To provide a structure of a thrust roller bearing assemblable only in the normal direction to a retaining part of a casing, and to assemble to the retaining part with large dimension in the axial direction.
In assembling, a folded vertical wall 6b formed on the outer circumferential edge of a lace 4b is internally fitted in a retaining part which is a circular recessed part. A plurality of extending pieces 17 are extended from the edge of this folded vertical wall 6b, and a projecting part 18 projected outward in the radial direction is formed on the tip part of each extending piece 17. When assembling in the opposite direction, this projecting part 18 interferes with the circumferential edge part of the retaining part to make the assembly impossible.
Nakai Shun
Kinzo Koyama
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