PROBLEM TO BE SOLVED: To reliably prevent the entry of water into a one-way clutch.SOLUTION: In front of a one-way clutch 5, a first seal member 8 prevents the entry of water into the one-way clutch 5. In front of the first seal member 8, a second seal member 9 prevents the entry of water into the one-way clutch 5. The second seal member 9 includes an opposed surface 90 opposed to a cylindrical member 7 at a distance. The opposed surface 90 includes a first opposed surface 91 and a second opposed surface 92 that extend in mutually different directions.