Efficient extraction method of friction fault characteristics in vibration signal of rotating shaft

A technology of fault characteristics and extraction methods, applied in measuring devices, instruments, measuring ultrasonic/sonic/infrasonic waves, etc., can solve problems that cannot be applied to engineering practice

Inactive Publication Date: 2014-04-16
SOUTHEAST UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

This method is mainly used in laboratories and cannot be applied to engineering practice
[0004] In the middle and late stages of friction faults, the friction characteristics are more obvious, and most of the above methods can judge the faults

Method used

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  • Efficient extraction method of friction fault characteristics in vibration signal of rotating shaft
  • Efficient extraction method of friction fault characteristics in vibration signal of rotating shaft
  • Efficient extraction method of friction fault characteristics in vibration signal of rotating shaft

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Embodiment Construction

[0046] This embodiment is based on figure 1 Taking the rotor test rig shown as an example, the analysis of the efficient extraction method for early friction faults is carried out.

[0047] The efficient extraction and analysis method for the friction fault of the rotating shaft involved in this embodiment is:

[0048] (1) Paste a reflective strip on the exposed shaft section, align the photoelectric sensor with the reflective strip, and measure the speed pulse signal, which is used as a benchmark for synchronous whole-period sampling and analysis of multiple measuring points.

[0049] (2) Arrange non-contact eddy current sensors with a sensitivity of 7.87mV / μm at different sections of the rotating shaft to monitor the vibration signal y(t) of the rotating shaft. (3) Set signal acquisition and analysis parameters:

[0050] Analysis frequency f a =20KHz

[0051] Acquisition frequency f s =5.12KHz

[0052] Sampling cycle number L=20

[0053] (4) Perform a differential ope...

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Abstract

The invention discloses an efficient extraction method of friction fault characteristics in a vibration signal of a rotating shaft, comprising the following steps of: selecting a plurality of monitoring sections along the direction of the rotating shaft; mounting an eddy-current transducer to monitor the vibration signal (t) of the rotating shaft; carrying out two times of differential continuously on time by virtue of the actually-monitored vibration signal and carrying out burr point enhancement operation on the signal processed by the two times of differential to obtain Z(t); calculating statistic characteristics of the Z(t) signal to obtain a sample average, a sample variance and a signal Z'(t) without an average value; calculating a signal distortion amplitude fault degree coefficient and a distortion frequency rate fault degree coefficient; calculating average values of the signal distortion amplitude fault degree coefficients and the distortion frequency rate fault degree coefficients in a plurality of periods, and taking the maximum value umax in the two average values as friction fault degree coefficients to judge the friction fault degree; and judging a friction position according to the friction fault degree coefficient of each measuring point of the rotating shaft. The method disclosed by the invention can effectively amplify the early-period friction fault characteristics and improve the diagnosis accuracy of early-period friction faults.

Description

technical field [0001] The invention relates to a method for extracting frictional fault features from vibration signals of a rotating shaft. Background technique [0002] In order to prevent the leakage of steam, compressed air, lubricating oil and other working media, steam turbines, generators, gas turbines, compressors, pumps, fans and other rotating machinery are equipped with various seals on both sides of the shaft, blade tips and bearings. The gap between parts is small, and friction between moving and static parts is easy to occur during operation. After the friction fault occurs, the vibration of the unit will increase, which will affect the safe and stable operation of the unit. In severe cases, it will lead to serious accidents such as large shaft bending and bearing bush fragmentation. According to incomplete statistics, more than 70% of the bent axis accidents of domestic power system turbogenerators are caused by friction faults. Efficient monitoring, analys...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01H17/00
Inventor 杨建刚李洁
Owner SOUTHEAST UNIV
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