Mechanical Analysis And Ceramic Material Research Of Silicon Carbonitride High-speed Ceramic Ball Bearing Based On Finite Element Method

Bearings,gears and hydraulic system are the three main elements of mechanism components,and different combinations can be made into a variety of mechanical equipment.The development of bearing determines the industrialization level of a country,and its performance depends on four aspects:design,material,lubrication and processing technology.High-speed bearing will produce great centrifugal force and produce a large amount of friction heat,which will lead to bearing failure.Currently,ceramic materials are usually used to prepare rolling element to improve the performance of bearing in terms of materials and lubrication.Ceramic ball bearings have great application prospect in high speed,high temperature,corrosion and other special working conditions,but toughness of ceramic material is poor,and impact resistance of ceramic bearing is insufficient.Therefore,ceramic ball bearings are limited in ship,blasting and other occasions where the impact resistance is required.In this paper,silicon carbonitride ceramic material was prepared,and their properties were tested and studied.This kind of material was used to improve the toughness and impact resistance of bearings.The mechanical analysis of silicon carbonitride ceramic ball bearing is carried out by using finite element analysis software ANSYS.The main research contents included:?1?The motion characteristics of bearing were explored and the theoretical formula were derived to study the internal load distribution,the distribution of stress,strain,speed and acceleration of bearing under static load.The fatigue failure mode of bearing was studied in order to provide theoretical basis for the modification of bearing material.?2?The silicon carbonitride?-Si₃(C_x,N_1-x)₄ was prepared by self-propagating synthesis and hot pressed sintering,researching about the carbon solubility in the mixture,the influence of carbon concentration on the material structure stability,mechanical properties and tribological performance.It was concluded that the solubility of carbon in the solid solution was about 10 wt.%,and the phase segregation was emerged to form the Si₃N₄/SiC composite when the solubility of carbon was above 10 wt.%.Within the scope of the solid solution state,the fracture toughness and the abrasion resistance of?-Si₃(C_x,N_1-x)₄ both increased with increasing of carbon concentration.However,when the material transferred from solid solution into composite material,the fracture toughness and anti-wear performance decreased with increasing of the concentration of carbon,which was mainly caused by the interfacial defects in compound.If this material was used as a bearing roller,it can improve the toughness and enhance the impact resistance of the bearing.?3?The statics analysis of silicon carbonitride ceramic ball bearing 6100 was studied based on ANSYS,found that the maximum stress existed in the contact surface between bottom rolling element and raceway,and inner ring had the maximum strain.With the increase of radial force,the contact stress and deformation displacement between rolling element and inner and outer ring both increased,and the contact stress between rolling element and inner ring was always greater than the contact stress between rolling element and outer ring.Compared with the maximum stress values of silicon nitride bearing and silicon carbonitride bearing,it was found that the mechanical properties of silicon carbonitride bearing were better and the stress was smaller.The feasibility of finite element method was verified by comparing with Hertz stress.?4?The dynamic analysis of silicon carbonitride ceramic ball bearing 6213 was studied based on Workbench.As the bearing had large centrifugal force in high speed,the contact stress between rolling element and outer ring was biggest.Comparatively,the contact stress between rolling element and cage was unstable.By comparing and analyzing the variation of stress between silicon nitride bearing and silicon carbonitride bearing,it is found that the stress value of silicon carbonitride bearing was small,but the difference between them became smaller with the stable operation of the bearing.The velocity of the rolling body showed periodic fluctuation,which reached peak when contacting with inner ring,and the velocity was 0 when contacting with the outer ring.The acceleration fluctuated greatly when the bearing was just starting,indicating that the vibration of the bearing was obvious at this time,but the acceleration tended to 0 after a certain period of operation.Through the modal analysis of the bearing,we found that there was no resonate in low frequency phase,but cage was prone to deform as stamping part,which needed to be optimized in process design and material selection.