1. Adjustment transposition method
Change the orientation of the worn gear, and continue to work with the part of the gear that is not worn or slightly worn. It is suitable for repairing the gear transmission mechanism caused by unilateral wear of gear teeth due to unidirectional operation. For the gear with symmetrical structure and unilateral wear, it can be directly turned to 180 for reinstallation. For the gear with asymmetric structure, the asymmetric structure (non-gear teeth) that affects the installation can be removed, and the corresponding structure can be added at the other end by welding, riveting and other methods, and then turned over 180 for installation and use. It is also possible to add an adjusting washer on the shaft where the gear is installed, and adjust the gear to the correct position without increasing the structure, but it is best to turn it over in pairs or replace the matched gear with a new one to ensure the normal meshing of the gear. Bevel gears or forward and reverse gears cannot be repaired by adjusting transposition.
2. Displacement cutting method
We use the method of height modification to turn the outer diameter of the scrapped big gear to a certain value, and then re-hobbing to remove the pits on the tooth surface. The big gear is repaired negatively and the small gear is repaired positively. After machining, it becomes a new gear pair with unchanged transmission parameters, which makes the big gear be repaired and put into use. [Example] There is a worn-out herringbone wheel in the metal processing plant, Mn= 16, Z= 170, and the tooth surface has pits with a depth of about 2 ~ 3 mm After research, we decided to repair the height displacement of this big gear and manufacture a matching pinion. So as to restore the normal use of the gear pair.
3. Insert tooth repair method
For gears with small load and low speed, after individual gear teeth are knocked out, when repairing, the root of the bad gear is planed out of the trapezoidal groove on the planer, and the new gear blank with the same groove shape is pressed in with a certain tightness, welded firmly or bolted, and processed and formed.
4. Surface repair method
Individual gear teeth wear or tooth end wear exceeds the limit, etc. According to the damage of the gear, one or more layers of metal can be surfacing on the whole or part of the gear surface. The welding repair of gears can be divided into electric welding and gas welding. Repairing gears by surfacing welding is simple in operation and good in repair quality.
5. Gear ring inlay repair method
Wear of gear teeth can be repaired by replacing the gear ring. First of all, all the teeth of the gear that need to be repaired are turned out, and then a gear ring is manufactured and press-fitted on the parts of the teeth. In order to prevent the new gear ring from loosening, it can be fixed by spot welding along the circumference at the joint between the gear ring and the gear, or by drilling holes and driving stabilizing nails. The 600mm gear used in the winch of our foundry is made of HT200. After two teeth were knocked out, neither surfacing repair method nor screw tooth making method can meet the use requirements. After analysis and research, it is decided to adopt the method of setting a gear ring, recast a gear ring, and change the material to ZG45, which improves the service strength of the gear and has a good effect in the process of use. 3.6 Remove the worn gear by spiral tooth-making method, clean it, measure the thickness of the tooth root with vernier caliper, and smooth the tooth-lost part with trowel and clean it. Select the screw with corresponding diameter according to the thickness of the tooth root, and the thread length shall not be less than 1.5 ~ 2 cm. Then use a bench drill to drill a hole with the same diameter as the screw in the tooth-dropping part of the gear, and then tap. Tighten the selected screw in the screw hole, then saw off the screw above the top of the tooth with a hacksaw, and then use a broach to process it into a tooth with the same tooth shape as the original tooth.