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

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

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References

Agency for Natural Resources and Energy: Japan’s energy 20 Questions to understand the current energy situation (online), available from https://www.enecho.meti.go.jp/en/category/brochures/pdf/japan_energy_2016.pdf, (accessed on 30 September, 2019).

Okada

Suzuki

Matsuda

K.-I.

Kondo

and Enokizono

, Development of highly efficient magnetic bearing and application to ultra-low temperature fluid pump, Mechanical Engineering Journal2(4) (2015), doi:10.1299/mej.15-00086.

Komori

and Uchino

, Development of a liquid nitrogen pump using superconducting bulk motor, IEEE Trans. on Applied Superconductivity14(2) (2004), 1659–1662.

Okada

, Foundations and applications of magnetic bearings, Youkendo (1995), p. 176 (in Japanese).

Ueno

and Okada

, Characteristics of axial force and rotating torque and their control of permanent magnet type axial gap self-bearing motor, Electrical Engineering in Japan132(1) (2000), 81–91.

Ueno

Iseki

and Jiang

, Stability of a tilt-controlling axial gap self-bearing motor with single-stator, Mechanical Engineering Journal4(4) (2017), doi:10.1299/mej.16-00337.

Sun

Chen

and Yang

, Overview of bearingless permanentmagnet synchronous motors, IEEE Transactions on Industrial Electronics60(12) (2013), 5528–5538, doi:10.1109/TIE.2012.2232253.

Sun

Tang

and Shi

, Design of a bearingless outer rotor induction motor, Energies10(5) (2017), doi:10.3390/en10050705.

Wellerdieck

Nussbaumer

and Kolar

J. W.

, Experimental verification of an angle-sensorless control scheme for bearingless permanent magnet machines, Mechanical Engineering Journal4(5) (2017), doi:10.1299/mej.17-00003.

10.

Hirose

Komori

Asami

and Sakai

, Application of one-axis-controlled magnetic bearing with a hollow shaft to noncontact rotation drive, IEEE Trans. on Magnetics51(11) (2015), 1–4, doi:10.1109/TMAG.2015.2448551.