PURPOSE: To eliminate overlapping of half washers by providing the first engaging part on a ring shaped washer and the second engaging part engaged with the first engaging part through concaves and convexes.

CONSTITUTION: A half washer 13 is incorporated at the outer circumferential position of a groove 10a of a connecting part 10, and engaging parts 14a and 14b of the half washer 13 are engaged with engaging parts 12a and 12b of a flat washer 11. A clutch cover 15 is inserted from the outer circumferential part of a pinion gear 9. Each of the washers 11 and 13 is supported by a clutch outer 2 through the engaging parts 12a, 12b, 14a and 14b of the washers 11 and 13. In this way, overlapping of the half washers is surely installed by the clutch cover.