Fundamental Design Theory Of Elastic Composite Cylindrical Roller Bearing And It’s Application

The cylindrical roller bearing is an important basic component of a machine. The higher complexity of modern mechanical equipments bring about the extreme working conditions, such as the high speed, the heavy load, the high precision and the continuous requirements of application. The traditional cylindrical roller bearing has its deficiencies in use, such as low transmission precision, high vibration noise, fragility under high speed and heavy load, etc. There is an urgent need of cylindrical roller bearings with excellent comprehensive properties. Funded by the project of National Natural Science Foundation and the project of Hunan Provincial Science and Technology, this dissertation suggests a new designing idea of elastic composite cylindrical roller bearings, and has invented it by studying the principles of structural components systematically. The basic theory of elastic composite cylindrical roller bearings has been established and a general method for the bearing structure design and manufacturing has been proposed.The main research works and contributions of this dissertation are as follows:(1) The elastic composite cylindrical roller bearing has been invented. Through the in-depth analysis of the structure components and the application of the solid cylindrical roller bearing and the hollow cylindrical roller bearing, the reasons of structure defects of solid and hollow cylindrical roller bearings were find out. Through innovative cylindrical roller structure, the dissertation puts forward creatively the design idea of elastic composite cylindrical roller bearings and the elastic composite cylindrical roller bearing has been invented. With the advantages of solid and hollow cylindrical roller bearings, the elastic composite cylindrical roller bearing improves the comprehensive performance of the cylindrical roller bearing and the disadvantages of cylindrical roller bearing are overcomed. Thus, the elastic composite cylindrical roller bearing is a breakthrough in the field of bearing structure innovation.(2) The theory about the basic characteristics of elastic composite cylindrical roller bearing is established. The concept of the composite cylindrical roller bearing is first put forward by the author, so the related theory is still absent. For this reason, this dissertation proposes several new concepts of the elastic composite cylindrical roller bearing and gives a complete definition about its physical significance for the first time. Based on the maximum shear stress strength and the contact strength theory, the principles of elastic composite cylindrical roller bearings are established. By using the finite element analysis, the advantage of the elastic composite cylindrical roller bearing contact characteristics is proved. It can be conclude from the analysis results that the bending fatigue life of the elastic composite cylindrical roller bearing is longer than that of hollow cylindrical roller and deep hole of the hollow cylindrical roller. By analyzing the axial stress distribution along the contact area of the elastic composite cylindrical roller bearing, the dissertation shows that the reasonable design structure of deep hole can eliminate or reduce "edge effect" of the elastic composite cylindrical roller bearing. The research works of this dissertation also show that the degree of filling and deep hole size parameters is the important parameters of the structure of the elastic composite cylindrical roller bearing, which provides a theoretical basis for the elastic composite cylindrical roller bearing structure design.(3) The general method of elastic composite cylindrical roller bearing structure design has been proposed. Based on the theory of basic characteristics of elastic composite cylindrical roller bearings, the rolling body filling degree KT, rolling body deep hole edge size parameter α、C are selected as the basic design parameters of elastic composite cylindrical roller bearing structure. The optimal filling degree and deep hole edge size values of elastic composite cylindrical roller bearing are obtained in two different conditions.(4) The manufacturing process of elastic composite cylindrical roller with the trial of the first batch of it is designed. The manufacturing processing difficulties, such as the coaxial hole and deep hole, the material filling of it are overcomed. The rolling body detection tool for measuring the size of deep hole has been invented. The prototype of the elastic composite cylindrical roller bearing has been completed, which provides the basis for engineering and related test.(5) The stiffness analysis model of the composite elastic cylindrical roller bearing has been established. The static radial stiffness calculation model for the elastic composite cylindrical roller bearings with and without preload has also been established. Two bearing stiffness testing experiments are designed, and the static radial bearing stiffness of the elastic composite cylindrical roller bearings with and without the preload have been measured. The measured static radial bearing stiffness values are compared with the calculation values to verify the correctness of the two bearing static radial stiffness calculation model.(6) The function of the elastic composite cylindrical roller bearing is preliminary studied with the application to the printing machine roller bearing. Research results shows that by using the elastic composite cylindrical roller bearing with pre-loading as the bearing parts of the printing cylinder, the printing roller bending deformation and the printing roller bearing performance can be improved effectively.The theoretical and experimental research in this dissertation verified the design feasibility of elastic composite cylindrical roller bearings, providing a fundation for the further study and application of this new bearing.