Shaded pole motors, also known as cover motors, cover motors or wind turbine drive motors, are named for their structural features. The design and manufacture of shaded pole motors have high technical content and complexity, and have been widely used in electronic information, precision instruments, medical equipment and other fields.
The structural characteristics of the shaded pole motor are: the rotor and the stator are made of magnetic materials and conductive materials respectively. The central part of the rotor is a circular permanent magnet, and there are many U-shaped magnetic steels around the outer circumference of the rotor. The stator consists of several curved conductive coils, which wrap around the outside of the rotor, and the way the coils are connected is very complicated. The cover buckle of the shaded pole motor is cast as a whole. After being put into the rotating column, the cover buckle rotates after being energized, reducing the physical space between the cover buckle and the U-shaped magnetic steel, thereby achieving the rotation of the rotor.
During the working process of the shaded pole motor, the magnetic poles of the rotor are changing alternately, resulting in the generation of AC electromotive force in the conductive coil in the stator, and at the same time, the counter electromotive force generated by the rotation of the rotor. Under the action of these two electromotive forces, the The conductive coil forms a magnetic field, thus realizing the drive of the shaded pole motor. The speed of the shaded pole motor is determined by the voltage of the DC power supply and the number of magnetic poles of the stator.
Shaded pole motors have many advantages, such as:
1. The structure is simple and can be assembled quickly.
2. Large and stable torque.
3. Low noise, long life and stable performance.
4. The friction loss of self-made bearings is small, so the efficiency is high and electric energy can be saved.
5. The control circuit is simple and cost-effective.
Due to the special structure of the shaded pole motor, there are many fields of application of this motor. For example, wind power generation systems, lamps, automated machining equipment, industrial automation equipment, textile machinery, vending machines, various medical equipment, robots, electric toys and control systems, etc.
At the same time, the shortcomings of shaded pole motors cannot be ignored. For example, due to the existence of the magnetic field, the shaded pole motor itself is relatively heavy, and it is difficult to pass the electric vehicle test standard. The matching ability of the shaded pole motor is not too strong, depending on the type of motor, the commonly used standard specifications are quite different, and they cannot be interchanged well. In addition, compared to many other DC motors, shaded pole motors have a high DC internal resistance, tend to heat up at low voltages, and are not very efficient.
