A welding system including a welding electrode, a closed-loop cooling device, and a vent. The closed-loop cooling device is configured to cool the welding electrode. The closed-loop cooling device includes a pump and a water line. The vent is located along a path of the water line. The vent is configured to release air trapped within the water line.

The seam welder conductive mechanism is the main part of the resistance seam welding machine. When the electrode wheel rolling on the welded parts, the Seam welder conductive mechanism will withstand the high press of electrode force and pass the high welding current from welding transformer to the electrode wheels of seam welding machine. Because of these two characteristics the following factors must be considered during the design of seam welder conductive mechanism. First of all, in order to withstand the high press of electrode force two bearings are introduced in the mechanism, the bearing should be lubricated and also isolated from the welding current in order to get long working time without damaging the bearing. Second of all, in order to pass the high welding current, the conductive pair with relative motion must be keep conduction all the time with certain surface pressure and lubrication, the conductive pair without relative motion must be keep conduction all the time with big surface pressure. Because of the high current pass through the conductive mechanism must be cooled with water during working. This is a mechanism equipped with water cooling for Electrode, main shaft, and Silver-plate conductive pads.

A welding system including a welding electrode, a closed-loop cooling device, and a vent. The closed-loop cooling device is configured to cool the welding electrode. The closed-loop cooling device includes a pump and a water line. The vent is located along a path of the water line. The vent is configured to release air trapped within the water line.

An arrangement including a welding arm (2) for a resistance seam welding machine and a roller head (1) fastened thereon, which has a stator (3) and an electrode roller (4) which is supported as a rotor on the stator (3) in a rotatable way, wherein the stator (3) protrudes over the electrode roller (4) with fastening extensions (5) on both sides of the electrode roller (4). The welding arm (2) has a reception opening (6) for the roller head (1), which is formed between two limiting walls (7) facing each other, which themselves have fastening reception openings (8) for the fastening extensions (5). The roller head (1) is arranged inside the reception opening (6) in such a way that the electrode roller (4) protrudes outside the reception opening (6) with a part of its circumferential boundary and the fastening extensions (5) are arranged inside the fastening reception openings (8). The roller head (1) is fastened to the welding arm (2) by pressing each of the fastening extensions (5) of the stator (3) with an even contact surface (9) formed thereon to a attributed even contact surface (10, 19) inside the boundaries of the respective fastening reception opening (8), wherein each of the fastening extensions (5) of the stator (3) is pressed with a clamping piece (11) received in the respective fastening reception opening (8) with its contact surfaces (9) against the attributed contact surfaces (10, 19). It has been discovered that mounting errors may be avoided by the arrangement according to the invention and that a good and reliable sealing and current transmission can be reached.

With a roller head (10) of a resistance seam welding machine, which roller head has a stator (12) and a rotor (14), the bearing outer housing (18, 18) is cooled by means of channels (2, 2) provided in its interior. This increases the life of the roller head.