Rolling element damage
　　When SKF bearings rolling element damage, such as peeling, cracking, pitting, through inner or outer ring raceway surface defect parts will produce vibration and shock.
　　When there is no radial clearance of rolling bearings, will have a frequency of nZfb (n=1,2, ... ) Impact vibration.
　　Usually has a radial clearance of rolling bearings, therefore, as is the case with the inner ring when there are pitting, under parts of pitting impact contact with the inner or outer ring in different locations, amplitude modulation can also occur, however at this time the orbital frequency FC is rolling for amplitude modulation. Vibration frequency for nzfb FC.
　　The so-called precision diagnosis method of rolling bearing, is in the use of simple diagnostic method after determining the SKF bearing has failed, determine the category of failure and further parts, so as to take appropriate countermeasures.
　　Precise diagnosis of rolling bearings and the like, reciprocating machinery, precision diagnosis of rotating machinery, mainly using spectrum analysis method. Because of rolling bearing vibration frequency is very rich, with both a low-frequency components, and high-frequency component, and each specific fault corresponds to a specific frequency. Spectral analysis is required before the adoption of appropriate specific frequency components of the signal processing method of separating and then absolute, final frequency analysis, to identify the characteristic frequency of the signal to determine fault location and category.
　　Bearing inner Raceway damage
　　SKF bearing inner Raceway of a injury-time, such as: flaking, cracking, pitting and other, if when you scroll the axis No radial clearance, will have a frequency of nZfi (n=1,2, ... ) Impact vibration.
　　Rolling element damage vibration conditions
　　Eccentric bearings
　　When the rolling bearing inner rings appear badly worn when bearing eccentric behavior occurs, when the shaft rotates, the axis (Center) will swing around the outer ring Center, in which case the vibration frequency of NF r (n=1, 2, ... ）。
　　Rolling road damage in vibration characteristics
　　Usually rolling bearing radial clearance, and unilateral loads, based on pitting some of the rolling impact meeting location different, cyclical change in vibration amplitude, amplitude modulation occurs. To rotate the frequency f, amplitude modulation, vibration frequency of nZfi FR (n=1,2 ... ); Rolling revolution frequency (the cage rotation frequency) FC amplitude modulation, oscillation frequency of nZfi ± FC (n=1,2, ... ）。
　　Injury of bearing Raceway
When you have an injury when the SKF bearing Raceway, such as peeling, cracking, pitting (as shown in Figure 2), will also have an impact vibration when rolling through. Due to the location and direction of loads of pitting is the relative position of a certain amount of, so at this point there is no amplitude modulation, vibration frequency is nZfo (n=1,2, ... ）。