Rotating electrical machine

Abstract

A rotary electric motor with reduced eddy current losses generated in the magnet section of the stator is obtained. It has a rotor (2) and a stator (3) arranged radially opposite to the rotor (2). The stator (3) has a stator core (7), stator coils (8), and magnet sections (9). The stator core (7) has a core seat (10) and teeth (11), the teeth (11) protruding from the core seat (10) toward the rotor (2) and arranged circumferentially. Fixed coils (8) are wound around multiple teeth (11) and arranged in slots (12) formed between adjacent circumferentially arranged teeth (11). The magnet sections (9) in each tooth (11) are formed by multiple permanent magnets (91). The multiple permanent magnets (91) have the same magnetic poles in the circumferential direction and are arranged in the protruding direction of the teeth (11).

Description

Technical Field

[0001] This invention relates to a rotary electric motor having a stator equipped with permanent magnets. Background Technology

[0002] In industrial electric motors, vehicle-mounted electric motors, and other rotating electric motors, there is a demand for miniaturization, high output, and high speed. To address these requirements, rotating electric motors have been proposed with rotors consisting of an iron core and coils and permanent magnets on the stator side. For example, Patent Document 1 discloses a rotating electric motor whose primary magnetic pole component has multiple tooth modules, each tooth module having windings and at least one permanent magnet, which is formed by a single or segmented structure.

[0003] If the rotor of a rotary electric machine is rotated, the magnetic flux generated by the current flowing in the coil links with the permanent magnet. Eddy currents flow through the permanent magnet to counteract the fluctuations in the magnetic flux, causing eddy current losses. Especially in rotary electric machines where the permanent magnet is located on the stator side, the permanent magnet is stationary relative to the rotating magnetic field, resulting in very large eddy current losses and reducing the efficiency of the rotary electric machine. To address this problem, for example, in Patent Document 2, a bonded magnet with an insulating resin as one of its main components is used as the magnet for the magnetic field. Bonded magnets have low conductivity, thus reducing the eddy currents generated in them. However, when using bonded magnets with low conductivity, the magnetic force deteriorates compared to sintered magnets, resulting in a decrease in output.

[0004] Furthermore, in rotary motors with permanent magnets on the rotor side, it has been proposed to reduce eddy current losses by dividing the permanent magnets. For example, Patent Document 3 proposes a permanent magnet type rotary motor having a first permanent magnet formed by a first magnet piece divided along the axial direction of the rotor core, and a second permanent magnet formed by a second magnet piece divided along a direction intersecting the axial direction of the rotor core, wherein the first permanent magnet and the second permanent magnet are respectively inserted into magnet holes in the rotor core.

[0005] Patent Document 1: Japanese Patent Publication No. 2009-509490

[0006] Patent Document 2: Japanese Patent Application Publication No. 2016-32385

[0007] Patent Document 3: Japanese Patent Application Publication No. 2013-176259 Summary of the Invention

[0008] However, in rotating motors with permanent magnets on the stator side, there is no research on dividing the permanent magnets to reduce eddy current losses. It is difficult to effectively suppress eddy currents and reduce eddy current losses based on the orientation of the permanent magnets.

[0009] The present invention was proposed to solve the above-mentioned problems, and its purpose is to obtain a rotary motor that reduces the eddy current losses generated by the permanent magnets provided on the stator side of the rotary motor.

[0010] The rotary electric motor of the present invention has a rotor and a stator arranged opposite each other at radial intervals in the rotor. The stator has: a stator core having a cylindrical core seat and a plurality of teeth, each of the plurality of teeth protruding from the core seat toward the rotor and arranged along the circumferential direction of the rotor; stator coils wound around the plurality of teeth and arranged in slots formed between adjacent teeth in the circumferential direction; and a magnet portion having a plurality of permanent magnets in each of the plurality of teeth, each of the plurality of permanent magnets having the same magnetic poles in the circumferential direction and arranged in the protruding direction of the teeth.

[0011] Furthermore, the rotary electric motor according to the present invention has a rotor and a stator arranged opposite each other at radial intervals in the rotor. The stator has: a stator core having a cylindrical core seat and a plurality of teeth, each of the plurality of teeth protruding from the core seat toward the rotor and arranged along the circumference of the rotor; stator coils wound around the plurality of teeth and arranged in slots formed between adjacent teeth in the circumferential direction; and a magnet portion having a plurality of permanent magnets in each of the plurality of teeth, the plurality of permanent magnets being circumferentially magnetized, and having slots extending in the axial direction of the rotor formed on the surfaces of the permanent magnets in both the protruding direction of the teeth and the axial direction of the rotor.

[0012] The effects of the invention

[0013] According to the rotary motor of the present invention, a magnet portion having a plurality of permanent magnets each having the same magnetic poles in the circumferential direction and arranged in the convex direction of the teeth, or a magnet portion having permanent magnets magnetized in the circumferential direction and having slots extending in the axial direction of the rotor formed on the surfaces of the permanent magnets along both the convex direction of the teeth and the axial direction, thereby interrupting the path of eddy currents in the convex direction of the teeth, thus effectively suppressing the magnitude of eddy currents flowing in the permanent magnets and reducing eddy current losses. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view showing the schematic structure of the rotary electric motor according to Embodiment 1 of the present invention.

[0015] Figure 2 This is a cross-sectional view showing the schematic structure of the rotary electric motor according to Embodiment 1 of the present invention.

[0016] Figure 3 This is a cross-sectional view showing the schematic structure of another example of the rotary electric motor according to Embodiment 1 of the present invention.

[0017] Figure 4 This is a schematic structural diagram of an enlarged portion of the rotary electric motor according to Embodiment 1 of the present invention.

[0018] Figure 5 This is a schematic structural diagram of an enlarged portion of the rotary electric motor according to Embodiment 1 of the present invention.

[0019] Figure 6 This is an explanatory diagram illustrating the eddy currents generated by the permanent magnet of the rotating electric machine according to Embodiment 1 of the present invention.

[0020] Figure 7 This is a graph showing the relationship between the magnitude of the eddy current generated by the permanent magnet of the rotary electric machine according to Embodiment 1 of the present invention and the distance between the protrusion direction of the teeth of the permanent magnet.

[0021] Figure 8 This is a graph showing the relationship between the magnitude of the eddy current generated by the permanent magnet of the rotary electric machine according to Embodiment 1 of the present invention and the distance between the protrusion direction of the teeth of the permanent magnet.

[0022] Figure 9 This is a cross-sectional view showing the schematic structure of another example of the rotary electric motor according to Embodiment 1 of the present invention.

[0023] Figure 10 This is a cross-sectional view showing the schematic structure of another example of the rotary electric motor according to Embodiment 1 of the present invention.

[0024] Figure 11 This is a schematic structural diagram of an enlarged portion of the rotary electric motor involved in Embodiment 2 of the present invention.

[0025] Figure 12 This is a schematic structural diagram of an enlarged portion of the rotary electric motor involved in Embodiment 3 of the present invention.

[0026] Figure 13 This is a schematic structural diagram of an enlarged portion of the rotary electric motor involved in Embodiment 4 of the present invention.

[0027] Figure 14 This is an explanatory diagram illustrating the eddy currents generated by the permanent magnet of the rotating electric machine according to Embodiment 4 of the present invention.

[0028] Figure 15 This is a schematic structural diagram of an enlarged portion of the rotary electric motor involved in Embodiment 4 of the present invention.

[0029] Figure 16 This is a schematic structural diagram of an enlarged portion of the rotary electric motor according to Embodiment 5 of the present invention.

[0030] Figure 17 This is a cross-sectional view showing the schematic structure of another example of the rotary electric motor according to Embodiment 5 of the present invention.

[0031] Figure 18 This is a cross-sectional view showing the schematic structure of the rotary electric motor according to Embodiment 6 of the present invention. Detailed Implementation

[0032] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. In the drawings, identical or equivalent parts are labeled with the same reference numerals.

[0033] Implementation method 1.

[0034] Figure 1 , Figure 2 This is a cross-sectional view showing the schematic structure of the rotary electric motor according to Embodiment 1 of the present invention. Figure 1 It is a cross-sectional view orthogonal to the axis of rotation. Figure 2 It is a sectional view along the axis of rotation. Figure 1 A sectional view along lines A1-A2. (See example.) Figure 1 As shown, the rotary electric motor 1 has: a rotor 2; and a stator 3, which is spaced apart radially outside the rotor 2 and is arranged to surround the rotor 2 in the circumferential direction.

[0035] In the following description, the direction of rotation of rotor 2 is defined as circumferential, the direction of rotation axis 4 of rotor 2 is defined as axial, and the direction from the center of rotation of rotor 2 toward the outer periphery is defined as radial. Furthermore, in the following description, orthogonal directions also include approximately orthogonal directions.

[0036] The rotor 2 has a rotating shaft 4 and a rotor core 5 mounted on the rotating shaft 4. The rotor core 5 is fixed to the rotating shaft 4 by heat fitting, pressing, or the like. The rotor core 5 is provided with a plurality of protrusions 6 that protrude radially outward. The protrusions 6 are spaced apart from each other in the circumferential direction of the rotor core 5.

[0037] The stator 3 has a stator core 7, a stator coil 8, and a magnet portion 9. The stator core 7 is, for example, a magnet made of electromagnetic steel plates stacked axially. The stator core 7 has a cylindrical core seat 10 and a plurality of teeth 11 protruding radially inward from the inner circumferential surface of the core seat 10. That is, each tooth 11 protrudes from the core seat 10 toward the rotor 2 and is spaced apart from each other circumferentially. Slots 12 are formed between adjacent circumferential teeth 11, which are axially extending spaces that open toward the rotor 2. The stator coil 8 wound around the tooth 11 is provided in the slot 12. In addition, a magnet portion 9 is provided at the circumferential center of each of the plurality of teeth 11.

[0038] Magnet portions 9 are provided on multiple teeth 11, extending in both the convex direction and axial direction, and are formed by permanent magnets 91 magnetized in the circumferential direction. Permanent magnets 91 of circumferentially adjacent magnet portions 9 are arranged with their identical magnetic poles facing each other, separated by slots 12. That is, the permanent magnets 91 of magnet portions 9, each provided on multiple teeth 11, have their magnetic poles alternately arranged in the circumferential direction. For example, the magnet portions 9 protrude from the teeth 11 on the inner circumferential surface of the stator core 7, and are covered by the core seat 10 on the outer circumferential surface of the stator core 7. N and S in the figure indicate the magnetic poles of the permanent magnets 91 of the magnet portions 9. For example, rare-earth sintered magnets such as neodymium sintered magnets and magnets with non-zero conductivity such as ferrite magnets are used as permanent magnets 91 of the magnet portions 9.

[0039] In each of the plurality of teeth 11, the magnet section 9 has a plurality of permanent magnets 91 arranged in the convex direction of the tooth 11. The magnet section 9 is divided into a plurality of parts along the convex direction of the tooth 11 by mutually opposing surfaces between the permanent magnets 91. The permanent magnets 91 arranged in the convex direction of the tooth 11 have the same magnetic poles in the circumferential direction. Here, having the same magnetic poles in the circumferential direction among the permanent magnets 91 includes not only the case where the plurality of permanent magnets 91 are magnetized in a consistent circumferential direction, but also the case where they are magnetized in the same circumferential direction within a certain range considering fluctuations. Furthermore, the arrangement of the permanent magnets 91 in the convex direction of the tooth 11 includes not only the case where they are arranged in a direction parallel to the convex direction of the tooth 11, but also the case where they are arranged in a substantially parallel direction. Figure 1 In the example shown, the magnet section 9 is divided into 6 parts, with 6 permanent magnets 91 arranged in a row, but it is not limited to this.

[0040] As described above, the magnet portions 9a and 9b are provided to extend in the convex direction of the teeth 11, thereby reducing the possibility of a short circuit occurring because the magnetic flux passes through the core seat 10 or the teeth 11 instead of the rotor 2. In addition, the circumferentially magnetized permanent magnets 91 are arranged in the convex direction of the teeth 11, thereby increasing the circumferential cross-sectional area of ​​the permanent magnets 91 and improving the torque.

[0041] Here, in Figure 1 The illustration shows an example of a magnet portion 9 having a plurality of permanent magnets 91 arranged in the protruding direction of the teeth 11, but the magnet portion 9 may also have at least one single permanent magnet 91 magnetized in the circumferential direction, and at least one axially extending groove 13 is formed on the surface of the permanent magnet 91 along both the protruding direction of the teeth 11 and the axial direction.

[0042] Figure 3 This is a cross-sectional view showing a schematic structure of another example of the rotary electric motor according to Embodiment 1 of the present invention. For example... Figure 3As shown, the magnet section 9, for example, has a single permanent magnet 91 extending in both the protruding direction and axial direction of the tooth 11. On the surface of the permanent magnet 91 along both the protruding direction and axial direction of the tooth 11, a plurality of slots 13 extending axially are spaced apart from each other along the protruding direction of the tooth 11. The magnet section 9 is divided into multiple regions along the protruding direction of the tooth 11 by the slots 13. The region between adjacent slots 13 along the protruding direction of the tooth 11 and the region from the surface of the permanent magnet 91 along both the direction orthogonal to the protruding direction of the tooth 11 and the axial direction to the slot 13 each correspond to... Figure 1 One of the permanent magnets, 91.

[0043] The groove 13 can be provided through the permanent magnet 91 in the axial direction, or it can be provided in a portion of the axial direction. Additionally, in Figure 3 The illustration shows an example in which grooves 13 are provided on two circumferentially opposite surfaces of the permanent magnet 91 along the protruding direction and axial direction of the tooth 11, but it is also possible to provide grooves on only one surface.

[0044] The stator coil 8 is provided, for example, by concentrating windings on multiple teeth 11 and received in slots 12. The windings of the stator coil 8 are wound relative to the teeth 11 sandwiched by a pair of circumferentially adjacent slots 12. In the figure, the windings wound on the teeth 11 are omitted.

[0045] A rotating magnetic field is generated in the stator coil 8 by supplying a three-phase alternating current. Here, each of the three phases is represented by U-phase, V-phase, and W-phase, respectively. The two U-phase coils in each stator coil 8 are designated U1 and U2, the two V-phase coils are designated V1 and V2, and the two W-phase coils are designated W1 and W2. Each stator coil 8 is, for example, as follows: Figure 1 As shown, the stator coils are arranged in a counter-clockwise order: U1, V1, W1, U2, V2, W2. The stator coils 8 are connected at a common neutral point as series circuits: U1 and U2 connected in series, V1 and V2 connected in series, and W1 and W2 connected in series. A rotating magnetic field is generated by currents flowing through each phase with a 120-degree phase shift.

[0046] Figure 4 , Figure 5 This is a schematic structural diagram showing an enlarged portion of the rotary electric motor according to Embodiment 1 of the present invention. Here, the rotor 2 is configured to rotate counterclockwise. Figure 4 , Figure 5 In the figure, adjacent teeth 11 separated by one slot 12 are designated as teeth 11a and 11b in a counterclockwise order, and magnet portions 9a and 9b are respectively provided on teeth 11a and 11b. Additionally, adjacent protrusions 6 in the rotor 2 are designated as 6a and 6b in a counterclockwise order. In the figure, direction symbol i1 indicates the current flowing in the stator coil 8. (Arrow) This represents the magnetic flux generated by the current flowing in stator coil 8. (Arrow) These are the magnetization directions of magnet sections 9a and 9b, respectively, representing a portion of the magnetic flux generated by the permanent magnets 91 of magnet sections 9a and 9b themselves. Magnet section 9a is assumed to have multiple permanent magnets 91 magnetized as N poles and S poles in a counterclockwise order, and magnet section 9b is assumed to have multiple permanent magnets 91 magnetized as S poles and N poles in a counterclockwise order.

[0047] like Figure 4 As shown, the magnet portions 9a and 9b are positioned in front of the protrusions 6a and 6b of the rotor 2 in the direction of rotation. At this time, the magnetic flux generated by the current flowing from one axial direction to the other (from the near end to the far end of the paper) in the stator coil 8 provided in the slot 12 flows from the tooth 11b along the core seat 10, and after linking with the magnet portion 9a in a direction orthogonal to the protrusion direction of the tooth 11a, it flows from one protrusion 6a of the rotor 2 to the other protrusion 6b and back to the tooth 11b.

[0048] In addition, such as Figure 5 As shown, the magnet portions 9a and 9b are positioned behind the protrusions 6a and 6b of the rotor 2 in the direction of rotation. At this time, the magnetic flux generated by the current flowing from one side of the axial direction to the other (from the far end to the near end of the paper) of the stator coil 8 provided in the slot 12 flows from the tooth 11a along the core seat 10, and after intersecting with the magnet portion 9b in a direction orthogonal to the protrusion direction of the tooth 11b, it flows from one protrusion 6b of the rotor 2 to the other protrusion 6a and back to the tooth 11a.

[0049] As described above, by changing the phase of the current flowing through the stator coil 8, the direction of the magnetic flux through either tooth 11a or tooth 11b is controlled, thereby generating torque. At this time, the positional relationship between the magnet portions 9a and 9b of the stator 3 and the protrusions 6a and 6b of the rotor 2, as well as the change in the phase of the current, cause a change in the magnitude of the magnetic flux linked with the magnet portions 9a and 9b. For example, if the rotor 2 rotates counterclockwise... Figure 4 The state change is Figure 5 In the state of, Figure 4 In the middle, the magnetic flux linked with the magnet part 9a in a direction orthogonal to the convex direction of tooth 11 becomes Figure 5 The positional relationship reduces the eddy current. Therefore, eddy currents flow through the cross-section of the magnet part 9a along both the convex direction and the axial direction of the tooth 11 to cancel out the fluctuation of magnetic flux. In a rotary motor 1 with a permanent magnet 91 provided on the stator 3 side, the magnet part 9 is stationary relative to the rotating magnetic field and extends in the convex direction of the tooth 11. Therefore, when the eddy current flows along the convex direction of the tooth 11, very large eddy current losses occur.

[0050] Figure 6This is an explanatory diagram illustrating the flow of eddy currents generated by the permanent magnet of the rotating electric machine according to Embodiment 1 of the present invention. Figure 5 , Figure 6 In the diagram, the directional symbol and arrow i2 indicate the eddy current generated in the magnet section 9a. (As shown...) Figure 6 As shown, multiple permanent magnets 91 are arranged in the magnet section 9a along the protruding direction of the tooth 11. Therefore, the path of eddy current is interrupted in the protruding direction of the tooth 11 by the contact resistance of the opposing surfaces of the permanent magnets 91. That is, the eddy current flows in a ring shape in each of the multiple permanent magnets 91 forming the magnet section 9a. The interruption of the eddy current path along the protruding direction of the tooth 11 reduces the magnitude of the eddy current and reduces eddy current loss.

[0051] Figure 7 This is a graph showing the relationship between the magnitude of the eddy current in the rotary electric motor according to Embodiment 1 of the present invention and the distance between the protrusion direction of the permanent magnet teeth. The vertical axis Y is the magnitude of the eddy current flowing axially along the cross-section of the permanent magnet 91, and the horizontal axis X is the distance from the surface close to the rotor 2 to its opposite surface among the surfaces of the permanent magnet 91 in the direction orthogonal to the protrusion direction of the teeth 11 and the axial direction. In the figure, the two dashed lines Q1 and Q2 are the magnitudes of the eddy current flowing from one direction of the axial direction of the permanent magnet 91 to the other (from the near end to the far end of the paper), and the magnitudes of the eddy current flowing from the other direction of the axial direction (from the far end to the near end of the paper), respectively. Figure 7 In the figure, the magnitude of the eddy current inside the permanent magnet 91 is represented by the ratio when the magnitude of the eddy current on the surface of the permanent magnet 91 is set to 1.

[0052] When the rotating motor 1 rotates at high speed, the eddy current density concentrates at the surface of the permanent magnet 91 due to the skin effect. Therefore, as Figure 7 As shown, the current flowing axially in the permanent magnet 91 decreases from the surface towards the interior, decreasing to 1 / e of the current flowing on the surface of the permanent magnet 91 at the skin depth d. Here, e denotes the common logarithm. Eddy currents, if the ring diameter decreases, interfere with each other and cancel each other out. For example, in... Figure 7 In the region shown between P1 and P2, the current flowing from one side of the permanent magnet 91 to the other, and the current flowing from the other side to one side, both become greater than or equal to 1 / e of the current flowing on the surface, but cancel each other out. In the figure, the eddy current can be reduced to the size indicated by the solid line Q3.

[0053] Next, the relationship between the length of the protruding tooth 11 of the permanent magnet 91 and the skin depth of the eddy current will be explained. Figure 5 , Figure 6 In the middle, the arrow w m1The length of the protruding direction of the tooth 11 of the permanent magnet 91 is shown. As described above, if the magnetic flux generated by the current flowing in the stator coil 8 links with the permanent magnet 91, eddy currents flow. In this case, the skin depth d of the eddy current flowing in the permanent magnet 91 is expressed as follows, with the carrier angular frequency of the inverter driving the rotating electric machine, i.e., the angular frequency of the current flowing in the stator coil 8, set as ω, the conductivity of the permanent magnet 91 set as σ, and the permeability set as μ.

[0054] [Formula 1]

[0055]

[0056] Let w be the length of the protruding tooth 11 of the permanent magnet 91. m1 In order to reduce eddy current losses due to interference between eddy currents, the length w of the protruding direction of the teeth 11 of the permanent magnet 91 is preferably [value missing]. m1 The skin depth d satisfies the following relationship.

[0057] [Equation 2]

[0058] w m1 ≤2d

[0059] ···(2)

[0060] Figure 8 This is a graph showing the relationship between the magnitude of the eddy current in the rotating electric motor according to Embodiment 1 of the present invention and the radial distance of the permanent magnet. Figure 8 As Figure 7 Another example shows the length w of the protruding direction of the tooth 11 of the permanent magnet 91. m1 The magnitude of the eddy current is determined when the skin depth d satisfies the following formula.

[0061] [Formula 3]

[0062] w m1 =2d

[0063] ···(3)

[0064] like Figure 8 As shown, the length w in the convex direction of the tooth 11 of the permanent magnet 91 m1 When the size is twice the skin depth d, there is no region where the currents flowing in opposite directions along the axial direction of the permanent magnet 91 cancel each other out because they are greater than or equal to 1 / e. As shown in equation (2), the length w of the protruding direction of the tooth 11 of the permanent magnet 91 is... m1If the depth is set to be less than or equal to twice the skin depth d, then in the eddy current flowing in an annular flow, the currents flowing in opposite directions cancel each other out by a region greater than or equal to 1 / e, thus effectively suppressing the eddy current and increasing the eddy current reduction effect.

[0065] Here, the example described is a magnet section 9 in which multiple permanent magnets 91 are arranged in the protruding direction of the teeth 11. However, in the case of a magnet section 9 provided with a single permanent magnet 91 having a groove 13, the length w in the protruding direction of the teeth 11 of the permanent magnet 91 is... m1 This is equivalent to the length between adjacent grooves 13 in the protruding direction of the tooth 11 in the permanent magnet 91 and the length from the surface of the permanent magnet 91 to the groove 13. Similarly, by setting it to be less than or equal to twice the skin depth, the eddy current reduction effect can be increased.

[0066] As described above, in this embodiment, there is a rotor 2 and a stator 3 arranged opposite to each other at radial intervals in the rotor 2. The stator 3 has: a stator core 7 having a cylindrical core seat 10 and a plurality of teeth 11; a stator coil 8 wound around the teeth 11 and arranged in a slot 12; and a magnet portion 9 having a plurality of permanent magnets 91 in each of the plurality of teeth 11.

[0067] The multiple permanent magnets 91 of the magnet section 9 each have the same magnetic poles in the circumferential direction and are arranged along the protruding direction of the teeth 11. Alternatively, the magnet section 9 is formed by a single permanent magnet 91 magnetized in the circumferential direction, and a groove 13 is provided on the surface of the permanent magnet 91 extending axially along both the protruding direction of the teeth 11 and the axial direction. The permanent magnet 91 is magnetized in the circumferential direction, thereby increasing the area of ​​magnetic flux linkage generated by the current flowing in the stator coil 8, and thus increasing the torque.

[0068] The path of the eddy current flowing when the magnetic flux generated by the current flowing in the stator coil 8 links with the magnet section 9 is interrupted by the opposing surfaces between the multiple permanent magnets 91 or by the slots 13 of the permanent magnets 91 along the protruding direction of the teeth 11. This interruption of the eddy current path effectively reduces the magnitude of the eddy current and thus reduces eddy current losses, thereby increasing torque.

[0069] Furthermore, the magnet section 9 can be provided with insulators between the multiple permanent magnets 91 and inside the groove section 13. In addition, the permanent magnets 91 can be individually coated to prevent rust, etc. As a result, eddy currents can be further interrupted, and eddy current losses can be reduced.

[0070] In addition, Figure 1The diagram shows an example where the surface of the magnet portion 9 facing each other in a direction orthogonal to the protrusion direction of the teeth 11, the surface near the rotor 2, protrudes from the teeth 11 on the inner circumferential surface of the stator core 7, and its opposite surface is covered by the core seat 10 on the outer circumferential surface of the stator core 7. However, other arrangements are also possible. Hereinafter, the surface near the rotor 2 among the surfaces facing each other in a direction orthogonal to the protrusion direction of the teeth 11 will be simply referred to as the surface opposite to the rotor 2. Figure 9 , 10 This is a cross-sectional view showing a schematic structure of another example of the rotary electric motor according to Embodiment 1 of the present invention. For example... Figure 9 As shown, the opposite side of the magnet part 9 to the side opposite to the rotor 2 may be exposed on the outer peripheral surface of the stator core 7, while the side opposite to the rotor 2 may be covered by teeth 11 on the inner peripheral surface.

[0071] In addition, such as Figure 10 As shown, the magnet portion 9 is more preferably exposed on both the outer and inner circumferential surfaces of the stator core 7 on the side opposite to the rotor 2 and on its opposite side. If the magnet portion 9 is covered by the core seat 10 or the teeth 11 on the outer or inner circumferential surface of the stator core 7, the magnetic flux will not pass through the rotor 2, but will instead pass through the core seat 10 or the teeth 11, causing a short circuit and reducing the torque of the rotary motor 1. Figure 10 As shown, the magnet portion 9 is exposed on both the outer and inner circumferences of the stator core 7, thereby preventing short circuits in the magnetic flux and suppressing the reduction of torque.

[0072] In addition, Figure 10 In this configuration, the stator core 7 is divided at the central portion of the circumferential direction of the tooth 11, clamping and fixing the magnet portion 9. As described above, the stator core 7 can be a multi-segmented core divided circumferentially.

[0073] Implementation method 2.

[0074] Figure 11 This is an enlarged schematic structural diagram of a portion of the rotary electric motor according to Embodiment 2 of the present invention. Figure 11 In the middle, the positional relationship between the magnet part 9 of the stator 3 and the protrusion 6 of the rotor 2, the phase of the current, and the magnetization direction of each permanent magnet 91 are... Figure 4 Similarities with Embodiment 1. Below, we will omit descriptions of the similarities with Embodiment 1 and focus on the differences.

[0075] like Figure 11 As shown, the magnet section 9 is formed, for example, by a plurality of permanent magnets 91 arranged along the protruding direction of the teeth 11. Furthermore, in this embodiment, the length of the protruding direction of the teeth 11 of the permanent magnets 91 decreases as it approaches the rotor 2 from the outer peripheral side of the stator core 7 to the inner peripheral side.

[0076] like Figure 11As shown, the magnet portions 9a and 9b are positioned in front of the protrusions 6a and 6b of the rotor 2 in the direction of rotation. At this time, if current flows through the stator coil 8 provided in the slot 12 from one direction in the axial direction to the other (from the near end to the far end on the paper), the magnetic flux generated by the current flows from the tooth 11b along the core seat 10, and after intersecting with the magnet portion 9a in a direction orthogonal to the protrusion direction of the tooth 11a, it flows from one protrusion 6a of the rotor 2 towards the other protrusion 6b and back to the tooth 11b.

[0077] When the magnetic flux generated by the current flowing through the stator coil 8 flows toward a protrusion 6a of the rotor 2 via a link with the magnet portion 9a of the tooth 11a, the magnetic flux linking with the magnet portion 9a passes through the dashed line. The magnetic flux passing through the radial outer side of stator core 7, as indicated by the solid line, is compared to the flux passing through the solid line. The magnetic flux passing through the radially inner side is greater. This is because there is a property that the path through the outer periphery of the stator core 7 is longer to reach the rotor 2, and the magnetic flux flows along the shortest path. Therefore, the change in magnetic flux per unit time through the radially outer side of the stator core 7 is also greater than that through the radially outer side, and the eddy current generated in the magnet section 9 is the largest eddy current generated in the permanent magnet 91 closest to the rotor 2. Hereinafter, the permanent magnet 91 closest to the rotor 2 in the magnet section 9 will be specifically referred to as permanent magnet 91p.

[0078] In this embodiment, the length of the tooth 11 of the permanent magnet 91p closest to the rotor 2 on the radial inner side of the stator core 7 among the plurality of permanent magnets 91 arranged along the protruding direction of the tooth 11 is smaller than that of the other permanent magnets 91, thereby making it easier for interference to occur between currents flowing in the opposite direction to the axial direction of the eddy current.

[0079] Here, in Figure 11 In the example described, a magnet section 9 with a plurality of permanent magnets 91 arranged is used. However, in the case where a magnet section 9 with grooves 13 extending in the axial direction are formed on the surfaces of the permanent magnets 91 along both the protruding direction of the teeth 11 and the axial direction, the distance between adjacent grooves 13 of the permanent magnets 91 in the protruding direction of the teeth 11 or the distance from the surface of the permanent magnets 91 to the grooves 13 can be set to decrease as it approaches the rotor 2.

[0080] As described above, a magnet section 9 is formed by a plurality of permanent magnets 91 arranged in the protruding direction of the teeth 11, or a magnet section 9 is formed by a plurality of permanent magnets 91 with a plurality of slots 13 provided along the protruding direction of the teeth 11. This reduces the eddy current flowing in the magnet section 9 and reduces eddy current losses. Furthermore, in this embodiment, when the magnet section 9 is formed by a plurality of permanent magnets 91, the length of the protruding direction of the teeth 11 of the permanent magnets 91 is formed to gradually decrease as it approaches the rotor 2. Additionally, when the magnet section 9 is formed by permanent magnets 91 with slots 13, the length between adjacent slots 13 along the protruding direction of the teeth 11 and the length from the surface of the permanent magnet 91 to the slot 13 are formed to gradually decrease as it approaches the rotor 2. This reduces the annular diameter of the eddy current generated by the permanent magnets 91 that are close to the rotor 2, where eddy currents are easily generated. Since currents flowing in opposite directions easily interfere with each other, eddy currents can be effectively reduced.

[0081] Here, in Figure 11 In the example shown, the length w of the protruding direction of the tooth 11 of the permanent magnet 91 is illustrated. m1 In examples where the size gradually decreases as the magnet approaches the rotor 2, to reduce eddy current losses, the length of the permanent magnet 91p closest to the rotor 2 among the plurality of permanent magnets 91 arranged in the convex direction of the teeth 11 only needs to be smaller than the length of each of the other permanent magnets 91. Similarly, in the case of the magnet portion 9 formed by permanent magnets 91 provided with slot portions 13, the length from the surface of the permanent magnet 91 opposite to the rotor 2 to the slot portion 13 only needs to be smaller than the lengths between the other slot portions 13.

[0082] Implementation method 3.

[0083] Figure 12 This is a simplified structural diagram showing an enlarged portion of the rotary electric motor according to Embodiment 3 of the present invention. Hereinafter, descriptions of the similarities to Embodiment 1 will be omitted, and the description will focus on the differences. Figure 12 In the middle, the phase of the current, the magnetization direction of the permanent magnet 91 and Figure 5 same.

[0084] The magnet section 9 is formed by a plurality of permanent magnets 91 arranged in the protruding direction of the teeth 11. Alternatively, the magnet section 9 is formed by permanent magnets 91 having axially extending grooves 13 provided on both the protruding direction and the axial direction of the teeth 11. Furthermore, in this embodiment, the distance from the radial magnet section 9 to the rotor 2 is greater than the distance from the radial stator core 7 to the rotor 2.

[0085] For example, in the case where a plurality of permanent magnets 91 are arranged in the protruding direction of the tooth 11, the permanent magnet 91p that is closest to the rotor 2 in the protruding direction of the tooth 11 is located radially outward compared to the circumferential surface of the stator core 7 along the rotor 2 side.

[0086] like Figure 12 As shown, magnet 9a is positioned opposite to protrusion 6a of rotor 2, and magnet 9b is positioned behind protrusion 6b of rotor 2 in the direction of rotation. In this case, if current flows through the stator coil 8 provided in slot 12 from one axial direction to the other (from the far end to the near end of the paper), the magnetic flux generated by the current flows from tooth 11a along core 10, links with magnet 9b in a direction orthogonal to the protrusion direction of tooth 11b, and then flows from one protrusion 6b of rotor 2 towards the other protrusion 6a, returning to tooth 11a.

[0087] When the circumferential positions of the surfaces opposite each other along the protruding direction of the convex portion 6a, located on the front side of the rotor 2 in the rotational direction, and the surfaces opposite each other along the protruding direction of the teeth 11a of the magnet portion 9a, located on the front side of the rotational direction, are at the same level, the magnetic flux generated by the current flowing in the stator coil 8 flows from the convex portion 6a at the circumferential position of the magnet portion 9a opposite to the protruding direction of the teeth 11a. At this time, if the magnetic flux links with the magnet portion 9a along the protruding direction of the teeth 11a, eddy currents are generated due to the fluctuation of the magnetic flux. Figure 12 In the example shown, the permanent magnet 91p closest to the rotor 2 is located radially outward compared to the circumferential surface of the stator core 7 along the rotor 2 side, so the magnetic flux does not link with the magnet part 9a but flows in the tooth 11a.

[0088] As described above, a magnet portion 9 having multiple permanent magnets 91 arranged in the protruding direction of the teeth 11, or a magnet portion 9 formed by permanent magnets 91 having axially extending groove portions 13 provided on the surfaces of the permanent magnets 91 along both the protruding direction of the teeth 11 and the axial direction, can reduce the eddy current flowing in the magnet portion 9 and reduce eddy current losses. Furthermore, in this embodiment, the distance from the radial magnet portion 9 to the rotor 2 is greater than the distance from the radial stator core 7 to the rotor 2, thus suppressing the magnetic flux generated by the current flowing in the stator coil 8 from linking with the magnet portion 9 along the protruding direction of the teeth 11, and further reducing eddy current losses.

[0089] Implementation method 4.

[0090] Figure 13 This is a simplified structural diagram showing an enlarged portion of the rotary electric motor according to Embodiment 4 of the present invention. Hereinafter, descriptions of the similarities to Embodiment 1 will be omitted, and the description will focus on the differences. Figure 13 In the middle, the phase of the current, the magnetization direction of the permanent magnet 91 and Figure 5 same.

[0091] The magnet section 9 is formed, for example, by a plurality of permanent magnets 91 arranged in the protruding direction of the tooth 11. In this embodiment, the magnet section 9 has a plurality of permanent magnets 91 arranged in a direction orthogonal to the protruding direction of the tooth 11.

[0092] exist Figure 13 In the example shown, among the multiple permanent magnets 91 arranged in the convex direction of the tooth 11, the permanent magnet 91p that is closest to the rotor 2 in the convex direction of the tooth 11 is divided into two permanent magnets 911p and 912p in a direction orthogonal to the convex direction of the tooth 11.

[0093] like Figure 13 As shown, magnet 9a is positioned opposite to protrusion 6a of rotor 2, and magnet 9b is positioned behind protrusion 6b of rotor 2 in the direction of rotation. In this case, if current flows through stator coil 8 provided in slot 12 from one direction in the axial direction (from the far end to the near end of the paper), the magnetic flux generated by the current flows from tooth 11a along core 10, links with magnet 9b in a direction orthogonal to the protrusion direction of tooth 11b, and then flows from protrusion 6b of rotor 2 towards protrusion 6a, back to tooth 11a.

[0094] When the face of the protrusion 6a facing each other along the protruding direction of the convex portion 6a, located in front of the rotor 2 in the direction of rotation, and the face of the tooth 11a of the magnet portion 9a facing each other along the protruding direction of the convex portion 11a, located in front of the rotor 2 in the direction of rotation, are in the same circumferential position, the magnetic flux generated by the current flowing in the stator coil 8 flows from the convex portion 6a along the protruding direction of the tooth 11a to the circumferential position of the magnet portion 9a opposite to the convex portion 6a. At this time, if the magnetic flux along the protruding direction of the tooth 11a links with the magnet portion 9a, eddy currents are generated to cancel out the fluctuation of the magnetic flux.

[0095] Figure 14 This is an explanatory diagram illustrating the flow of eddy currents generated by the permanent magnet of the rotating electric machine according to Embodiment 4 of the present invention. Figure 14 As shown, when the magnetic flux along the protruding direction of the tooth 11 links with the magnet portion 9a, the eddy current i3 flows in a ring shape in the cross-sections of the permanent magnets 911p and 912p along the direction orthogonal to the protruding direction of the tooth 11 and in the axial direction. That is, current flows in opposite directions in the axial direction on both sides of the permanent magnets 911p and 912p in the circumferential direction.

[0096] As described above, the magnet section 9, which has a plurality of permanent magnets 91 arranged in the protruding direction of the teeth 11, can reduce the eddy current flowing in the magnet section 9 and reduce eddy current losses. Furthermore, in this embodiment, the plurality of permanent magnets 91 arranged in a direction orthogonal to the protruding direction of the teeth 11 breaks the path of the eddy current flowing in the same direction. Therefore, even if the magnetic flux in the protruding direction of the teeth 11 is linked, the currents flowing in opposite directions along the axial direction of the eddy currents cancel each other out, reducing the eddy current and further reducing eddy current losses. In particular, since the magnetic flux along the protruding direction of the teeth 11 easily links, dividing the permanent magnet 91p closest to the rotor 2 in a direction orthogonal to the protruding direction of the teeth 11 further improves the reduction of eddy current losses.

[0097] In addition, Figure 13 , Figure 14 The example shown is that only the permanent magnet 91p closest to the rotor 2 is divided in a direction orthogonal to the convex direction of the tooth 11, but other permanent magnets 91 can also be divided in a direction orthogonal to the convex direction of the tooth 11.

[0098] Alternatively, instead of dividing the magnet portion 9 into multiple parts along a direction orthogonal to the protrusion direction of the tooth 11, a permanent magnet 91 with an axially extending groove portion 14 can be provided on the surface opposite to the rotor 2. Figure 15 This is a cross-sectional view showing a schematic structure of another example of the rotary electric motor according to Embodiment 4 of the present invention. Figure 15 In the example shown, the groove 14 is provided in the axial direction of the surface of the permanent magnet 91p of the rotor 2 that is closest to the protruding direction of the tooth 11 to the side opposite to the rotor 2.

[0099] As described above, when the slot 14 is provided, the path of the eddy current generated by the magnetic flux linkage along the protruding direction of the tooth 11 of the magnet part 9 is also interrupted in a direction orthogonal to the protruding direction of the tooth 11, thereby reducing the magnitude of the eddy current. In addition, compared with the case where multiple permanent magnets 91 are used as the magnet part 9, the arrangement of the tooth 11 becomes easier, and the assemblability of the stator 3 is improved.

[0100] Here, the slot 14 may extend through the magnet portion 9 in the axial direction, or it may not extend through it, but rather it may be provided in part of the axial direction. However, it is preferable that the axial length of the slot 14 is as large as possible relative to the axial length of the magnet portion 9. By increasing the axial length of the slot 14, the reduction effect of eddy current loss caused by eddy current interference can be improved.

[0101] Furthermore, let w be the length of the permanent magnet 91, which is divided in a direction orthogonal to the protrusion direction of the tooth 11. m2 When the skin depth d is preferably satisfied, the following relationship should be met.

[0102] [Formula 4]

[0103] w m2 ≤2d

[0104] ···(4)

[0105] As shown in equation (4), the length w of the permanent magnet 91 in the direction orthogonal to the protruding direction of the tooth 11 is... m2 If the current is set to be less than or equal to twice the skin depth d, a region is generated in which the currents flowing in opposite directions of the eddy currents are greater than or equal to 1 / e and cancel each other out. Therefore, they can effectively cancel each other out and increase the eddy current reduction effect.

[0106] Here, in the case of a magnet portion 9 formed by a permanent magnet 91 with groove 14 provided in a direction orthogonal to the protruding direction of tooth 11, the distance from the surface of permanent magnet 91 to groove 14 or the distance between grooves 14 is set to be less than or equal to twice the skin depth d, thereby similarly increasing the eddy current reduction effect.

[0107] Implementation method 5.

[0108] Figure 16 This is a schematic structural diagram showing an enlarged portion of the rotary electric motor according to Embodiment 5 of the present invention. Hereinafter, descriptions of the similarities to Embodiment 1 will be omitted, and the description will focus on the differences. Figure 16 In the middle, the phase of the current, the magnetization direction of the permanent magnet 91 and Figure 5 same.

[0109] The magnet section 9 is formed, for example, by a plurality of permanent magnets 91 arranged in the protruding direction of the teeth 11. Alternatively, the magnet section 9 is formed by permanent magnets 91 having, for example, grooves 13 extending in the axial direction provided on both the axial and axial surfaces. In this embodiment, the permanent magnets 91 of the magnet section 9 have a chamfered surface 15 formed by removing the corner formed by the intersection of the surfaces in the protruding direction and axial direction of the teeth 11 and the surface opposite to the rotor 2. Hereinafter, the corner formed by the intersection of the surfaces in the protruding direction and axial direction of the permanent magnets 91 and the surface opposite to the rotor 2 will be simply referred to as the corner on the side opposite to the rotor 2.

[0110] exist Figure 16 In the example shown, the permanent magnet 91p closest to the rotor 2 among the permanent magnets 91 arranged in the convex direction of the teeth 11 has its front corner in the direction of rotation opposite to the rotor 2 removed to form a chamfered surface 15. The cross-sectional shape of the permanent magnet 91p orthogonal to the axial direction is a pentagon.

[0111] like Figure 16As shown, magnet 9a is located opposite to the protrusion 6a of rotor 2, and magnet 9b is located behind the protrusion 6b of rotor 2 in the direction of rotation. At this time, if current flows through the stator coil 8 provided in slot 12 from the opposite direction of the axial direction (from the far end to the near end of the paper), the magnetic flux generated by the current flows from tooth 11a along core seat 10, links with magnet 9b in a direction orthogonal to the protrusion direction of tooth 11b, and then flows from the protrusion 6b of rotor 2 toward the protrusion 6a and back to tooth 11a.

[0112] When the circumferential positions of the faces of the rotor 2 opposite each other along the protrusion direction of the protrusion 6a and the faces of the teeth 11a opposite each other along the protrusion direction of the magnet 9a are at the same level, the magnetic flux generated by the current flowing in the stator coil 8 flows from the protrusion 6a along the protrusion direction of the teeth 11a to the circumferential position of the magnet 9a opposite to the protrusion 6a. At this time, if the magnetic flux links with the magnet 9a along the protrusion direction of the teeth 11a, eddy currents flow through it in a way that cancels out the fluctuation of the magnetic flux, resulting in eddy current losses.

[0113] In this embodiment, the permanent magnet 91p closest to the rotor 2 among the permanent magnets 91 arranged in the convex direction of the teeth 11 has a chamfered surface 15 formed by removing the corner in front of the rotation direction opposite to the rotor 2, so that the magnetic flux does not link from the protrusion 6a and the magnet part 9a back to the teeth 11a.

[0114] As described above, a magnet portion 9 is formed by a plurality of permanent magnets 91 arranged in the protruding direction of the tooth 11, or a magnet portion 91 is formed by permanent magnets 91 having grooves 13 extending in the axial direction provided on both the protruding direction and the axial direction of the tooth 11. This reduces the eddy current flowing in the magnet portion 9 and reduces eddy current losses. Furthermore, in this embodiment, the permanent magnet 91p has a chamfered surface 15 formed by removing the corner portion opposite to the rotor 2. As a result, the magnetic flux does not link from the protrusion 6a and the magnet portion 9a back to the tooth 11a, thus suppressing the occurrence of eddy currents and reducing eddy current losses.

[0115] In addition, Figure 16 The design envisions a counter-clockwise rotation, illustrating an example where the corner of the permanent magnet 91 on the counter-clockwise side opposite to the rotor 2 is cut off. However, in the case of clockwise rotation, it is preferable to remove the corner on the clockwise side of the permanent magnet 91 opposite to the rotor 2. Furthermore, when the rotor 2 rotates in both counter-clockwise and clockwise directions, it is preferable to remove both the counter-clockwise and clockwise corners, resulting in two chamfered surfaces 15.

[0116] Figure 17This is a schematic structural diagram illustrating another example of the rotary electric motor according to Embodiment 5 of the present invention. Figure 17 In the example shown, the permanent magnet 91p has two chamfered surfaces 15, with both the front and rear corners of the permanent magnet 91 opposite to the rotor 2 removed in the direction of rotation. That is, the cross-sectional shape of the permanent magnet 91p orthogonal to the axial direction is hexagonal. As described above, by removing the two corners of the permanent magnet 91p opposite to the rotor 2 and having two chamfered surfaces 15, the eddy current loss of the magnet section 9 can be reduced regardless of the rotation direction of the rotor 2.

[0117] In addition, Figure 16 , Figure 17 The image shows an example where the permanent magnet 91p has its corners removed, resulting in a chamfered surface 15. The cross-sectional shape perpendicular to the axial direction is pentagonal or hexagonal. However, as long as it can suppress the eddy current generated by the magnetic flux from the rotor 2 to the tooth 11, it can also be a polygon with more than one pentagon or hexagon, or it can be an arc shape with the corners removed.

[0118] Implementation method 6.

[0119] Figure 18 This is a cross-sectional view showing the schematic structure of the rotary electric motor according to Embodiment 6 of the present invention. Hereinafter, descriptions of the similarities to Embodiment 1 will be omitted, and the descriptions will focus on the differences. In Embodiments 1 to 6, an example of an inner rotor type rotary electric motor 1 with the rotor 2 arranged radially inside the stator 3 is shown. In this embodiment, an example of an outer rotor type rotary electric motor 1 with the rotor 2 arranged radially outside the stator 3 is shown.

[0120] like Figure 18 As shown, the rotary electric motor 1 has a rotor 2 and a cylindrical stator 3 arranged at intervals on the radially inner side of the rotor 2. The rotor 2 has a rotor core 5. The rotor core 5 is provided with a plurality of protrusions 6 protruding radially inward. The protrusions 6 are arranged at intervals from each other in the circumferential direction of the rotor core 5.

[0121] The stator 3 has a stator core 7, a stator coil 8, and a magnet portion 9. The stator core 7 is, for example, a magnet made of electromagnetic steel plates stacked axially. The stator core 7 has a cylindrical core seat 10 and a plurality of teeth 11 protruding radially inward from the inner circumferential surface of the core seat 10. That is, the plurality of teeth 11 protrude toward the rotor 2 and are spaced apart from each other along the circumferential direction of the core seat 10. The circumferentially adjacent teeth 11 open radially outward from each other to form a space extending axially, i.e., a slot 12. The stator coil 8 wound around the teeth 11 is provided in the slot 12. In addition, a magnet portion 9 is provided at the circumferential center of each of the plurality of teeth 11.

[0122] The magnet section 9 is provided, for example, at the center of each of the plurality of teeth 11, extending in the convex direction and axial direction of the teeth 11, and is formed by a permanent magnet 91 magnetized in the circumferential direction. Permanent magnets 91 of circumferentially adjacent magnet sections 9 are arranged with their identical magnetic poles facing each other, separated by slots 12. That is, the permanent magnets 91 of the magnet sections 9 provided in each of the plurality of teeth 11 have their magnetic poles alternately arranged in the circumferential direction. The magnet section 9, for example, protrudes from the teeth 11 on the inner circumferential surface of the stator core 7, and is covered by the core seat 10 on the outer circumferential surface of the stator core 7. N and S in the figure show the magnetic poles of the permanent magnets 91 of the magnet section 9. For example, rare-earth sintered magnets or ferrite magnets are used as the permanent magnets 91 of the magnet section 9.

[0123] The magnet section 9 is formed by a plurality of permanent magnets 91 arranged in the protruding direction of the tooth 11. Alternatively, the magnet section 9 is formed by a single permanent magnet 91, which has a groove 13 extending in the axial direction at intervals along the protruding direction of the tooth 11 on its surface.

[0124] Having the magnet part 9 as described above, the path of the eddy current can be interrupted in a direction orthogonal to the protrusion direction of the tooth 11. The currents flowing in the opposite direction to the axis of the interrupted eddy current cancel each other out, thus effectively reducing eddy current loss.

[0125] Furthermore, in embodiments 1 to 6, examples are shown where the number of protrusions in the rotor 2 is 5, and the number of teeth 11 and magnet portions 9 in the stator 3 are 6 each. However, the number of poles, the number of slots, and the dimensions of other parts are not particularly limited. For example, the number of protrusions in the rotor 2 could be 4, and the number of teeth 11 and magnet portions 9 in the stator 3 could be 6 each, or the number of protrusions 6 in the rotor 2 could be 10, and the number of teeth 11 and magnet portions 9 in the stator 3 could be 12 each.

[0126] Furthermore, in embodiments 1 to 6, a motor with three-phase windings was described as a rotating motor 1, but this is just an example, and it could also be a motor with multi-phase windings other than three-phase windings.

[0127] Furthermore, within the scope of this invention, the various embodiments can be freely combined, or the various embodiments can be appropriately modified or omitted.

[0128] Explanation of the label

[0129] 1 Rotary motor, 2 Rotor, 3 Stator, 4 Rotary shaft, 5 Rotor core, 6, 6a, 6b Protrusions, 7 Stator core, 8 Stator coil, 9, 9a, 9b Magnet parts, 10 Core base, 11, 11a, 11b Teeth, 12 Slot, 13 Slot part, 14 Slot part, 91, 91p Permanent magnet.

Claims

1. A rotary electric motor, characterized in that, It has a rotor with protrusions and a stator arranged radially spaced apart from the rotor. The stator has: The stator core has a cylindrical core seat and a plurality of teeth, each of which protrudes from the core seat toward the rotor and is arranged along the circumference of the rotor; Stator coils, each wound around the plurality of teeth, are arranged in slots formed between adjacent teeth along the circumferential direction; as well as The magnet section has multiple permanent magnets on each of the plurality of teeth, the plurality of permanent magnets being magnetized in the circumferential direction, and grooves extending in the axial direction of the rotor are formed on two surfaces of the permanent magnets that are opposite to the circumferential direction in both the protruding direction of the teeth and the axial direction of the rotor. The distance from the slot provided on one of the two circumferentially opposite faces of the permanent magnet to the rotor is different from the distance from the slot provided on the other of the two circumferentially opposite faces to the rotor.

2. The rotary motor according to claim 1, characterized in that, The groove is formed alternately on two surfaces that are opposite to the circumferential direction along both the protruding direction of the tooth and the axial direction of the rotor, along the protruding direction of the tooth.

Images