The motor weaving process must be understood and clearly defined
The market economy is a very good macro project, breaking the monopoly under the planned economy, all enterprises can compete on the same platform, of course, the motor market is no exception. Everyone who knows the motor knows that the winding is the heart of the motor, and the craftsmanship and details are the key to ensuring that the heart can beat healthily. The same scheme, the quality of different manufacturers of different processes will have great differences.
1. winding bulk technical requirements
Winding bulk includes the process of mounting a coil or conductor into a core slot, arranging and tightening the ends of the coil, and coupling the individual coils into windings, or coupling the coils to the commutator. Whether soft winding or hard winding, generally meet the following technical requirements:
(1) The pitch (or slot) of the winding, the connection method, the relative position of the lead and the outlet hole or the commutator must be correct. The soft winding wound into the slot must be accurate.
(2) The insulation is good and reliable. The quality and structural dimensions of the insulation material shall be in accordance with the regulations. In the bulk process, the insulation of the notch and the edge of the ventilation groove is most vulnerable to mechanical damage, resulting in high-voltage breakdown accident; the nose and corner insulation are susceptible to sprains, causing short-circuit faults between the turns, and special attention should be paid when inserting.
(3) Both ends of the winding should be symmetrical. The length and inner diameter of the end extension must conform to the regulations. If the size is too large or too small, it will affect the ventilation cooling effect and increase the winding temperature.
(4) The inside of the winding slot and the end extension must be fastened to prevent the winding from being moved by electromagnetic impact or centrifugal force (rotor winding), causing insulation damage. The wedges are required to be aligned and not to protrude.
(5) The joint should be welded well to avoid accidents such as overheating or breakage.
(6) When inserting, it is necessary to prevent iron filings, copper ends or welding slag from being mixed into the windings.
2. Preparations before windings are embedded
Preparations for windings before bulk, including preparation of tools, materials and wire drawings, preparation of insulation materials and slot molds, and cleaning of cores.
The hand-made line tool is relatively simple, and there are commonly used crimping plates, cable management boards, grooved wedge tools, curved wrenches, and the like. All tools in contact with the coil must be rounded and smooth to avoid damage to the insulation.
The specifications and dimensions of the insulation materials shall comply with the drawings. Insulation preparations include shearing, stamping, forming, etc.
When cutting some fiber materials, attention should be paid to the fiber direction to obtain the best mechanical strength. For example, the glass varnish should be cut at an angle of 45 degrees to the fiber, so that it is not easy to crack at the bottom when it is used for slot insulation. Insulation material processing places should pay attention to clean and dry.
The small and medium motor slot wedges are divided into two types: ordinary slot die and magnetic slot wedge. Ordinary tanks are made of bamboo or laminate. Bamboo wedges are treated with transformer oil and are generally used for Class E insulation; laminate wedges have higher electrical and mechanical strength than bamboo molds and can be used for Class B insulation. A U-shaped heat-resistant thick film (such as a polyester film with a thickness of 0.5 to 0.7 mm) is used as a small motor wedge to improve the space utilization of the groove and is suitable for mechanized fitting.
The length of the wedge should be 4-6 mm shorter than the slot insulation to prevent creepage during the withstand voltage test. The corners of both ends shall be removed and the surface shall be smooth and smooth to avoid damage to the insulation during insertion.
Magnetic wedges are typically used for open slots to improve electromagnetic performance. If the semi-closed groove or the semi-open groove core adopts a magnetic groove wedge, the size of the notch can be increased, and the winding can be easily embedded, which creates favorable conditions for mechanized weaving.
In the past, there were many types of magnetic wedges, and nowadays iron-fiber glass cloth laminates are generally used, and the relative magnetic permeability is 4-10, and the bending strength is not less than 150 MN/m2. The magnetic wedge must be tightly fitted with the slot. If loose, it will vibrate during operation and cause an accident.
Care should be taken to clean the core before weaving. If there is a bulge in the surface of the rotor and the groove, it must be repaired and flattened, and the iron debris will be blown off with compressed air. Cleaning should not be carried out in the inline area.
The insulation of the coil itself should be carefully inspected. If there is damage, it must be repaired with the same level of insulation material. If the shape of the forming coil is incorrect, it must be reshaped.
Before the weaving, workers must be familiar with the drawings, clearly understand the number of motor poles, winding pitch, lead direction, number of parallel branches, winding arrangement, end extension size, and other related technical requirements, so as to avoid errors in the assembly.
Reprinted from the network