Electrically driven compressors and methods for circulating lubrication oil through the same

Abstract

An oil storage area ( 45 a ) is defined on the bottom of a motor chamber ( 45 ) of a scroll compressor ( 1 ). An oil transfer route ( 4 a ) is defined in the portion of a center housing ( 4 ) that corresponds to the storage area ( 45 a ). Lubricating oil L is separated from the discharged, compressed refrigerant by an oil separator ( 80 ) and the lubricating oil L is supplied to the rear side of a movable scroll ( 20 ) due to a pressure differential within the compressor ( 1 ). After lubricating slide contact portions of scroll walls ( 28, 30 ) of the fixed and movable scrolls ( 2, 20 ), the lubricating oil L is temporarily stored in the storage area ( 45 a ) and then is transferred due to a refrigerant pressure differential to the suction-side of a compression mechanism ( 21 ) via the oil transfer route ( 4 a ). The lubricating oil L is then transferred to the oil separator ( 80 ) together with the compressed refrigerant that is discharged from a compression chamber ( 32 ) of the compression mechanism ( 21 ). Thus, the lubricating oil L contained in the discharged, compressed refrigerant can be effectively separated from the compressed refrigerant and circulated to and from the rear side of the movable scroll ( 20 ) in order to lubricate moving parts within the compressor ( 1 ) using the refrigerant pressure differentials within the compressor ( 1 ).

1 . A scroll compressor comprising: 
 a fixed scroll and a movable scroll having respective scroll walls, the scroll walls slidably contacting each other and defining a compression chamber between the fixed scroll and the movable scroll,    an electric motor rotatably driving the movable scroll, whereby a refrigerant is drawn from a suction-side region, is compressed within the compression chamber and is then discharged to a discharge-side region as the movable scroll rotates relative to the fixed scroll, wherein a refrigerant flow channel is defined from the suction side region to the discharge side region via the compression chamber,    a motor housing defining a substantially sealed motor chamber, wherein the electric motor is disposed within the motor chamber,    a communication path linking the refrigerant flow channel to the motor chamber and    a lubricating oil supply route defined between a discharge-side region of the refrigerant flow channel and an area proximal to slide contact portions of the scroll walls of the fixed and movable scrolls, the lubricating oil supply route being arranged and constructed so that a difference between the pressure at the discharge-side region of the refrigerant flow channel and the pressure at the area proximal to the slide contact portions of the scroll walls of the fixed and movable scrolls urges lubricating oil towards the slide contact portions of the scroll walls of the fixed and movable scrolls via the lubricating oil supply route.    
     
     
         2 . A scroll compressor as in  claim 1 , wherein the lubricating oil supply route includes a first oil supply route and a second oil supply route, the first oil supply route supplying the lubricating oil to a front side of the movable scroll, and the second oil supply route communicating with the front side of the movable scroll and extending to the slide contact portions.  
     
     
         3 . A method for circulating lubricating oil through an electric compressor having a fixed scroll and a movable scroll with respective scroll walls that slidably contact with each other and define a compression chamber between the fixed scroll and the movable scroll, wherein a refrigerant flow channel is defined between a suction-side region and a discharge-side region, and a lubricating oil supply route is defined between the discharge-side region of the refrigerant flow channel and the area proximal to slide contact portions of the scroll walls of the fixed and movable scrolls, comprising: 
 pressure-feeding lubricating oil to the slide contact portions of the scroll walls of the fixed and movable scrolls via the lubricating oil supply route based upon a difference between the pressure at the discharge-side region of the refrigerant flow channel and the pressure at the area proximal to the slide contact portions of the scroll walls of the fixed and movable scrolls.    
     
     
         4 . A method as in  claim 3 , wherein the lubricating oil supply route includes a first oil supply route and a second oil supply route, the method further comprising supplying lubricating oil via the first oil supply route to a front side of the movable scroll, and supplying lubricating oil via the second oil supply route to the slide contact portions of the scroll walls of the fixed and movable scrolls.  
     
     
         5 . A scroll compressor comprising: 
 a compressor having a fixed scroll and a movable scroll, the movable scroll coupled to a drive shaft, wherein a discharge-side region is disposed in communication with the fixed scroll,    an electric motor rotatably driving the drive shaft, and    a lubricating oil route arranged and constructed to transfer lubrication oil from the discharge-side region to slide contact portions of the fixed and movable scrolls via the lubricating oil supply route so as to lubricate the slide contact portions as the refrigerant is compressed by the compressor.    
     
     
         6 . A scroll compressor as in  claim 5 , wherein the lubricating oil route has a first end and a second end that respectively communicate with the discharge-side region and a suction-side region of the compressor, wherein the lubricating oil route is arranged and constructed so that the lubrication oil flows from the discharge-side region to the slide contact portions of the fixed and movable scrolls due to a difference in pressure between refrigerant pressure at the discharge-side region and refrigerant pressure at an area proximal to the slide contact portions of the fixed and movable scrolls.  
     
     
         7 . A scroll compressor as in  claim 6 , further including an oil separator communicating with the discharge-side region, the oil separator being arranged and constructed to separate the lubricating oil from compressed refrigerant that has been discharged from the compression chamber.  
     
     
         8 . A method for circulating lubricating oil within an electrically driven scroll compressor driven by an electric motor, the method comprising: 
 generating a pressure differential between a discharge-side region of the compressor and slide contact portions of the compressor, thereby causing lubricating oil to move via a lubricating oil route from the discharge-side region to the slide contact portions.    
     
     
         9 . A method as in  claim 8 , wherein the pressure differential along the lubricating oil route is generated due to refrigerant that is compressed by the compressor.  
     
     
         10 . A method as in  claim 9 , wherein a first end of the lubricating oil route communicates with the discharge-side region and a second end of the lubricating oil route communicates with a suction port, the method further comprising forcing the lubrication oil from the discharge-side region to the area proximal to the slide contact portions due to a difference in refrigerant pressure between the discharge-side region and the area proximal to the slide contact portions.  
     
     
         11 . An method as in  claim 10 , further comprising pressure-feeding the lubricating oil via a lubricating oil transfer route defined between the area proximal to the slide contact portions and the suction-side region of the compressor due to a difference between the refrigerant pressure at the area proximal to the slide contact portions and the suction-side region of the compressor.  
     
     
         12 . A method as in  claim 11 , further including separating the lubricating oil from compressed refrigerant that has been discharged from a compression chamber of the compressor.  
     
     
         13 . A method as in  claim 12 , further including storing the lubricating oil that lubricated the slide contact portions before the stored lubricating oil is transferred to the suction-side region.  
     
     
         14 . A method for circulating lubricating oil within an electrically driven scroll compressor, comprising: 
 separating lubricating oil from compressed refrigerant in an area proximal to and communicating with a discharge port of the compressor, and    transferring the separated lubricating oil to slide contact portions of scroll walls of fixed and movable scrolls via a lubricating oil supply route using a refrigerant pressure-differential between the area proximal to and communicating with the discharge port and an area proximal to the slide contact portions of the scroll walls of the fixed and movable scrolls, wherein the slide contact portions are lubricated with the lubricating oil .    
     
     
         15 . An electrically driven scroll compressor, comprising: 
 means for separating lubricating oil from compressed refrigerant in an area proximal to and communicating with a discharge port of the compressor, and    means for transferring the separated lubricating oil to slide contact portions of scroll walls of fixed and movable scrolls using a refrigerant pressure-differential between the area proximal to and communicating with the discharge port and an area proximal to the slide contact portions of the scroll walls of the fixed and movable scrolls, whereby the slide contact portions are lubricated with the lubricating oil.