Miniature rotary compressor, and methods related thereto

Abstract

Disclosed is a rolling piston rotary compressor for use with primary refrigerants that is miniaturized for portable and mobile applications for which size and weight are often crucial. The miniature rotary compressor comprises a compressor mechanism, a brushless DC motor and a casing. The compressor mechanism comprises, a cylinder, a shaft having an eccentric part, one or more bearings to support the shaft, a roller, a vane, an oil sump, openings for communicating with lubricant oil and refrigerant, and inlet and discharge ports. The compressor mechanism and the motor are housed in a hermetically sealed or semi-hermetically sealed casing. The configuration and design of the present invention allow the realization of an ultralight miniature compressor. The miniature rotary compressor provides a higher power density and comparable efficiency as compared to state-of-the-art refrigerant-based rotary compressors. Also disclosed are methods of manufacturing the miniature rotary compressor.

1 . A miniature rolling piston rotary compressor assembly, comprising a compressor mechanism, a brushless DC motor, and a casing, wherein the compressor assembly comprises an axial length of up to about 3.5 in.  
   
   
       2 . A miniature rolling piston rotary compressor assembly according to  claim 1 , wherein the compressor assembly comprises a diameter of up to about 2.5 in.  
   
   
       3 . A miniature rolling piston rotary compressor assembly according to  claim 1 , wherein the compressor assembly comprises a displacement of up to about 3.0 cc/revolution.  
   
   
       4 . A miniature rolling piston rotary compressor assembly according to  claim 1 , wherein the compressor assembly weighs up to about 1.7 pounds.  
   
   
       5 . A miniature rolling piston rotary compressor assembly according to  claim 1 , further comprising a discharge muffler comprising radial holes for oil separation.  
   
   
       6 . A miniature rolling piston rotary compressor assembly according to  claim 1 , wherein the casing is hermetically sealed.  
   
   
       7 . A miniature rolling piston rotary compressor assembly according to  claim 1 , further comprising three housing sections, wherein said housing sections are joined via plasma welding.  
   
   
       8 . A miniature rolling piston rotary compressor assembly according to  claim 1 , wherein the casing is semi-hermetically sealed.  
   
   
       9 . A miniature rolling piston rotary compressor assembly according to  claim 1 , wherein the miniature rotary compressor comprises a cooling power density in the range of from about 23.6 watts/in 3  to about 36.9 watts/in 3 , or a cooling power density in the range of from about 200.00 watts/lb to about 312.50 watts/lb.  
   
   
       10 . A miniature rolling piston rotary compressor assembly according to  claim 1 , wherein the miniature rotary compressor comprises COP in the range of from about 1.85 to about 2.25 at evaporator temperature of about 55° F. and condenser temperature of about 150° F., or in the range of about 3.8 to about 4.6 at evaporator temperature of about 55° F. and condenser temperature of about 110° F.  
   
   
       11 . A miniature rolling piston rotary compressor assembly according to  claim 1 , wherein the miniature rotary compressor is controlled by matching its speed to load demand.  
   
   
       12 . A miniature rolling piston rotary compressor assembly according to  claim 1 , wherein the motor stator and the rotor are separated by an air gap, and wherein said air gap acts as an oil separator.  
   
   
       13 . A miniature rolling piston rotary compressor assembly according to  claim 1 , further comprising a counterweight and a lightweight crescent shaped component, wherein said counterweight and said lightweight crescent shaped component form a contiguous hollow cylinder.  
   
   
       14 . A miniature rolling piston rotary compressor assembly according to  claim 1 , wherein the miniature rotary compressor is used for portable refrigeration applications, comprising personal cooling systems, small refrigerators and freezers, portable blood coolers, beverage coolers, or for small stationary applications, comprising cooling systems for microprocessors and other electronics components that generate substantial amounts of heat.  
   
   
       15 . A method for manufacturing a miniature rolling piston rotary compressor assembly, comprising the steps of: 
 a) machining parts of a compressor mechanism at a given set of tolerances,    b) incorporating a brushless DC motor, and    c) incorporating a casing,    wherein the miniature rotary compressor comprises a diameter of up to about 2.5 in., axial length of up to about 3.5 in., and a weight of up to about 1.7 pounds.    
   
   
       16 . A method for manufacturing a miniature rolling piston rotary compressor assembly according to  claim 15 , wherein the compressor mechanism comprises a cylinder, a shaft, roller, a vane, a top bearing flange and a bottom bearing flange with a drive motor, and a casing.  
   
   
       17 . A method for manufacturing a miniature rolling piston rotary compressor assembly according to  claim 16 , further comprising incorporating an oil sump, wherein the oil sump comprises oil at a level greater than half the cylinder height.  
   
   
       18 . A method for manufacturing a miniature rolling piston rotary compressor assembly according to  claim 15 , further comprising incorporating a discharge tube and a top cap, wherein the discharge tube is placed horizontally in the side of the top cap for reducing the axial length of the compressor assembly.  
   
   
       19 . A method for manufacturing a miniature rolling piston rotary compressor assembly according to  claim 15 , further comprising incorporating one or more electrical feedthrough pins and a top cap, wherein said one or more electrical feedthrough pins are incorporated via sealing with an insulating glass directly into said top cap.  
   
   
       20 . A method for manufacturing a miniature rolling piston rotary compressor assembly according to  claim 15 , wherein the miniature rotary compressor assembly comprises a vane and a cylinder, and wherein said vane and cylinder are assembled non-selectively.