Analytical Method for Magnetic Field of Eccentric Magnetic Harmonic Gear

Libing Jing,Tong Ben,Jun Gong

doi:10.1109/access.2020.2974777

Libing Jing, Tong Ben + Show 1 more

Open Access

https://doi.org/10.1109/access.2020.2974777

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Abstract

Eccentric magnetic harmonic gears (EMHG) can achieve high speed ratio transmission and large torque output by modulating the air gap length between permanent magnets (PM). The analytical method is based on the boundary perturbation method. The vector magnetic potential perturbation equation in the air gap region is established, and the general solution is obtained using the boundary conditions. According to the superposition principle, the air gap flux density of stator and rotor PMs acting alone is synthesized, and the electromagnetic torque and unbalanced magnetic pull are calculated. Last, we compare magnetic field distributions, electromagnetic torque and unbalanced magnetic pull computed by the analytical method with those obtained from finite-element method (FEM).

Highlights

INTRODUCTIONMagnetic gears (MG) can offer several advantages, namely, low noise, less friction, no lubrication, high reliability etc
Compared with mechanical gears, magnetic gears (MG) can offer several advantages, namely, low noise, less friction, no lubrication, high reliability etc
Eccentric magnetic harmonic gear (EMHG) has been proposed, their torque density and transmission ratio are much larger than concentric magnetic gear (CMG) [3], [4]

Summary

INTRODUCTION

Magnetic gears (MG) can offer several advantages, namely, low noise, less friction, no lubrication, high reliability etc. Eccentric magnetic harmonic gear (EMHG) has been proposed, their torque density and transmission ratio are much larger than CMGs [3], [4]. The free rotation of the rotor can be achieved without the constraint of meshing It is suitable for calculating the magnetic field of magnetic gear with eccentric rotor. In [17], an analytical model is developed for the prediction of the air gap flux density in the eccentric permanent magnet inset machines at no-load and on-load conditions, which is fast and accurate. According to the superposition principle, the air gap magnetic field of EMHG is synthesized and the electromagnetic torque and unbalanced magnetic pull are calculated. The analytical results are verified with the finite-element method (FEM)

ANALYTICAL MODEL

ANALYTICAL MODEL OF EMHG

APPLICATION EXAMPLE

CONCLUSION