Crank shaft for travelling planet wheel

The utility model relates to a crank shaft for a travelling planet wheel. The crank shaft comprises a main body; the main body comprises an outer spline, two thrust bearing shaft necks, two straight-ball bearing shaft necks and a shaft shoulder, wherein the two straight-ball bearing shaft necks are both eccentric shaft necks, the eccentric positions of the two straight-ball bearing shaft necks are symmetric about the central axis of the shaft shoulder; the two straight-ball bearing shaft necks are connected through the shaft shoulder; two sides of each straight-ball bearing shaft neck are respectively connected with a trust bearing shaft neck; and the thrust bearing shaft neck at one side of the main body is connected with the outer spline. The crank shaft has the beneficial effects that the design is novel, the structure is simple, the processing is convenient, the strength and the rigidity are greatly strengthened, the combining precision among all parts is improved, the service life of a system is prolonge