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Title: Memory alloy heat engine and method of operation

Abstract

A heat engine and method of operation employing an alloy having a shape memory effect. A memory alloy element such as one or more wire loops are cyclically moved through a heat source, along a path toward a heat sink, through the heat sink and then along another path in counter-flow heat exchange relationship with the wire in the first path. The portion of the wire along the first path is caused to elongate to its trained length under minimum tension as it is cooled. The portion of the wire along the second path is caused to contract under maximum tension as it is heated. The resultant tension differential between the wires in the two paths is applied as a force through a distance to produce mechanical work. In one embodiment a first set of endless memory alloy wires are reeved in non-slip engagement between a pair of pulleys which are mounted for conjoint rotation within respective hot and cold reservoirs. Another set of endless memory alloy wires are reeved in non-slip engagement about another pair of pulleys which are mounted in the respective hot and cold reservoirs. The pulleys in the cold reservoir are of a larger diameter thanmore » those in the hot reservoir and the opposite reaches of the wires between the two sets of pulleys extend in closely spaced-apart relationship in counter-flow heat regenerator zones. The pulleys are turned to move the two sets of wires in opposite directions. The wires are stretched as they are cooled upon movement through the heat regenerator toward the cold reservoirs, and the wires contract as they are heated upon movement through the regenerator zones toward the hot reservoir. This contraction of wires exerts a larger torque on the greater diameter pulleys for turning the pulleys and supplying mechanical power. Means is provided for applying a variable tension to the wires. Phase change means is provided for controlling the angular phase of the pulleys of each set for purposes of start up procedure as well as for optimizing engine operation under varying conditions of load, speed and temperatures.« less

Inventors:
 [1]
  1. 2108 41ST Ave., Oakland, CA 94601
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
862950
Patent Number(s):
4055955
Assignee:
Johnson, Alfred Davis (2108 41ST Ave., Oakland, CA 94601)
Patent Classifications (CPCs):
F - MECHANICAL ENGINEERING F03 - MACHINES OR ENGINES FOR LIQUIDS F03G - SPRING, WEIGHT, INERTIA OR LIKE MOTORS
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
memory; alloy; heat; engine; method; operation; employing; shape; effect; element; wire; loops; cyclically; moved; source; path; sink; counter-flow; exchange; relationship; portion; caused; elongate; trained; length; minimum; tension; cooled; contract; maximum; heated; resultant; differential; wires; paths; applied; force; distance; produce; mechanical; embodiment; set; endless; reeved; non-slip; engagement; pair; pulleys; mounted; conjoint; rotation; respective; hot; cold; reservoirs; reservoir; larger; diameter; opposite; reaches; sets; extend; closely; spaced-apart; regenerator; zones; move; directions; stretched; movement; contraction; exerts; torque; supplying; power; means; provided; applying; variable; phase; change; controlling; angular; purposes; start; procedure; optimizing; varying; conditions; load; speed; temperatures; spaced-apart relationship; wire loop; opposite direction; memory alloy; opposite directions; heat engine; heat sink; phase change; heat exchange; heat source; exchange relationship; closely spaced; shape memory; exchange relation; larger diameter; mechanical power; variable tension; wire loops; alloy wires; apart relationship; produce mechanical; apart relation; spaced-apart relation; closely spaced-apart; operation employing; memory effect; heat regenerator; flow heat; alloy heat; /60/

Citation Formats

Johnson, Alfred Davis. Memory alloy heat engine and method of operation. United States: N. p., 1977. Web.
Johnson, Alfred Davis. Memory alloy heat engine and method of operation. United States.
Johnson, Alfred Davis. Sat . "Memory alloy heat engine and method of operation". United States. https://www.osti.gov/servlets/purl/862950.
@article{osti_862950,
title = {Memory alloy heat engine and method of operation},
author = {Johnson, Alfred Davis},
abstractNote = {A heat engine and method of operation employing an alloy having a shape memory effect. A memory alloy element such as one or more wire loops are cyclically moved through a heat source, along a path toward a heat sink, through the heat sink and then along another path in counter-flow heat exchange relationship with the wire in the first path. The portion of the wire along the first path is caused to elongate to its trained length under minimum tension as it is cooled. The portion of the wire along the second path is caused to contract under maximum tension as it is heated. The resultant tension differential between the wires in the two paths is applied as a force through a distance to produce mechanical work. In one embodiment a first set of endless memory alloy wires are reeved in non-slip engagement between a pair of pulleys which are mounted for conjoint rotation within respective hot and cold reservoirs. Another set of endless memory alloy wires are reeved in non-slip engagement about another pair of pulleys which are mounted in the respective hot and cold reservoirs. The pulleys in the cold reservoir are of a larger diameter than those in the hot reservoir and the opposite reaches of the wires between the two sets of pulleys extend in closely spaced-apart relationship in counter-flow heat regenerator zones. The pulleys are turned to move the two sets of wires in opposite directions. The wires are stretched as they are cooled upon movement through the heat regenerator toward the cold reservoirs, and the wires contract as they are heated upon movement through the regenerator zones toward the hot reservoir. This contraction of wires exerts a larger torque on the greater diameter pulleys for turning the pulleys and supplying mechanical power. Means is provided for applying a variable tension to the wires. Phase change means is provided for controlling the angular phase of the pulleys of each set for purposes of start up procedure as well as for optimizing engine operation under varying conditions of load, speed and temperatures.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1977},
month = {1}
}

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