Scroll compressor

Abstract

To suppress reduced rotational moments that occur at a movable scroll. A scroll compressor ( 1 ) includes a fixed scroll ( 2 ), a movable scroll ( 3 ), and an anti-rotation mechanism ( 30 ). A spiral movable wrap ( 3 b ) of the movable scroll ( 3 ) meshes with a spiral fixed wrap ( 2 b ) of the fixed scroll ( 2 ). A first compression chamber (C 1 ) is formed by an inner wall surface ( 3 b 1 ) of the movable wrap ( 3 b ) and an outer wall surface ( 2 b 2 ) of the fixed wrap ( 2 b ). A second compression chamber (C 2 ) is formed by an inner wall surface ( 2 b 1 ) of the fixed wrap ( 2 b ) and an outer wall surface ( 3 b 2 ) of the movable wrap ( 3 b ). After a winding terminal end ( 3 f ) of the movable wrap ( 3 b ) contacts the outer wall surface ( 2 b 2 ) of the fixed wrap ( 2 b ) and the first compression chamber (C 1 ) is thereby closed, a winding terminal end ( 2 f ) of the fixed wrap ( 2 b ) contacts the outer wall surface ( 3 b 2 ) of the movable wrap ( 3 b ) and the second compression chamber (C 2 ) is thereby closed.

1 . A scroll compressor comprising:
 a fixed scroll including a fixed bottom plate having a discharge hole in a center of the fixed bottom plate and a spiral fixed wrap erected on the fixed bottom plate;   a movable scroll including a movable bottom plate and a spiral movable wrap that is erected on the movable bottom plate and is meshed with the fixed wrap;   a first compression chamber formed by an inner wall surface of the movable wrap and an outer wall surface of the fixed wrap;   a second compression chamber formed by an inner wall surface of the fixed wrap and an outer wall surface of the movable wrap; and   an anti-rotation mechanism that prevents rotation of the movable scroll, wherein   the scroll compressor is configured such that the movable scroll is caused to revolve around an axial center of the fixed scroll while the rotation of the movable scroll is prevented by the anti-rotation mechanism to change a volume of the first compression chamber and a volume of the second compression chamber and thereby cause a fluid in the first compression chamber and a fluid in the second compression chamber to be compressed separately and then discharged together through the discharge hole into a discharge chamber; and   an involute angle from a reference point on a base circle of the fixed wrap to a winding terminal end of the fixed wrap is less than an involute angle from a reference point on a base circle of the movable wrap to a winding terminal end of the movable wrap.   
     
     
         2 . The scroll compressor as claimed in  claim 1 , wherein
 after the winding terminal end of the movable wrap contacts the outer wall surface of the fixed wrap and the first compression chamber is thereby closed, the winding terminal end of the fixed wrap contacts the outer wall surface of the movable wrap and the second compression chamber is thereby closed.   
     
     
         3 . A scroll compressor comprising:
 a fixed scroll including a fixed bottom plate having a discharge hole in a center of the fixed bottom plate and a spiral fixed wrap erected on the fixed bottom plate;   a movable scroll including a movable bottom plate and a spiral movable wrap that is erected on the movable bottom plate and is meshed with the fixed wrap;   a first compression chamber formed by an inner wall surface of the movable wrap and an outer wall surface of the fixed wrap;   a second compression chamber formed by an inner wall surface of the fixed wrap and an outer wall surface of the movable wrap; and   an anti-rotation mechanism that prevents rotation of the movable scroll, wherein   the scroll compressor is configured such that the movable scroll is caused to revolve around an axial center of the fixed scroll while the rotation of the movable scroll is prevented by the anti-rotation mechanism to change a volume of the first compression chamber and a volume of the second compression chamber and thereby cause a fluid in the first compression chamber and a fluid in the second compression chamber to be compressed separately and then discharged together through the discharge hole into a discharge chamber; and   after a winding terminal end of the movable wrap contacts the outer wall surface of the fixed wrap and the first compression chamber is thereby closed, a winding terminal end of the fixed wrap contacts the outer wall surface of the movable wrap and the second compression chamber is thereby closed.   
     
     
         4 . The scroll compressor as claimed in  claim 1 , wherein
 the movable wrap includes a recess that is formed at a winding start end of the movable wrap and is indented from an inner wall surface of the winding start end.   
     
     
         5 . The scroll compressor as claimed in  claim 4 , further comprising:
 a third compression chamber that includes the discharge hole and is surrounded by the fixed wrap and the movable wrap, wherein   the second compression chamber communicates with the discharge hole after the first compression chamber communicates with the third compression chamber through the recess.   
     
     
         6 . The scroll compressor as claimed in  claim 1 , wherein
 the anti-rotation mechanism includes a ring that is press-fit into a circular hole formed in one of a back surface of the movable bottom plate and a housing wall facing the back surface, and a pin that protrudes from another one of the back surface and the housing wall and is loosely fit in an inside of the ring.   
     
     
         7 . The scroll compressor as claimed in  claim 1 , wherein
 a center of the fixed bottom plate is shifted from a center of the base circle of the fixed wrap; and   a center of the movable bottom plate is shifted from a center of the base circle of the movable wrap.