Patent ID: 7255635

Claim:
A polishing apparatus, comprising: an upper polishing plate for polishing a workpiece; a lower polishing plate for polishing the workpiece; an outer pin gear having an inner gear section; an inner pin gear having an outer gear section; and a carrier holding the workpiece, said carrier having outer gear teeth, which are engaged with the inner gear section of said outer pin gear and the outer gear section of said inner pin gear so as to rotate said carrier on its axis and move said carrier around said inner pin gear, wherein at least one of the inner gear section and the outer gear section includes a plurality of gear teeth, which are arranged at regular intervals and each of which comprises: a pin ring; each of the gear teeth being composed of a pin proper that is fixed to the pin ring and extended upward therefrom; and a cylindrical collar having a closed top end and an opened bottom end rotatably covering and fitting the pin proper at a fitting section, wherein the top of the collar and the cylindrical sidewall of the collar are formed on one piece, to prevent fluids from entering between the collar and the pin proper.