Stress analysis on spur gears with stress relief hole

Gears are one of the most commonly used power transmission elements in machinery; It is one of the indispensable building blocks in many fields such as machinery, automotive, aviation, defense and medicine. During power transfer; quantities such as speed, torque, number of rotations and rotational speed; We can change attributes such as rotation direction and rotation axis with the help of gears. In order for the changes in these values to be appropriate, we change the following quantities in the gears; gear modulus, number of teeth, diameter of the turning circle, tooth thickness, root radius. This thesis discusses research on the possibility of reducing tooth root stresses by adding internal stress relief properties. Over the years, gear designs have evolved with the gradual addition of design features. Little has been done to change gear geometry to increase durability and power. Although the outside of the gear is governed by the required curved profile of the teeth, nothing prevents internal changes. In this study, holes were drilled along the axis of a test gear piece to provide stress relief in critical areas. A finite element model was constructed for use in a systematic test of the effect of hole size and hole placement on root stress. A constant force tangential to the section circle was applied. By using FEA software program, the maximum equivalent stress values were obtained for the gear wheels under load. After the analyses, all the results were compared. Accordingly, at the gear wheel dimensions preferred in this study, a maximum stress reduction of 9% was observed in gear wheels with holes compared to gear wheels without holes. Key words: Spur Gears, Stress Relief, Finite Element Method