Gear processing process (7 steps make you feel simple)

Gear processing process (7 steps make you feel simple)

One method of gear machining is the forming method, that is, cutting the tooth shape with the form milling cutter which is completely consistent with the shape of the tooth groove to be cut, such as milling the teeth; The other is the generating method, which uses the meshing motion of the cutter and the passive gear to cut the tooth profile, such as gear hobbing and gear shaping. Let's have a detailed understanding of the gear processing process.

Gear processing process

1. Forging blank

Hot die forging is still a widely used blank forging process for automotive gear parts. In recent years, wedge cross rolling technology has been widely used in shaft processing. This technology is especially suitable for more complex stepped shaft blanks, which not only has high precision, small post-processing allowance, but also has high production efficiency.

2. Normalizing

The purpose of this process is to obtain the hardness suitable for the subsequent gear cutting, and prepare the structure for the final heat treatment, so as to effectively reduce the deformation of the heat treatment. The gear steel material is usually 20crmnti. Generally, the normalizing is greatly affected by personnel, equipment and environment. It is difficult to control the cooling speed and cooling uniformity of the workpiece, resulting in large hardness dispersion and uneven metallographic structure, which directly affects the metal cutting and final heat treatment, resulting in large and irregular thermal deformation and uncontrollable part quality. Therefore, isothermal normalizing process is adopted. Practice has proved that the use of isothermal normalizing has effectively changed the shortcomings of general normalizing, and the product quality is stable and reliable.

3. Turning

In order to meet the positioning requirements of high-precision gear processing, all gear blanks are processed with CNC lathes, mechanical clamping and non-regrinding turning tools are used, and the hole diameter, end face and outer diameter under one clamping are processed at the same time, which not only ensures the verticality requirements of the inner hole and end face, but also ensures the small size dispersion of large batch gear blanks. Thus, the precision of gear blank is improved and the machining quality of subsequent gears is guaranteed. In addition, the high efficiency of CNC lathe greatly reduces the number of equipment and has good economy.

4. Rolling and gear shaping

Common gear hobbing machines and gear shapers are still widely used in gear processing. Although the adjustment and maintenance are convenient, the production efficiency is low. If greater production capacity is achieved, multiple machines are required to produce at the same time. With the development of coating technology, it is very convenient to recoat the hob and cutter blade after grinding. The coated tool can significantly improve its service life, which can generally increase by more than 90%, effectively reducing the number of tool changes and grinding time, with significant benefits.

5. Shaving

Radial shaving technology is widely used in large-scale automobile gear production due to its advantages of high efficiency, tooth shape design and easy realization of tooth shape repair requirements. Since purchasing the Italian special radial shaving machine in 1995, the company has been mature and applied to this technology, and the processing quality is stable and reliable.

6. Heat treatment

Automobile gears need carburizing and quenching to ensure their good mechanical properties. For products that will not be processed after heating, stable and reliable heat treatment equipment is essential. The company has introduced the continuous carburizing and quenching production line of German Labor Company, and achieved satisfactory heat treatment results.

7. Grinding

It is mainly used for finishing the inner hole, end face, shaft diameter and other parts of the gear after heat treatment to improve the dimensional accuracy and reduce the geometric tolerance.