The cutting technology of spiral bevel gear was first proposed by Ernst wildhaber and Meriwether L. Baxter of Gleason company in the United States. Later, Oerlikon company in Switzerland and Klingelnberg company in Germany also studied the cutting technology of spiral bevel gears and formulated their respective tooth systems. However, Oricon and Klingenberg proposed the bevel gear system with epicycloid tooth line, while Gleason proposed the bevel gear system with circular arc tooth line. At present, the spiral bevel gear made by Gleason is the most widely used bevel gear in spiral bevel gear.
The mechanical transmission spiral bevel gear cutting machine tools produced by Gleason company have a variety of styles. However, because the tooth surface of spiral bevel gear belongs to spatial surface and the tooth surface equation is extremely complex, the structure of gear cutting machine tool is particularly complex, and the control of gear cutting motion, machine tool adjustment and tooth shape correction are also very cumbersome and difficult. As early as 1954, Gleason took the lead in launching a spiral bevel gear cutting machine tool with model No.116, as shown in Figure 1. The machine tool is a pure mechanical transmission machine tool with a lengthy mechanical transmission chain. With the rapid development of computer technology, NC machining technology has been continuously improved and perfected, and the machining of spiral bevel gear is also developing rapidly in the direction of flexibility and intelligence.
In the mid-1980s, Gleason company launched Phoenix series spiral bevel gear CNC gear milling machine and gear grinding machine, of which the series 450hc gear milling machine is shown in Figure 2. This series of spiral bevel gear NC gear cutting machine tool cancels the tool inclination structure, shaking table mechanism, complex transmission link and adjustment link of mechanical transmission gear cutting machine tool in the earlier period. This fully CNC spiral bevel gear processing machine tool is a six axis five linkage universal CNC machine tool, which can process the tooth surfaces of spiral bevel gears with various tooth systems, and the processing accuracy can be improved by 1 ~ 2 grades compared with the mechanical transmission gear cutting machine tool. The Phoenix series gear cutting machines produced by Gleason company mainly include 250hc and 450hc gear milling machines and 200g, 450g and 800g gear grinding machines.
The wide application of Phoenix series spiral bevel gear CNC machine tools has brought great progress to the machining technology of spiral bevel gears. With the continuous improvement of the structure and cutting motion control of Phoenix series spiral bevel gear NC machining machine tools, Gleason company launched the most advanced Phoenix II series spiral bevel gear NC machining technology and its corresponding bevel gear machining machine tools at the beginning of the 21st century. As shown in Figure 3, the structural schematic model of Phoenix II Series CNC spiral bevel gear cutting machine tools is shown. This series of CNC spiral bevel gear processing machine tools redesigned and improved the bed structure. The workpiece box and tool spindle box are installed on the adjacent two sides of the bed column respectively, which makes the structure of the machine tool more compact, convenient workpiece disassembly, and improves the overall rigidity of the machine tool. Moreover, there is no machine tool element below the gear cutting processing area, which is very conducive to the flow of chips, so it provides more convenient chip removal conditions for dry milling and wet milling of spiral bevel gears. At the same time, all linear movement and rotary movement of this series of arc gear machines are directly driven by digital servo motor, which eliminates the middle gear driving link and greatly improves the machining quality of tooth surface. At present, Phoenix II series gear cutting machines produced by Gleason company mainly include 275hc and 600hc gear milling machines and 275g and 600g gear grinding machines.
With the continuous development and upgrading of computer technology, Gleason company has developed a set of advanced Gleason expert manufacturing system (GEMS) for Phoenix series gear cutting machine tools. The system integrates the object-oriented visual bevel gear software module and realizes seamless connection with Phoenix series spiral bevel gear cutting machine tools. It is an efficient bevel gear manufacturing system among computer optimization design, cutting motion control and machine tool adjustment. Gmes system mainly includes five modules: Computer Aided Gear Technology Engineering (cage 4win), Gleason gear automatic evaluation (g-agetm 4win), adjustment card management program (summary manager), finite element analysis (FEA) and universal motion design principle software (umctm).
Gems workflow: firstly, the data processing workstation is used to complete the design of spiral bevel gear by three modules: cage 4win, FEA and umctm, and determine the adjustment parameters and tooth surface measurement scheme of the machine tool, and then transmit the adjustment parameters and measurement scheme to Phoenix series bevel gear cutting machine tool through the summary manager machine tool adjustment card management module, Carry out cutting and machining of bevel gear tooth surface. The tooth surface data of spiral bevel gear generated by preliminary cutting is sampled and measured by Gleason Mar measurement system (GMX), and the tooth profile deviation is determined.
Then the measurement results and tooth profile deviation values are transmitted to the g-agetm 4win module, which automatically generates the machine tool adjustment parameters for tooth profile deviation correction and controls the gear cutting machine tool to complete the tooth profile correction. In general, in order to obtain higher precision bevel gear tooth profile, two cycle adjustments are needed to correct the tooth profile.
In the early 1990s, Oricon in Switzerland, Klingenberg in Germany and two other gear machine tool equipment manufacturing companies in Germany (Lorenz and Liebherr) formed a strategic partnership to form Sigma Σ pool group. The group has developed a series of spiral bevel gear cutting machines, bevel gear testing centers and cutting tools other than shaving machines, and independently developed a set of numerical control system and application software. Klingenberg company combines the spiral bevel gear processing machine tool with the measurement and correction of measurement parameters to launch KNC series spiral bevel gear CNC cutting machine tool. Oricon has improved the structure of the gear cutting machine tool, which is more conducive to the discharge of chips, and launched the c-series spiral bevel gear NC gear milling machine which can realize dry cutting. Many countries such as Japan and Italy have also conducted in-depth research and Discussion on spiral bevel gear processing technology, but its influence in the world is far less than that of Gleason, Oricon and Klingenberg, and the gear cutting principle and the structural form of machine tool are basically the same as Gleason’s.
Although with the continuous improvement of spiral bevel gear cutting technology, a series of high cutting-edge gear cutting machines have appeared in the world. However, these cutting machine tools and technologies have not changed the traditional machining principle and cutting technology of rocking bevel gear. Instead, the relationship between the adjustment parameters of the original gear cutting machine tool and the cutting motion is converted into digital instructions recognizable by the NC machine tool through a special translation program, and these instructions are used to control the multi axis linkage gear cutting motion, tooth profile correction and tooth surface regeneration of the NC gear cutting machine tool.