Effects of tip relief modification on static transmission error of spur gear

The most important factor for investigating noise between two gears is the transmission error. In this study, the static transmission error is calculated in a pair of mesh spur gear analytically. First, the compliance of a gear tooth is calculated considering three assumptions: cantilever beam deflection due to both bending and shear; rigid body tooth rotation at its base and Hertzian contact deflection. Through these assumptions and ignoring manufacturing, assembly and geometric errors, static transmission error is calculated for a pair of mesh spur gear. To reduce the noise, the tooth profile is modified by tip relief in this study. Then, the effect of this modification is investigated on the static transmission error via the contact ratio. Results show that tip relief modification of spur gear increases the contact ratio, therefore, the value of transmission error decrease. Consequently, the gear noise is decreased too.