The world's first prototype motor is a permanent magnet […]
The world's first prototype motor is a permanent magnet motor, but was poor performance permanent magnet materials, which occupied the mainstream electromagnetic motor. The advent of aluminum-nickel-cobalt permanent magnet of the permanent magnet motor began to develop, but because of its relatively high price, so the aluminum-nickel-cobalt permanent magnet motor application surface is not widely used. Since the advent of inexpensive ferrite before the application of a substantial increase in the amount of permanent magnet motor, the motor application surface from toys, audio-visual motors, micro-motor car and drive to a low-power servo drives for industrial use and so on.
According to statistics, the following 500W DC permanent magnet motor in accounting for more than 92%, most of ferrite permanent magnet motor. Ferrite is still in use, but because of its magnetic properties became poor, not suitable for high-performance motor is required, and thus the 1960s there have been rare earth samarium cobalt permanent magnet, which is more than four times the maximum energy product of aluminum-nickel-cobalt, ferrite is more than five times body.
Appear to make samarium cobalt permanent magnets of high performance servo motors achieved,
However, due to the high price of samarium cobalt permanent magnets, which limits its application. 1980s appears NdFeB permanent magnet materials, in addition to operating temperature and magnetic temperature coefficient of less than samarium cobalt permanent magnet in vitro, other properties are more than samarium cobalt and neodymium iron boron permanent magnets is much lower than samarium cobalt price. Appearance and performance of high-performance permanent magnet continues to improve, it will cause a huge change in the motor industry. Various servo motors expected, both DC and AC, or stepper motor will eventually transition to the permanent magnet motor, and even a wide field of application of AC induction motor eventually to be replaced by various types of permanent magnet motor.