Experimental Study of Linear Profile Modification in Spur Gear Leg

Abstract

Gears with the involute profile are assumed to be rigid and good at producing mating gear. They are also deformable and deflectable, indicating additional space is required to avoid interference from the unpredictable shaft, misalignment, and dynamic factors. In addition, load and rotational speed cause frequent mild to severe interference leading to a significant reduction in its lifespan. This study conducted an experimental comparison between standard and modification involute gear profiles in a ratio of 1:2 to reduce interference. It was carried out using 18 pinion teeth with a 72 mm base diameter at three and four levels of torque load and speed. The load was also mounted a strain gauge on pinion gears to conduct strain measurement on the gear leg. Finally, it was applied using a mechanical brake measured by a dynamic torque meter. The experimental test obtained microstrain when the modified spur gear contacted for 3.04 – 6.67 milliseconds depending on the rotation speed and torque load. Modification of the linear involute profile significantly reduced the tooth leg strain at the rate of 5.6% to 13.99%. Meanwhile, the maximum microstrain reduction of 13.99% occurred at a speed of 1100 rpm and a torque load of 65%.

Keywords

• interference
• involute profile
• modification profile
• spur gear
• strain reduction