Method for repairing stator winding bars

A method for repairing a connecting device for the electrical connection and for supplying and carrying away the coolant to and from the conductor elements of the stator winding bars of electrical machines, at least some of said conductor elements being hollow, all the conductor elements being surrounded by a metallic component and being soldered thereto and to one another, which component overhangs the conductor elements forming a water chamber and ends in a connecting fitting for coolant supply and carrying the coolant away, comprising the following method steps:

• a) inductive heating and removal of the existing connecting device from the bar end;
• b) cleaning the bar end in the region where the new connecting device is intended to be mounted;
• c) material-cutting machining the end surface of the bar end;
• d) introducing narrow slots between adjacent conductor elements into the end of the bar in the transverse direction and vertical direction;
• e) pushing on a first connecting part which is made of copper and completely surrounds the bar end;
• f) filling remaining gaps between the first connecting part and the outer surfaces of the bar end with copper foil and/or solder foil;
• g) filling the narrow slots, which have been introduced into the end of the bar, with copper foil and/or solder foil or a combination of both;
• h) inductive heating of the first connecting part and of the bar end and soldering with the addition of solder;
• i) at least visual inspection of the solder joint thus created;
• j) fitting a second connecting part made of copper to the free end surface of the first connecting part by soldering;
• k) testing the sealing of the resulting connecting device.