Numerical investigation of the stress development in the involute spur gear under static load condition

Abstract

Among all the mechanical power transmitting elements, gear is one of the efficient ways to transmit power within a short distance. Generally, mechanically treated steels are used as conventional gear materials. But in recent years, researches have been conducted to use polymers and thermoplastics as gear materials. In this study, a numerical investigation has been done to compare 30% long glass fiber reinforced polyamide type-66 (PA66-GF30) with conventional steel gear and another polymer gear under same static loading condition. All three gears have same design parameters and were designed in Solidworks Premium 2016. The stresses were calculated using ANSYS 15 Static Structural analysis by Finite Element Analysis (FEA) technique. The loads were first calculated manually keeping the boundary condition for simulation as 132 HP at 500 to 6000 rpm (revolutions per minute). Three materials, namely Polyamide type-6(PA6), AISI1045 cold drawn steel and 30% long glass fiber reinforced Polyamide type-66 (PA66-GF30) taking under consideration among which the first two has been used frequently for various purposes. From the physical properties is was seen that the mass of polymer gears are remarkably less than that of steel gear. PA66-GF30 gear is about 5.5 times lighter and PA6 is about 7 times lighter than AISI 1045 cold drawn gear. But while considering stress analysis at the same loading, it was found that the induced stress in PA66-GF30 gear is about 4.9% less than that of AISI1045 cold drawn steel gear and about 2.67% higher than that of PA6 gear. The deformation rate for PA66-GF30gear was found to be satisfactory compared to the steel one. Thus PA66-GF30 gear can be a suitable replacement over steel gears for constructing light machinery without losing the strength.