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Title: Study of permanent-magnet couplings with progressive magnetization using an analytical formulation

Abstract

Permanent-magnet (PM) magnetic couplings are used in many industrial applications. They allow the transmission of a torque from a rotating part to another rotating part without any mechanical contact. They are used in sealed equipment to transmit a movement through a separation wall. They are also very useful in high security applications to avoid failures due to torque overload. Nonclassical structures of permanent-magnet cylindrical air-gap couplings with progressive magnetization are studied. In these couplings, parallelepiped magnets with nonclassical magnetization direction are used and stuck in ironless cores. The magnetization direction of each magnet is chosen to provide an optimal repartition of the induction in the air gap. This progressive magnetization allows very high values of pullout torque. The use of this type of structure with ironless cores and very high pull-out torque seems to be an advantageous way to minimize the inertia and maximize the pullout torque of a magnetic coupling. An efficient method to calculate the torque of such a coupling is presented, based on analytical formulas for forces between magnets. It allows the exact evaluation of the performance of the studied couplings when the main dimensions of the coupling are varying with small calculation time. In this papermore » the influence of the number of pole pairs, the influence of the number of magnets per pole, the influence of the magnets' thickness, the influence of the air-gap radius, and the influence of the length of the structure are studied and discussed. Then some general rules are presented for efficient design of such a coupling.« less

Authors:
;
Publication Date:
Research Org.:
Lab. d'Electrotechnique et de Magnetisme de Brest (FR)
OSTI Identifier:
20000589
Resource Type:
Journal Article
Journal Name:
IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers)
Additional Journal Information:
Journal Volume: 35; Journal Issue: 5Pt3; Other Information: PBD: Sep 1999; Journal ID: ISSN 0018-9464
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; PERMANENT MAGNETS; COUPLINGS; MAGNETIZATION; TORQUE; PERFORMANCE; DESIGN; ANALYTICAL SOLUTION

Citation Formats

Charpentier, J.F., and Lemarquand, G. Study of permanent-magnet couplings with progressive magnetization using an analytical formulation. United States: N. p., 1999. Web. doi:10.1109/20.799069.
Charpentier, J.F., & Lemarquand, G. Study of permanent-magnet couplings with progressive magnetization using an analytical formulation. United States. doi:10.1109/20.799069.
Charpentier, J.F., and Lemarquand, G. Wed . "Study of permanent-magnet couplings with progressive magnetization using an analytical formulation". United States. doi:10.1109/20.799069.
@article{osti_20000589,
title = {Study of permanent-magnet couplings with progressive magnetization using an analytical formulation},
author = {Charpentier, J.F. and Lemarquand, G.},
abstractNote = {Permanent-magnet (PM) magnetic couplings are used in many industrial applications. They allow the transmission of a torque from a rotating part to another rotating part without any mechanical contact. They are used in sealed equipment to transmit a movement through a separation wall. They are also very useful in high security applications to avoid failures due to torque overload. Nonclassical structures of permanent-magnet cylindrical air-gap couplings with progressive magnetization are studied. In these couplings, parallelepiped magnets with nonclassical magnetization direction are used and stuck in ironless cores. The magnetization direction of each magnet is chosen to provide an optimal repartition of the induction in the air gap. This progressive magnetization allows very high values of pullout torque. The use of this type of structure with ironless cores and very high pull-out torque seems to be an advantageous way to minimize the inertia and maximize the pullout torque of a magnetic coupling. An efficient method to calculate the torque of such a coupling is presented, based on analytical formulas for forces between magnets. It allows the exact evaluation of the performance of the studied couplings when the main dimensions of the coupling are varying with small calculation time. In this paper the influence of the number of pole pairs, the influence of the number of magnets per pole, the influence of the magnets' thickness, the influence of the air-gap radius, and the influence of the length of the structure are studied and discussed. Then some general rules are presented for efficient design of such a coupling.},
doi = {10.1109/20.799069},
journal = {IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers)},
issn = {0018-9464},
number = 5Pt3,
volume = 35,
place = {United States},
year = {1999},
month = {9}
}