回転４軸型クリーンロボットの開発

Abstract

This paper describes design strategies and experimental results of the clean room robot which has airborne particle emission levels well within Class 1. Recently, there has been an increasing demand for clean room robots in the fields of semiconductor manufacturing, biotechnology, medical supplies, and so on. And a lot of SCARA type or Cartesian coordinates type clean room robots are developed for practical robots. These conventional robots perform a linear motion by a prismatic joint ; they have a defect in the structure for high degrees of cleanliness. Therefore, these robots utilize a linear-motion-cover such as a bellows and negative pressure by vacuum suction within the arm. To solve this problem, the proposed robot has a four axes pseudo-SCARA configuration with four revolute joints using a parallelogram arm mechanism ; cleanliness Class 1 is achieved by utilization magnetic fluid seals for all revolute joints without vacuum suction. Furthermore, a 32 bit high performance controller is used for reducing the effective current of the motors and a finite element method is used for reducing the moment of inertia while keeping the stiffness of the arm high. As a result, maximum speed 6 m/s and cycle time 0.98 second are achieved.