Based on the generation principle of spherical involute tooth surface, two new milling methods of spiral bevel gear, which break through the existing Gleason gear cutting system, motion control and simpler structure of gear cutting machine tool, are proposed. The specific research contents are as follows:
(1) Study on tooth surface generation and cutting principle of spherical involute spiral bevel gear
The generation principle of the tooth surface of spherical involute spiral bevel gear is analyzed by using the knowledge of three-dimensional analytical geometry and spatial kinematics, and the generation model of the tooth surface is established by using CATIA software. Finally, based on the generation principle of spherical involute tooth surface, the machining principle of generating spiral bevel gear tooth surface by taking the arc generating line as the cutting edge is analyzed.
(2) Motion analysis of three-axis linkage milling
Based on the generation motion analysis of spherical involute tooth surface, the cutting motion of spiral bevel gear is analyzed and transformed by using the knowledge of spatial geometry. The linkage cutting motion of three rotary motions is converted into two rotary motions and one linear motion. The cutting motion of concave and convex tooth surfaces of spiral bevel gears with different rotation directions is calculated and analyzed respectively, and the motion model generated by cutting is established.
(3) Structural design of milling cutter
The key geometric parameters of cutter teeth and the structure of cutter head are designed, and the three-dimensional solid model of cutter is established by CATIA software. Finally, the outer edge milling cutter for machining concave tooth surface and the inner edge milling cutter for machining convex tooth surface are designed respectively.
(4) Key mechanism design and computer simulation of three-axis linkage milling
Based on the analysis of gear cutting motion, the three-axis linkage gear cutting mechanism is analyzed and designed, and its three-dimensional solid model is established by CATIA software. In order to verify the feasibility of the new method of three-axis linkage milling of spiral bevel gear and the designed gear cutting linkage mechanism, the simplified model, tool model and gear blank model of gear cutting machine tool are established by using VERICUT software, and the NC program of gear cutting is compiled by using MATLAB and Excel software. Finally, the machining simulation of spiral bevel gear is carried out with the help of VERICUT software.
(5) Motion analysis of two axis linkage milling
Based on the research on the new method of three-axis linkage milling, a new method of two-axis linkage point milling with simpler cutting motion is proposed. Several discrete points are used to replace the arc generating line of the tooth surface, the three-axis linkage cutting motion is combined and transformed, the motion relations of the two-axis linkage cutting spiral bevel gear tooth surface are analyzed and studied, and the tooth surface generation motion model is established.
(6) Design of key structure of two axis linkage gear cutting machine tool
Based on the analysis of two axis linkage gear cutting motion, the two axis linkage mechanism of gear cutting machine tool is designed, and its three-dimensional model is established by CATIA software.
(7) Computer simulation of two axis linkage milling
Based on the two-axis linkage gear cutting motion analysis and the design of the key structure of the gear cutting machine tool, the simplified model, tool model and gear blank model of the gear cutting machine tool are established by using VERICUT software, and the NC program of gear cutting is compiled by using MATLAB and Excel software. Finally, the two-axis linkage machining simulation of spiral bevel gear is carried out under the machining simulation environment of VERICUT.
(8) Two axis linkage milling experiment and tooth surface deviation detection
Based on xk716 CNC milling machine, the prototype of two-axis linkage milling principle of spiral bevel gear is developed, and the design and processing of bevel gear blank and the purchase of cutting tools are carried out. Finally, the two-axis linkage milling experiment of spiral bevel gear is carried out. In this paper, 3906t gear measuring center is used to measure the tooth surface deviation of spiral bevel gear generated by cutting.