Analysis And Improvement Studying Of Middle-mast And Pulley-yoke Failure Of Rotary Drilling Rig

Rotary drilling rig is a multi-function, high efficiency and less pollution into the pile hole equipment. As rotary drilling rig's key part, the mast is to provide drill-oriented campaign, position adjustments, and power transmission. The mast is bearing the loads when drilling; pulley yoke is to guide wire rope of the main and auxiliary winch. The pulley yoke is weighty, but installed at the highest position. The power drive drives the kelly bar, but it only has one buffer device. Therefore, it is essential to failure analysis and improvement for the key parts.First, this paper introduced the current status of rotary drilling rig, studied the key parts, educed the mast fracture reasons, the pulley-mechanical model and the damage causes of power drive. Then started with the finite element method, used 3D graphics software Pro/E and finite element analysis software Ansys modeling and analyzing respectively in the mast and pulley yoke, obtained stress distribution of danger zone of the couple of moments and pulley yoke in the pull, verified the accuracy of the mechanical analysis. Then put forward measures for improving the mast and pulley-weight loss programs, and analysed again to prove that the improvement is effective. At last, we concluded the existing shockproof machine, proposed design programs of secondary buffer devices and the reduction pin, which raised the capacity of power drive.