Motors, compressors, refrigeration equipment, blowers

Abstract

It suppresses harmonics contained in the magnetic flux linkage. [Solution] The magnetic path section (22) is formed to be convex toward the axis of rotation (Q). The first void section (31) is formed such that the radially outer side of the first void section (31) is open, or the radially outer side of the first void section (31) is closed, and the radially outer wall surface of the first void section (31) is convex toward the radially outer side. In a cross section perpendicular to the axis of rotation (Q), the first angle (θ1) is greater than or equal to the second angle (θ2), and less than or equal to N / 2 of the second angle (θ2).

Description

Technical Field

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[0001] The present disclosure relates to a motor, a compressor, a refrigeration device, and a blower.

Background Art

[0002] Patent Document 1 discloses a motor having a rotor and a stator. The stator includes a stator core composed of a plurality of teeth and a yoke, and concentrated winding type windings applied to the teeth. The rotor includes a rotor core and a plurality of permanent magnets embedded in the rotor core. The permanent magnets are formed in an arc shape convex toward the inner peripheral side of the rotor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the motor of Patent Document 1, it is difficult to suppress harmonics included in the interlinkage magnetic flux.

Means for Solving the Problems

[0005] The first aspect of the present disclosure relates to a motor, which includes <00,00031>a rotor (11) rotatable about a rotation axis line (Q), and a stator (12) disposed radially outside the rotor (11), the rotor (11) has a rotor core (20) made of a soft magnetic material, the rotor core (20) has a magnetic path portion (22) formed to be convex toward the rotation axis line (Q), and a first air gap portion (31) formed radially outside the magnetic path portion (22), the magnetic path portion (22) The first surface portion (22a) is a surface portion located on one end side in the circumferential direction of the first gap portion (31) and is a surface portion that constitutes a part of the outer circumferential surface of the rotor core (20), and is a surface portion that faces the inner circumference of the stator (12) in the radial direction, The first gap (31) has a surface portion located on the other end side in the circumferential direction, which constitutes a part of the outer circumferential surface of the rotor core (20), and has a second surface portion (22b) which is a surface portion that faces the inner circumference of the stator (12) in the radial direction, The first void (31) is formed such that its radially outer side is open, or its radially outer side is closed, and the radially outer wall surface of the first void (31) is convex radially outward. The stator (12) is A stator core (50) having a cylindrical yoke (51) and a plurality of teeth (52) arranged circumferentially on the radially inner side of the yoke (51), It has an N-phase coil (61) consisting of a conductor (60) wound around the plurality of teeth (52), The above N is an integer greater than or equal to 3, In a cross section perpendicular to the rotation axis (Q), the first angle (θ1) is defined as the angle formed by a first line (L1) hypothetically drawn as a line connecting the first end (E1), which is the end of the first surface portion (22a) closer to the second surface portion (22b), with the rotation axis (Q), and a second line (L2) hypothetically drawn as a line connecting the second end (E2), which is the end of the second surface portion (22b) closer to the first surface portion (22a), with the rotation axis (Q), and the circumference of the first tooth (52a), which is one of the plurality of teeth (52) When the second angle (θ2) is defined as the angle formed by a third line (L3) hypothetically drawn as a straight line connecting the center in the direction and the rotation axis (Q), and a fourth line (L4) hypothetically drawn as a straight line connecting the center in the circumferential direction of the second tooth (52b), which is a tooth (52) adjacent to the first tooth (52a) in the circumferential direction among the plurality of teeth (52), and the rotation axis (Q), then the first angle (θ1) is greater than or equal to the second angle (θ2) and less than or equal to N / 2 of the second angle (θ2).

[0006] In the first embodiment, the first gap (31) is formed radially outward from the magnetic path (22) such that the first angle (θ1) is greater than or equal to the second angle (θ2) and less than or equal to N / 2 of the second angle (θ2), thereby suppressing the abrupt flow of magnetic flux between the rotor (11) and the stator (12). This makes it possible to suppress harmonics included in the flux linkage.

[0007] A second aspect of this disclosure relates to the motor of the first aspect, When the minimum length of each of the plurality of teeth (52) in the circumferential direction is defined as the first length (D1), and 1 / 10 of the first length (D1) is defined as the second length (D2), the first region (R1), which is the region of the magnetic path portion (22) that extends radially inward from the first surface portion (22a) and whose radial length is the second length (D2), and the second region (R2), which is the region of the magnetic path portion (22) that extends radially inward from the second surface portion (22b) and whose radial length is the second length (D2), are regions where no gaps are formed. It is a motor.

[0008] In the second embodiment, by securing a first region (R1) and a second region (R2) at both ends in the circumferential direction of the magnetic path section (22), the flow of magnetic flux in the magnetic path section (22) can be ensured.

[0009] A third aspect of this disclosure relates to a motor of the first or second aspect, The rotor core (20) has an arc portion (23) that is provided radially outward from the first void portion (31) and closes the radially outward side of the first void portion (31). It is a motor.

[0010] In a third embodiment, the outer surface of the rotor core (20) can be made cylindrical. This reduces windage losses in the rotor (11).

[0011] A fourth aspect of the present disclosure is in any one of the motors of the first to third aspects, the rotor (11) has a first magnet (41), the first magnet (41) is disposed in the first air gap portion (31) is a motor.

[0012] In the fourth aspect, by disposing the first magnet (41) in the first air gap portion (31), the magnet torque resulting from the first magnet (41) can be added to the torque acting on the rotor (11). As a result, the torque acting on the rotor (11) can be increased.

[0013] A fifth aspect of the present disclosure is in any one of the motors of the first to fourth aspects, the rotor core (20) has a second air gap portion (32), the second air gap portion (32) is disposed radially inward of the magnetic path portion (22) is a motor.

[0014] In the fifth aspect, by providing the second air gap portion (32) radially inward of the magnetic path portion (22), the d-axis magnetic flux becomes less likely to pass radially inward of the magnetic path portion (22), so that the d-axis inductance can be reduced. As a result, the reluctance torque can be increased.

[0015] A sixth aspect of the present disclosure is in the motor of the fifth aspect, the rotor (11) has a second magnet (42), the second magnet (42) is disposed in the second air gap portion (32) is a motor.

[0016] In the sixth aspect, by disposing the second magnet (42) in the second air gap portion (32), the magnet torque resulting from the second magnet (42) can be added to the torque acting on the rotor (11). As a result, the torque acting on the rotor (11) can be increased.

[0017] The seventh aspect of the present disclosure is the motor according to the fifth or sixth aspect, wherein the second air gap portion (32) is formed so as to be convex toward the rotation axis (Q). It is a motor.

[0018] In the seventh aspect, by forming the second air gap portion (32) so as to be convex toward the rotation axis (Q), a magnetic path along the q-axis can be formed, so that the d-axis inductance can be reduced while suppressing the reduction of the q-axis inductance. As a result, the reluctance torque can be increased.

[0019] The eighth aspect of the present disclosure is the motor according to the fifth aspect, wherein the second air gap portion (32) is composed of a plurality of air gap portions (32a) arranged so as to be convex toward the rotation axis (Q). It is a motor.

[0020] In the eighth aspect, by configuring the second air gap portion (32) with a plurality of air gap portions (32a) arranged so as to be convex toward the rotation axis (Q), a magnetic path along the q-axis can be formed, so that the d-axis inductance can be reduced while suppressing the reduction of the q-axis inductance. As a result, the reluctance torque can be increased.

[0021] The ninth aspect of the present disclosure is the motor according to the eighth aspect, wherein the rotor (11) has a second magnet (42), the second magnet (42) is disposed in one of the plurality of air gap portions (32a) that constitute the second air gap portion (32). It is a motor.

[0022] In the ninth aspect, by disposing the second magnet (42) in one of the plurality of air gap portions (32a) that constitute the second air gap portion (32), the magnet torque caused by the second magnet (42) can be added to the torque acting on the rotor (11). Thereby, the torque acting on the rotor (11) can be increased.

[0023] A tenth aspect of this disclosure relates to a motor in any one of the first to ninth aspects, The N-phase coil (61) is composed of the conductor (60) wound around each of the plurality of teeth (52). It is a motor.

[0024] In the tenth embodiment, the conductor (60) can be wound around each of the multiple teeth (52) at a high density. This improves the efficiency of the motor (10).

[0025] An eleventh aspect of this disclosure relates to a compressor comprising a motor according to any one of the first to tenth aspects.

[0026] A twelfth aspect of this disclosure relates to a refrigeration system comprising a motor from any one of the first to tenth aspects.

[0027] A thirteenth aspect of this disclosure relates to a blower comprising a motor according to any one of the first to tenth aspects. [Brief explanation of the drawing]

[0028] [Figure 1] Figure 1 is a cross-sectional view illustrating the overall configuration of the motor according to the embodiment. [Figure 2] Figure 2 is a cross-sectional view illustrating the configuration of the motor according to the embodiment. [Figure 3] Figure 3 is a cross-sectional view illustrating the detailed configuration of the rotor of the embodiment. [Figure 4] Figure 4 is a cross-sectional view illustrating the configuration of the main parts of the rotor according to the embodiment. [Figure 5] Figure 5 is a graph illustrating the waveforms of flux linkage in concentrated windings and distributed windings, respectively. [Figure 6] Figure 6 is a cross-sectional view illustrating the configuration of a motor in a comparative example. [Figure 7] Figure 7 is a graph illustrating the waveform of the flux linkage in each of the embodiments and comparative examples (with magnets). [Figure 8]Figure 8 is a graph illustrating the waveform of the flux linkage in each of the embodiments and comparative examples (without magnets). [Figure 9] Figure 9 is a cross-sectional view illustrating the motor configuration of a modified example 1 of the embodiment. [Figure 10] Figure 10 is a longitudinal cross-sectional view illustrating the configuration of a compressor. [Figure 11] Figure 11 is a piping diagram illustrating the configuration of a refrigeration system. [Figure 12] Figure 12 is a schematic diagram illustrating the configuration of a blower. [Modes for carrying out the invention]

[0029] The embodiments will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated. Furthermore, this disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of ​​this disclosure. Since the drawings are for conceptual explanation of this disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for ease of understanding.

[0030] (Embodiment) Figures 1 and 2 illustrate the configuration of the motor (10) of the embodiment. The motor (10) comprises a rotor (11) that can rotate about a rotation axis (Q) and a stator (12). The rotor (11) is fixed to a shaft (15).

[0031] In the following explanation, the direction of the axis of rotation (Q) will be referred to as the "axial direction." The direction perpendicular to the axis of rotation (Q) will be referred to as the "radial direction." The direction around the axis of rotation (Q) will be referred to as the "circumferential direction." Furthermore, a cross-section along the axial direction will be referred to as the "longitudinal section." A cross-section perpendicular to the axial direction will be referred to as the "transverse section."

[0032] [Status] The stator (12) is positioned radially outward from the rotor (11). In this example, the stator (12) faces the rotor (11) with a predetermined gap between them. The stator (12) has a stator core (50) and N-phase (N is an integer of 3 or more) coils (61) formed by conductors (60).

[0033] The stator core (50) has a cylindrical yoke (51) and a plurality of teeth (52) arranged circumferentially on the radially inner side of the yoke (51). Each of the plurality of teeth (52) extends radially inward from the inner circumferential surface of the yoke (51). Slots for housing N-phase coils (61) are formed between the plurality of teeth (52).

[0034] The N-phase coil (61) consists of a conductor (60) wound around multiple teeth (52).

[0035] In the following explanation, a winding method of the conductor (60) where the number of slots per pole per phase is "1" or less will be described as "concentrated winding," and a winding method of the conductor (60) where the number of slots per pole per phase is greater than "1" will be described as "distributed winding." The number of slots per pole per phase is obtained by dividing the number of slots formed in the stator core (50) by the product of the "number of phases of the coil (61)" and the "number of poles of the rotor (11)."

[0036] In this example, the N-phase coil (61) is composed of a conductor (60) wound around each of the multiple teeth (52). Specifically, the conductor (60) is wound around the teeth (52) by concentrated winding.

[0037] [Rotor] The rotor (11) has a rotor core (20). The rotor (11) also has a first magnet (41) and a second magnet (42) for each magnetic pole. In this example, the rotor (11) has 6 magnetic poles, with 6 first magnets (41) arranged at equal intervals in the circumferential direction and 6 second magnets (42) arranged at equal intervals in the circumferential direction.

[0038] <Rotor Core> The rotor core (20) is made of a soft magnetic material. Furthermore, the rotor core (20) is composed of a laminated core. Specifically, the rotor core (20) is constructed by laminating multiple disc-shaped members, each made of electromagnetic steel sheet, in the axial direction. The cross-sectional shape of the rotor core (20) is identical along its entire axial length. In this example, the outer cross-sectional shape of the rotor core (20) is circular.

[0039] Furthermore, in this example, among the components of the rotor core (20), the "components provided for each magnetic pole of the rotor (11) (for example, the first air gap (31) described later)" are formed symmetrically with respect to a line axis extending radially from the rotation axis (Q) in a cross section perpendicular to the rotation axis (Q). In other words, a line axis of symmetry (imaginary line) is provided for each magnetic pole of the rotor (11), and the components included in that magnetic pole are formed symmetrically with respect to that line axis of symmetry.

[0040] <Axial hole> A shaft hole (30) is formed in the rotor core (20). The shaft hole (30) is located in the center of the rotor core (20) and penetrates the rotor core (20) in the axial direction. The cross-sectional shape of the shaft hole (30) is circular with respect to the axis of rotation (Q), and is the same along the entire axial length of the rotor core (20). The wall surface of the shaft hole (30) is cylindrical with respect to the axis of rotation (Q). A shaft (15) is inserted into and fixed in the shaft hole (30).

[0041] <Void area> The rotor core (20) has a first void (31) and a second void (32) formed for each magnetic pole of the rotor (11). In this example, six first voids (31) are arranged at equal intervals in the circumferential direction, and six second voids (32) are arranged at equal intervals in the circumferential direction. The second voids (32) are located radially outward from the shaft hole (30). The first voids (31) are located radially outward from the second voids (32).

[0042] The first void (31) is formed such that the radially outer side of the first void (31) is open, or the radially outer side of the first void (31) is closed, and the radially outer wall surface of the first void (31) is convex radially outward.

[0043] In this example, the configuration of the first void (31) is the latter configuration. The radially outer wall surface of the first void (31) is formed in the shape of an arc convex radially outward. The central surface of the radially inner wall surface of the first void (31) in the circumferential direction is formed in the shape of a plane perpendicular to the axis of symmetry described above. The end face surfaces of the radially inner wall surface of the first void (31) in the circumferential direction (faces adjacent to the central surface in the circumferential direction) are formed in the shape of a plane that is inclined with respect to the central surface and is aligned radially.

[0044] Furthermore, the first void (31) is located closer to the outer surface of the rotor core (20) rather than closer to the shaft hole (30). In other words, the shortest distance between the first void (31) and the axis of rotation (Q) is longer than half the shortest distance between the outer surface of the rotor core (20) and the axis of rotation (Q).

[0045] The second void (32) is formed to be convex toward the axis of rotation (Q). The radially outer wall surface and the radially inner wall surface of the second void (32) are formed in the shape of an arc that is convex toward the axis of rotation (Q).

[0046] <Rotor core configuration> The rotor core (20) has a base (21). The rotor core (20) also has a magnetic path section (22), an arc section (23), a first bridge (24), and a second bridge (25) for each magnetic pole of the rotor (11).

[0047] <base> The base portion (21) is the part between the shaft hole (30) and the multiple second gap portions (32). The radially outer wall surface of the base portion (21) has a surface portion that is convex toward the rotation axis (Q) for each magnetic pole of the rotor (11). The surface portion is formed in the shape of an arc convex toward the rotation axis (Q). The radially inner wall surface of the base portion (21) constitutes the wall surface of the shaft hole (30). In addition, protrusions are formed between adjacent surface portions in the circumferential direction, projecting radially outward.

[0048] <Magnetic circuit section> The magnetic path portion (22) is the portion between the first gap portion (31) and the second gap portion (32). The first gap portion (31) is formed radially outward from the magnetic path portion (22). The second gap portion (32) is positioned radially inward from the magnetic path portion (22).

[0049] The magnetic path section (22) is formed to be convex toward the axis of rotation (Q). The central surface of the radially outer wall of the magnetic path section (22) in the circumferential direction is formed as a plane perpendicular to the axis of symmetry. The end face portions of the radially outer wall of the magnetic path section (22) in the circumferential direction (faces adjacent to the central surface in the circumferential direction) are formed as a plane inclined with respect to the central surface and along the radial direction. The radially inner wall of the magnetic path section (22) is formed as an arc surface that is convex toward the axis of rotation (Q). The magnetic path section (22) has a first surface portion (22a) and a second surface portion (22b).

[0050] The first surface (22a) is a surface located on one end of the first gap (31) in the circumferential direction, and is a surface that constitutes a part of the outer circumferential surface of the rotor core (20), and is a surface that faces the inner circumference of the stator (12) in the radial direction.

[0051] The second surface (22b) is a surface located on the other end side in the circumferential direction of the first gap (31), and is a surface that constitutes a part of the outer circumferential surface of the rotor core (20), and is a surface that faces the inner circumference of the stator (12) in the radial direction.

[0052] Here, with reference to Figure 3, the detailed structure of the magnetic path section (22) will be described. In the following, the minimum length of each of the multiple teeth (52) in the circumferential direction (see Figure 2) will be referred to as the "first length (D1)", and 1 / 10 of the first length (D1) will be referred to as the "second length (D2)".

[0053] The first region (R1) of the magnetic path section (22), which is "the region extending radially inward from the first surface section (22a) and whose radial length is the second length (D2)," is a region where no void is formed. Similarly, the second region (R2) of the magnetic path section (22), which is "the region extending radially inward from the second surface section (22b) and whose radial length is the second length (D2)," is a region where no void is formed. In Figure 3, the first region (R1) and the second region (R2) are hatched.

[0054] <Arc section> The arc portion (23) is provided radially outward from the first gap portion (31) and closes the radially outward side of the first gap portion (31). Specifically, the radially outward wall surface of the arc portion (23) is a surface portion that constitutes a part of the outer circumferential surface of the rotor core (20) and is formed in the shape of an arc centered on the rotation axis (Q). The radially inward wall surface of the arc portion (23) is formed in the shape of an arc centered on the rotation axis (Q). The radial length of the arc portion (23) (the thickness of the arc portion (23)) is shorter than the second length (D2) described above.

[0055] <bridge> The first bridge (24) connects the first surface (22a) of the magnetic path section (22) to the protruding portion of the base (21), and closes one circumferential end of the second gap (32). The radially outer wall surface of the first bridge (24) is a surface that constitutes part of the outer circumferential surface of the rotor core (20), and is formed in the shape of an arc with respect to the rotation axis (Q). The radial length of the first bridge (24) (the thickness of the first bridge (24)) is shorter than the second length (D2) described above.

[0056] The second bridge (25) connects the second surface (22b) of the magnetic path section (22) to the protruding portion of the base (21), and closes the other circumferential end of the second gap (32). The radially outer wall surface of the second bridge (25) is a surface that constitutes part of the outer circumferential surface of the rotor core (20), and is formed in the shape of an arc with respect to the rotation axis (Q). The radial length of the second bridge (25) (the thickness of the second bridge (25)) is shorter than the second length (D2) described above.

[0057] 〔magnet〕 The first magnet (41) is placed in the first void (31). The cross-sectional shape of the first magnet (41) corresponds to the cross-sectional shape of the first void (31). The radially outer wall surface of the first magnet (41) is formed in the shape of an arc convex radially outward. The central surface of the radially inner wall surface of the first magnet (41) in the circumferential direction is formed in the shape of a plane perpendicular to the axis of symmetry described above. The end face surfaces of the radially inner wall surface of the first magnet (41) in the circumferential direction (faces adjacent to the central surface in the circumferential direction) are formed in the shape of a plane that is inclined with respect to the central surface and is aligned radially. For example, the first magnet (41) is a sintered magnet.

[0058] The second magnet (42) is placed in the second void (32). The cross-sectional shape of the second magnet (42) corresponds to the cross-sectional shape of the second void (32). The radially outer and radially inner walls of the second magnet (42) are formed in the shape of an arc that is convex toward the axis of rotation (Q). For example, the second magnet (42) is a sintered magnet.

[0059] [Detailed structure of the rotor core] Next, the detailed structure of the rotor core (20) will be described with reference to Figure 4.

[0060] In the following, the angle between the first line (L1) and the second line (L2) in a cross section perpendicular to the axis of rotation (Q) will be referred to as the "first angle (θ1)". The first line (L1) is a line drawn virtually as connecting the first end (E1), which is the end of the first surface (22a) closer to the second surface (22b), to the axis of rotation (Q). The second line (L2) is a line drawn virtually as connecting the second end (E2), which is the end of the second surface (22b) closer to the first surface (22a), to the axis of rotation (Q).

[0061] Furthermore, in the following, the angle between the third line (L3) and the fourth line (L4) in a cross section perpendicular to the axis of rotation (Q) will be referred to as the "second angle (θ2)". The third line (L3) is a line drawn virtually as connecting the circumferential center of the first tooth (52a), which is one of the multiple teeth (52), to the axis of rotation (Q). The fourth line (L4) is a line drawn virtually as connecting the circumferential center of the second tooth (52b), which is one of the multiple teeth (52) adjacent to the first tooth (52a) in the circumferential direction, to the axis of rotation (Q).

[0062] As shown in Figure 4, the first angle (θ1) is greater than or equal to the second angle (θ2), and less than or equal to N / 2 of the second angle (θ2). The various parts of the motor (10), particularly the magnetic path section (22) and the first air gap section (31), are formed so as to satisfy these conditions.

[0063] [Magnetic flux linkage] As shown in Figure 5, the distortion of the flux linkage (waveform distortion) in concentrated windings is greater than that in distributed windings, and the harmonics included in the flux linkage tend to be higher. This is presumed to be partly due to the fact that concentrated windings result in larger changes in the magnetic flux near the gap between the rotor (11) and the stator (12) than distributed windings.

[0064] If the harmonics included in the flux linkage are relatively large, the harmonics superimposed on the voltage applied to the motor (10) may also become large. Since it is necessary to add components such as filters to block these harmonics to the device that controls the motor (10) (e.g., a power converter), it is difficult to reduce costs.

[0065] Therefore, in the motor (10) of this embodiment, in order to suppress harmonics included in the flux linkage, the first air gap (31) is formed such that "either the radially outer side of the first air gap (31) is open, or the radially outer side of the first air gap (31) is closed so that the radially outer wall surface of the first air gap (31) is convex radially outward." Furthermore, in a cross section perpendicular to the axis of rotation (Q), each part of the motor (10) (especially the first air gap (31) and the magnetic path section (22)) is formed such that the first angle (θ1) is greater than or equal to the second angle (θ2) and less than or equal to N / 2 of the second angle (θ2).

[0066] [Comparison of the embodiment and the comparative example] Next, with reference to Figure 6, the motor (10) of the embodiment and the comparative example will be described in comparison. Figure 6 illustrates the configuration of the motor (90) of the comparative example.

[0067] The comparative example motor (90) shown in Figure 6 includes a rotor (91). The rotor (91) has a rotor core (92). The rotor core (92) has a first gap (93), an arc (94), and a first magnet (95) as shown in Figure 6, instead of the first gap (31), first magnet (41), and arc (23) shown in Figure 2. The other configurations of the comparative example motor (90) are the same as those of the motor (10) of the embodiment. For convenience of explanation, the reference numerals used for the components of the motor (10) of the embodiment are used in the description of the comparative example motor (90) below.

[0068] The radially outer wall surface of the first void (93) in the comparative example is formed in the shape of an arc convex with respect to the axis of rotation (Q). Similarly, the radially inner wall surface of the arc portion (94) in the comparative example is formed in the shape of an arc convex with respect to the axis of rotation (Q). The radially outer wall surface of the first magnet (95) in the comparative example is also formed in the shape of an arc convex with respect to the axis of rotation (Q).

[0069] In the comparative example motor (90), magnetic flux tends to flow easily into the arc portion (94) located radially outward from the first air gap (93), so the change in magnetic flux in the arc portion (94) tends to be steep. As a result, a rapid flow of magnetic flux is likely to occur between the rotor (91) and the stator (12), so the harmonics included in the flux linkage tend to be large.

[0070] On the other hand, in the motor (10) of the embodiment, the first gap (31) is formed such that the radially outer side of the first gap (31) is open, or the radially outer side of the first gap (31) is closed, and the radially outer wall surface of the first gap (31) is convex radially outward. Furthermore, in a cross section perpendicular to the axis of rotation (Q), each part of the motor (10) (especially the first gap (31) and the magnetic path section (22)) is formed such that the first angle (θ1) is greater than or equal to the second angle (θ2) and less than or equal to N / 2 of the second angle (θ2).

[0071] This configuration makes it difficult for magnetic flux to flow radially outward from the first gap (31), thereby suppressing the abrupt flow of magnetic flux between the rotor (11) and the stator (12). As a result, harmonics included in the flux linkage are suppressed.

[0072] Figure 7 shows the waveforms of the flux linkage in the motor (10) of the embodiment and the motor (90) of the comparative example, in the state where the first magnet (41) and the second magnet (42) are arranged in the first air gap (31) and the second air gap (32), respectively. As shown in Figure 7, the motor (10) of the embodiment has less distortion in the flux linkage and fewer harmonics in the flux linkage than the motor (90) of the comparative example. In the example in Figure 7, the distortion rate of the flux linkage in the motor (90) of the comparative example is "11.9%", and the distortion rate of the flux linkage in the motor (10) of the embodiment is "4.6%".

[0073] Figure 8 shows the flux linkage waveforms for the motor (10) of the embodiment and the motor (90) of the comparative example in the state where the first magnet (41) and the second magnet (42) are not positioned in the first air gap (31) and the second air gap (32), respectively. As shown in Figure 8, the motor (10) of the embodiment has less distortion in the flux linkage and fewer harmonics in the flux linkage than the motor (90) of the comparative example. In the example in Figure 8, the flux linkage distortion rate for the motor (90) of the comparative example is "4.4%", and the flux linkage distortion rate for the motor (10) of the embodiment is "3.4%".

[0074] [Effects of the Embodiment] As described above, in the motor (10) of the embodiment, the rotor core (20) has a magnetic path portion (22) formed to be convex toward the rotation axis (Q), and a first void portion (31) formed radially outward from the magnetic path portion (22). The first void portion (31) is formed such that the radially outward side of the first void portion (31) is open, or the radially outward side of the first void portion (31) is closed, and the radially outward wall surface of the first void portion (31) is convex radially outward. In a cross section perpendicular to the rotation axis (Q), the first angle (θ1) is greater than or equal to the second angle (θ2), and less than or equal to N / 2 of the second angle (θ2).

[0075] In the above configuration, by forming the first air gap (31) radially outward from the magnetic path (22) such that the first angle (θ1) is greater than or equal to the second angle (θ2) and less than or equal to N / 2 of the second angle (θ2), the abrupt flow of magnetic flux between the rotor (11) and the stator (12) can be suppressed. This makes it possible to suppress harmonics included in the flux linkage.

[0076] Specifically, by forming the first gap (31) and the magnetic path (22) such that the first angle (θ1) is greater than or equal to the second angle (θ2), the abrupt flow of magnetic flux between the rotor (11) and the stator (12) can be suppressed, thereby suppressing harmonics included in the flux linkage.

[0077] Furthermore, by forming the first gap (31) and the magnetic path (22) such that the first angle (θ1) is N / 2 or less of the second angle (θ2), the configuration of the first gap (31) and the magnetic path (22) can be made suitable for concentrated winding. This makes it possible to adopt a concentrated winding method that allows for high-density winding of the conductor (60) around the teeth (52), thereby improving the efficiency of the motor (10).

[0078] Furthermore, in the motor (10) of the embodiment, if the minimum value of the circumferential length of each of the multiple teeth (52) is defined as the "first length (D1)", and 1 / 10 of the first length (D1) is defined as the "second length (D2)", then the first region (R1), which is the region of the magnetic path section (22) extending radially inward from the first surface (22a) and whose radial length is the second length (D2), and the second region (R2), which is the region of the magnetic path section (22) extending radially inward from the second surface (22b) and whose radial length is the second length (D2), are regions where no gap is formed.

[0079] In the above configuration, by securing a first region (R1) and a second region (R2) at both ends in the circumferential direction of the magnetic path section (22), the flow of magnetic flux in the magnetic path section (22) can be ensured.

[0080] Furthermore, in the motor (10) of the embodiment, the rotor core (20) has an arc portion (23) that is provided radially outward from the first gap portion (31) and closes the radially outward side of the first gap portion (31).

[0081] In the above configuration, the outer surface of the rotor core (20) can be made cylindrical. This reduces windage losses in the rotor (11).

[0082] Furthermore, in the motor (10) of the embodiment, the rotor (11) has a first magnet (41). The first magnet (41) is arranged in the first gap (31).

[0083] In the above configuration, by placing the first magnet (41) in the first gap (31), the magnetic torque caused by the first magnet (41) can be added to the torque acting on the rotor (11). This makes it possible to increase the torque acting on the rotor (11).

[0084] Furthermore, in the motor (10) of the embodiment, the rotor core (20) has a second gap (32). The second gap (32) is located radially inward from the magnetic path (22).

[0085] In the above configuration, by providing the second air gap (32) radially inward from the magnetic path (22), the d-axis magnetic flux becomes less likely to pass radially inward from the magnetic path (22), thereby reducing the d-axis inductance. As a result, the reluctance torque can be increased.

[0086] Furthermore, in the motor (10) of the embodiment, the rotor (11) has a second magnet (42). The second magnet (42) is arranged in the second gap (32).

[0087] In the above configuration, by placing the second magnet (42) in the second gap (32), the magnetic torque caused by the second magnet (42) can be added to the torque acting on the rotor (11). This makes it possible to increase the torque acting on the rotor (11).

[0088] Furthermore, in the motor (10) of the embodiment, the second gap (32) is formed to be convex toward the axis of rotation (Q).

[0089] In the above configuration, by forming the second air gap (32) so as to be convex toward the rotation axis (Q), a magnetic path along the q-axis can be formed, thereby reducing the d-axis inductance while suppressing the decrease in the q-axis inductance. As a result, the reluctance torque can be increased.

[0090] Furthermore, in the motor (10) of the embodiment, the N-phase coil (61) is composed of a conductor (60) wound around each of the multiple teeth (52).

[0091] In the above configuration, the conductor (60) can be wound around each of the multiple teeth (52) at high density. This improves the efficiency of the motor (10).

[0092] (Modified version of the embodiment) Figure 9 illustrates the configuration of a modified motor (10) of the embodiment. The configuration of the second gap (32) and the second magnet (42) of the modified motor (10) of the embodiment differs from that of the motor (10) of the embodiment. The other configurations of the modified motor (10) of the embodiment are the same as those of the motor (10) of the embodiment.

[0093] In the modified motor (10) of the embodiment, the second void (32) is composed of a plurality of voids (32a). The plurality of voids (32a) are arranged to be convex toward the axis of rotation (Q). In the example of Figure 9, three voids (32a) are arranged in a U-shape to constitute one second void (32). The cross-sectional shape of the void (32a) is rectangular.

[0094] Furthermore, in the modified motor (10) of the embodiment, the second magnet (42) is composed of a plurality of magnets (42a). The plurality of magnets (42a) constituting the second magnet (42) are each arranged in the plurality of voids (32a) constituting the second void (32). In the example of Figure 9, the cross-sectional shape of the magnet (42a) is rectangular. For example, the magnet (42a) is a sintered magnet.

[0095] [Effects of modified embodiments] In the modified motor (10) of the embodiment, the same effects as those of the motor (10) of the embodiment can be obtained. For example, harmonics included in the flux linkage can be suppressed.

[0096] Furthermore, in the modified motor (10) of the embodiment, the second gap (32) is composed of a plurality of gaps (32a) arranged to be convex toward the axis of rotation (Q).

[0097] In the above configuration, a magnetic path along the q-axis can be formed by configuring a second air gap (32) with multiple air gaps (32a) arranged to be convex toward the rotation axis (Q), thereby reducing the d-axis inductance while suppressing the decrease in the q-axis inductance. As a result, the reluctance torque can be increased.

[0098] Furthermore, in the motor (10) of the modified embodiment, the rotor (11) has a second magnet (42). The second magnet (42) is arranged in one of the plurality of gaps (32a) that constitute the second gap (32).

[0099] In the above configuration, by placing the second magnet (42) in one of the multiple gaps (32a) that make up the second gap (32), the magnetic torque caused by the second magnet (42) can be added to the torque acting on the rotor (11). This makes it possible to increase the torque acting on the rotor (11).

[0100] (Compressor) Figure 10 illustrates the configuration of a compressor (CC). The compressor (CC) comprises a motor (10), a casing (CC1), and a compression mechanism (CC2).

[0101] The casing (CC1) houses the compression mechanism (CC2) and the motor (10). In this example, the casing (CC1) is formed in a cylindrical shape that extends vertically and is closed at both ends. The casing (CC1) is provided with an intake pipe (CC11) and a discharge pipe (CC12). The intake pipe (CC11) passes through the body of the casing (CC1) and is connected to the compression mechanism (CC2). The discharge pipe (CC12) passes through the top of the casing (CC1) and communicates with the internal space of the casing (CC1).

[0102] The compression mechanism (CC2) compresses the fluid. In this example, the compression mechanism (CC2) is located below the motor (10). The compression mechanism (CC2) compresses the fluid drawn in through the intake pipe (CC11) and discharges the compressed fluid into the internal space of the casing (CC1). The fluid discharged into the internal space of the casing (CC1) is then discharged through the discharge pipe (CC12).

[0103] The shaft (15) connects the motor (10) and the compression mechanism (CC2). In this example, the shaft (15) extends vertically. The motor (10) rotates the shaft (15). The rotational drive of the shaft (15) drives the compression mechanism (CC2).

[0104] Note that the drive method for the compressor (CC) is not limited to the drive method shown in Figure 10. For example, the compressor (CC) may be a scroll type, screw type, turbo type, or other type of compressor.

[0105] (Refrigeration equipment) Figure 11 illustrates the configuration of a refrigeration system (RR). The refrigeration system (RR) comprises a refrigerant circuit (RR1) through which the refrigerant circulates, a first blower (RR5a), and a second blower (RR6a). The refrigerant circuit (RR1) includes a compressor (CC) with a motor (10), a first heat exchanger (RR5), a second heat exchanger (RR6), an expansion mechanism (RR7), and a four-way switching valve (RR8). In this example, the expansion mechanism (RR7) is an electronic expansion valve. The refrigerant circuit (RR1) performs a vapor compression type refrigeration cycle. For example, the first heat exchanger (RR5) is a heat source heat exchanger and is located outside the room. The second heat exchanger (RR6) is a utilization heat exchanger and is located inside the room. The first blower (RR5a) transports air to the first heat exchanger (RR5). The second blower (RR6a) delivers air to the second heat exchanger (RR6).

[0106] The discharge side of the compressor (CC) is connected to the first port (P1) of the four-way directional control valve (RR8). The suction side of the compressor (CC) is connected to the second port (P2) of the four-way directional control valve (RR8). The gas end of the first heat exchanger (RR5) is connected to the third port (P3) of the four-way directional control valve (RR8). The liquid end of the first heat exchanger (RR5) is connected to the liquid end of the second heat exchanger (RR6) via the expansion mechanism (RR7). The gas end of the second heat exchanger (RR6) is connected to the fourth port (P4) of the four-way directional control valve (RR8).

[0107] The four-way switching valve (RR8) can be switched between a first state (shown by the solid line in Figure 11) in which the first port (P1) and the third port (P3) are in communication and the second port (P2) and the fourth port (P4) are in communication, and a second state (shown by the dashed line in Figure 11) in which the first port (P1) and the fourth port (P4) are in communication and the second port (P2) and the third port (P3) are in communication.

[0108] When the four-way switching valve (RR8) is in the first state, the refrigerant discharged from the compressor (CC) dissipates heat in the first heat exchanger (RR5), is depressurized in the expansion mechanism (RR7), and then absorbs heat in the second heat exchanger (RR6). The refrigerant flowing out of the second heat exchanger (RR6) is drawn into the compressor (CC).

[0109] When the four-way switching valve (RR8) is in the second state, the refrigerant discharged from the compressor (CC) dissipates heat in the second heat exchanger (RR6), is depressurized in the expansion mechanism (RR7), and then absorbs heat in the first heat exchanger (RR5). The refrigerant flowing out of the first heat exchanger (RR5) is drawn into the compressor (CC).

[0110] For example, the refrigeration unit (RR) is an air conditioner that switches between cooling and heating. The refrigeration unit (RR) may be a cooling-only unit or a heating-only unit. In this case, the four-way switching valve (RR8) may be omitted from the refrigeration unit (RR). Furthermore, the refrigeration unit (RR) may be a water heater, chiller unit, or cooling device that cools the air inside a storage unit. The cooling device cools the air inside refrigerators, freezers, containers, etc.

[0111] (Blower) Figure 12 illustrates the configuration of a blower (FF). The blower (FF) is installed in a flow path (not shown) and transports fluid. The blower (FF) has a rotating body (FF1) with blades and a motor (10). The rotating body (FF1) is connected to the motor (10) by a shaft (15). The motor (10) rotates the rotating body (FF1) by rotating its rotating shaft.

[0112] (Other embodiments) The above explanation may be structured as follows:

[0113] The first magnet (41) may or may not be embedded so as to fill the entire area of ​​the first void (31) without any gaps. Similarly, the second magnet (42) may or may not be embedded so as to fill the entire area of ​​the second void (32) without any gaps.

[0114] The rotor (11) does not have to have the first magnet (41). Similarly, the rotor (11) does not have to have the second magnet (42).

[0115] The radially inner shape of the first void (31) is not limited to a shape that is convex toward the axis of rotation (Q). For example, the radially inner wall surface of the first void (31) may be formed in a planar shape perpendicular to the axis of symmetry (a plane that is linear in a cross-section perpendicular to the axis of rotation (Q)). By making it planar, the magnet can have a linear portion, making magnet manufacturing easier. It is desirable that the width of the end at the center of the magnetic path (22) be wider than the width of the end in the circumferential direction of the magnetic path (22). In order to realize such a configuration, the radially inner shape of the first void (31) (shape in a cross-section perpendicular to the axis of rotation (Q)) may be the following shape.

[0116] (1) The central surface of the radially inner wall of the first void (31) in the circumferential direction is formed in a planar shape perpendicular to the axis of symmetry (a plane that is straight in a cross section perpendicular to the axis of rotation (Q)). (2) The radially inner wall surface of the first void (31) is an arc-shaped surface that is convex with respect to the axis of rotation (Q), and the center of curvature of the radially inner wall surface of the first void (31) is located radially outward from the center of curvature of the radially outer wall surface of the second void (32) (the arc-shaped wall surface that is convex with respect to the axis of rotation (Q)). (3) The shape is such that the radially inner wall surface of the first void (31) is concave with respect to the axis of rotation (Q). By adopting the shape described above, the width of the central part in the circumferential direction of the magnetic path section (22) can be increased. This allows for a higher q-axis inductance and an increase in reluctance torque. Furthermore, it allows for space to be secured for bolt holes and other components, thereby improving the design flexibility of the rotor core (20).

[0117] Furthermore, the shape of the arc portion (23) is not limited to an arc shape centered on the axis of rotation (Q).

[0118] For example, the arc portion (23) may be an arc shape having two or more centers of curvature. Also, the radial length of the arc portion (23) may be the same or different throughout the entire circumferential region of the arc portion (23). Since the stress acting on the arc portion (23) due to the centrifugal force corresponding to the rotation of the rotor (11) differs depending on the location, the center of curvature and radial length of the arc portion (23) may be changed as described above in accordance with such differences in stress at different locations.

[0119] Furthermore, the radial length of the arc portion (23) may be less than or equal to the second length (D2) described above. This configuration prevents the arc portion (23) from becoming a magnetic path (a portion through which magnetic flux flows).

[0120] Furthermore, although the example given was that a first gap (31) is provided for each magnetic pole of the rotor (11), the invention is not limited to this. For example, the first gap (31) may not be provided for all magnetic poles of the rotor (11), but for some of the magnetic poles of the rotor (11). The same applies to other "components provided for each magnetic pole of the rotor (11) (e.g., magnetic path section (22), etc.)".

[0121] Furthermore, while embodiments and modifications have been described, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Also, elements of the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate. Moreover, the designations "first," "second," "third," etc., in the specification and claims are used to distinguish the phrases to which these designations are given, and do not limit the number or order of such phrases. [Industrial applicability]

[0122] As described above, this disclosure is useful as a motor, compressor, refrigeration device, blower, etc. [Explanation of symbols]

[0123] 10 motors 11 rotors 12 staters 20 rotor cores 21 Base 22 Magnetic circuit section 23. Arc section 30 shaft holes 31 First cavity 32 Second cavity 32a Cavity 41 First Magnet 42. Second Magnet 42a Magnet 50 stator cores 51 York 52 Teeth 52a First Teeth 52b Second Teeth 60 Conductor 61 coils L1 1st straight line L2 2nd straight line L3 3rd straight line L4 Fourth Straight Line θ1 1st angle θ2 2nd angle

Claims

1. A rotor (11) that can rotate around the axis of rotation (Q), The rotor (11) is further equipped with a stator (12) positioned radially outward from it. The rotor (11) has a rotor core (20) made of a soft magnetic material, The rotor core (20) is A magnetic path portion (22) formed to be convex toward the rotation axis (Q), It has a first void portion (31) formed radially outward from the magnetic path portion (22), The aforementioned magnetic circuit section (22) is The first surface portion (22a) is a surface portion located on one end side in the circumferential direction of the first gap portion (31) and is a surface portion that constitutes a part of the outer circumferential surface of the rotor core (20), and is a surface portion that faces the inner circumference of the stator (12) in the radial direction, The first gap (31) has a surface portion located on the other end side in the circumferential direction, which is a surface portion that constitutes a part of the outer circumferential surface of the rotor core (20), and has a second surface portion (22b) that is a surface portion that faces the inner circumference of the stator (12) in the radial direction, The first void (31) is formed such that the radially outer side of the first void (31) is open, or the radially outer side of the first void (31) is closed, and the radially outer wall surface of the first void (31) is convex radially outward. The stator (12) is A stator core (50) having a cylindrical yoke (51) and a plurality of teeth (52) arranged circumferentially on the radially inner side of the yoke (51), It has an N-phase coil (61) consisting of a conductor (60) wound around the plurality of teeth (52), The aforementioned N is an integer greater than or equal to 3, In a cross section perpendicular to the rotation axis (Q), the first angle (θ1) is defined as the angle formed by a first line (L1) hypothetically drawn as a line connecting the first end (E1), which is the end of the first surface (22a) closer to the second surface (22b), with the rotation axis (Q), and a second line (L2) hypothetically drawn as a line connecting the second end (E2), which is the end of the second surface (22b) closer to the first surface (22a), with the rotation axis (Q), and the circumference of the first tooth (52a), which is one of the plurality of teeth (52) When the second angle (θ2) is defined as the angle formed by a third line (L3) hypothetically drawn as a line connecting the center in the direction and the rotation axis (Q), and a fourth line (L4) hypothetically drawn as a line connecting the center in the circumferential direction of the second tooth (52b), which is a tooth (52) adjacent to the first tooth (52a) in the circumferential direction among the plurality of teeth (52), and the rotation axis (Q), then the first angle (θ1) is greater than or equal to the second angle (θ2) and less than or equal to N / 2 of the second angle (θ2). The minimum length of each of the plurality of teeth (52) in the circumferential direction is defined as the first length (D1). The second length (D2) is set to 1 / 10 of the first length (D1). The first region (R1) is defined as the entire region on one circumferential end side of the first void (31) extending radially inward from the outer circumferential surface of the rotor core (20), having a radial length equal to the second length (D2), and where no void is formed. When the region extending radially inward from the outer circumferential surface of the rotor core (20) on the other end side of the first gap (31), and the radial length is the second length (D2), and the entire region where no gap is formed is defined as the second region (R2), The first end (E1) of the first surface portion (22a) is the intersection point of the edge of the first region (R1) closest to the second surface portion (22b) and the outer circumferential surface of the rotor core (20) in a cross section perpendicular to the axis of rotation (Q). The second end (E2) of the second surface (22b) is the intersection point of the edge of the second region (R2) closest to the first surface (22a) and the outer circumferential surface of the rotor core (20) in a cross section perpendicular to the axis of rotation (Q). Motor.

2. In the motor according to claim 1, The rotor core (20) has an arc portion (23) provided radially outward from the first void portion (31) and closing the radially outward side of the first void portion (31). Motor.

3. In the motor according to claim 1, The rotor (11) has a first magnet (41), The first magnet (41) is placed in the first gap (31). Motor.

4. In the motor according to claim 1, The rotor core (20) has a second void (32), The second void (32) is positioned radially inward from the magnetic path (22). Motor.

5. In the motor according to claim 4, The rotor (11) has a second magnet (42), The second magnet (42) is placed in the second gap (32). Motor.

6. In the motor according to claim 4, The second gap (32) is formed to be convex toward the axis of rotation (Q). Motor.

7. In the motor according to claim 4, The second void (32) is composed of a plurality of voids (32a) arranged to be convex toward the axis of rotation (Q). Motor.

8. In the motor according to claim 7, The rotor (11) has a second magnet (42), The second magnet (42) is placed in one of the plurality of gaps (32a) that constitute the second gap (32). Motor.

9. In the motor according to claim 1, The N-phase coil (61) is composed of the conductor (60) wound around each of the plurality of teeth (52). Motor.

10. A compressor comprising one of the motors described in claims 1 to 9.

11. A refrigeration apparatus comprising one motor according to any one of claims 1 to 9.

12. A blower comprising one motor according to any one of claims 1 to 9.

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