Broadly speaking, motors contain two parts: electrical and mechanical. The electrical part is the key to insulation. The mechanical part involves transmission theory and fluid mechanics. In addition, in the process of implementing energy conversion and transmission functions, various forms of loss are expressed in a heating manner, and natural heat transfer and heat exchange problems cannot be neglected. Therefore, it is not easy to make a good motor, and high-voltage motors are even more difficult.
Welding problems and avoidance measures
The connection between the windings of the motor windings, the connection between the winding lead and the leads, the lead wire and the connector is a frequent link in the welding problem. In the process of welding, welding and impermeable problems often lead to de-welding in the operation of the motor, resulting in increased resistance at the welding site, and severe local heating resulting in disconnection of the welding position.
Most of the problems occur in the winding motor rotor and headgear, stator rotor wire and the welding position of the wire, winding rotor motor star points and often a lot of wire head, but also a virtual welding or welding defects do not penetrate multiple points. To solve this kind of problem, we should make efforts to improve the process:
● Use highly reliable equipment and processes. For example, most motor manufacturers use relatively reliable methods such as mid-frequency welding, argon arc welding, and cold-pressing continuation tube assisted silver-copper solder filling.
Improvements in stator banding. After the connection, the binding and solidification of the welding position should be ensured, and the position of the solder joint should be suspended. The vibration of the motor during operation can prevent the solder joint from being forced to open.
● The use of a rotor bracket ensures that the ends of the winding rotor are supported to prevent radial force welding.
● Special attention should be paid to the connection between the lead wire and the wire, and the thin wire magnet wire should be avoided as much as possible. That is, the difference in length and width of the cross-section of the flat wire is avoided.
Groove shedding and preventive measures
In the process of manufacturing high-voltage motors, some motor manufacturers use immersion technology. If the stator core coil slot has a low full-rate, the curing effect of the windings cannot be ensured during dipping, and the coils are affected by the electromagnetic force in the core slots when the motor runs. The vibration causes the wedge to fall off due to vibration, thus causing problems such as brooms and heating of the windings.
At present, many domestic motor manufacturers use magnetic slot wedges, although the motor efficiency and performance improvement effect is obvious, but the slot wedge off the problem is more prominent. To solve this problem, you should control in the following areas:
● The matching relationship between the stator slot and the slot wedge is well controlled. The cooperation between the two slots should not be too loose.
● The groove filling rate should not be too low when inserting the wire. If this problem persists, the filling effect must be ensured by the necessary stuffing insulation material and improving the impregnation effect. Such as the use of vacuum dipping process, control of paint viscosity, secondary dip lacquer and other specific measures.