Master of Science, The Ohio State University, 2020, Mechanical Engineering

In this study, an asymmetric tapered plate model is used to study the deflections of an asymmetric involute gear tooth. The bending and shear compliance of the plate was solved using the semi-analytical Rayleigh-Ritz energy method. The transverse deflection from the shear plate model were shown to be in excellent agreement with Finite Element Method (FEM) results, with acceptable normalized errors for different load cases. Computational efficiency of this semi-analytical model over FEM allows it to be used in Load Distribution Program (LDP), an existing gear analysis program, for predicting the load distribution, loaded transmission error, root stress, contact stress, mesh stiffness, tooth forces and other design evaluation parameters. A profile generation method for asymmetric gears from arbitrary rack profiles is used to predict root stresses using Boundary Element Method (BEM) in LDP. Root stress predictions are made for pressure angles. Two cases of pressure angle variation for asymmetric gears with drive pressure angle greater than coast pressure angle are explored, (i) Increasing drive pressure angle while keeping coast pressure angle constant, (ii) Decreasing coast pressure angle while increasing drive pressure angle. Results indicate that bending stress reduces considerably in case (i) as the drive pressure angle is increased. In case (ii), root stresses remain unaffected on increasing asymmetry.

Committee: David Talbot (Advisor); Ahmet Kahraman (Committee Member) Subjects: Design; Mechanical Engineering; Mechanics

Master of Science, The Ohio State University, 2011, Mechanical Engineering

Wind energy has received a great deal of attention in recent years in part due to its minimal environmental impact and improving efficiency. Increasingly complex wind turbine gear train designs, well-known rolling element bearing failures, and the constant push to manufacture more reliable, longer lasting gear trains generate the need for more advanced analysis techniques. The objectives of this thesis are to examine the mechanical design of Orbital2 flexible pin, multi-stage planetary wind turbine gear trains using three dimensional finite element/contact mechanics models. These models are constructed and analyzed using software that specializes in elastic gear tooth contact. Computational results, such as gear tooth root strain, are compared to full system experiments. Root strain is calculated at multiple locations across the facewidth of ring gears from the computational models and compared to experimental data. Computational results for tooth load distribution and planet load sharing factor are compared to experiments. The computational models consider gear misalignment and carrier eccentricity and permit design recommendations for improving tooth load distribution and planet load sharing.

Committee: Robert Parker PhD (Advisor); Sandeep Vijayakar PhD (Committee Member) Subjects: Design; Energy; Engineering; Mechanical Engineering; Mechanics