Design And Analysis Of Liquid Friction Bearing For MCCR Mills

The technology of thin slab endless continuous casting and rolling has the advantages of compact technological process,low investment cost,low energy consumption and high product quality.But with the development of hot strip rolling technology,the existing liquid friction bearing technology can not meet the requirements of thin slab endless continuous casting and rolling process,bearing are often damaged in the use,which resulting in lower production efficiency and increased cost.Based on the MCCR project of Shougang Jingtang Company,in order to design liquid friction bearings which can satisfy the technology of thin slab endless continuous casting and rolling,the following aspects would be studied in this paper:The lubrication theory of rolling mill liquid friction bearing is studied and the bearing capacity is calculated..The working principle of hydrodynamic fluid friction bearing is based on the principle of lubrication wedge pressurization;and the hydrostatic-hydrodynamic fluid friction bearing is to add high pressure oil chamber to balance external load on the basis of hydrodynamic liquid friction bearing,and to improve bearing capacity under low speed and heavy load.Through the technical parameters of the MCCR rolling mill,the specifications of liquid friction bearings can be determined,and the relationship between bearing speed and capacity can be calculated.Thus the bearing capacity curve can be drawn,and the bearing can be determined to meet the rolling process requirements of the mill.The liquid friction bearing is designed after the specification is determined..The liquid friction bearing of MCCR mill consists of four parts: radial load bearing assembly,axial load bearing assembly,quick assembly & disassembly device and sealing system.By adjusting the chemical composition of Babbitt,the friction reducing material of bearing is obtained.The existing Babbitt can not meet the requirement of MCCR rolling process.Four different types of Babbitt are obtained by adjusting the chemical composition and adding appropriate alloying elements such as Ni,Ag,Cr and Ti.By testing the bonding strength and high temperature creep properties,observing the microstructure,and testing the surface hardness of the four new types of Babbitt alloys,the most suitable one can be selected.The bearing characteristics is analysed by the finite element method.Firstly,I set up the model of bearing and set the boundary conditions.Then the oil film are analyzed and compared under the conditions dynamic pressure lubrication and hydrostatic-hydrodynamic pressure lubrication conditions to verify the performance· of the bearing.