Winding is a very critical element in the process of motor production and processing. Whether it is the correctness of the motor winding data or the compliance of the insulation performance of the motor winding, it is a key indicator that must be highly valued in the manufacturing process.
Under normal circumstances, motor manufacturers will check the number of turns, normal resistance, and electrical insulation performance of the windings during the winding process and before dipping paint after wiring; then it is inspection tests and type tests to accurately determine whether the target motor meets the design requirements or not. Whether the technical performance of the trial prototype can meet the assessment standards. For new product motors that have not been produced, the following links are particularly important: in the electrical semi-finished product test link, check and judge the resistance compliance; in the inspection test link, in addition to the resistance compliance check, it can also be proved by no-load current Compliance of windings; for wound rotor motors, the test of rotor open circuit voltage or commonly known as transformation ratio inspection test can usually directly check and judge whether the winding data is normal, or whether the number of turns of the stator and rotor coils of the target motor is consistent with the design .
In fact, for any motor, its performance data has a certain correlation with power, voltage, number of poles, etc. Experienced testers will roughly evaluate the compliance of the motor in different test sessions.
According to the shape of coil winding and the way of embedded wiring, it can be divided into two types: centralized and distributed.
(1) Concentrated winding
Concentrated windings are used in salient pole stators, usually wound into rectangular coils, wrapped with yarn tape to shape, and then embedded in the iron core of convex magnetic poles after being soaked in paint and dried. Generally, the excitation coil of the commutator type motor and the main pole winding of the single-phase shaded pole type salient pole motor adopt centralized winding. Concentrated windings usually have one coil per pole, but there are also common pole forms, such as frame-type shaded pole motors, which use one coil to form two poles.
(2) Distributed winding
The stator of the motor with distributed winding has no convex pole palm. Each magnetic pole is composed of one or several coils embedded and wired according to certain rules to form a coil group. After electrification, magnetic poles of different polarities are formed, so it is also called hidden pole type. According to the different arrangements of embedded wiring, distributed windings can be divided into two types: concentric and stacked.
●Concentric winding consists of several coils with similar shapes but different sizes, which are embedded in the same central position to form a coil group in the shape of a word. Concentric windings can form biplane or triplane windings according to different wiring methods. Generally, the stator windings of single-phase motors and some three-phase asynchronous motors with small power or large-span coils adopt this type.
Laminated winding Laminated winding generally consists of coils of the same shape and size, one or two coil sides are embedded in each slot, and they are stacked and evenly distributed one by one at the outer end of the slot. There are two types of stacked windings: single stacked and double stacked. Only one coil side embedded in each slot is a single-layer stacked winding, or single-stacked winding; when two coil sides belonging to different coil groups are embedded in each slot, they are placed in the upper and lower layers of the slot, which is a double-layer stacked winding, or Called double stack winding. According to the change of the embedded wiring method, the stacked winding can be derived into cross type, concentric cross type, and single-layer and double-layer hybrid type. At present, the stator windings of three-phase asynchronous motors with large power generally use double-layer laminated windings; while small motors mostly use derivatives of single-layer laminated windings, but rarely use single-layer laminated windings.
Post time: Apr-03-2023