Motor, compressor, refrigeration device, and blower

Abstract

A magnetic path part (22) is formed in a state of protruding toward the rotation axis (Q). A first void part (31) is formed such that the radially outer side of the first void part (31) is open, or the radially outer side of the first void part (31) is closed and the wall surface of the first void part (31) on the radially outer side protrudes toward the radially outer side. In a cross-section perpendicular to the rotation axis (Q), a first angle (θ1) is larger than or equal to a second angle (θ2) and is less than or equal to N / 2 of the second angle (θ2).

Description

Motor, compressor, refrigeration device, blower

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

[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 a concentrated winding type winding applied to the teeth. The rotor includes a rotor core and a plurality of permanent magnets embedded in the rotor core. The permanent magnet is formed in an arc shape convex on the inner peripheral side of the rotor.

[0003] Japanese Patent Application Laid-Open No. 2000-50543

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

[0005] A first aspect of the present disclosure relates to a motor, the motor comprising: a rotor (11) rotatable about a rotation axis (Q); and a stator (12) positioned radially outward from the rotor (11), wherein 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 (Q), and a first void portion (31) formed radially outward from the magnetic path portion (22), the magnetic path portion (22) has a surface portion located at one end of the first void portion (31) in the circumferential direction and constituting a part of the outer circumferential surface of the rotor core (20), and a first surface portion (22a) which is a surface portion facing radially from the inner circumference of the stator (12), The first void (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) 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 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) has a stator core (50) having a cylindrical yoke (51) and a plurality of teeth (52) arranged in the circumferential direction on the radially inner side of the yoke (51), and an N-phase coil (61) consisting of a conductor (60) wound around the plurality of teeth (52), where N is an integer of 3 or more,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).

[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 is a motor according to the first aspect, wherein 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) of the magnetic path portion (22) is the region extending radially inward from the first surface portion (22a) and the radial length is the second length (D2), and the second region (R2) of the magnetic path portion (22) is the region extending radially inward from the second surface portion (22b) and the radial length is the second length (D2), are regions in which no air gap is formed.

[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 the present disclosure is a motor according to the first or second aspect, wherein the rotor core (20) has an arc portion (23) provided radially outward from the first gap (31) and closing the radially outward side of the first gap (31).

[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 a motor in any one of the first to third aspects, wherein the rotor (11) has a first magnet (41), and the first magnet (41) is disposed in the first gap (31).

[0012] In the fourth embodiment, by arranging 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).

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

[0014] In the fifth embodiment, 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.

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

[0016] In the sixth embodiment, by arranging a 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).

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

[0018] In the seventh embodiment, by forming the second 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.

[0019] An eighth aspect of the present disclosure is a motor according to the fifth aspect, wherein the second gap (32) is composed of a plurality of gaps (32a) arranged to be convex toward the rotation axis (Q).

[0020] In the eighth aspect, a magnetic path along the q-axis can be formed by configuring a second gap (32) with a plurality of 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.

[0021] A ninth aspect of the present disclosure is a motor according to the eighth aspect, wherein the rotor (11) has a second magnet (42), and the second magnet (42) is positioned in one of the plurality of gaps (32a) that constitute the second gap (32).

[0022] In the ninth embodiment, by arranging a second magnet (42) in one of the multiple gaps (32a) constituting 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).

[0023] A tenth aspect of the present disclosure is a motor in which, 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).

[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 equipped with a motor according to any one of the first to tenth aspects.

[0028] Figure 1 is a cross-sectional view illustrating the overall configuration of the motor of the embodiment. Figure 2 is a cross-sectional view illustrating the configuration of the motor of the embodiment. Figure 3 is a cross-sectional view illustrating the detailed configuration of the rotor of the embodiment. Figure 4 is a cross-sectional view illustrating the configuration of the main part of the rotor of the embodiment. Figure 5 is a graph illustrating the waveform of flux linkage in concentrated winding and distributed winding, respectively. Figure 6 is a cross-sectional view illustrating the configuration of a motor of a comparative example. Figure 7 is a graph illustrating the waveform of flux linkage in the embodiment and comparative example (with magnets), respectively. Figure 8 is a graph illustrating the waveform of flux linkage in the embodiment and comparative example (without magnets), respectively. Figure 9 is a cross-sectional view illustrating the configuration of a motor of modified example 1 of the embodiment. Figure 10 is a longitudinal cross-sectional view illustrating the configuration of a compressor. Figure 11 is a piping diagram illustrating the configuration of a refrigeration system. Figure 12 is a schematic diagram illustrating the configuration of a blower.

[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 a motor (10) according to an 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] [Stator] 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 six magnetic poles, with six first magnets (41) arranged at equal intervals in the circumferential direction and six 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. The rotor core (20) is also made of a laminated core. Specifically, the rotor core (20) is made 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 the same along its entire length in the axial direction. In this example, the outer shape of the cross-section 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 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 provided at 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 the rotation axis (Q) as the center, and is the same over the entire axial length of the rotor core (20). The wall surface of the shaft hole (30) is a cylindrical surface with the rotation axis (Q) as the center. A shaft (15) is inserted and fixed in the shaft hole (30).

[0041] <Gap Portion> In the rotor core (20), a first gap portion (31) and a second gap portion (32) are formed for each magnetic pole of the rotor (11). In this example, six first gap portions (31) are arranged at equal intervals in the circumferential direction, and six second gap portions (32) are arranged at equal intervals in the circumferential direction. The second gap portion (32) is arranged radially outside the shaft hole (30). The first gap portion (31) is arranged radially outside the second gap portion (32).

[0042] The first gap portion (31) is formed such that the radially outer side of the first gap portion (31) is open, or the radially outer side of the first gap portion (31) is blocked and the wall surface on the radially outer side of the first gap portion (31) protrudes radially outward.

[0043] In this example, the configuration of the first gap portion (31) is the latter configuration. The wall surface on the radially outer side of the first gap portion (31) is formed in an arc surface shape that protrudes radially outward. The central surface portion in the circumferential direction of the wall surface on the radially inner side of the first gap portion (31) is formed in a planar shape perpendicular to the above-mentioned symmetry axis. Both end surface portions (portions adjacent to the central surface portion in the circumferential direction) in the circumferential direction of the wall surface on the radially inner side of the first gap portion (31) are formed in a planar shape that is inclined with respect to the central surface portion and along the radial direction.

[0044] Further, the first gap portion (31) is arranged not near the shaft hole (30) but near the outer peripheral surface of the rotor core (20). In other words, the shortest distance between the first gap portion (31) and the rotation axis (Q) is longer than half of the shortest distance between the outer peripheral surface of the rotor core (20) and the rotation axis (Q).

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

[0046] 〈Configuration of Rotor Core〉 The rotor core (20) has a base portion (21). Also, the rotor core (20) has a magnetic path portion (22), an arc portion (23), a first bridge (24), and a second bridge (25) for each magnetic pole of the rotor (11).

[0047] 〈Base Portion〉 The base portion (21) is the portion between the shaft hole (30) and the plurality of 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 an arc surface shape that is 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). Also, a protruding portion that protrudes outward in the radial direction is formed between the surface portions adjacent to each other in the circumferential direction.

[0048] 〈Magnetic Path Portion〉 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 outside the magnetic path portion (22). The second gap portion (32) is arranged radially inside the magnetic path portion (22).

[0049] The magnetic path portion (22) is formed to be convex toward the rotation axis (Q). The central surface portion in the circumferential direction of the radially outer wall surface of the magnetic path portion (22) is formed in a planar shape perpendicular to the above-mentioned symmetry axis. The both end surface portions (the surface portions adjacent to the central surface portion in the circumferential direction) in the circumferential direction of the radially outer wall surface of the magnetic path portion (22) are formed in a planar shape that is inclined with respect to the central surface portion and along the radial direction. The radially inner wall surface of the magnetic path portion (22) is formed in an arc surface shape that is convex toward the rotation axis (Q). The magnetic path portion (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 side in the circumferential direction of the first gap (31), is a surface that constitutes a part of the outer 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 (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 (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 section (23) is provided radially outward from the first void section (31) and closes the radially outward side of the first void section (31). Specifically, the radially outward wall surface of the arc section (23) is a surface that constitutes a part of the outer circumferential surface of the rotor core (20) and is formed in the shape of an arc with respect to the axis of rotation (Q). The radially inward wall surface of the arc section (23) is formed in the shape of an arc with respect to the axis of rotation (Q). The radial length of the arc section (23) (the thickness of the arc section (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 part of the base (21), and closes one circumferential end of the second gap section (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). Each part of the motor (10) (especially the magnetic path section (22) and the first air gap section (31)) is formed so as to satisfy these conditions.

[0063] [Fluid Linkage] As shown in Figure 5, the distortion (waveform distortion) of the flux linkage in concentrated windings is greater than that of 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 experience greater changes in 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 the 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 Embodiment and 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 embodiment motor (10). For convenience of explanation, the reference numerals used for the components of the embodiment motor (10) 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 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. Furthermore, in a cross section perpendicular to the axis of rotation (Q), each part of the motor (10) (particularly the first void (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 state where the first magnet (41) and the second magnet (42) are positioned in the first air gap (31) and the second air gap (32), respectively, for the motor of the embodiment (10) and the motor of the comparative example (90). As shown in Figure 7, the distortion of the flux linkage is smaller in the motor of the embodiment (10) and the harmonics included in the flux linkage are smaller in the motor of the comparative example (90). In the example in Figure 7, the distortion rate of the flux linkage in the motor of the comparative example (90) is "11.9%", and the distortion rate of the flux linkage in the motor of the embodiment (10) is "4.6%".

[0073] Figure 8 shows the waveforms of the flux linkage for the motor of the embodiment (10) and the motor of the comparative example (90) 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 of the embodiment (10) has less distortion in the flux linkage and fewer harmonics in the flux linkage than the motor of the comparative example (90). In the example in Figure 8, the distortion rate of the flux linkage in the motor of the comparative example (90) is "4.4%", and the distortion rate of the flux linkage in the motor of the embodiment (10) 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 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 portion (22) extending 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) extending radially inward from the second surface portion (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 void (32). The second void (32) is positioned radially inward from the magnetic path (22).

[0085] In the above configuration, by providing a 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 a high density. This improves the efficiency of the motor (10).

[0092] (Modified 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 embodiment. The other configurations of the modified motor (10) of the embodiment are the same as those 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 form 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 magnets (42a) is rectangular. For example, the magnets (42a) are sintered magnets.

[0095] [Effects of Modified Embodiments] The motor (10) of the modified embodiment can obtain the same effects as the motor (10) of the embodiment. For example, harmonics included in the flux linkage can be suppressed.

[0096] Furthermore, in the motor (10) of the modified embodiment, the second void (32) is composed of a plurality of voids (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] 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 System) 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 back 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) In the above description, the following configuration may be used.

[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 at 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 portion of the radially inner wall surface 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 linear in a cross section perpendicular to the axis of rotation (Q)). (2) The radially inner wall surface of the first void (31) is in the shape of an arc 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) (an arc convex wall surface with respect to the axis of rotation (Q)). (3) The radially inner wall surface of the first void (31) is formed to be concave with respect to the axis of rotation (Q). By making the void (22) in the circumferential direction central portion of the magnetic path (22) in the circumferential direction, the width of the central portion of the magnetic path (22) in the circumferential direction can be increased. This makes it possible to increase the q-axis inductance and increase the reluctance torque. Furthermore, it is possible to improve the design flexibility of the rotor core (20) by securing space for bolt holes and other components.

[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. With this configuration, the arc portion (23) can be prevented 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. Additionally, 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.

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

[0123] 10 Motor 11 Rotor 12 Stator 20 Rotor core 21 Base 22 Magnetic path section 23 Arc section 30 Shaft hole 31 First gap section 32 Second gap section 32a Gap section 41 First magnet 42 Second magnet 42a Magnet 50 Stator core 51 Yoke 52 Teeth 52a First tooth 52b Second tooth 60 Wire 61 Coil L1 First straight line L2 Second straight line L3 Third straight line L4 Fourth straight line θ1 First angle θ2 Second angle

Claims

1. The rotor (11) is rotatable about a rotation axis (Q), and the stator (12) is positioned radially outward from the rotor (11), wherein 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 (Q), and a first void portion (31) formed radially outward from the magnetic path portion (22), the magnetic path portion (22) has a surface portion located on one end side in the circumferential direction of the first void portion (31) and constituting a part of the outer circumferential surface of the rotor core (20), and a first surface portion (22a) which is a surface portion facing radially from the inner circumference of the stator (12), The first void (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) 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 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) has a stator core (50) having a cylindrical yoke (51) and a plurality of teeth (52) arranged in the circumferential direction on the radially inner side of the yoke (51), and an N-phase coil (61) consisting of a conductor (60) wound around the plurality of teeth (52), where N is an integer of 3 or more,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 circumferential direction of the first tooth (52a), which is one of the plurality of teeth (52). A motor in which, when the second angle (θ2) is defined as the angle formed by a third line (L3) hypothetically drawn as a line connecting the center of the motor to the axis of rotation (Q) and a fourth line (L4) hypothetically drawn as a line connecting the center 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), in the circumferential direction, 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).

2. A motor according to claim 1, wherein when the minimum value of the circumferential length of each of the plurality of teeth (52) 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) of the magnetic path portion (22) is the region extending radially inward from the first surface portion (22a) and the radial length is the second length (D2), and the second region (R2) of the magnetic path portion (22) is the region extending radially inward from the second surface portion (22b) and the radial length is the second length (D2), are regions in which no air gap is formed.

3. A motor according to claim 1 or 2, wherein the rotor core (20) has an arc portion (23) provided radially outward from the first gap portion (31) and closing the radially outward side of the first gap portion (31).

4. A motor according to any one of claims 1 to 3, wherein the rotor (11) has a first magnet (41), and the first magnet (41) is arranged in the first gap (31).

5. A motor according to any one of claims 1 to 4, wherein the rotor core (20) has a second gap (32), and the second gap (32) is positioned radially inward from the magnetic path (22).

6. A motor according to claim 5, wherein the rotor (11) has a second magnet (42), and the second magnet (42) is arranged in the second gap (32).

7. A motor according to claim 5 or 6, wherein the second gap (32) is formed to be convex toward the axis of rotation (Q).

8. The motor according to claim 5, wherein the second gap portion (32) is composed of a plurality of gap portions (32a) arranged to be convex toward the rotation axis (Q).

9. A motor according to claim 8, wherein the rotor (11) has a second magnet (42), and the second magnet (42) is arranged in one of the plurality of gaps (32a) that constitute the second gap (32).

10. A motor according to any one of claims 1 to 9, wherein the N-phase coil (61) is composed of the conductor (60) wound around each of the plurality of teeth (52).

11. A compressor comprising any one of the motors of claims 1 to 10.

12. A refrigeration apparatus comprising any one of the motors described in claims 1 to 10.

13. A blower comprising any one of the motors of claims 1 to 10.

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