Design and Development of Compact Magnetorheological Fluid Clutch (CMRFC) with Multi-layered Disks and Micro-sized Gaps

There is a strong demand for a human-machine-coexistent machine, e.g. a power-assist system or a computer-aided rehabilitation system, in the context of the super-aging society. In such a human-machine-coexistent system, it is important to guarantee hardware-level safety by utilizing human-friendly actuators. In this paper, we developed two types of compact MR fluid clutches (CMRFC) for human-friendly actuators, which performs about 5Nm torque by applying 1A current and have two different gap-size (50 mm and 100 mm). We tested their static torque. First, we used a conventional MR fluid as a working material of the CMRFCs. Then we used new MRF, which consist of nano-sized (104 nm) Fe particles. According to the experimental results, gap-size affects not only magnetic property but also easiness of filling of MRF (or particles).