US Patent 7255635 Polishing apparatus

In polishing apparatus of the present invention, collars can be easily exchange. The polishing apparatus comprises: an outer pin gear having an inner gear section; an inner pin gear having an outer gear section; and a carrier having outer gear teeth, which are engaged with the inner gear section of the outer pin gear and the outer gear section of the inner pin gear so as to rotate and move the carrier around the inner pin gear. At least one of the inner gear section and the outer gear section includes gear teeth, each of which comprises: a pin proper being fixed to a pin ring and extended upward therefrom; a cylindrical collar rotatably covering and fitting the pin proper at a fitting section.