A gear early fault detection method

Abstract

A vibration signal x(n) of a gear under each operation state is measured and obtained. A difference sequence delta x(n) of the vibration signal x(n) is obtained by performing a difference operation on the vibration signal. A fluctuation function F(s) of the difference sequence delta x(n) is calculated by using Detrended Fluctuation Analysis (DFA). The minimum value and the maximum value of a logarithmic fluctuation function ln[F(s)] at each operation state are extracted. A picture is drawn by respectively taking the extracted minimum value and maximum value as a horizontal coordinate and a vertical coordinate, and data points corresponding to the fault states are fitted into a ''fault state line'' by using a least square method. A confidence interval is estimated for the ''fault state line'' by using a certain confidence level (1-alpha). Along with the deterioration of gear operation states, the data points are gradually close to the established confidence interval. When the data points are in the confidence interval, it may be considered that a gear box has fault in a certain probability and the fault early warning is sent out, at this time the operation state of the gear box is analyzed detailedly, and if necessary, the shutdown maintenance is needed.

Description

technical field [0001] The invention relates to the field of state monitoring and fault diagnosis of rotating machinery, in particular to a gear early fault detection method. Background technique [0002] Gear is one of the key components of rotating machinery and has been widely used in industrial production. Its operating conditions not only affect its own operation, but also have a direct impact on related mechanical equipment. If the gear fails, it will affect the normal operation of mechanical equipment, and it will cause major economic losses, and even crash accidents and casualties. If during the operation of gears, people can use fault diagnosis technology to find potential hidden troubles in time and deal with them effectively, then not only can the safe operation of mechanical equipment be effectively guaranteed, but also major accidents can be avoided. Therefore, strengthening the research on gear early fault detection and diagnosis technology has important theor...

AI Technical Summary

Problems solved by technology

However, the above methods generally lack the analysis of the dynamic development process of rotating machinery faults, no corresponding evaluation criteria for the state of rotating machinery have been proposed, and no feasible state monitoring methods have been established.

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