Design and experimental evaluation of a multidisk magnetorheological fluid actuator

A new multidisk magnetorheological fluid actuator was proposed using the shear stress of magnetorheological fluid between rotating disks. The transmission torque was calculated based on the Bingham model, and the magnetic circuit was designed in accordance with electromagnetic theory. Then, a magnetostatic simulation was conducted to validate the designed magnetic circuit. Furthermore, an experimental study was performed to investigate the performance of the prototype. The results show that the transmission torque increases approximately linearly with the input current within the saturation range of magnetorheological fluid. Both the input current and the gap thickness have little influence on the dynamic response property of the proposed magnetorheological fluid actuator. Moreover, the temperature of magnetorheological fluid increases linearly with the time in the slip and loaded states, and the greater the slip power is, the faster the temperature rises. Furthermore, the temperature rise of magnetorheological fluid will result in the reductions of the torque transmission ability and the dynamic response speed. On the whole, the proposed multidisk magnetorheological fluid actuator has a higher torque capacity and a slightly slower dynamic response in comparison with the present magnetorheological devices. It is promising for applications in many high torque occasions.