Usually speaking of the composition of transformer winding machine, we all know that there are winding mechanism, wire routing mechanism, cutting machine, coil mold, release mechanism, heating mechanism, tensioning mechanism, frame and so on. The winding machine slip ring is also an important component, if the winding machine slip ring heat causes the equipment to stop working, the impact is also very great, the following is to analyze the characteristics and maintenance of the winding machine slip ring:
1, winding machine slip ring structure and principle
The slip ring of NC winding machine is composed of conductive ring, tail brush, brush handle, conductive rod, collector ring and slip ring cover. The windings of the rotor are similar to those of the stator. The three phase windings are connected in a star shape. The starting point of each phase winding is connected with three copper slip rings, which are fixed on the rotor shaft. The rings and shafts are insulated from each other and connected to an external circuit by a series of spring-fed carbon brushes.
2. The generation and development process of slip ring heat
When the magnetic ring winding machine is in normal operation, the temperature of the carbon brush is generally between 50℃ and 80℃ (the temperature rise is about 40℃), and the working current of each carbon brush is between 20A and 100A. Brush handle spring pressure is more uniform, carbon brush movement freely, no vibration phenomenon. The heat generated by the brushes and slip rings is taken away by the ventilation system. That is, there is a basic equilibrium between heat and heat. However, when the carbon brush becomes short, the contact resistance and additional resistance become larger, and the brush handle spring pressure becomes smaller. If the working current increases, the balance capacity of the system will decrease with the change of temperature, and the temperature of part of the carbon brush will increase, so the temperature of the whole system will increase.
3. Cause analysis of slip ring heat
Slip ring cooling air volume is not enough. The axial installation of the fan blade with slip ring shall be accurate in orientation and conform to the structural design standards and regulations. On the one hand, it will cause bearing vibration, on the other hand, the cooling air volume of the slip ring is not enough to heat the slip ring and brush.
