SHENZHEN DONGMING MOTOR CO., LTD.
As it is indicated in name of permanent magnet DC motor, the field poles of this motor are essentially made of permanent magnet. A PMDC motor mainly consists of two parts. A stator and an armature. Here the stator which is a steel cylinder. The magnets are mounted in the inner periphery of this cylinder. The permanent magnets are mounted in such a way that the N – pole and S – pole of each magnet are alternatively faced towards armature as shown in the figure below. That means, if N – pole of one magnet is faced towards armature then S – pole of very next magnet is faced towards armature.
In addition to holding the magnet on its inner periphery, the steel cylindrical stator also serves as low reluctance return path for the magnetic flux. Although field coil is not required in permanent magnet DC motor but still it is sometimes found that they are used along with permanent magnet. This is because if permanent magnets lose their strength, these lost magnetic strengths can be compensated by field excitation through these field coils. Generally, rare earth hard magnetic materials are used for these permanent magnet.
Except for flat dc motor, mostly dc motors are with round shape as following:
This kind of design is more elegant. Sometimes brushed dc motor need to work together with gearbox, in this situation, the round design are more suitable.
Common round dc motor including 310 round dc motor, 370 round dc motor, 380 round dc motor, 385 round dc motor, 395 round dc motor, 520 round dc motor, 528 round dc motor and 3525,3530,3540 series round dc motor. Larger ones we have 545 round dc motor, 555 round dc motor and 775 round dc motor.
Also we have another type dc motor with round design, they are brushless dc motor we will referred in another part.