Abstract: In order to solve the problem of locomotion interference for the roller pipe-robot when getting across a bend pipe, reduce the abrasion because of sliding frication and improve the service life of this kind of robots, a drive technology of roller pipe-robot with self-adaptive ability which is named triaxial differential drive technology is presented. After theoretical analysis on motion relation and torque transmission relation between parts of pipe-robot’s internal transmission system and in-depth research on internal power flow direction, mathematical models of torque transmission relation are established, the theoretical formula of transmission efficiency is deduced, and the high drive efficiency and big power to volume ratio of this drive technology are proved .

Key words: Equations of torque transmission, Pipe-robot, Power flow, Transmission efficiency, Triaxial differential technology