SKF bearing installed correctly and the main effect of life

Before installation considerations SKF bearing preparation by SKF bearing antirust processing and packaging, so do not open the packing before installation. In addition, SKF bearing on coating of rust-proof oil has good lubrication performance, SKF bearing for general purpose or filling grease SKF bearing, can not directly use cleaning. But for the instrument with SKF bearing or SKF bearing for high-speed rotation, the application of clean cleaning oil washed away anti-rust oil, SKF bearing is easy to rust at this moment, not for a long time. Shaft and the shell inspection, cleaning, SKF bearing and the shell, confirm no scar or mechanical processing of burr. Shell has absolutely can not have abrasives ( SiC and Al2O3, etc. ) Sand, scraps, etc. Next inspection shaft and shell size, shape and machining quality are consistent with those drawings. SKF bearing before installation, in the inspection of the shaft and the shell of the mating surface coating machine oil. SKF bearing installation method SKF bearing installation method for SKF bearing type and matching conditions are different. Due to the more commonly as the axis of rotation, so the inner ring and outer ring can respectively USES the interference fit and clearance fit, the outer ring rotates, the outer ring USES the interference fit. ( 1) Installed pumped into general use press, also can use a bolt and nut, when forced to use hammer into the pack. ( 2) Heat will install SKF bearing in oil heating makes its expansion installed on the shaft after heat method can avoid the unnecessary force the SKF bearing, in a short time to complete installation work. Material factors affecting the service life of SKF bearing rolling early failure forms of SKF bearing, mainly has broken, plastic deformation, wear, corrosion and fatigue, is mainly contact fatigue under normal conditions. SKF bearing failure in addition to the service condition of the parts, mainly by the steel hardness, strength, toughness, wear resistance, corrosion resistance and internal stress state. The main internal factors affecting these properties and the state has the following several. Quenching martensite in the steel quenching of retained austenite in the steel quenching steel not dissolved carbon impurity content of the residual stress of steel after quenching tempering in order to make the material factors affecting SKF bearing life at its best, you will first need to control of the original organization before quenching steel, can take technical measures are: high temperature ( 1050℃） Austenitizing rapid cooling to 630 ℃ isothermal normalizing get false eutectoid pearlitic structure, or cold to 420 ℃ isothermal treatment, obtain bainite structure. Also can use forged heat rapid annealing, obtain fine granular pearlite structure, to ensure that the carbide steel small and uniform distribution. This state of the original organization when austenitizing quench heating, in addition to into the austenite carbides, not soluble will gather into fine granular carbides. When the original organization must be in the steel, the carbon content of quenched martensite ( The austenite after quenching heating carbon content) , residual austenite and the body not dissolve carbide mainly depends on the amount of quenching heating temperature and holding time, as the quenching heating temperature increased, A certain time) The decrease in the number of, not soluble in steel carbide ( Quenching martensite increased carbon content) , increasing number of retained austenite, hardness first increases with the increasing of quenching temperature, peak and decreased and then increased with the temperature. When quenching heating temperature must, as the extension of austenitizing time, did not dissolve carbide to reduce the number of retained austenite, hardness is higher, for a long time, to slow this trend. When the original organization of fine carbide hours, because the carbide is easy to dissolve in austenite, thus make the hardness after quenching peaks move to low temperature and occur in a relatively short austenitizing time. To sum up, GCrl5 steel after quenching not dissolve carbide at about 7%, the residual austenite is around 9%, About 55%) As the best organizations. And, when the original organization of carbide small, uniform distribution, the reliable control of the above levels of the microstructure, to obtain high comprehensive mechanical properties, which has high service life. It should be pointed out, has the fine carbide dispersion distribution of the original tissue, quenching heat insulation, not dissolve tiny carbides would gather to grow up, make its coarsening. Therefore, for with the original organization SKF bearing parts quenching heating time shoulds not be too long, the rapid heating austenitizing quenching process, will can obtain higher comprehensive mechanical properties. In order to make the SKF bearing parts quenching tempering after large surface residual compressive stress, could pass infiltration during quenching heating carbon or nitriding atmosphere, on the surface carburizing or nitriding for a short period of time. Because the steel quenching when heated austenitic actual carbon content is not high, far lower than on the phase diagram shows the equilibrium concentration, so it can absorb carbon ( Or nitrogen) 。 When austenite contains higher carbon or nitrogen, the Ms is reduced, quenching surface when the martensitic transformation in the aftermath of the inner layer and center, produce the large residual compression stress. GCrl5 steel by carburizing atmosphere and the atmosphere carburizing quenching ( Both low temperature tempering) After treatment, the contact fatigue test, you can see that the surface carburizing of life than carburized increased 1. 5 times. The reason for carburizing of the surface of the parts has a larger residual compressive stress.