Effect of Shaft Misalignment on The Stresses Distribution of Spur Gears

Abstract

Shaft misalignment is considered as one of the common repeatedproblems in most rotating machineries , which leads to generate vibrations andextra dynamic loads on transmitting gears teeth, also leads to non- uniformity indistribution of applied load along the meshing tooth face by being concentrated onone side of tooth face. The present work concentrated on the analysis of stressesgenerated on transmitting gear tooth, also studied the effect of misalignment angleon stress distribution and its concentration. This is important for the gear designand those who works in gear maintenance , because fracture is expected to initiateand propagate at locations of stress concentration . ANSYS program using finiteelement technique had been used, as this program is efficient and accurate tool instress analysis, especially for complicated shapes. Gear tooth model had beenanalyzed using finite element method in three dimensions. After calculatingtransmitted load and dynamic load, misalignment angle had been changed from(0°,0.2°,0.3°,0.4°,0.5°) then its effect on distribution of applied load had beencalculated. The finite element program (ANSYS) had been executed for cases ofmisalignment angle (0°,0.2°,0.3°,0.4°,0.5°). The results showed clearly, that thestresses distribution and its concentration on tooth changed with misalignmentangle and the equivalent stress is direct proportional with the misalignment angle.According to the values of generated stresses, the tooth fracture can be predicted