Research On Dynamic Characteristics Of Oil Lubricated Corrugated Foil Bearing-Rotor System

With the increasing speed of rotating machinery,higher requirements are put forward for the rotor support system.Due to the structure and material properties of the foil,the foil bearing has better elastic support performance and a certain degree of automatic adjustment.Compared with the general sliding bearing,it has strong environmental protection ability and excellent dynamic performance under high-speed operation.It is more and more widely used in highspeed rotor systems.At present,most scholars at home and abroad focus on gas lubrication in researches on foil bearings.Research on oil-lubricated foil bearings is rare.Compared with gas lubrication,oil lubrication is more suitable for high-speed and heavy-duty working environments.To meet the needs of the working environment of oil-lubricated bearings,this paper proposes a corrugated foil bearing that uses lubricating oil as the lubricating medium.The bearing is supported by a combination of four-leaf flat foil and four-leaf corrugated foil,which combines the structure of a blade-type foil bearing and a corrugated foil-type foil bearing.It has the advantages of convenient disassembly and assembly,simple maintenance and high bearing capacity.Research on the dynamic characteristics of the corrugated foil bearing-rotor system with high-speed lubricating oil as the medium has been carried out.In this paper,a four-leaf structure type wave foil bearing is designed,the structural parameters of its bearing,foil,bearing seat and other components are determined,65 Mn is selected to prepare the foil,the foil processing technology is formulated,and the oil lubricated wave foil is completed.Preparation of bearings.The combined load deformation model of flat foil and corrugated foil is established,and the relationship between the load of the supporting foil and the deformation of the foil is calculated.The finite element model of the corrugated foil bearing-rotor system is established,and the dynamic characteristics of the rotor such as Campbell diagram,modal shape,and critical speed are obtained.The relationship between the support stiffness and damping of the corrugated foil bearing and the dynamic characteristics of the rotor system is studied.The corrugated foil bearing-high-speed rotor experiment platform was built,and the dynamic experimental research was carried out on the rigid multi-oil wedge sliding bearing and corrugated foil bearing,and the vibration waveform,axis trajectory,frequency spectrum and other system dynamic characteristics of the bearing-rotor system were obtained.curve.The comparative analysis of the experimental results of rigid multi-oil wedge sliding bearings and corrugated foil bearings shows that the rotor supported by corrugated foil bearings can stably pass its own critical speed and keep the amplitude at a low value during the speed-up process;The plate bearing support can effectively suppress the dynamic instability of the rotor’s oil film turbulence and the resulting oil film oscillation during high-speed operation,so that the highspeed rotor system can operate stably.The experiment compares the supporting performance of foil bearings with different axial lengths and forming processes.The experimental results show that the axial length of the foil and the forming process have a direct effect on the supporting performance of the bearing.The longer the axial length of the foil and the forming rigidity The larger foil forming process helps to improve the supporting performance of the corrugated foil bearing.This article lays a theoretical and experimental basis for the practical application of oil-lubricated corrugated foil bearings.