Flammable refrigerant systems and compressors

Abstract

The systems and compressors for use with flammable refrigerants can include features that can reduce or address the generation of sparks or arcs internal or external to the compressor that could ignite the flammable refrigerant. The systems and compressors can also include features that can reduce or address leakage into or out of the hermetic compressor shell which could create a flammable atmosphere that could be ignited if the flammable atmosphere came into contact with an ignition source.

What is claimed is: 
     
         1 . A compressor comprising:
 a shell, the shell having an upper portion connected to a lower portion to form an enclosed space;   a compression mechanism, the compression mechanism being positioned in the lower portion of the shell; and   a motor connected to the compression mechanism by a shaft to power the compression mechanism, the motor comprising:
 a rotor connected to the shaft, the rotor being positioned in the upper portion of the shell; and 
 a stator to rotate the rotor, the stator being positioned outside of the upper portion of the shell. 
   
     
     
         2 . The compressor of  claim 1  wherein the stator is mounted on an outer surface of the upper portion of the shell. 
     
     
         3 . The compressor of  claim 1  wherein the upper portion of the shell comprises a non-magnetic material. 
     
     
         4 . The compressor of  claim 3  wherein the non-magnetic material comprises austenitic stainless steel, a polymer material, a ceramic material, or an epoxy material. 
     
     
         5 . The compressor of  claim 1  wherein the upper portion of the shell has a first material thickness and the lower portion of the shell has second material thickness greater than the first material thickness. 
     
     
         6 . The compressor of  claim 5  wherein the first material thickness is in the range of 0.02 inches to 0.1 inches. 
     
     
         7 . The compressor of  claim 1  further comprising a flange portion to connect the upper portion of the shell and the lower portion of the shell. 
     
     
         8 . The compressor of  claim 7  wherein the flange portion is integral and continuous with one of the upper portion of the shell or the lower portion of the shell. 
     
     
         9 . The compressor of  claim 8  wherein the flange portion is positioned at an angle with respect to the lower portion of the shell and is transverse to the lower portion of the shell. 
     
     
         10 . The compressor of  claim 1  further comprising at least one bearing positioned between the rotor and an inner surface of the upper portion of the housing. 
     
     
         11 . The compressor of  claim 1  wherein the upper portion of the shell has a first circumference and the lower portion of the shell has second circumference greater than the first circumference. 
     
     
         12 . A system comprising:
 a compressor, a condenser and an evaporator connected in a circuit and circulating a flammable refrigerant;   a motor connected to the compressor to power the compressor, the motor comprising a stator and a rotor;   the compressor comprising a compression mechanism and a shell, the shell having an upper portion connected to a lower portion, the compression mechanism being positioned in the lower portion of the shell;   the upper portion of the shell comprising a non-magnetic material;   the rotor being positioned in the upper portion of the shell; and   the stator being positioned outside the upper portion of the shell, the stator transmitting electromagnetic energy to the rotor.   
     
     
         13 . The system of  claim 12  wherein the stator is mounted on and in contact with an outer surface of the upper portion of the shell. 
     
     
         14 . The system of  claim 12  wherein the non-magnetic material comprises austenitic stainless steel, a polymer material, a ceramic material, or an epoxy material. 
     
     
         15 . The system of  claim 12  wherein the upper portion of the shell has a first material thickness and the lower portion of the shell has second material thickness greater than the first material thickness. 
     
     
         16 . The system of  claim 12  further comprising a flange portion to connect the upper portion of the shell and the lower portion of the shell. 
     
     
         17 . The system of  claim 16  wherein the flange portion is integral and continuous with one of the upper portion of the shell or the lower portion of the shell. 
     
     
         18 . The system of  claim 12  further comprising at least one bearing positioned between the rotor and an inner surface of the upper portion of the housing. 
     
     
         19 . The system of  claim 12  wherein the upper portion of the shell comprises a plurality of magnetic portions, each magnetic portion of the plurality of magnetic portions being separated by the non-magnetic portion. 
     
     
         20 . The system of  claim 12  further comprising a motor drive to operate the motor at variable speeds, the motor drive comprising an arc detect circuit breaker.