Mechanical operation, install bearing parts allows a certain degree of temperature when touching body shell by hand, should not feel hot to normal, instead it indicates that the temperature is too high.
Bearing high temperature causes are: lubricants quality does not meet the requirements, or degenerate, lubricant viscosity too high body assembled too tight (lack of clearance), plane bearing Assembly too tight; bearing washer on the shaft or casing rotation; load too large; or rolling bearing cage fragmentation.
Running allowed light in a plane bearing noise if the sound is too loud or unusual noise or impact sound, it indicates that the bearing is faulty.
Causes of noise of rolling bearings are more complex, and one is the inner and outer rings of bearing surface wear. Because of this wear, damage bearings, bearings and shaft with shell combined with led axis deviation from the correct location, noise resulting from the axis at high speed. When you are bearing fatigue, its surface metal flake, would also make abnormal noise of radial clearance of bearings increases. In addition, insufficient bearing lubrication, formation of dry friction and bearing broken produces abnormal noises. After bearing and wear loose, stay loose, damaged, will also have an abnormal sound.
 (1) the surface oxide layer
Steel surface subjected to instantaneous temperature and oxygen in the air, up into very thin (20~30nm) thin-layer iron oxides. Worthy of note is the thickness of the oxide layer and surface grinding of degenerating layer corresponds to the total thickness of test results is related. This indicates that the oxide layer thickness for grinding directly related, are important signs of grinding quality.
 (2) amorphous organization
Transient high temperature of grinding workpiece surface to melt when the molten metal flow is evenly coated on work surface and substrate metal cooling at an extremely fast rate, forming a very thin layer of amorphous organization. It has high hardness and toughness, but it only has about 10nm, easily removed in precision grinding.
 (3) high-temperature tempering
Transient high temperature can make the surface of the grinding area some depth (10~100nm) is tempered heating temperature by heating to above the workpiece. In the case of austenite temperature not reached, as the heated temperature increases, its surface layer-by-layer corresponds to the heating temperature of high temperature tempering or tempered microstructure transformation, hardness also declined. Higher heating temperature and decline in hardness and the more powerful.
 (4) two-layer of hardened layer
When a transient high temperature of grinding workpiece surface layer heated to a temperature of austenite (Ac1) above, of austenitic is the layer of tissue in the subsequent cooling process, and again quenched martensite organizations. Workpiece quenching Burns for a second time, the secondary hardening layer must be the hardness under extremely low temperature tempering.
 (5) the grinding crack
Secondary hardening burn the workpiece surface layer of stress changes. Quench zone for the second time in the compression state, below the maximum tensile stress exists for high-temperature tempering materials, here is where they are most likely crack the core. Crack most at austenite grain boundaries along the original transmission. Serious burns can cause the entire grinding surface cracks (crack) cause the workpiece end.
Manufacture of rolling bearings generally after forging, heat treatment, machining, grinding and assembling of the machining process. Justification, advanced processing technology, can also affect the stability of the bearing life. Which influence the quality of finished product bearing heat treatment and grinding processes, bearing failure and often have a more direct relationship. Research on bearing surface degenerating layer shows that in recent years, closely associated with the surface quality of bearing grinding process.
Main task of bearing service life analysis was based on the large amount of background material, analysis of data and failure modes, identify the main factors contributing to failure so that targeted measures for improvement, and extended bearing service, avoiding unexpected early failure in bearing.



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