Rotor and Motor

Abstract

A motor includes a rotor and a stator. The rotor includes a plurality of magnets, which function as first magnetic poles, and salient poles, which function as second magnetic poles. A ratio X 1 :X 2 of a quantity X 1 of magnetic pole portions of the rotor, which is the sum of the quantity of the magnets and the quantity of the salient poles, and the quantity X 2 of slots is 2n:3n (n being a natural number). The sum of a magnetic pole occupying angle θ 1 of the magnet and a magnetic pole occupying angle θ 2 of the salient pole is 360°. The magnetic pole occupying angle θ 1 is set in a range of 180°<θ 1 ≦230°.

1 . A motor comprising:
 a rotor including a rotor core, a plurality of magnets arranged along a circumferential direction of the rotor core to function as first magnetic poles, and salient poles formed integrally with the rotor core and arranged between adjacent ones of the magnets in the circumferential direction to function as second magnetic poles; and   a stator arranged facing toward the rotor and including a plurality of slots;   wherein the magnets and salient poles each have a quantity in which the quantities sum together to a quantity x 1  of magnetic pole portions of the rotor, and the slots are in a quantity x 2 , in which a ratio x 1 :x 2  of the quantity of the magnetic pole portions to the quantity of the slots is 2n:3n (n being a natural number);   when an electrical angle corresponding to an angular range from an initiating point, which is set between each magnet and the salient pole that is adjacent to one side of the magnet in the circumferential direction, to a terminating point, which is set between the magnet and the salient pole that is adjacent to the other side of the magnet in the circumferential direction, is defined as a magnetic pole occupying angle θ 1  of each of the magnets, and an electrical angle corresponding to an angular range between the initiating point and the terminating point on two sides of each salient pole in the circumferential direction is defined as a magnetic pole occupying angle θ 2  of each of the salient poles, in which the magnetic pole occupying angle θ 1  and the magnetic pole occupying angle θ 2  sum to 360°; and   the magnetic pole occupying angle θ 1  is set in a range of 180°<θ 1 ≦230°.   
     
     
         2 . The motor according to  claim 1 , wherein the magnetic pole occupying angle θ 1  is set in a range of 200°≦θ 1 ≦220°. 
     
     
         3 . The motor according to  claim 2 , wherein the magnetic pole occupying angle θ 1  is set in a range of 208°≦θ 1 ≦216°. 
     
     
         4 . The motor according to  claim 1 , wherein a clearance is formed between the magnet and the salient pole that are adjacent to each other in the circumferential direction of the rotor; and
 the initiating point and the terminating point of each of the magnetic pole occupying angles θ 1  and θ 2  is a median point in the circumferential direction of the clearance.   
     
     
         5 . A motor comprising:
 a rotor including a rotor core, a plurality of magnets arranged along a circumferential direction of the rotor core to function as first magnetic poles, and salient poles formed integrally with the rotor core and arranged between adjacent ones of the magnets in the circumferential direction to function as second magnetic poles; and   a stator arranged facing toward the rotor and including a plurality of slots;   wherein the magnets and salient poles each have a quantity in which the quantities sum together to a quantity x 1  of magnetic pole portions of the rotor, and the slots are in a quantity x 2 , in which a ratio x 1 :x 2  of the quantity of the magnetic pole portions to the quantity of the slots is 3n−1:3n (n being an odd number that is greater than or equal to 3) or 3n−2:3n (n being an even number that is greater than or equal to 4);   when an electrical angle corresponding to an angular range from an initiating point, which is set between each magnet and the salient pole that is adjacent to one side of the magnet in the circumferential direction, to a terminating point, which is set between the magnet and the salient pole that is adjacent to the other side of the magnet in the circumferential direction, is defined as a magnetic pole occupying angle θ 1  of each of the magnets, and an electrical angle corresponding to an angular range between the initiating point and the terminating point on two sides of each salient pole in the circumferential direction is defined as a magnetic pole occupying angle θ 2  of each of the salient poles, a sum of the magnetic pole occupying angle θ 1  and the magnetic pole occupying angle θ 2  is 360°; and   the magnetic pole occupying angle θ 1  is set in a range of 180°<θ 1 ≦210°.   
     
     
         6 . The motor according to  claim 5 , wherein the magnetic pole occupying angle θ 1  is set in a range of 184°≦θ 1 ≦202°. 
     
     
         7 . The motor according to  claim 6 , wherein the magnetic pole occupying angle θ 1  is set in a range of 188°≦θ 1 ≦198°. 
     
     
         8 . The motor according to  claim 5 , wherein a clearance is formed between the magnet and the salient pole that are adjacent to each other in the circumferential direction of the rotor; and
 the initiating point and the terminating point of each of the magnetic pole occupying angles θ 1  and θ 2  is a median point in the circumferential direction of the clearance.   
     
     
         9 . A motor comprising:
 a rotor including a rotor core, a plurality of magnets arranged along a circumferential direction of the rotor core to function as first magnetic poles, and salient poles formed integrally with the rotor core and arranged between adjacent ones of the magnets in the circumferential direction to function as second magnetic poles; and   a stator arranged facing toward the rotor and including a plurality of slots;   wherein the magnets and salient poles each have a quantity in which the quantities sum together to a quantity x 1  of magnetic pole portions of the rotor, and the slots are in a quantity x 2 , in which a ratio x 1 :x 2  of the quantity of the magnetic pole portions to the quantity of the slots is 3n+1:3n (n being an odd number) or 3n+2:3n (n being an even number);   when an electrical angle corresponding to an angular range from an initiating point, which is set between each magnet and the salient pole that is adjacent to one side of the magnet in the circumferential direction, to a terminating point, which is set between the magnet and the salient pole that is adjacent to the other side of the magnet in the circumferential direction, is defined as a magnetic pole occupying angle θ 1  of each of the magnets, and an electrical angle corresponding to an angular range between the initiating point and the terminating point on two sides of each salient pole in the circumferential direction is defined as a magnetic pole occupying angle θ 2  of each of the salient poles, a sum of the magnetic pole occupying angle θ 1  and the magnetic pole occupying angle θ 2  is 360°; and   the magnetic pole occupying angle θ 1  is set in a range of 180°<θ 1 ≦200°.   
     
     
         10 . The motor according to  claim 9 , wherein the magnetic pole occupying angle θ 1  is set in a range of 182°≦θ 1 ≦197°. 
     
     
         11 . The motor according to  claim 10 , wherein the magnetic pole occupying angle θ 1  is set in a range of 185°≦θ 1 ≦195°. 
     
     
         12 . The motor according to  claim 9 , wherein a clearance is formed between the magnet and the salient pole that are adjacent to each other in the circumferential direction of the rotor; and
 the initiating point and the terminating point of each of the magnetic pole occupying angles θ 1  and θ 2  is a median point in the circumferential direction of the clearance.   
     
     
         13 . A motor comprising:
 a rotor including a rotor core, a plurality of magnets arranged along a circumferential direction of the rotor core to function as first magnetic poles, and salient poles formed integrally with the rotor core and arranged between adjacent ones of the magnets in the circumferential direction to function as second magnetic poles; and   a stator arranged facing toward the rotor and including a plurality of slots;   wherein the magnets and salient poles each have a quantity in which the quantities sum together to a quantity x 1  of magnetic pole portions of the rotor, and the slots are in a quantity x 2 , in which a ratio x 1 :x 2  of the quantity of the magnetic pole portions to the quantity of the slots is 3n−1:3n (n being an odd number that is greater than or equal to 3) or 3n−2:3n (n being an even number that is greater than or equal to 4);   when an electrical angle corresponding to an angular range from an initiating point, which is set between each magnet and the salient pole that is adjacent to one side of the magnet in the circumferential direction, to a terminating point, which is set between the magnet and the salient pole that is adjacent to the other side of the magnet in the circumferential direction, is defined as a magnetic pole occupying angle θ 1  of each of the magnets, and an electrical angle corresponding to an angular range between the initiating point and the terminating point on two sides of each salient pole in the circumferential direction is defined as a magnetic pole occupying angle θ 2  of each of the salient poles, a sum of the magnetic pole occupying angle θ 1  and the magnetic pole occupying angle θ 2  is 360°; and   the magnetic pole occupying angle θ 1  is set in a range of 180°<θ 1 ≦220°.   
     
     
         14 . The motor according to  claim 13 , wherein a surface of the magnet and a surface of the salient pole lie along the same circumference, and a clearance between each of the surfaces and the stator is set to have a dimension that is the same as a clearance between the other one of the surfaces and the stator. 
     
     
         15 . The motor according to  claim 13 , wherein a clearance is formed between the magnet and the salient pole that are adjacent to each other in the circumferential direction of the rotor; and
 the initiating point and the terminating point of each of the magnetic pole occupying angles θ 1  and θ 2  is a median point in the circumferential direction of the clearance.   
     
     
         16 . A motor comprising:
 a rotor including a rotor core, a plurality of magnets arranged along a circumferential direction of the rotor core to function as first magnetic poles, and salient poles formed integrally with the rotor core and arranged between adjacent ones of the magnets in the circumferential direction to function as second magnetic poles, a first clearance being formed between the magnet and the salient pole that are adjacent to each other in the circumferential direction; and   a stator arranged facing toward the rotor spaced apart by a second clearance in a radial direction;   wherein the second clearance has a shortest radial distance A at locations corresponding to the magnets and a shortest radial distance B at locations corresponding to the salient poles, and a ratio B/A is set in a range of 0.3≦B/A<1.   
     
     
         17 . The motor according to  claim 16 , wherein a radial distance of the second clearance is constant in the circumferential direction at locations corresponding to the magnets and the salient poles. 
     
     
         18 . The motor according to  claim 16 , wherein surfaces of the salient pole facing toward the stator each include a central part in the circumferential direction and two ends in the circumferential direction, the second clearance has the shortest radial distance B at the central part in the circumferential direction and a radial distance C at the two ends in the circumferential direction, and a ratio C/B is set in a range of 2≦C/B≦5. 
     
     
         19 . The motor according to  claim 18 , wherein the surfaces of the salient pole is curved at a constant curvature. 
     
     
         20 . A rotor comprising:
 a rotor core;   a plurality of magnets arranged along a circumferential direction of the rotor core to function as first magnetic poles; and   a salient pole formed integrally with the rotor core and arranged between adjacent ones of the magnets in the circumferential direction to function as a second magnetic pole, a first clearance being formed between the magnets and the salient pole;   wherein at least part of a surface of the salient pole and at least part of surfaces of the magnets lie along a reference circumference, and the surface of at least one of the salient pole and the magnets is gradually spaced apart from the reference circumference towards two circumferential ends of the surface so as to have a convex shape.   
     
     
         21 . The rotor according to  claim 20 , wherein the surface of the salient pole is entirely curved at a constant curvature, and a ratio r 1 /R of a curvature radius r 1  of the surface and a radius R of the reference circumference is set in a range of 0.2≦r 1 /R≦0.8. 
     
     
         22 . The rotor according to  claim 20 , wherein the two circumferential ends of the salient pole each have a round corner, and a ratio r 2 /h of a curvature radius r 2  of the corner and a projecting length h of the salient pole is set in a range of 0.2≦r 2 /h≦0.9. 
     
     
         23 . The rotor according to  claim 22 , wherein the surfaces of the magnets are entirely curved at a constant curvature, and a ratio r 3 /R of a curvature radius r 3  of the surface of the magnet and the radius R of the reference circumference is set in a range of 0.4≦r 3 /R≦0.8. 
     
     
         24 . A motor comprising the rotor according to  claim 20 . 
     
     
         25 . A rotor comprising:
 a rotor core;   a plurality of magnets arranged along a circumferential direction of the rotor core to function as first magnetic poles; and   salient poles formed integrally with the rotor core and arranged between adjacent ones of the magnets in the circumferential direction to function as second magnetic poles, a first clearance being formed between the magnet and the salient pole that are adjacent to each other in the circumferential direction;   wherein the salient poles relatively project outward in a radial direction from the magnets, cover members covering the magnets are hooked to the rotor core between adjacent ones of the salient poles, and the cover members are arranged so as not to project outward in the radial direction from the salient poles.   
     
     
         26 . The rotor according to  claim 25 , wherein the salient poles each have a distal part having a hooking portion, and the cover members are formed from a sheet of a nonmagnetic metal material and hooked to the hooking portion. 
     
     
         27 . The rotor according to  claim 25 , wherein the salient poles each have a basal part having a hooking hole, and the cover members are formed from a sheet of a nonmagnetic metal material and hooked to the hooking hole. 
     
     
         28 . The rotor according to  claim 25 , wherein the cover members are formed from a resin material and molded integrally with the rotor core to cover the magnets. 
     
     
         29 . A motor comprising the rotor according to  claim 25 .