Development of a Rotary Damper Integrated with Magnetorheological Bearings toward Extremely High Torque–Volume Ratio

Abstract

Magnetorheological (MR) technology has provided effective solutions to many engineering bottleneck problems due to its controllable nature. However, designing a rotary MR damper with a high torque–volume ratio is always challenging, especially for some specific application scenarios with constrained space, such as robot joints. To solve this problem, a rotary damper based on MR bearings was designed and evaluated in this study. In this rotary damper, two MR bearings are utilized to provide controllable damping torques and serve as rotors, which greatly saves space while providing high torque. This feature grants the characteristics of compact design and high torque–volume ratio. Quasistatic testing shows that the damping torque of this rotary damper can reach 2.92 Nm when the applied current is 1.2 A. It achieves a high torque–volume ratio of 190 kN/m2, which is nearly four times higher than that of existing rotary MR dampers. The experimental results show that the proposed MR damper is effective in satisfying the high torque requirement in a limited space.