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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 worm gear reducer, which drives the winding machine to realize 0- 120 rpm forward and reverse braking and can count forward and reverse. Generally, all kinds of motor coils within 1600KW can be wound, and a set of simple tensioners can be equipped to control the tightness of the wound coils.
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.
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.
5. Bind mica tape and hot press.
That is, after the stator coil is cold-formed. 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. Mica tape, high stopband, shrinkage tape as to what role they play in the coil, which one is of good quality and low price, how to wind it, where to wind it, how many layers to wind it, and so on. 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. is set to facilitate rule embedding.
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.
Electric vehicle motor maintenance technology 1. There are windings and magnetic steel (magnetic poles composed of permanent magnets) in the motor. When current is introduced into the winding, a magnetic field will be generated. This magnetic field interacts with the magnetic field of the magnet to make the rotor rotate.
Second, generally speaking, the speed of the motor is related to the structure of the motor and the external voltage. The more turns of the coil, the slower the speed, and the fewer turns, the faster the speed. The weaker the magnetic field strength of magnetic steel, the larger the air gap between stator and rotor, the faster the speed, but the smaller the torque. The higher the voltage applied to the motor, the faster the speed.
Three, brush low-speed motor maintenance procedures
1, turn off the power.
2. Turn the motor by hand. Under normal circumstances, the forward rotation is easy without jamming, and the reverse electromagnetic resistance is uniform.
3, brush fault judgment method: reverse motor, if the electromagnetic resistance has obvious changes (sometimes tight, sometimes loose), indicating poor brush contact, you can use the resistance file to detect the on-off situation of the coil for further detection.
4. Judgment method of magnetic steel fault: If the electromagnetic resistance of the reverse motor is obviously small, it means that the magnetic steel is demagnetized (or the magnetic steel is wrongly arranged), and if necessary, it is further tested to see if the no-load current is too large.
5. Short-circuit fault phenomenon of coil: (disconnect the motor from the controller)
(1) When the motor wires are separated, the forward rotation, reverse rotation and motor have obvious electromagnetic resistance.
(2) The motor wire is short-circuited with the motor housing (excluding disconnection and grounding)
(3) When the motor circuit is short-circuited, the electromagnetic resistance has no obvious increase compared with that when it is open.
(4) The motor wire is short-circuited, rotating forward and backward, with no or very weak electromagnetic resistance and large no-load current.
(5) Use a multimeter with a voltage range of 20V to detect the power generation of the motor, and judge that the motor has no voltage or extremely low voltage as a short circuit.
Four, the repair method of brush motor
(1) Standards for replacing brushes and brush holders:
A, the brush must be completely consistent with the brush grip: flexible, without jamming and excessive shaking.
B, brush lead should be long enough, so that the brush can completely come out from the brush holder.
C, the elastic force of the brush spring should be large enough, and the two elastic forces should be uniform.
D, brush grip should be aligned. Observe the principle of five points and one line.
(2) Cleaning of commutator
A, first use sandpaper to polish the commutator surface, and polish the uneven commutator more.
B, use hacksaw to take out the carbon deposit in the commutator slot, and re-polish the commutator.
C, clean the dust and impurities inside the motor.
(3) Maintenance of magnetic steel
A, use magnetic steel to detect whether the magnetic field strength and polarity direction of each piece of magnetic steel are normal and record.
B, magnetic steel with weak magnetic field must be replaced with the same polarity and size.
C, magnetic steel arrangement sequence is wrong, should be rearranged and cemented.
The correct use of DC motor ① When the DC motor is directly started, it will have a great impact on the power supply and the motor itself because of the large starting current. Therefore, except for low-power DC motors, general DC motors should take decompression measures to limit the starting current.
(2) When the 2)DC motor is started with reduced voltage, it is necessary to master the time required for the start-up process, not to start too fast or too slow, and to ensure that the start-up current is not too large (generally 1 ~ 2 times the rated current).
(3) When the motor is started, the corresponding stop preparations should be made. Once an accident occurs, the power supply should be cut off immediately to find out the cause of the failure.
④ When the DC motor is running, observe whether the motor speed is normal; Whether there is noise or vibration, etc. Whether there is smoke or burning smell, etc. If yes, stop the machine immediately to find out the reason.
⑤ When the DC motor is running, observe the sparks on the surface of the brush and commutator. Under the rated load condition, General DC Motor Company only allows the spark not to exceed 1 1/2.
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