Structure Design And Optimization Of Rotary Drive For A Rotary Drilling Rig

Rotary drive system is the most important part of the rotary drilling rig. The performance of rotary drive system can directly impact on rotary drilling rig working efficiency. Domestic factories start their manufacture later than foreign company, so they are lack of manufactural experience and experimental research. All these lead to frequent failure or low reliability of rotary drive. Therefore, the paper researches design theory of rotary drive, optimizes its weak spots, increases its reliability. It has important value to improve the efficiency of rotary drilling rig.The paper analyzes rotary drive system structure composition, function, working principle firstly, then compares the current domestic and foreign mechanical structure of rotary drive and finds out gap between different products, provides theoretical reference for domestic rotary drive design. And designs the rotary drive of XR220 D rotary drilling rig, then builds models of rotary drive box, gear and driving part by three-dimensional software Creo. On this basis, analyzes finite element of key components in order to understand its stress and displacement distribution situation, finds out the weak spot of structure, last provides theoretical basis for rotary drive optimization design. The finite element analysis results show that the maximum stress value in rotary drive box and driving part is greater than allowable stress of its material. These parts are easily destroyed at extreme working conditions, so they are weak spots of rotary drive. Modal analysis on rotated key components of rotary drive obtains previous six natural frequencies. The simulating results indicate: there is no resonance on rotary drive. Finally, the paper optimizes design weak structure in rotary drive, analyzes finite element of optimized structure, compares stress before and after optimizing. The optimization result shows that the maximum stress value of rotary drive box and driving part significantly decreased and are smaller than allowable stress, the result prove the rationality of optimizing structure.