Machining technology of spiral bevel gear

With the continuous development of the world automobile industry, the machining technology of spiral bevel gear is also changing, and its machining method has always been a research hotspot. Spiral bevel gear processing technology can be roughly divided into two categories: one is machining technology, the other is precision forming technology.

The traditional processing technology of spiral bevel gear is generally formed by cutting the forged gear blank. NC gear milling machine is mostly used for tooth profile cutting. In order to ensure that the gear tooth surface is in local conjugate contact, it is necessary to calculate the complex nonlinear relationship among the machining parameters, tool parameters and contact area characteristic parameters of the gear milling equipment. The calculation of cutting adjustment parameters of spiral bevel gear and the error correction principle of tooth surface contact area are very complex, which requires the staff involved in machining and manufacturing to have good professional foundation and operation experience. After tooth milling, roll inspection shall be carried out on the rolling inspection machine, continue to process the tooth surface and adjust the contact area until the gear pair can mesh correctly. The finishing methods of spiral bevel gear mainly include gear grinding, gear grinding and hard tooth surface scraping. Among them, gear lapping method is widely used and has high production efficiency, but its correction ability is limited and can not eliminate the deformation error of heat treatment; Gear grinding has high machining accuracy, but the machining cost is high, the labor time is long, and the scraping of hard tooth surface is greatly limited by equipment, tools and other technologies. It is generally used to manufacture large gears. Generally speaking, the cutting process is still the main processing process for manufacturing spiral bevel gears, and the NC processing technology is also relatively mature, but this process still has some problems:

1) The forming mechanism of spiral bevel gear tooth surface is very complex, which will cause cumbersome cutting process, low efficiency and high technical requirements for operators.

2) Poor interchangeability. Gear pairs must be processed and used in pairs. When one of the gears has a problem, it must be replaced in pairs, resulting in a great waste of materials. For large-size gears, this waste is more serious.

3) In the process of tooth profile machining, the fiber tissue of the part is cut off, and its mechanical performance and fracture resistance are affected. Under the condition of overload, there is a hidden danger of tooth root fracture.