Bearing diagnosis analysis technology to help enterprises to avoid accident - bearing knowledge

Rolling bearing is most widely used in all kinds of rotating machinery of a mechanical components, is also one of the most easily damaged components. Many of the rotating machinery fault associated with rolling bearing, the working performance of the rolling bearing is good or not will directly affect the work of the whole machine performance. According to statistics, in the use of roller bearing of rotating machinery, due to rolling bearing damage failure accounted for about 30%. Therefore, the rolling bearing working condition monitoring and fault diagnosis technology research more and more get people's attention. There are more specifically for rolling bearing fault diagnosis technologies, such as CSl ( 爱默生) Peakvue Entek ( RockwelAutomation) The gses, SKF ESP ( The envelope) And so on, are relatively effective detection means. Peakvue technology principle Peakvue is Emerson's patented technology ( The United States patent no. : 689553) Peakvue is captured in a given time interval peak vibration signal analysis method of time domain waveform. When there is a metal friction or collision between can produce stress wave. Early fatigue spalling, gear and bearing defects, friction and wear and has stress wave and impact, and so on. Advanced patent technology Peak Vue is collecting and monitoring the transient stress wave, obtain the Peak value of stress wave and its frequency, and converted into frequency spectrum is analyzed. For the average sampling process, sampling interval is determined by analysis of bandwidth, usually follow the sampling theorem. For the vast majority of the analyzer or data collector for the time ( 2. 56 X imax) The inverse of. However, Peak Vue used high-speed sampling technology, signal after a high-pass filter to the number of sampling points per second fixed to 100000. Then on the peak, Waveform) Sampling and processing, get the Peakvue waveform and spectrum. Peakvue technology advantages compared with other diagnostic techniques, such as modem Peak Vue technology has the following advantages 1) Peakvue of real reflects the impact of the equipment, the time domain waveform in time domain waveform amplitude can judge the fault severity of 2) Tracking Peakvue trend can accurately judge whether the fault of the equipment is serious, when to maintenance; 3) Peakvue technology is not limited to intermediate frequency range, it can be used to detect high speed and low speed ( If a few rotations per minute (RPM) of the rolling bearing) The impact of the failure, so in the analysis of bearing fault of low speed device is very accurate and effective. RockwelAutomation peak energy ( gSE) Refers to the impact roller micro cracks and defects produced by the vibration energy of the peak. The peak of vibration energy is produced by the repeated transient mechanical impact energy intensity measurement: the high frequency of using acceleration sensor in a certain range detection measure vibration energy. In the high frequency range, the mechanical impact energy will provoke the natural frequency of vibration of the machine structure response acceleration sensor as the carrier frequency and frequency of rolling bearing 暲 frequency modulation. The intensity of the impact energy is a function of pulse amplitude and repetition rate, the impact caused by acceleration sensor and handled by the unique filter and detection circuit, signal measuring large expressed as so when the rolling bearing failure, sparked by the pulse energy generated by the vibration energy will increase significantly. Therefore, the peak energy can effect in the rolling bearing status monitoring. Imbalance, misalignment and loose mechanical rotating machinery, such as common failure frequency signal is always reflected in the mechanical rotating speed frequency and the concentrated in low and medium frequency band ( 5 KHZ rolling bearing and gear in sha-lu spalling crack, rust, indentation, inside and outside, the cage failure, its operation process have very sharp pulse signal used gSE high-pass filter filter out some of the low frequency vibration signals, such as uneven Zhun namely fault frequency signal, and keep high frequency analysis of the rolling bearing fault signal. To filter the signal through a fengfeng value filter, the output signal is a sawtooth waveform. The sawtooth signal for further treatment, frequency amplitude (peak energy flux can be obtained GSE value) And peak energy spectrum ( GSE spectrum) By the gses spectrum can indeed to see rolling bearing defect frequency of barrier, gSE spectrum in the large amplitude spectrum line corresponding to the frequency f is bearing failure parts 暲 frequency, the fault characteristic frequency outside sha-lu BPFI in sha-lu BSF roller cage) , you can tell a part of the bearing failure. Envelope envelope analysis is one of the most effective method in fault diagnosis. It can be clearly indicates the location and severity of failure. Envelopment analysis mainly through selecting useful resonance frequency area, through filtering, translation, transformation, obtain inclusion failure frequency of low frequency envelope signal, the envelope spectrum analysis to diagnose the fault signal, which is also called envelope demodulation. Related to the fault signal envelope mediation mediation from the high frequency modulation signal, to avoid confusion with other low frequency interference, high reliability and sensitivity of diagnosis of envelopment analysis steps of analysis are: 1, comparison, normal and fault signal power spectrum, find business value maximum points, as the basis of interception frequency band. 2, draw the fault signal spectrum chart, based on power spectral clipping band shift of spectrum filter. 3, to intercept the signal amplitude on the double and zero padding, length of two times. 4, the complex frequency domain signal transform in time domain. 5, the time domain signal Fourier transform in frequency domain. 6, improve the frequency resolution and spectrum.