A Contact Mechanics Model for Surface Wear Prediction of Parallel-Axis Polymer Gears

Area of Science:

• Tribology
• Materials Science
• Mechanical Engineering

Background:

• Surface wear is a primary failure mode for polymer gears, necessitating costly experimental testing for lifetime prediction.
• Existing methods for polymer gear wear analysis are often time-consuming and expensive.

Purpose of the Study:

• To develop and validate a contact mechanics model for predicting surface wear in polymer gears.
• To reduce the reliance on experimental testing for polymer gear lifetime assessment.

Main Methods:

• Utilized an iterative numerical procedure combining the boundary element method (BEM) with Archard's wear equation.
• Determined wear coefficients for Polyoxymethylene (POM) and Polyvinylidene fluoride (PVDF) using the VDI 2736 abrasive wear model.
• Incorporated Winkler's surface formulation for contact pressure and Weber's model for wear-induced stiffness and load-sharing changes.

Main Results:

• The developed model accurately predicts wear depth on contacting polymer gear tooth surfaces.
• Validated model predictions against experimental data for steel/polymer gear engagements.
• The model visualizes contact parameters influencing wear and predicts wear patterns at various lifetime stages.

Conclusions:

• The contact mechanics model effectively predicts polymer gear surface wear, significantly reducing experimental testing requirements.
• The model provides insights into wear mechanisms and patterns, aiding in the design and lifetime prediction of polymer gears.