Structural Characteristics and Classification of the Explosion Proof Motor

Explosion-proof motor is a kind of motor that can be used in flammable and explosive places, and it does not produce electric sparks during operation. Explosion-proof motors are mainly used in coal mines, oil and gas, petrochemical and chemical industries. In addition, it is also widely used in sectors such as textiles, metallurgy, urban gas, transportation, grain and oil processing, papermaking, and medicine. As the main electrical control devices, explosion-proof motors are usually used to drive pumps, fans, compressors and other transmission machinery.

Ⅰ. Classifications of the explosion proof motor

1. According to the principles of the explosion proof motor: explosion-proof asynchronous motors, VFD for synchronous motor and explosion-proof DC motors.

2. According to the place of use: explosion-proof motors used in coal mines and explosion-proof motors used in factories.

3. According to the principles of the explosion proof electric motor: explosion-proof motor, increased safety motor, positive pressure motor, non-sparking motor and dust explosion-proof motor, etc.

4. According to the equipment classification of explosion-proof motors: explosion-proof motors can be divided into explosion-proof motors for coal mine conveyors, explosion-proof motors for coal mine winches, explosion-proof motors for rock loaders, explosion-proof motors for local fans in coal mines, explosion-proof motors for valves, and fans Loud explosion-proof motors, marine explosion-proof motors, explosion-proof motors for cranes and metallurgy, and increased safety brushless excitation synchronous motors for supporting hydrogenation devices, etc. In addition, it can also be classified according to technical indicators such as rated voltage and efficiency, such as high-voltage explosion-proof motors, high-efficiency explosion-proof motors, high-slip explosion-proof motors, and high-starting torque explosion-proof motors.

Ⅱ. The structural characteristics of the explosion proof motor

Compared with an ordinary electric frequency converter, the structural features of explosion-proof motor mainly lie in the base, end cover, and junction box. The respective contact surfaces between the bottom and cover of the junction box are set as explosion-proof surfaces. There is no substantial difference between the explosion-proof surface and the mating surface of ordinary motors, but to achieve higher sealing requirements, the mating area is enlarged (such as a longer stop) and the mating accuracy is enhanced. Measures such as applying sealant and adding rubber gaskets are used in this part. In addition, its junction box must be tightly isolated from the inside of the casing, which is not available in ordinary motors. Once an "explosion" occurs inside the motor, the resulting pressure will explode the casing. In order to prevent this problem, the materials used in the base, end cover, junction box, etc. must be high in strength and large in thickness. And to carry out pressure test (generally a water pressure test) for these parts, they can be assembled and used only after they are qualified.