鼠笼式同心磁齿轮结构设计与有限元分析

Structural Design and Finite Element Analysis of SquirrelCage Concentric Magnetic Gear

针对同心式永磁齿轮机械强度低、振荡严重以及生产成本高等问题,基于磁力传动原理及电磁感应定律,提出一种鼠笼式同心磁齿轮结构,将鼠笼替换内磁圈不仅节约了成本、提高了机械强度,而且增大机构磁阻,降低了运行时振荡幅度;根据静磁场理论,阐述了鼠笼式同心式永磁齿轮的运行机理,建立了转速及转矩模型,并经有限元算例证明了所建模型的正确性;基于动量矩定理,分析了转动惯量与负载能力的影响关系,越大,CPMG负载能力越弱,鼠笼式CPMG减小了内磁圈转矩惯量,可有效提高负载能力;通过对鼠笼导条数与运行稳定性的数理分析,得出当增大鼠笼导条数时,即增大磁阻k可有效减小转速波动的幅值;通过对转矩数理分析,鼠笼式CPMG通过电磁感应产生耦合磁场,与内、外磁圈相对位置无关,降低了CPMG启动难度.

According to the principle of magnetic transmission and the electromagnetic induction law,a kind of squirrel-cage concentric magnetic gear structure is proposed to solve the problem of concentric permanent magnet gear with low mechanical strength,serious oscillation and high production costs.Based on static magnetic field theory,the operation mechanism of the squirrel-cage concentric permanent magnet gear is described,and the speed and torque model are established.The correctness of the model is proved by finite element method,and the momentum moment theorem is employed to analyze the relationship between the moment of inertia and the load capacity.The study shows that the larger moment of inertia results weaker CPMG load capacity.On the other hand,squirrel cage CPMG reduces the torque moment of the inner coil,which will improve the load capacity effectively.The relationship between the number of rods and the running stability is analyzed by numerical method,and it is concluded that increasing the numbers of squirrel cage guide,that is,increase the magnetic resistance k,can reduce the amplitude of the speed fluctuations effectively.After the mathematical analysis of the torque,it is found that the CPMG produces a coupled magnetic field by electromagnetic induction,which is independent of the relative position of the inner and outer magnetic disks and reduces the difficulty of starting the CPMG.