Claims
- 1. A method of producing a permanent magnet rotor, comprising the steps of:
- laminating a plurality of steel sheets to form a rotor yoke having 2n times (n is a positive integer) of magnetic poles on an outer periphery thereof, and a plurality of slots for receiving field permanent magnets at bases of all or every other magnetic poles at substantially equal distances from a rotatable shaft hole;
- making said field permanent magnets from a rare earth material;
- forming said field permanent magnets to a predetermined thickness;
- electrically nickel plating said field permanent magnets such that said nickel plating provides a plated layer having a thickness between 5 .mu.m and 20 .mu.m at a center of said field permanent magnets and has a substantially uniform thickness at said center and ends of said field permanent magnets without any electrode mark;
- disposing said plated field permanent magnets in said slots;
- heating said rotor yoke at a temperature above a curie point of said permanent magnets but below a temperature for retaining performance of said rare earth material;
- shrinkage fitting said heated rotor yoke to a rotatable shaft; and
- making magnetization of said rotor yoke.
- 2. A method of producing a permanent magnet rotor, comprising the steps of:
- laminating a plurality of steel sheets to form a rotor yoke having 2n times (n is a positive integer) of magnetic poles on an outer periphery thereof, and a plurality of slots for receiving field permanent magnets at bases of all or every other magnetic poles at substantially equal distances from a rotatable shaft hole;
- making said field permanent magnets from a rare earth material;
- forming said field permanent magnets to a predetermined thickness;
- treating electroless nickel plating of said field permanent magnets at a temperature between 350.degree. C. and 400.degree. C.;
- disposing said plated field permanent magnets in said slots;
- heating said rotor yoke at a substantially same temperature as that of thermal treatment of said electroless nickel plating; and
- shrinkage fitting said heated rotor yoke to a rotatable shaft while doing said thermal treatment of said nickel plating.
Parent Case Info
This application is a division of application Ser. No. 08/590,466, filed Jan. 23, 1996, now abandoned.
US Referenced Citations (22)
Divisions (1)
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Number |
Date |
Country |
Parent |
590466 |
Jan 1996 |
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