1. Working principle of gear grinding machine

The essence of a gear grinding machine is to remove excess material from the tooth surface through the relative motion of the grinding wheel and the gear, using the high-speed rotation of the grinding wheel (cutting motion), ultimately achieving high-precision machining of parameters such as tooth profile and tooth guide. Its core motion includes:

（1）. Main movement

driving force for material removal.

（2）. Zhancheng Movement (Fancheng Movement)

Simulating the gear meshing process, the grinding wheel and the workpiece gear rotate at a fixed transmission ratio, ensuring that the grinding wheel edge trajectory forms an accurate involute tooth profile. For example, the grinding wheel can be considered the tooth surface of a "virtual gear," which, through meshing transmission with the workpiece gear, envelops the required tooth profile.

（3）. Feed motion

Radial feed: The grinding wheel moves along the radius of the gear to control the grinding depth and gradually reach the tooth thickness requirements

Axial feed: The grinding wheel or workpiece moves along the axis of the gear to achieve tooth direction (helix angle) processing, which is especially suitable for helical gears.

（4）. Indexing motion

After each tooth is ground, the gear is rotated precisely by a pitch angle to ensure the position accuracy of adjacent teeth, which is the key to ensuring the gear pitch error.

2. Principle differences of different types of gear grinding machines

（1）. Disc wheel gear grinding machine

Using two tilted disc grinding wheels, the end faces of the grinding wheels form the two tooth surfaces of the imaginary rack.

The grinding wheel is similar in shape to a worm (worm grinding wheel), and through meshing transmission (generating motion) with the workpiece, the full tooth width can be processed in one feed.

The grinding wheel shape is directly trimmed to a forming surface that matches the gear tooth groove without the need for generating motion. Each tooth groove is ground in turn through the indexing motion.

The tooth surface is ground using the side of a large-diameter flat grinding wheel, and generating motion is achieved through the tilting and rotation of the workpiece. It is suitable for the processing of large gears.