Effect of Shaft Misalignment on The Stresses Distribution of Spur Gears

Dr. Hani Aziz Ameen* Received on :17/8/2009 Accepted on:7/1/2010 Abstract Shaft misalignment is considered as one of the common repeated problems in most rotating machineries , which leads to generate vibrations and extra dynamic loads on transmitting gears teeth, also leads to nonuniformity in distribution of applied load along the meshing tooth face by being concentrated on one side of tooth face. The present work concentrated on the analysis of stresses generated on transmitting gear tooth, also studied the effect of misalignment angle on stress distribution and its concentration. This is important for the gear design and those who works in gear maintenance , because fracture is expected to initiate and propagate at locations of stress concentration . ANSYS program using finite element technique had been used, as this program is efficient and accurate tool in stress analysis, especially for complicated shapes. Gear tooth model had been analyzed using finite element method in three dimensions. After calculating transmitted 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 been calculated. The finite element program (ANSYS) had been executed for cases of misalignment angle (0°,0.2°,0.3°,0.4°,0.5°). The results showed clearly, that the stresses distribution and its concentration on tooth changed with misalignment angle and the equivalent stress is direct proportional with the misalignment angle. According to the values of generated stresses, the tooth fracture can be predicted.