Scroll compressor and refrigeration cycle apparatus using the same

Abstract

A scroll compressor includes a fixed scroll and an orbiting scroll and causes the orbiting scroll to perform an orbiting motion to form a suction chamber and a compression chamber. The scroll compressor includes a first space in a back surface center of the orbiting scroll, lubricant in a bottom of a sealed container, a second space provided further on an outer circumference side than the first space on a back surface of the orbiting scroll, a first oil leak path for causing a part of oil in the first space to leak to the second space, an oil return passage for returning most of the oil in the first space to the bottom in the sealed container, a second oil leak path for causing a part of the oil in the second space to leak to the suction chamber, and a third oil leak path.

1 . A scroll compressor including a fixed scroll in which a spiral wrap is erected on a base plate and an orbiting scroll including a spiral wrap erected on a mirror plate and meshed with the fixed scroll to perform an orbiting motion, the scroll compressor causing the orbiting scroll to perform the orbiting motion with respect to the fixed scroll to thereby form a suction chamber and a compression chamber,
 the scroll compressor comprising:
 a first space formed in a back surface center of the orbiting scroll, lubricant stored in a bottom of a sealed container being led to the first space, and the first space having pressure close to discharge pressure; 
   a second space provided further on an outer circumference side than the first space on a back surface of the orbiting scroll, the second space having pressure between the discharge pressure and suction pressure;
 a first oil leak path for causing a part of oil in the first space to leak to the second space; 
 an oil return passage for returning most of the oil in the first space to the bottom in the sealed container; 
 a second oil leak path for causing a part of the oil in the second space to leak to the suction chamber; and 
 a third oil leak path for allowing the oil in the second space to escape to the compression chamber to adjust the pressure in the second space according to a difference between pressure in the compression chamber and the pressure in the second space. 
   
     
     
         2 . The scroll compressor according to  claim 1 , wherein the third oil leak path is provided in the fixed scroll, includes a backpressure valve that opens and closes according to the difference between the pressure in the compression chamber and the pressure in the second space, and allows the oil in the second space to escape to the compression chamber to adjust the pressure in the second space. 
     
     
         3 . The scroll compressor according to  claim 2 , wherein the third oil leak path includes a backpressure valve inflow path for causing the second space and the backpressure valve to communicate and a backpressure valve outflow path for causing the compression chamber and the backpressure valve to communicate, and the backpressure valve outflow path is caused to communicate with the compression chamber after completion of a suction process and start of compression. 
     
     
         4 . The scroll compressor according to  claim 1 , wherein the third oil leak path is provided in the orbiting scroll, configured by a backpressure hole for allowing fluid in the second space to escape to the compression chamber according to the difference between the pressure in the compression chamber and the pressure in the second space, and allows the fluid in the second space to escape to the compression chamber to adjust the pressure in the second space. 
     
     
         5 . The scroll compressor according to  claim 4 , wherein the backpressure hole is configured to cause the compression chamber after completion of a suction process and start of compression and the second space to communicate. 
     
     
         6 . The scroll compressor according to  claim 1 , wherein the third oil leak path is opened in a position that communicates with both of an orbiting-outer-line-side compression chamber and an orbiting-inner-line-side compression chamber. 
     
     
         7 . The scroll compressor according to  claim 1 , wherein a orbiting boss section for coupling to a rotating shaft is provided on a back surface side of the orbiting scroll, at least a part of the first space is formed in the orbiting boss section, and the first oil leak path for causing necessary minimum oil to leak from the first space to the second space is formed on an end face side of the orbiting boss section. 
     
     
         8 . The scroll compressor according to  claim 7 , wherein
 the second space is formed by the fixed scroll, a frame to which the fixed scroll is attached, and the orbiting scroll, and the first space of the orbiting boss section and the second space is partitioned by a seal member provided on the orbiting boss section end face side, and   the first oil leak path is configured by the seal member provided on the orbiting boss section end face side and a groove formed to intermittently supply the oil in the first space to the second space via the seal member according to an orbiting motion of the orbiting scroll.   
     
     
         9 . The scroll compressor according to  claim 8 , wherein the groove configuring the first oil leak path is configured by a slit or one or more holes formed in the orbiting boss section end face. 
     
     
         10 . The scroll compressor according to  claim 1 , wherein the second oil leak path is a groove provided on a mirror plate surface of the orbiting scroll, the groove causing the second space and the suction chamber to intermittently communicate according to the orbiting motion of the orbiting scroll. 
     
     
         11 . The scroll compressor according to  claim 1 , wherein a refrigerant having an adiabatic exponent larger than 1.09 is working fluid. 
     
     
         12 . A refrigeration cycle apparatus for refrigeration and air conditioning configured using the scroll compressor according to  claim 1 .