| 摘要 |
PROBLEM TO BE SOLVED: To prevent abrasion due to sliding at a contact portion of an upper race and a bore plane of a rotor, and generation of abrasion of an inner diameter of the upper race and an outer diameter of a shaft.SOLUTION: A compression element driven by a stator 52 and a rotor 54, includes: a shaft 30 to which the rotor 54 is fastened; a cylinder block 20; a reciprocating piston 24; a main bearing 26 for journaling the shaft fixed to the cylinder block 20; and a thrust ball bearing 60 disposed between a horizontal face 58 of a lower hollow portion 56 of the rotor 54 and a thrust face 28 of the main bearing 26. The thrust ball bearing 60 includes: an upper race 66 and a lower race 68 respectively disposed at upper and lower portions of balls 62; and stop portions 84 fitted to each other, are disposed between the upper race 66 and a vertical face A of the lower hollow portion 56 of the rotor 54. The stop portions are composed of a projecting portion disposed on an outer peripheral portion of the upper race and a recessed portion disposed on the vertical face of the lower hollow portion of the rotor, and fitted to each other. |
