Application of Polar Anisotropic NdFeB Ring-Type Permanent Magnet to Brushless DC Motor

Author

Kim, Hyo Jun ; Kim, Dong Hwan ; Koh, Chang Seop ; Shin, Pan Seok

Author_Institution

R&D Center of JahwaElectron. Co. Ltd, Chungbuk

Volume

43

Issue

6

fYear

2007

fDate

6/1/2007 12:00:00 AM

Firstpage

2522

Lastpage

2524

Abstract

A four-pole polar anisotropic sintered NdFeB permanent magnet (PM) with high surface magnetic flux density is developed using a dry pressing process with pulse magnetizing fields. The effects of powder-filling density, magnetic field intensity, distribution in the cavity, and premagnetization of the powder on the magnet performance are investigated. Through an application of the developed PM to a brushless DC motor, it is shown that the premagnetization of the powder is very effective for increasing the surface magnetic flux density. Experimental results with a brushless DC motor adopting the developed PM shows that the surface magnetic flux density is increased up to 0.63 T, and the back emf at 1000 rpm measured 2.7 V, which is 41% higher than the conventional segment type PM

Keywords

boron alloys; brushless DC motors; iron alloys; magnetic anisotropy; magnetic flux; neodymium alloys; permanent magnet motors; powder metallurgy; pressing; sintering; NdFeB; brushless DC motor; cavity; dry pressing process; high surface magnetic flux density; magnetic field intensity; permanent magnet; polar anisotropic ring; powder-filling density; pulse magnetizing fields; Anisotropic magnetoresistance; Brushless DC motors; Density measurement; Magnetic anisotropy; Magnetic flux; Magnetic flux density; Permanent magnets; Perpendicular magnetic anisotropy; Powders; Pressing; BLDC motor; permanent magnet (PM); polar anisotropic; sintered;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2007.892856

Filename

4202799