Performance enhancement of a rotary magnetorheological damper induced by needle roller structure

In order to improve the mechanical performances of magnetorheological (MR) damper, a rotary MR damper with needle rollers was proposed based on squeeze mode. The MR fluid was induced to work in a special mode by inserting the needle roller structure, thus the output damping torque of the damper was significantly improved. The experimental results show that the damping torque shows a trend from stable to increased when the angular velocity of the damper is low, and the maximum damping torque increases with the increase of the excitation current due to the insertion of the needle roller structure, which is exactly consistent with "Stribeck effect". Finally, this interesting phenomenon was analyzed and summarized.