| 摘要 |
PURPOSE: To suppress irregular wear and maintain the machining accuracy without degradating the rate of operation by forming an upper and a lower lapping surface plate so that they have differing anti-abrasiveness in the radial direction, and forming the part where the relative speed of the object to be machined with the surface plates is large, from a material having a high anti- abrasiveness. CONSTITUTION: An object to be machined 14 is held by a carrier 7 and polished between an upper and a lower lapping surface plate 9, 1. Therein the carrier 7 orbits counterclockwise round a sun gear 8 while it makes counterclock rotation round its own axis under the conditions that both the sun gear 8 and an internal gear 6 are rotated counterclockwise, that the rotating speed of the sun gear 8 is smaller than that of the internal gear 6, and that the upper and lower surface plates 9 and 1 rotate clockwise and counterclockwise, respectively. The periphery of the upper surface plate 9 is made of a material having a high anti-abrasiveness because the peripheral part has a large relative speed with the object to be machined 14 and wears quickly, while the bore of the lower surface plate is made of material having a high anti-abrasiveness because this bore part has a large relative speed and wears quickly. |
