Scroll member, method of manufacturing same, compression mechanism and scroll compressor

Abstract

A scroll member for a compression mechanism installed in a scroll compressor is manufactured by a method including a casting step and a cutting step. An iron casting is formed in the casting step, which includes a spiraling part. The iron casting obtained in the casting step is cut during the cutting step in order to obtain a final shape of the scroll member. The iron casting may include a fixed part having a central portion with a first axial thickness and an external periphery portion with a second axial thickness larger than the first axial thickness before the cutting step. A dimension of a specified portion of the spiraling part may be larger before the cutting step is performed than after the cutting step is performed, with the specified portion preferably disposed toward an external periphery of the spiraling part.

What is claimed is: 
     
         1 . A scroll member for a compression mechanism installed in a compressor, the scroll member comprising:
 a fixed part; and   a spiraling part extending axially from a side of the fixed part in a spiraling formation,   the scroll member being manufactured by a method including
 a casting step including forming an iron casting including the fixed part and the spiraling part, and 
 a cutting step including cutting the iron casting obtained in the casting step in order to obtain a final shape of the scroll member, 
 the fixed part of the iron casting obtained in the casting step including a central portion with a first axial thickness and an external periphery portion with a second axial thickness larger than the first axial thickness, the central portion being radially closer to a center of the spiraling part than the external periphery portion, and 
   a ratio of height to thickness of the spiraling part being at least 8.5 after the cutting step, the height being measured from the fixed part.   
     
     
         2 . A compression mechanism including at least one scroll member according to  claim 1  used as an orbiting scroll, a fixed scroll, or both. 
     
     
         3 . A scroll compressor including the compression mechanism according to  claim 2 . 
     
     
         4 . The scroll compressor according to  claim 3 , wherein
 a refrigerant including carbon dioxide as a main component is used therein.   
     
     
         5 . A scroll member for a compression mechanism installed in a compressor, the scroll member comprising:
 a spiraling part extending in a spiraling formation,   the scroll member being manufactured by a method including
 a casting step including forming an iron casting including the spiraling part, and 
 a cutting step including cutting the iron casting obtained in the casting step in order to obtain a final shape of the scroll member, 
 a dimension of a specified portion of the spiraling part being larger before the cutting step is performed than after the cutting step is performed, and 
 the specified portion of the spiraling part extending along the spiraling formation from an end on an external periphery to a position different from an end at a center of the spiraling formation, and 
   a ratio of height to thickness of the spiraling part being at least 8.5 after the cutting step, the height being measured along an extending direction of the spiraling part.   
     
     
         6 . A compression mechanism including at least one scroll member according to  claim 5  used as an orbiting scroll, a fixed scroll, or both. 
     
     
         7 . A scroll compressor including the compression mechanism according to  claim 6 . 
     
     
         8 . The scroll compressor according to  claim 7 , wherein
 a refrigerant including carbon dioxide as a main component is used therein.