Composite type permanent magnet for synchronous permanent magnet motor rotor

Abstract

The invention discloses a composite type permanent magnet for a synchronous permanent magnet motor rotor, comprising permanent magnets, a permanent magnet support and a permanent magnet sheath, the two permanent magnets are symmetrically fixedly connected on the outer wall of the permanent magnet support, the permanent magnets and the permanent magnet support form a cylindrical composite permanentmagnet unit with a smooth outer wall surface, the permanent magnet sheath is sheathed on the composite permanent magnet unit, and the permanent magnet sheath and the composite permanent magnet unit are in interference fit; and the permanent magnet support is made from low-carbon steel. The composite type permanent magnet disclosed by the invention reduces consumption of permanent magnet materials, greatly reduces cost and can directly replace the original cylindrical permanent magnet part, thus a production line does not need to be changed; and high-strength alloy steel can be replaced by adopting austenitic stainless steel, thus material cost of the permanent magnet sheath is reduced.

Description

Technical field: [0001] The invention relates to a composite permanent magnet for a synchronous permanent magnet motor rotor. Background technique: [0002] Due to the high speed of the magnetic levitation motor, the volume is much smaller than that of the ordinary motor. Therefore, some medium-power magnetic levitation permanent magnet motors have adopted monolithic permanent magnets that are simple to manufacture. There are two advantages of doing this: first, the rotor has a simple structure and is easy to manufacture; second, the rotor mandrel can be made of non-magnetic materials, so as to prevent the magnetism of the rotor permanent magnet from interfering with the work of the magnetic bearing. [0003] But the disadvantages of integral permanent magnets are also obvious: [0004] 1) The amount of permanent magnet material is large, the cost is high and resources are wasted. [0005] 2) The stress of the permanent magnet sheath is very large, and expensive high-stre...

AI Technical Summary

Problems solved by technology

[0004] 1) The amount of permanent magnet material is large, the cost is high and resources are wasted

[0005] 2) The stress of the permanent magnet sheath is very high, so expensive high-strength alloy materials must be used

[0007] In order to keep the interference connection between the permanent magnet and the sheath reliable and to offset the loosening caused by the thermal expansion gap, the stress of the sheath is very large (in some cases it can reach 700-1000MPa), so that expensive high-strength alloy materials must be used

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