Stator structure and synchronous motor

Abstract

To provide a stator structure and a synchronous motor, which reduce loss due to influence of magnetic flux distribution of each part of a stator and can improve efficiency.SOLUTION: A stator structure is arranged around a rotor 200 and includes an annular magnetic path part 110 and a plurality of projection magnetic pole parts 120 projecting toward a radial inner side from the annular magnetic path part 110 at prescribed angle intervals. A first flange part 130F extending forward in a rotation direction R of the rotor 200 and a second flange part 130R extending backward in the rotation direction R of the rotor 200 are formed at respective tips of the plurality of projection magnetic pole parts 120. First length L1 from the projection magnetic pole parts 120 to an end in a front side in the rotation direction R of the first flange part 130F and second length L2 from the projection magnetic pole parts 120 to an end in a back side in the rotation direction R of the second flange part 130R satisfy a relation of L1<L2 .SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a stator structure and a synchronous motor, and more particularly to a stator structure and a synchronous motor in which loss due to magnetic flux distribution in the stator is taken into consideration. [Background technology]

[0002] In a synchronous motor, a stator with stator coils (hereinafter referred to as "coils") wound around protruding magnetic poles is located around a rotor with embedded permanent magnets. Patent Document 1 describes an attempt to improve efficiency in this type of embedded permanent magnet synchronous motor by adjusting the shape of the flanges at the tips of the protruding magnetic poles of the stator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-27369 Summary of the Invention [Problem to be solved by the invention]

[0004] 14, the technology disclosed in Patent Document 1 has a stator 100 arranged around a rotor 200, which has a plurality of protruding magnetic pole portions 120 that protrude radially inward from an annular magnetic path portion 110 at predetermined angular intervals, and a first flange portion 130F that extends forward in the rotation direction R of the rotor 200 is provided at the tip of each protruding magnetic pole portion 120, and the flange portion on the rear side in the rotation direction R of the rotor 200 is cut off. This attempts to improve iron loss in the stator.

[0005] Considering the influence of magnetic flux distribution in each part of the stator of a synchronous motor and judging the various types of loss comprehensively, it was found that the conventional configuration shown in Fig. 14 was unable to reduce losses comprehensively and that it was difficult to improve efficiency.

[0006] The present invention has been made to solve the above problems, and an object thereof is to provide a stator structure and a synchronous motor capable of reducing losses due to the influence of the magnetic flux distribution of each part of the stator and increasing efficiency.

Means for Solving the Problems

[0007] The stator structure according to this invention is arranged around a rotor and has an annular magnetic path portion and a plurality of protruding magnetic pole portions protruding from the annular magnetic path portion at predetermined angular intervals toward the radially inner side. At the tip of each of the plurality of protruding magnetic pole portions, a first bar portion extending forward in the rotation direction of the rotor and a second bar portion extending rearward in the rotation direction of the rotor are formed. The first length L1 from the protruding magnetic pole portion to the front end of the first bar portion on the forward side in the rotation direction and the second length L2 from the protruding magnetic pole portion to the rear end of the second bar portion on the rearward side in the rotation direction are configured to satisfy the relationship L1 < L2.

[0008] In the stator structure according to this invention, the first length L1 of the first bar portion and the second length L2 of the second bar portion may be configured to satisfy the relationship 0.45 ≦ (L1 / L2) ≦ 0.95.

[0009] The protruding magnetic pole portion of the stator structure according to this invention may be configured such that a coil is wound as a concentrated winding.

[0010] In the stator structure according to this invention, among the plurality of protruding magnetic pole portions, in adjacent protruding magnetic pole portions, a magnetic wedge formed of a magnetic powder molded body may be provided between the first bar portion and the second bar portion facing each other in the circumferential direction.

[0011] In the stator structure according to this invention, the magnetic wedge may be formed of a magnetic powder molded body having a lower magnetic permeability than the magnetic material constituting the annular magnetic path portion and the protruding magnetic pole portion.

[0012] In the stator structure according to this invention, the coil may be wound around the protruding magnetic pole portion so as to maintain a certain distance from the first bar portion.

[0013] The permanent magnet embedded type synchronous motor according to this invention has a rotor in which permanent magnets are embedded to alternately generate N poles and S poles in the circumferential direction on the surface, and a stator disposed around the rotor. The stator is disposed around the rotor and has an annular magnetic path portion and a plurality of protruding magnetic pole portions protruding from the annular magnetic path portion radially inward at predetermined angular intervals. At the tip of each of the plurality of protruding magnetic pole portions, a first tooth portion extending forward in the rotation direction of the rotor and a second tooth portion extending backward in the rotation direction of the rotor are formed. The first length L1 from the protruding magnetic pole portion to the front end in the rotation direction of the first tooth portion and the second length L2 from the protruding magnetic pole portion to the rear end in the rotation direction of the second tooth portion are configured to satisfy the relationship L1 < L2.

Effect of the Invention

[0014] In the stator structure and the synchronous motor according to this invention, in a stator having a plurality of protruding magnetic pole portions protruding from the annular magnetic path portion radially inward at predetermined angular intervals, at the tip of each of the plurality of protruding magnetic pole portions, a first tooth portion extending forward in the rotation direction of the rotor and a second tooth portion extending backward in the rotation direction of the rotor are formed. The first length L1 of the first tooth portion and the second length L2 of the second tooth portion are configured to satisfy the relationship L1 < L2. With this configuration, by shortening a part of the first tooth portion, which is a portion where the iron loss density is relatively high in the stator, the iron loss of the stator at this portion is reduced. Furthermore, by shortening a part of the first tooth portion, the magnetic flux linked with the coil is reduced. Thereby, the iron loss in the stator and the eddy current loss in the coil can be reduced, and it becomes possible to reduce the loss due to the influence of the magnetic flux distribution of each part of the stator of the synchronous motor and improve the efficiency.

Brief Description of the Drawings

[0015] [Figure 1] It is a configuration diagram showing the structure of the rotor and the structure of the stator in the permanent magnet embedded type synchronous motor according to Embodiment 1. [Figure 2] It is a configuration diagram showing in detail the structure of the stator according to Embodiment 1. [Figure 3]4 is an explanatory diagram showing a magnetic flux distribution in the stator according to the first embodiment in comparison with a magnetic flux distribution in a comparative example. FIG. [Figure 4] FIG. 3 is an explanatory diagram showing the loss occurring in the first embodiment in comparison with the loss occurring in a comparative example. [Figure 5] 5 is a characteristic diagram showing loss characteristics that change depending on the ratio between the first length of the first flange and the second length of the second flange of the stator according to the first embodiment. FIG. [Figure 6] FIG. 10 is a configuration diagram showing in detail the structure of a stator according to a second embodiment. [Figure 7] FIG. 10 is a characteristic diagram showing DC magnetization characteristics of members used in the stator according to the second embodiment. [Figure 8] FIG. 10 is a characteristic diagram showing iron loss characteristics of members used in the stator according to the second embodiment. [Figure 9] 10 is a configuration diagram showing in detail the structure of a specific configuration example of a stator according to a second embodiment. FIG. [Figure 10] 10 is an explanatory diagram showing the magnetic flux distribution in the stator of the second embodiment in comparison with the magnetic flux distribution in the stator of the first embodiment. FIG. [Figure 11] 10 is an explanatory diagram showing the loss occurring in the second embodiment in comparison with the loss occurring in a comparative example and the first embodiment. FIG. [Figure 12] FIG. 10 is a configuration diagram showing the structure of a stator according to a third embodiment. [Figure 13] 10 is an explanatory diagram showing the magnetic flux distribution in the stator of the third embodiment in comparison with the magnetic flux distribution in the stator of the second embodiment. FIG. [Figure 14] FIG. 10 is a diagram showing the structure of a conventional stator. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of a stator structure (hereinafter referred to as "stator structure") and a synchronous motor according to the present invention will be described with reference to the drawings. In each drawing, the same parts are designated by the same reference numerals.

[0017] Embodiment 1 First, the structure of a stator 100 in the first embodiment will be described with reference to FIGS. Fig. 1 is a configuration diagram showing the structure of a stator 100 and the structure of a rotor 200 in an embedded permanent magnet synchronous motor 1 according to embodiment 1. Fig. 2 is a configuration diagram showing the structure of the stator 100 according to embodiment 1 in detail. The synchronous motor 1 mainly has a stator 100 arranged around the rotor 200, and the rotor 200 rotating inside the stator 100. In the following description, the direction along the radius of the stator 100 and the rotor 200 is referred to as the "radial direction," the direction along the rotation direction of the rotor 200 is referred to as the "circumferential direction," and the direction along the axis of the rotor 200 is referred to as the "axial direction."

[0018] [Structure of stator 100] The stator 100 mainly has an annular magnetic path portion 110 and a protruding magnetic pole portion 120. The annular magnetic path portion 110 is formed in an annular shape on the outer periphery of the stator 100. The protruding magnetic pole portion 120 is formed so that multiple magnetic poles protrude radially inward from the annular magnetic path portion 110 at predetermined angular intervals. Slots 140 are formed between the multiple protruding magnetic pole portions 120. The slots 140 are used as spaces to accommodate coils 150 wound around the protruding magnetic pole portions 120. The coils 150 are wound around each of the protruding magnetic pole portions 120 in a concentrated winding manner. At the tip of each of the plurality of protruding magnetic pole portions 120, a first flange portion 130F extending forward in the rotation direction R of the rotor 200 and a second flange portion 130R extending rearward in the rotation direction R of the rotor 200 are formed.

[0019] [Structure of rotor 200] The rotor 200 shall rotate in the R direction shown in FIG. 1. A plurality of permanent magnets 210 and 220 are alternately embedded in the rotor 200 at predetermined angular intervals. The permanent magnet 210 has a shape with the circumferential direction as the longitudinal direction and is magnetized in the radial direction. The permanent magnet 220 has a shape with the radial direction as the longitudinal direction and is magnetized in the circumferential direction. The plurality of permanent magnets 210 and 220 generate N poles and S poles alternately in the circumferential direction on the surface of the rotor 200. Here, an example of the arrangement of the plurality of permanent magnets 210 and 220 is shown, and various modifications are possible.

[0020] [Detailed Structure of the Stator 100] In FIG. 2, let the circumferential width of the protruding magnetic pole portion 120 be L0, the first length in the circumferential direction from the protruding magnetic pole portion 120 to the end on the front side in the rotation direction R of the first rib portion 130F be L1, and the second length in the circumferential direction from the protruding magnetic pole portion 120 to the end on the rear side in the rotation direction R of the second rib portion 130R be L2. In such a stator 100, L1 and L2 are configured to satisfy the relationship L1 < L2. Here, for a conventionally existing general stator (hereinafter referred to as "conventional standard type stator"), let the length of the rib portion equal on the front side and the rear side in the rotor rotation direction R be Lorg. In this case, it is desirable to configure it to satisfy the relationship Lorg ≒ L2 > L1. That is, while making the second length L2 of the second rib portion 130R equivalent to that of the conventional standard type stator, it is desirable to configure the first length L1 of the first rib portion 130F to be shorter than that of the conventional standard type stator.

[0021] [Magnetic Flux Distribution] Hereinafter, the magnetic flux distribution in the stator 100 of Embodiment 1 will be described by comparing it with a comparative example with reference to FIG. 3. FIG. 3 is an explanatory diagram showing the magnetic flux distribution in the stator 100 of Embodiment 1 in comparison with the magnetic flux distribution in the comparative example. Fig. 3(a) shows the magnetic flux distribution in a comparative example. Here, the comparative example is assumed to be a conventional standard stator having the same length of the flange portion on the front side and rear side of the rotor rotation direction R. Fig. 3(b) shows the magnetic flux distribution in stator 100 of embodiment 1. In the first embodiment, the first length L1 of the first flange 130F is shorter than the second length L2 of the second flange 130R, thereby reducing the magnetic flux passing through the first flange 130F. As a result, the magnetic flux is reduced in the region (b1) in FIG. 3(b) compared to the region (a1) in FIG. 3(a). On the other hand, due to the decrease in magnetic flux passing through the first flange 130F, the magnetic flux passing through the second flange 130R, which is positioned opposite the first flange 130F, increases. As a result, the magnetic flux in the region (b2) in Fig. 3(b) is increased compared to the region (a2) in Fig. 3(a). As a result of the above-described change in magnetic flux, the interlinking magnetic flux decreases near region (b3) of coil 150 in (b) of Figure 3, and the area of ​​the range where eddy current loss is high decreases compared to region (a3) ​​in (a) of Figure 3. This reduction in the area of ​​the range where eddy current loss is high reduces AC copper loss in coil 150 compared to conventional cases.

[0022] [loss] The improvement in loss in stator 100 according to the first embodiment will be described below with reference to Fig. 4. Fig. 4 is an explanatory diagram showing the loss occurring in the first embodiment in comparison with the loss occurring in a comparative example. Here, (a) of Figure 4 shows the losses in a prior art synchronous motor (see Figure 14) proposed in JP 2005-27369 A, in which the flange portion at the tip of the protruding magnetic pole portion of the stator 100 is extended on the front side in the rotation direction R of the rotor 200 and cut off on the rear side in the rotation direction R. FIG. 4(b) shows the loss in a synchronous motor of a comparative example having a conventional standard stator with flanges having equal lengths on the front and rear sides in the rotor rotation direction R. FIG. 4(c) shows losses in the synchronous motor 1 having the stator 100 of the first embodiment in which the first length L1 of the first flange portion 130F is shorter than the first length L2 of the second flange portion 130R. In order to accurately verify the results of the experiment, three types of synchronous motors were prepared with the same values ​​except for the length of the rib, and the various types of loss in each synchronous motor were calculated. The five types of loss calculated were DC copper loss, stator loss, rotor magnet eddy current loss, rotor loss, and AC copper loss.

[0023] Rotor loss and rotor magnet eddy current loss In the first embodiment, the rotor loss corresponding to the iron loss of the rotor 200 and the eddy current loss of the permanent magnets 210, 220 were worse than those in the comparative example. This deterioration is thought to be due to an increase in slot harmonics caused by the shortening of the first length L1 of the first flange portion 130F, which widened the opening of the slot 140 and increased the distortion of the magnetic flux. Stator loss and AC copper loss On the other hand, in the first embodiment, the stator loss corresponding to the iron loss of the stator 100 is improved, and the AC copper loss corresponding to the eddy current loss of the coil 150 is also significantly improved. The reduction in the iron loss of the stator 100 is believed to be caused by shortening the first length L1 of the first flange portion 130F. The reduction in the AC copper loss is believed to be caused by a reduction in the magnetic flux linking the coil 150. Total loss As a result of the above, the total loss in the first embodiment was 1277 W, which was sufficiently smaller than the total loss of 1283 W in the comparative example, and good results were obtained due to the effect of the improvement in AC copper loss. On the other hand, according to the prior art, the rotor magnet eddy current loss, rotor loss, and AC copper loss were worse than those of the comparative example.

[0024] The maximum torque of the synchronous motor was 321.1 Nm in the prior art, 331.6 Nm in the comparative example, and 333.9 N·m in the first embodiment, with the first embodiment providing favorable results.

[0025] [Ratio of first length L1 and second length L2, and relationship with loss] Hereinafter, referring to FIG. 5, losses that change according to the ratio of the first length L1 of the first end portion 130F and the second length L2 of the second end portion 130R will be described. FIG. 5 is a characteristic diagram showing the characteristics of losses that change according to the ratio of the first length L1 of the first end portion 130F and the second length L2 of the second end portion 130R of the stator 100 according to Embodiment 1. In FIG. 5, the horizontal axis represents L1 / L2, and the vertical axis represents the total loss. The horizontal axis value of 1.0 corresponds to a comparative example having a conventional standard type stator where L1 = L2. The region where the horizontal axis is greater than 1.0 corresponds to the prior art proposed in Japanese Patent Application Laid-Open No. 2005-27369 where L1 > L2. The region where the horizontal axis is less than 1.0 corresponds to Embodiment 1 where L1 < L2. Here, a region where 0.45 ≤ (L1 / L2) ≤ 0.95 and the loss is smaller than the total loss of 1283 W at L1 / L2 = 1 is considered to be a range in which an effective loss reduction effect can be obtained in Embodiment 1. Even when the sizes of other parts other than L1 and L2 are changed, the characteristics of FIG. 5 are satisfied. Therefore, by configuring the first length L1 of the first end portion 130F and the second length L2 of the second end portion 130R to satisfy the condition of 0.45 ≤ (L1 / L2) ≤ 0.95, the total loss can be kept small.

[0026] [Effects Obtained by Embodiment 1] The stator 100 according to Embodiment 1 is arranged around the rotor 200 and has an annular magnetic path portion 110 and a plurality of protruding magnetic pole portions 120 that protrude from the annular magnetic path portion 110 at predetermined angular intervals toward the radially inner side. At the tip of each of the plurality of protruding magnetic pole portions 120, a first end portion 130F extending forward in the rotation direction R of the rotor 200 and a second end portion 130R extending rearward in the rotation direction R of the rotor 200 are formed. Here, the first length L1 from the protruding magnetic pole portion 1 to the front end portion of the first end portion 130F in the rotation direction R and the second length L2 from the protruding magnetic pole portion 120 to the rear end portion of the second end portion 130R in the rotation direction R are configured to satisfy the relationship L1 < L2. In this way, shortening a portion of the first flange 130F, which is a portion of the stator 100 where the iron loss density is relatively high, reduces the iron loss of the stator 100 at this portion. Furthermore, shortening a portion of the first flange 130F reduces the magnetic flux linkage with the coil 150. This reduces the iron loss in the stator 100 and the eddy current loss in the coil 150. The permanent magnet embedded synchronous motor 1, which has the above-described stator 100 and a rotor 200 in which permanent magnets are embedded and which generates alternating north and south poles in the circumferential direction on the surface, can reduce losses due to the influence of magnetic flux distribution in each part of the stator 100 and increase the efficiency of the synchronous motor 1.

[0027] In the structure of the stator 100 according to embodiment 1, by configuring the first length L1 of the first flange portion 130F and the second length L2 of the second flange portion 130R to satisfy the relationship 0.45≦(L1 / L2)≦0.95, it is possible to keep the overall loss small compared to the comparative example having a conventional standard stator in which L1=L2.

[0028] In the structure of stator 100 according to the first embodiment, coil 150 is wound as concentrated winding around protruding magnetic pole portion 120. Therefore, magnetic flux linking with coil 150 is susceptible to eddy current loss, and reducing the magnetic flux linking with coil 150 can improve eddy current loss.

[0029] Embodiment 2 The structure of stator 100 in embodiment 2 will be described with reference to Fig. 6. Fig. 6 is a configuration diagram showing the structure of stator 100 according to embodiment 2 in detail. In Fig. 6, the same components as those described in embodiment 1 are given the same reference numerals, and redundant description will be omitted, with the description focusing on the different parts.

[0030] [Structure of stator 100] In adjacent protruding magnetic pole portions 120 among the plurality of protruding magnetic pole portions 120, a magnetic wedge 160 made of a magnetic powder molded body is further provided between the first flange portion 130F and the second flange portion 130R that face each other in the circumferential direction so as to cover the opening of the slot 140. The magnetic wedge 160 prevents the coil 150 from falling out of the slot 140 and controls the magnetic flux that links with the coil 150.

[0031] [Magnetic Wedge 160 Characteristics] The characteristics of the magnetic powder molded body used in the magnetic wedge 160 will be explained with reference to FIGS. 7 is a characteristic diagram showing the DC magnetization characteristics of members used in stator 100 according to embodiment 2. In FIG. 7, the horizontal axis represents the magnetic field H, and the vertical axis represents the magnetic flux density B. Fig. 8 is a characteristic diagram showing the iron loss characteristics of the members used in stator 100 according to embodiment 2. In Fig. 8, the horizontal axis represents magnetic flux density B, and the vertical axis represents iron loss density P. The iron loss characteristics of the magnetic powder molded body in Fig. 8 are those at a frequency of 1 kHz, and are shown by the actual measured values ​​indicated by the solid line and the estimated approximate values ​​indicated by the dashed line. Here, the characteristics of the magnetic steel sheets constituting the annular magnetic path portion 110, the protruding magnetic pole portion 120, and the first and second flange portions 130F and 130R, and the magnetic powder compact constituting the magnetic wedge 160, as components used in the stator 100, will be described. A non-oriented magnetic steel strip 35H300 (product name) is used as a specific example of the magnetic steel sheets. Sendust (registered trademark), an alloy made of iron, silicon, and aluminum, is used as a specific example of the magnetic powder compact. Note that the characteristics of specific examples are shown here, and other magnetic steel sheets and magnetic powder compacts can also be used in the second embodiment. As shown in the DC magnetization curve of Figure 7, the magnetic powder molded body that constitutes the magnetic wedge 160 has a smaller magnetic permeability than the electromagnetic steel sheets that constitute the annular magnetic path portion 110, the protruding magnetic pole portion 120, and the first flange portion 130F and the second flange portion 130R. As shown in the iron loss characteristics of FIG. 8, the magnetic powder compact that constitutes the magnetic wedge 160 has iron loss characteristics that are lower than those of an electromagnetic steel sheet.

[0032] [Specific Configuration Example of Stator 100] The size of each part of a specific configuration example used to measure the magnetic flux distribution and loss of stator 100 according to the second embodiment will be described with reference to Fig. 9. Fig. 9 is a configuration diagram showing in detail the structure of a specific configuration example of stator 100 according to the second embodiment. Here, the stator 100 is configured such that the circumferential width L0 of the protruding magnetic pole portion 120 is 12 mm, the first length L1 of the first flange portion 130F is 1.0 mm, the second length L2 of the second flange portion 130R is 2.0 mm, the circumferential length M1 of the magnetic wedge 160 is 4.62 mm, the radial thickness M2 of the magnetic wedge 160 is 0.76 mm, and the axial length of the magnetic wedge 160 (perpendicular to the paper surface of Figure 9) is 84.5 mm.

[0033] [Magnetic flux distribution] The magnetic flux distribution in the stator 100 of the second embodiment will be described below in comparison with that in the first embodiment with reference to Fig. 10. Fig. 10 is an explanatory diagram showing the magnetic flux distribution in the stator 100 of the second embodiment in comparison with the magnetic flux distribution in the stator 100 of the first embodiment. 10(a) shows the magnetic flux distribution in the stator 100 of the first embodiment. FIG. 10(b) shows the magnetic flux distribution in the stator 100 of the second embodiment having the magnetic wedge 160. In the second embodiment shown in Fig. 10(b), a magnetic wedge 160 is provided at the opening of the slot 140. Therefore, it can be seen that the magnetic flux from the rotor 200 at the opening of the slot 140 is increased in the second embodiment shown in Fig. 10(b) compared to the first embodiment shown in Fig. 10(a).

[0034] [loss] The improvement in loss in stator 100 according to the second embodiment will be described below with reference to Fig. 11. Fig. 11 is an explanatory diagram showing the loss occurring in the second embodiment in comparison with the loss occurring in a comparative example and the first embodiment. Here, Fig. 11(a) shows the loss in a comparative synchronous motor having a conventional standard stator with a flange having equal lengths on the front and rear sides in the rotor rotation direction R. The loss in the comparative synchronous motor shown in Fig. 11(a) is the same as that shown in Fig. 4(b). Fig. 11(b) shows losses in the synchronous motor 1 having the stator 100 of the first embodiment in which the first length L1 of the first flange portion 130F is shorter than the first length L2 of the second flange portion 130R. The losses in the synchronous motor of the first embodiment shown in Fig. 11(b) are the same as those shown in Fig. 4(c).

[0035] (c) of Figure 11 shows losses in a synchronous motor 1 having a stator 100 of embodiment 2, in which the first length L1 of the first flange portion 130F is shorter than the first length L2 of the second flange portion 130R and a magnetic wedge 160 is provided between the opposing first flange portion 130F and second flange portion 130R. In order to properly verify the results of the experiment, three types of synchronous motors were prepared with the same values ​​except for the length of the flange and whether or not the magnetic wedge 160 was included, and the various types of loss in each synchronous motor were calculated. The five types of loss calculated were DC copper loss, stator loss, rotor magnet eddy current loss, rotor loss, and AC copper loss, plus the loss in the magnetic powder compact of the magnetic wedge 160.

[0036] Below, the comparative example (FIG. 11(a)), the first embodiment (FIG. 11(b)), and the second embodiment (FIG. 11(c)) will be compared and examined in terms of loss. ·AC copper loss Regarding AC copper loss, in the first embodiment, the magnetic flux linking with coil 150 is reduced due to a change in the magnetic path caused by shortening first length L1 of first flange portion 130F, and AC copper loss is improved to 164 W compared to 191 W in the comparative example. In the second embodiment, magnetic wedge 160 is provided at the opening of slot 140, which induces magnetic flux at the opening of slot 140. The induced magnetic flux links with coil 150, and AC copper loss increases slightly to 182 W compared to 164 W in the first embodiment. However, the AC copper loss of 182 W in the second embodiment is improved compared to the AC copper loss of 191 W in the comparative example.

[0037] Rotor loss In the first embodiment, the rotor loss was significantly worsened to 92.0 W compared to 69.5 W in the comparative example, due to the shortened first length L1 of the first flange portion 130F. However, in the second embodiment, the slot harmonics can be suppressed by applying the magnetic wedge 160, and therefore the rotor loss is greatly improved to 48.8 W compared to 69.5 W in the comparative example. Rotor magnet eddy current loss In the first embodiment, the rotor magnet eddy current loss was worsened to 103 W compared to 90.1 W in the comparative example by shortening the first length L1 of the first flange portion 130F. However, in the second embodiment, slot harmonics can be suppressed by applying the magnetic wedge 160, and therefore the power output is greatly improved to 88.3 W compared to 90.1 W in the comparative example.

[0038] Stator loss In the first embodiment, the stator loss is improved to 470 W compared to 485 W in the comparative example by shortening the first length L1 of the first flange portion 130F. In the second embodiment, in addition to shortening the first length L1 of the first flange portion 130F, magnetic induction to the slot 140 is performed by the magnetic wedge 160, so the stator loss is improved to 467 W compared to 470 in the first embodiment. Loss of magnetic powder compacts In the second embodiment, the loss of 0.46 W due to the magnetic powder molded body that constitutes the magnetic wedge 160 is added. Total loss As a result of the above, the total loss in the second embodiment was 1234 W, which was a significant improvement over the total loss of 1283 W in the comparative example and the total loss of 1277 W in the first embodiment, and a favorable result was obtained.

[0039] [Effects obtained by the second embodiment] In the structure of the stator 100 according to the second embodiment, adjacent ones of the plurality of protruding magnetic pole portions 120 are provided with magnetic wedges 160 made of a magnetic powder molded body between the first flange portion 130F and the second flange portion 130R that face each other in the circumferential direction, and the magnetic wedges 160 perform magnetic induction to the slots 140, thereby further reducing various types of losses. As a result, losses due to the influence of the magnetic flux distribution in each portion of the stator 100 can be reduced, and the efficiency of the synchronous motor 1 can be improved.

[0040] In the structure of the stator 100 according to the second embodiment, the magnetic wedge 160 is made of a magnetic powder molded body having a magnetic permeability lower than that of the magnetic material constituting the annular magnetic path portion 110 and the protruding magnetic pole portion 120. Therefore, the magnetic wedge 160 appropriately guides the magnetic field into the slot 140, thereby further reducing various losses.

[0041] Embodiment 3 The structure of the stator 100 in the third embodiment will be described with reference to Fig. 12. Fig. 12 is a configuration diagram showing the structure of the stator 100 according to the third embodiment. In Fig. 12, the same components as those described in the first and second embodiments are given the same reference numerals, and the description will focus on the different parts, without repeating the same description.

[0042] [Structure of stator 100] The coil 150 wound around the protruding magnetic pole portion 120 uses a flat wire having a cross section that is nearly rectangular in order to effectively utilize the space of the slot 140. Of the flat wires forming the coil 150, two flat wires 150x1 and 150x2 that are close to the first flange portion 130F are configured to have an even thinner flat cross section than the others. As a result, the coil 150 is wound around the protruding magnetic pole portion 120 so as to maintain a certain distance from the first flange portion 130F, resulting in an area 151 where the coil 150 is not present near the first flange portion 130F. On the other hand, the coil 150 is present close to the second flange portion 130R, as in the conventional case. Although the two rectangular wires 150x1 and 150x2 adjacent to the first flange portion 130F are configured to have a thinner flat cross section than the others, one or three rectangular wires may be configured to have a thinner flat cross section than the others.

[0043] [Magnetic flux distribution] The magnetic flux distribution in the stator 100 of the third embodiment will be described below in comparison with that in the second embodiment with reference to Fig. 13. Fig. 13 is an explanatory diagram showing the magnetic flux distribution in the stator 100 of the third embodiment in comparison with the magnetic flux distribution in the stator 100 of the second embodiment. Fig. 13(a) shows the magnetic flux distribution in the stator 100 of the second embodiment. Fig. 13(b) shows the magnetic flux distribution in the stator 100 of the third embodiment. In (a) of Figure 13, attention is focused on the magnetic flux φ1 that links with the coil 150 closest to the first flange portion 130F. In (b) of Figure 13, the magnetic flux φ1 at the same position as in (a) of Figure 13 passes through an area 151 (see Figure 12) where the coil 150 does not exist, and therefore does not link with the coil 150. With the configuration and magnetic flux distribution of the third embodiment, although DC copper loss increases slightly as the cross-sectional area of ​​the coil 150 decreases, AC copper loss decreases due to the reduction in magnetic flux linking with the coil 150, and therefore it is possible to further reduce the total loss.

[0044] [Effects obtained by the third embodiment] In the structure of the stator 100 according to the third embodiment, of the rectangular wire forming the coil 150, the coil close to the first flange portion 130F extending forward in the rotation direction R of the rotor 200 is configured to have a thinner flat cross section than the other coils. That is, the coil 150 is wound around the protruding magnetic pole portion 120 so as to maintain a certain distance from the first flange portion 130F, and therefore a region 151 where the coil 150 is not present is generated while being close to the first flange portion 130F. As a result, AC copper loss is reduced due to a reduction in magnetic flux interlinking with the coil 150, making it possible to further reduce the total loss. [Explanation of symbols]

[0045] 1 synchronous motor, 100 stator, 110 annular magnetic path portion, 120 protruding magnetic pole portion, 130F first flange portion, 130R second flange portion, 140 slot, 150 coil, 150x1, 150x2 flat wire, 151 area where no coil is present, 160 magnetic wedge, 200 rotor, 210, 220 permanent magnet, L0 circumferential width of protruding magnetic pole portion, L1 first length of first flange portion, L2 second length of second flange portion, M1 circumferential length of magnetic wedge, M2 radial thickness of magnetic wedge, R direction of rotor rotation, φ1 magnetic flux near the first flange portion.

Claims

1. The rotor (200) is disposed around the rotor (200), and has an annular magnetic path portion (110) and a plurality of protruding magnetic pole portions (120) protruding radially inward from the annular magnetic path portion (110) at predetermined angular intervals, a first flange portion (130F) extending forward in the rotation direction (R) of the rotor (200) and a second flange portion (130R) extending backward in the rotation direction (R) of the rotor (200) are formed at the tip of each of the plurality of protruding magnetic pole portions (120); a first length L1 from the protruding magnetic pole portion (120) to a front end of the first flange portion (130F) in the rotation direction (R) and a second length L2 from the protruding magnetic pole portion (120) to a rear end of the second flange portion (130R) in the rotation direction (R) are configured to satisfy the relationship L1<L2. Stator structure.

2. The first length L1 of the first flange portion (130F) and the second length L2 of the second flange portion (130R) are such that 0.45≦(L1 / L2)≦0.95 are configured to satisfy the relationship The stator structure according to claim 1 .

3. A coil (150) is wound around the protruding magnetic pole portion (120) in concentrated winding. The stator structure according to claim 1 .

4. In adjacent protruding magnetic pole portions (120) among the plurality of protruding magnetic pole portions (120), a magnetic wedge (160) formed of a magnetic powder molded body is provided between the first flange portion (130F) and the second flange portion (130R) that face each other in the circumferential direction. The stator structure according to claim 1 .

5. the magnetic wedge (160) is formed of the magnetic powder molded body having a magnetic permeability lower than that of the magnetic material forming the annular magnetic path portion (110) and the protruding magnetic pole portion (120). The stator structure according to claim 4 .

6. The coil (150) is wound around the protruding magnetic pole portion (120) so as to maintain a constant distance from the first flange portion (130F). The stator structure according to claim 1 .

7. the rotor (200) having permanent magnets embedded therein to generate alternating north and south poles in the circumferential direction of the surface; a stator (100) according to any one of claims 1 to 6, which is disposed around the rotor (200); A permanent magnet embedded synchronous motor having the above structure.

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