Rotating electric machine

Abstract

The invention provides a rotating electrical machine. The purpose of the present invention is to reduce noise generated by vibration accompanying driving of a rotating electrical machine. A rotating electrical machine (10) is provided with a rotor (19) having a magnetic body (30) and a shaft member that rotates integrally with the magnetic body, and a stator (60) having a stator core (61) and a coil (62). The stator core has a cylindrical yoke body (71) extending in the axial direction (X), and teeth (72) located inside the yoke body and extending from the yoke body. When La / 2 is the dimension from the center point (P) to a first intersection point (P1) between the orthogonal axis (L2) and the outer peripheral surface (71a) of the yoke body, Lb / 2 is the dimension from the center point to a second intersection point (P2) between the orthogonal axis and the end surface (76) of the tooth, Lc is the thickness of the yoke body on the orthogonal axis, and Ld is the length of the tooth on the orthogonal axis, La / 2-Lb / 2 = Lc + Ld, 0.15 < = Lb / La < = 0.35, and Lc / Ld > = 0.35.

Description

Technical Field

[0001] The present invention relates to rotating electrical machines. Background Art

[0002] The rotating electric machine described in Patent Document 1 comprises a rotor and a stator. The rotor comprises a magnetic body and an axial member rotating integrally with the magnetic body. The stator comprises a stator core and a coil. As a stator core, a stator core comprising a yoke body and teeth is known. The yoke body extends along the axial direction of the axial member and is in a cylindrical shape centered on the axis of the axial member. When a line extending along an orthogonal direction orthogonal to the axis of the axial member is set as an orthogonal axis, the teeth are located inside the yoke body and extend from the yoke body along the orthogonal axis. The coil is wound around the teeth.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2002-209354 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the case of a rotating electric machine in which the shaft member rotates at high speed, in order to suppress the loss of the rotor, the size of the shaft member in the orthogonal direction is sometimes reduced. In this case, in order to ensure the size of the gap between the shaft member and the end face of the tooth in the orthogonal direction with an appropriate value, it is necessary to reduce the size from the center point of the point on the orthogonal axis as the center of the yoke to the intersection of the orthogonal axis and the end face of the tooth in accordance with the size of the above-mentioned shaft member. In addition, since it is necessary to ensure the area occupied by the coil inside the yoke, there is a limit in reducing the size from the center point to the intersection of the orthogonal axis and the outer peripheral surface of the yoke. As a result, the ratio of the size from the center point to the intersection of the orthogonal axis and the end face of the tooth to the size from the center point to the intersection of the orthogonal axis and the outer peripheral surface of the yoke becomes a value within a specific range. In this way, in a rotating electric machine in which the above-mentioned ratio becomes a value within a specific range, the longer the length of the tooth, the smaller the thickness of the yoke. However, according to the length of the tooth and the thickness of the yoke, since the natural vibration frequency in the rotating electric machine becomes smaller, the natural vibration frequency may become a value within the range of the operating frequency. When the natural frequency is within the range of the operating frequency, resonance may occur with the driving of the rotating electrical machine, and noise due to vibration may be generated. Therefore, it is desirable to reduce such noise due to vibration in the rotating electrical machine.

[0008] In addition, when the coil is wound around the teeth by distributed winding, the electromagnetic force that serves as the basis of the exciting force acting on the teeth is distributed to each tooth. In contrast, when the coil is wound around the teeth by concentrated winding, the electromagnetic force is not distributed to each tooth as in the case where the coil is wound around the teeth by distributed winding, and therefore a large electromagnetic force acts on the teeth. Therefore, when the coil is wound around the teeth by concentrated winding, the exciting force acting on the teeth becomes larger than in the case where the coil is wound around the teeth by distributed winding. As a result, noise caused by the vibration of the teeth may be generated. Thus, in a rotating electric machine in which the coil is wound around the teeth by concentrated winding, it is also desirable to reduce the noise caused by vibration.

[0009] Technical solutions to solve problems

[0010] A rotating electric machine that solves the above-mentioned problem is a rotating electric machine having a rotor and a stator, wherein the rotor has a magnetic body and a shaft member that rotates integrally with the magnetic body, and the stator has a stator core and a coil. The rotating electric machine is characterized in that it has a bearing that supports the shaft member so that it can rotate relative to a housing that accommodates the rotating electric machine, and when a line extending in an orthogonal direction orthogonal to the axis of the shaft member is set as an orthogonal axis, the stator core has a cylindrical yoke body that extends along the axial direction of the shaft member and is centered on the axis, and a tooth that is located inside the yoke body and extends from the yoke body along the orthogonal axis. , the coil is wound around the tooth by concentrated winding, and when the point on the orthogonal axis of the center of the yoke is set as the center point, the dimension from the center point to the intersection of the orthogonal axis and the outer peripheral surface of the yoke is set as La / 2, the dimension from the center point to the intersection of the orthogonal axis and the end surface of the tooth is set as Lb / 2, the thickness of the yoke on the orthogonal axis is set as Lc, and the length of the tooth on the orthogonal axis is set as Ld, La / 2-Lb / 2=Lc+Ld, 0.15≤Lb / La≤0.35, and Lc / Ld≥0.35.

[0011] According to the above configuration, the ratio of the length of the teeth in the orthogonal direction to the size of the stator core becomes smaller than in the case where Lc / Ld < 0.35, so the teeth are less likely to vibrate with the driving of the rotating electric machine. In addition, compared with the case where Lc / Ld < 0.35, the natural vibration frequency in the rotating electric machine can be increased to a value outside the range of the operating frequency, so the resonance caused by the driving of the rotating electric machine can be suppressed. Therefore, in the case where the coil is wound around the teeth by concentrated winding, in the rotating electric machine that is prone to noise caused by the vibration of the teeth, the noise of the rotating electric machine generated by the vibration caused by the driving of the rotating electric machine can be reduced.

[0012] In a rotating electric machine, grooves may be formed inside the stator core, the grooves being spaces between adjacent teeth in the circumferential direction of the yoke body, six grooves being arranged in the circumferential direction of the yoke body, and the magnetic body being magnetized in the orthogonal direction and having two poles.

[0013] According to the above configuration, the stator has a vibration mode that is deformed into a second-order annular vibration mode. Therefore, compared with a case where the stator has a vibration mode that is deformed into a vibration mode other than the second-order annular vibration mode, the noise generated by the driving of the rotating electric machine tends to become larger. Therefore, by reducing the noise of the rotating electric machine generated by the vibration accompanying the driving of the rotating electric machine, the noise can be reduced even in the rotating electric machine that tends to have a larger noise as described above.

[0014] In a rotating electric machine, it is also possible that: the tooth has an axial tooth main body portion extending from the yoke body along the orthogonal direction, and a tooth front end portion, and when the end portion connected to the yoke body among the two end portions of the tooth main body portion in the orthogonal direction is set as the first end and the end portion on the opposite side of the first end is set as the second end, the tooth front end portion extends from the second end along the circumferential direction of the yoke body, and the coil is wound around the portion of the tooth main body portion on the yoke body side in the orthogonal direction and is not wound around the portion of the tooth main body portion on the tooth front end portion side in the orthogonal direction.

[0015] According to the above configuration, the coil is wound around the portion of the tooth body portion on the yoke body side in the orthogonal direction and is not wound around the portion of the tooth body portion on the tooth tip end side in the orthogonal direction. Therefore, compared with the case where the coil is wound around the entire tooth body portion in the orthogonal direction, the center of gravity of the tooth around which the coil is wound is shifted to the yoke body side in the orthogonal direction, thereby further reducing the vibration of the tooth accompanying the driving of the rotating electric machine. Therefore, the noise of the rotating electric machine generated by the vibration accompanying the driving of the rotating electric machine can be further reduced.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to reduce noise of a rotating electric machine generated by vibration accompanying driving of the rotating electric machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram schematically showing a cross section of a rotating electrical machine.

[0019] Figure 2 It is a cross-sectional view showing a rotating electrical machine.

[0020] Figure 3 It is a graph showing the natural vibration frequency and OA value in the comparative example and the working example.

[0021] Description of Reference Numerals

[0022] L1…axis line, L2…orthogonal axis line, P…center point, P1…first intersection point as intersection point, P2…second intersection point as intersection point, S1…groove, X…axial direction, Y…radial direction as orthogonal direction, 10…rotating electric machine, 11…housing, 14…bearing, 19…rotor, 30…magnetic body, 40…shaft member, 60…stator, 61…stator core, 62…coil, 71…yoke body, 71a…outer peripheral surface, 72…tooth, 73…tooth main body, 73a…first end, 73b…second end, 74…tooth tip end portion, 76…end surface. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments that embody the rotating electrical machine will be described with reference to the drawings.

[0024] <Basic structure of rotating electrical machines>

[0025] like Figure 1 As shown, the rotary electric machine 10 includes a rotor 19 and a stator 60. The rotary electric machine 10 is accommodated in a housing 11. The housing 11 includes a first housing component 12 and a plate-shaped second housing component 13. The first housing component 12 and the second housing component 13 are made of metal. The first housing component 12 and the second housing component 13 are made of, for example, aluminum.

[0026] The first housing component 12 has a plate-like bottom wall 12a and a peripheral wall 12b extending in a cylindrical shape from the outer peripheral end of the bottom wall 12a. One of the openings at both ends of the peripheral wall 12b is blocked by the bottom wall 12a, and the other opening is blocked by the second housing component 13. The second housing component 13 is connected to the first housing component 12 in a state where the opening of the peripheral wall 12b is blocked.

[0027] The first shell component 12 includes a cylindrical first boss portion 12c. The first boss portion 12c protrudes from the inner surface of the bottom wall 12a. The second shell component 13 includes a cylindrical second boss portion 13c. The second boss portion 13c protrudes from the inner surface of the second shell component 13. The axis of the first boss portion 12c, the axis of the second boss portion 13c, and the axis of the peripheral wall 12b of the first shell component 12 are consistent with each other.

[0028] The rotary electric machine 10 includes a bearing 14. The bearing 14 is disposed on each of the inner peripheral surface of the first boss portion 12c and the inner peripheral surface of the second boss portion 13c.

[0029] <Rotor Structure>

[0030] The rotor 19 is located inside the housing 11. The rotor 19 includes a magnetic body 30 and a shaft member 40 that rotates integrally with the magnetic body 30. The rotor 19 includes a cylindrical member 20, for example.

[0031] The barrel member 20 is cylindrical. The barrel member 20 is made of metal, for example. The axis of the barrel member 20 is consistent with the axis of the first boss portion 12c and the axis of the second boss portion 13c. Hereinafter, the direction in which the axis of the barrel member 20 extends is referred to as the axial direction X. The inner peripheral surface of the barrel member 20 is referred to as the barrel member inner surface 20a. The outer peripheral surface of the barrel member 20 is referred to as the barrel member outer surface 20b.

[0032] The opening at one end of the openings at both ends of the barrel member 20 in the axial direction X is referred to as the first opening 21, and the opening at the other end is referred to as the second opening 22. The first opening 21 and the second opening 22 are both circular holes. The inner diameter of the barrel member 20 is the same size in the entire axial direction X including the first opening 21 and the second opening 22. Hereinafter, the direction in which the inner diameter of the barrel member 20 extends is referred to as the radial direction Y.

[0033] <Composition of magnetic body>

[0034] The magnetic body 30 is, for example, cylindrical. The magnetic body 30 of the present embodiment is a permanent magnet. The magnetic body 30 is magnetized in the radial direction Y. The magnetic body 30 is composed of a first magnetic portion 30c and a second magnetic portion 30d. The first magnetic portion 30c is magnetized to an N pole. The second magnetic portion 30d is magnetized to an S pole. That is, the magnetic body 30 has two poles. The first magnetic portion 30c is, for example, a semi-cylindrical portion occupying one side of the magnetic body 30 in the radial direction Y. The second magnetic portion 30d is, for example, a semi-cylindrical portion occupying the other side of the magnetic body 30 in the radial direction Y.

[0035] The magnetic body 30 is arranged inside the barrel member 20. The axis of the magnetic body 30 is consistent with the axis of the barrel member 20. The diameter of the magnetic body 30 is the same size as the inner diameter of the barrel member 20. The direction in which the diameter of the magnetic body 30 extends is the same direction as the radial direction Y. The magnetic body 30 is pressed into the inside of the barrel member 20, for example. The outer surface 30a of the magnetic body 30 is in close contact with the inner surface 20a of the barrel member, and the magnetic body 30 is fixed to the inner surface 20a of the barrel member. One of the two ends in the axial direction X of the magnetic body 30 is called the first magnetic body end 31, and the other end is called the second magnetic body end 32.

[0036] <Configuration of shaft member>

[0037] The rotor 19 has, for example, two shaft members 40. One shaft member 40 may be referred to as a first shaft member 41, and the other shaft member 40 may be referred to as a second shaft member 51. The first shaft member 41 and the second shaft member 51 are, for example, cylindrical. The first shaft member 41 and the second shaft member 51 are, for example, made of metal.

[0038] The diameter of the first shaft member 41 and the second shaft member 51 is the same size as the inner diameter of the barrel member 20. The direction in which the diameters of the first shaft member 41 and the second shaft member 51 extend is the same direction as the radial direction Y. The axis of the first shaft member 41 and the axis of the second shaft member 51 coincide with each other. The axes of the first shaft member 41 and the second shaft member 51 are equivalent to the axis of the shaft member 40. The axis of the shaft member 40 is referred to as the axis L1. The axis L1 coincides with the axis of the barrel member 20, the axis of the first boss portion 12c, and the axis of the second boss portion 13c. The direction in which the axis L1 extends is the same direction as the axial direction X. The axial direction X is equivalent to the axial direction of the shaft member 40. The radial direction Y is equivalent to the orthogonal direction orthogonal to the axis L1.

[0039] The first shaft member 41 and the second shaft member 51 are pressed into the interior of the barrel member 20. The first shaft member 41 has a first pressed portion 43 pressed into the barrel member 20 and a first exposed portion 42 not pressed into the barrel member 20. The second shaft member 51 has a second pressed portion 53 pressed into the barrel member 20 and a second exposed portion 52 not pressed into the barrel member 20.

[0040] The first press-in portion 43 is located closer to the inside of the barrel member 20 than the first opening portion 21 of the barrel member 20 in the axial direction X. The first exposed portion 42 is exposed from the first opening portion 21 of the barrel member 20 to the outside of the barrel member 20 in the axial direction X. The second press-in portion 53 is located closer to the inside of the barrel member 20 than the second opening portion 22 of the barrel member 20 in the axial direction X. The second exposed portion 52 is exposed from the second opening portion 22 of the barrel member 20 to the outside of the barrel member 20 in the axial direction X.

[0041] The outer peripheral surface of the first exposed portion 42 is supported by the bearing 14 disposed on the inner peripheral surface of the first boss portion 12c. Thus, the first shaft member 41 is supported in a manner that can rotate relative to the housing 11. The outer peripheral surface of the second exposed portion 52 is supported by the bearing 14 disposed on the inner peripheral surface of the second boss portion 13c. Thus, the second shaft member 51 is supported in a manner that can rotate relative to the housing 11. Therefore, the bearing 14 supports the shaft member 40 so that it can rotate relative to the housing 11 that accommodates the rotating electrical machine 10.

[0042] The first outer peripheral surface 43a as the outer peripheral surface of the first press-in portion 43 and the second outer peripheral surface 53a as the outer peripheral surface of the second press-in portion 53 are in close contact with the inner surface 20a of the barrel member. Thus, the first shaft member 41 and the second shaft member 51 are fixed to the inner surface 20a of the barrel member. The first shaft member 41 and the second shaft member 51 can rotate integrally with the barrel member 20 and the magnetic body 30.

[0043] The first press-in portion 43 and the second press-in portion 53 are adjacent to the magnetic body 30 in the axial direction X. In other words, the shaft member 40 is adjacent to the magnetic body 30 in the axial direction X. The end of the first press-in portion 43 in the axial direction X is referred to as the first shaft member end 44. The end of the second press-in portion 53 in the axial direction X is referred to as the second shaft member end 54. The first shaft member end 44 is adjacent to the first magnetic body end 31 in the axial direction X. The second shaft member end 54 is adjacent to the second magnetic body end 32 in the axial direction X.

[0044] The first shaft member end 44 may be in contact with the first magnetic end 31 or away from the first magnetic end 31 in the axial direction X. The second shaft member end 54 may be in contact with the second magnetic end 32 or away from the second magnetic end 32 in the axial direction X.

[0045] The second exposed portion 52 penetrates the second housing component 13 and extends between the inside of the housing 11 and the outside of the housing 11 in the axial direction X. A rotating member (not shown) that rotates integrally with the second shaft member 51 may be connected to the end of the second exposed portion 52 located outside the housing 11. In this case, the rotation of the second shaft member 51 is transmitted as a driving force to the rotating member, thereby driving the rotating member to rotate. The rotating electric machine 10 in this embodiment is, for example, a so-called speed-type compressor having an impeller as a rotating member. Therefore, in the rotating electric machine 10 in this embodiment, the shaft member 40 rotates at a high speed.

[0046] <Stator structure>

[0047] The stator 60 is located inside the housing 11 . The stator 60 is located outside the rotor 19 in the radial direction Y. The stator 60 has a stator core 61 and a coil 62 .

[0048] <Construction of stator core>

[0049] The stator core 61 is configured, for example, by stacking a plurality of electromagnetic steel sheets 63 in the axial direction X. The stator core 61 has a first side surface 61 a at one end in the axial direction X and a second side surface 61 b ​​at the other end in the axial direction X.

[0050] like Figure 2 As shown, a line extending along a radial direction Y which is an orthogonal direction orthogonal to the axis L1 of the shaft member 40 is set as an orthogonal axis L2. The stator core 61, for example, has a yoke body 71 extending along the axial direction X, and teeth 72 located in the yoke body 71. The yoke body 71 is cylindrical with the axis L1 as the center. The yoke body 71 is, for example, cylindrical. The stator core 61 has, for example, 6 teeth 72. The teeth 72 extend from the yoke body 71 along the orthogonal axis L2.

[0051] A groove S1 is formed inside the stator core 61. The groove S1 is a space located between teeth 72 adjacent to each other in the circumferential direction of the yoke body 71. Six grooves S1 are arranged in the circumferential direction of the yoke body 71.

[0052] The tooth 72 has a tooth body 73 and a tooth tip 74. The tooth body 73 is axially shaped and extends from the yoke body 71 in the radial direction Y as the orthogonal direction. Of the two ends of the tooth body 73 in the radial direction Y as the orthogonal direction, the end connected to the yoke body 71 is set as the first end 73a, and the end on the opposite side of the first end 73a is set as the second end 73b. The tooth tip 74 extends from the second end 73b in the circumferential direction of the yoke body 71.

[0053] The tooth tip portion 74 has an end face 76 at the end on the opposite side of the end connected to the tooth main body 73 among the two end portions of the tooth tip portion 74 in the radial direction Y. The end face 76 of the tooth tip portion 74 defines an internal space S2. The end face 76 of the tooth tip portion 74 is located at the front end of the tooth 72 in the radial direction Y which is the orthogonal direction. Therefore, the end face 76 is also referred to as the end face 76 of the tooth 72 below. The end face 76 of the tooth tip portion 74 is a surface extending in a curved manner parallel to the inner peripheral surface of the yoke body 71. The internal space S2 passes through in the axial direction X. A cylindrical internal space S2 is defined inside the stator core 61 by the end faces 76 of each of the six teeth 72.

[0054] The magnetic body 30 is located in the internal space S2. In detail, the magnetic body 30 and the barrel member 20 are located in the internal space S2. In the cross-sectional shape of the stator core 61 and the barrel member 20 that are orthogonal to the axial direction X, the end face 76 of the tooth tip portion 74 faces the outer surface 20b of the barrel member. The end face 76 of the tooth tip portion 74 faces the outer surface 30a of the magnetic body 30 across the barrel member 20. The end face 76 of the tooth tip portion 74 is a curved surface extending along the outer surface 20b of the barrel member. The end face 76 of the tooth tip portion 74 leaves the outer surface 20b of the barrel member in the radial direction Y. Therefore, the end face 76 of the tooth tip portion 74 also leaves the outer surface 30a of the magnetic body 30 in the radial direction Y. The end face 76 of the tooth tip portion 74 is parallel to the outer surface 30a of the magnetic body 30.

[0055] A portion of the inner peripheral surface of the yoke body 71 and a portion of the outer surface of the tooth main body portion 73 are covered with a resin member 75. The resin member 75 is provided for each tooth 72.

[0056] like Figure 1 As shown, the outer peripheral surface 71a of the yoke 71 is fixed to the inner peripheral surface of the peripheral wall 12b of the first case component 12. By fixing the yoke 71 to the first case component 12 in this way, the stator core 61 is fixed to the case 11.

[0057] <Coil Structure>

[0058] like Figure 2 As shown, the coil 62 is wound around the tooth 72 by concentrated winding. The coil 62 is wound around the tooth body 73 from the outside of the resin member 75. The stator core 61 and the coil 62 are insulated by the resin member 75.

[0059] The coil 62 is wound around a portion of the tooth body 73 on the yoke body 71 side in the radial direction Y, which is the orthogonal direction, and is not wound around a portion of the tooth body 73 on the tooth tip end portion 74 side in the radial direction Y, which is the orthogonal direction. Thus, the coil 62 is wound around a portion of the tooth body 73 on the yoke body 71 side in the radial direction Y, rather than being closer to the tooth tip end portion 74 side.

[0060] The coil 62 includes a U-phase coil 62U, a V-phase coil 62V, and a W-phase coil 62W. A portion of each of the U-phase coil 62U, the V-phase coil 62V, and the W-phase coil 62W wound around the tooth 72 passes through the groove S1. The U-phase coil 62U, the V-phase coil 62V, and the W-phase coil 62W are each electrically connected to a converter (not shown). By supplying power from the converter to the U-phase coil 62U, the V-phase coil 62V, and the W-phase coil 62W, the rotor 19 can rotate.

[0061] like Figure 1 As shown, the coil 62 has a first coil end 62a and a second coil end 62b. The first coil end 62a protrudes from the first side surface 61a of the stator core 61 toward the bottom wall 12a of the first housing component 12. The second coil end 62b protrudes from the second side surface 61b of the stator core 61 toward the second housing component 13. Therefore, the first coil end 62a and the second coil end 62b are coil ends protruding from the side surface of the stator core 61 in the axial direction X.

[0062] The first coil end 62a surrounds the bearing 14 from the outside in the radial direction Y. Specifically, the first coil end 62a surrounds the first boss portion 12c and the bearing 14 disposed on the inner circumference of the first boss portion 12c from the outside in the radial direction Y. The first coil end 62a is separated from the first boss portion 12c in the radial direction Y. The second coil end 62b surrounds the bearing 14 from the outside in the radial direction Y. Specifically, the second coil end 62b surrounds the second boss portion 13c and the bearing 14 disposed on the inner circumference of the second boss portion 13c from the outside in the radial direction Y. The second coil end 62b is separated from the second boss portion 13c in the radial direction Y.

[0063] The bearing 14 disposed on the inner circumference of the first boss portion 12c is located between the first coil end 62a and the first exposed portion 42 in the radial direction Y. The bearing 14 disposed on the inner circumference of the second boss portion 13c is located between the second coil end 62b and the second exposed portion 52 in the radial direction Y. Therefore, the bearing 14 is located between the shaft member 40 in the radial direction Y as the orthogonal direction and the first coil end 62a and the second coil end 62b as the coil end. In the present embodiment, the first boss portion 12c and the bearing 14 disposed on the inner circumference of the first boss portion 12c are located between the first coil end 62a and the first exposed portion 42 in the radial direction Y. The second boss portion 13c and the bearing 14 disposed on the inner circumference of the second boss portion 13c are located between the second coil end 62b and the second exposed portion 52 in the radial direction Y.

[0064] <Dimensions of stator core>

[0065] like Figure 2 As shown, a point on the orthogonal axis L2 at the center of the yoke 71 is set as a center point P. The center point P is located on the axis L1 of the shaft member 40. The intersection of the orthogonal axis L2 and the outer peripheral surface 71a of the yoke 71 is set as a first intersection point P1. The dimension from the center point P to the first intersection point P1 is set as La / 2. La / 2 is equivalent to the outer diameter of the stator core 61. The intersection of the orthogonal axis L2 and the end surface 76 of the tooth 72 is set as the second intersection point P2. The dimension from the center point P to the second intersection point P2 is set as Lb / 2. Lb / 2 is equivalent to the inner diameter of the stator core 61. The thickness of the yoke 71 on the orthogonal axis L2 is set as Lc, and the length of the tooth 72 on the orthogonal axis L2 is set as Ld. Ld is equivalent to: the dimension in the radial direction Y between the extended surface V obtained by extending the inner peripheral surfaces of the yoke 71 sandwiching the tooth 72 in the circumferential direction of the yoke 71 and the end surface 76 of the tooth 72. Lc corresponds to the dimension obtained by subtracting Ld from the dimension in the radial direction Y between the outer peripheral surface 71a of the yoke body 71 and the end surface 76 of the tooth 72. La / 2-Lb / 2=Lc+Ld, 0.15≤Lb / La≤0.35. Lc / Ld≥0.35.

[0066] <Relationship between stator core size, natural vibration frequency, and OA value>

[0067] like Figure 3 As shown, the inventors of the present application measured the natural vibration frequency and OA value of the rotary electric machine 10 of each comparative example and embodiment when the shaft member 40 was rotated at a predetermined rotation speed. As comparative examples, the first comparative example A and the second comparative example B were measured. As embodiments, the first embodiment C, the second embodiment D, and the third embodiment E were measured. The OA value is an overall value, which indicates the magnitude of the sound generated in the rotary electric machine 10 of each example.

[0068] In the first comparative example A, the second comparative example B, the first example C, the second example D, and the third example E, La / 2 and Lb / 2 are each set to satisfy the relationship of 0.15≤Lb / La≤0.35. Lc and Ld are set in each example so that Lc / Ld increases in the order of the first comparative example A, the second comparative example B, the first example C, the second example D, and the third example E.

[0069] exist Figure 3 In the figure, the natural vibration frequency is represented by the blank plot, and the OA value is represented by the filled plot. The natural vibration frequency increases in the order of the first comparative example A, the second comparative example B, the first embodiment C, and the second embodiment D, and is slightly lower in the third embodiment E than in the second embodiment D. Therefore, Figure 3 As shown by the dotted line in the middle, it can be seen that the larger the Lc / Ld, the larger the natural vibration frequency. In contrast, the OA value decreases from the first comparative example A to the second comparative example B and the first example C, increases slightly from the first example C to the second example D, and decreases slightly from the second example D to the third example E.

[0070] The natural vibration frequency and OA value are usually in a relationship that the larger the natural vibration frequency, the smaller the OA value. Figure 3 The dashed lines in the figure show the Figure 3 The behavior of the OA value estimated from the measurement results of each example shown. This behavior shows different forms with Lc / Ld being 0.35 as the boundary. Specifically, in the range of Lc / Ld<0.35, it is shown that the OA value becomes smaller as Lc / Ld increases. In the range of Lc / Ld≥0.35, it is shown that the OA value remains almost the same even if Lc / Ld changes.

[0071] Therefore, according to the above measurement results, it is shown that in the rotating electrical machine 10 with Lc / Ld≥0.35, the noise generated accompanying driving is smaller than that in the rotating electrical machine 10 with Lc / Ld<0.35. In addition, it is shown that if Lc / Ld≥0.35, the above-mentioned effect of reducing the noise in the rotating electrical machine 10 can be obtained regardless of the size of Lc / Ld.

[0072] [Effects of implementation methods]

[0073] Next, the operation of this embodiment will be described.

[0074] In the case of the rotary electric machine 10 in which the shaft member 40 rotates at a high speed, in order to suppress the loss of the rotor 19, the size of the shaft member 40 in the radial direction Y is sometimes reduced. In particular, in the case of the rotary electric machine 10 being a speed type compressor, the rotation speed of the shaft member 40 is higher than that of a volume type compressor, and therefore, it is preferable to reduce the size of the shaft member 40 in the radial direction Y as described above. In such a case, in order to ensure the size of the gap between the shaft member 40 and the end face 76 of the tooth 72 in the radial direction Y at an appropriate value, it is necessary to reduce the size from the center point P of the yoke body 71 to the second intersection point P2, i.e., Lb / 2, by the size of the shaft member 40 described above. In addition, it is necessary to ensure the area occupied by the coil 62 inside the yoke body 71. In detail, since the size of the groove S1 where the coil 62 is located is smaller as it is closer to the rotor 19, it is necessary to ensure the area occupied by the coil 62 in the groove S1 by ensuring the length of the tooth 72. Therefore, there is a limit in reducing the size from the center point P to the first intersection point P1, i.e., La / 2. Thus, the ratio of La / 2 to Lb / 2 is within a specific range of 0.15≤Lb / La≤0.35. Thus, in the rotary electric machine 10 having the above ratio within the specific range, the longer Ld, which is the length of the tooth 72, the smaller Lc, which is the thickness of the yoke 71.

[0075] In the rotary electric machine 10 of the present embodiment, Lc / Ld≥0.35. By maintaining the size of Ld at a size that can ensure the area occupied by the coil 62 in the slot S1 as described above and increasing Lc, Lc / Ld≥0.35 is satisfied as described above. As a result, the ratio of the length of the tooth 72 in the radial direction Y to the size of the stator core 61 becomes smaller than in the case where Lc / Ld<0.35.

[0076] [Effects of Embodiment]

[0077] Next, the effects of this embodiment will be described.

[0078] (1) Lc / Ld≥0.35. Therefore, compared with the case where Lc / Ld<0.35, the ratio of the length of the tooth 72 in the radial direction Y to the size of the stator core 61 becomes smaller, so that the tooth 72 is less likely to vibrate with the driving of the rotating electric machine 10. In addition, compared with the case where Lc / Ld<0.35, the natural vibration frequency of the rotating electric machine 10 can be increased to a value outside the range of the operating frequency, so that the resonance caused by the driving of the rotating electric machine 10 can be suppressed. Therefore, in the case where the coil 62 is wound around the tooth 72 by concentrated winding, in the rotating electric machine 10 that is prone to noise caused by the vibration of the tooth 72, the noise of the rotating electric machine 10 generated by the vibration caused by the driving of the rotating electric machine 10 can be reduced.

[0079] (2) Grooves S1 are formed inside the stator core 61 as spaces between teeth 72 adjacent to each other in the circumferential direction of the yoke body 71. Six grooves S1 are arranged in the circumferential direction of the yoke body 71. The magnetic body 30 is magnetized in the radial direction Y and has two poles. Such a stator 60 has a vibration mode that is deformed into a second-order annular ring. Therefore, compared with the case where the stator 60 has a vibration mode that is deformed into a vibration mode other than the second-order annular ring, the noise generated by the driving of the rotating motor 10 tends to increase. Therefore, by reducing the noise of the rotating motor 10 generated by the vibration accompanying the driving of the rotating motor 10, the noise can be reduced even in the rotating motor 10 that tends to increase the noise as described above.

[0080] (3) The coil 62 is wound around the portion of the tooth body 73 on the yoke body 71 side in the radial direction Y, and is not wound around the portion of the tooth body 73 on the tooth tip end portion 74 side in the radial direction Y. Therefore, compared with the case where the coil 62 is wound around the entire tooth body 73 in the radial direction Y, the center of gravity of the tooth 72 around which the coil 62 is wound is shifted to the yoke body 71 side in the radial direction Y, thereby further reducing the vibration of the tooth 72 accompanying the driving of the rotating electric machine 10. Therefore, the noise of the rotating electric machine 10 generated by the vibration accompanying the driving of the rotating electric machine 10 can be further reduced.

[0081] (4) The coil 62 has a first coil end 62a and a second coil end 62b as coil ends. The first coil end 62a protrudes from a first side surface 61a which is a side surface of the stator core 61 in the axial direction X. The second coil end 62b protrudes from a second side surface 61b which is a side surface of the stator core 61 in the axial direction X. The bearing 14 is located between the shaft member 40 and the first coil end 62a and the second coil end 62b in the radial direction Y which is the orthogonal direction. In such a rotating electric machine 10, in order to provide a space in which the bearing 14 is arranged between the shaft member 40 and the first coil end 62a and the second coil end 62b, Ld which is the length of the tooth 72 is sometimes increased. In this way, even in the rotating electric machine 10 in which Ld is set to be large, the noise of the rotating electric machine 10 generated by the vibration of the tooth 72 accompanying the drive can be reduced.

[0082] [Example of Change]

[0083] The embodiment can be implemented by modification as follows. The embodiment and the following modified examples can be implemented in combination with each other within the range that there is no technical contradiction.

[0084] The yoke 71 may have a cylindrical shape other than the cylindrical shape, such as a polygonal cylindrical shape, for example.

[0085] The number of the grooves S1 formed inside the stator core 61 may be less than 6 or may be 7 or more. In this case, the number of teeth 72 included in the stator core 61 increases or decreases according to the number of the grooves S1.

[0086] The magnetic body 30 may have four or more poles.

[0087] The magnetic body 30 may be magnetized in a direction other than the radial direction Y. For example, the magnetic body 30 may be magnetized in the axial direction X.

[0088] The magnetic body 30 is not limited to a permanent magnet, and the magnetic body 30 may be, for example, a laminated core, an amorphous core, or a powder core.

[0089] The magnetic body 30 is not limited to a cylindrical shape, and may be, for example, a quadrangular column shape.

[0090] The magnetic body 30 is not limited to being adjacent to the shaft member 40 in the axial direction X. For example, the magnetic body 30 may be in a cylindrical shape extending in the axial direction X and may cover the shaft member 40 from the outside.

[0091] The first shaft member 41 may be omitted from the shaft member 40 .

[0092] The coil 62 may be wound around a portion of the tooth body 73 on the tooth tip end portion 74 side in the radial direction Y, and not wound around a portion of the tooth body 73 on the yoke 71 side in the radial direction Y. The coil 62 may be wound around a central portion of the tooth body 73 in the radial direction Y, and not wound around both ends of the tooth body 73 in the radial direction Y. The coil 62 may be wound around the entire tooth body 73 in the radial direction Y.

[0093] The stator core 61 is not limited to being formed by laminating a plurality of electromagnetic steel sheets 63. For example, the stator core 61 may be formed of a single member.

Claims

1. A rotating electric machine comprising a rotor and a stator, wherein the rotor comprises a magnetic body and a shaft member rotating integrally with the magnetic body, and the stator comprises a stator core and a coil, wherein the rotating electric machine is characterized in that: A bearing is provided for supporting the shaft member so as to be rotatable relative to a housing accommodating the rotating electrical machine. When a line extending in a direction orthogonal to the axis of the shaft member is defined as an orthogonal axis, The stator core includes a cylindrical yoke body extending along the axial direction of the shaft member and centered on the axis, and teeth located inside the yoke body and extending from the yoke body along the orthogonal axis. The coil is wound around the teeth by concentrated winding. When the point on the orthogonal axis at the center of the yoke is set as the center point, the dimension from the center point to the intersection of the orthogonal axis and the outer peripheral surface of the yoke is set as La / 2, the dimension from the center point to the intersection of the orthogonal axis and the end surface of the tooth is set as Lb / 2, the thickness of the yoke on the orthogonal axis is set as Lc, and the length of the tooth on the orthogonal axis is set as Ld, La / 2-Lb / 2=Lc+Ld, 0.15≤Lb / La≤0.35, and Lc / Ld≥0.

35.

2. The rotating electrical machine according to claim 1, characterized in that: A groove is formed inside the stator core, the groove being a space between the teeth adjacent to each other in the circumferential direction of the yoke body. There are six grooves arranged in the circumferential direction of the yoke body. The magnetic body is magnetized in the orthogonal direction and has two poles.

3. The rotating electrical machine according to claim 1 or 2, characterized in that: The tooth has an axial tooth body portion extending from the yoke body along the orthogonal direction, and a tooth tip portion. When the end connected to the yoke body among the two ends of the tooth body portion in the orthogonal direction is set as the first end and the end on the opposite side of the first end is set as the second end, The tooth tip portion extends from the second end along the circumferential direction of the yoke body, The coil is wound around a portion of the tooth body portion on the yoke body side in the orthogonal direction, and is not wound around a portion of the tooth body portion on the tooth tip end side in the orthogonal direction.

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