Virtual Machining Of Spiral Bevel Gears

Spiral bevel gears are used for transmitting the rotational motion of the crossing axes with the constant transmission ratio. Because of spiral bevel gears' feature, such as the high carrying capacity, the big overlap coefficient, the high stability, the low noise and vibration, spiral bevel gear is widely used on the high-power machine,such as the automobile, the airplane and the mining machine. The geometry characteristic and the engagement process of spiral bevel gears are very sophisticated. The structure of the machine , the cutting process and the parameters' adjusting are also complicated. In addition the modification of many parameterers, the machining tools, machine adjusting, loading deformation, assembly error can cause the changes of its engagement, loading and vibration characteristic. Thus the control of the quality and the performance is very difficult in the process of designing and manufacture. The traditional cutting method is to realize the preferable contact area through many test-cutting and machine adjusting, which need the skill worker, the long process period which cause the high cost. There are three companies, GLEASON in America, OERLIKON in Switzerland and KLINGEIBERG in Germany. They keep their technique secret and others hardly acquire the machining technology about spiral bevel gears.In this paper, the manufacturing process of spiral bevel gears is simulated and the mathematics model of the cutting machine for arc bevel gears is established. The detail course is to set up the coordinate of the machine and the workpiece, use the intersection of the tool tracing line caused by the adjacent edge in the cutting process as the point on the flank, deduce the function of the flank and program the cutting process of spiral bevel gears using VISUAL BASIC language. The most important feature of this program is that it resemble the practical machining process.Both the forming process of gears and the adjusting process of cutting parameters for the machining tools are similar to the factal process.Thus users can directly adjust the cutting parameters in computer and simulate the cutting process according to the detail requirement to get the satisfied cutting parameter and the satisfied product. In 3D software, the 3D model of the spiral bevel gear can be obtained through the flank points from the cutting tooth program. Then the detection for interference and intension of gear pair can be carried out. If the abovemethods were adopted, the adjusting time, test-cutting time and the raw material would be saved much and the labor intension would be reduced.In this paper, an example to get the 3D model from point clouds which come from the cutting tooth program and carry out the interference test was given. According to the result of interference test, the cutting tooth parameter is adjusted till the satisfied spiral bevel gear pair was acquired.