# US 8,769,946 B2 · Cooling system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,769,946 B2 - Document ID: US8769946B2 - Status: Granted - Kind: B2 - Application number: 12/947,857 - Filed: 2010-11-17 - Published: 2011-05-26 - Granted: 2014-07-08 - Earliest claimed: 2009-11-20 - Assignees: GM Global Technology Operations LLC - Applicants: Paul W. Alexander; Alan L. Browne; Nancy L. Johnson; Patrick B. Usoro; Nilesh D. Mankame; Xiujie Gao; Geoffrey P. McKnight; John A. Cafeo; Christopher P. Henry - Inventors: Paul W. Alexander; Alan L. Browne; Nancy L. Johnson; Patrick B. Usoro; Nilesh D. Mankame; Xiujie Gao; Geoffrey P. McKnight; John A. Cafeo; Christopher P. Henry - Web page: https://patentgrep.com/patent/US8769946B2 ## CPC - F03G 7/06143: {Wires} - F03G 7/0641: {Motors; Energy harvesting or waste energy recovery} - F03G 7/066: {Actuator control or monitoring} - F03G: SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR (arrangements in connection with power supply in vehicles from force of nature B60K16/00; electric propulsion with power supply in vehicles from force of nature B60L8/00) ## Abstract A cooling system configured for converting thermal energy to mechanical energy includes a source of thermal energy provided by a temperature difference between a heat source having a first temperature and a coolant having a second temperature that is lower than the first temperature. The cooling system includes a cooling circuit configured for conveying the coolant to and from the heat source. The cooling circuit includes a conduit and a pump in fluid communication with the conduit and configured for delivering the coolant to the heat source. The cooling system also includes a heat engine disposed in thermal relationship with the conduit and configured for converting thermal to mechanical energy. The heat engine includes a first element formed from a first shape memory alloy having a crystallographic phase changeable between austenite and martensite at a first transformation temperature in response to the temperature difference between the heat source and coolant. ## Claims ### Claim 1 A cooling system configured for converting thermal energy to mechanical energy, the cooling system comprising: a source of thermal energy provided by a temperature difference between a heat source having a first temperature and a coolant having a second temperature that is lower than said first temperature; a cooling circuit configured for conveying said coolant to and from said heat source and including; a conduit; and a pump in fluid communication with said conduit and configured for delivering said coolant to said heat source; a heat engine disposed in thermal relationship with said conduit and configured for converting thermal energy to mechanical energy, wherein said heat engine includes a first element formed from a first shape memory alloy having a crystallographic phase changeable between austenite and martensite at a first transformation temperature in response to said temperature difference between said heat source and said coolant; and a member formed from a conductive material and disposed in contact with said conduit so that said member abuts said conduit and transfers thermal energy from said conduit to said first element via conduction; wherein said member includes a plurality of flexible bristles extending away from said conduit and disposed in contact with said first element. ### Claim 2 (depends on 1) The cooling system of claim 1, wherein said first shape memory alloy changes crystallographic phase from martensite to austenite to thereby dimensionally contract at a localized region in response to said heat source. ### Claim 3 (depends on 2) The cooling system of claim 2, wherein said first shape memory alloy changes crystallographic phase from austenite to martensite to thereby dimensionally expand at said localized region in response to said coolant. ### Claim 4 (depends on 3) The cooling system of claim 3, wherein said first shape memory alloy alternately dimensionally expands at said localized region in response to said second temperature and dimensionally contracts at said localized region in response to said first temperature to thereby convert thermal energy to mechanical energy. ### Claim 5 (depends on 1) The cooling system of claim 1, further including an insulator disposed in contact with said conduit and configured for thermally insulating said conduit. ### Claim 6 (depends on 1) The cooling system of claim 1, further including a plurality of heat engines. ### Claim 7 (depends on 6) The cooling system of claim 6, wherein said plurality of heat engines is arranged in series along said conduit. ### Claim 8 (depends on 1) The cooling system of claim 1, wherein said first element further has at least a second transformation temperature along a thickness of said first element at which said crystallographic phase changes between austenite and martensite. ### Claim 9 (depends on 1) The cooling system of claim 1, further including at least a second element formed from a second shape memory alloy having a crystallographic phase changeable between austenite and martensite at a second transformation temperature in response to said temperature difference between said heat source and said coolant. ### Claim 10 (depends on 1) The cooling system of claim 1, further including a generator configured for converting mechanical energy to electricity, wherein said generator is driven by said heat engine. ### Claim 11 (depends on 10) The cooling system of claim 10, wherein said first shape memory alloy alternately dimensionally expands at a localized region in response to said second temperature and dimensionally contracts at another localized region in response to said first temperature to thereby convert thermal energy to mechanical energy and drive said generator. ### Claim 12 A cooling system configured for converting thermal energy to mechanical energy, the cooling system comprising: a source of thermal energy provided by a temperature difference between a heat source having a first temperature and a coolant having a second temperature that is lower than said first temperature; a cooling circuit configured for conveying said coolant to and from said heat source and including; a conduit configured for recirculating said coolant in a closed loop within said cooling circuit; and a pump in fluid communication with said conduit and configured for delivering the coolant to said heat source; a heat engine disposed in thermal relationship with said conduit and configured for converting thermal energy to mechanical energy, wherein said heat engine includes a first element formed from a first shape memory alloy having a crystallographic phase changeable between austenite and martensite at a first transformation temperature in response to said temperature difference between said heat source and said coolant; a member formed from a conductive material and disposed in contact with said conduit so that said member abuts said conduit and transfers thermal energy from said conduit to said first element via conduction, wherein said member includes a plurality of flexible bristles extending away from said conduit and disposed in contact with said first element to thereby change said crystallographic phase between austenite and martensite; an insulator disposed in contact with said conduit and said member and configured for thermally insulating said conduit and said member; and a generator configured for converting mechanical energy to electricity, wherein said first shape memory alloy alternately dimensionally expands at a localized region in response to said second temperature and dimensionally contracts at another localized region in response to said first temperature to thereby convert thermal energy to mechanical energy and drive said generator. ### Claim 13 A cooling system configured for converting thermal energy to mechanical energy, the cooling system comprising: a source of thermal energy provided by a temperature difference between a heat source having a first temperature and a coolant having a second temperature that is lower than said first temperature; a cooling circuit configured for conveying said coolant to and from said heat source and including; a conduit; and a pump in fluid communication with said conduit and configured for delivering said coolant to said heat source; a heat engine disposed in thermal relationship with said conduit and configured for converting thermal energy to mechanical energy, wherein said heat engine includes a first element formed from a first shape memory alloy having a crystallographic phase changeable between austenite and martensite at a first transformation temperature in response to said temperature difference between said heat source and said coolant; a member formed from a conductive material and disposed in contact with said conduit so that said member abuts said conduit and transfers thermal energy from said conduit to said first element via conduction; wherein said member includes a plurality of flexible bristles extending away from said conduit and disposed in contact with said first element; and a radiator in fluid communication with said heat source and said heat engine and configured for dissipating thermal energy from said coolant. ### Claim 14 (depends on 13) The cooling system of claim 13, wherein said first shape memory alloy alternately dimensionally expands at a localized region in response to said second temperature and dimensionally contracts at said localized region in response to said first temperature to thereby convert thermal energy to mechanical energy. ### Claim 15 (depends on 14) The cooling system of claim 14, further including a generator configured for converting mechanical energy to electricity, wherein said generator is driven by said heat engine. ### Claim 16 (depends on 13) The cooling system of claim 13, wherein said coolant recirculates within said cooling circuit in a closed loop.