Design of driving unit for horizontal well traction robot

The driving unit is the key structure of the horizontal well traction robot(HWTR),which directly determines the outer diameter and the traction force of the HWTR.To enhance the traction force and reduce the outer diameter,a modularization approach was employed in the design of driving unit of the HWTR.The appropriate number of the units were decided according to the strength of traction force.The optimization of the key parameters of the force adjustment structure was carried out for oil pipes with an inner diameter of 5 in,7 in and 9 in respectively.The relationship between the structure parameter and the spring force was established.Two feasible schemes for the traction force adjustment structure were presented.It is proved that the modularization approach could enhance the traction force of the HWTR.