Spin Motion of a Magnet Levitated over a High -Tc Superconductor Excited Vertically

Toshihiko Sugiura, Tsuvoshi Tanaka, Takuo Kugiya, Masatsugu Yoshizawa

Research output: Contribution to journalArticlepeer-review


This research deals with nonlinear dynamics of a permanent magnet freely levitated above a high-Tc superconductor excited in the vertical direction, focusing on generation of spin torque acting on the magnet. Equations of 6 d.o.f. motion, nonlinearly coupled by magnetic force and torque, were described on the assumption that a magnet has an eccentricity between the center of gravity and the magnetic center. Force and torque were evaluated analytically by the advanced mirror image method. Dynamic behavior of the magnet was examined numerically for different frequencies of excitation. A simplified 2 d.o.f. system with only essential terms was introduced in order to discuss the mechanism of nonlinear coupling which generates spinning from vertical oscillation. spinning motion of the magnet was examined in detail by the method of harmonic balance. Experiments of vertical excitation were carried out. Experimental results were compared with numerical and analytical ones.

Original languageEnglish
Pages (from-to)59-66
Number of pages8
JournalNihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C
Issue number653
Publication statusPublished - 2001


  • Coupled Vibration
  • Electromagnetic Force
  • Nonlinear Coupling
  • Rotor Dynamics
  • Superconducting Levitation

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering


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