Motors for traction on railway trunk electric locomotives, industrial and mining electric locomotives, electric drive diesel locomotives and various electric vehicles (such as battery vehicles, urban trams, underground railway electric vehicles)
. Traction motors include traction motors, traction generators, auxiliary motors, and the like.
Traction motor A motor used to drive one or several moving axles on a locomotive or motor car. There are many types of traction motors, such as DC traction motors, AC asynchronous traction motors and AC synchronous traction motors. DC traction motors, especially DC series-excited motors, have better speed regulation performance and working characteristics, and are suitable for the traction characteristics of locomotives and have been widely used.
The working principle of the traction motor is the same as that of the general DC motor, but it has special working conditions: the space size is limited by the gauge and the diameter of the moving wheel; the locomotive runs through the rail and the ballast
It must withstand considerable impact vibration; when the large and small gears are badly engaged, strong torsional vibration will occur on the armature; in harsh environments, rain, snow and sand will easily invade. Traction
Motivation also has many requirements in design and structure. For example, to make full use of the internal space of the machine to make the structure compact, it is necessary to use higher-level insulating materials and magnetic conductive materials, and the parts need to have higher mechanical strength.
Degree and rigidity, the whole motor needs to have good ventilation and heat dissipation conditions and dust and moisture resistance. Special measures should be taken to cope with the difficult "commutation" conditions to reduce the sparks under the carbon brush.
There are two ways to suspend the traction motor. One is a suspension method in which the traction motor and the moving wheel shaft are connected, which is called a suspension shaft suspension or a semi-suspension. When using this suspension method, the moving wheel passes the rail
The impact vibration generated by the seam and the ballast is transmitted directly to the traction motor. The axle suspension is suitable for rolling stock with a structural speed of less than 120 km/h. The other is a frame-mounted suspension (or full suspension)
hang). When using this suspension method, the traction motor is fixedly suspended on the bogie frame, and various elastic connecting elements are added between the shaft end of the traction motor and the small and large gears to reduce shock vibration.
Impact. The pedestal suspension is suitable for rolling stock with a structural speed of more than 120 km/h.
When the traction transformer is stepped down by a silicon rectifier or a high-power thyristor, and the power is supplied to the DC series-excited traction motor, the voltage applied to the traction motor is a ripple voltage, so the pull
The induction motor is called a pulse traction motor. The "commutation" condition of high power pulse traction motors is more difficult. In addition, there are some additional losses inside the motor, which causes the motor to rise.
Therefore, the design and structure of the pulse traction motor must take certain special measures to solve the two outstanding problems of "commutation" and temperature rise.