Motor and rotor

Abstract

A motor including a stator and a rotor. The stator includes teeth and windings. Each tooth has a distal portion defined by a radially inward side of the stator. The rotor, which is arranged inward in the radial direction from the stator, includes a rotor core, magnets, and salient poles. Each salient pole is separated by a void from the magnet that is adjacent in the circumferential direction. The distal portion of each tooth is longer than a radially outward side of each magnet.

1 . A motor comprising:
 a stator including a plurality of teeth, which extend inward in a radial direction and are arranged along a circumferential direction, and a plurality of windings, which are wound around the teeth, wherein each tooth includes a distal portion located at a radially inward side of the tooth; and   a rotor arranged inward in the radial direction from the stator, wherein the rotor includes a rotor core, a plurality of magnets, which are arranged along a circumferential direction of the rotor core and function as first magnetic poles, and a plurality of salient poles, which are arranged on the rotor core and function as second magnetic poles, and each of the salient poles is separated by a void from an adjacent one of the magnets in the circumferential direction;   wherein the distal portion of the tooth is set to be longer in an axial direction than a magnet pole portion, which is formed at a radially outward side of the rotor in correspondence with each of the magnets.   
     
     
         2 . The motor according to  claim 1 , wherein when the distal portion is projected from the magnet pole portion in the axial direction by a projecting amount A, and the stator and the rotor are separated from each other in the radial direction by distance B, a ratio A/B is set to satisfy
   0<( A/B )≦1.5.
   
     
     
         3 . The motor according to  claim 1 , wherein when the distal portion is projected from the magnet pole portion in the axial direction by a projecting amount A, and the stator and the rotor are separated from each other in the radial direction by distance B, a ratio A/B is set to satisfy
   1.5≦( A/B )≦2.5.
   
     
     
         4 . A rotor comprising:
 a rotor core;   a plurality of magnets arranged along a circumferential direction of the rotor core and functioning as first magnetic poles; and   a plurality of salient poles arranged on the rotor core and functioning as second magnetic poles, wherein each of the salient poles is separated by a void from an adjacent one of the magnets in the circumferential direction;   wherein the salient poles are set to be longer in an axial direction than a magnet pole portion, which is formed at a radially outward side of the rotor in correspondence with each of the magnets.   
     
     
         5 . A motor comprising:
 the rotor according to  claim 4 ; and   a stator arranged outward in a radial direction from the rotor, wherein the stator includes a plurality of teeth, which extend inward in the radial direction toward the rotor and are arranged along a circumferential direction, and a plurality of windings, which are wound around the teeth;   wherein the salient poles are projected in the axial direction from the magnetic pole portions by a projecting amount C, and the stator and the rotor are separated from each other in the radial direction by distance B, a ratio C/B is set to satisfy
   0<( C/B )<2. 
   
     
     
         6 . A rotor comprising:
 a rotor core;   a plurality of magnets arranged along a circumferential direction of the rotor core and functioning as first magnetic poles; and   a plurality of salient poles arranged on the rotor core and functioning as second magnetic poles, wherein each of the salient poles is separated by a void from an adjacent one of the magnets in the circumferential direction;   wherein the salient poles are each formed by a salient pole member formed discretely from the rotor core and fixed to the rotor core.   
     
     
         7 . A rotor comprising:
 a rotor core including a plurality of magnet seats arranged along a circumferential surface of the rotor core in a circumferential direction;   a plurality of magnets functioning as first magnetic poles and arranged on corresponding ones of the magnet seats; and   a plurality of salient poles functioning as second magnetic poles, wherein each of the salient poles is separated by a void from an adjacent one of the magnets in the circumferential direction, wherein
 the rotor core includes a first core member and a second core member, which is arranged on the same plane as the first core member and is magnetically separated from the first core member, 
 the first core member includes a plurality of first blocks, each including a first seat portion and a first salient pole portion, wherein the first seat portion is located at a preceding side, in a first circumferential direction, of one of the magnet seats, and the first salient pole portion is located at a succeeding side, in the first circumferential direction, of one of the salient poles adjacent to the first seat portion in the first circumferential direction; and 
 the second core member includes a plurality of second blocks, each including a second seat portion and a second salient pole portion, wherein the second seat portion is located at a succeeding side, in the first circumferential direction, of one of the magnet seats, and the second salient pole portion is located at a preceding side, in the first circumferential direction, of one of the salient poles adjacent to the second seat portion in a direction opposite to the first circumferential direction.