Experiment on hobbing of spiral bevel gear end face

This paper studies the theory of tooth surface forming principle, geometric parameter design, cutting adjustment calculation, tooth contact characteristic control and optimization, full NC cutting, tooth profile measurement and deviation inverse adjustment of spiral bevel gear for end face hobbing, and uses relevant experiments to verify the above theoretical methods. A technical process of spiral bevel gear end face hobbing closed-loop manufacturing (design processing detection correction) has been preliminarily formed. The main work is as follows:

① This paper analyzes the relative motion relationship among cutter head, shaking table, workpiece and forming wheel in the basic machine tool model of end face hobbing, the continuous tooth division of end face hobbing and the formation principle of generating tooth shape. On this basis, the calculation method of pitch cone parameters and geometric parameters of gear blank of end face hobbing spiral bevel gear are studied, and the relevant calculation formulas are deduced.

② The basic theory of cutting adjustment calculation in face hobbing of spiral bevel gear is studied. A calculation method of cutting adjustment in face hobbing is proposed. This method can arbitrarily specify the position of contact reference point on the tooth surface according to the use needs, and can control the contact state of both sides of the tooth at the same time. In this method, the implementation formulas of key algorithms such as tooth cutting adjustment calculation of spiral bevel gear big wheel, position control of contact reference point, curvature parameter calculation of contact reference point of big gear surface, shape parameter control of contact area, curvature calculation of contact reference point of small gear surface, tooth cutting adjustment calculation of spiral bevel gear small wheel and curvature parameter guarantee are deduced in detail.

③ The contact analysis method of theoretical tooth surface of face hobbing spiral bevel gear is studied, and the influence law of contact characteristic control parameters on the shape parameters of contact area is analyzed. The results show that the tool inclination of large and small wheels mainly modifies the length of contact area and the amplitude of transmission error; The amplitude of the tool pair and the curvature of the tool face are corrected. The length of contact area, the diagonal direction of contact area and the amplitude of transmission error restrict each other. The length of the contact area of the concave and convex surface shall be basically the same value. When selecting the length of the smaller contact area and the diagonal direction of the larger contact area, the amplitude of the transmission error shall be a larger value.

④ The calculation method of internal excitation of spiral bevel gear meshing based on contact finite element method is studied. The influence of different contact zone shapes on the internal excitation of spiral bevel gear meshing is analyzed. On this basis, the tooth contact characteristics of face hobbing spiral bevel gear are optimized. After optimization, the internal excitation curve of spiral bevel gear pair is smooth, and its overall amplitude decreases by about 30%. The excitation amplitude under the first-order meshing frequency decreases by 9.6%, and the excitation amplitude decreases more obviously with the increase of meshing order.

⑤ The machining method of face hobbing of full NC spiral bevel gear is studied, and a direct solution method of tool position for face hobbing of full NC gear milling machine is proposed. The motion control method of machine tool for face hobbing on Siemens 840dsl CNC system is studied, and the control system of full CNC face hobbing machine tool is designed. The high-speed continuous tooth splitting motion and low-speed multi axis linkage tooth profile are developed into motion separation. The high-speed tooth splitting motion is controlled by the function of electronic gearbox, and the low-speed generation motion is controlled by spline interpolation. It is easy to realize the cutting of two processing methods of end face milling and end face hobbing on one machine tool. At the same time, in order to facilitate the operation of the machine tool, the NC machining software is developed based on 840dsl NC system according to the characteristics of end face hobbing.

⑥ The realization method of machining simulation of spiral bevel gear end face hobbing based on VERICUT software is studied. The tooth pitch and profile measurement method of end face hobbing spiral bevel gear based on domestic spiral bevel gear measurement center and the automatic correction method of tooth profile deviation with root deviation constraint based on optimization method are studied. Through the end face hobbing machining simulation, the full NC end face hobbing machining experiment of the real machine, and the coordinate measurement and rolling inspection experiment of spiral bevel gear, the correctness of the full NC end face hobbing machining method and NC machining software are verified; The correctness of the contact characteristic control method and the contact characteristic optimization method is verified.

Scroll to Top