Study of Permanent Magnet Bearings and their Stiffness

Document Type : Persian

Authors

1 Lecturer, Department of physics, Shahr-e-Qods Branch, Islamic Azad university, Tehran, Iran

2 M.Sc., Department of Mechanical Engineering, Cleveland State University, U.S.A

3 Assistant Professor, Department of Mechanical Engineering, Cleveland State University, U.S.A

Abstract

A typical passive magnetic bearing has been modeled and analyzed for its performance characteristics. The magnetic bearing studied in this work comprised of a Shaft, inner magnets sleeved over the shaft, and outer magnetic rings. A detailed analysis has been perform on the force exerted by a permanent magnet on the shaft nurture to restore the shaft to its equilibrium position when an eccentricity is induced between the magnet and the shaft . A relation between the force exerted and the displacement of the shaft from its equilibrium position has been developed hence determining a specific stiffness value.

Keywords


[1] Wikipedia, Free encyclopedia, Earnshow,s theorem, 1842.
[2] Backers F.T., A magnetic journal bearing, Phillips Tech. Rev., vol.22, 1961, pp.232- 238.
[3]Yonnet J.P., Permanent magnet bearings and couplings, IEEE Transactions on Magnetics, vol.17, No.1, 1981, pp. 1169-1173.
[4]Yonnet J.P., Lemarquand G., Hmmerlin S., and Olvierrulliere E., Stacked Structures Of Passive Magnetic Bearings, Jounnal  of Applied Physics, Vol.70, No.10, 1991, pp.6633-6635.
[5]Marinescu M., and Marinescu N., A New Improved Method for Computation of  Radial Stiffness in Permanent Magnet Bearings, IEEE Trans. Magn., Vol.30, No.5, 1994, pp.3491-3494.
[6]Paden B., Groom N., Antaki J.F., Design Formulas for Permanent- Magnet Bearings, Transactions of the ASME, Vol.125, 2003, pp.734-738.
[7]Meeker D., Radial Magnetic Bearing: Example, 1999.
[8]Siebert M., Passive Magnetic Bearing Development, 2002.
[9]Beach R.F., Aerospace Power and Electronics Simulation Workshop, Concurrent Engineering Design practice foe Aerospace Power, NASA, 2003.
[10]Dirusso E., Passive Magnetic Bearings With Ferrofluid Stabilization, Lewis Research Center, Cleveland, Ohio, 1996.
[11]Clark D.J., Clark M.J., and Montague G.T., Overview of Magnetic Bearing Technology for Gas Turbine Engines, 2004.
[12]AMSAT-P 3D Magnetic Bearing Momentum Wheel, International Symposium on small Satellites, France, 1996.