The V-shaped roller rolls on the V guide welding machine of the roller, and the V-shaped guide surface of the roller is hardened and ground to ensure strength and transmission accuracy. The V-shaped roller rolls on the V-shaped guide rail of the roller and the linear speed can reach up to 10m/s. The rolling ball-bearing steel ball or tapered roller of the HEPCO roller does not directly contact the guide rail, which prevents the pollution on the guide rail. The object contacts the rolling elements while the bearing has a good sealing property to prevent contaminants in the air from entering and contacting the rolling elements. The contact between the V-shaped roller and the high quality v guide welding machine is a line contact, and the line is obliquely intersected with the central axis of the roller, and rotates at a high speed around the central axis; the contact between the wire and the V-shaped guide surface of the roller belongs to instantaneous contact, and the high-speed approaching the guide rail Face, instantaneous contact, and then leave at high speed; in this case, the "wire" of the V-shaped roller of the roller is continuously "scratched" on the surface of the guide rail, which can ensure the cleaning of the guide surface.