Heat exchanger integrated in a transmission

Abstract

A transmission ( 8 ) has a transmission case ( 26 ) that comprises an area in which the gear wheels ( 66, 68 ) rotate, and a heat exchanger ( 30 ) that absorbs heat generated in the transmission ( 8 ) and transferred to a transmission lubricant and conveys this heat to a coolant for transporting the heat away from the transmission ( 8 ). A recess ( 56 ), through which transmission lubricant flows and in which the heat exchanger ( 30 ) is arranged, is provided in the transmission case ( 26 ) outside the area in which the gear wheels ( 66, 68 ) rotate.

1 - 9 . (canceled)  
   
   
       10 . A transmission ( 8 ) having a transmission case ( 26 ), the transmission comprising an area in which gear wheels ( 66 ,  68 ) rotate, and a heat exchanger ( 30 ), the heat exchanger ( 30 ) absorbs heat generated in the transmission ( 8 ), transfers the heat to a transmission lubricant and conveys the heat to a coolant to transport the heat away from the transmission ( 8 ), a recess ( 56 ) through which the transmission lubricant flows and in which the heat exchanger ( 30 ) is arranged is provided in the transmission case ( 26 ) outside of the area in which the gear wheels ( 66 ,  68 ) rotate,.  
   
   
       11 . The transmission ( 8 ) of  claim 10 , wherein the heat exchanger ( 30 ) is a separate component that can be inserted in the recess ( 56 ) in the transmission case ( 26 ).  
   
   
       12 . The transmission ( 8 ) of  claim 10 , wherein the transmission lubricant flows through the recess ( 56 ) in the transmission case ( 26 ) at an intake side of an oil pump ( 62 ) transporting the transmission lubricant.  
   
   
       13 . The transmission ( 8 ) of  claim 10 , wherein a bypass valve ( 70 ) enables the heat exchanger ( 30 ) to be bypassed when the temperatures of the transmission lubricant drops below a specified limit, is provided at an intake side of an oil pump ( 62 ) transporting the transmission lubricant.  
   
   
       14 . The transmission ( 8 ) of  claim 10 , wherein the heat exchanger ( 30 ) in the recess ( 56 ) is accessible from outside of the case ( 26 ) for maintenance and assembly purposes.  
   
   
       15 . The transmission ( 8 ) of  claim 10 , wherein the heat exchanger ( 30 ) is configured as a tubular heat exchanger.  
   
   
       16 . The transmission ( 8 ) of  claim 10 , wherein the coolant is connected to a cooling unit ( 38 ) outside the transmission ( 8 ) for the purpose of transporting away the heat from the transmission ( 8 ).  
   
   
       17 . The transmission ( 8 ) of  claim 10 , wherein the coolant used to transport away the heat from the transmission ( 8 ) is a coolant in the cooling system of an internal combustion engine ( 4 ) that drives the transmission ( 8 ).  
   
   
       18 . The transmission ( 8 ) of  claim 10 , wherein the coolant is a water-based fluid and the transmission lubricant is an oil-based fluid.