Rotor production method

Patent metadata

Field	Value
Publication number	US-2017012509-A1
Application number	US-201615203492-A
Country	US
Kind code	A1
Filing date	Jul 6, 2016
Priority date	Jul 8, 2015
Publication date	Jan 12, 2017
Grant date	—

Abstract

A rotor production method includes: a first step of arranging a plurality of sintered bodies side by side with an insulating lubricant applied to an interface of at least one of the sintered bodies adjacent to each other, and then housing the sintered bodies in a cavity of a molding die such that the sintered bodies are arranged side by side in the cavity, the sintered bodies being precursors of a plurality of split magnets constituting one rare-earth magnet; a second step of turning the sintered bodies into the split magnets by performing hot working to impart magnetic anisotropy to the sintered bodies arranged in the cavity, and producing an integrated magnet in which the split magnets are integrated together with the lubricant interposed therebetween; and a third step of producing a rotor of a motor by inserting the integrated magnet into a magnet slot of the rotor.

First claim

What is claimed is:

1 . A rotor production method comprising:
arranging a plurality of sintered bodies side by side with an insulating lubricant applied to an interface of at least one of the sintered bodies adjacent to each other, and then housing the sintered bodies in a cavity of a molding die such that the sintered bodies are arranged side by side in the cavity, the sintered bodies being precursors of a plurality of split magnets constituting one rare-earth magnet; turning the sintered bodies into the split magnets by performing hot working to impart magnetic anisotropy to the sintered bodies arranged side by side in the cavity, and producing an integrated magnet in which the split magnets are integrated with each other with the lubricant interposed between the split magnets; and producing a rotor of a motor by inserting the integrated magnet into a magnet slot of the rotor.

2 . The rotor production method according to claim 1 , wherein the lubricant contains boron nitride.

3 . The rotor production method according to claim 1 , wherein a pre-forging coating thickness of the lubricant is equal to or more than 10 μm.

4 . The rotor production method according to claim 1 , wherein each of the sintered bodies has a Nd—Fe—B-based main phase with a nanocrystalline structure, and a grain boundary phase of a Nd—X alloy, where X is a metal element, the grain boundary phase being present around the main phase.

5 . The rotor production method according to claim 4 , wherein:
the Nd—X alloy constituting the grain boundary phase is any one of Nd—Co, Nd—Fe, Nd—Ga, Nd—Co—Fe, and Nd—Co—Fe—Ga, or is a mixture of at least two of Nd—Co, Nd—Fe, Nd—Ga, Nd—Co—Fe, and Nd—Co—Fe—Ga; and the Nd—X alloy is in a Nd rich state.

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamashita Osamu

Classifications

• Y10T29/49078

  Laminated · CPC title

• Y10T29/49076

  From comminuted material · CPC title

• H01F41/0273

  Imparting anisotropy (methods and devices for magnetising permanent magnets H01F13/003) · CPC title

• H01F41/0253

  for manufacturing permanent magnets · CPC title

• H01F1/0577

  sintered · CPC title