A gear grinding machine is a key piece of equipment used for precision finishing of the tooth surfaces of hardened cylindrical gears or specific gear cutters. Its main function is to eliminate thermal deformation caused by heat treatment and significantly improve the machining accuracy of gears, typically enabling gears to reach accuracy grades 6 to 3 or higher as specified in the GB/T 10095.1—2008 standard. When selecting a suitable gear grinding machine, multiple factors such as target accuracy, production batch size, number of teeth, and cost-effectiveness must be comprehensively considered.

Gear grinding machines are mainly classified into two categories based on their working principles: form grinding and generating grinding.

 

Form grinding utilizes a formed grinding wheel dressed by a dresser into a specific tooth profile for grinding. This method features a relatively simple machine structure and high processing efficiency, making it particularly suitable for mass production of gears with fewer teeth (e.g., less than 10 teeth). Its machining accuracy can typically reach grade 5, making it an ideal choice for pursuing high-efficiency production.

 

Generating grinding achieves precision machining by simulating the meshing process between a gear and a rack. Depending on the type of grinding wheel and the movement mode, it can be further subdivided into various methods.

 

Among them, the conical grinding wheel gear grinding machine uses the grinding wheel as a tooth of an imaginary rack, generating the involute tooth profile through pure rolling motion between the grinding wheel and the pitch circle of the workpiece. The machining accuracy of this method is usually between grades 7 and 5, and some high-end CNC models can even achieve stable grade 4 accuracy.

 

Another important generating grinding method (dish wheel gear grinding), which uses the edges of two dish-shaped grinding wheels as the two tooth surfaces of an imaginary rack, achieving machining through precise generating motion. This method has minimal thermal impact, allows for dry grinding, and is often equipped with automatic dressing and compensation devices, enabling stable and economical achievement of extremely high machining accuracy, typically reaching grade 4, and even grade 3 accuracy for ultra-precision gears under ideal conditions. However, its drawbacks include relatively weak rigidity of the grinding wheel headstock, low production efficiency due to single-tooth indexing, complex machine structure, and the need for dedicated accessories for different workpiece specifications, resulting in relatively high equipment and maintenance costs.

 

In summary, form grinding, with its advantages of high efficiency and relatively low cost, is more suitable for mass production scenarios; while generating grinding, especially dish wheel gear grinding, becomes the preferred choice when pursuing ultra-high precision and surface quality, despite its lower production efficiency and higher cost. In practical selection, a comprehensive judgment should be made based on specific production needs and technical requirements.