The choice of high-quality planetary gear reducer materials is conducive to improving its carrying capacity and service life.
Due to the structural and load characteristics of the gearbox, quenching gears should be widely used. There are many heat treatment methods for hardened gears. According to the characteristics of the gear reducer can choose surface quenching, overall quenching, carbiding quenching, nitriding quenching and so on.
First, the surface hardens.
Common surface quenching methods are high frequency quenching (for pinions) and flame quenching (for large gears). After quenching on the surface of the hardened layer, including the root of the tooth, the effect is better. The face hardness can be up to 45-55HRC.
Second, nitriding.
Nitrogen treatment ensures that the gears have high hardness and wear resistance in smaller deformations. After heat treatment, can not be well refined, so as to improve the carrying capacity.
Third, carbon permeation after hardening.
Heat treatment quenching gears have relatively high carrying capacity, but in order to ensure accuracy, grinding (grinding teeth) must be used to eliminate heat treatment deformation.
Carbon seepage and hardening are commonly used in alloy steels with a precarbonization carbon content of 0.2%-0.3%. The hardness of the teeth is generally between 58 and 62HRC. Under 57HRC, the strength of the hard surface will decrease significantly, above 62HR, the strength of the hard surface will decrease significantly, and the strength of the hard surface will decrease significantly. It is found from the calculation that the hardness of the quenching gear is gradually decreased from the tooth to the depth, and the effective carbon permeable depth is 5.25HRC, which penetrates from the tooth to the hardness.
Heat treatment quenching not only improves the hardness of the casting, but also enables the casting surface to produce residual pressure stress, thereby increasing its anti-bend fatigue strength. The stress of the high-pressure shrinkage area can be reduced so that the root of the tooth cannot be ground during the grinding process.