Gear transmission system nonlinear stability-based fault diagnosis method

Abstract

The invention relates to the technical field of mechanical fault diagnosis, and in particular to a gear transmission system nonlinear stability-based fault diagnosis method. The method specifically comprises the following steps of: S1, establishing a multistage gear transmission system torsional dynamic equation which comprises a system motion differential equation and time-varying meshing stiffness (total stiffness, a crack model and a gear break model); S2, testing nonlinear features of a response signal; S3, carrying out sub-harmonic resonance and stability analysis; and S4, analyzing influences, on system stability, of faults, wherein the influences comprise but are not limited to influences, on sub-harmonic resonance, of planet gear break faults, influences, on sub-harmonic resonance,of fixed shaft crack faults, influences, on sub-harmonic resonance, of gear missing faults, influences, on sub-harmonic resonance, of wear faults and influences, on system stability, of coupling faults. According to the method, a multistage gear transmission system dimensionless dynamic equation with a two-stage fixed shaft gear and a one-stage planet gear is established from the angle of nonlinear dynamics, so that nonlinear characteristics such as bifurcation diagrams and the like of systems can be obtained.

Description

technical field [0001] The invention relates to the technical field of mechanical fault diagnosis, in particular to a fault diagnosis method based on the nonlinear stability of a gear transmission system. Background technique [0002] In the design of gears, reasonable gaps are allowed to exist, but with the increase of running time, the gears have wear, deformation, cracks, fractures and other faults, which make the original design parameters of the gear system change, resulting in the original stable reciprocating collision periodic motion It evolves into abnormal system vibration, which affects the stability, safety and life of the system. [0003] For a multi-stage gear transmission system, the nonlinear vibration between the gears of each stage will be coupled to each other, making the vibration of the multi-stage system more complicated, and the stability after coupling becomes unknown, so it is necessary to conduct in-depth research on its stability . [0004] The c...

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Problems solved by technology

[0002] In the design of gears, reasonable gaps are allowed to exist, but with the increase of running time, the gears have wear, deformation, cracks, fractures and other faults, which make the original design parameters of the gear system change, resulting in the original stable reciprocating collision periodic motion Evolves into abnormal system vibration, which affects the stability, safety and life of the system

[0003] For a multi-stage gear transmission system, the nonlinear vibration between the gears of each stage will be coupled to each other, making the vibration of the multi-stage system more complicated, and the stability after coupling becomes unknown, so it is necessary to conduct in-depth research on its stability

[0004] The coupling characteristics make the multi-stage gear transmission system unstable, and the subharmonic resonance phenomenon in the system is changed by the influence of design parameters and coupling characteristics, which is easy to cause system instability

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