Grinding apparatus and grinding method

Abstract

There is provided a grinding apparatus including: an upper surface plate; a lower surface plate disposed facing the upper surface plate and rotating in an opposite direction to the upper surface plate; a sun gear rotated by a same rotational shaft as the upper surface plate and the lower surface plate; an internal gear rotated by the same rotational shaft as the upper surface plate and the lower surface plate; and a planetary carrier in which a holding hole that holds a workpiece is formed and which revolves while rotating in engagement with the sun gear and the internal gear. The holding hole in the planetary carrier is provided with a cutaway in a side of the holding hole that contacts a side surface of the workpiece when the planetary carrier rotates.

What is claimed is: 
     
         1 . A grinding apparatus comprising:
 an upper surface plate;   a lower surface plate disposed facing the upper surface plate and rotating in an opposite direction to the upper surface plate;   a sun gear rotated by a same rotational shaft as the upper surface plate and the lower surface plate;   an internal gear rotated by the same rotational shaft as the upper surface plate and the lower surface plate; and   a planetary carrier in which a holding hole that holds a workpiece is formed and which revolves while rotating in engagement with the sun gear and the internal gear,   wherein the holding hole in the planetary carrier is provided with a cutaway in a side of the holding hole that contacts a side surface of the workpiece when the planetary carrier rotates.   
     
     
         2 . The grinding apparatus according to  claim 1 ,
 wherein the holding hole is substantially rectangular and the cutaway is provided in an edge on the side of the holding hole that contacts the side surface of the workpiece when the planetary carrier rotates.   
     
     
         3 . The grinding apparatus according to  claim 2 ,
 wherein the cutaway is provided in the edge on the side of the substantially rectangular holding hole that contacts the side surface of the workpiece and also in another edge that faces the edge.   
     
     
         4 . The grinding apparatus according to  claim 3 ,
 wherein the edge on the side of the holding hole that contacts the side surface of the workpiece when the planetary carrier rotates corresponds to a length direction of a rectangle.   
     
     
         5 . A grinding method for a grinding apparatus which includes: an upper surface plate; a lower surface plate disposed facing the upper surface plate and rotating in an opposite direction to the upper surface plate; a sun gear rotated by a same rotational shaft as the upper surface plate and the lower surface plate; an internal gear rotated by the same rotational shaft as the upper surface plate and the lower surface plate; and a planetary carrier in which a holding hole that holds a workpiece is formed and which revolves while rotating in engagement with the sun gear and the internal gear,
 the grinding method comprising:   having the holding hole in the planetary carrier provided with a cutaway in a side of the holding hole that contacts a side surface of the workpiece when the planetary carrier rotates, and   holding the workpiece in the cutaway-provided holding hole in the planetary carrier and grinding at least one surface of the workpiece between the upper surface plate and the lower surface plate.