磁流变液与电热形状记忆合金联合传动性能研究

Research on Combined Transmission Performance of Magnetorheological Fluid and Electrothermal Shape Memory Alloys

针对磁流变液装置所产生的转矩偏小的问题,提出了一种磁流变液与电热形状记忆合金(SMA)联合传动的方法,并介绍了传动装置的工作原理。基于电热SMA弹簧力学特性,推导了温度与摩擦转矩的关系;通过有限元软件对装置进行了磁场分析,得到了环形磁流变液工作间隙磁场强度与磁流变液剪切屈服应力之间的关系,并计算得出磁流变液传递的转矩。实验结果表明:由8个SMA弹簧产生的摩擦转矩最大为1.798 N·m,励磁线圈的电流为1 A、匝数为380时,磁流变液传递的转矩为1.41 N·m。相较于单一的磁流变液传动装置产生的转矩,磁流变液与电热SMA联合传动产生的转矩为3.15 N·m,传动性能提高了1.2倍。

In order to solve the problems of small torque produced by magnetorheological fluid devices,a method of combined transmission of magnetorheological fluid and electrothermal shape memory alloys was proposed and the operating principle of the transmission devices was introduced.The relationship between temperature and friction torque was deduced based on the mechanics characteristics of electrothermal shape memory alloy springs,the magnetic fields of the devices were analyzed by finite element software,and the magnetic field strength and shear yield stress of magnetorheological fluid in working gaps of ring magnetorheological fluid were analyzed,and the transfer torque of magnetorheological fluid was calculated.The experimental results show that the friction torque caused by 8 shape memory alloy springs is as 1.798 N·m.When the current of the excitation coil is as 1A and the number of turns is as 380,the torque transmitted by magnetorheological fluid is as 1.41 N·m.Compared with the torque produced by a single magnetorheological fluid drives,the combined drives of magnetorheological fluid and electrothermal shape memory alloy generates a torque of 3.15 N·m,which improve the transmission performance by 1.2 times.