Rotating electrical machine

Abstract

A rotary electric machine includes a substantially cylindrical or columnar rotor configured to be rotatable, and a substantially annular stator disposed in a radial direction of the rotor and surrounding a rotation axis of the rotor. The stator has a plurality of stator units stacked in an axial direction of the rotor. Each of the stator units has a winding wound in a substantially annular shape around the rotation axis, a stator core disposed so as to surround the winding, and one or more claw poles protruding in the radial direction of the rotor from both ends in the axial direction of the stator core toward the rotor. The rotor has a magnet facing at least a portion of any of the claw poles of the stator in the radial direction at a predetermined rotation position. At least one of magnet end portions in the axial direction of the magnet protrudes in the axial direction further than all of the claw poles of the stator.

Description

Technical Field

[0001] This disclosure relates to a rotary electric motor (electric motor). Background Technology

[0002] A known motor comprises: a stator consisting of an A-phase stator section and a B-phase stator section arranged axially, wherein the A-phase stator section has a plurality of claw-shaped magnetic poles arranged at equal angular intervals, and the B-phase stator section has a plurality of claw-shaped magnetic poles arranged at equal angular intervals; and a rotor having permanent magnets facing (opposite to) the claw-shaped magnetic poles of the A-phase and B-phase stator sections (see, for example, Patent Document 1).

[0003] [Cited Documents]

[0004] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-147811 Summary of the Invention

[0006] [Technical problem to be solved]

[0007] In the case of a rotating motor in which multiple stator units are stacked along the rotor axis, the torque of the rotating motor will decrease.

[0008] This disclosure provides a rotating electric motor capable of suppressing torque reduction.

[0009] [Technical Solution]

[0010] As one aspect of this disclosure, a rotary motor is provided.

[0011] It comprises: a rotor, which is generally cylindrical or generally cylindrical and configured to rotate freely; and a stator, which is generally annular and arranged radially along the rotor and about the rotor's axis of rotation.

[0012] The stator has multiple stator units stacked along the axial direction of the rotor.

[0013] The plurality of stator units each have:

[0014] The winding is arranged in a generally loop shape around the axis of rotation;

[0015] The stator core is arranged to surround the windings; and

[0016] One or more claw poles protrude radially from two ends of the stator core toward the rotor.

[0017] The claw poles protruding from one of the two ends are formed to alternate with the claw poles protruding from the other of the two ends in the circumferential direction of the stator.

[0018] The rotor has a magnet that is positioned radially opposite at least a portion of any of the claw poles of the stator at a predetermined rotational position.

[0019] At least one of the magnet ends of the magnet in the axial direction protrudes from all of the claw poles of the stator along the axial direction.

[0020] Based on this configuration, torque reduction can be suppressed.

[0021] In the aforementioned rotating motors,

[0022] The ends of the magnets on both sides of the axial direction may also protrude along the axial direction from all the claw poles of the stator.

[0023] Based on this configuration, torque reduction can be further suppressed.

[0024] In the aforementioned rotating motors,

[0025] The end of the magnet protrudes along the axial direction from the claw pole of the outer stator unit located on the outer side of the plurality of stator units, thereby reducing the difference between the interlinkage flux of the winding of the outer stator unit and the interlinkage flux of the winding of the inner stator unit located on the inner side of the plurality of stator units.

[0026] According to this configuration, the torque imbalance between the outer stator unit and the inner stator unit can be reduced.

[0027] In the aforementioned rotating motors,

[0028] The plurality of stator units are configured such that adjacent stator units are spaced apart.

[0029] A portion of the magnet may be directed toward the interval in the radial direction.

[0030] Based on this configuration, the reduction in torque can be further suppressed.

[0031] In the aforementioned rotating motors,

[0032] A non-magnetic element is provided at the interval.

[0033] Based on this configuration, leakage flux between adjacent stator units can be suppressed by using non-magnetic materials, thus further suppressing the reduction in torque.

[0034] In the aforementioned rotating motors,

[0035] The magnet may be a single magnetic component.

[0036] According to this configuration, the number of magnet components in the magnet can be reduced, thus improving the assemblability of the magnet to the rotor core.

[0037] In the aforementioned rotating motors,

[0038] The magnet includes a plurality of magnet components arranged along the axial direction.

[0039] The adjacent magnet components in the plurality of magnet components may be radially aligned with the spacing between adjacent stator units in the plurality of stator units.

[0040] Based on this configuration, the reduction in torque can be further suppressed. Attached Figure Description

[0041] Figure 1 This is a perspective view (perspective view) showing an example of the rotary motor in the first embodiment.

[0042] Figure 2 This is a perspective view showing an example of the stator in the first embodiment.

[0043] Figure 3 This is a perspective view showing an example of the stator unit in the first embodiment.

[0044] Figure 4 This is an exploded perspective view showing an example of the stator unit in the first embodiment.

[0045] Figure 5 This is a schematic diagram illustrating an example of an unbalanced state in which the magnetic flux linked to the windings of multiple stator units stacked along the rotor axis becomes unbalanced.

[0046] Figure 6 This is a partial cross-sectional view showing a first configuration example of the rotary electric motor in the first embodiment.

[0047] Figure 7 This is a partial cross-sectional view showing a second configuration example of the rotary electric motor in the first embodiment.

[0048] Figure 8 This is a partial cross-sectional view showing a third configuration example of the rotary electric motor in the first embodiment.

[0049] Figure 9 This is a partial cross-sectional view showing a fourth configuration example of the rotary electric motor in the first embodiment.

[0050] Figure 10 This is a partial cross-sectional view showing a fifth configuration example of the rotary electric motor in the first embodiment.

[0051] Figure 11 This is a partial cross-sectional view showing a sixth configuration example of the rotary electric motor in the first embodiment.

[0052] Figure 12 This is a partial cross-sectional view showing a seventh configuration example of the rotary electric motor in the first embodiment. Detailed Implementation

[0053] The implementation method is described below.

[0054] Figure 1 This is a perspective view showing an example of the rotary motor in the first embodiment. Figure 1 The electric motor 1 shown is an example of a rotating electric motor. Electric motor 1 is an external rotor type claw pole motor with the rotor 10 arranged radially outside the stator 13. Electric motor 1 can be installed, for example, in the compressor or fan of an air conditioner.

[0055] The electric 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. The rotor 10 is longer than the stator 13 in the axial direction (referred to as "axial") of the electric motor 1.

[0056] The rotor 10 is arranged relative to the stator 13 on the outer side of the motor 1 in the radial direction (referred to as "radial") and is 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.

[0057] The rotor core 11 has, for example, a generally cylindrical shape and is configured such that the rotation axis AX of the motor 1 is substantially aligned with the axis of the cylindrical shape. The rotor core 11 is longer than the stator 13 in the axial direction and is formed of a magnetic material (e.g., steel plate, cast iron, pressed powder core, etc.). The rotor core 11 can be formed by a single component in the axial direction or by a combination of multiple components stacked along the axial direction (e.g., a number corresponding to the number of stator units described later).

[0058] Multiple permanent magnets 12 are arranged at equal intervals (20 in this example) along the circumferential direction on the inner circumferential surface of the rotor core 11. The multiple permanent magnets 12 are formed such that they are located approximately from one end to approximately the other end of the rotor core 11 in the axial direction. The permanent magnets 12 are, for example, neodymium sintered magnets and ferromagnetic magnets.

[0059] Multiple permanent magnets 12 are magnetized into different magnetic poles at their radial ends. Two permanent magnets 12 that are circumferentially adjacent among the multiple permanent magnets 12 are magnetized into different magnetic poles on their radially inner sides facing the stator 13. Therefore, on the radially outer side of the stator 13, permanent magnets 12 with their radially inner sides magnetized into N poles and permanent magnets 12 with their radially inner sides magnetized into S poles can be alternately arranged circumferentially.

[0060] 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 along the axial direction (e.g., a number corresponding to the number of stator units stacked along the axial direction, as described later). In this case, the multiple magnet components used to constitute the permanent magnets 12 divided along the axial direction are all magnetized to the same magnetic pole on their radially inner side facing the stator 13.

[0061] It should be noted that, for example, the multiple permanent magnets 12 arranged circumferentially can be replaced with, for example, a ring-shaped magnet, a plastic magnet, or other permanent magnets that are alternately magnetized to different magnetic poles circumferentially, and are composed of a single component in the circumferential direction. In this case, the permanent magnet composed of a single component in the circumferential direction can also be composed of a single component in the axial direction; that is, it can be composed of a single component as a whole. Furthermore, the permanent magnet composed of a single component in the circumferential direction, like the case of multiple permanent magnets 12, can also be divided into multiple components in the axial direction. In addition, when a plastic magnet composed 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 is composed of multiple components or a single component, it is magnetized or arranged with a predetermined number of poles in the circumferential direction.

[0062] 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 diagram shows the rotor 10. Figure 2 The stator 13 shown is arranged radially inside the rotor 10 (rotor core 11 and permanent magnet 12). The stator 13 is a generally annular component formed around the rotation axis AX of the rotor 10. In this example, the stator 13 includes a plurality of (three in this example) stator units 14-16 stacked axially and a plurality of (two in this example) non-magnetic layers 17, 18.

[0063] The stator 13 has multiple stator units 14 to 16 with substantially the same structure (three phases in this example). 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 such that their circumferential positions are offset from each other by an electrical angle of 120°.

[0064] It should be noted that the number of phases of motor 1 (stator 13) is not limited to 3 phases, but can also be 2 phases or more than 4 phases.

[0065] 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. The non-magnetic layers 17 and 18 function as spacers between adjacent phases.

[0066] The non-magnetic layer 17 is a UV-phase interphase component (i.e., a UV-phase interphase component) disposed between axially adjacent U-phase stator units 14 and V-phase stator units 15. The non-magnetic layer 17 is, for example, a generally circular plate or generally cylindrical shape having a predetermined thickness along the axial direction, with an insertion hole (not shown) formed at its center for insertion of an insertion component. The non-magnetic layer 18 may be the same. The non-magnetic layer 18 is a VW-phase interphase component disposed between axially adjacent V-phase stator units 15 and W-phase stator units 16.

[0067] Figure 3 This is a perspective view of an example of the stator unit in the first embodiment. Figure 4 This is an exploded perspective view of an example of the stator unit in the first embodiment. The structure of the stator units 15 and 16 described above is similar to... Figure 3 , 4 Since the stator unit 14 shown is largely the same, the description of the structure of stator units 15 and 16 is omitted by referring to the description of stator unit 14.

[0068] Stator unit 14 has a winding 19 wound into a generally loop shape around a rotation axis AX, a stator core 9 arranged around the winding 19, and an insertion hole 8 for inserting an insertion member (not shown) (see Figure 3 The stator core 9 is formed, for example, by a powder core. By forming the stator core 9 by a powder core, iron loss at high frequencies can be reduced. The stator core 9 has a plurality of magnetic cores 20, 40 facing each other and sandwiching the winding 19 along the axial direction of the stator 13.

[0069] Multiple magnetic cores (iron cores) 20, 40 are arranged around the winding 19. The multiple magnetic cores 20, 40 have the same shape as each other.

[0070] like Figure 4 As shown, the magnetic core 20 has a yoke 21, multiple claw poles 22, and a central hole 23, and the magnetic core 40 has a yoke 41, multiple claw poles 42, and a central hole 43.

[0071] The magnetic yokes 21 and 41 have an annular shape when viewed axially and have a predetermined thickness along the axial direction. The magnetic yoke 21 is in contact with or near another magnetic core 40, which is different from its own core 20, among the plurality of magnetic cores 20 and 40. The magnetic yoke 21 has a generally annular first yoke portion 24 and a second yoke portion 25 that contacts the other magnetic core 40. The magnetic yoke 41 is in contact with or near another magnetic core 20, which is different from its own core 40, among the plurality of magnetic cores 20 and 40. The magnetic yoke 41 has a generally annular first yoke portion 44 and a second yoke portion 45 that contacts the other magnetic core 20.

[0072] The first yoke 24 is an example of one of the two axial ends of the stator core 9. The first yoke 44 is an example of the other axial end of the stator core 9.

[0073] The second yoke 25 protrudes from the inner peripheral surface 24a of the first yoke 24 toward another magnetic core 40 by a predetermined amount. In this example, the second yoke 25 is a portion including a plurality of internal teeth 26 (26a, 26b, 26c, 26d) arranged at circumferential intervals. The second yoke 45 protrudes from the inner peripheral surface 44a of the first yoke 44 toward another magnetic core 20 by a predetermined amount. In this example, the second yoke 45 is a portion including a plurality of internal teeth 46 (46a, 46b, 46c, 46d) arranged at circumferential intervals.

[0074] Multiple claw poles 22 are arranged at equal intervals along the circumferential direction 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 arranged at equal intervals along the circumferential direction 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.

[0075] 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 yoke portion 24 of the 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 yoke portion 44 of the yoke 41.

[0076] Furthermore, claw pole 22 includes claw pole portion 28, and claw pole 42 includes claw pole portion 48. Accordingly, the relative area between the pole surfaces of the claw poles 22 and 42, which are magnetized by the armature current of the winding 19, and the rotor 10 can be ensured to be relatively large. Therefore, the torque of the motor 1 can be relatively increased, thereby improving the output of the motor 1.

[0077] The claw pole portion 28 protrudes axially from the front end of the claw pole portion 27 toward the other magnetic core 40 of the pair of magnetic cores 20, 40 by a predetermined length. For example, the claw pole portion 28 is formed such that its width is constant regardless of the distance from the claw pole portion 27. The claw pole portion 48 protrudes axially from the front end of the claw pole portion 47 toward the other magnetic core 20 of the pair of magnetic cores 20, 40 by a predetermined length. For example, the claw pole portion 48 is formed such that its width is constant regardless of the distance from the claw pole portion 47. It should be noted that the claw pole portion 28 may have a tapered shape in which its width gradually narrows as it separates axially from the claw pole portion 27, and the claw pole portion 48 may have a tapered shape in which its width gradually narrows as it separates axially from the claw pole portion 47.

[0078] It should be noted that the claw magnetic poles 28 and 48 can also be omitted.

[0079] The central hole 23 is a through hole formed by the inner peripheral surfaces of the plurality of internal teeth 26 of the second yoke 25. The central hole 43 is a through hole formed by the inner peripheral surfaces of the plurality of internal teeth 46 of the second yoke 45. By combining the magnetic cores 20 and 40, the central holes 23 and 43 can form the insertion hole 8 (see...). Figure 3 ).

[0080] When viewed axially, winding 19 is a wire wound into a loop. The winding is also called a coil. The two ends of winding 19 are electrically connected to the external terminals of motor 1. The external terminals of motor 1 are electrically connected to a drive device (e.g., an inverter) that drives motor 1 by power supplied by a power source.

[0081] The winding 19 is arranged axially between a pair of magnetic cores 20 and 40. The winding 19 is wound in such a way that an outer peripheral portion 19a is located radially inward than the outer peripheral surfaces 24b and 44b of the first yoke 24 and 44, and an inner peripheral portion 19b is located radially outward than the inner peripheral surfaces 24a and 44a of the first yoke 24 and 44.

[0082] By contacting at least one of the pair of magnetic cores 20 and 40, the heat dissipation effect of the winding 19 can be improved. For example, the winding 19 can be axially clamped between the first yoke 24 and the first yoke 44 while in axial contact with one or both of the first yoke 24 and the first yoke 44. The winding 19 can also contact one or both of the second yoke 25 and the second yoke 45. The winding 19 can also contact at least one of the pair of magnetic cores 20 and 40 via a bobbin (not shown).

[0083] The winding 19 can be insulated using known methods such as a core mold or a bobbin (winding frame). Insulation methods such as winding insulating tape onto an empty magnetic core coil or molding it are also available. The wire used for the winding 19 can be any type of wire, such as round wire, square wire, or stranded wire, but square wire and aligned wound round wire are preferred.

[0084] like Figure 3 As shown, a pair of magnetic cores 20 and 40 are combined in a manner in which the claw poles 22 of one magnetic core 20 and the claw poles 42 of the other magnetic core 40 are arranged alternately in the circumferential direction. Specifically, the multiple claw poles 22 of one magnetic core 20 are formed to alternate with the claw poles 42 of the other magnetic core 40 in the circumferential direction of the stator core 9 (the circumferential direction of the stator 13). It should be noted that this arrangement is also possible when the number of claw poles 22 of the magnetic core 20 and the number of claw poles 42 of the magnetic core 40 are both one. In this case, the arrangement of one claw pole 22 alternating with one claw pole 42 in the circumferential direction means that one claw pole 42 is located in the circumferential direction on one side of the claw pole 22 and in the circumferential direction on the other side of the claw pole 42.

[0085] After armature current flows into the annular winding 19, the claw pole 22 of one of the pair of magnetic cores 20 and 40 and the claw pole 42 of the other magnetic core 40 are magnetized, each having a different magnetic pole. Accordingly, in the pair of magnetic cores 20 and 40, one claw pole 22 protruding from one magnetic core 20 has a circumferentially adjacent magnetic pole that is different from the other claw pole 42 protruding from the other magnetic core 40. Therefore, by means of the armature current flowing in the winding 19, combinations of N-pole claw pole 22 and S-pole claw pole 42, as well as combinations of N-pole claw pole 42 and S-pole claw pole 22, are alternately generated in the circumference of the stator core 9 (the pair of magnetic cores 20 and 40).

[0086] With the winding 19 sandwiched between a pair of magnetic cores 20 and 40, multiple internal teeth 26 may or may not protrude axially from the magnetic core 40, and multiple internal teeth 46 may or may not protrude axially from the magnetic core 20. The axial length of the stator core 9 can be adjusted by inserting a spacer inside the pair of magnetic cores 20 and 40.

[0087] The yoke of one of the pair of magnetic cores 20 and 40 has at least one yoke surface that is substantially parallel to the axial direction and is in contact with or close to the other magnetic core. In this example, the yoke 21 of the magnetic core 20 has a yoke surface 29 that is in contact with or close to the yoke surface 49 of the yoke 41 of the magnetic core 40 and a yoke surface 30 that is in contact with or close to the yoke surface 50 of the yoke 41 of the magnetic core 40.

[0088] The magnetic yoke surface 29 is a surface provided on each of the plurality of internal teeth 26 (26a, 26b, 26c, 26d) of the second yoke 25, and faces one side in the circumferential direction. Figure 3 , 4 (Clockwise direction). 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 yoke 25, and faces the other side in the circumferential direction. Figure 3 , 4 (The middle direction is counterclockwise). The magnetic yoke surface 50 is a surface provided on each of the plurality of internal teeth 46 (46a, 46b, 46c, 46d) of the second yoke 45, and faces one side in the circumferential direction. Figure 3 , 4 (Clockwise direction). 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 yoke 45, and faces the other side in the circumferential direction. Figure 3 , 4 (The middle direction is counterclockwise).

[0089] Each of the multiple internal teeth 26 contacts or approaches two adjacent internal teeth 46 along the circumferential direction and on both sides of itself. In other words, each of the multiple internal teeth 46 contacts or approaches two adjacent internal teeth 26 along the circumferential direction and on both sides of itself. Specifically, the internal teeth 26a of the yoke 21 contact or approach the yoke surface 49 of the internal tooth 46a adjacent to it on one side of the circumferential direction with the yoke surface 29, and contact or approach the yoke surface 50 of the internal tooth 46d adjacent to it on the other side of the circumferential direction with the yoke surface 30. The other internal teeth are the same. 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.

[0090] Furthermore, in this example, the yoke 21 of the magnetic core 20 has an outer peripheral surface 31 that contacts or approaches the inner peripheral surface 44a of the yoke 41 of the magnetic core 40, and the yoke 41 of the magnetic core 40 has an outer peripheral surface 51 that contacts or approaches the inner peripheral surface 24a of the yoke 21 of the magnetic core 20. The inner peripheral surfaces 24a and 44a and the outer peripheral surfaces 31 and 51 are all yoke surfaces that are approximately parallel to the axial direction.

[0091] 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 yoke 25, and faces 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 yoke 45, and faces radially outward.

[0092] Thus, the electric motor 1 of the first embodiment has a configuration in which the yoke of one of the magnetic cores 20 and 40 has at least one yoke surface that is substantially parallel to the axial direction, and this yoke surface contacts or approaches the other magnetic core. With this configuration, the magnetic cores 20 and 40 can be formed by pressing the powder cores along the axial direction. Even if the dimensional accuracy in the pressing direction is poor, the dimensional accuracy of the yoke surface is unlikely to decrease because it is substantially parallel to the pressing direction. Therefore, the reduction in the axial dimensional accuracy of the stator core 9 can be suppressed.

[0093] In addition, when multiple stator units are stacked along the rotor axis, the magnetic flux linked to the windings of the multiple stator units becomes unbalanced, resulting in a decrease in the motor torque.

[0094] Figure 5 This is a diagram illustrating an example of an unbalanced state in which the magnetic flux linked to the windings of multiple stator units stacked along the rotor axis becomes unbalanced. It shows the waveforms of the voltages induced in the windings of the U, V, and W phase stator units when the rotor is rotated at a certain speed with the rotor shaft as the center. Figure 5 The diagram shows that the induced voltage generated on each winding of the stator unit in phases U and W is less than the induced voltage generated on the winding of the stator unit in phase V. The induced voltage generated on the winding is proportional to the magnetic flux linked to the winding. That is, Figure 5 It is shown that the linkage flux of the windings of phases U and W located on opposite sides of the axial direction is less than that of the winding of phase V located on the inner side of the axial direction. If the linkage flux with the windings of phases U and W is less, the torque generated by the stator units of phases U and W will decrease, resulting in a decrease in the torque generated by the entire motor.

[0095] In this regard, in the first embodiment of this disclosure, as Figure 1 As shown, the rotor 10 has at least one permanent magnet 12 that faces at least a portion of any claw pole of the stator 13 radially at a predetermined rotational position. Since the multiple claw poles are arranged circumferentially, the claw pole facing a permanent magnet 12 radially varies with the rotational position of the rotor 10. At least one of the axial magnet ends of the permanent magnet 12 (one or both axial magnet ends of the permanent magnet 12) is as follows: Figure 1 The magnet end protrudes axially beyond all the claw poles of the stator 13. By protruding axially beyond all the claw poles of the stator 13, the magnetic flux linking with the windings 19 of the stator units 14 and 16 of the U and W phases located on both sides of the axial direction increases by an amount equivalent to the protrusion of the magnet end, thereby suppressing the reduction of torque of the motor 1. That is, the torque of the motor 1 can also be increased by the length of the protrusion of the magnet end.

[0096] Next, see Figures 6-12 Several configuration examples of motor 1 (motor 1A to 1G) will be described. Figures 6-12 It is a schematic diagram of a cross section parallel to the axis passing through the axis AX, in which only one radial side of the axis AX is shown. Figures 6-12 The rotor core 11 shown has a generally cylindrical sidewall 11a, an end plate 11b located on one side of the axial direction, and an end plate 11c located on the other side of the axial direction. End plate 11b is an end face connected to one end of the sidewall 11a in the axial direction, and end plate 11c is an end face connected to the other end of the sidewall 11a in the axial direction. It should be noted that one or both of end plates 11b and 11c may not be present.

[0097] The claw poles 22 and 42 of adjacent stator units of different phases are arranged axially. The claw poles 22 and 42 of the U-phase stator unit 14 and the claw poles 22 and 42 of the V-phase stator unit 15 are located adjacent to each other in the axial direction. The claw poles 22 and 42 of the V-phase stator unit 15 and the claw poles 22 and 42 of the W-phase stator unit 16 are located adjacent to each other in the axial direction.

[0098] De represents the length by which the magnet end 12a (or magnet end 12b) on one side of the permanent magnet 12 protrudes axially from all the claw poles 22, 42 of the stator 13. Dr represents the distance from magnet end 12a to end plate 11b (or from magnet end 12b to end plate 11c). Dp is the sum of De and Dr. Di represents the length of the axial spacing between adjacent stator units (or the axial thickness of the non-magnetic layers 17, 18). By adjusting the values ​​of De, Dr, and Di, the magnetic flux generated by magnet ends 12a, 12b and linked to the windings of each phase can be increased or decreased.

[0099] Figure 6 This is a partial cross-sectional view of a first configuration example of the rotary electric motor in the first embodiment. Figure 6 In the illustrated motor 1A, the magnet ends 12a and 12b on both axial sides of the permanent magnet 12 protrude axially beyond all the claw poles 22 and 42 of the stator 13. Because the magnet ends 12a and 12b protrude axially beyond all the claw poles 22 and 42, the magnetic flux linked to the windings 19 of the stator units 14 and 16 located on both axial sides of the U and W phases can be increased by an amount equivalent to the protrusion of the magnet ends 12a and 12b. As a result, a reduction in the torque of the motor 1A can be suppressed.

[0100] In the multiple stator units of phases U, V, and W, stator unit 14 of phase U is an example of an outer stator unit located on the outer side in the axial direction, and stator unit 15 of phase V is an example of an inner stator unit located on the inner side in the axial direction. The magnet end 12a protrudes axially from the claw poles 22 and 42 of stator unit 14 of phase U, so as to reduce the difference between the linkage flux of winding 19 of stator unit 14 of phase U and the linkage flux of winding 19 of stator unit 15 of phase V. Accordingly, since the difference between the torque generated by stator unit 14 of phase U and the torque generated by stator unit 15 of phase V is reduced, the torque imbalance between stator units 14 and 15 can be reduced.

[0101] Similarly, among the multiple stator units of phases U, V, and W, stator unit 16 of phase W is an example of an outer stator unit located on the outer side in the axial direction, and stator unit 15 of phase V is an example of an inner stator unit located on the inner side in the axial direction. The magnet end 12b protrudes axially from the claw poles 22 and 42 of stator unit 16 of phase W, so as to reduce the difference between the linkage flux of winding 19 of stator unit 16 of phase W and the linkage flux of winding 19 of stator unit 15 of phase V. Accordingly, since the difference between the torque generated by stator unit 16 of phase W and the torque generated by stator unit 15 of phase V is reduced, the torque imbalance between stator units 15 and 16 can be reduced.

[0102] To reduce the difference in linkage flux among the windings 19 of the multiple stator units 14, 15, and 16 in the U, V, and W phases, the magnet end 12a can protrude axially further than the claw poles 22 and 42 of the stator unit 14 in the U phase, and the magnet end 12b can protrude axially further than the claw poles 22 and 42 of the stator unit 16 in the W phase. Accordingly, since the difference in torque generated by each of the stator units 14, 15, and 16 in the U, V, and W phases is reduced, the torque imbalance among the stator units 14, 15, and 16 can be decreased.

[0103] Multiple stator units 14, 15, and 16 of phases U, V, and W are arranged with adjacent stator units spaced apart, and a portion of the permanent magnet 12 is radially opposed to this spacing. Accordingly, the magnetic flux linked to each winding 19 of the axially adjacent stator unit can be increased by the amount generated by the radially opposed portion of the permanent magnet 12. As a result, a reduction in the torque of the motor 1A can be suppressed.

[0104] exist Figure 6In the example shown, the multiple permanent magnets 12 each include multiple (three in this example) magnet components 112, 212, and 312 arranged axially. The lower end of magnet component 112 and the upper end of magnet component 212 face the interval between adjacent stator units 14 and 15 radially. Accordingly, the magnetic flux linked with each winding 19 of stator units 14 and 15 can increase the amount generated by the portion of the permanent magnet 12 facing the interval radially, thus suppressing the decrease in torque of motor 1A. Similarly, the lower end of magnet component 212 and the upper end of magnet component 312 face the interval between adjacent stator units 15 and 16 radially. Accordingly, the magnetic flux linked with each winding 19 of stator units 15 and 16 can increase the amount generated by the portion of the permanent magnet 12 facing the interval radially, thus suppressing the decrease in torque of motor 1A.

[0105] The motor 1A has a non-magnetic layer 17 at the interval between adjacent stator units 14 and 15, and a non-magnetic layer 18 at the interval between adjacent stator units 15 and 16. Since the leakage flux between adjacent stator units can be suppressed by the non-magnetic layers 17 and 18, the reduction in torque of the motor 1A can be further suppressed.

[0106] exist Figure 6 In the example shown, the axially adjacent magnet components 112 and 212 (in this example, the contact surface (or a small gap) between the lower end of magnet component 112 and the upper end of magnet component 212) are radially spaced relative to the axially adjacent stator units 14 and 15. Accordingly, the magnetic flux linked to each winding 19 of stator units 14 and 15 can increase the amount generated by the portion of the permanent magnet 12 radially facing this gap, thus suppressing a decrease in the torque of motor 1A. Similarly, the axially adjacent magnet components 212 and 312 (in this example, the contact surface or a small gap between the lower end of magnet component 212 and the upper end of magnet component 312) are radially spaced relative to the axially adjacent stator units 15 and 16. Accordingly, the magnetic flux linked to each winding 19 of stator units 15 and 16 can increase the amount generated by the portion of the permanent magnet 12 radially facing this gap, thus suppressing a decrease in the torque of motor 1A.

[0107] Figure 7 This is a partial cross-sectional view of a second configuration example of the rotary electric machine in the first embodiment. In the second configuration example, the description of the same configuration as the above configuration example is omitted and simplified by referring to the description of the above configuration example.

[0108] exist Figure 7In the illustrated motor 1B, the axial end 12a of the permanent magnet 12 protrudes axially from all the claw poles 22, 42 of the stator 13. Because the axial end 12a protrudes axially from all the claw poles 22, 42, the magnetic flux linked to the winding 19 of the stator unit 14 located on the axial side of the U phase increases by an amount equivalent to the protrusion of the magnet end 12a. As a result, a decrease in the torque of the motor 1B can be suppressed.

[0109] Figure 8 This is a partial cross-sectional view of a third configuration example of the rotary electric machine in the first embodiment. In this third configuration example, the description of the same configuration as the above configuration example is omitted and simplified by referring to the description of the above configuration example.

[0110] exist Figure 8 In the illustrated electric motor 1C, multiple permanent magnets 12 each include multiple (two in this example) magnet components 112 and 212 arranged axially. The intermediate portion between the upper and lower ends of magnet component 112 is radially spaced relative to adjacent stator units 14 and 15. Accordingly, the magnetic flux linked to each winding 19 of stator units 14 and 15 increases the amount generated by the radially spaced portion of the permanent magnet 12, thus suppressing a decrease in the torque of the electric motor 1C. Similarly, the intermediate portion between the upper and lower ends of magnet component 212 is radially spaced relative to adjacent stator units 15 and 16. Accordingly, the magnetic flux linked to each winding 19 of stator units 15 and 16 increases the amount generated by the radially spaced portion of the permanent magnet 12, thus suppressing a decrease in the torque of the electric motor 1C.

[0111] Figure 9 This is a partial cross-sectional view of the fourth configuration example of the rotary electric machine in the first embodiment. In the fourth configuration example, the description of the same configuration as the above configuration example is omitted and simplified by referring to the description of the above configuration example.

[0112] exist Figure 9 In the illustrated electric motor 1D, multiple permanent magnets 12 are each composed of a magnet component 112. The middle portion between the upper and lower ends of the magnet component 112 faces the intervals of adjacent stator units 14 and 15 and adjacent stator units 15 and 16 radially. Accordingly, the magnetic flux linked with each winding 19 of stator units 14, 15, and 16 can be increased by the amount generated by the portion of the permanent magnet 12 facing the interval radially, thus suppressing the reduction in torque of the electric motor 1D.

[0113] In addition, each permanent magnet 12 is a magnet component 112, thereby improving the assemblability of the permanent magnet 12 to the rotor core 11.

[0114] Figure 10 This is a partial cross-sectional view of the fifth configuration example of the rotary electric machine in the first embodiment. In the fifth configuration example, the description of the same configuration as the above configuration example is omitted and simplified by referring to the description of the above configuration example.

[0115] exist Figure 10 In the electric motor 1E shown, the multiple permanent magnets 12 each include multiple (two in this example) magnet components 112 and 212 arranged axially. A gap 12c is provided between axially adjacent magnet components 112 and 212. By adjusting the axial length of the gap 12c, the length of the magnet ends 12a and 12b protruding axially from the claw poles 22 and 42 can be adjusted, thus enabling fine adjustments to the increase or decrease of the torque of the electric motor 1E.

[0116] Figure 11 This is a partial cross-sectional view of the sixth configuration example of the rotary electric machine in the first embodiment. In the sixth configuration example, the description of the same configuration as the above configuration example is omitted and simplified by referring to the description of the above configuration example.

[0117] exist Figure 11 In the electric motor 1F shown, the multiple permanent magnets 12 each include multiple (six in this example) magnet components 112, 212, 312, 412, 512, and 612 arranged axially. By increasing the number of axially arranged magnet components, the degrees of freedom for adjusting the length of the magnet ends 12a and 12b protruding axially from the claw poles 22 and 42 can be increased, thus enabling easy fine-tuning of the torque of the electric motor 1F.

[0118] Figure 12 This is a partial cross-sectional view of the seventh configuration example of the rotary electric machine in the first embodiment. In the seventh configuration example, the description of the same configuration as the above configuration example is omitted and simplified by referring to the description of the above configuration example.

[0119] In such Figure 12 In the motor 1G shown, there may be no gap between adjacent stator units, and there may be no non-magnetic layers 17 and 18. In this way, the component structure can be simplified, thereby improving the assemblability of the motor 1G.

[0120] Although the embodiments have been described above, various modifications can be made to them as long as they do not depart from the spirit and scope of the patent application. Various variations and improvements can also be made by combining or substituting some or all of the embodiments with other embodiments.

[0121] For example, when the yoke has axially opposing surfaces, it is preferable that the axially opposing surfaces do not contact each other, or that the distance between the axially opposing surfaces is longer than the distance between yoke surfaces that are approximately parallel to the axial direction. Accordingly, even if the axial dimension error increases, the error can be absorbed.

[0122] For example, in the above embodiment, the motor 1 is an external rotor claw pole motor in which the rotor 10 is arranged radially outside the stator 13. However, the rotary motor disclosed herein is also applicable to an internal rotor claw pole motor in which the rotor is arranged radially inside the stator. In the case of an internal rotor type, the rotary motor may have 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.

[0123] This international application claims priority based on Japanese Patent Application No. 2020-089014, filed on May 21, 2020, the contents of which are incorporated herein by reference in their entirety.

[0124] [Explanation of reference numerals in the attached figures]

[0125] 1. 1A to 1G motors

[0126] 8 insertion holes

[0127] 9 stator core

[0128] 10 rotors

[0129] 11 rotor core

[0130] 11a sidewall

[0131] 11b and 11c end plates

[0132] 12 permanent magnets

[0133] The ends of magnets 12a and 12b

[0134] 12c gap

[0135] 13 stators

[0136] 14-16 stator units

[0137] 17 and 18 Non-magnetic layers

[0138] 19 windings

[0139] 19a peripheral part

[0140] 19b Inner Peripheral Section

[0141] 20 and 40 cores

[0142] 21, 41 Magnetic Yoke

[0143] 22, 42 claw magnetic poles

[0144] 23, 43 center holes

[0145] 24, 44 1st yoke part

[0146] 24a, 44a inner circumferential surfaces

[0147] 24b, 44b outer peripheral surfaces

[0148] 25, 45 2nd yoke

[0149] 26a, 26b, 26c, 26d, 46a, 46b, 46c, 46d internal teeth

[0150] 27, 28, 47, 48 Claw Magnetic Pole Sections

[0151] 29, 30, 49, 50 magnetic yoke surfaces

[0152] 31, 51 outer periphery

[0153] 112, 212, 312, 412, 512, 612 magnet components

[0154] AX is the axis of rotation.

Claims

1. A rotary electric motor, comprising: The rotor is generally cylindrical or generally cylindrical in shape and is configured to rotate freely; and The stator is generally annular and arranged radially along the rotor and about the rotor's axis of rotation. in, The stator has multiple stator units stacked along the axial direction of the rotor. The plurality of stator units each have: The winding is wound into a generally loop shape around the axis of rotation; The stator core is arranged to surround the windings; and One or more claw poles protrude radially from two ends of the stator core toward the rotor. The claw poles protruding from one of the two ends are formed to alternate with the claw poles protruding from the other of the two ends in the circumferential direction of the stator. The rotor has a magnet that faces at least a portion of any of the claw poles of the stator along the radial direction at a predetermined rotational position. At least one of the magnet ends along the axial direction of the magnet protrudes from all the claw poles of the stator along the axial direction. The end of the magnet protrudes along the axial direction from the claw pole of the outer stator unit, which is located on the outer side of the plurality of stator units, by such an amount that the protrusion is adjusted such that the difference between the linkage flux of the winding of the outer stator unit and the linkage flux of the winding of the inner stator unit, which is located on the inner side of the plurality of stator units, is reduced.

2. The rotary motor as claimed in claim 1, wherein, The ends of the magnets on both sides of the axial direction protrude along the axial direction from all the claw poles of the stator.

3. The rotary motor as described in claim 1 or 2, wherein, The plurality of stator units are configured such that adjacent stator units are spaced apart. A portion of the magnet faces the interval along the radial direction.

4. The rotary motor as described in claim 3, wherein, A non-magnetic element is provided at the interval.

5. The rotary motor as described in claim 1 or 2, wherein, The magnet is a magnetic component.

6. The rotary electric motor as described in claim 1 or 2, wherein, The magnet includes a plurality of magnet components arranged along the axial direction. The spacing between adjacent magnet components in the plurality of magnet components along the radial direction between adjacent stator units in the plurality of stator units.

Images