Motor operated compressor

Abstract

A motor operated compressor may include a first scroll; a second scroll that forms a pair of two compression chambers between the first scroll and the second scroll while being engaged with the first scroll to perform an orbiting movement; a frame fixed in a radial direction at a side of the first scroll with the second scroll interposed between the first scroll and the frame; and a balance weight fixedly coupled to the rotation shaft, wherein the rotation shaft or the balance weight is supported on the frame in an axial direction.

What is claimed is: 
     
         1 . A motor operated compressor, comprising:
 a first scroll;   a second scroll that forms a pair of two compression chambers between the first scroll and the second scroll while being engaged with the first scroll to perform an orbiting movement;   a frame fixed in a radial direction on a side of the first scroll with the second scroll interposed between the frame and the first scroll;   a rotation shaft eccentrically coupled to the second scroll through the frame; and   a first bearing protrusion portion protruding in a radial direction from one of the rotation shaft or a balance weight fixedly coupled to the rotation shaft so as to support the rotation shaft by the frame in an axial direction.   
     
     
         2 . The motor operated compressor of  claim 1 , wherein the first bearing protrusion portion is formed between the second scroll and the frame. 
     
     
         3 . The motor operated compressor of  claim 1 , wherein a shaft hole is formed in the frame, and
 the rotation shaft is disposed to pass through the shaft hole, and is supported in a radial direction by a circumference of the shaft hole, and   a second bearing protrusion portion is protruded in an axial direction from the circumference of the shaft hole toward the first bearing protrusion portion to correspond to the first bearing protrusion portion.   
     
     
         4 . The motor operated compressor of  claim 3 , wherein the balance weight comprises:
 an annular fixed portion configured to surround the rotation shaft and be fixed to the rotation shaft; and   an eccentric mass portion having a circular-arc cross section protruded in an axial direction from part of an edge of the fixed portion to be spaced apart from the rotation shaft, and   wherein the first bearing protrusion portion is supported by the second bearing protrusion portion in a region surrounded by the eccentric mass portion.   
     
     
         5 . The motor operated compressor of  claim 4 , wherein an outer diameter of the first bearing protrusion portion is equal to or greater than that of the second bearing protrusion portion. 
     
     
         6 . The motor operated compressor of  claim 4 , wherein the second bearing protrusion portion, the first bearing protrusion portion, and the balance weight are sequentially disposed in an axial direction. 
     
     
         7 . The motor operated compressor of  claim 4 , wherein the first bearing protrusion portion is protruded in a radial direction from the balance weight, and
 a support portion is protruded from an outer circumferential surface of the rotation shaft to engage with the fixed portion so as to prevent an axial movement of the balance weight.   
     
     
         8 . The motor operated compressor of  claim 1 , wherein a first end portion of the rotation shaft is rotatably coupled to the first scroll through the frame and the second scroll. 
     
     
         9 . The motor operated compressor of  claim 8 , wherein the first end portion of the rotation shaft is supported on the frame and the first scroll, respectively, in an axial direction to form a fixed end, and a second end portion of the rotation shaft, which is opposite to the first end portion with respect to the frame, forms a free end. 
     
     
         10 . The motor operated compressor of  claim 9 , wherein the rotation shaft is formed with an oil supply groove from an end of the first end portion to a predetermined length in an axial direction, and
 a plurality of oil supply holes are formed at intervals along an axial direction to face the first scroll, the second scroll, and the frame in the middle of the oil supply groove.   
     
     
         11 . The motor operated compressor of  claim 10 , wherein a pressure-reducing member is inserted into the oil supply groove, the pressure reducing member being configured to decrease an inner diameter of the oil supply groove so as to reduce the pressure of oil passing through the oil supply groove. 
     
     
         12 . The motor operated compressor of  claim 10 , wherein the motor operated compressor further comprises a rear housing formed to cover the first scroll, and
 a discharge space is formed between the first scroll and the rear housing to accommodate refrigerant and oil discharged from the compression chamber, and   an oil supply passage configured to communicate an oil storage portion of the discharge space with the oil supply groove is formed in the first scroll to supply oil filled in the oil storage portion of the discharge space to the oil supply groove by a pressure difference.   
     
     
         13 . The motor operated compressor of  claim 12 , wherein a back pressure space is formed between the second scroll and the frame, and
 the back pressure space communicates with at least one oil supply hole of the plurality of oil supply holes to receive oil through the oil supply groove and the at least one oil supply hole.   
     
     
         14 . The motor operated compressor of  claim 1 , wherein a shaft hole is formed in the frame, and
 a first bearing formed to surround the rotation shaft is provided on an inner circumferential surface of the shaft hole, and   a first bearing portion of the rotation shaft is disposed to pass through the shaft hole, and is supported by the first bearing in a radial direction.   
     
     
         15 . The motor operated compressor of  claim 14 , wherein the rotation shaft is provided with a second bearing portion at a first end thereof, and
 the first scroll is provided with a bearing receiving portion formed to accommodate the second bearing portion, and   a second bearing formed to surround the second bearing portion is provided between an inner circumferential surface of the bearing receiving portion and an outer circumferential surface of the second bearing portion.   
     
     
         16 . The motor operated compressor of  claim 15 , wherein the rotation shaft is provided with a cylindrically shaped eccentric portion inserted into a rotation shaft coupling portion of the second scroll, and
 the eccentric portion has a shaft center at an eccentric position from a central axis of the rotation shaft such that the rotation shaft is coupled to the second scroll at an eccentric position, and   a third bearing formed to surround the eccentric portion is provided between an inner circumferential surface of the rotation shaft coupling portion and an outer circumferential surface of the eccentric portion.   
     
     
         17 . The motor operated compressor of  claim 16 , wherein the first bearing, the second bearing, and the third bearing are configured with bush bearings. 
     
     
         18 . The motor operated compressor of  claim 16 , wherein the rotation shaft is formed with an oil supply groove from an end of the first end portion to a predetermined length in an axial direction, and
 a plurality of oil supply holes are formed at intervals along an axial direction of the rotation shaft to face the first bearing, the second bearing, and the third bearing from the middle of the oil supply groove.