Traction drive production
Siemens traction drives are manufactured at the Nuremberg converter and motor plant where they pass through all phases of production – from machining of housings, to coil winding and rotor production, all the way to assembly and testing. A total of 3,600 traction motors leave the factory each year.
The vehicles use both motors with welded design and motors with casted housings. The laminated stator core of motors with welded design also serves as the motor's external casing. This requires that the tie rods and other components be welded on. The housings of enclosed motors are machined at the machining center in order to achieve the requisite dimensions.
Each year at our plant, 11,000,000 laminations are punched from around 14,000 tons of insulated electric sheets using presses that provide up to 400 tons of punching force. Specialized devices assemble the punched laminations into stator and rotor cores.
Fixtures are used to process the electro copper needed for the winding into the necessary form. This involves drawing machines that draw the copper into shape. The copper coils are wrapped in fiberglass and/or Kapton tape for the purpose of electrical insulation. Through a suitable selection of tapes, motors can be equipped for the different voltage classes.
The next step is to insert the prefabricated, insulated coils into the laminated cores and then connect the coil ends to the finished winding.
Our team uses a vacuum pressure impregnation system to impregnate the windings with a special resin that fills all the gaps and makes the winding impervious to environmental influences. In the case of enclosed motors, the assembled laminated core is pressed into the housing.
Next, we shrink-fit the stacked core onto the rotor shaft. The rotor bars are then inserted, caulked and skimmed and the end rings soldered. Before assembling the drive, our team dynamically balances the rotors so that they run quietly and evenly.
We now insert the rotors and attach the end-shield, temperature sensor and pulse generator. Depending on the drive version ordered, pinions and gears are also mounted.
Every motor and every finished drive then undergoes a computerized test program to verify that its components are functioning correctly. After testing, the motors are painted and packed for shipment.