Heat transfer device

Abstract

A heat transfer device for an internal combustion engine includes an outer housing comprising an inner wall. An inner housing comprises a partition wall which comprises an outer surface. The inner housing separates an inner duct, which has a fluid to be cooled flow therethrough, from an outer coolant duct, which is formed between the inner housing and the outer housing. Fins extend from the partition wall into the inner duct. Recesses are formed on the outer surface. An inner wall is formed on a surface of the outer housing facing the coolant duct. Projections extend from the inner wall. The projections extend towards the recess on the partition wall so that a cross section of the coolant duct is substantially constant. The projections on the inner wall of the outer housing are formed by beads on the outer housing.

What is claimed is: 
     
         1 - 7 . (canceled) 
     
     
         8 . A heat transfer device for an internal combustion engine, the heat transfer unit comprising:
 an outer housing comprising an inner wall;   an inner housing comprising a partition wall which comprises an outer surface, the inner housing being configured to separate an inner duct, which is configured to have a fluid to be cooled flow therethrough, from an outer coolant duct, which is formed between the inner housing and the outer housing;   fins extending from the partition wall into the inner duct;   recesses formed on the outer surface;   an inner wall formed on a surface of the outer housing facing the coolant duct; and   projections extending from the inner wall, the projections being arranged to extend towards the recess on the partition wall so that a cross section of the coolant duct is substantially constant, the projections on the inner wall of the outer housing being formed by beads on the outer housing.   
     
     
         9 . The heat transfer device as recite in  claim 8 , wherein each of the fins comprise a fin base, and each of the recesses are formed between a respective fine base. 
     
     
         10 . The heat transfer device as recited in  claim 9 , wherein each of the recesses are formed at a respective fin base. 
     
     
         11 . The heat transfer device as recited in  claim 8 , wherein the fins are arranged in rows one behind the other in a flow direction of the fluid to be cooled, the fins of successive rows being arranged offset to each other, and the beads being formed to correspond to the offset. 
     
     
         12 . The heat transfer device as recited in  claim 8 , wherein the outer surface of the inner housing facing the coolant duct, and the inner wall of the outer housing facing the coolant duct, are each formed so as to be continuous. 
     
     
         13 . The heat transfer device as recited in  claim 8 , wherein the inner housing is manufactured in a die-casting process. 
     
     
         14 . The heat transfer device as recited in  claim 8 , wherein the outer housing is manufactured in a sandcasting process.