Abstract
In-pipe mobile micromachines have many applications including micro maintenance robots for nuclear reactors and are expected to be realized in the near future. For practical micromachines, the authors have proposed the bellows microactuator using fluid power with high power density. In this paper, an inchworm type in-pipe mobile micromachine which is traversable branched pipes using the bellows microactuators is fabricated and the performance is examined. Firstly, performance of displacement magnification mechanisms significant for micromachines is theoretically investigated and the effectiveness of a pulley type mechanism is proved. Secondly, for structure of an in-pipe mobile micromachine, a bending and propelling mechanism with 1-bending DOF using pulley type mechanisms is proposed and the traveling sequence in branched pipes is theoretically investigated. Finally, an in-pipe mobile machine with 25mm in diameter is fabricated and the traveling experiments are conducted. It is clarified that the traveling velocity in a straight pipe is increased and the fabricated machine is able to traverse a Y-shaped pipe.
