Electric motors, fans, and air conditioners

Abstract

This motor (1) comprises a rotor (2) having ten magnetic poles, and a stator (3) having nine teeth (31b). The nine teeth (31b) are configured from three teeth groups. The three teeth (31b) of each of the three teeth groups are configured from a center tooth (311), an upstream tooth (312) and a downstream tooth (313). The upstream tooth (312) has an upstream tooth body (312a), and upstream tip (312b) and a downstream tip (312c). In the plane orthogonal to the axial direction, defining LFR as the length of the inner peripheral surface of the upstream tip (312b) along the inner peripheral surface of the upstream tip (312b) of the upstream tooth (312) and LFL as the length of the inner peripheral surface of the downstream tip (312c) along the inner peripheral surface of the downstream tip (312c) of the upstream tooth (312), it holds that LFL > LFR.

Description

[Technical field]

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

[0002] Generally, there is known an electric motor having a rotor with 10 magnetic poles and a stator with 9 teeth. For example, in the electric motor described in Patent Document 1, the width between two teeth corresponding to the same phase is larger than the width between two teeth corresponding to different phases. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-205387 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a conventional electric motor having a rotor with ten magnetic poles and a stator with nine teeth, the loss of effective magnetic flux for rotating the rotor increases, reducing the efficiency of the electric motor.

[0005] An object of the present disclosure is to reduce loss of effective magnetic flux for rotating a rotor in an electric motor having a rotor with 10 magnetic poles and a stator with 9 teeth. [Means for solving the problem]

[0006] The electric motor of the present disclosure comprises: A rotor with 10 magnetic poles. a stator having an annular core back and nine teeth extending from the annular core back toward the rotor; Equipped with The nine teeth are configured into three tooth groups, each group consisting of three teeth adjacent to each other in the circumferential direction, The three teeth groups correspond to a U phase, a V phase, and a W phase, respectively. the three teeth of each of the three tooth groups are composed of a central tooth located in the center of the three teeth, an upstream tooth located upstream of the central tooth in a rotational direction of the rotor, and a downstream tooth located downstream of the central tooth in the rotational direction, The upstream teeth are an upstream teeth body extending from the annular core back toward the rotor; an upstream tip portion facing the rotor and extending from the upstream teeth body toward the upstream side; a downstream tip portion that faces the rotor and extends from the upstream teeth body toward the downstream side; having In a plane perpendicular to the axial direction, when a length of the inner circumferential surface of the upstream tip portion of the upstream tooth along the inner circumferential surface of the upstream tip portion of the upstream tooth is denoted by LFR and a length of the inner circumferential surface of the downstream tip portion of the upstream tooth along the inner circumferential surface of the downstream tip portion of the upstream tooth is denoted by LFL, LFL>LFR Fulfilling The central teeth are a central teeth body extending from the annular core back toward the rotor; an upstream tip portion facing the rotor and extending from the central teeth body toward the upstream side; a downstream tip portion facing the rotor and extending from the central teeth body toward the downstream side; having The central tooth of the three teeth corresponding to the U-phase is defined as a U-phase central tooth, Among the nine teeth, the upstream tooth adjacent to the U-phase central tooth is defined as a U-phase upstream tooth, Among the nine teeth, the downstream tooth adjacent to the U-phase upstream tooth is defined as a V-phase downstream tooth; an angle formed by a line passing through a center of rotation of the rotor and an end portion on the upstream side of the upstream tip portion of the U-phase central tooth on the plane and a line passing through the center of rotation and an end portion on the downstream side of the downstream tip portion of the U-phase upstream tooth on the plane is defined as θ1f; When an angle formed by a line passing through the center of rotation and the upstream end of the upstream tip portion of the U-phase upstream tooth and a line passing through the center of rotation and the downstream end of the downstream tip portion of the V-phase downstream tooth on the plane is defined as θ2b, -18(deg)≦(θ1f-θ2b)<0(deg) Meet death, the stator has an upstream insulator that insulates the upstream teeth, The upstream insulator includes: an upstream insulating portion adjacent to the upstream tip portion of the upstream tooth in the circumferential direction; a downstream insulating portion adjacent to the downstream tip portion of the upstream tooth in the circumferential direction; having a maximum thickness of the upstream insulating portion of the upstream insulator in the circumferential direction on the plane is defined as TFR; When a maximum thickness of the downstream insulating portion of the upstream insulator in the circumferential direction on the plane is TFL, TFL <TFR Meet vinegar. A fan according to another aspect of the present disclosure includes: Feathers and The electric motor that drives the blade; Equipped with. An air conditioner according to another aspect of the present disclosure includes: An indoor unit; an outdoor unit connected to the indoor unit; Equipped with Each of the indoor unit, the outdoor unit, or the indoor unit and the outdoor unit includes the electric motor. Effect of the Invention

[0007] According to the present disclosure, it is possible to reduce loss of effective magnetic flux for rotating a rotor in an electric motor having a rotor with ten magnetic poles and a stator with nine teeth. [Brief description of the drawings]

[0008] [Figure 1] 1 is a partial cross-sectional view that shows a schematic view of an electric motor according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a schematic view of an electric motor in the xy plane. [Diagram 3] FIG. 2 is a cross-sectional view showing a rotor in schematic form. [Figure 4] FIG. 2 is a cross-sectional view showing a schematic view of a stator. [Diagram 5] FIG. 2 is a cross-sectional view showing a schematic view of a stator. [Figure 6] FIG. 4 is a plan view illustrating a schematic structure of each central tooth. [Figure 7] FIG. 4 is a plan view illustrating a schematic structure of each upstream tooth. [Figure 8] FIG. 4 is a plan view illustrating a schematic structure of each downstream tooth. [Figure 9] FIG. 2 is a cross-sectional view showing a schematic view of a stator. [Figure 10] FIG. 2 is a cross-sectional view showing a schematic view of a stator. [Figure 11] FIG. 4 is a plan view illustrating a schematic structure of an insulator attached to each central tooth. [Figure 12] 13 is a plan view illustrating a schematic structure of an insulator attached to each upstream tooth. FIG. [Figure 13] 13 is a plan view illustrating a schematic structure of an insulator attached to each downstream tooth. FIG. [Figure 14] 13 is a graph showing the relationship between θ1f-θ2b (deg) and the induced voltage generated in the electric motor. [Figure 15] 13 is a graph showing the relationship between θ1f-θ2b (deg) and the induced voltage generated in the electric motor. [Figure 16] FIG. 11 is a diagram illustrating a schematic configuration of a fan according to a second embodiment. [Figure 17] FIG. 11 is a diagram illustrating a schematic configuration of an air conditioner according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Embodiment 1 In the xyz Cartesian coordinate system shown in each figure, the z-axis direction (z-axis) indicates a direction parallel to the axis Ax of the electric motor 1, the x-axis direction (x-axis) indicates a direction perpendicular to the z-axis direction, and the y-axis direction (y-axis) indicates a direction perpendicular to both the z-axis direction and the x-axis direction. The axis Ax is the center of rotation of the rotor 2, i.e., 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 as the "axial direction". The radial direction is the radial direction of the rotor 2 or the stator 3, and is a direction perpendicular to the axis Ax. The xy plane is a plane perpendicular to the axial direction. The arrow D10 indicates 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".

[0010] FIG. 1 is a partial cross-sectional view that illustrates a schematic diagram of an electric motor 1 according to a first embodiment. 2 is a cross-sectional view of the electric motor 1 taken along the xy plane. Among the arrows indicated by D10, an arrow D11 indicates the direction of rotation of the rotor 2. Among the arrows indicated by D10, an arrow D12 indicates the direction opposite to the direction of rotation of the rotor 2.

[0011] The electric 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 electric motor 1 is, for example, a permanent magnet synchronous motor (also called a brushless DC motor).

[0012] The bearings 7a and 7b support the rotor 2 so that it can rotate.

[0013] <Rotor 2> The rotor 2 is rotatably disposed inside the stator 3. An air gap exists between the rotor 2 and the stator 3. The rotor 2 rotates about an axis line Ax.

[0014] FIG. 3 is a cross-sectional view that diagrammatically illustrates the rotor 2. As shown in FIG. The rotor 2 has a main magnet 21 and a shaft 23 arranged inside the main magnet 21. A resin 22 may be filled between the main magnet 21 and the shaft 23.

[0015] The main magnet 21 is longer in the axial direction than the stator core 31. This configuration has the advantage that the magnetic flux from the rotor 2 easily flows into both ends of the stator core 31 in the axial direction.

[0016] The main magnet 21 is, for example, a bonded magnet. The rotor 2 may be, for example, a surface permanent magnet (SPM) rotor. In this case, a plurality of permanent magnets are attached to the outer circumferential surface of the rotor core.

[0017] The main magnet 21 has ten magnetic poles arranged in the circumferential direction, so that the rotor 2 has ten magnetic poles.

[0018] An IPM (Interior Permanent Magnet) rotor may be used as the rotor 2. When the rotor 2 is an IPM rotor, for example, permanent magnets are arranged in a plurality of magnet insertion holes formed in the rotor core. When the rotor 2 is an IPM rotor, the rotor core is formed from a plurality of electromagnetic steel plates. In this case, each electromagnetic steel plate has a thickness of, for example, 0.2 mm to 0.5 mm. The electromagnetic steel plates are laminated in the axial direction. However, the rotor core may be a resin core formed by mixing a soft magnetic material and resin, instead of a plurality of electromagnetic steel plates.

[0019] The shaft 23 is inserted into a hole formed in the center of the rotor 2, for example.

[0020] The shaft 23 is integrated with the main magnet 21 by, for example, caulking or a resin 22 such as polybutylene terephthalate (PBT).

[0021] <Stator 3> FIG. 4 is a cross-sectional view that diagrammatically illustrates the stator 3. As shown in FIG.

[0022] The stator 3 is disposed on the outside of the rotor 2. The stator 3 includes a stator core 31, at least one coil 32, and at least one insulator 33.

[0023] The stator core 31 has a core back 31a (also referred to as a yoke) and nine teeth 31b extending from the core back 31a toward the rotor 2. The core back 31a is, for example, an annular core back. Therefore, the stator core 31 is an annular core. In the example shown in Fig. 4, the stator core 31 has nine slots in which the coils 32 are arranged.

[0024] Each of the teeth 31b extends in the radial direction. In other words, each of the teeth 31b extends from the core back 31a toward the center of rotation of the rotor 2.

[0025] The stator core 31 is made of, for example, a plurality of magnetic thin iron plates. The stator core 31 is made of, for example, a plurality of electromagnetic steel plates laminated in the axial direction. Each electromagnetic steel plate is an annular core. The thickness of each electromagnetic steel plate of the stator core 31 is, for example, 0.2 mm to 0.5 mm.

[0026] The coil 32 is a three-phase coil. That is, the coil 32 has three phases: U phase, V phase, and W phase. Each coil 32 is wound around each tooth 31b in concentrated winding.

[0027] In the example shown in FIG. 4, the nine coils 32 are wound around the nine teeth 31b such that the coils 32 wound around three circumferentially adjacent teeth 31b out of the nine teeth 31b form the same phase.

[0028] The coil 32 is wound around an insulator 33 attached to the stator core 31. In this case, the coil 32 is insulated by the insulator 33. The coil 32 is made of a material including, for example, copper or aluminum.

[0029] The insulator 33 is made of insulating resin such as polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), liquid crystal polymer (LCP), polyethylene terephthalate (PET), etc. The insulator 33 made of resin is, for example, an insulating film having a thickness of 0.035 mm to 0.4 mm.

[0030] For example, the insulator 33 is molded integrally with the stator core 31. However, the insulator 33 may be molded separately from the stator core 31. In this case, the insulator 33 is fitted to the stator core 31 after being molded.

[0031] 1, the stator core 31, the coils 32, and the insulators 33 are covered by a molding resin 5. The stator core 31, the coils 32, and the insulators 33 may be fixed by a cylindrical shell made of, for example, a material including iron. In this case, for example, the stator 3, together with the rotor 2, is covered by the cylindrical shell by shrink fitting.

[0032] 1, the circuit board 4 is fixed to the stator 3. The circuit board 4 has a driving element for controlling the electric motor 1.

[0033] 1, the molding resin 5 integrates the circuit board 4 with the stator 3. The molding resin 5 is, for example, a thermosetting resin such as an unsaturated polyester resin (BMC) or an epoxy resin.

[0034] The stator core 31 will now be described in detail. FIG. 5 is a cross-sectional view that diagrammatically illustrates the stator 3. As shown in FIG.

[0035] The nine teeth 31b (in FIG. 5, three central teeth 311, three upstream teeth 312, and three downstream teeth 313, which will be described later) are configured into three teeth groups, each of which consists of three circumferentially adjacent teeth 31b. The three teeth groups correspond, for example, to the first phase, the second phase, and the third phase, respectively. When the coil 32 is a three-phase coil, the three teeth groups correspond to the U phase, the V phase, and the W phase, respectively. In this embodiment, as shown in FIG. 5, the three teeth groups correspond to the U phase, the V phase, and the W phase, respectively.

[0036] In the xy plane, the teeth 31b located in the center of the three teeth 31b in each of the three tooth groups are referred to as the "central teeth 311," the teeth 31b located upstream of the central teeth in the rotation direction D11 of the rotor 2 are referred to as the "upstream teeth 312," and the teeth 31b located downstream of the central teeth in the rotation direction D11 are referred to as the "downstream teeth 313." In other words, the three teeth 31b in each of the three tooth groups are composed of the central teeth 311, the upstream teeth 312, and the downstream teeth 313.

[0037] In each of the three tooth groups, coils 32 forming the same phase are wound around the central teeth 311, the upstream teeth 312, and the downstream teeth 313. That is, when a current flows through the coils 32, the coils 32 wound around the central teeth 311, the coils 32 wound around the upstream teeth 312, and the coils 32 wound around the downstream teeth 313 form the same phase (for example, U phase, V phase, or W phase).

[0038] The central tooth 311 of the three teeth 31b corresponding to the U phase is defined as the "U-phase central tooth". The U-phase central tooth is also referred to as the "U-phase central tooth 311". The upstream tooth 312 of the three teeth 31b corresponding to the U phase is defined as the "U-phase upstream tooth". In other words, the upstream tooth 312 adjacent to the U-phase central tooth 311 of the nine teeth 31b is defined as the "U-phase upstream tooth". The U-phase upstream tooth is also referred to as the "U-phase upstream tooth 312". The downstream tooth 313 of the three teeth 31b corresponding to the U phase is defined as the "U-phase downstream tooth". In other words, the downstream tooth 313 adjacent to the U-phase central tooth 311 of the nine teeth 31b is defined as the "U-phase downstream tooth". The U-phase downstream tooth is also referred to as the "U-phase downstream tooth 313".

[0039] The central tooth 311 of the three teeth 31b corresponding to the V phase is defined as the "V-phase central tooth". The V-phase central tooth is also referred to as the "V-phase central tooth 311". The upstream tooth 312 of the three teeth 31b corresponding to the V phase is defined as the "V-phase upstream tooth". In other words, the upstream tooth 312 adjacent to the V-phase central tooth 311 of the nine teeth 31b is defined as the "V-phase upstream tooth". The V-phase upstream tooth is also referred to as the "V-phase upstream tooth 312". The downstream tooth 313 of the three teeth 31b corresponding to the V phase is defined as the "V-phase downstream tooth". In other words, the downstream tooth 313 adjacent to the V-phase central tooth 311 of the nine teeth 31b is defined as the "V-phase downstream tooth". The V-phase downstream tooth is also referred to as the "V-phase downstream tooth 313".

[0040] The central tooth 311 of the three teeth 31b corresponding to the W phase is defined as the "W-phase central tooth". The W-phase central tooth is also referred to as the "W-phase central tooth 311". The upstream tooth 312 of the three teeth 31b corresponding to the W phase is defined as the "W-phase upstream tooth". In other words, the upstream tooth 312 adjacent to the W-phase central tooth 311 of the nine teeth 31b is defined as the "W-phase upstream tooth". The W-phase upstream tooth is also referred to as the "W-phase upstream tooth 312". The downstream tooth 313 of the three teeth 31b corresponding to the W phase is defined as the "W-phase downstream tooth". In other words, the downstream tooth 313 adjacent to the W-phase central tooth 311 of the nine teeth 31b is defined as the "W-phase downstream tooth". The W-phase downstream tooth is also referred to as the "W-phase downstream tooth 313".

[0041] For example, among the nine teeth 31b, the downstream tooth 313 adjacent to the U-phase upstream tooth 312 is defined as the "V-phase downstream tooth." Among the nine teeth 31b, the upstream tooth 312 adjacent to the U-phase downstream tooth 313 is defined as the "W-phase upstream tooth."

[0042] <Central Teeth 311> FIG. 6 is a plan view that illustrates a schematic structure of each central tooth 311. As shown in FIG. Each central tooth 311 has a central tooth main body 311a, an upstream tip 311b, and a downstream tip 311c. The two dashed lines in Fig. 6 are located on extensions of the side surface of central tooth main body 311a and indicate the boundary between central tooth main body 311a and upstream tip 311b, and the boundary between central tooth main body 311a and downstream tip 311c, respectively.

[0043] The central teeth main body 311a extends from the core back 31a toward the rotor 2. The upstream tip 311b extends from the central teeth main body 311a toward the upstream side in the rotation direction D11 of the rotor 2. The upstream tip 311b faces the rotor 2. The downstream tip 311c extends from the central teeth main body 311a toward the downstream side in the rotation direction D11 of the rotor 2. The downstream tip 311c faces the rotor 2.

[0044] The inner circumferential surface of the upstream tip 311b of the central tooth 311 is the surface of the upstream tip 311b facing the rotor 2. The inner circumferential surface of the downstream tip 311c of the central tooth 311 is the surface of the downstream tip 311c facing the rotor 2. In the xy plane, when the length of the inner circumferential surface of the upstream tip 311b of the central tooth 311 along the inner circumferential surface of the upstream tip 311b of the central tooth 311 is LCR and the length of the inner circumferential surface of the downstream tip 311c of the central tooth 311 along the inner circumferential surface of the downstream tip 311c of the central tooth 311 is LCL, the relationship between the length LCL and the length LCR satisfies LCL = LCR.

[0045] <Upstream teeth 312> FIG. 7 is a plan view that illustrates a schematic structure of each upstream tooth 312. As shown in FIG. Each upstream tooth 312 has an upstream tooth main body 312a, an upstream tip portion 312b, and a downstream tip portion 312c. The two dashed lines in Fig. 7 are located on extensions of the side surface of upstream tooth main body 312a and indicate the boundary between upstream tooth main body 312a and upstream tip portion 312b, and the boundary between upstream tooth main body 312a and downstream tip portion 312c, respectively.

[0046] The upstream teeth main body 312a extends from the core back 31a toward the rotor 2. The upstream tip 312b extends from the upstream teeth main body 312a toward the upstream side in the rotation direction D11 of the rotor 2. The upstream tip 312b faces the rotor 2. The downstream tip 312c extends from the upstream teeth main body 312a toward the downstream side in the rotation direction D11 of the rotor 2. The downstream tip 312c faces the rotor 2.

[0047] An inner circumferential surface of the upstream tip 312b of the upstream tooth 312 is the surface of the upstream tip 312b facing the rotor 2. An inner circumferential surface of the downstream tip 312c of the upstream tooth 312 is the surface of the downstream tip 312c facing the rotor 2. In the xy plane, when the length of the inner circumferential surface of the upstream tip 312b of the upstream tooth 312 along the inner circumferential surface of the upstream tip 312b of the upstream tooth 312 is LFR and the length of the inner circumferential surface of the downstream tip 312c of the upstream tooth 312 along the inner circumferential surface of the downstream tip 312c of the upstream tooth 312 is LFL, the relationship between the length LFL and the length LFR satisfies LFL>LFR.

[0048] <Downstream teeth 313> FIG. 8 is a plan view that illustrates a schematic structure of each downstream tooth 313. As shown in FIG. Each downstream tooth 313 has a downstream tooth main body 313a, an upstream tip portion 313b, and a downstream tip portion 313c. The two dashed lines in Fig. 8 are located on extensions of the side surface of downstream tooth main body 313a, and indicate the boundary between downstream tooth main body 313a and upstream tip portion 313b, and the boundary between downstream tooth main body 313a and downstream tip portion 313c, respectively.

[0049] The downstream tooth body 313a extends from the core back 31a toward the rotor 2. The upstream tip 313b extends upstream in the rotational direction D11 of the rotor 2 from the downstream tooth body 313a. The upstream tip 313b faces the rotor 2. The downstream tip 313c extends downstream in the rotational direction D11 of the rotor 2 from the downstream tooth body 313a. The downstream tip 313c faces the rotor 2.

[0050] The inner peripheral surface of the upstream tip 313b of the downstream tooth 313 is the surface of the upstream tip 313b facing the rotor 2. The inner peripheral surface of the downstream tip 313c of the downstream tooth 313 is the surface of the downstream tip 313c facing the rotor 2. In the xy plane, when the length of the inner peripheral surface of the upstream tip 313b of the downstream tooth 313 along the inner peripheral surface of the upstream tip 313b of the downstream tooth 313 is defined as LBR, and the length of the inner peripheral surface of the downstream tip 313c of the downstream tooth 313 along the inner peripheral surface of the downstream tip 313c of the downstream tooth 313 is defined as LBL, the relationship between the length LBL and the length LBR satisfies LBL < LBR.

[0051] In the stator 3, the three central tooth bodies 311a, the three upstream tooth bodies 312a, and the three downstream tooth bodies 313a are arranged at equal intervals in the circumferential direction.

[0052] FIG. 9 is a cross-sectional view schematically showing the stator 3. The angle θ1f is the angle formed by the straight line L1 and the straight line L2 in the xy plane. The straight line L1 is a straight line passing through the center of rotation of the rotor 2 and the end E1 on the upstream side in the rotational direction D11 of the upstream tip 311b of the U-phase central tooth 311 in the xy plane. The straight line L2 is a straight line passing through the center of rotation of the rotor 2 and the end E2 on the downstream side in the rotational direction D11 of the downstream tip 312c of the U-phase upstream tooth 312 in the xy plane. The definition of the angle θ1f is also applicable to the relationship between the central tooth 311 and the upstream tooth 312 in each of not only the U-phase but also the V-phase and the W-phase.

[0053] Angle θ2b is the angle between lines L3 and L4 in the xy plane. Line L3 is a line passing through the center of rotation of rotor 2 and end E3 on the upstream side in rotation direction D11 of upstream tip 312b of U-phase upstream tooth 312 in the xy plane. Line L4 is a line passing through the center of rotation of rotor 2 and end E4 on the downstream side in rotation direction D11 of downstream tip 313c of V-phase downstream tooth 313 in the xy plane.

[0054] In this case, the relationship between the angle θ1f and the angle θ2b satisfies θ1f<θ2b.

[0055] FIG. 10 is a cross-sectional view that diagrammatically illustrates the stator 3. As shown in FIG. Angle θ1b is an angle between straight lines L5 and L6 in the xy plane. Straight line L5 is a straight line passing through the center of rotation of rotor 2 and end E5 of downstream tip 311c of U-phase central tooth 311 on the downstream side in rotation direction D11 in the xy plane. Straight line L6 is a straight line passing through the center of rotation of rotor 2 and end E6 of upstream tip 313b of U-phase downstream tooth 313 on the upstream side in rotation direction D11 in the xy plane. The definition of angle θ1b is applied not only to the relationship between central teeth 311 and downstream teeth 313 in the U-phase, but also to the relationship between central teeth 311 and downstream teeth 313 in each of the V-phase and W-phase.

[0056] Angle θ3f is the angle between lines L7 and L8 in the xy plane. Line L7 is a line passing through the center of rotation of the rotor 2 and end E7 on the downstream side in the rotation direction D11 of downstream tip 313c of U-phase downstream tooth 313 in the xy plane. Line L8 is a line passing through the center of rotation of the rotor 2 and end E8 on the upstream side in the rotation direction D11 of upstream tip 312b of W-phase upstream tooth 312 in the xy plane.

[0057] In this case, the relationship between the angle θ3f and the angle θ1b satisfies θ3f>θ1b.

[0058] The relationship between the angles θ1f and θ1b satisfies θ1f=θ1b. The relationship between the angles θ2b and θ3f satisfies θ2b=θ3f. Furthermore, in this embodiment, the electric motor 1 satisfies θ1f=θ1b and θ2b=θ3f.

[0059] The definition of angle θ2b or angle θ3f also applies to the relationship between the V-phase upstream teeth 312 and the W-phase downstream teeth 313.

[0060] FIG. 11 is a plan view that illustrates a schematic structure of the insulators 33 attached to the central teeth 311. As shown in FIG. The insulator 33 that insulates the central teeth 311 is also referred to as the “central insulator 33.” The central insulator 33 has an upstream insulating portion 331a adjacent to the upstream tip portion 311b of the central teeth 311 in the circumferential direction, and a downstream insulating portion 331b adjacent to the downstream tip portion 311c of the central teeth 311 in the circumferential direction. The upstream insulating portion 331a and the downstream insulating portion 331b face the rotor 2.

[0061] The thickness TCR is the maximum thickness in the circumferential direction of the upstream insulating portion 331a of the central insulator 33 in the xy plane. The thickness TCL is the maximum thickness in the circumferential direction of the downstream insulating portion 331b of the central insulator 33 in the xy plane. In this case, the relationship between the thickness TCL and the thickness TCR satisfies TCL=TCR.

[0062] For example, in the xy plane, the area of ​​the upstream insulating portion 331a of the central insulator 33 is the same as the area of ​​the downstream insulating portion 331b of the central insulator 33. With this configuration, it is possible to provide equal spaces for arranging the coils 32 provided on both sides of the central teeth main body 311a, and as a result, it is possible to wind a large number of coils 32 evenly around the central teeth main body 311a.

[0063] FIG. 12 is a plan view that illustrates a schematic structure of the insulators 33 attached to the upstream teeth 312. As shown in FIG. The insulator 33 that insulates the upstream teeth 312 is also referred to as the "upstream insulator 33". The upstream insulator 33 has an upstream insulating portion 332a adjacent to the upstream tip portion 312b of the upstream teeth 312 in the circumferential direction and a downstream insulating portion 332b adjacent to the downstream tip portion 312c of the upstream teeth 312 in the circumferential direction. The upstream insulating portion 332a and the downstream insulating portion 332b face the rotor 2.

[0064] The thickness TFR is the maximum thickness of the upstream insulating portion 332a of the upstream insulator 33 in the circumferential direction in the xy plane. The thickness TFL is the maximum thickness of the downstream insulating portion 332b of the upstream insulator 33 in the circumferential direction in the xy plane. In this case, the relationship between the thickness TFL and the thickness TFR satisfies TFL < TFR.

[0065] For example, the area of the upstream insulating portion 332a of the upstream insulator 33 in the xy plane is larger than the area of the downstream insulating portion 332b of the upstream insulator 33. With this configuration, a space for arranging the coils 32 provided on both sides of the upstream tooth body 312a can be provided evenly, and as a result, more coils 32 can be wound evenly around the upstream tooth body 312a.

[0066] FIG. 13 is a plan view schematically showing the structure of the insulator 33 attached to each downstream tooth 313. The insulator 33 that insulates the downstream teeth 313 is also referred to as the "downstream insulator 33". The downstream insulator 33 has an upstream insulating portion 333a adjacent to the upstream tip portion 313b of the downstream teeth 313 in the circumferential direction and a downstream insulating portion 333b adjacent to the downstream tip portion 313c of the downstream teeth 313 in the circumferential direction. The upstream insulating portion 333a and the downstream insulating portion 333b face the rotor 2.

[0067] The thickness TBR is the maximum thickness in the circumferential direction of the upstream insulating portion 333a of the downstream insulator 33 in the xy plane. The thickness TBL is the maximum thickness in the circumferential direction of the downstream insulating portion 333b of the downstream insulator 33 in the xy plane. In this case, the relationship between the thickness TBL and the thickness TBR satisfies TBL>TBR.

[0068] For example, in the xy plane, the area of ​​the downstream insulating portion 333b of the downstream insulator 33 is larger than the area of ​​the upstream insulating portion 333a of the downstream insulator 33. With this configuration, it is possible to provide equal spaces for arranging the coils 32 provided on both sides of the downstream teeth main body 313a, and as a result, it is possible to wind a large number of coils 32 evenly around the downstream teeth main body 313a.

[0069] Advantages of Electric Motor 1 The advantages of the electric motor 1 are explained below. Typically, in an electric motor having a rotor with 10 magnetic poles and a stator with 9 teeth, if the phase of the magnetic flux flowing into the central tooth of each phase is taken as the reference (i.e., 0 deg), the phase difference of the magnetic flux flowing into the upstream tooth adjacent to the central tooth is +20 deg electrical angle, and the phase difference of the magnetic flux flowing into the downstream tooth adjacent to the central tooth is -20 deg electrical angle. In this case, when the magnetic flux flowing into the three teeth in each phase is combined, some of the magnetic flux between the two adjacent teeth cancels out, resulting in a loss of magnetic flux in the electric motor 1.

[0070] In this embodiment, the electric motor 1 satisfies LFL>LFR. Therefore, in each phase, the phase of the magnetic flux flowing into the upstream teeth 312 can be made closer to the phase of the magnetic flux flowing into the central teeth 311. In other words, in each phase, the phase difference of the magnetic flux flowing into the upstream teeth 312 with respect to the phase of the magnetic flux flowing into the central teeth 311 can be made smaller, and the magnetic flux loss in the electric motor 1 can be reduced. As a result, the loss of effective magnetic flux for rotating the rotor 2 in the electric motor 1 can be reduced.

[0071] In the stator 3, the three central tooth bodies 311a, the three upstream tooth bodies 312a, and the three downstream tooth bodies 313a are arranged at equal intervals in the circumferential direction. Therefore, a space for arranging the coil 32 can be provided evenly in the stator 3 in the circumferential direction. As a result, a large number of coils 32 can be wound evenly around these central tooth bodies 311a, upstream tooth bodies 312a, and downstream tooth bodies 313a.

[0072] When the electric motor 1 satisfies LBL < LBR, in each phase, the phase of the magnetic flux flowing into the downstream tooth 313 can be made closer to the phase of the magnetic flux flowing into the central tooth 311. In other words, in each phase, the phase difference of the magnetic flux flowing into the downstream tooth 313 with respect to the phase of the magnetic flux flowing into the central tooth 311 can be reduced, and the magnetic flux loss in the electric motor 1 can be reduced. As a result, the loss of the effective magnetic flux for rotating the rotor 2 in the electric motor 1 can be reduced.

[0073] When the electric motor 1 satisfies θ1f < θ2b, in each phase, the phase of the magnetic flux flowing into the upstream tooth 312 can be made closer to the phase of the magnetic flux flowing into the central tooth 311. In other words, in each phase, the phase difference of the magnetic flux flowing into the upstream tooth 312 with respect to the phase of the magnetic flux flowing into the central tooth 311 can be reduced, and the magnetic flux loss in the electric motor 1 can be reduced. As a result, the loss of the effective magnetic flux for rotating the rotor 2 in the electric motor 1 can be reduced.

[0074] When the electric motor 1 satisfies θ3f>θ1b, the phase of the magnetic flux flowing into the downstream teeth 313 can be made closer to the phase of the magnetic flux flowing into the central teeth 311 in each phase. In other words, the phase difference of the magnetic flux flowing into the downstream teeth 313 relative to the phase of the magnetic flux flowing into the central teeth 311 in each phase can be made smaller, thereby reducing the magnetic flux loss in the electric motor 1. As a result, the loss of effective magnetic flux for rotating the rotor 2 in the electric motor 1 can be reduced.

[0075] When the electric motor 1 satisfies θ1f=θ1b and θ2b=θ3f, the structure of the stator core 31 of each phase is symmetrical about the central tooth 311 in the xy plane. With this configuration, it is possible to reduce singular sounds during rotation of the rotor 2.

[0076] 14 and 15 are graphs showing the relationship between the difference between the angle θ1f and the angle θ2b, ie, "θ1f-θ2b" (deg), and the induced voltage generated in the electric motor 1. In FIG. The vertical axis of the graphs shown in Figures 14 and 15 represents the induced voltage generated in the motor. The induced voltage generated in the motor when θ1f-θ2b=0 is set as a reference value 1. The horizontal axis of the graphs shown in Figures 14 and 15 represents θ1f-θ2b (deg). 14, when the electric motor 1 satisfies -18 (deg)≦(θ1f-θ2b)<0 (deg), the induced voltage is equal to or greater than 1. In this case, the induced voltage generated in the electric motor 1 can be improved compared to a normal electric motor in which the angles θ1f and θ2b are equal.

[0077] 15, when the electric motor 1 satisfies -16 (deg) ≦ (θ1f-θ2b) ≦ -5 (deg), the induced voltage is 1.025 or more. In this case, the induced voltage generated in the electric motor 1 can be further improved compared to a normal electric motor in which the angles θ1f and θ2b are equal.

[0078] As shown in FIG. 12, when the motor 1 satisfies TFL < TFR, even if LFL > LFR or θ1f < θ2b, a space for the coil 32 arranged upstream in the rotational direction D11 with respect to the upstream-side tooth body 312a can be secured. With this configuration, spaces for arranging the coils 32 provided on both sides of the upstream-side tooth body 312a can be provided evenly, and as a result, a large number of coils 32 can be wound evenly around the upstream-side tooth body 312a.

[0079] As shown in FIG. 13, when the motor 1 satisfies TBL > TBR, even if LBL < LBR or θ3f > θ1b, a space for the coil 32 arranged downstream in the rotational direction D11 with respect to the downstream-side tooth body 313a can be secured. With this configuration, spaces for arranging the coils 32 provided on both sides of the downstream-side tooth body 313a can be provided evenly, and as a result, a large number of coils 32 can be wound evenly around the downstream-side tooth body 313a.

[0080] Embodiment 2. FIG. 16 is a diagram schematically showing the fan 60 according to Embodiment 2. The fan 60 has blades 61 and a motor 62. The fan 60 is also referred to as a blower. The blades 61 are formed of, for example, polypropylene (PP) containing glass fiber.

[0081] The motor 62 is the motor 1 according to 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 air flow is generated. Thereby, the fan 60 can blow air.

[0082] In the fan 60 according to Embodiment 2, since the motor 1 described in Embodiment 1 is applied to the motor 62, the same advantages as those described in Embodiment 1 can be obtained. Furthermore, the efficiency of the fan 60 can be increased.

[0083] Embodiment 3 An air conditioner 10 (also referred to as a refrigeration and air conditioning device or a refrigeration cycle device) according to a third embodiment will be described. FIG. 17 is a diagram showing a schematic configuration of an air conditioner 10 according to the third embodiment.

[0084] The air conditioner 10 according to the third embodiment has an indoor unit 11 serving as a blower (also referred to as a first blower) and an outdoor unit 13 serving as a blower (also referred to as a second blower) connected to the indoor unit 11.

[0085] In this embodiment, the air conditioner 10 has an indoor unit 11, a refrigerant pipe 12, and an outdoor unit 13. For example, the outdoor unit 13 is connected to the indoor unit 11 through the refrigerant pipe 12.

[0086] The indoor unit 11 has an electric motor 11a (for example, the electric motor 1 according to the first embodiment), an air blowing section 11b that is driven by the electric motor 11a to blow air, and a housing 11c that covers the electric motor 11a and the air blowing section 11b. The air blowing section 11b has, for example, a blade 11d that is driven by the electric motor 11a. For example, the blade 11d is fixed to a shaft of the electric motor 11a and generates an airflow.

[0087] The outdoor unit 13 has an electric motor 13a (for example, the electric motor 1 according to the first embodiment), a blower 13b, a compressor 14, a heat exchanger (not shown), and a housing 13c that covers the blower 13b, the compressor 14, and the heat exchanger. The blower 13b blows air by being driven by the electric motor 13a. The blower 13b has, for example, blades 13d that are driven by the electric motor 13a. For example, the blades 13d are fixed to the shaft of the electric motor 13a and generate an airflow. The compressor 14 has an electric motor 14a (for example, the electric motor 1 according to the first embodiment), a compression mechanism 14b (for example, a refrigerant circuit) that is driven by the electric motor 14a, and a housing 14c that covers the electric motor 14a and the compression mechanism 14b.

[0088] In the air conditioner 10, at least one of the indoor unit 11 and the outdoor unit 13 has the motor 1 described in the first embodiment. That is, the indoor unit 11, the outdoor unit 13, or the indoor unit 11 and the outdoor unit 13 each have the motor 1 described in the first embodiment. Specifically, as a driving source for the blower section, the motor 1 described in the first embodiment is applied to at least one of the motors 11a and 13a. That is, the motor 1 described in the first embodiment is applied to the indoor unit 11, the outdoor unit 13, or the indoor unit 11 and the outdoor unit 13. The motor 1 described in the first embodiment may be applied to the motor 14a of the compressor 14.

[0089] The air conditioner 10 can perform air conditioning such as cooling operation to blow cold air from the indoor unit 11 and heating operation to blow warm air. In the indoor unit 11, the electric motor 11a is a drive source for driving the blower unit 11b. The blower unit 11b can blow conditioned air.

[0090] In the indoor unit 11, the electric motor 11a is fixed to a housing 11c of the indoor unit 11 by, for example, screws. In the outdoor unit 13, the electric motor 13a is fixed to a housing 13c of the outdoor unit 13 by, for example, screws.

[0091] In the air conditioner 10 according to the third embodiment, the electric motor 1 described in the first embodiment is applied to at least one of the electric motors 11a and 13a, and therefore it is possible to obtain the same advantages as those described in the first embodiment. As a result, it is possible to improve the efficiency of the air conditioner 10.

[0092] Furthermore, when the motor 1 according to the first embodiment is used as a drive source for a blower (e.g., indoor unit 11), the same advantages as those described in the first embodiment can be obtained. As a result, it is possible to prevent a decrease in efficiency of the blower. A blower having the motor 1 according to the first embodiment and a blade (e.g., blade 11d or 13d) driven by the motor 1 can be used alone as a device for blowing air. This blower can also be applied to devices other than the air conditioner 10.

[0093] Furthermore, when the electric motor 1 according to the first embodiment is used as the drive source of the compressor 14, the same advantages as those described in the first embodiment can be obtained. As a result, the efficiency of the compressor 14 can be improved.

[0094] The electric motor 1 explained in the first embodiment can be mounted in devices having a drive source, such as a ventilation fan, a home appliance, or a machine tool, in addition to the air conditioner 10.

[0095] The features of each embodiment and each modification described above can be combined with each other. [Explanation of symbols]

[0096] 1,11a,13a,14a,62 electric motor, 2 rotor, 3 stator, 21 main magnet, 31 stator core, 31a core back, 31b teeth, 32 coil, 33 insulator, 311 central teeth, 311a central teeth body, 311b,312b,313b upstream tip portion, 311c,312c,313c downstream tip portion, 312 upstream teeth, 312a upstream teeth body, 313 downstream teeth, 313a downstream teeth body, 331a,332a,333a upstream insulating portion, 331b,332b,333b downstream insulating portion.

Claims

1. A rotor having 10 magnetic poles; a stator having an annular core back and nine teeth extending from the annular core back toward the rotor; Equipped with The nine teeth are configured into three tooth groups, each group consisting of three teeth adjacent to each other in the circumferential direction, The three tooth groups correspond to a U phase, a V phase, and a W phase, respectively. the three teeth of each of the three tooth groups are composed of a central tooth located in the center of the three teeth, an upstream tooth located upstream of the central tooth in a rotational direction of the rotor, and a downstream tooth located downstream of the central tooth in the rotational direction, The upstream teeth are an upstream teeth body extending from the annular core back toward the rotor; an upstream tip portion facing the rotor and extending from the upstream teeth body toward the upstream side; a downstream tip portion that faces the rotor and extends from the upstream teeth body toward the downstream side; having In a plane perpendicular to the axial direction, when a length of the inner circumferential surface of the upstream tip portion of the upstream tooth along the inner circumferential surface of the upstream tip portion of the upstream tooth is defined as LFR and a length of the inner circumferential surface of the downstream tip portion of the upstream tooth along the inner circumferential surface of the downstream tip portion of the upstream tooth is defined as LFL, LFL>LFR Fulfilling The central teeth are a central teeth body extending from the annular core back toward the rotor; an upstream tip portion facing the rotor and extending from the central teeth body toward the upstream side; a downstream tip portion facing the rotor and extending from the central teeth body toward the downstream side; having The central tooth among the three teeth corresponding to the U-phase is defined as a U-phase central tooth, Among the nine teeth, the upstream tooth adjacent to the U-phase central tooth is defined as a U-phase upstream tooth, Among the nine teeth, the downstream tooth adjacent to the U-phase upstream tooth is defined as a V-phase downstream tooth; an angle formed by a line passing through a center of rotation of the rotor and an end portion on the upstream side of the upstream tip portion of the U-phase central tooth and a line passing through the center of rotation and an end portion on the downstream side of the downstream tip portion of the U-phase upstream tooth in the plane is defined as θ1f; When an angle formed by a line passing through the center of rotation and the upstream end of the upstream tip portion of the U-phase upstream tooth and a line passing through the center of rotation and the downstream end of the downstream tip portion of the V-phase downstream tooth on the plane is defined as θ2b, -18(deg)≦(θ1f-θ2b)<0(deg) Fulfilling the stator has an upstream insulator that insulates the upstream teeth, The upstream insulator includes: an upstream insulating portion adjacent to the upstream tip portion of the upstream tooth in the circumferential direction; a downstream insulating portion adjacent to the downstream tip portion of the upstream tooth in the circumferential direction; having a maximum thickness of the upstream insulating portion of the upstream insulator in the circumferential direction on the plane is defined as TFR; When a maximum thickness of the downstream insulating portion of the upstream insulator in the circumferential direction on the plane is TFL, TFL < TFR Meet the electric motor.

2. The downstream teeth are a downstream teeth body extending from the annular core back toward the rotor; an upstream tip portion facing the rotor and extending from the downstream teeth body toward the upstream side; a downstream tip portion that faces the rotor and extends from the downstream teeth body toward the downstream side; having In the plane, when a length of the inner circumferential surface of the upstream tip portion of the downstream tooth along the inner circumferential surface of the upstream tip portion of the downstream tooth is defined as LBR and a length of the inner circumferential surface of the downstream tip portion of the downstream tooth along the inner circumferential surface of the downstream tip portion of the downstream tooth is defined as LBL, LBL < LBR 2. The electric motor according to claim 1, which satisfies the above.

3. The central teeth are a central teeth body extending from the annular core back toward the rotor; an upstream tip portion facing the rotor and extending from the central teeth body toward the upstream side; a downstream tip portion facing the rotor and extending from the central teeth body toward the downstream side; having The central tooth among the three teeth corresponding to the U-phase is defined as a U-phase central tooth, The upstream tooth of the three teeth corresponding to the U-phase is defined as a U-phase upstream tooth, Among the nine teeth, the downstream tooth adjacent to the U-phase upstream tooth is defined as a V-phase downstream tooth; an angle formed by a line passing through a center of rotation of the rotor and an end portion on the upstream side of the upstream tip portion of the U-phase central tooth and a line passing through the center of rotation and an end portion on the downstream side of the downstream tip portion of the U-phase upstream tooth in the plane is defined as θ1f; When an angle formed by a line passing through the center of rotation and the upstream end of the upstream tip portion of the U-phase upstream tooth and a line passing through the center of rotation and the downstream end of the downstream tip portion of the V-phase downstream tooth on the plane is defined as θ2b, θ1f<θ2b 3. The electric motor according to claim 1 or 2, which satisfies the above.

4. The central teeth are a central teeth body extending from the annular core back toward the rotor; an upstream tip portion facing the rotor and extending from the central teeth body toward the upstream side; a downstream tip portion facing the rotor and extending from the central teeth body toward the downstream side; having The central tooth among the three teeth corresponding to the U-phase is defined as a U-phase central tooth, Among the nine teeth, the downstream tooth adjacent to the U-phase central tooth is defined as a U-phase downstream tooth, Among the nine teeth, the upstream tooth adjacent to the U-phase downstream tooth is defined as a W-phase upstream tooth; an angle formed by a line passing through a rotation center of the rotor and an upstream end of the upstream tip portion of the W-phase upstream tooth on the upstream side and a line passing through the rotation center and an downstream end of the downstream tip portion of the U-phase downstream tooth on the downstream side in the plane is defined as θ3f; When an angle formed by a line passing through the center of rotation and the downstream end of the downstream tip portion of the U-phase central tooth and a line passing through the center of rotation and the upstream end of the upstream tip portion of the U-phase downstream tooth on the plane is defined as θ1b, θ3f>θ1b The electric motor according to any one of claims 1 to 3, which satisfies the above.

5. -16(deg)≦(θ1f-θ2b)≦-5(deg) 2. The electric motor according to claim 1, which satisfies the above.

6. the stator has a downstream insulator that insulates the downstream teeth, The downstream insulator includes: an upstream insulating portion adjacent to the upstream tip portion of the downstream tooth in the circumferential direction; a downstream insulating portion adjacent to the downstream tip portion of the downstream tooth in the circumferential direction; having a maximum thickness of the upstream insulating portion of the downstream insulator in the circumferential direction on the plane is defined as TBR; When a maximum thickness of the downstream insulating portion of the downstream insulator in the circumferential direction on the plane is TBL, TBL>TBR The electric motor according to any one of claims 1 to 5, which satisfies the above.

7. Feathers and The electric motor according to any one of claims 1 to 6 for driving the blades; Equipped with a fan.

8. An indoor unit; an outdoor unit connected to the indoor unit; Equipped with The indoor unit, the outdoor unit, or both the indoor unit and the outdoor unit each have the electric motor according to any one of claims 1 to 6. Air conditioner.

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