磁流变传动装置多种工况下热结构场研究

Research on Thermal Structure Field of Magnetorheological Device Under Multiple Working Condition

针对高温条件下磁流变液剪切应力、热磁化强度、黏度和流变特性显著降低,以及热应力对磁流变液链化结构的破坏,严重影响磁流变传动装置性能的问题,基于剪切模量与磁场强度的非线性关系,推算了磁场作用下磁流变液固化状态的弹性模量;研究了在滑差和励磁线圈功率损失工况下磁流变液的温度、热变形以及等效热应力分布规律;探讨了滑差功率、电流、间隙宽度和励磁线圈绕组级数对其的影响。研究结果表明,滑差功率和励磁线圈生热都会造成磁流变液温度显著升高,由此产生的热变形对结构影响较小,而等效热应力影响较大;磁流变液工作间隙与非工作间隙的等效热应力分布存在明显差异;可在滑差和电流不变的情况下通过改变间隙宽度和绕组级数提高磁流变传动装置的性能。

The shear stress,the thermal magnetization,the viscosity and the rheological properties of the magnetorheological fluid are significantly reduced under high temperature,and the damage of the thermal stress produced by the high temperature to the chain structure of the magnetorheological fluid seriously affected the transmission performance of the magnetorheological transmission.Based on the nonlinear relationship between shear modulus and magnetic field strength,the elastic modulus of magnetorheological fluid under the action of magnetic field is calculated.The temperature,thermal deformation and the distribution law of the equivalent thermal stress in the magnetorheological fluid gap are studied under the condition of the slip and the power loss of the excitation coil and the influence of the slip power,current,gap width and the winding series of the excitation coil on it is discussed.The results show that both the slip power and the excitation coil current will cause a significant increase in the temperature of the magnetorheological fluid,and the resulting thermal deformation has little influence on the structure,and the equivalent thermal stress is greatly affected.There are obvious differences in the equivalent thermal stress distribution between the working gap and the no working gap of MRF.The performance of magnetorheological transmission device can be improved by changing the width of the gap and the series of windings under the condition of constant slip and current.