Motors, fans and air conditioners

Abstract

The electric motor (1) has a rotor (2) and a stator (3). In a plane orthogonal to the axial direction of the rotor (2), let the width of the surface (22a) of the permanent magnet (22) be M1, let the maximum width of the portion of the inner wall (211a) of the first magnet insertion hole (21a) that contacts the surface (22a) be W1, let the minimum width from the first magnet insertion hole (21a) to the second magnet insertion hole (21a) be W2, let the width of the first front end face (311a) of the first tooth (311) be T1, and let the width from the first front end face (311a) to the second front end face (312a) of the second tooth (312) be T2. At this time, the electric motor (1) satisfies W2 < W1 < M1 and T1 < W1 < T1 + 2×T2.

Description

Technical Field

[0001] The present disclosure relates to electric motors. Background Art

[0002] In order to reduce the amount of permanent magnets used in the rotor for the motor, an alternating pole type rotor including a first magnetic pole portion having a first polarity and a second magnetic pole portion which is a virtual magnetic pole having a second polarity is used. For example, in the alternating pole type rotor described in Patent Document 1, in order to increase the average magnetic flux density between the stator and the rotor, the occupation angle of the first magnetic pole portion having the first polarity and the occupation angle of the second magnetic pole portion which is a virtual magnetic pole having the second polarity are set.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2004-201406 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the technology disclosed in Patent Document 1, a hole in which a permanent magnet is arranged is connected to a gap adjacent to the hole. According to this structure, the leakage flux passing through the area between the hole in which the permanent magnet is arranged and the gap is reduced. That is, the leakage flux flowing from the N pole of the permanent magnet to the S pole of the permanent magnet is reduced. However, in the prior art, leakage flux other than the effective flux flowing from the alternating pole rotor to the object tooth of the stator is not considered. That is, the leakage flux flowing into the teeth adjacent to the object tooth is not considered. For this reason, in the prior art, even if a large permanent magnet is arranged in the alternating pole rotor, the flux from the permanent magnet cannot be effectively used.

[0008] An object of the present disclosure is to increase the effective magnetic flux flowing from the permanent magnet of the alternating-pole rotor to the mating teeth of the stator and to reduce the leakage magnetic flux flowing into the teeth adjacent to the mating teeth.

[0009] Means for solving problems

[0010] An electric motor according to one embodiment of the present disclosure includes an alternating-pole rotor and a stator.

[0011] The alternating-pole rotor includes: a rotor core having a first magnet insertion hole and a second magnet insertion hole adjacent to the first magnet insertion hole; a permanent magnet disposed in the first magnet insertion hole; a first magnetic pole region functioning as a first magnetic pole; and a second magnetic pole region formed by a portion of the rotor core between the first magnet insertion hole and the second magnet insertion hole and functioning as a virtual magnetic pole, i.e., a second magnetic pole.

[0012] The stator includes: a core back portion extending circumferentially; a first tooth extending radially in a first direction from the core back portion and facing the first radially extending portion of the alternating-pole type rotor; and a second tooth adjacent to the first tooth, the stator being disposed outside the alternating-pole type rotor,

[0013] The inner wall of the first magnet insertion hole facing the inner side of the first radial direction contacts the surface of the permanent magnet facing the outer side of the first radial direction,

[0014] Let the width of the surface of the permanent magnet in the long side direction in a plane orthogonal to the axial direction of the alternating-pole type rotor be M1,

[0015] Let the maximum width of the portion of the inner wall of the first magnet insertion hole that contacts the surface of the permanent magnet in the plane be W1,

[0016] Let the minimum width from the first magnet insertion hole to the second magnet insertion hole in the plane be W2,

[0017] Let the width of the first front end face of the first tooth facing the rotor core in a first direction orthogonal to the first radial direction in the plane be T1,

[0018] Let the width in the first direction from the first front end face to the second front end face of the second tooth facing the rotor core be T2. At this time, the following conditions are satisfied:

[0019] W2 < W1 < M1 and T1 < W1 < T1 + 2×T2,

[0020] The first magnet insertion hole includes: a magnet arrangement portion in which the permanent magnet is arranged; and a gap communicating with the magnet arrangement portion in the long side direction of the permanent magnet and facing the second tooth,

[0021] When the magnetic pole center line passing through the magnetic pole center of the first magnetic pole in the plane coincides with the first radial direction,

[0022] Let the width of the portion of the gap facing the second front end face in a direction orthogonal to the second radial direction in which the second tooth extends from the core back portion in the plane be FB2, and let the width of the gap facing the second tooth in the direction orthogonal to the second radial direction in the plane be FB1. At this time, the following conditions are satisfied:

[0023] FB1 > FB2.

[0024] A motor according to other aspects of the present disclosure includes an alternating-pole type rotor and a stator,

[0025] The alternating-pole rotor includes: a rotor core having a first magnet insertion hole and a second magnet insertion hole adjacent to the first magnet insertion hole; a permanent magnet disposed in the first magnet insertion hole; a first magnetic pole region functioning as a first magnetic pole; and a second magnetic pole region formed by a portion of the rotor core between the first magnet insertion hole and the second magnet insertion hole and functioning as a virtual magnetic pole, i.e., a second magnetic pole.

[0026] The stator includes: a core back portion extending in a circumferential direction; a first tooth extending from the core back portion in a first radial direction of the alternating-pole rotor; and a second tooth adjacent to the first tooth, wherein the stator is arranged outside the alternating-pole rotor.

[0027] The inner wall of the first magnet insertion hole facing the inner side in the first radial direction is in contact with the surface of the permanent magnet facing the outer side in the first radial direction.

[0028] The width of the surface of the permanent magnet in the long side direction in a plane orthogonal to the axial direction of the alternating-pole rotor is defined as M1.

[0029] The maximum width of a portion of the inner wall of the first magnet insertion hole in contact with the surface of the permanent magnet in the plane is defined as W1.

[0030] The minimum width from the first magnet insertion hole to the second magnet insertion hole in the plane is defined as W2.

[0031] The width of the first front end surface of the first tooth facing the rotor core in the first direction orthogonal to the first radial direction in the plane is denoted as T1,

[0032] The width in the first direction from the first front end surface to the second front end surface of the second tooth facing the rotor core is defined as T2,

[0033] The angle at which two straight lines passing through two points forming the maximum width W1 in the plane intersect at the rotation center of the alternating-pole rotor is defined as θW1.

[0034] The angle at which two straight lines passing through two points forming the minimum width W2 in the plane intersect at the rotation center is set to θW2,

[0035] The angle at which two straight lines passing through two points forming the width M1 in the plane intersect at the rotation center is defined as θM1.

[0036] The angle at which two straight lines passing through two points forming the width T1 in the plane intersect at the rotation center is defined as θT1.

[0037] The angle at which two straight lines passing through two points forming the width T2 in the plane intersect at the rotation center is set to θT2. At this time, the following is satisfied:

[0038] θW2<θW1<θM1 and θT1<θW1<θT1+2×θT2,

[0039] The first magnet insertion hole includes: a magnet placement portion where the permanent magnet is placed; and a gap that is connected to the magnet placement portion in the long side direction of the permanent magnet and faces the second tooth.

[0040] When the magnetic pole center line passing through the magnetic pole center of the first magnetic pole in the plane coincides with the first radial direction,

[0041] The width of the portion of the gap facing the second front end surface in the plane in a direction perpendicular to the second radial direction extending from the core back portion of the second tooth is set as FB2, and the width of the gap facing the second tooth in the direction perpendicular to the second radial direction in the plane is set as FB1, at this time, the following is satisfied:

[0042] FB1>FB2.

[0043] A fan according to another aspect of the present disclosure includes:

[0044] blades; and

[0045] The electric motor drives the blades.

[0046] Another aspect of the present disclosure provides an air conditioner comprising:

[0047] Indoor unit; and

[0048] an outdoor unit connected to the indoor unit,

[0049] The indoor unit, the outdoor unit, or both the indoor unit and the outdoor unit include the electric motor.

[0050] Effects of the Invention

[0051] According to the present disclosure, it is possible to increase the effective magnetic flux flowing from the permanent magnet of the alternating-pole rotor to the mating teeth of the stator, and reduce the leakage magnetic flux flowing into the teeth adjacent to the mating teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a partial cross-sectional view schematically showing the structure of the electric motor according to the first embodiment.

[0053] Figure 2 It is a cross-sectional view schematically showing the structure of the motor.

[0054] Figure 3 It is a cross-sectional view schematically showing the structure of a rotor.

[0055] Figure 4 It is a cross-sectional view schematically showing the structure of a rotor.

[0056] Figure 5 Yes means Figure 2 A diagram of a portion of an electric motor is shown.

[0057] Figure 6 Yes means Figure 5 Diagram of the motor shown.

[0058] Figure 7 It is a cross-sectional view showing a motor according to a comparative example.

[0059] Figure 8 This is a graph showing the relationship between the ratio of the width of the gap facing the second front end surface to the width of the first front end surface and the cogging torque generated in the motor.

[0060] Fig. 9 It is a graph showing the relationship between the ratio of the width of the gap facing the second front end face to the width of the first front end face and the cogging torque, and the relationship between the ratio of the width of the gap facing the second front end face to the width of the first front end face and the torque of the motor.

[0061] Fig.10 The graph shows the relationship between the ratio θFB2 / θT1 of the angle θFB2 corresponding to the width FB2 to the angle θT1 corresponding to the width T1 and the cogging torque, and the relationship between the ratio θFB2 / θT1 of the angle θFB2 corresponding to the width FB2 to the angle θT1 corresponding to the width T1 and the torque of the motor 1 .

[0062] Fig.11 This is a diagram schematically showing the structure of a fan according to the second embodiment.

[0063] Fig.12 This is a diagram schematically showing the configuration of an air conditioner according to Embodiment 3.

[0064] Fig.13 This is a diagram schematically showing main components in an outdoor unit that is a blower of an air conditioner. DETAILED DESCRIPTION

[0065] Implementation method 1.

[0066] The electric motor 1 according to the first embodiment will be described.

[0067] In the xyz orthogonal coordinate system shown in each figure, the z-axis direction (z-axis) represents the direction parallel to the axis Ax of the motor 1, the x-axis direction (x-axis) represents the direction orthogonal to the z-axis direction (z-axis), and the y-axis direction (y-axis) represents the direction orthogonal to both the z-axis direction and the x-axis direction. The axis Ax is the rotation center of the rotor 2, that is, the rotation axis of the rotor 2. The direction parallel to the axis Ax is also referred to as the "axial direction of the rotor 2" or simply the "axial direction". The radial direction is the radial direction of the rotor 2 or the stator 3, and is a direction orthogonal to the axis Ax. The xy plane is a plane orthogonal to the axial direction. Arrow D1 represents the circumferential direction centered on the axis Ax. The circumferential direction of the rotor 2 or the stator 3 is also simply referred to as the "circumferential direction".

[0068] 〈Motor 1〉

[0069] Figure 1 This is a partial cross-sectional view schematically showing the structure of the electric motor 1 according to the first embodiment.

[0070] Figure 2 It is a cross-sectional view schematically showing the structure of the electric motor 1 .

[0071] The motor 1 includes a rotor 2, a stator 3, a circuit board 4, a molded resin 5, and bearings 7a and 7b that rotatably hold the rotor 2. The motor 1 is a permanent magnet synchronous motor such as an internal permanent magnet motor (IPM motor).

[0072] 〈Stator 3〉

[0073] The stator 3 is arranged outside the rotor 2. The stator 3 includes a stator core 31, a coil 32, and an insulator 33. The stator core 31 is an annular core including a core back portion 31a extending in the circumferential direction and a plurality of teeth 31b extending in the radial direction from the core back portion 31a.

[0074] The stator core 31 is composed of, for example, a plurality of thin iron plates having magnetism. In the present embodiment, the stator core 31 is composed of a plurality of electromagnetic steel plates stacked in the axial direction. The thickness of each electromagnetic steel plate of the stator core 31 is, for example, 0.2 mm to 0.5 mm.

[0075] The coil 32 (ie, winding) is wound around an insulator 33 mounted on the stator core 31. The coil 32 is insulated by the insulator 33. The coil 32 is made of a material containing copper or aluminum, for example.

[0076] The insulator 33 is made of insulating resin such as polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), liquid crystal polymer (LCP), or polyethylene terephthalate (PET). The insulator 33 made of resin is, for example, an insulating film having a thickness of 0.035 mm to 0.4 mm.

[0077] For example, the insulator 33 is integrally molded with the stator core 31. However, the insulator 33 may be molded separately from the stator core 31. In this case, after the insulator 33 is molded, the insulator 33 is fitted to the stator core 31.

[0078] In the present embodiment, the stator core 31, the coil 32, and the insulator 33 are covered by the molded resin 5. The stator core 31, the coil 32, and the insulator 33 may also be fixed by, for example, a cylindrical shell made of a material containing iron. In this case, for example, the stator 3 is covered by the cylindrical shell together with the rotor 2 by shrink fitting.

[0079] The circuit board 4 is fixed together with the stator 3 by the mold resin 5. The circuit board 4 has a driving element for controlling the motor 1.

[0080] The mold resin 5 integrates the circuit board 4 and the stator 3. The mold resin 5 is, for example, a thermosetting resin such as an unsaturated polyester resin (BMC) or an epoxy resin.

[0081] 〈Rotor 2〉

[0082] Figure 3 as well as Figure 4 It is a cross-sectional view schematically showing the structure of the rotor 2 . Figure 3 The illustrated “N” indicates an N pole of the rotor 2 (specifically, an N pole that functions with respect to the stator 3 ), and “S” indicates an S pole of the rotor 2 (specifically, an S pole that functions with respect to the stator 3 ).

[0083] The rotor 2 has a rotor core 21, a plurality of permanent magnets 22, a shaft 23, and a non-magnetic member 24. The rotor 2 is rotatably arranged inside the stator 3. Specifically, the rotor 2 is arranged inside the stator 3 so that each permanent magnet 22 faces the stator 3. The rotation axis of the rotor 2 coincides with the axis Ax. An air gap is provided between the rotor core 21 and the stator 3.

[0084] The rotor core 21 is composed of a plurality of cores 210 stacked in the axial direction. The rotor core 21 (i.e., the plurality of cores 210) is fixed to the non-magnetic member 24. The rotor core 21 may also be fixed to the shaft 23. The shaft 23 is rotatably held by the bearings 7a and 7b. When the motor 1 is driven, the rotor core 21 rotates together with the shaft 23.

[0085] The rotor core 21 may be longer in the axial direction than the stator core 31 . Thus, the magnetic flux from the rotor 2 (specifically, each permanent magnet 22 ) flows into the stator core 31 efficiently.

[0086] The rotor core 21 (ie, the plurality of cores 210 ) has a plurality of magnet insertion holes 21 a and a shaft insertion hole 21 b .

[0087] In the present embodiment, the rotor core 21 has a plurality of magnet insertion holes 21 a , and at least one permanent magnet 22 is disposed in each magnet insertion hole 21 a .

[0088] The rotor core 21 is composed of, for example, a plurality of electromagnetic steel sheets. In this case, each of the plurality of cores 210 is an electromagnetic steel sheet. However, the plurality of cores 210 may include cores other than electromagnetic steel sheets. For example, the rotor core 21 may be composed of a plurality of iron cores having a predetermined shape, or may be composed of a mixture of a soft magnetic material and a resin.

[0089] Each core 210 of the rotor core 21 has a thickness of, for example, 0.2 mm to 0.5 mm. The cores 210 of the rotor core 21 are stacked in the axial direction.

[0090] A plurality of magnet insertion holes 21a are formed at equal intervals in the circumferential direction of the rotor core 21. In the present embodiment, five magnet insertion holes 21a are provided in the rotor core 21. Each magnet insertion hole 21a includes a magnet placement portion 21c in which at least one permanent magnet 22 is placed, and two gaps 21d communicating with the magnet placement portion 21c in the longitudinal direction of the permanent magnet 22.

[0091] The shaft insertion hole 21b is provided in the center portion of the rotor core 21. The shaft insertion hole 21b penetrates the rotor core 21 in the axial direction. The shaft 23 is arranged in the shaft insertion hole 21b.

[0092] The rotor 2 is an alternating pole rotor. That is, the rotor 2 has a first magnetic pole formed by each permanent magnet 22 and a second magnetic pole which is a virtual magnetic pole formed by a portion of the rotor core 21 between two adjacent magnet insertion holes 21a. That is, the second magnetic pole is a virtual magnetic pole formed by a portion of the rotor core 21 adjacent to each magnet insertion hole 21a in the circumferential direction of the rotor core 21.

[0093] like Figure 4As shown, the rotor 2 has a plurality of first magnetic pole regions N1 and a plurality of second magnetic pole regions S1. Each first magnetic pole region N1 is a region that includes at least a portion of the permanent magnet 22 and at least a portion of the magnet insertion hole 21a in the xy plane. Specifically, each first magnetic pole region N1 is a region located between two straight lines passing through the two ends of the surface 22a of the permanent magnet 22 that contacts the inner wall 211a of the magnet insertion hole 21a facing the inner side in the radial direction and the rotation center of the rotor 2 in the xy plane. Each second magnetic pole region S1 is a region located between two straight lines passing through one end of each of two adjacent magnet insertion holes 21a and the rotation center of the rotor 2 in the xy plane. That is, each second magnetic pole region S1 is a region that does not include the magnet insertion hole 21a and the permanent magnet 22.

[0094] The region between each first magnetic pole region N1 and each second magnetic pole region S1 is an inter-pole region.

[0095] Each permanent magnet 22 forms an N pole as the first magnetic pole of the rotor 2. A portion of the rotor core 21 adjacent to each magnet insertion hole 21a in the circumferential direction of the rotor core 21 forms an S pole as a virtual magnetic pole of the rotor 2, that is, a second magnetic pole. In this case, each first magnetic pole region N1 functions as a first magnetic pole (a magnetic pole that functions as an N pole relative to the stator 3 in the present embodiment), and each second magnetic pole region S1 functions as a second magnetic pole (a virtual magnetic pole that functions as an S pole relative to the stator 3 in the present embodiment). In other words, each first magnetic pole region N1 functions as a first polarity, and each second magnetic pole region S1 functions as a second polarity different from the first polarity.

[0096] The number of permanent magnets 22 is half the number n (n is an even number greater than 4) of magnetic poles of the rotor 2. The number n of magnetic poles of the rotor 2 is the sum of the number of magnetic poles that function as N poles relative to the stator 3 and the number of magnetic poles that function as S poles relative to the stator 3. The N poles and S poles of the rotor 2 are alternately located in the circumferential direction of the rotor 2. In the present embodiment, n=10.

[0097] The shaft 23 is fixed to the rotor core 21 by, for example, a non-magnetic member 24 . The non-magnetic member 24 is disposed in the shaft insertion hole 21 b . The non-magnetic member 24 couples the shaft 23 to the rotor core 21 .

[0098] The non-magnetic member 24 is made of a non-magnetic material such as austenitic stainless steel, aluminum, unsaturated polyester resin (Bulk Molding Compound: BMC), polybutylene terephthalate (Poly Butylene Terephthalate: PBT), polyphenylene sulfide (Poly Phenylene Sulfide: PPS), liquid crystal polymer (Liquid Crystal Polymer: LCP), and polyethylene terephthalate (Poly Ethylene Terephthalate: PET).

[0099] The non-magnetic member 24 is, for example, a resin. In this case, the non-magnetic member 24 is made of a non-magnetic resin such as unsaturated polyester resin (BMC), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), liquid crystal polymer (LCP), or polyethylene terephthalate (PET).

[0100] Each permanent magnet 22 is, for example, a flat permanent magnet. Each permanent magnet 22 is, for example, a rare earth magnet containing neodymium or samarium. The permanent magnet 22 may also be a ferrite magnet containing iron. The type of the permanent magnet 22 is not limited to the example of this embodiment, and the permanent magnet 22 may also be formed of other materials.

[0101] The permanent magnets 22 in the magnet insertion holes 21 a are magnetized in the radial direction, and thereby magnetic fluxes from the permanent magnets 22 flow into the stator 3 .

[0102] Figure 5 Yes means Figure 2 A diagram of a portion of an electric motor 1 is shown.

[0103] exist Figure 5 In the diagram, the magnet insertion hole in the middle of the three magnet insertion holes is referred to as the "first magnet insertion hole 211", the magnet insertion hole on the right side is referred to as the "second magnet insertion hole 212", and the magnet insertion hole on the left side is referred to as the "third magnet insertion hole 213". That is, in the xy plane, the second magnet insertion hole 212 and the third magnet insertion hole 213 are adjacent to the first magnet insertion hole 211.

[0104] As reference Figure 4 As described, in Figure 5 In the rotor core 21 shown in FIG. 1 , the region in contact with the permanent magnet 22 is a first magnetic pole region N1 that functions as a first magnetic pole. Figure 5 In the rotor core 21 shown in the figure, the region between the first magnet insertion hole 211 and the second magnet insertion hole 212 is a second magnetic pole region S1 that functions as a virtual magnetic pole, that is, a second magnetic pole.

[0105] exist Figure 5 , the tooth facing the first magnet insertion hole 211 is referred to as the "first tooth 311", the tooth located on the right side of the first tooth 311 is referred to as the "second tooth 312", and the tooth located on the left side of the first tooth 311 is referred to as the "third tooth 313". That is, in the xy plane, the second tooth 312 and the third tooth 313 are adjacent to the first tooth 311.

[0106] Each tooth 31b has a front end surface facing the rotor core 21. Figure 5 In the example shown, the first tooth 311 has a front end surface 311a facing the rotor core 21, the second tooth 312 has a front end surface 312a facing the rotor core 21, and the third tooth 313 has a front end surface 313a facing the rotor core 21. The front end surface 311a of the first tooth 311 is also referred to as "first front end surface 311a", the front end surface 312a of the second tooth 312 is also referred to as "second front end surface 312a", and the front end surface 313a of the third tooth 313 is also referred to as "third front end surface 313a".

[0107] exist Figure 5 In the xy plane shown, the direction in which the first teeth 311 extend is called a “first radial direction”, the direction in which the second teeth 312 extend is called a “second radial direction”, and the direction in which the third teeth 313 extend is called a “third radial direction”.

[0108] In the xy plane, the magnetic pole center line C1 indicating the center of the first magnetic pole passes through the center of the permanent magnet 22. Figure 5 As shown in FIG. 1 , in the xy plane, a magnetic pole center line C1 passing through the magnetic pole center of the first magnetic pole coincides with the first radial direction. In this case, the first magnet insertion hole 211 and the first teeth 311 face each other.

[0109] One of the two gaps 21 d of each magnet insertion hole 21 a faces the second teeth 312 , and the other faces the third teeth 313 .

[0110] An inner wall 211 a of the first magnet insertion hole 211 facing inward in the first radial direction is in contact with a surface 22 a of the permanent magnet 22 facing outward in the first radial direction.

[0111] The width M1 is the width of the surface 22a of the permanent magnet 22 in the long side direction in the xy plane. Figure 5 In the example shown, the width M1 is the width of the surface 22 a in the first direction perpendicular to the magnetic pole center line C1 .

[0112] The width W1 is the maximum width of the portion of the inner wall 211a of the first magnet insertion hole 211 that contacts the surface 22a of the permanent magnet 22 in the xy plane. In the present embodiment, the relationship between the width M1 and the width W1 is: <M1。

[0113] The width W2 is the minimum width in the xy plane from the first magnet insertion hole 211 to the second magnet insertion hole 212.

[0114] The width T1 is the width of the first front end face 311a of the first tooth 311 in the first direction orthogonal to the first radial direction in the xy plane. As described above, in Figure 5 the first direction is still the direction orthogonal to the magnetic pole center line C1.

[0115] The width T2 is the width in the first direction from the first front end face 311a to the second front end face 312a. The width T3 is the width in the first direction from the first front end face 311a to the third front end face 313a. In the present embodiment, T2 = T3. The width in the first direction from the second front end face 312a to the third front end face 313a is T2 + T1 + T3 = T1 + 2×T2.

[0116] In Figure 5 the example shown, the motor 1 satisfies W2 < W1 < M1, and T1 < W1 < T1 + 2×T2.

[0117] Regarding the gap 21d facing the second tooth 312, the width FB1 is the width of the gap 21d in the second direction orthogonal to the second radial direction in the xy plane. Regarding the gap 21d facing the second tooth 312, the width FB2 is the width of the portion of the gap 21d facing the second front end face 312a in the second direction orthogonal to the second radial direction in the xy plane. In Figure 5 the example shown, regarding the gap 21d facing the second tooth 312, the relationship between the width FB1 and the width FB2 is FB1 > FB2.

[0118] Similarly, regarding the gap 21d facing the third tooth 313, the width FB3 is the width of the gap 21d in the third direction orthogonal to the third radial direction in the xy plane. Regarding the gap 21d facing the third tooth 313, the width FB4 is the width of the portion of the gap 21d facing the third front end face 313a in the third direction orthogonal to the third radial direction in the xy plane. In Figure 5 the example shown, regarding the gap 21d facing the third tooth 313, the relationship between the width FB3 and the width FB4 is FB3 > FB4.

[0119] In the present embodiment, the width FB1 of the gap 21d facing the second tooth 312 is equal to the width FB3 of the gap 21d facing the third tooth 313, and the width FB2 of the gap 21d facing the second front end face 312a is equal to the width FB4 of the gap 21d facing the third front end face 313a.

[0120] Figure 6Yes means Figure 5 The electric motor 1 is shown in FIG.

[0121] exist Figure 6 In the example shown, the motor 1 satisfies θW2<θW1<θM1, and θT1<θW1<θT1+2×θT2.

[0122] Angles θW2, θW1, θM1, θT1, and θT2 represent Figure 5 The angles corresponding to the widths W2, W1, M1, T1, and T2 are shown.

[0123] Specifically, the angle θW2 is an angle at which two straight lines respectively passing through two points forming the width W2 (the two ends of the width W2) intersect at the rotation center of the rotor 2 in the xy plane. That is, the angle θW2 is an angle formed by a straight line passing through one end of the width W2 and the rotation center of the rotor 2 and a straight line passing through the other end of the width W2 and the rotation center of the rotor 2 in the xy plane.

[0124] Angle θW1 is an angle at which two straight lines passing through two points forming width W1 in the xy plane intersect at the rotation center of rotor 2. That is, angle θW1 is an angle formed by a straight line passing through one end of width W1 and the rotation center of rotor 2 and a straight line passing through the other end of width W1 and the rotation center of rotor 2 in the xy plane.

[0125] Angle θM1 is an angle at which two straight lines passing through two points forming width M1 in the xy plane intersect at the rotation center of rotor 2. That is, angle θM1 is an angle formed by a straight line passing through one end of width M1 and the rotation center of rotor 2 and a straight line passing through the other end of width M1 and the rotation center of rotor 2 in the xy plane.

[0126] Angle θT1 is an angle at which two straight lines respectively passing through two points forming width T1 in the xy plane intersect at the rotation center of the rotor 2. That is, angle θT1 is an angle formed by a straight line passing through one end of width T1 and the rotation center of the rotor 2 and a straight line passing through the other end of width T1 and the rotation center of the rotor 2 in the xy plane.

[0127] Angle θT2 is an angle at which two straight lines respectively passing through two points forming width T2 in the xy plane intersect at the rotation center of the rotor 2. That is, angle θT2 is an angle formed by a straight line passing through one end of width T2 and the rotation center of the rotor 2 and a straight line passing through the other end of width T2 and the rotation center of the rotor 2 in the xy plane.

[0128] Similarly, the angle θFB2 represents the Figure 5The angle corresponding to the width FB2 shown. Specifically, the angle θFB2 is the angle at which two straight lines passing through two points forming the width FB2 intersect at the rotation center of the rotor 2 in the xy plane. That is, the angle θFB2 is the angle formed by a straight line passing through one end of the width FB2 and the rotation center of the rotor 2 and a straight line passing through the other end of the width FB2 and the rotation center of the rotor 2 in the xy plane.

[0129] <Advantages of the motor 1>

[0130] Figure 7 It is a cross-sectional view showing the motor 1a of the comparative example.

[0131] In the motor 1a of the comparative example, the rotor 2a is different from the rotor 2 of the motor 1 of the present embodiment. Specifically, the rotor 2a of the motor 1a of the comparative example is not an alternating pole type rotor, but a normal IPM (Interior Permanent Magnet, i.e., built-in permanent magnet) rotor. That is, in the rotor 2a of the motor 1a of the comparative example, permanent magnets 22 that function as the first magnetic pole (e.g., N pole) with respect to the stator 3 and permanent magnets 22 that function as the second magnetic pole (e.g., S pole) with respect to the stator 3 are arranged alternately in the circumferential direction.

[0132] Generally, in an IPM rotor, the larger the width M1 in the long side direction of each permanent magnet, the greater the magnetic force of the permanent magnet and the greater the output of the rotor. However, in a normal rotor that is not an alternating pole type rotor, the maximum width M1 in the long side direction of each permanent magnet in the circumferential direction is specifically limited to L / n (L: circumference of the rotor core, n: number of magnetic poles).

[0133] In contrast, the rotor 2 of the motor 1 of the present embodiment satisfies W2 < W1 < M1 as Figure 5 shown. Therefore, in the rotor 2 of the motor 1 of the present embodiment, compared with the comparative example, the width M1 of the permanent magnet 22 forming the first magnetic pole can be increased. As a result, the efficiency of the rotor 2 can be improved with fewer permanent magnets 22 than in the comparative example.

[0134] The motor 1 of the present embodiment satisfies T1 < W1 as Figure 5 shown. Therefore, in Figure 5 the example shown, the effective magnetic flux flowing into the first tooth 311, which is the target tooth, from each permanent magnet 22 can be increased.

[0135] When the width W1 is larger than T1 + 2×T2, the magnetic flux from the permanent magnet 22 flows into teeth that are not the target teeth, and the leakage magnetic flux increases. When the width W1 is larger than T1 + 2×T2, for example, in Figure 5In this case, the magnetic flux from the permanent magnet 22 flows into the second tooth 312 and the third tooth 313, and the leakage magnetic flux increases. For the motor 1 according to the present embodiment, as Figure 5 shown, it satisfies W1 < T1 + 2×T2. Therefore, in Figure 5 the example shown, the leakage magnetic flux flowing into the second tooth 312 and the third tooth 313 adjacent to the first tooth 311 as the target tooth can be reduced.

[0136] For the motor 1 according to the present embodiment, it satisfies W2 < W1 < M1, and T1 < W1 < T1 + 2×T2. Therefore, the effective magnetic flux flowing from each permanent magnet 22 into the target tooth can be increased, and the leakage magnetic flux flowing into the teeth adjacent to the target tooth can be reduced.

[0137] When the relationship between the width FB1 and the width FB2 is FB1 > FB2, the leakage magnetic flux flowing from the permanent magnet 22 disposed in the first magnet insertion hole 211 into the second tooth 312 can be reduced. Therefore, the effective magnetic flux flowing from each permanent magnet 22 into the target tooth can be increased, and the leakage magnetic flux flowing into the teeth adjacent to the target tooth can be reduced.

[0138] Figure 8 It is a graph showing the relationship between the ratio FB2 / T1 of the width FB2 of the gap 21d facing the second front end face 312a to the width T1 of the first front end face 311a and the cogging torque generated in the motor 1.

[0139] As Figure 8 shown, it is preferable that the motor 1 satisfies 0.14 < FB2 / T1 < 0.34. According to this structure, the cogging torque in the motor 1 can be reduced. As a result, the vibration and noise caused by the cogging torque in the motor 1 can be reduced.

[0140] Fig. 9 It is a graph showing the relationship between the ratio FB2 / T1 of the width FB2 of the gap 21d facing the second front end face 312a to the width T1 of the first front end face 311a and the cogging torque, and the relationship between the ratio FB2 / T1 of the width FB2 of the gap 21d facing the second front end face 312a to the width T1 of the first front end face 311a and the torque of the motor 1. In Fig. 9 it, the maximum value of the torque is set to 1.000.

[0141] As Fig. 9 shown, it is preferable that the motor 1 satisfies 0.165 < FB2 / T1 < 0.285. According to this structure, while maintaining the maximum torque of the motor 1, the cogging torque in the motor 1 can be reduced. As a result, while maintaining the maximum torque of the motor 1, the vibration and noise caused by the cogging torque in the motor 1 can be reduced.

[0142] As Fig. 9 shown, it is more preferable that the electric motor 1 satisfies 0.175 < FB2 / T1 < 0.24. According to this structure, a decrease in the maximum torque of the electric motor 1 can be suppressed, and the cogging torque in the electric motor 1 can be effectively reduced. As a result, a decrease in the maximum torque of the electric motor 1 can be suppressed, and the vibration and noise caused by the cogging torque in the electric motor 1 can be effectively reduced.

[0143] Regarding the electric motor 1 of this embodiment, as Figure 6 shown, it satisfies θW2 < θW1 < θM1, and θT1 < θW1 < θT1 + 2×θT2. Therefore, in the example shown in Figure 6 , the effective magnetic flux flowing from each permanent magnet 22 into the target tooth can be increased, and the leakage magnetic flux flowing into the second tooth 312 and the third tooth 313 adjacent to the first tooth 311 which is the target tooth can be reduced.

[0144] Fig.10 is a graph showing the relationship between the ratio θFB2 / θT1 of the angle θFB2 corresponding to the width FB2 to the angle θT1 corresponding to the width T1 and the cogging torque, and the relationship between the ratio θFB2 / θT1 of the angle θFB2 corresponding to the width FB2 to the angle θT1 corresponding to the width T1 and the torque of the electric motor 1. In Fig.10 , the maximum value of the torque is set to 1.000.

[0145] As Fig.10 shown, it is preferable that the electric motor 1 satisfies 0.14 < θFB2 / θT1 < 0.34. According to this structure, the cogging torque in the electric motor 1 can be reduced. As a result, the vibration and noise caused by the cogging torque in the electric motor 1 can be reduced.

[0146] As Fig.10 shown, it is preferable that the electric motor 1 satisfies 0.165 < θFB2 / θT1 < 0.285. According to this structure, while maintaining the maximum torque of the electric motor 1, the cogging torque in the electric motor 1 can be reduced. As a result, while maintaining the maximum torque of the electric motor 1, the vibration and noise caused by the cogging torque in the electric motor 1 can be reduced.

[0147] As Fig.10 shown, it is more preferable that the electric motor 1 satisfies 0.175 < θFB2 / θT1 < 0.24. According to this structure, a decrease in the maximum torque of the electric motor 1 can be suppressed, and the cogging torque in the electric motor 1 can be effectively reduced. As a result, a decrease in the maximum torque of the electric motor 1 can be suppressed, and the vibration and noise caused by the cogging torque in the electric motor 1 can be effectively reduced.

[0148] Embodiment 2.

[0149] Fig.11 This is a diagram schematically showing the structure of a fan 60 according to the second embodiment.

[0150] The fan 60 has blades 61 and a motor 62. The fan 60 is also called a blower. The motor 62 is the motor 1 of Embodiment 1. The blades 61 are fixed to the shaft of the motor 62. The motor 62 drives the blades 61. Specifically, the motor 62 rotates the blades 61. When the motor 62 is driven, the blades 61 rotate and an airflow is generated. Thus, the fan 60 can blow air.

[0151] In the fan 60 according to the second embodiment, since the motor 1 described in the first embodiment is applied to the motor 62, the same advantages as those described in the first embodiment can be obtained. Furthermore, the efficiency of the fan 60 can be prevented from being reduced.

[0152] Implementation method 3.

[0153] An air conditioner 50 (also referred to as a refrigeration air-conditioning device or a refrigeration cycle device) according to Embodiment 3 will be described.

[0154] Fig.12 This is a diagram schematically showing the configuration of an air conditioner 50 according to Embodiment 3.

[0155] Fig.13 This is a diagram schematically showing main components in an outdoor unit 53 which is a blower of the air conditioner 50 .

[0156] The air conditioner 50 according to Embodiment 3 includes an indoor unit 51 as a blower (first blower), a refrigerant pipe 52, and an outdoor unit 53 as a blower (second blower) connected to the indoor unit 51. For example, the outdoor unit 53 is connected to the indoor unit 51 via the refrigerant pipe 52.

[0157] The indoor unit 51 includes a motor 51a (for example, the motor 1 of Embodiment 1), an air supply unit 51b driven by the motor 51a to supply air, and a housing 51c covering the motor 51a and the air supply unit 51b. The air supply unit 51b includes, for example, blades 51d driven by the motor 51a. For example, the blades 51d are fixed to the shaft of the motor 51a to generate airflow.

[0158] The outdoor unit 53 includes a motor 53a (e.g., the motor 1 of Embodiment 1), an air supply unit 53b, a compressor 54, a heat exchanger (not shown), and a housing 53c covering the air supply unit 53b, the compressor 54, and the heat exchanger. The air supply unit 53b is driven by the motor 53a to supply air. The air supply unit 53b includes, for example, a blade 53d driven by the motor 53a. For example, the blade 53d is fixed to the shaft of the motor 53a to generate an air flow. The compressor 54 includes a motor 54a (e.g., the motor 1 of Embodiment 1), a compression mechanism 54b (e.g., a refrigerant circuit) driven by the motor 54a, and a housing 54c covering the motor 54a and the compression mechanism 54b.

[0159] In the air conditioner 50, at least one of the indoor unit 51 and the outdoor unit 53 has the motor 1 described in Embodiment 1. That is, the indoor unit 51, the outdoor unit 53, or both of them have the motor 1 described in Embodiment 1. Specifically, as a driving source of the air supply unit, the motor 1 described in Embodiment 1 is applied to at least one of the motors 51a and 53a. That is, the motor 1 described in Embodiment 1 is applied to the indoor unit 51, the outdoor unit 53, or both of them. The motor 1 described in Embodiment 1 may also be applied to the motor 54a of the compressor 54.

[0160] The air conditioner 50 can perform air conditioning such as cooling operation in which cold air is sent out from the indoor unit 51 or heating operation in which hot air is sent out. In the indoor unit 51, the motor 51a is a driving source for driving the air blower 51b. The air blower 51b can send out conditioned air.

[0161] like Fig.13 As shown, in the outdoor unit 53, the motor 53a is fixed to the housing 53c of the outdoor unit 53 by screws 53e, for example.

[0162] In the air conditioner 50 according to Embodiment 3, since the motor 1 described in Embodiment 1 is applied to at least one of the motors 51a and 53a, the same advantages as those described in Embodiment 1 can be obtained. As a result, the efficiency of the air conditioner 50 can be prevented from being reduced.

[0163] Furthermore, when the motor 1 of the first embodiment is used as a driving source of a blower (e.g., indoor unit 51), the same advantages as those described in the first embodiment can be obtained. As a result, the efficiency of the blower can be prevented from being reduced. The blower having the motor 1 of the first embodiment and the blades (e.g., blades 51d or 53d) driven by the motor 1 can be used alone as a device for blowing air. The blower can also be applied to equipment other than the air conditioner 50.

[0164] Furthermore, when the electric motor 1 according to the first embodiment is used as a driving source of the compressor 54, it is possible to obtain the same advantages as those described in the first embodiment. As a result, it is possible to prevent the efficiency of the compressor 54 from being reduced.

[0165] The electric motor 1 described in the first embodiment can be mounted on a device having a driving source, such as a ventilating fan, a household appliance, or a working machine, in addition to the air conditioner 50 .

[0166] The features of the embodiments described above can be combined with each other as appropriate.

[0167] Description of Reference Numerals

[0168] 1, 51a, 53a, 62: electric motor; 2: rotor; 3: stator; 21: rotor core; 21a: magnet insertion hole; 21b: shaft insertion hole; 22: permanent magnet; 24: non-magnetic component; 50: air conditioner; 51: indoor unit; 53: outdoor unit; 60: fan; 61: blade; 210: core; 311: 1st tooth; 312: 2nd tooth; 313: 3rd tooth; 311a, 312a, 313a: front end surface; N1: 1st magnetic pole region; S1: 2nd magnetic pole region.

Claims

1. A motor, wherein, the motor includes an alternating-pole type rotor and a stator, the alternating-pole type rotor includes: a rotor core having a first magnet insertion hole and a second magnet insertion hole adjacent to the first magnet insertion hole; a permanent magnet disposed in the first magnet insertion hole; a first magnetic pole region functioning as a first magnetic pole; and a second magnetic pole region formed by a part of the rotor core between the first magnet insertion hole and the second magnet insertion hole and functioning as a virtual magnetic pole, i.e., a second magnetic pole, the stator includes: a core back portion extending in the circumferential direction; a first tooth extending in a first radial direction of the alternating-pole type rotor from the core back portion; and a second tooth adjacent to the first tooth, and the stator is disposed outside the alternating-pole type rotor, the inner wall of the first magnet insertion hole facing the inner side of the first radial direction is in contact with the surface of the permanent magnet facing the outer side of the first radial direction, let the width of the surface in the long side direction of the permanent magnet in a plane orthogonal to the axial direction of the alternating-pole type rotor be M1, let the maximum width of the portion of the inner wall of the first magnet insertion hole in the plane that is in contact with the surface of the permanent magnet be W1, let the minimum width from the first magnet insertion hole to the second magnet insertion hole in the plane be W2, let the width of the first tooth facing the first front end surface of the rotor core in a first direction orthogonal to the first radial direction in the plane be T1, let the width in the first direction from the first front end surface to the second front end surface of the second tooth facing the rotor core be T2, and at this time, the following is satisfied: W2 < W1 < M1 and T1 < W1 < T1 + 2×T2, the first magnet insertion hole includes: a magnet arrangement portion in which the permanent magnet is disposed; and a gap communicating with the magnet arrangement portion in the long side direction of the permanent magnet and facing the second tooth, when the magnetic pole center line passing through the magnetic pole center of the first magnetic pole in the plane coincides with the first radial direction, let the width of the portion of the gap in the plane facing the second front end surface in a direction orthogonal to the second radial direction in which the second tooth extends from the core back portion be FB2, and let the width of the gap facing the second tooth in the direction orthogonal to the second radial direction in the plane be FB1, and at this time, the following is satisfied: FB1 > FB2.

2. The motor according to claim 1, wherein, the first magnet insertion hole includes: a magnet arrangement portion in which the permanent magnet is disposed; and a gap communicating with the magnet arrangement portion in the long side direction of the permanent magnet and facing the second tooth, when the magnetic pole center line passing through the magnetic pole center of the first magnetic pole in the plane coincides with the first radial direction, let the width of the portion of the gap in the plane facing the second front end surface in a direction orthogonal to the second radial direction in which the second tooth extends from the core back portion be FB2, and at this time, the following is satisfied: 0.14 <FB2 / T1<0.34。 3. The electric motor according to claim 1, wherein: The first magnet insertion hole includes: a magnet placement portion where the permanent magnet is placed; and a gap communicating with the magnet placement portion in the long side direction of the permanent magnet. When the magnetic pole center line passing through the magnetic pole center of the first magnetic pole in the plane coincides with the first radial direction, Let FB2 be the width of the portion of the gap facing the second front end surface in the direction perpendicular to the second radial direction in which the second tooth extends from the core back portion. In this case, the following is satisfied: 0.165 <FB2 / T1<0.285。 4. The electric motor according to claim 1, wherein: The first magnet insertion hole includes: a magnet placement portion where the permanent magnet is placed; and a gap communicating with the magnet placement portion in the long side direction of the permanent magnet. When the magnetic pole center line passing through the magnetic pole center of the first magnetic pole in the plane coincides with the first radial direction, Let FB2 be the width of the portion of the gap facing the second front end surface in the direction perpendicular to the second radial direction in which the second tooth extends from the core back portion. In this case, the following is satisfied: 0.175 <FB2 / T1<0.24。 5. An electric motor, wherein: The electric motor comprises an alternating-pole rotor and a stator, The alternating-pole rotor includes: a rotor core having a first magnet insertion hole and a second magnet insertion hole adjacent to the first magnet insertion hole; a permanent magnet disposed in the first magnet insertion hole; a first magnetic pole region functioning as a first magnetic pole; and a second magnetic pole region formed by a portion of the rotor core between the first magnet insertion hole and the second magnet insertion hole and functioning as a virtual magnetic pole, i.e., a second magnetic pole. The stator includes: a core back portion extending in a circumferential direction; a first tooth extending from the core back portion in a first radial direction of the alternating-pole rotor; and a second tooth adjacent to the first tooth, wherein the stator is arranged outside the alternating-pole rotor. The inner wall of the first magnet insertion hole facing the inner side in the first radial direction is in contact with the surface of the permanent magnet facing the outer side in the first radial direction. The width of the surface of the permanent magnet in the long side direction in a plane orthogonal to the axial direction of the alternating-pole rotor is defined as M1. The maximum width of a portion of the inner wall of the first magnet insertion hole in contact with the surface of the permanent magnet in the plane is defined as W1. The minimum width from the first magnet insertion hole to the second magnet insertion hole in the plane is defined as W2. The width of the first front end surface of the first tooth facing the rotor core in the first direction orthogonal to the first radial direction in the plane is denoted as T1, The width in the first direction from the first front end surface to the second front end surface of the second tooth facing the rotor core is defined as T2, The angle at which two straight lines passing through two points forming the maximum width W1 in the plane intersect at the rotation center of the alternating-pole rotor is defined as θW1. The angle at which two straight lines passing through two points forming the minimum width W2 in the plane intersect at the rotation center is set to θW2, The angle at which two straight lines passing through two points forming the width M1 in the plane intersect at the rotation center is defined as θM1. The angle at which two straight lines passing through two points forming the width T1 in the plane intersect at the rotation center is defined as θT1. The angle at which two straight lines passing through two points forming the width T2 in the plane intersect at the rotation center is set to θT2. At this time, the following is satisfied: θW2<θW1<θM1 and θT1<θW1<θT1+2×θT2, The first magnet insertion hole includes: a magnet placement portion where the permanent magnet is placed; and a gap that is connected to the magnet placement portion in the long side direction of the permanent magnet and faces the second tooth. When the magnetic pole center line passing through the magnetic pole center of the first magnetic pole in the plane coincides with the first radial direction, The width of the portion of the gap facing the second front end surface in the plane in a direction perpendicular to the second radial direction extending from the core back portion of the second tooth is set as FB2, and the width of the gap facing the second tooth in the direction perpendicular to the second radial direction in the plane is set as FB1, at this time, the following is satisfied: FB1>FB2.

6. The electric motor according to claim 5, wherein: The first magnet insertion hole includes: a magnet placement portion where the permanent magnet is placed; and a gap that is connected to the magnet placement portion in the long side direction of the permanent magnet and faces the second tooth. When the magnetic pole center line passing through the magnetic pole center of the first magnetic pole in the plane coincides with the first radial direction, The width of the portion of the gap facing the second front end surface in the plane in a direction perpendicular to the second radial direction in which the second tooth extends from the core back portion is FB2, The angle at which two straight lines passing through two points forming the width FB2 in the plane intersect at the rotation center is set to θFB2. At this time, the following is satisfied: 0.14<θFB2 / θT1<0.

34.

7. The electric motor according to claim 5, wherein: The first magnet insertion hole includes: a magnet placement portion where the permanent magnet is placed; and a gap communicating with the magnet placement portion in the long side direction of the permanent magnet. When the magnetic pole center line passing through the magnetic pole center of the first magnetic pole in the plane coincides with the first radial direction, The width of the portion of the gap facing the second front end surface in the plane in a direction perpendicular to the second radial direction in which the second tooth extends from the core back portion is FB2, The angle at which two straight lines passing through two points forming the width FB2 in the plane intersect at the rotation center is set to θFB2. At this time, the following is satisfied: 0.165<θFB2 / θT1<0.

285.

8. The electric motor according to claim 5, wherein: The first magnet insertion hole includes: a magnet placement portion where the permanent magnet is placed; and a gap communicating with the magnet placement portion in the long side direction of the permanent magnet. When the magnetic pole center line passing through the magnetic pole center of the first magnetic pole in the plane coincides with the first radial direction, The width of the portion of the gap facing the second front end surface in the plane in a direction perpendicular to the second radial direction in which the second tooth extends from the core back portion is FB2, The angle at which two straight lines passing through two points forming the width FB2 in the plane intersect at the rotation center is set to θFB2. At this time, the following is satisfied: 0.175<θFB2 / θT1<0.

24.

9. A fan, wherein: The fan has: blades; and The electric motor according to any one of claims 1 to 8 for driving the blades.

10. An air conditioner, wherein: The air conditioner comprises: Indoor unit; and an outdoor unit connected to the indoor unit, The indoor unit, the outdoor unit, or both the indoor unit and the outdoor unit include the electric motor according to any one of claims 1 to 8.

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