Welding head for seam welding metal sheet - where planetary gear trains force conducting grease to electric contact surfaces

摘要

Seam resistance welding head for welding metal sheets uses a welding roller mounted on the end of a shaft located in roller-bearings in a housing filled with an electrically-conducting grease and with a device for feeding the grease to the contact surfaces of the shaft. Shells transmit the electric current, the shells being pressed onto the shaft by spring-loaded conductor-straps. The device used to feed the grease consists of =1 disc with peripheral teeth and fitted with spiral blades. The disc(s) is/are able to rotate on the shaft and is/are driven by a planetary gear which is rotated by a gear-ring with internal teeth fixed to the bore of the housing. The disc gear rotates at a higher speed than the welding roller due to the planetary gear train and thus forces the conducting grease along the contact surfaces, improving conduction and reducing friction.