The differential planetary gear shaft is responsible for transmitting torque to the planetary gears, which enables torque distribution and allows the wheels to perform differential operation.

Introduction
The product is offered in both integral and split styles.
To guarantee adequate lubrication between the planetary gear and the planetary gear shaft, a flat surface is milled onto the journal for lubrication.
Quality requirements
When using low carbon alloy structural steel, carburization and quenching should be performed to achieve a carburized layer depth of 0.8-1.4 mm and a journal surface hardness of 58-64 HRC.
For medium carbon or medium carbon alloy structural steel, induction hardening should be utilized, with the journal surface hardness no less than 57 HRC. The hardened layer depth should be 1.2-2.5 mm (shaft diameter d ≤ 20 mm) and 1.7-4.0 mm (journal diameter d > 20 mm). Additionally, the journal root radius must also undergo hardening.
In terms of appearance quality, parts must be free of defects such as nicks, black spots, and cracks. Furthermore, burrs, flash, and non-machined surfaces must be removed.
The surface roughness of the journal should be no greater than 0.5 μm, while the surface roughness of the journal root should not exceed 3.2 μm.
Geometric tolerance requirements are as follows:
a) For integral differential planetary gear shafts, when referring to the common axis, the shape and position tolerances of the relevant parts are specified as follows: the full runout tolerance of the journals at both ends should be no less than 9, the perpendicularity tolerance level of the two common axes should be no less than 8 levels, and the two common axes must be in the same plane with a positional tolerance of no more than 0.10 mm.
b) For the split differential planetary gear shaft, the straightness tolerance of the journal busbar should be no less than 8 levels.