Surface treatment process of planetary gear reducer

Choosing high-quality planetary gear reducer materials will help improve its load-bearing capacity and service life.

Considering the structural characteristics of the Galaxy reducer and the load characteristics of the gears, hardened gears should be widely used.There are many heat treatments available to obtain hardened gears.Such as surface quenching, overall quenching, carburizing and quenching, nitriding, etc., should be selected according to the characteristics of the gear reducer.

1. Surface hardening

Common surface hardening methods include induction hardening (for small gears) and flame hardening (for large gears).It works well when the case hardened layer includes the bottom of the dedendum.The tooth surface hardness can reach 45-55HRC.

2. Nitriding

Nitriding can ensure that the gear can achieve high tooth surface hardness and wear resistance under the condition of small deformation.After heat treatment, good finishing cannot be done, which increases the load carrying capacity.

Three, carburizing and quenching

Carburized and quenched gears have a relatively large load-bearing capacity, but finishing (grinding) must be used to eliminate heat treatment deformation to ensure accuracy.

Carburized and hardened gears are usually used in alloy steels with a carbon content of 0.2%-0.3% before carburizing.The hardness of the tooth surface is usually in the range of 58-62HRC.If it is lower than 57HRC, the hard surface strength will be significantly reduced, and if it is higher than 62HR, the hard surface strength will become brittle.Increase.The hardness of carburized and quenched gears gradually decreases from the surface to the deep layer of the gear, 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 reduces stress in areas of high compressive stress, so the root of the tooth cannot be ground during the grinding process.