Patent ID: 7022001

Claim:
A polishing apparatus, comprising: an upper polishing plate; a lower polishing plate rotating in a prescribed direction; a sun gear rotating in a prescribed direction; an internal gear enclosing said sun gear and rotating in a prescribed direction; a first rotary holding member rotatably holding said lower polishing plate; a second rotary holding member rotatably holding said sun gear or said internal gear; a carrier being provided between said upper polishing plate and said lower polishing plate and engaged with said sun gear and said internal gear, said carrier holding a work piece so as to simultaneously polish both side faces of the work piece with polishing faces of said upper polishing plate and said lower polishing plate; and direct drive motors for respectively rotating said lower polishing plate, said sun gear and said internal gear, each of said direct drive motors having a fixed cylindrical member, which is located at a central part and whose one end face is opened, and a ring-shaped output member, which outputs torque and which is provided on the one end face side, wherein said direct drive motors include: a first direct drive motor having the ring-shaped output member, whose diameter is larger than an inner diameter of the cylindrical member, which rotates along a circumferential edge of the cylindrical member and which is directly connected to one of said rotary holding members; and a second direct drive motor being provided under said first direct drive motor, and one end of a rotary shaft, which is pierced through the cylindrical member of said first direct drive motor, is connected to the other rotary holding member, and the other end of the rotary shaft is directly connected to the ring-shaped output member of said second direct drive motor.