Stator and rotor in short: the fixed part of the motor is called stator, on which pairs of static main poles excited by DC are installed; The rotating part (rotor) is called armature core, and the armature winding is installed on it. After electrifying, induced electromotive force is generated, which plays the role of rotating magnetic field. And then generate electromagnetic torque for energy conversion. According to the shape and embedding mode of stator winding, stator winding can be divided into centralized and distributed according to the shape and embedding connection mode of coil winding. 1. Centralized winding Centralized winding is applied to salient-pole stator, which is usually wound into a rectangular coil, wound with warp tape, then dipped in paint and dried, and then embedded in salient-pole core. Generally, the excitation coil of commutator motor (including DC motor and ordinary motor) and the main pole winding of single-phase salient-pole motor adopt concentrated winding. Concentrated winding usually has one coil per pole, but it also has the form of common pole (hidden pole). For example, a frame-type shaded pole motor is a motor that uses one coil to form two magnetic poles. 2. The distributed winding motor stator has no salient pole palm, and each magnetic pole is composed of one or several coils embedded and wound according to certain rules to form a coil group, which forms magnetic poles with different polarities after being electrified, so it is also called hidden pole type. According to the different arrangement forms of embedded wiring, distributed windings can be divided into concentric and overlapping types. (1) Concentric winding Concentric winding is a zigzag coil group composed of several coils with similar shapes but different sizes embedded in the same central position. According to different connection modes, concentric windings can form biplane or tripolane windings. Generally, stator windings of single-phase motors and three-phase asynchronous motors adopt this type, and some have small power or large span coils. (2) Stacked winding Generally, stacked winding consists of coils with the same shape and size, and each slot is embedded with 1 or two coil sides, which are evenly distributed at the outer ends of the slots. Stacked windings are divided into single-layer and double-layer stacked windings. Only one coil side is embedded in each slot, which is a single laminated winding, or called a single laminated winding; When two coil sides belonging to different coil groups are embedded in each slot, they are placed on the upper and lower layers of the slot, which is a double-layer winding, or a double-layer winding. According to the change of embedded connection mode, stacked windings can be derived into cross, concentric cross and single-layer and double-layer hybrid. At present, the stator winding of high-power three-phase asynchronous motor generally adopts double laminations; However, small motors mostly use the derivative type of single laminated winding, and rarely use single laminated winding. Third, the rotor winding The rotor winding of AC asynchronous motor is divided into squirrel cage type and winding type. The structure of the squirrel cage is relatively simple. Generally, alloy aluminum is poured into the rotor core slot and is formed by short-circuiting two end rings. There are also copper bars embedded with welded copper end rings. In order to improve the starting performance, the squirrel cage can be made into special types such as deep ditch and double squirrel cage. The wound rotor winding is the same as the stator winding. In addition to the above various windings, wave windings can also be used. The wave winding is a single-turn or multi-turn rod-shaped unit coil. After embedding, the two components are welded at the ends to form an integral winding. Its wiring principle is different from the above winding, but its appearance is similar to that of double-layer winding. Waveform winding is often used in rotor winding of large AC motor and armature winding of DC motor. Different connection forms of stator windings can form different polarities, and motors can be divided into two types according to their polarity relations: explicit polarity type and ordinary polarity type. 1. salient pole winding A motor stator with four salient poles, each coil forms a magnetic pole; The polarities formed by two adjacent coils are different; Four poles are formed on four salient poles. Therefore, in salient pole winding, each coil group forms a magnetic pole, that is, the number of coil groups of the winding is equal to the number of magnetic poles. In addition, in order to make adjacent magnetic poles exist in pairs with N and S polarities, the current directions in two adjacent groups of coils must be opposite. Therefore, the connection mode of two adjacent coil groups must be reverse connection and series connection, which are called "head connection" and "tail connection" in electrician terminology. In fact, except for DC motors and single-phase salient-pole covered motors, there are no salient-pole pawls in general stators. This picture is a schematic diagram to illustrate the problem more vividly. 2. common pole winding figure 2-2 is a schematic diagram of the stator of common pole four-pole winding. As can be seen from the figure, two adjacent groups of coils have the same polarity, both of which are S-poles. Due to the principle of repulsion of the same polarity, the magnetic field formed by the coil returns through the adjacent salient poles, forming a closed magnetic circuit. So as to generate n magnetic poles with different polarities on salient poles without coils. Therefore, in ordinary magnetic pole winding, each coil group will form a pair of magnetic poles, and the number of coil groups in each phase winding is half of the number of magnetic poles. In common-pole winding, because the magnetic poles generated by each coil group have the same polarity, the current direction in all coils is the same, that is, two adjacent coil groups are connected in series, as shown in Figure (b). This connection is what electricians commonly call "end-to-end connection", that is, "end-to-end connection". Motor winding is a combination of one phase or all electromagnetic circuits composed of coil groups; The coil group consists of one or more coils connected in series. Therefore, the coil is the basic component of the motor winding, and it is also made of insulated wires (round or rectangular cross-section wires) wound in a certain shape. The coil can be one turn or hundreds of thousands of turns. The number of turns mainly depends on the power supply voltage and the parameters of the electromagnetic part of the motor, which is determined by calculation. There are many shapes of motor coils, but its basic structure consists of three parts: the straight part embedded in the iron core slot is called the effective edge, and a coil has two effective edges, which is the effective part of electromagnetic energy conversion; After the coil is embedded, the part connecting the two effective edges is located outside the slots at both ends of the iron core, which is called the coil end, which is an essential part of the coil structure, but it cannot be used for energy conversion. The lead wire is the beginning and end of the coil after winding, and it is also the connection point to lead out the coil current. The winding and embedding of centralized winding are relatively simple, but the efficiency is low and the running performance is poor. At present, most AC motor stators adopt distributed windings. According to different models, models and winding process conditions, the motor design has different winding types and specifications, so the technical parameters of its windings are also different.