Classification of motor stator and rotor windings, and 7 stator winding methods
Magnetic pole division formed by stator winding
The stator winding forms the relationship between the actual number of magnetic poles according to the number of magnetic poles of the motor and the distribution of the windings, which can be divided into two types: dominant type and consequential pole type. In the dominant type winding, each group of coils forms a magnetic pole, and the number of coils in the winding is equal to the number of magnetic poles. In order to make the polarities N and S of the magnetic poles spaced apart from each other, the current directions in the two adjacent coils must be opposite, that is, the connection mode of the two adjacent coils must be connected to the tail end and the head end to the head end, that is, reverse series connection.
In the consequential-pole winding, each coil forms two magnetic poles, and the number of coils in the winding is half the number of magnetic poles, because the other half of the magnetic poles are formed by the magnetic lines of force that the coils generate. In the consequential-pole winding, the polarities of the magnetic poles formed by each coil are the same, so the current direction in all coils is the same, that is, the connection method of two adjacent coils should be tail-end to head-end, also known as serial connection.
Distinguish by the shape of the stator winding and the way of embedded wiring：
The stator winding can be divided into two types: centralized and distributed according to the shape of the coil winding and the way of embedded wiring.Concentrated windings generally consist of only one or several rectangular frame coils. After winding, it is wrapped and shaped with gauze tape, and then embedded in the iron core of the convex magnetic pole after being dipped in paint and dried. This winding is used in the excitation coil of DC motors, general-purpose motors, and the main pole windings of single-phase shaded-pole motors.
The stator of the motor with distributed winding has no salient pole palm, and each magnetic pole is composed of one or several coils embedded and wired according to a certain rule to form a coil group. According to the different forms of embedded wiring arrangements, distributed windings can be divided into two types: concentric and stacked. Concentric windings are several rectangular coils of different sizes in the same coil group, which are embedded one by one according to the same center position and arranged in a back-shaped type. Concentric windings are divided into single-layer and multi-layer. Generally, the stator windings of single-phase motors and some low-power three-phase asynchronous motors adopt this type.Laminated winding is a type in which all coils have the same shape and size (except for single and double coils), each slot is embedded with one coil side, and the outer ends of the slots are overlapped and evenly distributed one by one. Laminated windings are divided into single-layer stacked and double-layered windings.
The single-layer stacked winding, or single-stacked winding, is embedded with only one coil side in each slot; the double-layered winding, or double-layered winding, is embedded with two coil sides (divided into upper and lower layers) of different coil groups embedded in each slot. stacked windings. Due to the change of the embedded wiring method, the stacked winding can be divided into single and double-turn cross wiring arrangement and single and double-layer mixed wiring arrangement; In addition, the embedded shapes from the winding end are called chain windings and basket windings, which are actually stacked windings. Generally, the stator windings of three-phase asynchronous motors are mostly stacked windings.
Rotor winding
Rotor windings are basically divided into two types: squirrel cage type and wound type. The squirrel-cage structure is relatively simple, and its windings used to be inlaid copper bars, but most of them are cast aluminum at present. The special double squirrel-cage rotor has two sets of squirrel-cage bars.Wound-type rotor windings are the same as stator windings, and are also split-type and wave-type windings. The shape of the wave winding is similar to that of the stacked winding, but the wiring method is different. Its basic component is not the entire coil, but a single-turn unit coil, which needs to be welded into coil groups one by one after being embedded. Wave windings are generally used in the rotor windings of large AC motors or the armature windings of medium and large DC motors.
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