Improved Design and Analysis of the Flexible Screw Mechanism for a Worm Robot

In the previous study, we proposed a new type of flexible screw mechanism using a roller to decrease the friction. And the pipe-in robot with this mechanism can complete curved shapes motion was tested. However, this mechanism generates large lateral deflection during curved shape movement which cause low drive efficiency. By modifying the drive shaft of this mechanism, it can complete curved shapes motion with less lateral deflection than the single spring shaft. In this paper, we analyzed and tested the improved design of the shaft compared with the single spring shaft. From the experimental results, the lateral deflection of the shaft is reduced and the transmission efficiency is enhanced.