磁场结构对径向流磁流变阀动态性能的影响

Influence of Magnetic Field Structure on Dynamic Performance of Radial Magnetorheological Valve

针对不隔磁径向流磁流变阀磁力线只在径向阻尼间隙中垂直分布导致压降小的不足,提出并设计了一种隔磁径向流磁流变阀。通过设置隔磁零件来改变磁场结构,使磁力线形成蜿蜒式走向而被引导到不隔磁径向流磁流变阀中未被利用的轴向阻尼间隙,从而增加磁流变阀中产生磁流变效应的工作区域,在不增大阀尺寸前提下实现增加液流通道有效阻尼长度的目的。采用有限元法对外形尺寸和液流通道结构完全相同的不隔磁和隔磁磁流变阀进行建模仿真分析,以观察磁流变阀隔磁和不隔磁结构对磁力线路径和磁感应强度分布规律的影响。同时在动态性能测试平台上对不隔磁和隔磁径向流磁流变阀压降及响应性能进行试验测试对比。仿真和试验结果均表明:隔磁径向流磁流变阀由于设置了隔磁零件,可使磁力线在轴向和径向阻尼间隙中均匀分布,使其压降比不隔磁磁流变阀的压降大。另外,由于轴向阻尼间隙受到磁场的作用,隔磁磁流变阀具有更大的上升响应时间。

Magnetorheological valve is one of the basic ways to apply and accommodate the MR fluid into most of hydraulic applications. A novel magnetic isolation radial MR valve which the magnetic flux was guided into the annular gap was proposed by changing the material properties of the typical single radial type MR valve. Compared with the magnetic field lines distributed only in the radial flow path of the non- magnetic radial MR valve, the magnetic isolation radial MR valve increased the effective annular region of the valve by changing magnetic field structure and without having to increase the valve dimension. The finite element method （FEM） was used to investigate the effects of magnetic field structure on pressure drop change in the non-magnetic and magnetic isolation radial MR valves under the same geometry conditions and the same flow path. The experimental test rig was set up to validate the simulation resuhs, the simulation and experimental results showed that the pressure drop of the magnetic isolation radial MR valve can be increased by changing the material properties to twist and weave the magnetic flux into unexposed region to the magnetic field, which was superior to that of non-magnetic radial MR valve. In addition, due to the annular flow path was affected MR valve had greater rise resoonse time. by the magnetic field, the magnetic isolation radial