Method and apparatus to transfer heat to automatic transmission fluid using engine exhaust gas feed stream

Abstract

Transmission fluid is heated through a heat exchanger effective to transfer heat between transmission fluid of a transmission assembly and an exhaust gas feed stream of an engine.

1 . Apparatus for heating transmission fluid, comprising:
 a heat exchanger effective to transfer heat between transmission fluid of a transmission assembly and an exhaust gas feed stream of an engine; and   a flow valve for selectively controlling flow of said exhaust gas feed stream through said heat exchanger based upon temperature of said transmission fluid.   
     
     
         2 . The apparatus of  claim 1 , wherein said flow valve is electrically actuated. 
     
     
         3 . The apparatus of  claim 1 , wherein said flow valve is mechanically actuated. 
     
     
         4 . The apparatus of  claim 1 , wherein said heat exchanger is thermally coupled to a sump of said transmission assembly. 
     
     
         5 . The apparatus of  claim 4 , wherein said exhaust gas feed stream comprises an exhaust gas recirculation feed stream. 
     
     
         6 . The apparatus of  claim 1 , wherein said heat exchanger is thermally coupled to an exhaust pipe. 
     
     
         7 . A method for heating transmission fluid with an exhaust gas feed stream from an engine, comprising:
 selectively operating an exhaust gas flow valve based upon temperature of transmission fluid from a transmission assembly; and   diverting with said flow valve some portion of the exhaust gas feed stream from the engine into a heat exchanger to thermally couple said exhaust gas feed stream to said transmission fluid.   
     
     
         8 . The method of  claim 7 , wherein operation of said flow valve is accomplished electronically. 
     
     
         9 . The method of  claim 7 , wherein operation of said flow valve is accomplished mechanically. 
     
     
         10 . The method of  claim 7 , wherein the portion of the exhaust gas feed stream diverted into the heat exchanger is recirculated into an intake manifold of the engine.