereby expand in response to exposure to a second temperature;
• and
• a tensioner configured to apply tension to the shape memory alloy material as the shape memory alloy material selectively expands and contracts, such that the shape memory alloy material is taut and at a predefined stress level;
• wherein the tensioner includes:
• a tensioning element configured to tension the shape memory alloy material;
• and
• a biasing device;
• wherein the biasing device is configured to bias the tensioning element into contact with the shape memory alloy material;
• and
• wherein the biasing device is formed from the shape memory alloy material in an austenitic state.

A heat engine comprising:

• a plurality of first members;
• a plurality of second members disposed in spaced and alternating relationship to the plurality of first members;
• wherein each of the plurality of first members and the plurality of second members are rotatable;
• a shape memory alloy material forming a continuous loop;
• wherein the shape memory alloy material sequentially extends about the alternating plurality of first members and second members such that the shape memory alloy material operatively interconnects the plurality of first members and the plurality of second members;
• wherein each of the plurality of first members rotate in a first direction as each of the plurality of second members rotates in a second direction, opposite the first direction;
• wherein the shape memory alloy material is configured to selectively change crystallographic phase from martensite to austenite and thereby contract in response to exposure to a first temperature;
• and
• wherein the shape memory alloy material is also configured to selectively change crystallographic phase from austenite to martensite and thereby expand in response to exposure to a second temperature;
• wherein each of the plurality of first members has a temperature that is substantially equal to one of the first temperature and the second temperature and each of the plurality of second members has a temperature that is substantially equal to the other of the first temperature and the second temperature;
• and
• a tensioner configured to radially move at least one of the plurality of first and second members to vary a distance between the plurality of first members and the plurality of second members to apply tension to the shape memory alloy material as the shape memory alloy material selectively expands and contracts such that the shape memory alloy material is taut and at a predefined stress level;
• wherein the tensioner includes a linear actuator operatively connected to each of the plurality of first and second members to radially move each of the plurality of first and second members with respect to the central axis to tension the shape memory alloy material.