According to the voltage level, the high-voltage motor adopts various specifications of winding flat wires, such as bisimine, monoimine, thin double-stranded wire and so on. After the materials are prepared, they can be wound into shuttle rings on the winding machine. Generally, the shortest straight part of motor coil is 25cm, and the largest straight part is1.2m. The winding can be single flat winding, single vertical winding, double flat transposition winding or double flat transposition vertical winding, which is determined according to specific requirements.

2. Dressing before molding

After the high-voltage motor shuttle coil is wound, it is wrapped with insulating materials such as shrink tape and yellow wax tape to protect the external insulation, interlayer insulation and turn-to-turn insulation of the coil from being damaged. When pulling the machine, it is not rubbed by the mold fixture and the nose pin to prevent looseness and deformation.

Three. cast

Forming machine, expanding machine and wire drawing machine are actually a kind of machine, whose main purpose is to draw vertical shuttle coil or flat shuttle coil wound by winding machine into frame coil. The frame coil is based on the inner and outer circles of the motor stator core to form a centripetal angle coil. It takes two technicians to wind the shuttle coil, but generally it takes three people to pull (unfold).

Before there was a molding machine, there were several experienced masters in our office who could draw 72 coils in 15 minutes, but it was a little difficult to draw larger coils.

Generally, three people can pull out 72 coils in one hour with a wire drawing machine. The longest straight part of each molding coil can be adjusted to 1.5m, the height can be adjusted within 80cm, and the angle adjustment range is 0-60 degrees. Four clamps can realize universal locking.

Plastic operation

Due to the addition of different layers of mica insulation materials, the thickness of the high-voltage motor has increased a lot, and the distance between the ends of the coil has been squeezed by the insulation layer. If you don't pay attention, it will not fit in when you bury the wire, which makes it difficult to bury the wire. This requires cold forming. Traditionally, cold forming dies (or male dies) are mostly made of wood, so each type of motor needs to make a set of dies.

5. Bind mica tape and hot press.

The stator coil enters the winding process after cold forming, and the materials with high insulation level of the coil are basically localized, but the quality and price of mica materials are very different. Different grades of mica and other materials have different subscription standards due to different voltages and seasons. A female worker winds the coil 10 hour a day, and a 10000 volt coil with a frame coil circumference of 2 meters is expected to wind three times.

Hot presses can be equipped with automatic control devices, such as how many degrees of H-class temperature work at constant temperature, how many degrees of F-class temperature work at constant temperature, how many factories have hot pressing time, when to start up and when to stand by and keep warm. When hot pressing, you should bring your own tools such as release agent, scavenger and slag removal from the designated manufacturer.

6. Test the withstand voltage

After the hot-pressing coil is demoulded, it should be left for a period of time before testing the pressure resistance. This is a process of testing products. According to different working voltages such as 3000V, 6000V and 10000V, the withstand voltage standard is set according to different requirements.

7. Embedding (stator, rotor)

The stator and rotor of the motor are dusted (generally cleaned with a high-pressure water gun) and then put into the oven for baking. After cooling, decide whether to repair or overhaul the motor. When repairing the high-voltage motor, there is a set of coil tools, rotor wire bending tools and stator coil motion hot pressing tools. There are many similar gadgets that need to be made by yourself. The key is to combine technology with experience.

How not to damage the primary coil is the key. It is time-consuming and laborious to take out the coil and reprocess it. Whether the old coil can be rebuilt is the key to saving time (generally, the procurement cycle of winding used in high-voltage motors is 1~2 weeks, which delays the repair time. These important issues need to be mastered in the follow-up research).

Eight. pour into

When motor manufacturers mass-produce motors, they need to buy vacuum dipping equipment, which is provided by professional manufacturers. Generally, repair shops use electric heating rods to heat the stator to a certain temperature and then turn it over, with the stator mouth facing up for double-sided painting. There is a paint container at the bottom when painting. After painting, it takes more than two hours to put it in the oven. First, it is dried at low temperature for three hours, and then at high temperature 18 hours. After a total of 24 hours, it will be released.

The purpose is to solidify the insulation between the bars and wires inside and outside the tank and prevent vibration from damaging the insulation structure. Please remove the residual paint in the stator cavity for assembly.

Nine. Experiment?

Parameter test of the whole machine: the self-owned patented technology-magnetic control switching transformer startup test equipment is used to start various motors such as 380V, 660V, 1 140V, 3000V, 6000V, 10000V, and the high and low voltage startup test capacity is within 1000KW.

All squirrel-cage and slip-ring motors can be used for no-load starting and no-load running tests. The test items include measuring current, voltage, speed, temperature and noise.

Extended data

The main purpose of hot pressing is:

1, which is convenient for line embedding after setting.

2, coil curing can be moisture-proof and waterproof. ?

3, corona discharge to the gap. ?

4, complete the closed to the outside world, to avoid high voltage breakdown.

References:

Baidu Encyclopedia-High-voltage Motor Maintenance Process and Standard