Study On The Influence Of Structure And Axis Misalignment On The Performance Of Rotating Tail Pipe Hanger Bearings

With the continuous improvement of our country's oil and gas exploration technology,the performance requirements for cementing equipment such as rotary tail pipe hangers are constantly improving.Our country's self-developed rotary tail pipe hanger bearings are mostly thrust tapered roller bearings.In actual working process,the performance of this type of bearing is limited by the working space in the underground and its structural parameters.At the same time,the installation and manufacturing misalignment in the axial position will have a further impact on the service life of this type of bearing.In this paper,the above phenomena are studied.Taking a self-developed tail pipe hanger bearing as the object,the influence of structural of the bearing and axis misalignment on the performance of this bearing is discussed.The main research contents of this paper are as follows:(1)The relationship between structural parameters and performance of the rotating tail pipe hanger bearing is studied.The relationship between the number of rollers bearings and the structural dimensions of the bearing components are derived,and the influence of the number of rollers on the capacity of the bearing is obtained.Based on the influence law,combined with the constraints of bearing capacity and component size,the structural parameters of the bearing are improved.(2)The load distribution and cyclic variation on the key components of the bearing under axial misalignment are studied.The reason for the axial error of the rotary tail pipe hanger bearing is analyzed.Based on the modified load-deformation relationship,an analytical model for the roller load distribution of the bearing under Axis center misalignment is established.The influence of the Axis center misalignment on the rollers' load distribution are obtained.Based on the kinematics principle of rolling bearing,combined with the load distribution,the change of the load sequence on the key components of the bearing is analyzed,and the variation of the load sequence cycle on the bearing rings and roller under the Axis center misalignment are obtained.(3)The variation of bearing key components' stress distribution under axial misalignment are studied.The calculation method of the initial contact gap of the improved logarithmic modification roller is deduced.The contact stress analysis model of the bearing under the Axis center misalignment is established based on the non-Hertz contact theory,and the finite element method is used to verify the axial error.The change of contact stress of roller and the equivalent stress of the roller-to-ring contact are obtained under the Axis center misalignment.(4)The variation of bearing's fatigue life under axial misalignment was investigated.Considering the influence of rollers' fatigue life and contact stress on bearing's life,the L-P fatigue life model is improved.Through the analysis results of the bearing load and stress obtained above,the fatigue life of the bearing under different Axis center misalignment are calculated,and the influence of the Axis center misalignment on the bearing life is obtained.In this paper,the influence of structure and axial misalignment on the performance of the rotating tail pipe hanger is discussed.The results obtained from the research and analysis can provide theoretical basis for the structural optimization and experimental research of this bearing.