Development of one-axis controlled bearingless motor and its application to a centrifugal pump for extremely low temperature

Issue title: Selected papers from the International Symposium on Applied Electromagnetics and Mechanics - ISEM 2019

Guest editors: Jinhao Qiu, Ke Xiong and Hongli Ji

Article type: Research Article

Authors: Kato, Hirohisa^a | Komori, Mochimitsu^a; | Asami, Ken-ichi^a | Sakai, Nobuo^a

Affiliations: [a] Kyushu Institute of Technology, Tobata, Kitakyushu, Fukuoka, Japan

Correspondence: [*] Corresponding author: Mochimitsu Komori, Kyushu Institute of Technology, 1-1 Sensui, Tobata, Kitakyushu, Fukuoka 804-8550, Japan. Email: komori_mk@yahoo.co.jp

Abstract: In this paper, a centrifugal pump for for extremely low temperature was fabricated and evaluated by experiments in liquid nitrogen. The pump is using a bearingless motor and permanent magnet bearings to levitate and rotate the rotor without lubricating oil. The difference from the conventional study is that a one-axis controlled bearingless motor is used to reduce the magnetic bearing cost and that the bearings are installed in the liquid to eliminate a shaft-seal. Stable levitation and rotation of the rotor were confirmed in the rotation and pump experiments in liquid nitrogen. In pump experiment, the flow rate of liquid nitrogen was measured at 1 cm in a pumping height. The maximum flow rate was 1.3 L/min when the rotation speed is 1,800 rpm.

Keywords: Magnetic bearing, bearingless motor, centrifugal pump, low temperature, actuator

DOI: 10.3233/JAE-209447

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 64, no. 1-4, pp. 1287-1294, 2020