Integrated multi-function return tube for combo heat exchangers

Abstract

A heat exchanger having an improved oil cooler section is provided. The oil cooler section includes a first manifold, a second manifold, an oil inlet port, an oil outlet port, cooling tubes, and a return tube. The first and second manifold are located in spaced relationship and the oil inlet and outlet port are located proximate each other toward one side of the heat exchanger. The cooling tubes are connected between the first and second manifold, each tube defining an oil flow passage. The return tube also be connected between the first and second manifold and defining an oil return passage. The oil return passage has a cross-sectional area larger than each of the oil flow passages allowing the oil to be returned along a low pressure flow path.

1 . A heat exchanger having an oil cooler section, the oil cooler section comprising: 
 a first manifold and a second manifold in spaced relationship;    an oil inlet port and an oil outlet port, wherein the oil inlet port is located proximate the oil outlet port;    a plurality of tubes, each tube defining an oil flow passage and having a first end connected to the first manifold with the oil flow passage in fluid communication therewith, and a second end connected to the second manifold with the oil flow passage in fluid communication therewith; and    a return tube defining an oil return passage, the return tube having a first end connected to the first manifold with the oil return passage in fluid communication therewith, and a second end connected to the second manifold with the oil return passage in fluid communication therewith, the oil return passage having a cross sectional area equal or larger than the summation of the cross sectional area of all the oil flow passages.    
     
     
         2 . The heat exchanger of  claim 1 , further comprising fins disposed between the plurality of tubes to enhance heat transfer.  
     
     
         3 . The heat exchanger of  claim 2 , wherein the fins are attached to the plurality of tubes to form a fin-tube assembly.  
     
     
         4 . The heat exchanger of  claim 3 , wherein the return tube is attached to the fin-tube assembly.  
     
     
         5 . The heat exchanger of  claim 4 , wherein the return tube has a flat portion and the flat portion of the return tube is attached to the fin-tube assembly.  
     
     
         6 . The heat exchanger of  claim 5 , wherein the return tube has a generally D-shaped cross section.  
     
     
         7 . The heat exchanger of  claim 1 , wherein the return tube includes a mounting flange.  
     
     
         8 . The heat exchanger of  claim 1 , wherein the oil inlet port is located on the return tube.  
     
     
         9 . The heat exchanger of  claim 1 , wherein the oil outlet port is located on the return tube.  
     
     
         10 . The heat exchanger of  claim 1 , wherein the return tube is comprised of Aluminum.  
     
     
         11 . The heat exchanger of  claim 1 , wherein the wall thickness of the return tube is configured to provide mechanical support to the heat exchanger.  
     
     
         12 . The heat exchanger of  claim 11 , wherein the wall thickness of the return tube is between 1.0 and 1.5 mm.  
     
     
         13 . The heat exchanger of  claim 1 , wherein the return tube has a circular portion at the first end of the return tube.  
     
     
         14 . A method of assembling a heat exchanger, the method comprising: 
 attaching fins between a plurality of tubes to form a fin-tube assembly;    attaching a return tube to the fin-tube assembly;    creating openings in a first manifold;    positioning the openings in the first manifold over the plurality of tubes and the return tube.    attaching the first manifold to the plurality of tubes and the return manifold.    
     
     
         15 . The method of  claim 14 , wherein attaching the first manifold to the plurality of tubes and the return tube includes brazing the first manifold to the plurality of tubes and the return tube.  
     
     
         16 . The method of  claim 14 , further comprising: 
 creating openings in a second manifold;    positioning the openings in the second manifold over the plurality of tubes and the return tube.    attaching the second manifold to the plurality of tubes and the return manifold.    
     
     
         17 . The method of  claim 16 , wherein attaching the second manifold to the plurality of tubes and the return tube includes brazing the first manifold to the plurality of tubes and the return tube.  
     
     
         18 . The method of  claim 16 , wherein the steps of attaching the first manifold and attaching the second manifold are performed at the same time.