超精密位置泀め用空気坮サーボ輘受アクチュェータ（第1報）:システム表琭に基づくアクチュエータの基本特性の提示

摘要

A pneumatic servo bearing actuator for ultraprecise positioning consisting of a servo amplifier, a pneumatic servo valve and an aerostatic bearing is proposed as a new actuator construction in this study. As the first step of the study, this report presents a system representation of the actuator on the concept of lumped-parameter bearing model and four-terminal circuit theory, where the input parameters are the pressure controlled by a servo valve and the mass flow into the bearing clearance, while the output ones are the load capacity of the bearing (thrust force of the actuator) and the bearing gap (displacement of the actuator). Fundamental characteristics of the actuator - rated thrust force, stiffness, damping coefficient and dynamic response - are presented through the system representation, and its potential to realize an ultraprecise positioning is comprehensively discussed.%近年，次世代半導体製造装置，MEMS/NEMS，ナノバイオニrnクス，ナノインプリント，ナノ計測・分析装置等の開発，発展rnとともに，超精密位置決め機構の需要はますます高まってきてrnいる．それらに要求される位置決め精度は，数ナノ又はサブナrnノであり，極めて厳しぃ，これら超精密位置決めを実現するたrnめに，現在では，電動リニアモータや圧電素子から成るアクチrnュエータが頻繁に使用されてぃる1）．しかしながら，これらのァrnクチュェータは電気的に駆動力を得るものであり，コイルや素rn子から発生する熱が位置決め性能の低下を招くとぃう課題を抱rnえてぃる．