永磁激励下磁流变安全联轴器物理场数值仿真计算与分析

设计了一种新型磁流变安全联轴器,该联轴器以磁流变胶作为传力介质,以Halbach永磁排列作为磁场激励源。在COMSOL Multiphysics环境下建立了三维有限元分析模型;利用Bingham磁致本构模型对自行研制的磁流变胶的剪切屈服应力和粘度进行最小二乘5次多项式拟合,得到了剪切屈服应力和粘度随磁通密度的变化曲线参数;并将磁流变胶的拟合参数及其磁化特性嵌入COMSOLMultiphysics有限元计算环境中,最终得到磁流变胶所在区域的磁通密度云分布以及两个指定位置的剪切屈服应力和粘度在极坐标下的周向分布。研究结果表明:安全联轴器里层区域的磁通密度分布明显具有Halbach排列特点和明显的区域分布特性;磁通密度、剪切屈服应力、粘度在两个指定位置的周向分布具有明显的对称性;可以通过去掉外层磁流变胶所在区域来达到结构的小型化和轻量化,也能够保证联轴器的传递扭矩不发生较大幅度的降低。本研究能够在联轴器的设计阶段提供一定的指导。

Numerical simulation and analysis of transmission characteristics of safety coupling based on MR gel under Halbach permanent magnet arrangement

A new type of MR safety coupling is designed in this paper, which uses MR gel as the transmission medium and Halbach array as the excitation source of magnetic field. A three-dimensional finite element analysis model is established under COMSOL Multiphysics environment. The shear yield stress and viscosity of self-developed MR gel are fitted by Bingham mode with least squares to obtain their curve parameters;and the fitting parameters and magnetization characteristics of MR gel are embedded in COMSOL Multiphysics. Finally, the distribution of magnetic flux density, shear yield stress and viscosity in the MR gel region are obtained. The main research results show that: the magnetic flux density distribution in the inner layer of the safety coupling obviously has the characteristics of Halbach arrangement and obvious regional distribution;the circumferential distribution of magnetic flux density, shear yield stress and viscosity at two designated positions has obvious symmetrical structure;the structure can be miniaturized and lightweight by removing the area where the outer layer of the magnetorheological adhesive is located, which is the same as that of the outer layer. It ensures that the transmission torque of the coupling does not decrease greatly. This study is of some guidance in the design of MR coupling.