Meshing Characteristics And Load Capacity Analysis Of Orthogonal Curve-face Gear

Orthogonal curve-face gear(or ORC gear, for short) pair is a new gear pair which is established on the foundation of face gear pair and bevel gear pair and can transmit motion and power between concurrent axes. The ORC gear pair combined the characteristics of face gear pair, bevel gear pair,non-circular bevel gear pair and non-circular gear pair which has the advantages of low mass, light weight,easy to machine and so on. This new gear pair has the potential prospect in engineering machinery, automobile and so on.This issue comes from the Natural Science Foundation of China “Design theory and manufacturing technology of fluctuating gear ratio face gear”(NO.5125537), to explore a universal method of design for the meshing characteristics and tooth load capacity of the ORC gear pair. In order to solve the intensity problem of the ORC gear pair, the main works in this thesis is as following:Based on the spatial gear meshing theory, the basic transmission theory and the spatial meshing coordinate system were analyzed and established. The parameter equations of pitch curve, addendum curve, and dedendum curve of ORC gear were deduced. Meanwhile, the parametric equations of ORC gear profile were derived.Based on the deferential geometry, the method for calculating the principle curvatures of ORC gear pair was obtained. Meanwhile, the changing rule of the principle curvature of ORC gear in half period was obtained. The formula for calculating the pressure angle of ORC gear pair was deduced, and the influence of basic parameters of ORC gear pair on the pressure angle was analyzed. The formula for calculating the contact ratio of ORC gear pair was deduced. Thus, the influence of basic parameters of ORC gear pair on the contact ratio was analyzed.The force situation of ORC gear pair is analyzed, and the influence of basic parameter on the tangential force and axial force was obtained. On the basis of Herze contact theory, the formula of contact stress of ORC gear pair was obtained. Regard the ORC gear transmission as a non-circular rack transmission using the thought of equivalence. According to the handbook of gear design, the formulas of equivalent tooth form factor and equivalent stress correction factor were derived. Therefore, the formula of bending stress of ORC gear was obtained, and the impact of basic parameters on contact stress and bending stress were analyzed. A universal strength design software of ORC gear pair was developed with VB.Bending stresses during meshing process were measured under the static load using the strain gauge method which verified the correction of the calculating method. Establishing the experiment platform and obtaining the loading moment to verify the correction of calculation method of contact stress indirectly. Using the method of the finite element method, the locations and values of biggest stresses in meshing procedure were derived. Comparing with the results of theory and test, the calculation methods of bending stresses and contact stresses were verified.