DF28 tractor internal spline gear is the important part for the tractor power transmission and changing the speed.The workpiece material is 18CrMnTi steel, which is usually carried out carburizing quenching treatment.
In production, after gear carburizing quenching, the inner hole shrinks and deforms, and presents the oval, the waist drum shape and the cone shape shrinkage distortion. But our factory used the induction hardening equipment for internal spline gear induction quenching process, in order to solve its cone shrinkage defects, and it achieved good results.
Drum-shaped or tapered shrinkage of the internal spline gear is heated by induction hardening machine to 820 ℃ for induction quenching, and then to carry out water cooling on the gear hole wall with cooling time of 1-2s. So that its surface temperature dropped to Ms points below, then it's quickly quenched into the oil.
The use of induction hardening method has a good effect in repairing the shrinkage gears, which does not affect the variation of the gears and other technical indexes, and has no effect on the tooth surface and spline hole hardness. The induction quenching time can be controlled accurately and properly with this machine. In addition, the above method is used for the inner hole expansion of the inner spline gear, to repair the inner spline hole cone-shaped shrinkage distortion.