Scroll compressor

Abstract

A scroll compressor is provided. The scroll compressor may include a back pressure chamber formed between a wrap portion and a base portion of an orbiting scroll. A center of the back pressure chamber may be eccentric from a geometric center of the orbiting scroll along a line where a gas repulsive force is applied. Such a configuration may reduce/eliminate unstable behavior of the orbiting scroll, and frictional loss or abrasion between the orbiting scroll and various peripheral components may be reduced. This may enhance reliability and performance of the scroll compressor.

What is claimed is: 
     
         1 . A scroll compressor, comprising:
 a case;   a fixed scroll and an orbiting scroll installed in the case, the orbiting scroll comprising:
 a wrap portion engaged with a fixed wrap of the fixed scroll and forming compression chambers therebetween; and 
 a base portion coupled to the wrap portion and configured to be movable towards the fixed scroll to support the wrap portion; 
   a driving motor coupled to the base portion, at a side of the base portion opposite a side thereof to which the wrap portion is coupled, and configured to eccentrically rotate the base portion and the wrap portion;   a main frame installed in the case and configured to axially support the base portion; and   a back pressure chamber formed between the wrap portion and the base portion, and in communication with the compression chambers, wherein a geometric center of the back pressure chamber is eccentric from a geometric center of the wrap portion.   
     
     
         2 . The scroll compressor of  claim 1 , wherein a first virtual line connects a geometric center of the wrap portion with a rotation center of the driving motor to which the base portion is coupled, and the geometric center of the back pressure chamber is within a range of ±30° with respect to a second virtual line that is perpendicular to the first virtual line. 
     
     
         3 . The scroll compressor of  claim 1 , further comprising a ring shaped seal installed between the wrap portion and the base portion, wherein the back pressure chamber is formed within a periphery of the seal. 
     
     
         4 . The scroll compressor of  claim 1 , wherein the base portion includes:
 a boss coupled to a rotation shaft of the driving motor; and   a base flange extending radially outward from the boss and facing the wrap portion, wherein the back pressure chamber is formed on a side surface of the base flange facing the wrap portion.   
     
     
         5 . The scroll compressor of  claim 1 , wherein the wrap portion includes:
 a wrap flange facing the base portion;   an orbiting wrap extending from the wrap flange and engaged with the fixed wrap of the fixed scroll; and   a back pressure hole extending through the wrap flange to provide for communication between the back pressure chamber and the compression chambers.   
     
     
         6 . The scroll compressor of  claim 5 , wherein the back pressure hole is formed at a position where a discharge pressure and an intermediate pressure, which is between the discharge pressure and a suction pressure, are applied to the back pressure chamber. 
     
     
         7 . The scroll compressor of  claim 6 , wherein the back pressure hole is formed at a point on the orbiting wrap that is greater than a discharge starting angle of the orbiting wrap and less than the discharge starting angle plus 180 degrees. 
     
     
         8 . The scroll compressor of  claim 1 , further comprising a plurality of keys integrally formed at one of the wrap portion or the base portion, and a corresponding plurality of key grooves formed in the other of the wrap portion of the key portion and respectively coupled with the plurality of keys. 
     
     
         9 . The scroll compressor of  claim 1 , wherein the case is divided into first and second spaces having first and second pressures, respectively, the first pressure being less than the second pressure, and wherein the wrap portion and the base portion are installed in the first space. 
     
     
         10 . A scroll compressor, comprising:
 a fixed scroll having a fixed wrap; and   an orbiting scroll having an orbiting wrap and performing an orbiting motion with respect to the fixed scroll;   a pair of compression chambers formed between the orbiting scroll and the fixed scroll, wherein the pair of compression chambers consecutively move as the orbiting scroll orbits with respect to the fixed scroll,   wherein the orbiting scroll is divided into a plurality of parts in an axial direction, and wherein a back pressure chamber is formed between two adjacent parts of the plurality of parts to provide for communication between the pair of compression chambers and the back pressure chamber, and wherein a geometric center of the back pressure chamber is eccentric from a geometric center of the wrap portion.   
     
     
         11 . The scroll compressor of  claim 10 , wherein a first virtual line connects a geometric center of the orbiting scroll with a rotation center of a crank shaft about which the orbiting scroll performs an orbit motion, and the geometric center of the back pressure chamber is within a range of ±30° with respect to a second virtual line that is perpendicular to the first virtual line. 
     
     
         12 . The scroll compressor of  claim 10 , further comprising a ring shaped seal installed between the two adjacent parts of the plurality of parts of the orbiting wrap, wherein the back pressure chamber is formed within a periphery of the seal. 
     
     
         13 . The scroll compressor of  claim 12 , further comprising a back pressure hole extending through one of the plurality of parts of the orbiting wrap to provide for communication between the pair of compression chambers and the back pressure chamber, at a position corresponding to the pair of compression chambers. 
     
     
         14 . The scroll compressor of  claim 13 , wherein the back pressure hole is formed at a position where a discharge pressure and an intermediate pressure, which is between the discharge pressure and a suction pressure, are applied to the back pressure chamber. 
     
     
         15 . The scroll compressor of  claim 14 , wherein the back pressure hole is formed at a point on the orbiting wrap that is greater than a discharge starting angle of the orbiting wrap and less than the discharge starting angle plus 180 degrees.