蛇形磁路多片式磁流变液阻尼器设计

Design of multi-disc MRF damper with serpentine flux path

提出了一种大输出阻尼力矩,低初始阻尼力的小体积多片式磁流变液阻尼器的设计方法。阻尼器内部的导磁元件、隔磁元件和间隙中磁流变液构成闭合的蛇形磁路。针对漏液的问题采用铁磁密封的设计思想,显著减小了转轴处的摩擦力。基于Bingham塑性模型分析了磁流变液的力学特性,导出了阻尼器的力矩模型,采用ANSYS Maxwell软件对阻尼器进行了有限元分析,验证了磁路的准确性,并在原始设计的基础上对阻尼器的结构进行了优化,研制出了一种小体积磁流变液阻尼器。在自主搭建的实验平台上进行力矩测量实验和响应时间测量实验,实验结果验证了该阻尼器具有大输出力矩,低初始阻尼力和低响应时间的特点。阻尼器的直径为33.6 mm,高度为21.6 mm,重约200 g,当输入电流为1.2 A时,产生的力矩为350 N·mm,达到了操作者抓取虚拟物体所需的力矩。

The design method of a new type multi-disc MRF damper with large output damper torque,low initial damper force is introduced. The magnetic elements,non-magnetic elements and magneto rheological fluid（ MRF） in the gap constitute a closed serpentine flux path inside the damper. Aiming at the leakage problem,the design idea of ferro-fluidic sealing is adopted,which significantly reduces the friction force at the rotating shaft. Based on the Bingham plastic model,the paper analyzes the mechanical characteristics of MRF,and derives the damper torque model. The ANSYS Maxwell software is used to conduct the finite element analysis of the damper,which verifies the accuracy of the flux path,and then the structure of the damper is improved on the basis of the original design. Finally,a small volume MRF damper was developed. An experiment platform was built by our own, on which torque measurement experiment and response time measurement experiment were carried out; the experiment results verify that the damper has the characteristics of large output torque,low initial damping force and low response time. The diameter of the damper is 33.6 mm,its height is 21.6 mm,and the weight is about 200 g; when the input current is 1. 2 A,the output torque is about 350 N · mm,which reaches the required torque for the operator to grasp virtual objects.