A Novel Double Bevel Support Structure for Downhole Robot

Downhole robot is driven by friction force between the downhole robot and the borehole wall. The traction force $$=$$ friction coefficient * support force. The friction coefficient is generally ranging from 0.1 to 0.4, and the support force is usually small. So the traction force of the downhole robot has been subject to the objective conditions. In order to improve the traction force, in this paper, a novel downhole robot with double bevel self-locking structure (DBSS) is invented. The mechanical model of the DBSS is established. And the mathematical equations of mechanical model are deduced according to the mechanical model. Furthermore, the angle ranges of the bevels and the friction coefficient of each contact surface are obtained. Then, an experimental device of DBSS is designed and fabricated. And the experimental results show that the experimental data are basically the same as the theoretical calculation values. The proposed DBSS will have a great application prospect on downhole robot with large traction force. And the DBBS will reduce the damage produced by the friction block compared with the cam self-locking structure.