Design analysis and fabrication of a 24 -teeth spur gear from HT250 gray cast iron

Abstract

Spur gears are types of gears used for transmitting motion between two parallel shafts. This machine often encounters failure and downtime as a result of failure of the gear component. These failures include; pitting, scoring, fracture, wear, and so on. This study focused on the use of Gray Cast Iron (HT250) to develop a spur gear having 24 teeth and a protruding connecting shaft to link it to a machine using keys or other means. The fabrication process that was used to obtain gear was Casting which was done in the Foundry Workshop of the Mechanical Engineering Department in Covenant University. The failure indicated on the gear was a cyclic failure due to fracture. The stress analysis was carried out on this element using this software. A cyclic force of 10 N was subjected to the gear and the following values were obtained: the maximum Von-mises stress was 3.548 x 105N/m^2 and the minimum was 5.629 x 10-1N/m^2, The maximum displacement or deflection gotten was 6.306 x 10-5 mm and minimum is 1 X 10-30 mm, The maximum strain gotten was 2.599 x 10^-6 and the minimum was 9.825 x 10^-12. Various parameters were used to obtain the nature of failure on the material such as the force on 10 N on a single tooth and on all 24 teeth, a torque of 10 N/m, temperature of 50-degree, pressure of 20 Pa and centrifugal force of 5 rad/s. These results to variation in the von mises stress.