| 摘要 |
PROBLEM TO BE SOLVED: To secure the strength of a holder without increasing the thickness of elements by bonding both flat parts of a pair of elements having recessed parts at plural positions in the circumferential direction to each other with rivets, and specifying the outer diameter of the rivet in relation to the width of the flat part. SOLUTION: A pair of elements 9 are made to abut on each other at flat parts 10, and both the flat parts 10 are bonded to each other for fixation by rivets so as to form an annular holder 6 having pockets 8 at plural positions in the circumferential direction. A ratio of the outer diameter of the rivet 11 to the width of the flat part 10 in the diameter direction of the element 9 is regulated at 0.35-0.45. As a result of test, a ratio of the strength of the rivet 11 to the strength of the flat part 10 is regulated within a range at 0.85-1.25, and generation of a large difference between the strength of the rivet 11 and the strength of the flat part 10 is prevented, and the maximum strength of a bonding part is obtained in the limited condition. Strength of the holder can be sufficiently secured without increasing the thickness of the element, and reliability and durability can be improved. |
