Effect of strain rate on bending and transmission characteristics of injection molded polyamide 66 spur gears

Abstract

Polymer material exhibits time-dependent mechanical behavior due to its viscoelastic characteristics. Thus, unlike steel gears, polymer gears exhibit complex behavior when transmitting loads at various rotational speeds. In general, gear tooth surfaces exhibit complex stress due to their nonconformal geometry. Hence, the nonlinear material and nonlinear geometric aspects of polymer gear mesh prompted an investigation of the bending and transmission characteristics of injection molded polyamide 66 gears at various strain rate conditions. The injection molded tensile specimens made from the gear material were subjected to various rates of loading. The stress–strain performance at various rates of loading was evaluated and used to model linear and nonlinear gear materials for the numerical analysis. The numerical investigation was carried out on the steel–polyamide gear pair with the commercial finite element analysis tool ABAQUS® to predict the bending stress and static transmission error. The predicted static transmission error of the gear pair was compared with the experimental results obtained using an in-house developed gear test rig. The bending stress with the linear material models was higher than that of the nonlinear material models. An increase in bending stress with the strain rate was observed in the case of the nonlinear material models. The static transmission error predicted with the nonlinear material model at a higher strain rate was lower for both the single tooth contact and the double teeth contacts.

Dynamic response analysis of functionally graded gears

“…The design and performance of lightweight polymer and polymer composite gears have also been studied extensively in the literature, but their application is limited to low power transmission applications only. [16][17][18][19][20][21][22][23] Bi-metal and hybrid gears provide an appreciable weight reduction and performance comparable to steel gears. But the drawback of these gears is the problem of delamination and the presence of high-stress concentration on the joining interface due to abrupt changes in the material properties.…”

“…The design and performance of lightweight polymer and polymer composite gears have also been studied extensively in the literature, but their application is limited to low power transmission applications only. 16–23…”

Influence of tooth asymmetry and mating gear material on the tooth deflection characteristics of polymer gears

“…The deflections predicted using Marlow’s hyper-elastic model were greater than that of the linear elastic model. Kodeeswaran et al 15 predicted the static transmission error of Nylon 66 gears using a non-linear, elasto-plastic model to investigate the loading rate effect. As the loading rate increased, the difference between the numerically predicted and experimentally measured values of STE at pitch point decreased.…”

“…A comprehensive review of the existing literature reveals that mesh and tooth stiffness characteristics of asymmetric polymer gears have not been investigated so far. Detailed studies have been conducted to evaluate the tooth deflection and the consequent variations in transmission behavior of symmetric polymer gears using analytical, 2,8,10 numerical 2,9–11,14–16 as well experimental methods. 2,9,12,13,15 As stated earlier, for the case of asymmetric gears, the research related to the stiffness behavior has been relatively limited and focused solely on metal gear pairs.…”

Transmission Efficiency and Surface Damage of Polymer–Polymer Gear Pair Under Wet Lubrication

“…Polymer material exhibits inferior wear and poor heat resistance, which affects the transmission performance of gears. Usage of reinforcement would reduce the amount of frictional and hysteresis heating [1,8,14]. Multiple works have been carried out to understand the behavior of polymer-polymer and metal-polymer gear pair under unlubricated condition.…”