Effects of modification on the strength–weight ratio of standard bevel gears

Because of the current rapid technological progress, in addition to achieving increased speed and momentum in machine, transmitting more power in a low-noise, lightweight, safe, and economical manner and saving material in gears is crucial. For this purpose, modified bevel gears are common. Therefore, this study investigates bevel gear profile modifications focusing on strength and raw material saving. Herein, three modification designs (Modifications I–III) were modeled using CATIA software. Finite element analysis (FEA) and experimental tests were performed to investigate the effect of the proposed modifications on the gear's strength. Design and analysis procedures of the modifications were presented. Prototypes of the modified gear pairs were fabricated and subjected to strength and wear tests using a dynamic test device. The fatigue life of each gear pair was determined using nCode software. Modification II reduced the gear root stress by 3.98% relative to the original gear pair. Modification III resulted in 37.30% material saving, accompanied by 6.74% increase in contact stress. No fatigue damage was detected in either modification gear pair. The FEA results were compatible with the analytical, i.e., KISSsoft simulation, and experimental results; furthermore, FEA was found to be advantageous in terms of time and test costs in gear modification. Based on the obtained results for the three modifications, the Modification II gear pair is recommended for mass production.