Computer aided design of helical gear teeth profile for optimum motion transfer

ABSTRACT COMPUTER AIDED DESIGN OF HELICAL GEAR TEETH PROFILE FOR OPTIMUM MOTION TRANSFER KÜTÜK, M. Akif M.S. in Mechanical Eng. Supervisor: Asst. Prof. Dr. Nihat YILDIRIM June 1997, 80 pages In this thesis, a study on the design and optimisation of helical gear teeth using the thin slice theory is presented. Helical gears are optimised for lower values of transmission error, because transmission error causes both kinematic inaccuracy and high dynamic loads, vibration and noise during operation. Helical gears are represented by thin spur gears packed together with an off-set between each one in accordance with the helix angle. Thus, well established transmission error theory of spur gears is used in analysis and design of helical gears. A simple iteration technique is used in optimisation of the teeth profile modification based on the objective function of minimum transmission error and gradual tooth load diagram at design load. A computer program is written to accomplish the iteration based on the thin slice theory and on the assumption made. Comparison of the optimisation results produced by the computer program with the theoretical and experimental results in literature has shown that the technique is satisfactory in optimising the helical gear modifications. Keywords: Transmission Error, Profile Modification, Gear Noise Reduction m