Large axial flow fan unbalance recognition method based on auto-correlation

Abstract

The invention discloses a large axial flow fan unbalance recognition method based on auto-correlation. The method includes that: 1) assuming that the vibration of an axial flow fan is caused by unbalance, the ratio of the amplitude of the power frequency signal of the axial fan vibration signal and the amplitude of other frequency signals is defined to be more than or equal to two, and the sampling length is more than the rotational speed signal cycle; 2) low-pass filtering is performed on the axial flow fan vibration signal; 3) dual auto-correlation is carried out to separate the power frequency component from multiple frequency components of the axial flow fan vibration signal; 4) effective value is computed to restore the amplitude of the power frequency component of the axial flow fan vibration signal; and 5) the amplitude measuring method is adopted for dynamic balancing to determine the size and position of the unbalance mass of the axial flow fan. The invention can effectively separate the unbalance vibration amplitude component from a complicated vibration signal on the premise that the key-phase signal is not extracted, finally locates the unbalance size and position of the axial flow fan through amplitude measuring balance method and has greater engineering application value.

Description

technical field [0001] The invention relates to the dynamic balancing technology of rotating parts, in particular to a method for identifying the unbalanced amount of a large axial flow fan based on autocorrelation. Background technique [0002] Large axial flow fans are easily disturbed by vibration caused by unbalance during use, which seriously affects the service life of the unit and the surrounding working environment. During the production process of large axial flow fans, although the impellers are dynamically balanced on the dynamic balancing machine, new unbalanced vibrations are often caused by assembly errors, collisions or deformation during blade installation and transportation. The motor of a large axial flow fan is enclosed in the casing, and the key phase signal required for balance can only be obtained by attaching a reflective sheet to the impeller and using a photoelectric head. It is difficult and dangerous to obtain the key phase signal correctly. As a...

AI Technical Summary

Problems solved by technology

[0002] Large axial flow fans are easily disturbed by vibration caused by unbalance during use, which seriously affects the service life of the unit and the surrounding working environment

During the production process of large axial flow fans, although the impellers are dynamically balanced on the dynamic balancing machine, new unbalanced vibrations are often caused by assembly errors, collisions or deformations during blade installation and transportation.

The motor of a large axial flow fan is enclosed in the casing, and the key phase signal required for balance can only be obtained by attaching a reflective sheet to the impeller and using a photoelectric head. Difficult to obtain the key phase signal correctly, and very dangerous

Therefore, it is difficult to use the conventional phase and amplitude measurement method for on-site dynamic balance testing. How to solve the unbalanced vibration problem of this type of rotating machinery has very important practical significance

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