Main properties of permanent magnetic material _ ndfeb strong magnet manufacturers
Main properties of permanent magnetic material & ensp;
1, remanence intensity & ensp;
After saturated magnetization to the permanent magnet material in the outer magnetic field, when the external magnetic field is zero, the permanent magnet material of magnetic induction intensity values.
The gas gap flux density index data directly related to the motor.
Magnetic induction intensity value is higher, the air gap flux density of the motor will be higher, such as motor torque constant, back emf coefficient of the main indicators to achieve best value, motor of electric load and load value relationship can be the most reasonable, can achieve the best efficiency.
2, the coercive force Hc (
Magnetic induction coercive force & ensp;
Permanent magnetic material under the condition of the saturation magnetization, when & ensp remanence intensity;
Reverse magnetic field strength drops to zero need.
The index and motor ability of resistance to demagnetization namely overload ratio and air gap flux density and other related indicators.
The value, the greater the resistance to demagnetization of the motor ability stronger, the larger the overload, the strong demagnetization dynamic working environment and the stronger ability to adapt.
At the same time, motor air gap flux density will be increased.
3, the maximum magnetic energy product: BHmax
Permanent magnet magnetic circuit provides the maximum magnetic energy outward.
The index is directly related to the amount of permanent magnet in the motor, BHmax
, the greater the herald of the permanent magnet material of external magnetic circuit can provide magnetic energy, the greater the power is in the same circumstances motor used in the permanent magnetic material is less.
4, the intrinsic coercive force: Hc
The index is when remanent magnetization & ensp;
Magnetic field intensity values drop to zero.
Demagnetization curve & ensp;
B = 0
When the corresponding & ensp;
Value only that permanent magnets can not provide to the outer magnetic circuit energy at this time, does not represent permanent magnet itself does not have the energy.
But when & ensp;
M = 0
When the corresponding & ensp;
Value says it now has permanent magnet demagnetization, real itself has been completely without magnetic energy storage.
Although & ensp;
Is directly related to machine working point, but it is the real coercive force of permanent magnet, representing the permanent magnet with magnetic energy and resistance to the ability of the magnetic field.
The size of the intrinsic coercive force is closely related to the temperature stability of the permanent magnetic material.
The higher the intrinsic coercive force, the higher the working temperature of permanent magnetic material might.
5, temperature coefficient, & alpha;
Temperature is one of the main factors of influence on to the magnetism of permanent magnet material, when the temperature of each change & ensp;
1 ℃ when magnetic reversible change percentage is called the temperature coefficient of magnetic materials.
Temperature coefficient can be divided into the remanence temperature coefficient and temperature coefficient of coercive force.
The index had a greater influence on the stability of the performance of the motor, the higher the temperature coefficient, when the motor running from cold to hot index changes, the greater the it directly limits the use of the motor temperature range.
Indirectly affect the power of the motor volume.