RESEARCH ON THE IMPACT OF CORNER CONTACT OF SPUR TRANSMISSION

摘要

Corner contact widely occurs in spur gearing when considering the machining accuracy and loading. It brings meshing impact when beginning or ending contact and causes the variation of mesh stiffness, which leading to vibration, impulsion and noises, and intensifying the teeth loading. The studies show that the contact impact before or after the normal path is one of the main factors. Considering the effect of different impacts to gear transmission, the contact impact before the normal path to spur gear engagement will be investigated in this paper. Based on the impact mechanism of corner contact and the effects on spur gearing, the equivalent error and distortion of gear teeth are considered. The equivalent error is composed by the law of statistical distribution of base pitch error and profile error, and the integrated distortion includes the deflection due to bending compression, shear, localized Hertz contact and foundation distortion. Based on the numerical solution of teeth compliance by load-history analysis from the exact finite element method model of gear, and due to the kinetic model of impulse contact before the normal path, and considering the error and distortion of gear teeth, the original locality of the point situated at corner contact is probed , and the impact velocity and forces as well. The results are compared with relative references and standards, which proved reasonable. Then the location, impact velocity and forces, from the point situated at corner contact to theoretical line of action, are calculated accurately.