| 摘要 |
PURPOSE:To prolong the service life of each race by spreading the rolling region of a ball element by means of a movable scroll side race and a fixed race installed in shiftable manners within prescribed regions in the radial direction and peripheral direction, respectively. CONSTITUTION:A movable scroll side race 214 has each projection part projecting in the inside diameter direction at two positions symmetrical for the center, and further a recessed part for freely fitting the projection part is formed in the groove 217 of a side plate 211 which receives the movable scroll side race 214. The movable scroll side race 214 can be shifted freely within a certain restricted region for the side plate 211 by making the recessed part sufficiently larger than the projection part and making the width of the groove 217 larger than the width of the movable scroll side race 214. On the other hand, a shiftable structure of a fixed lace 221 similar to that of the movable scroll side race 214 is realized by forming a projection part which projects in the outside diameter direction on the outside diameter side and forming a recessed part for the free insertion of the projection part, in a groove 113 which is formed on the inner wall of a front end plate and receives the fixed scroll 221. |
