Super-Clean Actuator For Machines And Robots

Abstract

In view of the fact that the cleanliness of production environment greatly affects the reliability and yield rate of semi-conductor circuits, the authors have developed a contactless actuator intended for use in clean rooms and vacuums. The devised actuator is a stepping motor with a function of magnetic suspension. Thus the motor has the propelling and positioning ability of an ordinary stepping motor, and at the same time that of contactless guiding and support by magnetic suspension. Owing to the characteristic toothed pole structure of the stepping motor, its structure and driving conditions were optimized to minimize the possible fluctuation of the attractive force acting between the stator and rotor. From experiments, gap fluctuation amplitude has been confirmed to be no greater than 1% of preset gap length. In this paper, the structure and design of the motor are introduced. Also, the structure and basic performance of three types of linear and rotary contactless positioning mechanisms using the devised motor are introduced. The use of the motor as super-clean DD motor for machines and robots is expected.