Research On Fatigue Life Of Gear Transmission Of Drilling Rig Rotary Table Method Using Load Spectrum

The fatigue life of rig rotary table gear is one of the important indexes to evaluate the overall performance of drills. The rotary table usually works in complicated environment, under the circumstance of unknown impact and overload, so it becomes quite important to forecast and calculate its life. Traditional fatigue life's studying usually adopts comprehensive fatigue test-bed or physical prototype to do some destructive trials, which needs more time, more cost and cannot forecast the fatigue life at the design stage. The study on the dynamic characteristics, especially the fatigue properties of domestic rotary table is very significant to improve its comprehensive performance and international competition.Choosing the domestic biggest ZP495 rotary table as the object, this thesis used the joint simulation technology to get the rotary's fatigue life under typical working conditions. The main research included the following content:The 3d model of the drill rig rotary table drive system had been set up by Pro/E. Based on the dynamic analysis software ADAMS, the meshing force of the rotary bevel gear under typical conditions was obtained, and the numerical dynamic simulation of the rotary bevel gear was realized. The varying characteristic of the force provided an accurate data support for the rotary drive system controlling and the fatigue analysis of bevel gear.The fatigue statistics method for dealing with simulation load was studied. Using the principle of the rain flow count, the load classification, cumulative frequency and counting of cyclic number of the simulation load were accomplished. The load matrix table and rain flow statistic histogram were also got by the same way. Using a simple way described the virtual simulation load.The bending stress distribution of the bevel gear was obtained by the FEA under the simplified model. The risk area of bending fatigue can be determined from the stress distribution. Based on the nominal stress method, combined with the simulation load, FEA results and the material fatigue properties, the life of the bevel gear was calculated in the fatigue analysis software Designlife. This thesis realized the fatigue life prediction of the rotary table bevel gear. The analysis and results can provide some reference values for the optimization design, life prediction and the follow-up maintenance of the rotary bevel gear.