Precision gear refers to a mechanical element that has a gear on the rim for continuous meshing to transmit motion and power. The application of gears in transmission has appeared very early. With the development of enterprise production, the stability of precision gear operation has been paid attention to.
The micro-deformation control and process stability control in the gear machining process are more complicated. In order to obtain good machinability and a uniform metallographic structure that tends to deform, isothermal normalizing should be used after forging. For low-speed spur gears with lower precision, the teeth can be shaving before heating, but not processed after heating. The application of radial shaving method expands the application range of shaving teeth. There are two methods for hot finishing of cylindrical gears: honing and grinding. The honing cost is low, but the tooth profile correction ability is weak, the tooth grinding precision is high, and the cost is high.
Spur bevel gears are mainly used for differential gears. Because of its slow speed and low precision, precision forging has become an important research direction for economic development. In the process of calculating the machining method and adjusting the structure of the spiral bevel gear machine tool, modern special software and computer applications have replaced the complicated and time-consuming manual operations that were necessary in the past. The introduction of finite element model analysis makes the optimization of process parameters safer and more reliable. and convenient. There are two methods for hot finishing of spiral bevel gears: grinding and grinding. Due to the high cost, low efficiency and limitations of the spiral bevel gear grinding, the grinding method is mainly used at present, and the driven gear mainly adopts the carburizing pressure quenching process. The development of gear material engineering and its heat treatment technology is a challenging subject for gear deformation control.
Precision gear machining can use a variety of machining techniques from grinding to hobbing. Because hobbing is generally more efficient, hobbing is used more widely in production than any other method of machining large gears.
Current trends in technology to improve the efficiency and accuracy of large gear cutting include:
1. Advances in tool technology (especially coating and base material technology) for gear processing.
2. Exploration of the optimal design of large gear cutting tools.
3. The gear machining cutting machine is more flexible, or more machining operations can be completed in one clamping.
With advances in tool coatings and substrates, dry cutting continues as a trend in the gear machining industry, increasing cutting speeds and extending tool life without the use of cooling lubricants. At present, dry cutting has become the standard process of bevel gear machining. At the same time, the machining of parallel axis cylindrical gears is gradually shifting to dry cutting.