Roller for omni-directional wheel

The invention relates to an omni-direction wheel, in particular to a roller for an omni-directional wheel. The roller for the omni-directional wheel comprises a rolling wheel, the rolling wheel comprises a rolling wheel outer sheath and a rolling wheel body, the outer diameter of the middle part of the rolling wheel is larger than those of two ends of the rolling wheel, the rolling wheel outer sheath is arranged on the outer layer of the rolling wheel body, two ends of the rolling wheel body are respectively provided with a bearing cavity serving as a shaft hole simultaneously, the rolling wheel body is internally provided with a hollow cavity which is sealed when both the bearing cavities at two ends are sealed, and each bearing cavity is provided with an internal boss in which a shaft hole is arranged. The outer edge of the rolling wheel adopts a track of an involute, in this case, the rolling wheel projects a circular counter line on the side face of a hub, and owing to the arrangement of the hollow cavity