[Knowledge Sharing] Why do DC permanent magnet motor poles mostly use rectangular magnets?

The permanent magnet auxiliary exciter is a new type of external rotor DC permanent magnet motor. Its rotating choke ring is directly suspended deep in the shaft. There are 20 magnetic poles on the ring. Each pole has an integral pole shoe. The pole body is composed of three rectangular pieces. It is composed of magnetic steel and is bonded into a whole with “914″ glue. The pole body is wrapped and solidified with latitude-free glass ribbons to form a protective sleeve. Each pole body and pole shoe are made of two pieces of stainless steel.

In a DC permanent magnet motor, when other parameters remain unchanged, the higher the residual magnetism of the magnet, the smaller the current, and the lower the speed. This is correct. From this, you can analyze by yourself which magnet of your two prototypes is better. The residual magnetism is large. As for the principle, when other parameters remain unchanged, the higher the residual magnetism of the magnet, the greater the magnetic flux of each pole of the motor. According to the speed formula of the DC motor n=(U-IR)/CeΦ≈U/CeΦ, it can be very It is easy to conclude that the larger Φ, the lower the speed. The lower the speed, the smaller the no-load loss, and the smaller the no-load current.

The locked-rotor torque of the DC permanent magnet motor is related to the thickness of the magnet and the strength of the magnetic field. If the thickness can change the strength of the magnetic field, it will be relevant. During the assembly process of the magnet of the embedded permanent magnet motor, if it is manually Applying glue to the surface of the magnet makes it inconvenient for the operator to grasp the magnet. At the same time, due to imperfections in the existing technology when inserting the magnet into the slot, friction with the slot wall will inevitably occur. Further, The glue on the surface of the magnetic steel that is manually applied and has a small glue coverage area is unevenly distributed, resulting in poor adhesion, and the magnetic steel may fall off during later use.