There are four commonly used repair methods when the tooth surface of a gear is worn during the adjustment and displacement method, the displacement cutting method, the tooth insert repair method, and the surfacing repair method.

1. Adjustment and transposition method: Change the orientation of the worn gear and continue to work using the parts of the gear that are not worn or slightly worn. Applicable to the repair of gear transmission mechanisms with unilateral wear of gear teeth caused by one-way operation stress. For single sided wear gears with symmetrical structure, they can be directly inverted by 180 ° for reinstallation and use; For gears with asymmetric structure, the asymmetric structure (non gear teeth) that affects installation can be removed, and the corresponding structure can be added at the other end by welding, riveting, and other methods. After that, the gear can be installed and used by turning over 180 °. It is also possible to add an adjusting washer on the shaft where the gear is installed without adding a structure to adjust the gear to the correct position for use, but it is better to turn it over in pairs or replace the matching gear with a new one to ensure normal gear engagement. Bevel gears or gears with forward and reverse rotation cannot be repaired by adjusting and transposing.

2. Displacement cutting method: We use the method of high displacement to turn off the outer diameter of the scrapped large gear to a certain value, and then re hobbing the gear to remove the pitting on the tooth surface. The large gear uses negative displacement, and the small gear uses positive displacement. After processing, it becomes a new gear pair with no change in transmission parameters, allowing the large gear to be repaired and put into use. [Example] In a metal processing factory, there is a large herringbone wheel that has been worn and scrapped, with Mn=16, Z=170, pitting on the tooth surface, and a pit depth of about 2-3 mm. After research, we have decided to carry out a highly modified repair of this large gear and manufacture a separate matching pinion. Thereby restoring the normal use of the gear pair.

3. Tooth inlay repair method: For gears with low load and low rotational speed, after individual teeth are removed, the root of the damaged gear is planed into a trapezoidal groove on a planer during repair, and a new tooth embryo with the same groove shape is pressed in with a certain degree of tightness, welded firmly or connected with bolts, and processed for shaping.

4. Surfacing repair method: For individual gear tooth wear or tooth end wear on both sides, one or more layers of metal can be overlayed on the entire or partial surface of the gear according to the gear damage situation. Repair welding of gears can be divided into electric welding and gas welding. Repair the gear by surfacing welding, which is easy to operate and has good repair quality.