Rotational feedthrough using ultrasonic motor for high vacuum condition

A vacuum environment is indispensable for various measurement devices. To make the use of these devices easy, the mechatronics systems for vacuum conditions, for example, a sample stage, should be advanced. In this paper, we propose a rotational feedthrough using an ultrasonic motor. An ultrasonic motor has many advantages, and is suitable for achieving vacuum conditions. However, the piezoelectric material might be a source of outgas and may hinder the baking treatment. Therefore, the piezoelectric part is arranged outside the vacuum chamber. The driving mechanism is a mode-rotation motor. The stator transducer was a bolted Langevin vibrator for generating bending vibration. This motor was successfully operated under a vacuum condition of 2 x 10(-6) Pa. The endurance of the motor and the change of the vacuum level were measured and discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.