A Performance Evaluation of the Ultraprecision Machine Tool using Twist-roller Friction Drive Mechanisms

摘要

The quality of a mirror surface machined by a three-axis Ultraprecision machine tool is evaluated. The Twist-roller Friction Drive (TFD) employed in the feed drive mechanism of the machine tool affects the quality of machined surface because lateral forces induced in the TFD vibrate the machine table. By using the Active Inherent Restrictor (AIR), pneumatic pressure on the aerostatic guideway of the machine tool is controlled to decrease lateral vibration of the table. Single point diamond turning of an aluminum alloy performed on the machine tool shows the effect of active control: the amplitude of the waviness of the machined surface synchronized with the rotation of the TFD can be decreased to be in the order of ten-nanometer. Without active control, the straightness of the machined surface is greater than 0.2 μm, while, the straightness is improved to be 0.1 μm with active control.