Method for repairing solder joint leakages and welding or soldering apparatus for carrying out the method

A method for repairing solder point leakages on a connection apparatus configured to introduce cooling water into hollow metallic stator bars of a stator winding of an electric machine, wherein the connection apparatus has:

• a metallic bar-receiving body with a through-opening in which the stator bars are pushed, aligned using metallic spacers and connected in a materially bonded and fluid-tight manner to the bar-receiving body and to the spacers using a solder, wherein free ends of the stator bars terminate substantially flush with free ends of the spacers and with an end face of the bar-receiving body, a cup-shaped metallic covering element, which is connected in a materially bonded and fluid-tight manner to the bar-receiving body so as to enclose the free ends of the stator bars to form a cooling-water chamber;
• and a metallic cooling-water line connector, which is provided on the covering element and fluidically connected to the cooling-water chamber, the method comprising:
• a) removing the covering element from the bar-receiving body,
• b) aligning and fastening a welding or soldering apparatus, which has a processing head movable in x, y and z directions, on the electric machine in such a way that the processing head is positioned radially outward from the bar-receiving body, wherein the fastening is effected in particular to a region of the electric machine that is arranged radially inward from the bar-receiving body;
• c) overwelding or oversoldering solder points which have become accessible as a result of removing the covering element and connect the stator bars, the spacers and the bar-receiving body to one another in a materially bonded manner,
• d) removing the welding or soldering apparatus, and
• e) fastening the covering element removed in step a) or a new covering element to the bar-receiving body in a materially bonded and fluid-tight manner.