Roller device

A roller device, the device comprising:

• a roller;
• and
• a roller axle, the roller axle comprising:
• an axle portion configured to mount the roller such that the roller is rotatable about the axle portion;
• and
• a riveting portion at a mounting end of the roller axle, wherein the mounting end of the roller axle is one of the two ends of the roller axle along an axial direction of the roller axle, and the riveting portion extends from the mounting end in a direction away from the axle portion, wherein the riveting portion comprises, at its free end, an inclined surface, a contact end surface, and a fillet surface extending from the inside to the outside, and the radial width of the fillet surface is smaller than the radial width of the inclined surface;
• and wherein, when the roller device is pressed against a carrier under force, the riveting portion can pierce the carrier such that the roller axle is riveted with the carrier through the riveting portion;
• wherein the riveting portion and the axle portion do not overlap with each other in the axial direction of the roller axle;
• wherein the axle portion comprises an annular positioning mechanism extending around the axle portion, wherein the annular positioning mechanism is configured to prevent the roller from moving in the axial direction.