Development of a variable-damping magnetorheological damper with multiple poles

The study aims to deal with a suspension system whose main function is to isolate and absorb the impact from road surface to vehicle body. To provide good riding comfort, a damper with variable and wide-range damping is highly essential. In this study a magnetorheological (MR) damper with multiple poles is developed. This new designed variable-damping damper is totally different from those conventional constant-damping hydraulic dampers, and even different from common single-pole MR dampers. The range of damping force for this new MR damper is also effectively extended. Simulation of magnetic flux and field has been done in the study to provide an optimal structure of the damper which significantly enhances the damping force while avoiding magnetic saturation. After the dynamic test for the MR damper, experimental results show that the provided damping force can be significantly increased with the increase of input current from low to high speeds. Damping force can be varied by 7.41 times. It proves that this new MR damper with high damping force can be controlled adaptively at wide range of operation conditions. It is suitable to be an adaptively variable damping source in semi-active suspension systems or other applications.