The production of a Nd-Fe-B permanent magnet by a hydrogen decrepitation/attritor milling route

1986 ◽  
Vol 21 (11) ◽  
pp. 4107-4110 ◽  
Author(s):  
P. J. McGuiness ◽  
I. R. Harris ◽  
E. Rozendaal ◽  
J. Ormerod ◽  
M. Ward
Keyword(s):  
Permanent Magnet ◽  
Attritor Milling ◽  
Hydrogen Decrepitation

scholarly journals Behaviours of Hydrogen Decrepitation in R-Fe-B Type Permanent Magnet Alloy.

1997 ◽  
Vol 44 (1) ◽  
pp. 90-95 ◽  
Author(s):  
Akihiko Saguchi ◽  
Wataru Takahashi ◽  
Yuji Kaneko ◽  
Naoyuki Ishigaki
Keyword(s):  
Permanent Magnet ◽  
Magnet Alloy ◽  
Hydrogen Decrepitation ◽  
Permanent Magnet Alloy

NEW PERMANENT MAGNET DEVICES

1984 ◽  
Vol 45 (C1) ◽  
pp. C1-285-C1-291 ◽  
Author(s):  
R. Pauthenet
Keyword(s):  
Permanent Magnet

A novel analytical calculation of magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping

2020 ◽  
pp. 1-15
Author(s):  
Jianqi Li ◽  
Yu Zhou ◽  
Jianying Li
Keyword(s):  
Magnetic Field ◽  
Conformal Mapping ◽  
Permanent Magnet ◽  
Flux Density ◽  
Analytical Method ◽  
Electromotive Force ◽  
Analytical Calculation ◽  
Air Gap ◽  
Permanent Magnet Machines ◽  
Peak Value

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.

Performance analysis of magnetic gear with Halbach array for high power and high speed

2020 ◽  
Vol 64 (1-4) ◽  
pp. 959-967
Author(s):  
Se-Yeong Kim ◽  
Tae-Woo Lee ◽  
Yon-Do Chun ◽  
Do-Kwan Hong
Keyword(s):  
Permanent Magnet ◽  
Eddy Current ◽  
High Power ◽  
High Speed ◽  
Torque Ripple ◽  
Eddy Current Loss ◽  
Element Analysis ◽  
Current Loss ◽  
Halbach Array ◽  
Magnetic Gear

In this study, we propose a non-contact 80 kW, 60,000 rpm coaxial magnetic gear (CMG) model for high speed and high power applications. Two models with the same power but different radial and axial sizes were optimized using response surface methodology. Both models employed a Halbach array to increase torque. Also, an edge fillet was applied to the radial magnetized permanent magnet to reduce torque ripple, and an axial gap was applied to the permanent magnet with a radial gap to reduce eddy current loss. The models were analyzed using 2-D and 3-D finite element analysis. The torque, torque ripple and eddy current loss were compared in both models according to the materials used, including Sm2Co17, NdFeBs (N42SH, N48SH). Also, the structural stability of the pole piece structure was investigated by forced vibration analysis. Critical speed results from rotordynamics analysis are also presented.

Analysis of structure factors affecting suspension force of permanent magnet system with variable magnetic flux path control

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1495-1504
Author(s):  
Fangchao Xu ◽  
Yongquan Guo ◽  
Ran Zhou ◽  
Junjie Jin ◽  
Chuan Zhao ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
System Structure ◽  
Magnet System ◽  
Load Torque ◽  
Factors Affecting ◽  
Annular Gap ◽  
Path Control ◽  
Structure Factors ◽  
Flux Path

To solve the problem of reduction of suspension force of permanent magnet system with variable magnetic flux path control, according to the structure of the system, suspension principle of the permanent magnet system with variable magnetic flux path control and the generation principle of the load torque, the influence of the mechanical structure of the system on the suspension force is analyzed by changing part of parameters of the system structure. The results show that the existence of magnetic isolation plate is the main reason for the decrease of suspension force, the permanent magnet ring can be thickened to 11.91 mm, the annular gap can be reduced to 1 mm, thickness of the “F” shaped magnetizer can be increased to 9 mm to increase the suspension force.

Influence of unbalanced magnetic force on shaft deflection in permanent magnet synchronous motor with fractional slot concentrated windings

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1461-1468
Author(s):  
Ting Dong ◽  
Juyan Huang ◽  
Bing Peng ◽  
Ling Jian
Keyword(s):  
Permanent Magnet ◽  
Magnetic Force ◽  
Permanent Magnet Synchronous Motor ◽  
Operational Reliability ◽  
Topology Structure ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors ◽  
Shaft Deflection ◽  
Large Length ◽  
Fractional Slot

The calculation accuracy of unbalanced magnetic forces (UMF) is very important to the design of rotor length, because it will effect the shaft deflection. But in some permanent magnet synchronous motors (PMSMs) with fractional slot concentrated windings (FSCW), the UMF caused by asymmetrical stator topology structure is not considered in the existing deflection calculation, which is very fatal for the operational reliability, especially for the PMSMs with the large length-diameter ratio, such as submersible PMSMs. Therefore, the part of UMF in the asymmetrical stator topology structure PMSMs caused by the choice of pole-slot combinations is analysized in this paper, and a more accurate rotor deflection calculation method is also proposed.

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