The machining of automotive gears is a complex process that involves multiple steps and precise process control. The following are the main steps of automotive gear machining:

1. Design: Based on the functional requirements of automotive gears, design parameters such as gear profile, module, number of teeth, pressure angle, etc.

2. Material selection and preparation: Select suitable materials such as alloy steel, carbon steel, etc., and cut, forge or cast the materials to prepare the gear blank.

3. Forging billet: The billet is formed into the approximate shape of a gear through forging technology, which improves the density and mechanical properties of the material.

4. Rough machining: rough turning, rough milling and other processing are carried out on the gear blank to remove excess materials and preliminarily form the contour of the gear.

5. Heat treatment: Perform heat treatment processes such as normalizing, quenching, and tempering on gears to improve their mechanical properties, hardness, and wear resistance.

6. Semi precision machining: Semi precision machining is performed after heat treatment, such as semi precision turning, semi precision milling, etc., to further process the shape and size of the gear.

7. Gear profile machining: This is the core step of gear machining, including processes such as hobbing, gear hobbing, and gear shaving, to form the gear profile.

8. Precision machining: Precision machining such as turning, milling, and grinding of gears to achieve the final size and accuracy requirements of the gears.

9. Gear grinding: Grinding gears to improve their surface quality and accuracy, and reduce noise.

10. Heat treatment post-treatment: After the gear processing is completed, secondary heat treatment such as induction hardening, nitriding, etc. may be required to further improve the surface hardness and wear resistance of the gear.

11. Gear inspection: Through comprehensive inspection of gears, such as measurement of tooth flank clearance, gear hardness testing, gear accuracy testing, etc., ensure that the gears meet the design requirements.

12. Cleaning and Protection: Clean the gears to remove oil stains and iron filings generated during processing, and perform rust prevention treatment.

13. Assembly and Testing: Assemble the gears into the automotive transmission system and conduct tests to verify their performance and reliability.

Each step needs to be strictly executed according to the process standards to ensure the quality and performance of the gears. With the development of technology, gear processing technology is also constantly improving, such as using CNC machine tools, automated production lines, etc., to improve production efficiency and the quality of gears.