To provide a sufficient cleaning effect by preventing the twist of a blade member from being easily returned by helically providing plural projected line parts around a rod, providing plural blade parts at a cylindrical part and inserting the rod into the central hole of the blade member pushed out and molded by a flexible material.

A rod 11 of a rotor 8 is composed of linear round steel or the like and at the mount part of a blade member 12, one or plural projected line parts 19 protruded onto the outer periphery of the rod 11 are helically provided around the rod 11. The blade member 12 integrally has plural blade parts 21 outside a cylindrical part 20 and is pushed out and molded by flexible rubber or plastic. Then, when the rod 11 is inserted into a hole 22 of the blade member 12, since the blade member 12 has flexibility, that cylindrical part 20 is twisted along the projected line parts 19 around the rod 11 and the blade member 12 is made helical. As a result, the blade member 12 is kept twisted by the projected line parts 19 around the rod 11.