Research On A Novel Field Modulated Magnetic Gear

Magnetic gears offer significant potential advantages compared withmechanical gears, such as reduced maintenance and improved reliability, inherentoverload protection, and physical isolation between the input and output shafts,low noise and vibration. But the torque transmission capability of them isrelatively poor. A new field modulated magnetic gear(Field Modulated MagneticsGear, FMMG), because of the full use of permanent magnet, can supply the samecompetitive torque transmission as mechanical gears, even better. In this thesis,the FMMG is deeply researched and the main corresponding work is as follows.Firstly, because of its special structure, the basic operating principle ofFMMG is elaborated by the analytical method. The corresponding mathematicalexpression of the pole pairs of permanent magnet in the inner rotor and outerrotor and the numbers of the magnetic blocks of the modulator ring is derivated.Besides, the mathematical model of speed and torque of the inner rotor, the outerrotor and modulator ring is established, and then validated and further elaboratedby two-dimensional finite element.Secondly, Secondly, the static torque characteristics and the stable torquecharacteristics, under four different operating modes, are researched, the causesof torque ripple is analysed and the corresponding solution is also put up. Thenthe dynamic performance of FMMG under step response and excess load torqueare studied.Thirdly, how to choose the best programs according to the differentrequirements of the workplace is analyzed. And then series of relatedoptimization work are carried on.Lastly, iron loss is the main loss of FMMG, so based on the generatingmechanism of the core loss, the basic distribution law of the magnetic field and the corresponding core loss in the inner rotor, outer rotor, PMs, modulator ring isresearched, providing a theoretical basis for the efficiency and temperature risecalculations. Besides, the effective method to reduce the permanent magnet eddycurrent loss is put forward. Then, the stress calibration of modulator ring iscarried on.