Rotor of motor which uses magnets

Abstract

A rotor ( 10 ) of a motor includes a rotor core ( 11 ) and a plurality of magnets ( 14 a, 14 b ) which are arranged at a circumferential surface of the rotor core or at the inside of the rotor core, the length of a magnet of the plurality of magnets in the axial direction of the rotor core determined in accordance with the residual magnetic flux density of the magnet. The axial direction length of the magnet is preferably determined by multiplying a reference axial direction length of the magnet with the residual magnetic flux density of the magnet and dividing this by a reference residual magnetic flux density of the magnet.

1 . A rotor of a motor comprising
 a rotor core and   a plurality of magnets which are arranged at a circumferential surface of said rotor core or at the inside of said rotor core,   wherein the length of a magnet of said plurality of magnets in the axial direction of said rotor core is determined in accordance with the residual magnetic flux density of said magnet.   
     
     
         2 . The rotor of a motor as set forth in  claim 1 , wherein the axial direction length of said magnet is determined by multiplying a reference axial direction length of said magnet with the residual magnetic flux density of said magnet and dividing this by a reference residual magnetic flux density of said magnet. 
     
     
         3 . The rotor of a motor as set forth in  claim 1 , wherein the axial direction length of said magnet is made shorter than the axial direction length of said rotor core. 
     
     
         4 . The rotor of a motor as set forth in  claim 1 , wherein
 the inside of said rotor core is formed with a plurality of magnet holding holes which hold said plurality of magnets in the axial direction,   said plurality of magnets are held in said plurality of magnet holding holes,   the resin which is filled in the gaps between said plurality of magnets and said magnet holding holes is used to fix said magnets in place, and   the amounts filled of said resin differ according to the axial direction lengths of said plurality of magnets.   
     
     
         5 . The rotor of a motor as set forth in  claim 4 , wherein
 one ends of said plurality of magnets are positioned at one ends of said magnet holding holes in the axial direction of said rotor core, and   said resin is filled between the other ends of said plurality of magnets and the other ends of said magnet holding holes.   
     
     
         6 . A method of production of a rotor as set forth in  claim 1  comprising steps of
 arranging said plurality of magnets in a plurality of magnet holding holes which are formed in an axial direction inside said rotor core, 
 filling a resin in the gaps between said magnet holding holes and said magnets to fix said magnets in place, and 
 making the amounts of said resin filled different in accordance with the axial direction lengths of said magnets. 
 
     
     
         7 . The method of production of a rotor as set forth in  claim 6  further comprising steps of
 positioning one ends of said plurality of magnets at one ends of said magnet holding holes in the axial direction of said rotor core and 
 making said resin be filled between the other ends of said plurality of magnets and the other ends of said magnet holding holes.