Fault Feature Analysis of Gear Tooth Spalling Based on Dynamic Simulation and Experiments

Area of Science:

• Mechanical Engineering
• Vibration Analysis
• Tribology

Background:

• Understanding gear fault mechanisms is crucial for predictive maintenance.
• Time-varying meshing stiffness (TMS) is a key parameter in gear dynamics.
• Tooth spalling significantly alters gear contact and stiffness.

Purpose of the Study:

• To develop a dynamic model of a gear system incorporating bearing and shaft dynamics.
• To analyze the effect of tooth spalling (rectangular and elliptical) on TMS.
• To investigate the fault features of gear tooth spalling through simulation and experimental validation.

Main Methods:

• Established a bearing statics model based on Jones bearing theory.
• Developed a lateral-torsion coupling vibration model using Timoshenko beam elements.
• Constructed a gear pair dynamic model using the lumped parameter method.
• Integrated component models to form a spur gear system dynamic model.
• Analyzed spalling influence on TMS using the potential energy method (PEM).

Main Results:

• Gear systems exhibit periodic shock responses due to meshing teeth variations.
• Tooth spalling, causing contact loss and reduced TMS, generates stronger shock responses.
• Spectral analysis reveals sidebands in the resonance region, indicating faults.
• Experimental validation confirmed simulation findings on spalling-induced vibrations.

Conclusions:

• The developed dynamic model accurately captures gear system behavior under fault conditions.
• Tooth spalling significantly impacts TMS and induces distinct vibration signatures.
• The study provides a theoretical foundation for gear health monitoring and fault diagnosis.