Based on the generating principle of spherical involute tooth surface, a new method of cutting tooth surface of spherical involute spiral bevel gear is put forward, which takes the generating line of tooth surface as the cutting edge and the reverse movement of generating movement of tooth surface as the cutting movement. On the basis of the study of three-axis linkage cutting method, several discrete points are used to approximate the generation line of tooth surface, and based on the analysis of three-axis linkage cutting movement, the movement of point milling spiral bevel gear tooth surface is analyzed. A new method of two-axis linkage spiral bevel gear machining with simpler cutting movement is proposed. The main conclusions are as follows:
(1) The generating principle of the tooth surface of the spherical involute spiral bevel gear is analyzed. It is concluded that the concave tooth surface is formed by pure rolling on the base cone from the big end to the small end and from the base cone to the face cone, while the convex tooth surface is formed by pure rolling on the base cone from the small end to the big end and from the base cone to the face cone. In this paper, the motion relations of the generated tooth surface are calculated.
(2) Based on the generating principle of the tooth surface of the spherical involute spiral bevel gear, the cutting generating motion analysis of the tooth surface of the bevel gear is carried out. Taking the generating line of the tooth surface as the cutting edge and the reverse movement of the generating movement of the tooth surface as the cutting movement, the tooth surface of the spiral bevel gear can be cut only by three-axis linkage. Among them, the three linkage axes are the rotation of the gear blank ω 1, the rotation of the gear blank around the end point of the blade ω 2 and the rotation of the gear blank around the end point of the blade ω 2 and the movement of the gear blank along the cutting area and the adjustment area intersection line v. The relationship between the three speeds must satisfy the formula.
(3) The design of three-axis milling tool is carried out. The key geometric parameters and structure design of the milling cutter are carried out, and the milling cutter for machining the external edge of concave tooth surface and the internal edge of convex tooth surface are designed. Compared with the existing spiral bevel gear cutter, the structure of the cutter designed in this paper is greatly simplified, and the manufacturing and grinding are simple and convenient.
(4) The design of three-axis linkage gear cutting mechanism and the simulation of gear cutting are carried out. According to the analysis of the three-axis linkage gear cutting movement, a three-axis linkage gear cutting mechanism is designed. In Chapter 4, the basic cone angle adjusting mechanism, horizontal rotating mechanism and moving mechanism are used to realize the joint movement. Based on the analysis of gear cutting movement and the design of machine tool, the milling simulation of spiral bevel gear is carried out by using VERICUT simulation software, which verifies the feasibility of the designed gear cutting machine tool and the new method of three-axis linkage gear milling.
(5) On the basis of the study of three-axis linkage gear cutting method, a new method of two-axis linkage point milling with simpler gear cutting movement is proposed, and the movement of two-axis linkage gear cutting is analyzed, and a two-axis linkage gear cutting scheme is developed. Using CATIA software, a simplified three-dimensional model of the key mechanism of the spiral bevel gear two-axis linkage gear cutting machine is established, and how to realize the various movements required by the mechanism for the processing of the spiral bevel gear tooth surface is analyzed.
(6) The machining simulation of spiral bevel gear with two axes linkage is carried out. Using VERICUT software, the models of gear cutting machine, cutter and blank are established respectively. Then, using MATLAB and Excel software, the CNC program of spiral bevel gear machining is compiled. Finally, the simulation of gear cutting is carried out in VERICUT environment. The feasibility of the new method and the designed cutting machine is verified.
(7) The principle prototype of the two axis gear cutting machine is developed, and the experiment of gear cutting is carried out. On the basis of xk716 CNC milling machine, the key functional parts are added, the principle prototype of two-axis CNC milling machine is developed, and the design and processing of bevel gear blank are carried out. Finally, the cutting experiment is carried out, and the sample of spiral bevel gear is cut. Using 3906t type gear measuring center to measure the tooth surface deviation of the processed bevel gear, the measurement results show that the normal deviation of the tooth surface is between -0.0227mm and 0.0097mm, which further verifies the new method of two axis linkage gear cutting proposed in this paper.