Bilateral wear analysis of crowned spline coupling subject to angular misalignment

In order to enhance the wear resistance of spline couplings, it is necessary to study the impact of crowning modification on wear behavior. The present work conducts ball-on-disc wear experiments to determine the wear coefficient of the spline material. A method is developed to calculate the wear volume of the ball by reconstructing its 3D profile from the 2D boundary of the wear scar. Subsequently, a bilateral wear method based on the Archard wear model is proposed and validated by comparing the ball-on-disc experimental measurements with the simulated results. The method is then applied to a simplified model for splines under various misalignment angles. The results show that the slip path of the nodes on spline forms non-closed loop, and the sliding mode closely resembles a unidirectional sliding. The initial wear rate of the crowned spline is lower than that of the uncrowned spline at a certain misalignment angle, but both regions can reach a similar level of wear rate during the steady stage. The maximum wear depth linearly increases along with the loading cycles during the steady stage, and the wear life is thus predictable based on a fitting equation. Although crowning elongates the wear life of the spline, it is still inadequate to meet the expected service life. Therefore, critical wear coefficients are identified to satisfy the design life requirements and guide material strengthening.