Light Weight Crankcase Casting for Compressor

Abstract

A compressor, as well as a lightweight and strong casting for a compressor, are disclosed. The compressor, which may be a reciprocating compressor for use in compressing high-pressure refrigerants such as CO 2 , includes substantially reduced wall thicknesses (t) compared to prior art castings. The side walls of the compressor can be manufactured to such reduced thicknesses (t) through the use of a bridge spanning across the crankcase. This not only allows the opposing side walls to be manufactured of a thinner material, but the bottom cover removably mounted to the crankcase can be manufactured from a thinner and lighter material as well. Through the use of such a bridge, the resulting compressor is not only able to satisfy current strength requirements, but at significant weight, size and cost savings as well.

1 . A compressor, comprising:
 a motor;   a compression element operatively associated with the motor; and   a housing surrounding the motor and compression element, at least one bridge extending between opposing side walls of the housing proximate the compression element, the bridge being integrally cast with the housing.   
     
     
         2 . The compressor of  claim 1 , wherein the housing includes side walls having a maximum wall thickness (t) of twenty-five millimeters. 
     
     
         3 . The compressor of  claim 1 , wherein the compressor further includes a working fluid to be compressed, the working fluid being a refrigerant. 
     
     
         4 . The compressor of  claim 3 , wherein the refrigerant is carbon dioxide. 
     
     
         5 . The compressor of  claim 3 , wherein the refrigerant is compressed to an operating pressure of at least 500 psi. 
     
     
         6 . The compressor of  claim 5 , wherein the housing has a burst pressure at least five times the operating pressure. 
     
     
         7 . The compressor of  claim 1 , wherein the housing ( 22 ) includes a crankcase, connecting rods and a drive shaft moving within the crankcase, the bridge extending across the crankcase. 
     
     
         8 . The compressor of  claim 1 , further including a bottom cover ( 66 ) removable from the crankcase, the bridge extending across and in contact with the bottom cover. 
     
     
         9 . The compressor of  claim 1 , wherein the compressor is a reciprocating compressor. 
     
     
         10 . The compressor of  claim 8 , wherein the compression element is a piston. 
     
     
         11 . The compressor of  claim 1 , wherein the housing is made of gray cast iron. 
     
     
         12 . The compressor of  claim 2 , wherein the side walls have a wall thickness (t) of between sixteen and twenty-five millimeters. 
     
     
         13 . A casting for use with a refrigerant compressor, comprising:
 a motor compartment adapted to house a motor;   a crankcase compartment integral with the motor compartment and adapted to house at least one moving compression element; and   a bridge spanning across the crankcase compartment, the motor compartment, crankcase compartment and bridge being cast as one integral piece.   
     
     
         14 . The casting of  claim 13 , where the crankcase compartment is closed by a removable cover, the bridge extending across and in contact with the removable cover when the removable cover is attached to the casting. 
     
     
         15 . The casting of  claim 13 , wherein the casting is made of gray cast iron. 
     
     
         16 . The casting of  claim 13 , wherein the refrigerant compressor compresses refrigerant to an operating pressure, the casting having a burst pressure of at least five times the operating pressure. 
     
     
         17 . The casting of  claim 13 , wherein the crankcase compartment includes side walls with a maximum wall thickness (t) of twenty-five millimeters. 
     
     
         18 . The casting of  claim 17 , wherein the side walls have a thickness (t) between sixteen and twenty-five millimeters.