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

Journal Article · Wed Sep 01 00:00:00 EDT 1999 · IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers)

DOI:https://doi.org/10.1109/20.799069· OSTI ID:20000589

Charpentier, J F; Lemarquand, G

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.

• Research Organization: Lab. d'Electrotechnique et de Magnetisme de Brest (FR)
• OSTI ID: 20000589
• Journal Information: IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers), Vol. 35, Issue 5Pt3; Other Information: PBD: Sep 1999; ISSN 0018-9464
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
PERMANENT MAGNETS
COUPLINGS
MAGNETIZATION
TORQUE
PERFORMANCE
DESIGN
ANALYTICAL SOLUTION