| Magnetic gear is a kind of transmission device to realize the transmission of force and torque through magnetic coupling,and it has the advantages of no friction,no lubrication,isolation and overload protection,and can realize contact free transmission,etc.As the key part of the high-performance magnetic gear structure,the flux-modulator has greatly improved the utilization ratio of the permanent magnets,and further improved the torque density and transmission efficiency of the magnetic gear.In this paper,the research on the magnetic gear is mainly focus on as follows:(1)The side sinusoidal and side triangle flux-modulators structure are proposed.Firstly,the structure and four working modes of the magnetic gear are introduced,and the slotting ratio is defined.Moreover,the two kinds of flux-modulators structure are parameterized.Secondly,the concept of modulation function is proposed,and the principle of the magnetic gear modulation is analyzed by analytic method.The radial distribution of the magnetic flux density on the air-gap magnetic field under the two conditions of the non flux-modulator and the flux-modulator are calculated by Matlab software,respectively.(2)Finite element simulation analysis of transmission performance of magnetic gear with different flux-modulators.The static magnetic fields of magnetic gear are researched by using of Ansoft 2D finite element analysis software when the inner and outer rotor permanent magnets are separately excited under the two conditions of the non flux-modulator piece and the flux-modulator,respectively.Furthermore,the modulation effect of the flux-modulator on the air-gap magnetic field is analyzed,and compared with the theoretical calculation.The finite element analysis software is used to analyze the relationship between the structural parameters of the side sinusoidal and side triangular flux-modulators and the static torque of the magnetic gear,and the side sinusoidal flux-modulator structure with good static torque performance is selected.The simulation analysis of transmission performance is carried out by using of Ansoft 2D and 3D finite element analysis software when using fan-shaped flux-modulator and side sinusoidal flux-modulator,the amplitude of which curve is2 mm and-2mm,respectively.And the effect of side sinusoidal flux-modulator structure on improving the performance of magnetic gear transmission is analyzed.Base on this,the optimum is selected.(3)The causes of the torque ripple of the magnetic gear are analyzed,including the cogging torque and the harmonic torque.At the same time,the process of forming the cogging torque and the tangential force of the flux-modulator and the waveform of the cogging torque are analyzed when the position of the single permanent magnet relative to the flux-modulator is changed.The composition of the cogging torque of the magnetic gear is analyzed,and the theoretical formulas of various parts of the cogging torque are derived.The influence of air-gap size,radial thickness of flux-modulator,slotting ratio and the amplitude of sinusoidal curve on cogging torque of magnetic gear are simulated by using Ansoft 2D.(4)The side sinusoidal and fan-shaped flux-modulators with a magnetic pole number of 22 are developed,and experimental research on the transmission performance of magnetic gear with two kinds of flux-modulators.The magnetic gear transmission experiment platform is set up,and the magnetic gear inner and outer rotor of the permanent magnet pole are 7 and 15 respectively.Study on transmission performance of magnetic gear experimental platform built by side sinusoidal and fan-shaped flux-modulators,and the no-load loss of the magnetic gear and the different load and input speed are also used.The torque and speed of the magnetic gear of the side sinusoidal and fan-shaped flux-modulators are measured by experiment,and the change law of the torque,speed and transmission efficiency of the magnetic gears under the two different flux-modulators is obtained. |
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