Scroll compressor

Abstract

A scroll compressor includes a rotation shaft, a fixed scroll, a movable scroll, a compression chamber, a shaft support, a housing, a movable member arranged in the shaft support, and a rotation restriction mechanism configured to restrict rotation of the movable scroll. The rotation restriction mechanism includes pins, recesses into which the respective pins are loosely fitted, and the movable member. The movable member includes the pins or the recesses. A switching mechanism is configured to switch the movable member between a state in which movement of the movable member in a radial direction of the rotation shaft is restricted and a state in which the restriction is canceled and the movable member can move freely, which changes a movable range of the movable member in the radial direction so that an orbital radius of the movable scroll is changed.

1 . A scroll compressor comprising:
 a rotation shaft;   a fixed scroll including a fixed spiral wall;   a movable scroll including a movable spiral wall engaged with the fixed spiral wall, wherein the movable scroll orbits when the rotation shaft is rotated;   a compression chamber defined between the fixed spiral wall and the movable spiral wall, wherein the compression chamber has a volume that is decreased when the movable scroll orbits, and refrigerant is compressed in the compression chamber when the volume is decreased;   a shaft support that supports the rotation shaft, wherein the shaft support and the fixed scroll are arranged at opposite sides of the movable scroll;   a housing that accommodates the rotation shaft, the fixed scroll, the movable scroll, and the shaft support;   a movable member arranged in the shaft support;   a rotation restriction mechanism configured to restrict rotation of the movable scroll, wherein the rotation restriction mechanism includes a plurality of pins, a plurality of recesses into which the respective pins are loosely fitted, and the movable member, and wherein the movable member includes one of the plurality of pins and the plurality of recesses; and   a switching mechanism configured to switch the movable member between a state in which movement of the movable member in a radial direction of the rotation shaft is restricted and a state in which the restriction is canceled and the movable member can move freely, which changes a movable range of the movable member in the radial direction of the rotation shaft so that an orbital radius of the movable scroll is changed.   
     
     
         2 . The scroll compressor according to  claim 1 , wherein
 the switching mechanism includes a valve chamber, which is arranged in the shaft support, and a valve body, which is accommodated in the valve chamber, and   the valve body presses the movable member toward the movable scroll.   
     
     
         3 . The scroll compressor according to  claim 2 , wherein
 the valve chamber includes a primary void and a secondary void,   the primary void is located between the secondary void and the movable scroll, and   the switching mechanism includes a switching valve configured to switch between a state in which the secondary void is in communication with a low pressure region, the pressure of which is lower than that of the primary void, and a state in which the secondary void is in communication with a high pressure region, the pressure of which is higher than that of the primary void.   
     
     
         4 . The scroll compressor according to  claim 3 , further comprising a back pressure region located between the movable scroll and the movable member and configured to apply force to the movable scroll so that the movable scroll is pressed toward the fixed scroll, wherein
 the movable member includes a communication passage that communicates the back pressure region and the primary void.   
     
     
         5 . The scroll compressor according to  claim 3 , wherein
 the valve chamber is one of a plurality of valve chambers that are arranged in the shaft support in intervals in a circumferential direction of the rotation shaft, and   the switching mechanism includes a passage that extends in the shaft support from the switching valve to the valve chambers.   
     
     
         6 . The scroll compressor according to  claim 2 , wherein the movable member includes a fitting recess to which the valve body can be fitted. 
     
     
         7 . The scroll compressor according to  claim 2 , further comprising a seat member fixed to the housing and arranged between the movable scroll and the movable member,
 wherein the seat member receives the movable member that is pressed toward the movable scroll by the valve body.   
     
     
         8 . The scroll compressor according to  claim 1 , wherein
 the switching mechanism includes
 a primary void and a secondary void arranged in the shaft support, wherein the primary void is located between the movable scroll and the secondary void, 
 a conical recess arranged in the shaft support, 
 a conical projection that is arranged in the movable member and movable toward and away from the conical recess, and 
 a switching valve that switches between a state in which the secondary void is in communication with a low pressure region, the pressure of which is lower than that of the primary void, and a state in which the secondary void is in communication with a high pressure region, the pressure of which is higher than that of the primary void.