Heat exchanger

Abstract

A heat exchanger includes a working fluid inlet configured to receive a working fluid, a working fluid outlet in fluid communication with the working fluid inlet, a coolant inlet configured to receive a coolant, a coolant outlet in fluid communication with the coolant inlet, a first plate, a second plate stacked on the first plate to define a working fluid channel between the first plate and the second plate, a third plate stacked on the second plate to define a coolant channel between the second plate and the third plate, a fourth plate stacked on the third plate, and a reinforcement plate positioned in the coolant channel. The coolant is configured to reduce a temperature of the working fluid as the coolant flows through the coolant channel. The reinforcement plate includes a first surface brazed to the second plate and a second surface brazed to the third plate.

What is claimed is: 
     
         1 . A heat exchanger comprising:
 a working fluid inlet configured to receive a working fluid;   a working fluid outlet in fluid communication with the working fluid inlet;   a coolant inlet configured to receive a coolant;   a coolant outlet in fluid communication with the coolant inlet;   a first plate;   a second plate stacked on the first plate to define a working fluid channel between the first plate and the second plate, the working fluid channel providing fluid communication of the working fluid between the working fluid inlet and the working fluid outlet;   a third plate stacked on the second plate to define a coolant channel between the second plate and the third plate, the coolant channel providing fluid communication of the coolant between the coolant inlet and the coolant outlet, the coolant configured to reduce a temperature of the working fluid as the coolant flows through the coolant channel;   a fourth plate stacked on the third plate, the working fluid channel further defined between the third plate and the fourth plate; and   a reinforcement plate positioned in the coolant channel, the reinforcement plate including a first surface and a second surface opposite the first surface, the first surface brazed to the second plate, the second surface brazed to the third plate.   
     
     
         2 . The heat exchanger of  claim 1 , wherein
 the second plate includes a plurality of first dimples extending into the coolant channel,   the third plate includes a plurality of second dimples extending into the coolant channel, and   each first dimple engages one respective second dimple.   
     
     
         3 . The heat exchanger of  claim 2 , wherein the reinforcement plate includes a plate aperture extending through the reinforcement plate, and wherein one first dimple and one second dimple are positioned in the plate aperture. 
     
     
         4 . The heat exchanger of  claim 2 , wherein the reinforcement plate includes a notch on an outer surface of the reinforcement plate, and wherein one first dimple and one second dimple are positioned in the notch. 
     
     
         5 . The heat exchanger of  claim 4 , wherein the notch is a first notch of a plurality of notches on the outer surface of the reinforcement plate, and wherein one first dimple and one second dimple are positioned in each notch of the plurality of notches. 
     
     
         6 . The heat exchanger of  claim 1 , wherein
 the second plate defines a first outer edge,   the third plate defines a second outer edge, and   the reinforcement plate is spaced apart from the first outer edge and the second outer edge by a distance to minimize stress at the first outer edge and the second outer edge.   
     
     
         7 . The heat exchanger of  claim 1 , wherein
 the reinforcement plate is a first reinforcement plate,   the heat exchanger further comprises a second reinforcement plate positioned between the second plate and the third plate,   the first reinforcement plate is positioned adjacent the working fluid inlet, and   the second reinforcement plate is positioned adjacent the working fluid outlet.   
     
     
         8 . The heat exchanger of  claim 1 , wherein
 the heat exchanger further includes a fifth plate stacked on the fourth plate, the coolant channel further defined between the fourth plate and the fifth plate,   the reinforcement plate is a first reinforcement plate, and   the heat exchanger further comprises a third reinforcement plate positioned in the coolant channel, the third reinforcement plate engaging the fourth plate and the fifth plate.   
     
     
         9 . The heat exchanger of  claim 1 , wherein the reinforcement plate, the second plate, and the third plate are composed of the same material. 
     
     
         10 . The heat exchanger of  claim 1 , wherein the working fluid is motor oil. 
     
     
         11 . The heat exchanger of  claim 1 , wherein
 the reinforcement plate defines an area,   the second plate defines an area, and   the area of the reinforcement plate is less than 10% the area of the second plate.   
     
     
         12 . The heat exchanger of  claim 1 , further comprising a copper foil frame between the second plate and the third plate, the copper foil frame configured to provide a filler metal for brazing the second plate to the third plate. 
     
     
         13 . The heat exchanger of  claim 12 , wherein the copper foil frame is positioned between the second plate and the reinforcement plate. 
     
     
         14 . The heat exchanger of  claim 12 , wherein the copper foil frame includes a body and a recessed portion recessed relative to the body, and wherein the reinforcement plate is positioned in the recessed portion to assist with positioning the reinforcement plate in the coolant channel. 
     
     
         15 . The heat exchanger of  claim 14 , wherein the recessed portion includes a foil aperture, and wherein the second plate includes a dimple received in the foil aperture to allow the recessed portion to engage a surface of the second plate.