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. Circular enameled wire coils can also be wound by using a universal regulator in the disc. The winding machine is equipped with a speed regulating motor and a turbo-rod reducer, which drives the winding machine to rotate at the speed of 0- 120 rpm and can count up and down. Generally, all kinds of motor coils within 1600KW can be wound, and a simple tensioner is equipped to control the tightness of the wound coil. General maintenance manufacturers can choose the above products. If they encounter particularly large specifications, they can choose.
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.
Generally, female workers are used to tie coils. Because they are careful and work fast, usually 3-5 people tie coils to draw pictures. You can also use an electric tape winding machine.
Three. cast
Forming machine, expanding machine and wire drawing machine are actually a kind of machine. Its main purpose is to draw a vertical winding shuttle coil or a flat winding shuttle coil wound by a winding machine into a frame coil. The frame coil is based on the inner circle and the outer circle of the motor stator core to form a centripetal inclined 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. General manufacturers, such as a motor factory in Harbin and a branch factory in Xiangtan. , bought this manual plotter. The overall evaluation is that the production seems simple, but the operation is flexible and convenient. It is a practical product with quick demoulding, convenient drawing, accurate positioning and accurate angle adjustment. Before drawing, according to the actual situation of the repaired motor, draw the shape of the coil with a computer and make it into a template to adjust the wire drawing machine. Those who can't draw generally use old coils as templates to adjust the drawing machine. The four clamps of wire drawing machine have up, down, left and right adjusting mechanisms, and the adjusting clamping mechanism locks the coil to enter the drawing process. The electric wire drawing machine produced by our company is almost the same as that produced in Shanghai. They are all around 90 thousand yuan. If it is practical, the price of electric wire drawing machine is 25,000 yuan and that of hydraulic wire drawing machine is 26,000 yuan. This molding machine is made in China. Manufacturers in Shanghai and Shenyang mainly consider large generators, but the operation is complicated, mainly including angle adjustment, movement, distance adjustment, height adjustment, inflexible wire clamping and relatively expensive.
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 motor needs to make a set of dies, and the male dies used by our company have the flexibility to adjust the distance, angle and end. Attention must be paid to knocking during normal molding, so as not to destroy interlayer insulation.
After the low-voltage motor is led out, it is generally not cold-formed, and directly enters the assembly process.
5. Bind mica tape and hot press.
After the stator coil is cold-formed, it enters the winding process. At present, the materials with high insulation grade of coils are basically made in China, but the quality and price of mica materials are quite different. Our company has been making coil and winding high-voltage motors for many years and is familiar with the quality and price of more than a dozen products. Students will inform the manufacturer of the specific situation after graduation. 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. How many layers of coils of various motor brands are wrapped, whether straight lines are wrapped first or ends are wrapped later, depends on when wires are embedded. As for the function of mica tape, high stopband and shrinkage tape in the coil, which is of good quality and low price, how to pack it, where to pack it, how many layers to pack it, and so on. It is best to master and remember the essentials in the next study. Our company produces universal mica tape winding machine. Generally, a tape winding machine can replace 3-5 people to work, and manufacturers who mass-produce coils can choose. Customers who are repairing large motors for the first time, it is better to wrap them by hand when repairing them for the first time. When repairing high-voltage motors, generally, the following steps should be carried out at the same time: winding, traction, cold straightening, mica tape wrapping and high-low gear wrapping. These processes need 2-3 people to operate. At the same time, the next hot-pressing coil process should also be started. The main purpose of hot pressing is: 1. Convenient rule embedding after setting.
2. Curing of the coil can be moisture-proof and waterproof.
3. Corona discharge outside the notch.
4. Complete sealing to the outside to avoid high voltage breakdown.
The length of the hot-pressing molding machine produced by our company is1.2m, and the angle can be adjusted up, down, left and right. After the customer has a fully automatic computer-controlled hot press, it can process stator coils of YR, JR, JS and TDK and motors within 1600KW. And can be customized according to customer requirements.
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.
How to prevent the straight part or the curved part from being punctured and cracked is something that must be mastered during hot pressing. Our company has mastered some skills to repair the coil of high-voltage motor, and the skills to copy the coil after it is broken down and withstand voltage need to be learned for a period of time.
For pressure instruments, there are generally many products in Wuhan.
From winding the coil to embedding, it is usually necessary to make an extra coil for the following purposes:
1. Leave the technical data of this type of motor (wire diameter, turns, insulation thickness, straight line length, curvature, end length, lifting height, pitch angle, etc.). ).
2. If the coil is unqualified, please replace it.
High-voltage motors are generally 200 kW-2000 kW and weigh more than 3 tons. Suitable cranes can be designed according to their own conditions to facilitate motor maintenance.
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).
During minor repairs of the rotor, a series of procedures, such as how to take out the copper bars (aluminum bars) in the rotor, how to change the bars when taking out, how to make standard coils by bandaging, and how to conduct welding tests, are not discussed here. When overhauling the motor rotor, all coils must be taken out. How to get them and how to keep them in good condition is the key technology. For example, the high-voltage motor should be taken out as completely as possible. If the measuring tool is not damaged, you can save money and time when repainting. When the coil needs to be remade, it is a waste of time to calculate the wire gauge. When embedding the stator wire, it is usually pressed once every three coils to prevent the coils from discharging to the notches at both ends or the end rings at both ends, and the coil is damaged and discharged due to offline errors. The wiring, spacing, grouping, wiring, bandaging, star connection and lead-out after the whole coil is embedded are all carried out in accordance with the operating procedures of various grades of motors. Generally, the motor is sealed together after passing through a withstand voltage before the star sealing point, and three leads can be drawn out. There is also a special lead that connects the six leads into a triangle or star line. General leads need to be purchased from designated high-voltage cable manufacturers. After all the embedded wires are connected, the whole motor is completed after one withstand voltage.
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: our company adopts its own patented technology-magnetically controlled switching transformer to start the test equipment, and starts various motors such as 380V, 660V,140 V, 3000V, 6000V, 10000V, etc., and the high and low voltage start-up test capacity is1. 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. Source: