Patent ID: 7774937

Claim:
A heat exchanger comprising: a shell having a first end and a second end; coolant chambers attached to the ends of the shell; the shell having an inner chamber defined by an inside wall surface; a tube stack disposed within the inner chamber and comprising a number of tubes arranged in a stack, the tubes including first and second ends; the tube stack extending beyond the ends of the shell and extending into the coolant chambers; the coolant chamber having a cross-sectional area greater than a cross-sectional area of the inner chamber and the coolant chamber comprising: a sidewall extending outwardly a distance from the tube stack; at least one divider extending into only a first one the coolant chambers from the sidewall of the coolant chamber toward a flattened one of the tubes and extending axially from a first end of the shell to an end of the coolant chamber that is distal from the shell; wherein the divider and the flattened one of the tubes form a partition through the coolant chamber; wherein a first portion of an inlet coolant passage is formed on one side of the partition and a first portion of an outlet coolant passage is formed on an opposite side of the partition; wherein a portion of the flattened tube extends axially from the coolant chamber to a second end of the shell to form a partition through the shell to form a second portion of the inlet coolant passage and a second portion of the outlet coolant passage; wherein the divider does not extend into the shell or the second one of the coolant chambers; and wherein a coolant inlet is in fluid flow communication with the inlet coolant passage, and a coolant outlet is in fluid flow communication with the outlet coolant passage.