Rotary electric motor

Abstract

A rotary motor includes: a rotor that is substantially cylindrical or substantially columnar and configured to be rotatable; and a stator that is substantially annular, disposed radially to the rotor, and surrounds a rotation axis of the rotor, the stator having: a coil wound substantially annularly around the rotation axis; and a stator core disposed so as to surround the coil and formed of a powder magnetic core, the stator core having a plurality of cores opposite each other in an axial direction of the stator with the coil interposed therebetween, each of the plurality of cores having: a yoke in contact with or close to another core of the plurality of cores; and one or a plurality of claw poles protruding radially from the yoke toward the rotor, the yoke having at least one yoke face substantially parallel to the axial direction and in contact with or close to the another core at the yoke face.

Description

Technical Field

[0001] This invention relates to rotary electric motors. Background Technology

[0002] A claw-pole motor is known to be constructed from a first core and a second core, both of which are made of powder-pressed iron. The first core includes: a circular plate-shaped connecting base plate; a plurality of claw poles protruding axially from the periphery of the connecting base plate; and a circular yoke portion protruding from the center of the connecting base plate in the same direction as the claw poles. Conversely, the second core includes: a circular plate-shaped connecting base plate that engages with the circular yoke portion of the first core; and a plurality of claw poles protruding from the periphery of the connecting base plate in the opposite direction to the plurality of claw poles of the first core (see, for example, Patent Document 1).

[0003] <Prior art documents>

[0004] <Patent Documents>

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-201299 Summary of the Invention

[0006] <Problem to be solved by this invention>

[0007] When a stator core is formed by pressing powdered magnetic cores, the axial dimensional accuracy is sometimes reduced because the pressing is performed axially on the motor. For example, as in the conventional technology described above, when the first and second cores are axially joined, unexpected gaps sometimes occur at their joint surfaces, or there is a large error in the height of the joint.

[0008] The present invention provides a rotary electric motor capable of suppressing the reduction of axial dimensional accuracy.

[0009] <Methods for solving problems>

[0010] As one aspect of the present invention, a rotary electric motor is provided, comprising:

[0011] The rotor is generally cylindrical or generally cylindrical in shape and configured to rotate freely; and

[0012] The stator, which is generally annular, is arranged radially around the rotor and surrounds the rotor's axis of rotation.

[0013] The above stator has:

[0014] A coil, which is wound into a generally loop shape around the aforementioned axis of rotation; and

[0015] The stator core, which is arranged to surround the aforementioned coil, is formed of a powder-coated magnetic core.

[0016] The stator core described above has a plurality of cores that are axially spaced apart from the coils.

[0017] The aforementioned iron cores each have:

[0018] The magnetic yoke is in contact with or near another iron core among the aforementioned iron cores; and

[0019] One or more claw poles protrude radially from the yoke toward the rotor.

[0020] The claw poles of one of the aforementioned iron cores are formed in a manner that alternates with the claw poles of another iron core that are in contact with or close to the magnetic yoke of the aforementioned iron core in the circumferential direction of the stator.

[0021] The aforementioned yoke has at least one yoke surface that is substantially parallel to the aforementioned axial direction, and the aforementioned yoke surface is in contact with or close to the aforementioned other iron core.

[0022] Based on this configuration, the reduction in axial dimensional accuracy can be suppressed.

[0023] In the aforementioned rotary electric motor,

[0024] The length of the axial direction of the yoke surface can exceed half the length of the axial direction of the yoke.

[0025] According to this configuration, the magnetic flux through the yoke surface can be increased.

[0026] In the aforementioned rotary electric motor,

[0027] One of the aforementioned iron cores may only be in contact with or near the other iron core on the aforementioned yoke surface.

[0028] Based on this configuration, the reduction in axial dimensional accuracy can be further suppressed.

[0029] In the aforementioned rotary electric motor,

[0030] One of the aforementioned iron cores may be in contact or close to the other iron core in the aforementioned circumferential direction at the aforementioned yoke surface.

[0031] This configuration can suppress the reduction in dimensional accuracy in both the axial and circumferential directions.

[0032] In the aforementioned rotary electric motor,

[0033] One of the aforementioned iron cores may be in contact or close to the other iron core in the aforementioned radial direction at the aforementioned yoke surface.

[0034] This configuration can suppress the reduction in axial and radial dimensional accuracy.

[0035] In the aforementioned rotary electric motor,

[0036] In the aforementioned axial top view, the aforementioned yoke surface may be located on the line connecting the circumferential width center of at least one of the plurality of claw magnetic poles and the rotation axis of the aforementioned rotor.

[0037] Based on this configuration, the magnetic resistance of the magnetic circuit through which the magnetic flux passes can be reduced.

[0038] In the aforementioned rotary electric motor,

[0039] The shapes of the aforementioned iron cores can be identical to each other.

[0040] Based on this configuration, the multiple iron cores can be formed using a common metal mold.

[0041] In the aforementioned rotary electric motor,

[0042] The aforementioned magnetic yoke has a plurality of internal teeth that are equally spaced in the aforementioned circumferential direction and have the same width in the aforementioned circumferential direction.

[0043] The circumferential angle between the center of the circumferential width of each of the plurality of claw magnetic poles and the circumferential end of the internal tooth closest to the center of the width among the plurality of internal teeth is set as θ. α The number of the aforementioned claw magnetic poles is set to n, and the circumferential angle between the two ends of each of the aforementioned internal teeth in the aforementioned circumferential direction is set to θ. β When the number of the aforementioned internal teeth is set to N, θ α =180 / (2×n) and θ β =360 / (2×N) is valid.

[0044] Based on this configuration, the multiple iron cores can be formed into the same shape, and thus the multiple iron cores can be formed using a common metal mold.

[0045] In the aforementioned rotary electric motor,

[0046] n can be the same as N or a multiple of N.

[0047] Based on this configuration, the assemblability of multiple iron cores is improved. Attached Figure Description

[0048] Figure 1 This is a perspective view showing an example of a rotary electric motor in the first embodiment.

[0049] Figure 2 This is a perspective view showing an example of the stator in the first embodiment.

[0050] Figure 3This is a perspective view showing an example of a stator unit in the first embodiment.

[0051] Figure 4 This is an exploded perspective view showing an example of a stator unit in the first embodiment.

[0052] Figure 5 This is a top view showing an example of the core in the first embodiment from an axial perspective.

[0053] Figure 6 This is a perspective view showing an example of a stator unit in the second embodiment.

[0054] Figure 7 This is an exploded perspective view showing an example of a stator unit in the second embodiment.

[0055] Figure 8 This is a top view showing an example of the core in the second embodiment from an axial perspective.

[0056] Figure 9 This is a perspective view showing an example of a stator unit in the third embodiment.

[0057] Figure 10 This is a perspective view showing an example of the iron core in the third embodiment.

[0058] Figure 11 This is a perspective view showing an example of a stator unit in the fourth embodiment.

[0059] Figure 12 This is a top view showing an example of an iron core in the fourth embodiment, viewed axially.

[0060] Figure 13 This is a top view showing an example of another core in the fourth embodiment, viewed axially.

[0061] Figure 14 This is a perspective view showing an example of a stator unit in the fifth embodiment.

[0062] Figure 15 This is a perspective view showing an example of the iron core in the fifth embodiment.

[0063] Figure 16 This is a top view showing an example of the core in the fifth embodiment from an axial perspective.

[0064] Figure 17 This is an exploded perspective view showing an example of a stator unit in the sixth embodiment.

[0065] Figure 18 It is shown Figure 14A cross-sectional view of the first configuration example of the magnetic yoke in the arrow view AA.

[0066] Figure 19 It is shown Figure 14 A cross-sectional view of the second configuration example of the magnetic yoke in the arrow view AA. Detailed Implementation

[0067] The implementation method will be described below.

[0068] Figure 1 This is a perspective view showing an example of a rotary electric motor in the first embodiment. Figure 1 The motor 1 shown is an example of a rotary electric motor. Motor 1 is an external rotor type claw pole motor with the rotor 10 arranged radially outward from the stator 13. Motor 1 is used, for example, in air conditioner compressors, fans, etc.

[0069] The motor 1 includes a generally cylindrical rotor 10 configured to rotate freely, and a generally annular stator 13 disposed radially inside the rotor 10 and surrounding the rotation axis AX of the rotor 10.

[0070] The rotor 10 is positioned radially (hereinafter referred to as "radial") outward of the motor 1 relative to the stator 13, configured to rotate about the rotation axis AX. The rotor 10 includes a rotor core 11 and a plurality of (20 in this example) permanent magnets 12.

[0071] The rotor core 11 has, for example, a generally cylindrical shape and is arranged such that the rotation axis AX of the motor 1 is substantially aligned with the axis of the cylindrical shape. The rotor core 11 has a length approximately equal to that of the stator 13 in the axial direction (hereinafter referred to only as the "axial direction") of the motor 1 and is formed of a magnetic material (e.g., steel plate, cast iron, or pressed powder core). The rotor core 11 can be formed as a single component in the axial direction or by combining multiple components (e.g., a number corresponding to the number of stator units described later) stacked in the axial direction.

[0072] Multiple permanent magnets 12 are arranged at equal intervals in the circumferential direction on the inner circumferential surface of the rotor core 11 (20 in this example). The multiple permanent magnets 12 are formed such that they exist between approximately one end and approximately the other end of the rotor core 11 in the axial direction. The permanent magnets 12 are, for example, neodymium sintered magnets or ferromagnetic magnets.

[0073] Multiple permanent magnets 12 are magnetized into different magnetic poles at their radial ends. Two permanent magnets 12 that are circumferentially adjacent to each other are magnetized into different magnetic poles on their radially inner sides facing the stator 13. Therefore, permanent magnets 12 magnetized into N poles on their radially inner sides and permanent magnets 12 magnetized into S poles on their radially inner sides are arranged alternately on the radially outer side of the stator 13.

[0074] The multiple permanent magnets 12 can each be composed of a single magnet component in the axial direction, or they can be composed of multiple magnet components that are divided in the axial direction (e.g., a number corresponding to the number of stator units described later in the axial stack). In this case, the multiple magnet components used to constitute the axially divided permanent magnets 12 are magnetized to the same magnetic poles on the radially inner side facing the stator 13.

[0075] It should be noted that the multiple permanent magnets 12 arranged circumferentially can be replaced with, for example, ring-shaped magnets or plastic magnets with different magnetic poles alternately magnetized circumferentially, or permanent magnets consisting of a single component in the circumferential direction. In this case, the permanent magnet consisting of a single component in the circumferential direction can also consist of a single component in the axial direction, forming a single component as a whole. Furthermore, similar to the case of multiple permanent magnets 12, the permanent magnet consisting of a single component in the circumferential direction can be divided into multiple components in the axial direction. Additionally, if a plastic magnet consisting of a single component in the circumferential direction is used, the rotor core 11 can be omitted. It should be noted that, regardless of whether the permanent magnet consists of multiple components or a single component, it is arranged or magnetized with a predetermined number of poles in the circumferential direction.

[0076] Figure 2 This is a perspective view showing an example of the stator in the first embodiment. Specifically, Figure 2 It was omitted. Figure 1 The figure shows a diagram of rotor 10. Figure 2 The stator 13 shown is disposed radially inside the rotor 10 (rotor core 11 and permanent magnet 12). The stator 13 is a component formed in a generally annular shape around the rotation axis AX of the rotor 10. In this example, the stator 13 includes a plurality of stator units 14-16 stacked axially (three in this example) and a plurality of non-magnetic layers 17, 18 (two in this example).

[0077] The stator 13 has multiple phase (three-phase in this example) stator units 14 to 16 with substantially the same structure. Specifically, the stator 13 has a stator unit 14 corresponding to U, a stator unit 15 corresponding to V, and a stator unit 16 corresponding to W. The multiple stator units 14 to 16 are arranged in a circumferential position offset from each other by 120° in electrical angle.

[0078] It should be noted that the phase of motor 1 (stator 13) is not limited to three phases; it can be single-phase or multi-phase (two-phase or four-phase or more).

[0079] The stator 13 has a non-magnetic layer 17 between axially adjacent stator units 14 and 15, and a non-magnetic layer 18 between axially adjacent stator units 15 and 16. The non-magnetic layer 17 suppresses leakage flux between adjacent stator units 14 and 15 of different phases. The non-magnetic layer 18 suppresses leakage flux between adjacent stator units 15 and 16 of different phases.

[0080] The non-magnetic layer 17 is a UV-phase interleaved member disposed between axially adjacent U-phase stator units 14 and V-phase stator units 15. The non-magnetic layer 17 has, for example, a generally circular plate shape or a generally cylindrical shape having a predetermined thickness in the axial direction, and an insertion hole (not shown) is formed in its central portion for insertion of an insertion member. The same can be true for the non-magnetic layer 18. The non-magnetic layer 18 is a VW-phase interleaved member disposed between axially adjacent V-phase stator units 15 and W-phase stator units 16.

[0081] Figure 3 This is a perspective view showing an example of a stator unit in the first embodiment. Figure 4 This is an exploded perspective view showing an example of a stator unit in the first embodiment. Since the stator units 15 and 16 described above are related to... Figure 3 , 4 The stator unit 14 shown in the figure has a substantially the same structure, so the description of the structure of stator units 15 and 16 is omitted by referring to the description of stator unit 14.

[0082] Stator unit 14 has a coil 19 wound in a generally loop shape around a rotation axis AX, a stator core 9 arranged to surround the coil 19, and an insertion hole 8 for insertion of an insertion member (not shown) (see reference). Figure 3 The stator core 9 is formed from a powder core. By forming it from a powder core, iron losses at high frequencies can be reduced. The stator core 9 has a plurality of cores 20, 40 that are axially opposed to coils 19 in the stator 13.

[0083] Multiple iron cores 20 and 40 are arranged to surround the coil 19. The multiple iron cores 20 and 40 are of the same shape.

[0084] like Figure 4 As shown, the iron core 20 has a magnetic yoke 21, multiple claw magnetic poles 22, and a central hole 23, and the iron core 40 has a magnetic yoke 41, multiple claw magnetic poles 42, and a central hole 43.

[0085] The yokes 21 and 41 have an annular shape when viewed axially and a predetermined thickness in the axial direction. The yoke 21 is in contact with or near another iron core 40, which is different from itself among the plurality of iron cores 20 and 40. The yoke 21 has a generally annular first yoke portion 24 and a second yoke portion 25 that contacts the other iron core 40. The yoke 41 is in contact with or near another iron core 20, which is different from itself among the plurality of iron cores 20 and 40. The yoke 41 has a generally annular first yoke portion 44 and a second yoke portion 45 that contacts the other iron core 20.

[0086] The second yoke portion 25 protrudes a predetermined amount from the inner peripheral surface 24a of the first yoke portion 24 toward the other core 40. In this example, this protrusion includes a plurality of internal teeth 26 (26a, 26b, 26c, 26d) arranged at circumferential intervals. The second yoke portion 45 protrudes a predetermined amount from the inner peripheral surface 44a of the first yoke portion 44 toward the other core 20. In this example, this protrusion includes a plurality of internal teeth 46 (46a, 46b, 46c, 46d) arranged at circumferential intervals.

[0087] Multiple claw poles 22 are circumferentially spaced on the outer peripheral surface 24b of the first yoke portion 24 of the yoke 21. The multiple claw poles 22 protrude radially outward from the outer peripheral surface 24b of the first yoke portion 24 of the yoke 21 toward the rotor 10. Multiple claw poles 42 are circumferentially spaced on the outer peripheral surface 44b of the first yoke portion 44 of the yoke 41. The multiple claw poles 42 protrude radially outward from the outer peripheral surface 44b of the first yoke portion 44 of the yoke 41 toward the rotor 10. Each claw pole 22 includes a claw pole portion 27, and each claw pole 42 includes a claw pole portion 47.

[0088] The claw magnetic pole portion 27 has a predetermined width and protrudes by extending a predetermined length from the outer peripheral surface 24b of the first magnetic yoke portion 24 of the magnetic yoke 21. The claw magnetic pole portion 47 has a predetermined width and protrudes by extending a predetermined length from the outer peripheral surface 44b of the first magnetic yoke portion 44 of the magnetic yoke 41.

[0089] Furthermore, claw pole 22 includes claw pole portion 28, and claw pole 42 includes claw pole portion 48. This ensures that the relative area between the pole surfaces of the claw poles 22 and 42, which are magnetized by the armature current of coil 19, and the rotor 10 is relatively large. Therefore, the torque of motor 1 can be relatively increased, thereby improving the output of motor 1.

[0090] The claw pole portion 28 protrudes from the tip of the claw pole portion 27 in a manner that extends axially for a predetermined length toward the other iron core 40 of the pair of iron cores 20, 40. For example, the claw pole portion 28 is formed with a constant width regardless of the distance from the claw pole portion 27. The claw pole portion 48 protrudes from the tip of the claw pole portion 47 in a manner that extends axially for a predetermined length toward the other iron core 20 of the pair of iron cores 20, 40. For example, the claw pole portion 48 is formed with a constant width regardless of the distance from the claw pole portion 47.

[0091] It should be noted that the claw magnetic poles 28 and 48 can be omitted.

[0092] The center hole 23 is a through hole surrounded by the inner circumferential surfaces of the plurality of internal teeth 26 of the second yoke 25. The center hole 43 is a through hole surrounded by the inner circumferential surfaces of the plurality of internal teeth 46 of the second yoke 45. By assembling the iron cores 20 and 40, the center holes 23 and 43 form the insertion hole 8 (see reference). Figure 3 ).

[0093] Coil 19 is a wire wound into a circular loop when viewed axially. The coil is also referred to as a winding. The two ends of coil 19 are electrically connected to the external terminals of motor 1. The external terminals of motor 1 are electrically connected to a drive unit (e.g., an inverter) that drives motor 1 using power supplied from a power source.

[0094] The coil 19 is axially disposed between a pair of iron cores 20 and 40. The coil 19 is wound in such a way that it has an outer peripheral portion 19a located radially inward of the outer peripheral surfaces 24b and 44b of the first magnetic yoke portions 24 and 44, and an inner peripheral portion 19b located radially outward of the inner peripheral surfaces 24a and 44a of the first magnetic yoke portions 24 and 44.

[0095] Coil 19 contacts at least one of the pair of iron cores 20, 40, thereby improving the heat dissipation effect of coil 19. For example, coil 19 is axially sandwiched between the first yoke 24 and the first yoke 44 while in axial contact with one or both of the first yoke portions 24 and 44. Coil 19 may also contact one or both of the second yoke portions 25 and 45. Coil 19 may contact at least one of the pair of iron cores 20, 40 via a winding tube (not shown).

[0096] The coil 19 can be insulated using known methods such as core casting and winding tubes (winding devices). Insulation methods such as wrapping insulating tape around an air-core winding or molding are also available. The wire used for the coil 19 can be any type of wire, such as round wire, square wire, or Liz wire, but square wire or aligned wound round wire is preferred.

[0097] like Figure 3As shown, a pair of iron cores 20 and 40 are combined in a manner where the claw poles 22 of one iron core 20 and the claw poles 42 of the other iron core 40 are arranged alternately in the circumferential direction. Specifically, the multiple claw poles 22 of one iron core 20 and the claw poles 42 of the other iron core 40 are arranged alternately in the circumferential direction of the stator core 9 (the circumferential direction of the stator 13). It should be noted that it is also possible that the number of claw poles 22 of the iron core 20 and the number of claw poles 42 of the iron core 40 are both one. In this case, the arrangement of one claw pole 22 and one claw pole 42 in a circumferential alternating manner means that one claw pole 42 is located in one circumferential direction of one claw pole 22, and that one claw pole 22 is located in that one circumferential direction of one claw pole 42.

[0098] If an armature current flows through the annular coil 19, the claw pole 22 of one core 20 and the claw pole 42 of the other core 40 are magnetized, each having a different magnetic pole. Thus, in the pair of cores 20 and 40, one claw pole 22 protruding from one core 20 has a different magnetic pole than the other claw pole 42 protruding from the adjacent core 40 in the circumferential direction. Therefore, by the armature current flowing in the coil 19, combinations of N-pole claw pole 22 and S-pole claw pole 42, and combinations of N-pole claw pole 42 and S-pole claw pole 22, alternately occur in the circumference of the stator core 9 (the pair of cores 20 and 40).

[0099] With the pair of iron cores 20 and 40 combined via coil 19, the multiple internal teeth 26 can extend axially from the iron core 40 or not, and the multiple internal teeth 46 can extend axially from the iron core 20 or not. Spacers can be inserted inside the pair of iron cores 20 and 40 to adjust the axial length of the stator iron core 9.

[0100] In a pair of iron cores 20 and 40, the yoke of one iron core has at least one yoke surface that is substantially parallel to the axial direction and is in contact with or near the other iron core. In this example, the yoke 21 of iron core 20 has a yoke surface 29 that is in contact with or near the yoke surface 49 of the yoke 41 of iron core 40, and a yoke surface 30 that is in contact with or near the yoke surface 50 of the yoke 41 of iron core 40.

[0101] The yoke surface 29 is a surface provided on each of the plurality of internal teeth 26 (26a, 26b, 26c, 26d) of the second yoke portion 25, the side facing circumferentially (in Figure 3 , 4 (The middle direction is clockwise). The magnetic yoke surface 30 is a surface provided on each of the plurality of internal teeth 26 (26a, 26b, 26c, 26d) of the second magnetic yoke 25, facing the other side in the circumferential direction (in Figure 3 , 4(The middle direction is counterclockwise). The yoke surface 50 is a surface provided on each of the plurality of internal teeth 46 (46a, 46b, 46c, 46d) of the second yoke portion 45, and its circumferential side (in) Figure 3 , 4 (The middle direction is clockwise). The magnetic yoke surface 49 is a surface provided on each of the plurality of internal teeth 46 (46a, 46b, 46c, 46d) of the second magnetic yoke 45, facing the other side in the circumferential direction (in Figure 3 , 4 (The middle direction is counterclockwise).

[0102] Each of the multiple internal teeth 26 contacts or approaches two internal teeth 46 that are adjacent to each other on either side of it in the circumferential direction. In other words, each of the multiple internal teeth 46 contacts or approaches two internal teeth 26 that are adjacent to each other on either side of it in the circumferential direction. Specifically, the internal tooth 26a of the yoke 21 contacts or approaches the yoke surface 49 of the internal tooth 46a adjacent to it on one side of the circumferential direction on the yoke surface 29, and the yoke surface 30 contacts or approaches the yoke surface 50 of the internal tooth 46d adjacent to it on the other side of the circumferential direction. The same applies to the other internal teeth. Thus, each of the multiple yoke surfaces 29 contacts or approaches a corresponding yoke surface 49 among the multiple yoke surfaces 49, and each of the multiple yoke surfaces 30 contacts or approaches a corresponding yoke surface 50 among the multiple yoke surfaces 50.

[0103] In this example, the yoke 21 of the core 20 has an outer peripheral surface 31 that contacts or approaches the inner peripheral surface 44a of the yoke 41 of the core 40, and the yoke 41 of the core 40 has an outer peripheral surface 51 that contacts or approaches the inner peripheral surface 24a of the yoke 21 of the core 20. Any of the inner peripheral surfaces 24a and 44a, and the outer peripheral surfaces 31 and 51, is a yoke surface that is substantially parallel to the axial direction.

[0104] The outer peripheral surface 31 is a curved surface provided on each of the plurality of internal teeth 26 (26a, 26b, 26c, 26d) of the second magnetic yoke 25, facing radially outward. The outer peripheral surface 51 is a curved surface provided on each of the plurality of internal teeth 46 (46a, 46b, 46c, 46d) of the second magnetic yoke 45, facing radially outward.

[0105] Thus, the motor 1 in the first embodiment has the following configuration: the yoke of one of the iron cores 20 and 40 has at least one yoke surface that is substantially parallel to the axial direction, and this yoke surface is in contact with or close to the other iron core. According to this configuration, by pressing the powder core in the axial direction, the iron cores 20 and 40 can be formed. Even if the dimensional accuracy in the pressing direction deteriorates, the dimensional accuracy of the yoke surface is difficult to decrease because it is substantially parallel to the pressing direction. Therefore, it is possible to suppress the decrease in the axial dimensional accuracy of the stator core 9.

[0106] Furthermore, since the second magnetic yokes 25 and 45 of the cores 20 and 40 are not arranged around the entire circumference, but are composed of multiple internal teeth 26 and 46 with a total circumferential length of approximately half a circumference, the projected area of ​​the cores 20 and 40 in the axial direction is reduced. As a result, the pressure when pressing the powder core can be set to be smaller, thus enabling, for example, miniaturization of the pressing machine.

[0107] Furthermore, since the iron cores 20 and 40 are axially embedded until the yokes 21 and 41 are connected to the coil 19, the iron cores 20 and 40 and the coil 19 can be tightly fitted together, thus improving the heat dissipation of the coil 19 to the iron cores 20 and 40.

[0108] It should be noted that the contact methods between the yoke surface and another iron core can include joining, fitting, bonding, and pressure welding. There are also methods where the yoke surface approaches another iron core while maintaining a small gap that partially separates it from forming a magnetic circuit.

[0109] In the first embodiment, the axial length of the yoke surfaces 29 and 30 exceeds half the axial length of the yoke 21; in this example, they are approximately the same axial length as the yoke 21. In the first embodiment, the axial length of the yoke surfaces 49 and 50 exceeds half the axial length of the yoke 41; in this example, they are approximately the same axial length as the yoke 41. With this configuration, the magnetic flux through the yoke surfaces 29, 30, 49, and 50 can be increased, thereby increasing, for example, the torque of the motor 1.

[0110] In the first embodiment, the core 20 contacts or approaches the core 40 only on the yoke surfaces (yoke surfaces 29, 30 and outer peripheral surface 31), and the core 40 contacts or approaches the core 20 only on the yoke surfaces (yoke surfaces 49, 50 and outer peripheral surface 51). With this configuration, even when each core 20, 40 is formed by axially pressing the powder core, the dimensional accuracy of the yoke surface is difficult to reduce because it is approximately parallel to the pressing direction. Therefore, it is possible to further suppress the reduction in the axial dimensional accuracy of the stator core 9.

[0111] In the first embodiment, core 20 is in contact or close to core 40 on yoke surfaces 29 and 30 in the circumferential direction, and core 40 is in contact or close to core 20 on yoke surfaces 49 and 50 in the circumferential direction. With this configuration, even when the powder cores are pressed axially to form individual cores 20 and 40, the dimensional accuracy of the yoke surfaces is difficult to reduce because they are approximately parallel to the pressing direction. Therefore, it is possible to suppress the reduction of dimensional accuracy in both the axial and circumferential directions of the stator core 9.

[0112] In the first embodiment, core 20 is in radial contact or close proximity to core 40 on the yoke surface (outer peripheral surface 31 in this example), and core 40 is in radial contact or close proximity to core 20 on the yoke surface (outer peripheral surface 51 in this example). With this configuration, even when the powder cores are pressed axially to form individual cores 20 and 40, the dimensional accuracy of the yoke surface is difficult to reduce because it is approximately parallel to the pressing direction. Therefore, it is possible to suppress the reduction in axial and radial dimensional accuracy of the stator core 9.

[0113] In the first embodiment, the multiple iron cores 20, 40 have identical shapes. With this configuration, the multiple iron cores 20, 40 can be formed using a common metal mold. Therefore, for example, the manufacturing cost of the stator iron core 9 can be reduced.

[0114] Figure 5 This is a top view showing an example of the iron core in the first embodiment, viewed axially. Because the aforementioned iron core 20 is... Figure 5 The iron core 40 shown has a substantially the same structure, so the description of the structure of the iron core 20 is omitted by referring to the description of the iron core 40.

[0115] The yoke 41 of the iron core 40 has a plurality of internal teeth 46 (46a, 46b, 46c, 46d) arranged at equal intervals in the circumferential direction and having equal width in the circumferential direction, and a plurality of claw poles 42 arranged at equal intervals in the circumferential direction and having equal width in the circumferential direction.

[0116] Angle θ α This refers to the circumferential angle θ between the circumferential width center 52 of each of the plurality of claw magnetic poles 42 and the circumferential end (in this example, the yoke surface 49) of the internal tooth 46 closest to the width center 52 among the plurality of internal teeth 46. More specifically, in axial view, the angle θ α Let L1 be the central angle between the line L1 connecting the width center 52 of a claw magnetic pole and the rotation axis AX of the rotor 10 and the line L2 connecting the circumferential end of the internal tooth closest to the width center 52 (in this example, the yoke surface 49) and the rotation axis AX of the rotor 10.

[0117] Angle θ β This indicates the circumferential angle between the respective circumferential ends (in this example, the magnetic yoke surfaces 49 and 50) of the plurality of internal teeth 46. More specifically, in axial view, the angle θ β This represents the central angle between line L2, which connects one circumferential end of an internal tooth (in this example, the magnetic yoke surface 49) and the rotation axis AX of the rotor 10, and line L3, which connects the other circumferential end of the internal tooth (in this example, the magnetic yoke surface 50) and the rotation axis AX of the rotor 10.

[0118] When the number of multiple claw poles 42 is set to n and the number of multiple internal teeth 46 is set to N, if the following equations 1 and 2 are true, multiple iron cores 20 and 40 can be formed into the same shape, thereby enabling the multiple iron cores 20 and 40 to be formed using a common metal mold. Therefore, for example, the manufacturing cost of stator iron core 9 can be reduced.

[0119] θ α =180 / (2×n)…Equation 1

[0120] θ β =360 / (2×N)…Equation 2

[0121] exist Figure 5 In the example shown, since n = 10 and N = 4, based on equations 1 and 2 above, by setting "θ"... α =9°, θ β =45°”, which can form multiple iron cores 20 and 40 into the same shape.

[0122] Figure 6 This is a perspective view showing an example of a stator unit in the second embodiment. Figure 7 This is an exploded perspective view showing an example of the stator unit in the second embodiment. By referring to the above description, descriptions of configurations and effects identical to those in the above embodiment are omitted or simplified.

[0123] exist Figure 6 , 7 In this embodiment, the stator core 9 has multiple cores 20A and 40A axially opposite to the coils 19 in the stator 13. For stator unit 14A, the number and shape of the multiple claw poles 22 and 42 differ from those in the stator unit 14 of the first embodiment. Claw pole portion 28 has a conical shape whose width narrows axially as it moves away from claw pole portion 27. Claw pole portion 48 has a conical shape whose width narrows axially as it moves away from claw pole portion 47.

[0124] Figure 8 This is a top view showing an example of the core in the second embodiment, viewed axially. Since the aforementioned core 20A is... Figure 8 The structure of the iron core 40A shown is roughly the same, so the description of the structure of the iron core 20A is omitted by referring to the description of the iron core 40A.

[0125] exist Figure 8 In the example shown, since the number of claw magnetic poles 42, n, is 8, and the number of internal teeth 46, N, is 4, therefore, by setting "θ α =11.25°, θ β =45°”, thus enabling multiple iron cores 20A and 40A to be formed into the same shape.

[0126] Furthermore, since the number of claw poles 42 (n=8) is a multiple of the number of internal teeth 46 (N=4), for example, the cores 20A and 40A can be assembled regardless of whether the internal tooth 26a is positioned between internal teeth 46d and 46a or between internal teeth 46a and 46b. Therefore, the assemblability of the cores 20A and 40A is improved.

[0127] Figure 9 This is a perspective view showing an example of a stator unit in the third embodiment. By referring to the above description, descriptions of configurations and effects identical to those in the above embodiments are omitted or simplified.

[0128] exist Figure 9 In this embodiment, the stator core 9 has a plurality of cores 20B, 40B that are axially opposed to each other by coils 19 in the stator 13. For stator unit 14B, the shape of the plurality of internal teeth 26, 46 is different from that of stator unit 14A in the second embodiment.

[0129] Figure 10 This is a perspective view showing an example of the iron core in the third embodiment. By referring to the above description, descriptions of the same configurations and effects as in the above embodiment are omitted or simplified. Since the iron core 20B described above is similar to... Figure 10 Since the core 40B shown has a similar structure, the description of the structure of core 20B is omitted by referring to the description of core 40B.

[0130] The multiple internal teeth 46 (46a, 46b, 46c, 46d) each have a conical shape whose width narrows as it moves axially away from the inner peripheral surface 44a of the first yoke 44. By having such a conical shape, the multiple internal teeth 26, 46 facilitate the axial assembly of the iron cores 20B and 40B.

[0131] exist Figure 10 In the example shown, since the number of claw magnetic poles 42, n, is 8, and the number of internal teeth 46, N, is 4, therefore, by setting "θ α =11.25°, θ β =45°”, which enables multiple iron cores 20B and 40B to be formed into the same shape.

[0132] Figure 11 This is a perspective view showing an example of a stator unit in the fourth embodiment. By referring to the above description, descriptions of configurations and effects identical to those in the above embodiments are omitted or simplified.

[0133] exist Figure 11In the stator core 9, there are a plurality of cores 20C, 40C opposite each other on the axial side of the stator 13 with respect to the coils 19. The stator unit 14C differs from the stator unit 14A in the second embodiment in that a pair of cores (cores 20C, 40C) are not identical in shape.

[0134] Figure 12 A top view showing an example of a core in the fourth embodiment is presented in axial view. Figure 13 This is a top view showing an example of another core in the fourth embodiment from an axial perspective. Figure 12 Showing core 20C, Figure 13 The iron core 40C is shown.

[0135] exist Figure 12 In the middle, angle θ α1 This refers to the circumferential angle θ between the circumferential width center 52 of each of the plurality of claw magnetic poles 22 and the circumferential end (in this example, the yoke surface 30) of the plurality of internal teeth 26 closest to the width center 52. More specifically, in axial view, the angle θ α1 Let L1 be the central angle between the line L1 connecting the width center 52 of a claw magnetic pole and the rotation axis AX of the rotor 10 and the line L2 connecting the circumferential end of the internal tooth closest to the width center 52 (in this example, the yoke surface 30) and the rotation axis AX of the rotor 10. Figure 12 An example is shown for θ α1 =0°.

[0136] exist Figure 12 In the middle, angle θ β This represents the circumferential angle between the respective circumferential ends (in this example, the magnetic yoke surfaces 29 and 30) of the plurality of internal teeth 26. More specifically, in axial view, the angle θ β This represents the central angle between line L2, which connects one circumferential end of an internal tooth (in this example, the magnetic yoke surface 30) and the rotation axis AX of the rotor 10, and line L3, which connects the other circumferential end of the internal tooth (in this example, the magnetic yoke surface 29) and the rotation axis AX of the rotor 10.

[0137] exist Figure 13 In the middle, angle θ α2 This refers to the circumferential angle θ between the circumferential width center 52 of each of the plurality of claw magnetic poles 42 and the circumferential end (in this example, the yoke surface 49) of the inner tooth 46 closest to the width center 52 among the plurality of inner teeth 46. More specifically, in axial view, the angle θ α2Let L1 be the central angle between the line L1 connecting the width center 52 of a claw magnetic pole and the rotation axis AX of the rotor 10 and the line L2 connecting the circumferential end of the internal tooth closest to the width center 52 (in this example, the yoke surface 49) and the rotation axis AX of the rotor 10.

[0138] exist Figure 13 In the middle, angle θ β This represents the circumferential angle between the respective circumferential ends (in this example, the yoke surfaces 49 and 50) of the plurality of internal teeth 46. More specifically, in axial view, the angle θ β This represents the central angle between line L2, which connects one circumferential end of an internal tooth (in this example, the magnetic yoke surface 49) and the rotation axis AX of the rotor 10, and line L3, which connects the other circumferential end of the internal tooth (in this example, the magnetic yoke surface 50) and the rotation axis AX of the rotor 10.

[0139] In combination θ α1 and θ α2 In different core configurations, θ is determined by a reference core 20C. α1 and θ β The value is used to calculate θ for core 40C relative to core 20C. α2 The value of is calculated using the following formula 3.

[0140] θ α2 =θ α1 / 2+θ β / 2…Form 3

[0141] However, this applies only to cores 20C and 40C, where the number and shape of the internal teeth are the same.

[0142] For example, in the case of the number of internal teeth (N=4), based on Equation 2 above, since "θ β =45°”, therefore based on Equation 3, and θ α1 =30° core 20C relative to core 40C θ α2 It is 37.5°. For example, in the case of the number of internal teeth (N=4), since it is based on Equation 2 above, it is "θ β =45°”, therefore based on Equation 3, and θ α1 =0° iron core 20C relative to iron core 40C θ α2 It is 22.5°.

[0143] exist Figure 12In a top view along the axial direction, the yoke surface 30 lies on line L1 connecting the circumferential width center 52 of at least one of the claw poles 22 and the rotation axis AX of the rotor 10. The magnetic flux entering from the claw poles 22 toward the rotation axis AX is divided into the inner tooth 26a side and the inner tooth 46d side (see reference). Figure 13 Therefore, if the yoke surface 30 is located above line L1, the magnetic flux through the yoke surface 30 is reduced. Thus, the magnetic reluctance of the magnetic circuit through which the magnetic flux passes can be reduced, thereby increasing the torque of the motor 1.

[0144] Figure 14 This is a perspective view showing an example of the stator unit in the fifth embodiment. By referring to the above description, descriptions of configurations and effects identical to those in the above embodiments are omitted or simplified.

[0145] exist Figure 14 In this embodiment, the stator core 9 has a plurality of cores 20D and 40D that are axially opposite to the coils 19 in the stator 13. The stator unit 14D differs from the stator unit 14A in that the circumferential widths of the plurality of internal teeth 26 and the circumferential widths of the plurality of internal teeth 46 are not the same.

[0146] Figure 15 This is a perspective view showing an example of the iron core in the fifth embodiment. Figure 16 This is a top view showing an example of the core in the fifth embodiment from an axial perspective. By referring to the above description, descriptions of the same configurations and effects as in the above embodiments are omitted or simplified. Since the core 20D described above is similar to... Figure 15 , 16 Since the structure of the iron core 40D shown is roughly the same, the description of the structure of the iron core 20D is omitted by referring to the description of the iron core 40D.

[0147] Regardless of their distance from the inner circumferential surface 44a of the first magnetic yoke 44, the internal teeth 46a, 46b, and 46c each protrude axially with a constant bending width (more specifically, arc length). The bending widths of the internal teeth 46a, 46b, and 46c are different from each other.

[0148] Figure 17 This is an exploded perspective view showing an example of the stator unit in the sixth embodiment. By referring to the above description, configurations and effects identical to those in the above embodiments are omitted or simplified.

[0149] exist Figure 17 In this embodiment, the stator core 9 has multiple cores 20E and 40E that are axially opposite to the coils 19 in the stator 13. For stator unit 14E, the shapes of the yokes 21 and 41 are different from those of stator unit 14A in the second embodiment.

[0150] Figure 17 The illustrated yoke 21 has an annular shape when viewed axially and a predetermined thickness in the axial direction. The yoke 21 has a generally annular first yoke portion 24 and a second yoke portion 25 that contacts another iron core 40E. Figure 17 In the example shown, the first yoke portion 24 is the outer peripheral portion of the generally annular yoke 21, and the second yoke portion 25 is the inner peripheral portion of the generally annular yoke 21.

[0151] Figure 17 The illustrated yoke 41 has an annular shape when viewed axially and a predetermined thickness in the axial direction. The yoke 41 has a generally annular first yoke portion 44 and a second yoke portion 45 that contacts another iron core 20E. Figure 17 In the example shown, the first yoke portion 44 is a generally annular portion of the yoke 41, and the second yoke portion 45 is a cylindrical portion that protrudes from the first yoke portion 44 toward the other iron core 20E by a predetermined amount. The outer surface of the cylindrical second yoke portion 45 is in contact with or close to the second yoke portion 25 (the inner circumferential portion of the generally annular yoke 21).

[0152] Figure 18 It is shown Figure 14 The cross-sectional view of the first configuration example of the magnetic yoke in the arrow view AA illustrates the way in which the second magnetic yoke portion 45 is integrally formed with the first magnetic yoke portion 44. Figure 19 It is shown Figure 14 The cross-sectional view of the second configuration example of the magnetic yoke in the arrow view AA illustrates an example where the second magnetic yoke portion 45 and the first magnetic yoke portion 44 are formed separately. Similarly, the first magnetic yoke portion 24 and the second magnetic yoke portion 25 can also be formed integrally or separately. For Figure 14 In other embodiments, the first magnetic yoke and the second magnetic yoke may be integrally formed or formed separately.

[0153] The above describes the embodiments, but it should be understood that various changes can be made to the methods and details, not exceeding the spirit and scope of the claims. Various modifications and improvements, such as combinations, substitutions, etc., with some or all of the other embodiments are possible.

[0154] For example, in the case of axially opposing surfaces in the yoke, it is preferable that the axially opposing surfaces do not contact each other, or that the distance between the axially opposing surfaces is set to be relatively long compared to the distance between yoke surfaces that are approximately parallel in the axial direction. Thus, even if the axial dimensional error is large, it can be absorbed.

[0155] For example, in the above embodiment, the motor 1 is an outer rotor type claw pole motor with the rotor 10 arranged radially outside the stator 13. However, the rotary electric motor of the present invention can also be applied to an inner rotor type claw pole motor with the rotor arranged radially inside the stator. In the case of the inner rotor type, the rotary electric motor includes a generally cylindrical rotor configured to rotate freely, and a generally annular stator arranged radially outside the rotor and surrounding the rotation axis of the rotor.

[0156] This international application claims priority to Japanese Patent Application No. 2020-083123, filed on May 11, 2020, and the entire contents of Japanese Patent Application No. 2020-083123 are incorporated herein by reference.

[0157] Explanation of reference numerals in the attached figures

[0158] 1. Motor

[0159] 8 Insertion Holes

[0160] 9. Stator core

[0161] 10 rotors

[0162] 11 Rotor core

[0163] 12 permanent magnets

[0164] 13 Stator

[0165] Stator units 14-16

[0166] 17,18 Non-magnetic layers

[0167] 19 coils

[0168] 19a Peripheral part

[0169] 19b Inner Peripheral Section

[0170] 20, 40 Iron Heart

[0171] Magnetic yokes 21 and 41

[0172] 22, 42 claw magnetic poles

[0173] 23, 43 center holes

[0174] 24, 44 First Magnetic Yoke

[0175] Inner circumferential surfaces of 24a and 44a

[0176] 24b, 44b outer peripheral surfaces

[0177] 25, 45 Second magnetic yoke section

[0178] 26a, 26b, 26c, 26d, 46a, 46b, 46c, 46d internal teeth

[0179] 27, 28, 47, 48 Claw magnetic poles

[0180] Magnetic yoke surfaces 29, 30, 49, 50

[0181] 31, 51 outer peripheral surfaces

[0182] 52 Width Center

[0183] AX Rotation Axis

[0184] L1, L2 lines

Claims

1. A rotary electric motor comprising: a rotor which is cylindrical or columnar and configured to be rotatable; and a stator which is annular, the stator being disposed radially outward of the rotor and surrounding an axis of rotation of the rotor, the stator having: a coil wound annularly around the axis of rotation; and a stator core disposed so as to surround the coil and formed of a powder magnetic core, the stator core having a plurality of cores opposite each other in an axial direction of the stator with the coil interposed therebetween, each of the plurality of cores having: a yoke in contact with another core of the plurality of cores; and one or more claw poles protruding radially outward from the yoke toward the rotor, the one or more claw poles of one core of the plurality of cores being formed in a manner in which claw poles of the other core are alternately arranged in a circumferential direction of the stator in contact with the yoke of the one core, the yoke having at least one yoke face parallel to the axial direction, the yoke face of the one core being in contact with the other core in the circumferential direction.

2. The rotary electric motor according to claim 1, wherein a length of the yoke face in the axial direction exceeds half a length of the yoke in the axial direction.

3. The rotary electric motor according to claim 1, wherein the one core is in contact with the other core only at the yoke face.

4. The rotary electric motor according to claim 1, wherein the one core is in contact with the other core at the yoke face in the radial direction.

5. The rotary electric motor according to claim 1, wherein in a plan view in the axial direction, the yoke face is positioned above a line connecting a center of a width of the circumferential direction of at least one of the plurality of claw poles and the axis of rotation of the rotor.

6. The rotary electric motor according to claim 1, wherein the plurality of cores are identical in shape to each other.

7. The rotary electric motor according to claim 1, wherein the yoke has a plurality of inner teeth disposed at equal intervals in the circumferential direction and having equal widths in the circumferential direction, an angle in the circumferential direction between a center of a width of the circumferential direction of each of the plurality of claw poles and an end of the circumferential direction of an inner tooth of the plurality of inner teeth closest to the center of the width is set to θa, a number of the plurality of claw poles is set to n, an angle in the circumferential direction between the two ends of the circumferential direction of each of the plurality of inner teeth is set to θβ, a number of the plurality of inner teeth is set to N, θa = 180 / (2 x n) and θβ = 360 / (2 x N) hold.

8. The rotary electric motor according to claim 7, wherein n is equal to or a multiple of N. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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