Patent ID: 7077776

Claim:
A system for heating transmission fluid, comprising: an oil pan secured to a transmission case for containing hydraulic fluid, including a surface at least partially enclosing the fluid within the oil pan; a supply duct for carrying exhaust gas from an engine; a heat exchanger secured to the oil pan, communicating through a first connection with the supply duct, and defining a flow path of exhaust gas along the surface through the heat exchanger for transferring heat from the exhaust gas to fluid contained in the oil pan, the heat exchanger further comprising surfaces enclosing the exhaust gas in the heat exchanger, the heat exchanger having an opening bounded by the enclosing surfaces, the opening being at least partially closed by the surface of the oil pan; an inlet port passing through a surface of the heat exchanger and communicating with the supply duct; an exhaust port passing through a surface of the heat exchanger and communicating with the supply duct; and a baffle located between the inlet part and exhaust port for directing flow of exhaust gas in the heat exchanger along the surface of the oil pan; an exhaust duct communicating through a second connection with the supply duct, and connected to the heat exchanger for carrying engine exhaust gas from the heat exchanger to the supply duct; and a valve located between the first connection and second connection for opening and closing the supply duct to the flow of exhaust gas between the first connection and second connection.