Evaluation of a bearingless PM motor with wide magnetic gaps

Junichi Asama, Miya Amada, Norimasa Tanabe, Naoya Miyamoto, Akira Chiba, Satoru Iwasaki, Masatsugu Takemoto, Tadashi Fukao, M. Azizur Rahman

Research output: Contribution to journalArticlepeer-review

44 Citations (Scopus)


A new noncontact drive system has been developed employing a consequent-pole-type bearingless permanent magnet (PM) motor and a thrust magnetic bearing. This bearingless motor has a wide magnetic gap. The wide magnetic gap may cause a decrease in radial magnetic suspension force because of an increase in magnetic reluctance. A thrust magnetic bearing is installed at the end of the shaft because strong thrust force exists in centrifugal pump applications. In this paper, the magnetic suspension forces and rotation characteristics of the experimental prototype are evaluated while the rotor is magnetically suspended. Experimental results are also compared to the calculated ones using the finite-element method. It is demonstrated that the developed consequent-pole-type bearingless PM motor possesses sufficient magnetic suspension force for noncontact operation.

Original languageEnglish
Article number5422659
Pages (from-to)957-964
Number of pages8
JournalIEEE Transactions on Energy Conversion
Issue number4
Publication statusPublished - Dec 2010
Externally publishedYes


  • Bearingless motor
  • centrifugal pump
  • consequent pole
  • magnetic bearing
  • permanent magnet (PM) motor
  • wide gap

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering


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