Why are shaded pole motors widely used in household appliances?
Shaded pole motor, also known as shaded pole motor, is one of single-phase AC motors. Cage type inclined slot cast aluminum rotor is usually used. According to the different shape and structure of stator, it is divided into salient pole covered pole motor and hidden pole covered pole motor.
The salient feature of shaded pole motor is that the structure is very simple, there is no centrifugal switch, the power loss of shaded pole motor is very large, the motor power factor is low, and the starting torque is also very low. They are designed to remain small and have low power ratings. The speed of the motor is as accurate as the power frequency applied to the motor, which is often used to drive clocks and watches. The shaded pole motor rotates only in one specific direction, the motor cannot rotate in the opposite direction, the loss caused by the shaded pole coil, the motor efficiency is low, and its structure is simple. These motors are widely used in household fans and other small capacity appliances.Working principle of shaded pole motor
The shaded pole motor is an AC single-phase induction motor. The auxiliary winding is composed of a copper ring, which is called the shaded pole coil. The current in the coil delays the phase of the magnetic flux at the magnetic pole, so as to provide a rotating magnetic field. The rotation direction is from the non shaded pole to the shaded pole ring.
In a shaded pole motor, the rotor is placed in a simple C-core, and half of each magnetic pole is covered by a shaded pole coil. When AC current passes through the power supply coil, pulsating magnetic flux will be generated. When the magnetic flux passing through the shading coil changes, voltage and current will be induced in the mask coil, which corresponds to the change of magnetic flux from the power coil. Therefore, the magnetic flux under the cover coil lags behind that of the rest of the coil. The rotor rotates by generating a small rotation in the magnetic flux. The following figure shows the magnetic flux line obtained by finite element analysis.Working characteristics of shaded pole motor
1. Reasonable structural design, flexible outgoing line direction, and the junction box of shaded pole motor can be installed rotatably
2. Superior shaded pole motor performance, low noise, low vibration, high performance protection grade
3. There are many choices to meet the needs of various users and install thermistors
4. The optimized design has high efficiency and can produce considerable energy-saving effect
5. The installation of dust-proof sealing ring, heating belt, oil-proof sealing ring, oil injection, special shaft extension, special flange and other requirements.