Influence of friction force on seal mechanism with one degree of freedom

This paper deals with the influence of a friction force on a small mobile device, seal mechanism with a 1-degree of freedom (DOF). This device has a piezoelectric actuator, electromagnet CA that applies a constant friction force and electromagnet CB controlled. The friction at electromagnets CB is alternated by on-off control. The whole device wriggles with electromagnets CA while the piezoelectric actuator extends and contracts. The 1-DOF device can move up to micrometer steps. The movable range is infinite in principle. Seal mechanism has the same structure as the inchworm mechanism. However, seal mechanism has a smaller number of controlled actuators and is driven by a smaller number of steps than the inchworm mechanism. In this paper, as the preliminary experiment for the cooperation of several seal mechanisms, the moving performance on the slope from 0 to 90 degrees was investigated. Moreover, the relationship between the friction force and the displacement on a vertical plane was investigated experimentally. Under a set of sufficient friction forces, this device was possible to move even on the vertical plane. The load capacity of this device was also investigated. From the results, friction force in this device restricted the load capacity. Finally, its load capacity was compared with an inchworm device. The lower friction force to hold each device restricted its displacement.