Research On Bearing Structure Optimization And Roller Generatrix Modification Of Rotating Tailpipe Hanger

With the extensive application of liner cementing technology,the performance requirements of rotating liner hanger and other cementing equipment are constantly increasing.Most of the bearings of the rotary stern tube hanger independently developed in China are thrust tapered roller bearings.In the actual working process,the performance of this type of bearing is restricted by the underground working space and the structure size of its own components.The main method of improving the bearing is to optimize the bearing performance by improving the size of the bearing element.The other main method is to modify the design of the roller so that the stress is evenly distributed along the axial direction on the roller-raceway contact surface to reduce Maximum contact stress value to avoid or reduce "edge effect" to improve bearing life.In this paper,the research on the above phenomena is carried out.Taking an independently developed tail pipe hanger bearing as the object,the influence of the structure and the modification method of the roller bus bar on the performance of this type of bearing is discussed.The main research contents of this article are as follows:(1)Based on non-dominated sorting genetic algorithm,multi-objective optimization design is performed on the structural parameters of the rotating tail pipe hanger bearing.Taking the number of rollers as the design variable,the bearing capacity,fatigue life and wear life of the bearing are the optimization goals.On the premise of not changing the overall structure of the bearing,after considering the comprehensive working conditions,the dimensional parameters of the bearing element have been improved.(2)The load-deformation fitting formula with the generatrix modification parameters of the bearing roller of the rotating tail pipe hanger is proposed.Firstly,based on the non-Hertz contact theory,the contact stress and contact deformation analysis model of the rotating tailpipe hanger bearing was established by Matlab;secondly,the model was verified by finite element simulation;and finally,the data processing was performed by using a multiple linear regression fitting function,Modify the load-deformation empirical formula of the logarithmic generatrix modification curve and the asymmetric logarithmic generatrix modification curve of the bearing roller.(3)Based on genetic algorithm,the shape modification of roller generatrix is studied.The logarithmic generatrix repair of the bearing roller of the rotating tail pipe hanger was carried out.The analysis found that the contact stress at the small end of the roller was greater than the contact stress at the large end,resulting in the failure of the small end before the big end.In view of this situation,the asymmetric logarithmic generatrix modification parameters are introduced to reduce the contact stress difference between the two ends of the roller,making the contact stress distribution more uniform,and using the variance of the contact stress along the generatrix as the objective function,the genetic algorithm is used to modify the asymmetric generatrix The shape parameters are optimized to obtain the optimal asymmetric logarithmic modification curve.This paper discusses the effect of bearing structure on the performance of tapered roller bearings,puts forward load-deformation fitting formulas for roller generatrix modification parameters,and optimizes the roller asymmetric generatrix modification.