A Theoretical research into effects of tooth profile and assembly errors on the helical gear performance

ABSTRACT A THEORETICAL RESEARCH INTO EFFECTS OF TOOTH PROFILE AND ASSEMBLY ERRORS ON THE HELICAL GEAR PERFORMANCE KÜTÜK, M. Akif Ph.D. in Mechanical Eng. Supervisor: Assoc. Prof. Dr. Nihat YILDIRIM April 2003, 176 pages Effects of common gearing errors on helical gear performance are studied in this thesis. Pitch error, misalignment and pressure angle error are investigated errors. Thin slice theory is used for modelling the helical gear. Stiffness variation of the helical gear tooth pair, along contact length and along facewidth, is included in the model. Helical gear profiles are optimised for higher performance values for both existence of errors and error-free conditions. Transmission error is used as a performance indicator, as it causes kinematic inaccuracy and high dynamic loads, vibration and noise during operation. A computer program have been developed for design and analyses of spur and helical gear tooth profile for minimum transmission error. Outcomes of the study are compared with available literature and satisfactory agreement is observed. Analysing the variation of profile design parameters, amount of relief (or) and extent of relief (er), with geometric parameters; general helical gear profile design formulas for or and er are derived. Keywords: Helical Gear, Transmission Error, Profile Modification, Gear Noise Reduction iii