Analysis On Transmission And Tooth Contact Characteristics Of Curve-face Gear

Curve-face gear pair is a new type of face gear pair which is established on the foundation of traditional face gear pair and bevel gear pair. It combines transmission characteristics of bevel gears, face gears, non-bevel gears and non-cylindrical gears and can transmit variable transmission ratio motion and power between concurrent axes. It has the characteristics of small size, light weight etc., so it has broad application prospects in some special fields such as textile machinery, agricultural machinery, engineering machinery, automobiles 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 analysis on characteristics of tooth load contact of curve-face gear. In order to solve the tooth load contact problem of curve-face gear pair, the main works in this thesis is as following:Based on the gear spatial meshing theory, the basic transmission theory of gear pair was analyzed and the spatial meshing coordinate system was established. The parameter equations of pitch curve, dedendum curve, addendum curve and instantaneous axis face of gear pair were deduced. The equations of contact ratio of curve-face gear pair were proposed by transforming curve-face gear pair to gear rack and pinion, and the influences of basic parameters of cutter gear and gear pair on contact ratio is analyzed.Based on the gear spatial meshing theory, a calculation method of tooth contact analysis of point contact curve-face gear was proposed, the point contact meshing equation of the gear pair was derived, and the tooth contact characteristic analysis of the gear pair was completed. Based on the point contact Hertz theory, the load tooth contact characteristic analysis of gear pair was conducted. The calculation equations of semi-major and semi-minor axis of contact ellipse were obtained and the visual simulation of contact ellipse was realized, the maximum contact stresses of contact ellipse center of curve-face gear was analyzed. Based on the gear spatial meshing theory, the transmission error of point contact curve-face gear pair is analyzed.Based on the gear spatial meshing theory, a calculation method of tooth contact analysis of line contact curve-face gear was proposed, the line contact meshing equation of the gear pair was derived, and the tooth contact characteristic analysis of the gear pair was completed. Based on the line contact Hertz theory, the load tooth contact characteristic analysis of gear pair was conducted. The calculation equations of the width of contact area were obtained and the visual simulation of contact area was realized, the maximum contact stresses of the contact line of curve-face gear were analyzed. Based on the gear spatial meshing theory, the transmission error of line contact curve-face gear pair is analyzed.Based on the modern manufacturing technology and methods, the point contact and line contact curve-face gear pairs were processed by five-axis CNC machining center. The contact prints of gear pairs were obtained by the gear rolling experiments and finite element analysis method. Comparing with the results of theory and test, the analysis on characteristics of tooth load contact of curve-face gear was verified.