Magnets in Permanent Magnet Motor
The largest application area of rare earth permanent magnet is permanent magnet motor, commonly known as motor motor. In the broad sense, motors include electric motors that convert electric energy into mechanical energy and transform mechanical energy into electrical energy. The law of electromagnetic induction or the law of electromagnetic force is used as electrical equipment as basic principles. The air gap magnetic field is the prerequisite for the working principle of the motor. The air gap magnetic field is called an inductive motor by electromagnetic excitation, and the permanent magnet is called permanent magnet motor.
The air gap magnetic field in the permanent magnet motor is generated by permanent magnets. It does not require additional electrical energy, nor does it need to increase an additional winding. The application of magnetic motors, especially among various small and micro -motors, has a wide range of applications.
The figure below is a simple working principle model of a simple permanent magnetic DC motor. The two permanent magnets generate magnetic fields at the coil of the center. The component of the middle rotation is called a rotor, and the motionless part is called a stator. Obviously, the permanent magnet in the figure below belongs to the stator and the coil belongs to the rotor.
For the rotating motor, when the permanent magnet is a stator, the tile -shaped magnet with a large arc surface sticker is pasted in the case. , Or embed the rotor core in a square -shaped shape, as shown below.
For the linear motor, the permanent magnet is mainly square and peaceful, and the cylinder -shaped linear motor also uses axial magnetic ring magnetic steel.
The permanent magnet motor magnet has the following characteristics:
1. The shape will not be too complicated (except for some microcomputers, such as VCM motors), mostly rectangular, tiles, fan -shaped, and bread shapes. Especially under the premise of motor design reduction, many of them will use embedded square magnetic magnetic magnetic steel;
2. The magnetic charging is relatively simple. Basically, it is a single -pole massage. After the assembly is assembled, a multi -polar magnetic circuit is formed. If the whole ring is made, such as bonding the iron boron magnetic ring or the thermal pressure magnetic ring, it is generally used for multi -pole radiation and magnetic;
3. The core of the technical requirements is that the high temperature stability, the consistency of the magnetic flux and the adaptability. The requirements for salt fog will be stricter. Driving motor magnetic steel will require high temperature stability very well;
4. Magnetic energy accumulates high, medium and low -end, but most of the stubborn power is the medium and high -end level. At present, the driving motor magnetic steel plate of electric vehicles is mostly high magnetic energy accumulation, high correction stubborn power, such as 45UH, 48UH, 50UH, 42EH, 42EH, 42EH, 42EH , 45EH, etc., mature diffusion technology is essential;
5. Segmental bonding magnetic steel has been widely used in the field of high -temperature motors. The purpose is to increase the segmented insulation of magnetic steel to reduce the vortex loss of magnetic steel during the running of the motor. Some magnetic steel will be on the surface Increase epoxy coating to increase its insulation.
Key detection items of motor magnet:
1. High temperature stability. Some customers will require the opening of the road magnetic decay, and some customers will require the semi -open road magnetic decay. In addition to the high temperature, the magnetic steel is also affected by the reverse magnetic field. It must be tested and monitored;
2. Magnetic flux consistency. Magnet is the source of magnetic fields of motor rotor or stator. If there is consistency differences, the motor vibration and power will be reduced and the power will affect the function of the overall motor. Within, some require 3%or even 2%. For factors that affect the consistency of magnetic flux, they must be considered, such as the consistency of the remaining magnetic tolerance, the consistency of the tolerance, and the consistency of the inverted coating.
3. Adaptability. The magnetic steel of the table stickers is mostly tile shape. For the two -dimensional test method of the angle and curved routine, the error error is large or difficult to test. At this time, it is necessary to consider its adaptability. Controlling the gaps of accumulated addition, some magnetic steel of the tailor tail grooves need to be considers the tightness of the assembly. It is best to use the user’s assembly method to self -control the imitation tool to test the adaptability of the magnetic steel.
Purchasing personnel need to focus on the following points:
1. Rare earth market. As the largest proportion of single costs in motors, magnetic steel has always been the main source of motor cost compression. Because the shape of the motor magnetic steel is relatively simple, the most proportion is the cost of material. Purchasing personnel need to pay attention to rare earth metals at any time. Market conditions to understand the price trend of motor magnetic steel;
2. Performance indicators. The shape of magnetic steel is relatively simple, and the proportion of material costs is very large, so the high and low performance indicators will directly affect the weight of the heavy rare earth in magnetic steel, which directly affects the cost of magnetic steel;
3. Quantity. Most of the motor magnetic steel is relatively large, with a small length of 10mm and a large as soon as 100 mm. The number of rough films will not be much. The problem of sharing mold fees causes high costs.