The effect of working surface deviation on transmission error in helical gears

Transmission error (TE) of the gear system describes the difference between the perfect kinematic transmission of motion and the one actually achieved. It is proven that TE is the principal source of vibration through several previous studies. The elastic deformation of gear teeth and the geometrical deviation of teeth from the ideal involute curve are the two significant reasons for TE. Geometrical deviation produced by manufacturing error, especially, causes complicated phenomena including sideband and dominant high-order harmonics (2nd, 3rd) of gear meshing frequency in TE. For example, pitch and run-out errors have been demonstrated to cause the sideband, and tooth profile error on the working surface of the teeth can lead to dominant high-order harmonics of gear meshing frequency. In this study, the high-fidelity simulation model was developed considering working surface deviation of helical gears. To include such error in the simulation model, a computer numerically controlled (CNC) gear inspection machine was used. Multiple profile line-scanning measurement was conducted for all teeth along the radial direction, respectively, to represent the tooth working surface deviation with high resolution. Based on the measurement data, the analysis model was built using commercial software. The finite element method (FEM) was used for the housing and gear blank to reflect the elasticity of the components. For the calculation of gear mesh stiffness, the loaded tooth contact analysis (LTCA) considering the extended contact at the tips of the gear teeth was used. The non-linear bearing stiffness according to the amount of deflection was also considered in the simulation model. © 2023 The Authors.