Choosing a good planetary gear reducer material will help improve its bearing capacity and service life.
In view of the structural characteristics of the Galaxy reducer and the load characteristics of the gear, hardened gears should be widely used. There are many heat treatment methods to obtain hardened gears. Such as surface quenching, overall quenching, carburizing quenching, nitriding, etc., should be selected according to the characteristics of the gear reducer.
1. Surface hardening
Common surface quenching methods include high frequency quenching (for small-size gears) and flame quenching (for large-size gears). When the hardened layer of surface quenching includes the bottom of the tooth root, its effect is good. The tooth surface hardness can reach 45-55HRC.
Nitriding can ensure that the gear can achieve high tooth surface hardness and wear resistance under the condition of small deformation. After heat treatment, no good finishing is performed, which improves the load-bearing capacity.
Three, carburizing and quenching
The carburized hardened gear has a relatively large load-bearing capacity, but the finishing process (tooth grinding) must be used to eliminate heat treatment deformation to ensure accuracy.
Carburized and hardened gears are commonly used in alloy steels with a carbon fraction of 0.2%-0.3% before carburization. The hardness of the tooth surface is often in the range of 58-62HRC. If it is lower than 57HRC, the hard surface strength will decrease significantly, and it will be brittle if it is higher than 62HR. increase. The hardness of the carburized hardened gear gradually decreases from the surface of the gear to the deep layer, and the effective carburizing depth is specified as the depth from the surface to the hardness of 5.25HRC.
The effect of carburizing and quenching on the bending fatigue strength of gears not only increases the hardness of the core, but also lies in the residual compressive stress on the surface. It can reduce the stress in the high compressive stress area, so the root part of the tooth cannot be ground during tooth grinding.