246 Seismic Isolation System with Convertible Active and Passive Modes Using Linear Motors for Monocrystal Pullers

Abstract

This paper describes seismic isolation system for monocrystal pullers. In the monocrystal puller, a monocrystal is suspended by a wire through a very thin neck and grows longitudinally as it is pulled up very slowly from the molten material. The neck is easily broken due to collision between the monocrystal and the wall of the puller caused by even weak earthquakes. In this study, an active isolation system using linear motors has been developed because the linear motors are most suitable actuators for this purpose. Through shake table tests, it was shown that the active isolation system could effectively reduce the displacement of the monocrystal model.