Plastic-sealed motor consists of plastic-sealed stator, shaft, rotor, bearing, end cover, thermal protector, lead-out wire and socket. The stator core of plastic-encapsulated motor is assembled into a whole circle by two semicircular cores. Semi-circular iron core is made of high-quality cold-rolled silicon steel sheet with carbide progressive die on high-speed punching machine, and then pressed into semi-circular iron core with FASTEC or VICS self-locking iron core. After the semi-circular iron core is made, two semi-circular insulating sheaths are respectively sleeved at both ends of the semi-circular iron core, and then the semi-circular iron core is wound and spliced, so that plastic packaging can be realized. During plastic packaging, the stator core and lead embedded with the coil are first put into the injection-molded metal mold, and then injection-molded.

There are three ways to assemble the semi-circular core structure:

(1) The welding structure adopted by Toshiba Company in Japan, after two semicircular iron cores are wound, argon arc welding is adopted to make the two semicircular iron cores form a whole circle. Pay attention to the special fixture to ensure that the winding is not damaged, so as to avoid inter-turn short circuit or breakdown.

② The semi-iron core fastening structure adopted by Matsushita Corporation of Japan is injection molded after fastening, so that the two semicircles become a whole. But be careful not to put it in the wrong place, and plastic can't enter the joint surface.

(3) Japanese Kusatsu motor adopts press-fit structure, that is, there are corresponding convex and concave parts on the joint surface, and the two parts are pressed together to make them closely fit. It is required that the punching precision is high and the core lamination precision is high.

The stator winding of plastic-encapsulated motor is annular spiral tube type. The enameled wire is directly wound on the semi-circular stator core at high speed by using the microcomputer-controlled annular spiral motor stator winding machine and special fixture. Because the winding speed is as high as 2500 rpm, the quality of enameled wire is required to be stable, and the plasticity, strength and paint film firmness of the wire shall not be damaged under the action of winding tension. The arrangement of wires should be tight and uniform to avoid turn-to-turn short circuit or grounding breakdown; When the winding is spliced into a whole circle, the wiring between each coil and the main and secondary windings should be correct; The joints between wires should be covered with insulating paint tubes and firmly tied to prevent them from being pulled off.

Plastic-sealed motor adopts new thermosetting plastic, which requires excellent performance, good molding process, fast curing speed and easy demoulding. Thermosetting plastics are cured in hot state and will not be deformed or damaged when used at high temperature. There are mainly unsaturated polyester resin type and epoxy resin type. When used, stabilizers, lubricants, release agents, dyes, curing and curing accelerators, anti-aging agents, antistatic agents, flame retardants, etc. Also added.

Compared with the common motor, the plastic-encapsulated motor has the following advantages: ① Beautiful appearance, small size and light weight, and the length and weight of the machine body are reduced by about 25% compared with the metal shell motor. And is suitable for large-scale automatic production. ② Low noise. Due to the symmetrical concentric packaging of the stator core and the plastic structure, the stiffness of the stator is improved and the noise is reduced. Under the power frequency power supply, the sound pressure intensity of plastic sealed motor is 7 decibels lower than that of hard shell motor; Under the frequency conversion power supply, it is reduced by 9 decibels. ③ Low vibration. Because the stator of the motor has become a whole, the unbalance of the rotor is small, which inhibits the vibration. ④ The motor has good insulation performance. For example, after immersion test, the insulation performance of the injection-molded stator and the paint-dipped stator of the plastic-encapsulated motor of Mitsubishi Corporation of Japan kept at10 ~10Ω, while the latter immediately dropped below10Ω. Comparing the corona discharge characteristics of the two, the corona onset voltage (CSV) after injection molding insulation is 65,438 0.3 times higher than that before immersion painting insulation, and 65,438 0.3 times higher than that after immersion painting insulation. In addition, the plastic encapsulated motor also has the characteristics of corrosion resistance, moisture resistance and high temperature resistance. Compared with ordinary motors, this motor can save electricity by about 10%. A series of advantages of plastic encapsulated motor make it widely used in household appliances.