Design and Analysis of a Spur Gear: Contact Stress Variation with Eccentricity

Abstract

Contact stress analysis of gear drives is critical for predicting gear life and preventing surface failure. This paper investigates the variation of contact stresses in spur gear pairs due to eccentricity of the gear central hole, a manufacturing defect from poor workmanship. The analysis is conducted using ANSYS FEA software with eccentricity varied from 0.0 mm to 0.5 mm in 0.1 mm increments. Results show that von Mises stresses and von Mises strain increase with increasing eccentricity, while maximum deformation decreases. At 0.5 mm eccentricity, von Mises stress increases by 23.4% compared to the concentric case (0.0 mm). The FEM results at zero eccentricity are validated against Hertz analytical theory and AGMA standards, showing agreement within 4.2%, confirming the accuracy of the finite element model and demonstrating the significant impact of manufacturing eccentricity on gear contact stress distribution.