Method of starting and operating a shape memory alloy heat engine

US8800283B2 · kind B2 · utility

Assignees

• GM GLOBAL TECHNOLOGY OPERATIONS LLC · US
• Dynalloy, Inc. · US
• THE REGENTS OF THE UNIVERSITY OF MICHIGAN · US

Inventors

• Alan L. Browne · Grosse Pointe, US
• Nancy L. Johnson · Northville, US
• Nilesh D. Mankame · Ann Arbor, US
• Paul W. Alexander · Ypsilanti, US
• John Andrew Shaw · Toronto, CA
• Christopher B. Churchill · Ventura, US
• Andrew C. Keefe · Calabasas, US
• Guillermo A. Herrera · Calabasas, US
• Jeffrey W. Brown · Los Gatos, US
• Richard J. Skurkis · Lake Orion, US

Key dates

• Filing date: Dec 30, 2011
• Grant date: Aug 12, 2014
• Expiry date: Apr 22, 2032

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F03G7/0641
• WIPO field: Engines, pumps, turbines
• WIPO sector: Mechanical engineering

Abstract

A shape memory alloy (SMA) heat engine includes a first rotatable pulley, a second rotatable pulley, and an SMA material disposed about the first and second rotatable pulleys and between a hot region and a cold region. A method of starting and operating the SMA heat engine includes detecting a thermal energy gradient between the hot region and the cold region using a controller, decoupling an electrical generator from one of the first and second rotatable pulleys, monitoring a speed of the SMA material about the first and second rotatable pulleys, and re-engaging the driven component if the monitored speed of the SMA material exceeds a threshold. The SMA material may selectively change crystallographic phase between martensite and austenite and between the hot region and the cold region to convert the thermal gradient into mechanical energy.