Permanent magnet synchronous motor

Abstract

The permanent magnet synchronous motor (50) is provided with a stator (8), a plurality of teeth (2T) arranged on the stator (8) at equal intervals in angle, and coils (1) wound on the plurality of teeth (2T) in a concentrated winding manner. The coils (1) form a three-phase delta connection. In a magnetic closed circuit, a magnetic flux generated from a coil (1) wound around one of two adjacent teeth included in a plurality of teeth (2T) passes through the tip portions of the two teeth, passes through a coil (1) wound around the other of the two teeth, and returns to the coil (1) wound around the one of the two teeth through the core seat portions of the two teeth. The magnetic resistance of the magnetic closed circuit when the coils (1) wound around the two teeth are in the same phase is smaller than the magnetic resistance of the magnetic closed circuit when the coils (1) wound around the two teeth are out of phase.

Description

Technical Field

[0001] The invention relates to a permanent magnet synchronous motor with delta connection. Background Art

[0002] In recent years, electric motors with small torque pulsation are required in various applications. For example, electric motors with small torque pulsation are required in industrial servomotors, hoists for elevators, electric power steering for vehicles, etc. Generally speaking, in the connection of an electric motor driven by a three-phase power supply, either a star connection or a delta connection is selected, but in order to reduce the terminal voltage, a delta connection is advantageous. Patent document 1 discloses a technology related to a permanent magnet motor with a delta connection.

[0003] A permanent magnet motor with a delta connection has the following problem: circulating current is generated in the loop constituting the delta connection. The circulating current causes torque pulsation, so the circulating current should be reduced as much as possible. Patent document 2 discloses the following technology, that is, in order to reduce the circulating current generated in the delta connection, a unit is provided in the rotor to reduce the spatial harmonic component of the magnetic flux density generated by the permanent magnet.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2005-348522

[0005] Patent Document 2: Japanese Patent Application Publication No. 2008-301652 Summary of the invention

[0006] However, when a unit for reducing spatial harmonic components is provided in the rotor, there will be limitations in the manufacture of the rotor. In addition, when a unit for reducing spatial harmonic components such as skew is provided in the rotor, not only the harmonics but also the fundamental waves will be reduced, so there is a problem of reducing the average torque of the motor.

[0007] The present invention is proposed in view of the above situation, and its purpose is to obtain a permanent magnet synchronous motor that can reduce the circulating current generated in the delta connection without reducing the average torque as much as possible, and reduce the torque pulsation caused by the circulating current.

[0008] In order to solve the above problems and achieve the purpose, the permanent magnet synchronous motor involved in the present invention has: a stator; a plurality of teeth, which are arranged on the stator at equal intervals in angle; and a coil, which is wound around each of the plurality of teeth in a concentrated winding manner, and each coil forms a three-phase delta connection. In a magnetic closed loop in which the magnetic flux generated by the coil wound around one of two adjacent teeth included in the plurality of teeth passes through the front end of the two teeth and passes through the coil wound around the other tooth of the two teeth, and returns to the coil wound around one tooth through the core seat of the two teeth, the magnetic resistance of the magnetic closed loop when the coils wound around the two teeth are in the same phase is smaller than the magnetic resistance of the magnetic closed loop when the coils wound around the two teeth are out of phase.

[0009] Effects of the Invention

[0010] The permanent magnet synchronous motor according to the present invention has the effect of reducing the circulating current generated in the delta connection without reducing the average torque as much as possible, thereby reducing the torque ripple caused by the circulating current. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram showing the structure of the permanent magnet synchronous motor according to the first embodiment.

[0012] Figure 2 It is a cross-sectional view of the permanent magnet synchronous motor according to the first embodiment.

[0013] Figure 3 This is a first diagram showing the connection of coils included in the permanent magnet synchronous motor according to the first embodiment.

[0014] Figure 4 The second diagram shows the connection of the coils included in the permanent magnet synchronous motor according to the first embodiment.

[0015] Figure 5 This is a schematic diagram showing teeth of a stator of the permanent magnet synchronous motor according to the first embodiment.

[0016] Figure 6 This is a cross-sectional view showing a main part of teeth of a stator in an example of the permanent magnet synchronous motor according to the first embodiment.

[0017] Figure 7 This is a cross-sectional view showing a main part of teeth of a stator in another example of the permanent magnet synchronous motor according to the first embodiment.

[0018] Figure 8 This is a cross-sectional view showing a main part of a stator tooth in still another example of the permanent magnet synchronous motor according to the first embodiment.

[0019] Fig. 9 It is a cross-sectional view showing a main part of teeth of a stator of a permanent magnet synchronous motor according to the second embodiment.

[0020] Fig.10 It is a cross-sectional view showing a main part of teeth of a stator of a permanent magnet synchronous motor according to a third embodiment.

[0021] Fig.11 It is a cross-sectional view showing a main part of teeth of a stator of a permanent magnet synchronous motor according to a fourth embodiment.

[0022] Fig.12 This is a cross-sectional view showing a main part of teeth of a stator in an example of a permanent magnet synchronous motor according to the fifth embodiment.

[0023] Fig.13 This is a cross-sectional view showing a main part of teeth of a stator in another example of the permanent magnet synchronous motor according to the fifth embodiment.

[0024] Fig.14 This is a cross-sectional view showing a main part of teeth of a stator in another example of the permanent magnet synchronous motor according to the fifth embodiment.

[0025] Fig.15 It is a cross-sectional view showing a main part of teeth of a stator of a permanent magnet synchronous motor according to a sixth embodiment.

[0026] Fig.16 It is a cross-sectional view showing a main part of teeth of a stator of a permanent magnet synchronous motor according to a seventh embodiment.

[0027] Fig.17 It is a perspective view showing a main part of teeth of a stator of a permanent magnet synchronous motor according to the eighth embodiment.

[0028] Fig.18 This is a cross-sectional view showing a main part of a stator tooth applied to a permanent magnet synchronous motor having a tapered tooth structure. DETAILED DESCRIPTION

[0029] Hereinafter, a permanent magnet synchronous motor according to an embodiment will be described in detail with reference to the drawings.

[0030] Implementation method 1.

[0031] Figure 1: This is a schematic diagram showing the structure of the permanent magnet synchronous motor 50 involved in Embodiment 1. The permanent magnet synchronous motor 50 has a stator 8 and a rotor 9. The stator 8 has a stator core 2 and a coil 1 wound around the stator core 2 in a concentrated manner, and is fixed to the frame 6 by methods such as shrink fitting or press fitting. A part of the stator core 2 is a tooth. The permanent magnet synchronous motor 50 has a plurality of teeth arranged at equal angles on the stator 8. The coil 1 is wound around each of the plurality of teeth in a concentrated winding manner. The permanent magnet synchronous motor 50 is a permanent magnet synchronous motor in which each coil 1 forms a three-phase delta connection. The rotor 9 has a rotor core 3 and a permanent magnet 4, and is fixed to the shaft 7. A rotation sensor 5 for detecting a rotation angle is provided on the shaft 7. The rotation sensor 5 can be, for example, a resolver, or a structural element composed of a magnet and a Hall element.

[0032] Figure 2 It is a cross-sectional view of the permanent magnet synchronous motor 50 according to the first embodiment. Figure 2 Schematically shows the Figure 1 The permanent magnet synchronous motor 50 according to the first embodiment is cut off by the II-II line. Figure 1 The same number as Figure 1 . As described above, the coil 1 is concentratedly wound around the teeth 2T of the stator core 2. The method of winding the coil 1 around the teeth 2T is the so-called "concentrated winding" method. There are 12 teeth 2T, which are arranged at equal intervals of the mechanical angle. The 12 teeth 2T are an example of a plurality of teeth. The permanent magnet synchronous motor 50 is a 10-pole 12-slot motor in which a total of 10 permanent magnets 4 are arranged around the rotor core 3 and 12 coils 1 are arranged in the circumferential direction of the stator 8. The 10 permanent magnets 4 are magnetized in the radial direction of the rotor 9. The magnetization direction of a permanent magnet 4 is opposite to the magnetization direction of the permanent magnet 4 adjacent to the permanent magnet 4.

[0033] The permanent magnet synchronous motor 50 has three-phase coils 1. Each of the three phases is any one of a U phase, a V phase, and a W phase.

[0034] The reference numerals U1+, U1-, U2+, U2-, V1+, V1-, V2+, V2-, W1+, W1-, W2+, and W2- without lead wires each represent a coil 1. In order to distinguish between coils that have different directions of magnetomotive force generated when current flows, + or - is added. For example, U1+ and U1- are adjacent coils 1 in the same phase, but the winding directions of the two coils 1 of U1+ and U1- are opposite, or the connection of the jumper wire is improved to make the directions of the current flowing in the two coils 1 opposite, so that the direction of the magnetomotive force of U1+ becomes opposite to the direction of the magnetomotive force of U1-. In the first embodiment, the coils 1 are arranged in the order of U1+, U1-, W1-, W1+, V1+, V1-, U2-, U2+, W2+, W2-, V2-, and V2+. These coils 1 are connected to form a three-phase permanent magnet synchronous motor 50 .

[0035] Figure 3 1 is a first diagram showing the connection of the coil 1 included in the permanent magnet synchronous motor 50 according to the first embodiment. Figure 3 In FIG. 1 , U1+, U1−, U2+, and U2− of the coil 1 of the U phase are connected in series, and the coils 1 of the other two phases are connected in the same manner. Figure 3 The so-called delta connection is shown in which the coils 1 of each phase are connected in a loop. In the delta connection, unlike the star connection, a circulating current is generated. The circulating current is as follows. Figure 3 As shown by the black curved arrow in the center of the , the current flows in the 3-phase coil 1 in a circulating manner. If the U-phase current 10 of the circulating current is set to Iu, the V-phase current 11 is set to Iv, and the W-phase current 12 is set to Iw, then Iu=Iv=Iw. As other connection methods, there are Figure 4 The method shown. Figure 4 The second diagram shows the connection of the coil 1 of the permanent magnet synchronous motor 50 according to the first embodiment. U1+ and U1- are connected in series, and U2+ and U2- are connected in series, but "U1+ and U1-" and "U2+ and U2-" are connected in parallel. In this case, Figure 3 Similarly, as in Figure 4 As shown by the black curved arrow in the center, a circulating current is generated.

[0036] Next, the mechanism of generating circulating current is described in detail. If the current flowing in each phase of the delta connection is i u 、i v 、i w , then i u It can be expressed by the following formula (1): vIt can be expressed by the following formula (2): w It can be expressed by the following formula (3).

[0037] [Formula 1]

[0038] i u =i u1 +i cyc …(1)

[0039] [Formula 2]

[0040] i v =i v1 +i cyc …(2)

[0041] [Formula 3]

[0042] i w =i w1 +i cyc …(3)

[0043] i u1 、i v1 、i w1 It is the fundamental wave component of the current of each phase, and is given in a manner that has a phase difference of every 120 degrees in electrical angle. cyc It is a circulating current, and generally has a harmonic of an order 3n times the fundamental wave, and has an equal value in three phases including the phase. n is an integer greater than or equal to 1. The voltage equation in each phase is the following equation (4).

[0044] [Formula 4]

[0045]

[0046] V u 、V v 、V w is the terminal voltage of each phase, E u 、E v 、E w is the no-load induced voltage of each phase, R is the resistance of each phase, L u , L v , L w is the self-inductance of each phase, M uv 、M vw 、M wu is the mutual inductance between u and v, between v and w, and between w and u. p is the operator for time differentiation.

[0047] The terminal voltage, current and no-load induced voltage each contain fundamental and harmonic components, and the fundamental and harmonic components can be separated. If only the harmonic components are separated from the voltage equation of equation (4), the following equation (5) is obtained.

[0048] [Formula 5]

[0049]

[0050] V uh 、V vh 、V wh is the harmonic component of the voltage between the terminals of each phase, E uh 、E vh 、E wh It is the harmonic component of the no-load induced voltage of each phase.

[0051] In a delta connection, three terminals are connected in a ring shape, so the delta connection has a characteristic that the sum of the voltages between the terminals is always 0. That is, the following equation (6) holds.

[0052] [Formula 6]

[0053] V u +V v +V w =0 …(6)

[0054] The relationship of equation (6) holds true for both fundamental waves and harmonics, and the following equation (7) holds true.

[0055] [Formula 7]

[0056] V uh +V vh +V wh =0 …(7)

[0057] Based on equation (5), if the sum of the terminal voltages of each phase is calculated, the following equation (8) is obtained.

[0058] [Formula 8]

[0059] 0=3Ri cyc +3pl a i cyc +(E uh +E vh +E wh ) …(8)

[0060] l a To obtain equation (8), the following equation (9) is used.

[0061] [Formula 9]

[0062]

[0063] E uh 、E vh 、E whSince each has a phase difference of 120 degrees, their sum has a value whose order is not 0 only when it is a multiple of 3. That is, the following equation (10) is obtained.

[0064] [Formula 10]

[0065]

[0066] n is an integer greater than or equal to 1, E 3n is the amplitude of the 3nth harmonic component of the no-load inductive voltage, α 3n is the phase of the 3nth harmonic component of the no-load induced voltage, and ω is the angular velocity of the electrical angle. The above equation (8) can be rearranged as the following equation (11).

[0067] [Formula 11]

[0068]

[0069] By solving the differential equation of formula (11), the magnitude of the circulating current is calculated according to the following formula (12).

[0070] [Formula 12]

[0071]

[0072] Generally speaking, when the motor speed is relatively high, ω la becomes larger, so the size of the circulating current can be approximated according to the following formula (13).

[0073] [Formula 13]

[0074]

[0075] As mentioned above, it can be seen that in order to reduce the circulating current, the 3nth harmonic of the induced voltage, i.e., E 3n , or increase the leakage inductance, i.e. l a That's it.

[0076] The simplest way to increase the leakage inductance is to increase the number of turns of the coil. However, if the number of turns is increased by r times, the leakage inductance becomes r. 2 times, but at the same time the no-load induced voltage also increases r times. As a result, the circulating current is reduced to 1 / r times, but since the magnitude of the torque ripple is determined by the product of the induced voltage and the circulating current, the magnitude of the torque ripple remains unchanged.

[0077] The purpose of the present invention is to increase the leakage inductance without changing the magnitude of the induced voltage. The following describes the structure of the magnetic circuit in the stator that enables the leakage inductance to be increased. The leakage inductance refers to the inductance generated by the magnetic flux generated by the coil of any phase of the U-phase, V-phase and W-phase, which does not interlink with the coil of a different phase from the phase of the coil generating the magnetic flux, and returns to the original coil. Therefore, in order to increase the leakage inductance, it is preferred to reduce the magnetic flux generated by the coil of any phase of the U-phase, V-phase and W-phase, which interlinks with the coil of a different phase, and increase the magnetic flux that does not interlink with the coil of a different phase and returns to the original coil.

[0078] use Figure 5 The following describes reducing the magnetic flux generated by any of the U-phase, V-phase, and W-phase coils that interlinks with the coils of different phases and increasing the magnetic flux that returns to the original coils without interlinking with the coils of different phases. Figure 5 It is a schematic diagram showing teeth of the stator 8 of the permanent magnet synchronous motor 50 according to the first embodiment. Figure 5 For ease of understanding, the 12 teeth are shown unfolded and arranged in a straight line. Coils are wound around each tooth, and the phases of the coils are U+, U-, W-, W+, V+, V-, U-, U+, W+, W-, V-, V+ from the left. If we focus on the second tooth 21 from the left, the magnetic flux generated by the coil wound around the tooth 21, in addition to the component that crosses the gap and interacts with the rotor, there is also a component that travels from the front end of the tooth 21 to the front end of the adjacent tooth, interlinks with the coil wound around the adjacent tooth, passes through the core seat, and returns to the original tooth 21.

[0079] Regarding the tooth 21, there is a magnetic flux passing through the magnetic closed loop 13 passing through the adjacent tooth 22 of the same phase, and a magnetic flux passing through the magnetic closed loop 14 passing through the adjacent tooth 23 of different phases, but the magnetic closed loop 14 contributes to the self-inductance L of the U phase. u Mutual inductance M between phase U and phase W uw In contrast, the magnetic closed loop 13 only contributes to the self-inductance L of the U phase. u Therefore, by increasing the magnetic flux passing through the magnetic closed loop 13 and reducing the magnetic flux passing through the magnetic closed loop 14 , the leakage inductance can be increased.

[0080] That is, in a magnetic closed circuit in which the magnetic flux generated by the coil wound around one tooth of two adjacent teeth included in a plurality of teeth passes through the front end portions of the two teeth, passes through the coil wound around the other tooth of the two teeth, and returns to the coil wound around one tooth, i.e., the original tooth, via the core seat portions of the two teeth, the magnetic resistance of the magnetic closed circuit when the coils wound around the two adjacent teeth are in phase is smaller than the magnetic resistance of the magnetic closed circuit when the coils wound around the two adjacent teeth are out of phase, thereby increasing the magnitude of the leakage inductance, and as a result, reducing the magnitude of the circulating current and the magnitude of the torque pulsation generated by the circulating current. In the following, the magnetic resistance of the magnetic circuit when the coils wound around the two adjacent teeth are in phase is recorded as "magnetic resistance between the same phases", and the magnetic resistance of the magnetic circuit when the coils wound around the two adjacent teeth are out of phase is recorded as "magnetic resistance between the out of phases".

[0081] Next, a specific structure of the permanent magnet synchronous motor 50 in which the magnetic resistance between the same phases is made smaller than the magnetic resistance between the different phases will be described.

[0082] Figure 6 This is a cross-sectional view showing a main part of teeth of a stator in an example of the permanent magnet synchronous motor 50 according to the first embodiment. Figure 6 In order to simplify the description, only the teeth are drawn in a straight line. Figure 6 In FIG. 1 , only three consecutive teeth 22, 21, 23 are depicted. Figure 6 The middle coil is omitted, but a U-phase coil is wound around the center tooth 21, a U-phase coil is wound around one tooth 22 adjacent to the tooth 21, and a W-phase coil is wound around another tooth 23 adjacent to the tooth 21. The combination of phases in the three teeth 21, 22, and 23 is set to a combination of U and W as an example, and there is no problem even if the combination is replaced with a combination of U and V or a combination of V and W. What is important is that the adjacent teeth 21 and 22 are in phase, and the teeth 21 and 23 are out of phase.

[0083] It is conceivable that the tooth 21 is separated into a core portion 211 connected to the adjacent teeth 22 and 23 on the side away from the rotor, a straight portion 212 extending from the core portion 211 in the radial direction toward the rotor, a flange portion 213a extending in the circumferential direction toward the same phase side at the front end on the rotor side of the straight portion 212, and a flange portion 213b extending in the circumferential direction toward the different phase side at the front end on the rotor side of the straight portion 212. However, the core portion 211, the straight portion 212, the flange portion 213a, and the flange portion 213b are merely names used to express the shape characteristics of the tooth 21, and in actual state, the core portion 211, the straight portion 212, and the flange portions 213a and 213b in the tooth 21 do not need to be separate components. The tooth 21 may be formed as an integral component in which the core seat portion 211 , the straight portion 212 and the flange portions 213 a , 213 b are connected as one, or may have a structure in which the core seat portion 211 , the straight portion 212 and the flange portions 213 a , 213 b are actually divided.

[0084] The circumferential length 31a of the flange portion on the same phase side is longer than the circumferential length 31b of the flange portion on the different phase side. That is, the circumferential length of the flange portion extending in the circumferential direction from the front end portion on the rotor side of a certain tooth among the multiple teeth toward the tooth of the same phase adjacent to the certain tooth can be longer than the circumferential length of the flange portion extending in the circumferential direction from the front end portion toward the tooth of the different phase adjacent to the certain tooth. The certain tooth is any tooth among the multiple teeth. As described above, the magnetic resistance between the same phases can be made smaller than the magnetic resistance between the different phases.

[0085] Figure 7 FIG. 2 is a cross-sectional view showing a main part of the teeth of the stator in another example of the permanent magnet synchronous motor 50 according to the first embodiment. Figure 7 In the embodiment, at the front end of the straight portion 212 of the tooth 21, a flange portion 213a protruding in the circumferential direction is provided on the side opposite to the adjacent tooth 22 of the same phase, but a cutout portion 31c is formed on the side opposite to the adjacent tooth 23 of different phase. As described above, the magnetic resistance between the same phases can also be made smaller than the magnetic resistance between the different phases. The cutout portion 31c can also be interpreted as Figure 6 There is a case where the circumferential length 31b of the flange portion on the out-of-phase side has a negative value.

[0086] Figure 8 1 is a cross-sectional view showing a main part of a stator tooth in another example of the permanent magnet synchronous motor 50 according to the first embodiment. Regarding the tooth 21, on the same phase side, the flange portion 31d is connected to the flange portion 32e of the adjacent tooth 22, that is, a closed slot is formed, while on the opposite phase side, there is a gap between the flange portion 31e and the flange portion 33d of the adjacent tooth 23, that is, an open slot is formed. As described above, the magnetic resistance between the same phases can also be made smaller than the magnetic resistance between the different phases.

[0087] As described above, in the first embodiment, in the magnetic closed loop in which the magnetic flux generated by the coil wound around one tooth of two adjacent teeth included in the plurality of teeth passes through the front end portions of the two teeth, passes through the coil wound around the other tooth of the two teeth, and returns to the coil wound around one tooth, i.e., the original tooth, through the core portions of the two teeth, the magnetic resistance of the magnetic closed loop when the coils wound around the two adjacent teeth are in phase is smaller than the magnetic resistance of the magnetic closed loop when the coils wound around the two adjacent teeth are out of phase. Therefore, the permanent magnet synchronous motor 50 according to the first embodiment can reduce the circulating current generated in the delta connection without reducing the average torque as much as possible, and reduce the torque pulsation caused by the circulating current.

[0088] In the example shown in Embodiment 1, there is another common feature regarding the volume of the teeth. Figure 6 As shown, a line dividing the circumferential width of the straight portion of the teeth 21, 22, and 23 into two equal parts is defined as a tooth center line 40, and a line dividing the tooth center lines 40 of two adjacent teeth into two equal parts at a circumferential angle is defined as a tooth boundary line 45. The total volume of the core seat portion, the straight portion, and the flange portion in the range sandwiched by the two adjacent tooth boundary lines 45 can be interpreted as the volume of one tooth. In the examples of the first embodiment, there is a feature that, when one of the two teeth adjacent to a certain tooth is in phase and the other is out of phase, when considering the volume of the one tooth being divided by the tooth center line 40, the volume of the one tooth included on the side closer to the adjacent tooth of the same phase than the tooth center line 40 is greater than the volume included on the side closer to the adjacent tooth of the out of phase than the tooth center line 40.

[0089] That is, when one of two teeth adjacent to a certain tooth among a plurality of teeth is in phase with the certain tooth, and the other of the two teeth adjacent to the certain tooth is out of phase with the certain tooth, the volume of the certain tooth that is closer to the adjacent tooth with the same phase than the tooth center line 40 is greater than the volume that is closer to the adjacent tooth with the out of phase than the tooth center line 40. Specifically, Figure 6 In the example, the volume of the tooth 21 that is closer to the adjacent tooth 22 of the same phase than the tooth center line 40 is greater than the volume of the tooth 21 that is closer to the adjacent tooth 23 of the different phase than the tooth center line 40.

[0090] Implementation method 2.

[0091] In the example shown in the first embodiment, the distance between the flanges of adjacent teeth, i.e., the slot opening width, is different between the in-phase side and the out-of-phase side. The main purpose of the present invention is to reduce the circulating current and reduce the torque pulsation caused by the circulating current, but if the size of the slot opening width varies depending on the location, the rotational symmetry of the magnetic structure will be destroyed, thereby, for example, the cogging torque under no load or the electromagnetic excitation force under load may increase.

[0092] In the second embodiment, the slot opening widths between all adjacent teeth among the plurality of teeth are equal. In the second embodiment, a method is described in which the same effect as that described in the first embodiment is obtained even if the slot opening widths are equal on the same phase side and the different phase side. In other words, a method is described in which the slot opening widths are equal between any two adjacent teeth among all teeth, and the magnetic resistance between the same phase is smaller than the magnetic resistance between the different phases, thereby reducing the circulating current and reducing the torque ripple caused by the circulating current.

[0093] Fig. 9 2 is a cross-sectional view showing the main part of the teeth of the stator of the permanent magnet synchronous motor involved in the second embodiment. Regarding the tooth 21, the radial height 31f of the same phase side at the front end portion farthest from the straight portion among the circumferentially protruding flange portions is higher than the radial height 31g of the different phase side at the front end portion, and the radial height 31h of the same phase side at the root portion is higher than the radial height 31j of the different phase side at the root portion. In other words, the radial height 31f of the same phase side at the front end portion is higher than the radial height 31j of the different phase side at the root portion. That is, in the second embodiment, the radial height of the flange portion extending in the circumferential direction from the front end portion of the rotor side of a certain tooth among the plurality of teeth toward the same phase tooth adjacent to the certain tooth is higher than the radial height of the flange portion extending in the circumferential direction from the front end portion toward the different phase tooth adjacent to the certain tooth. The certain tooth is any tooth among the plurality of teeth. The root portion is the boundary between the straight portion and the flange portion. As described above, the magnetic resistance between the same phases can also be made smaller than the magnetic resistance between the different phases.

[0094] exist Fig. 9 , an example is shown in which the in-phase side is higher than the out-of-phase side in both the height at the tip end of the flange and the height at the root, but as a similar embodiment, even if the height at the tip end of the flange is set to be higher than the out-of-phase side, and the height at the root of the flange is equal on the in-phase side and the out-of-phase side, the magnetic resistance between the in-phase can be made smaller than the magnetic resistance between the out-of-phase. Even if the height at the root of the flange is set to be higher than the out-of-phase side, and the height at the tip end of the flange is equal on the in-phase side and the out-of-phase side, the magnetic resistance between the in-phase can be made smaller than the magnetic resistance between the out-of-phase.

[0095] Implementation method 3.

[0096] Fig.10 1 is a cross-sectional view showing the main part of the teeth of the stator of the permanent magnet synchronous motor involved in the third embodiment. In the core seat portion 211 of the tooth 21, the radial thickness 34a of the side adjacent to the tooth 22 of the same phase is thicker than the radial thickness 34b of the side adjacent to the tooth 23 of different phase. That is, in the third embodiment, the radial thickness of the core seat portion between a certain tooth among the multiple teeth and the tooth of the same phase adjacent to the certain tooth is thicker than the radial thickness of the core seat portion between the certain tooth and the tooth of different phase adjacent to the certain tooth. The certain tooth is any tooth among the multiple teeth. As described above, the magnetic resistance between the same phases can also be made smaller than the magnetic resistance between the different phases.

[0097] Implementation method 4.

[0098] Even if a magnetic resistance increasing unit is provided in part of the magnetic closed loop on the different phase side, the magnetic resistance between the same phase can be made smaller than that between the different phases. In Embodiments 4 to 6, examples of making the magnetic resistance between the same phase smaller than that between the different phases by providing a magnetic resistance increasing unit are described in sequence.

[0099] Fig.11 : This is a cross-sectional view showing the main part of the teeth of the stator of the permanent magnet synchronous motor involved in the fourth embodiment. A spacer 41 as a magnetic resistance increasing part is sandwiched between the core seat portion 211 of the tooth 21 and the core seat portion 231 of the tooth 23 of the phase difference adjacent to the tooth 21. There is no spacer between the core seat portion 211 and the core seat portion 221 of the tooth 22 of the same phase adjacent to the tooth 21, and the core seat portion 211 and the core seat portion 221 are in direct contact. The circumferential length of the core seat portion 211 is reduced by the circumferential length of the spacer 41. The spacer 41 is composed of a non-magnetic material or a member having a higher magnetic resistance than the stator core. The spacer 41 is composed of, for example, plastic, resin, or magnetic slurry. That is, the permanent magnet synchronous motor involved in the fourth embodiment has a spacer, which is inserted between the core seat portion of a certain tooth among a plurality of teeth and the core seat portion of a tooth of the phase difference adjacent to the certain tooth, and has a magnetic permeability lower than that of the material of each of the plurality of teeth. As described above, the magnetic resistance between the same phases can also be made smaller than the magnetic resistance between the different phases.

[0100] As a similar example of embodiment 4, the following structure may be adopted, i.e., a spacer is sandwiched not only between the core seat portion of a certain tooth and the core seat portion of a tooth adjacent to the certain tooth and in a different phase, but also between the core seat portion of the certain tooth and the core seat portion of a tooth adjacent to the certain tooth and in a same phase, and the circumferential length of the spacer on the same phase side is smaller than the circumferential length of the spacer on the different phase side.

[0101] Implementation method 5.

[0102] Fig.12: is a cross-sectional view showing the main part of the teeth of the stator in an example of the permanent magnet synchronous motor involved in the fifth embodiment. A groove portion 42 is formed at the front end portion on the rotor side of the teeth 21, 22, and 23. The center of gravity of the groove portion 42 of the tooth 21 is arranged on the side closer to the tooth 23 of different phase adjacent to the tooth 21 than the tooth center line 40 located at the center of the circumferential direction of the straight portion 212 of the tooth 21. The center of gravity of the groove portion 42 of the teeth 22 and 23 is also arranged on the side closer to the adjacent tooth of different phase than the tooth center line 40 located at the center of the circumferential direction of the straight portion 222 and 232. That is, in the fifth embodiment, the groove portion 42 is formed in each of the plurality of teeth, and the center of gravity of the groove portion 42 is located on the side closer to the tooth of different phase adjacent to the certain tooth than the tooth center line 40 located at the center of the circumferential width of the straight portion of the certain tooth formed with the groove portion 42. The certain tooth is any tooth among the plurality of teeth. As described above, the magnetic resistance between the same phases can also be made smaller than the magnetic resistance between the different phases.

[0103] exist Fig.12 , an example is shown in which the groove 42 is located at a position overlapping the boundary between the straight section and the flange section, but if the center of gravity of the groove 42 is located closer to the adjacent out-of-phase tooth than the tooth center line 40, the groove 42 may be located in the straight section or in the flange section. Fig.12 3 shows an example in which the groove portion 42 has an opening on the rotor side at the tip of the teeth 21 , 22 , 23 , but the opening of the groove portion 42 may be directed toward the coil slot side, and the groove portion 42 may be replaced by a hole portion having no opening.

[0104] Fig.13 1 is a cross-sectional view showing a main part of a tooth of a stator in another example of a permanent magnet synchronous motor according to Embodiment 5. The groove portion 42 is formed on the side of the core seat portion 211, 221, 231 of the teeth 21, 22, 23 opposite to the coil slot. The center of gravity of the groove portion 42 is located closer to the adjacent tooth of different phases than the tooth center line 40 located at the center of the circumference of the straight portion. Specifically, the center of gravity of the groove portion 42 formed in the tooth 21 is located closer to the tooth 23 of different phases adjacent to the tooth 21 than the tooth center line 40 located at the center of the circumference of the straight portion 212. As described above, the magnetic resistance between the same phases can also be made smaller than the magnetic resistance between the different phases. As a secondary effect of the groove portion 42 being formed on the side of the core seat portion 211, 221, 231 opposite to the coil slot, there is an effect that the groove portion 42 can be effectively used as a winding area.

[0105] Fig.141 is a cross-sectional view showing a main part of the teeth of the stator in another example of the permanent magnet synchronous motor according to the fifth embodiment. The groove portion 42 is formed on the outer peripheral side of the core seat portion 211, 221, 231 of the teeth 21, 22, 23. The center of gravity of the groove portion 42 is located closer to the adjacent tooth of different phases than the tooth center line 40 located at the center of the circumference of the straight portion. Specifically, the center of gravity of the groove portion 42 formed in the tooth 21 is arranged closer to the tooth 23 of different phases adjacent to the tooth 21 than the tooth center line 40 located at the center of the circumference of the straight portion 212. As described above, the magnetic resistance between the same phases can also be made smaller than the magnetic resistance between the different phases. As a secondary effect of the groove 42 being formed on the outer peripheral side of the core seat portions 211, 221, 231, there is the following effect, namely, the groove 42 can be used as a positioning or fixing groove during the assembly process such as when stacking the components of the teeth 21, 22, 23, namely the electromagnetic steel plates, or when inserting the teeth 21, 22, 23 into the frame.

[0106] exist Fig.13 and Fig.14 In the example, even if a hole portion without an opening is formed in the core seat portions 211, 221, 231 instead of the groove portion 42, the magnetic resistance between the same phases can be made smaller than the magnetic resistance between the different phases.

[0107] Implementation method 6.

[0108] Fig.15 1 is a cross-sectional view showing a main part of a tooth of a stator of a permanent magnet synchronous motor according to Embodiment 6. The tooth 21 is riveted. The riveted portion 44 is sometimes located on the side close to the tooth 22 of the same phase adjacent to the tooth 21 from the tooth center line 40, sometimes located on the side close to the tooth 23 of the opposite phase adjacent to the tooth 21, and sometimes located above the tooth center line 40. In the entire tooth 21, among the total area of ​​all the riveted portions 44, the area of ​​the portion located on the side close to the tooth 23 of the opposite phase adjacent to the tooth 21 is larger than the area of ​​the portion located on the side close to the tooth 22 of the same phase adjacent to the tooth 21 from the tooth center line 40. That is, in Embodiment 6, a certain tooth among the plurality of teeth has one rivet portion 44 or more, and the total area of ​​the rivet portion 44 included on the side of the tooth of different phases adjacent to the certain tooth closer to the tooth center line 40 located at the center of the circumferential width of the straight portion of the certain tooth is greater than the total area of ​​the rivet portion 44 included on the side of the tooth of the same phase adjacent to the certain tooth closer to the tooth center line 40. The certain tooth is any tooth among the plurality of teeth. As described above, the magnetic resistance between the same phases can also be made smaller than the magnetic resistance between the different phases.

[0109] Implementation method 7.

[0110] Fig.16: is a cross-sectional view showing the main part of the teeth of the stator of the permanent magnet synchronous motor involved in the seventh embodiment. In the seventh embodiment, the additional magnetic component 43 is arranged between the flange parts between the adjacent teeth 21 and 22 of the same phase. The shape of the additional magnetic component 43 is a shape elongated in the direction of the rotation axis of the motor, such as a cylindrical or prism shape. The additional magnetic component 43 can be a rod-shaped component composed of an integral magnet, or a laminated steel plate laminated in the axial direction. In either case, the permanent magnet synchronous motor involved in the seventh embodiment has an additional magnetic component 43, which is located in the space between the flange part of a certain tooth among the multiple teeth and the flange part of the same-phase tooth adjacent to the certain tooth. The certain tooth is any tooth among the multiple teeth. As described above, a magnetic closed loop is formed to facilitate the passage of magnetic flux from the flange part of the tooth 21 to the flange part of the same-phase tooth 22 adjacent to the tooth 21 via the additional magnetic component 43, which can make the magnetic resistance between the same phases smaller than the magnetic resistance between the different phases. In order to form an effective magnetic closed loop, the position of the center of gravity of the additional magnetic component 43 is preferably between the straight lines 431 and 432 of the adjacent teeth 21 and 22 of the same phase, respectively. The straight line 431 connects the ends 331 on the radial coil side of the root of the flange portion on the opposite side of the adjacent teeth of the same phase, and the straight line 432 connects the ends 332 on the radial rotor side of the root of the flange portion.

[0111] Implementation method 8.

[0112] Fig.17 It is a perspective view showing a main part of teeth of a stator of a permanent magnet synchronous motor according to the eighth embodiment. Fig.17 The schematic diagram shows the stacking of two electromagnetic steel sheets forming one tooth. Fig.17 In the direction of A, the same phase teeth and Fig.17 The teeth are adjacent, Fig.17 In the direction of B, the out-of-phase teeth are Fig.17 The teeth are adjacent. The teeth are divided into two sections, the upper side and the lower side in the direction of the rotation axis, and the shape of the flange portion of the tooth is different in the upper section and the lower section. In the upper section, the circumferential length 311a of the flange portion on the same phase side is longer than the circumferential length 311b of the flange portion on the different phase side. In the lower section, the circumferential length 312a of the flange portion on the same phase side is equal to the circumferential length 312b of the flange portion on the different phase side. As described above, the magnetic resistance between the same phases can also be made smaller than the magnetic resistance between the different phases.

[0113] By providing the deflection amount, it is expected that the cogging torque and the electromagnetic vibrating force can be reduced. Fig.17 , an example is shown in which the circumferential length of the flange portion is different on the same phase side and the different phase side in the upper stage of the two-stage deflection amount, but the teeth have the characteristics described in embodiments 2 to 6, thereby obtaining the same effect as that obtained in embodiments 2 to 6. Fig.17 The skew amount is shown as a tooth with two skew amounts, but the tooth may have a skew amount greater than or equal to three skew amounts, and in one or more than or equal to two of the skew amounts greater than or equal to three skew amounts, the magnetic resistance between the same phase is smaller than the magnetic resistance between the different phases. The skew amount is a continuous skew amount in which the shape of the tooth changes continuously, and the tooth may have a characteristic that the magnetic resistance between the same phase is smaller than the magnetic resistance between the different phases in at least a portion of the interval in the direction of the rotation axis. The above continuous skew amount is an oblique skew amount.

[0114] That is, a certain tooth among the plurality of teeth may have a deflection structure that is continuously or discontinuously different depending on the position in the direction of the rotation axis. The certain tooth is any tooth among the plurality of teeth. In this case, in at least a portion of the range in the direction of the rotation axis, the magnetic resistance of the magnetic closed loop when the coils wound by two adjacent teeth including the certain tooth among the plurality of teeth are in phase may be smaller than the magnetic resistance of the magnetic closed loop when the coils wound by the two teeth are out of phase.

[0115] Each of the examples described in Embodiments 1 to 8 can be implemented by easily combining two or three or more elements.

[0116] In the first embodiment, it is described that when one tooth is divided by the tooth center line 40, there is a common feature that the volume included on the side closer to the adjacent teeth of the same phase than the tooth center line 40 is larger than the volume included on the side closer to the adjacent teeth of different phase than the tooth center line 40. Hereinafter, the case where the volume included on the side closer to the adjacent teeth of the same phase than the tooth center line 40 is larger than the volume included on the side closer to the adjacent teeth of different phase than the tooth center line 40 is described as "the volume on the same phase side is larger than the volume on the different phase side". The above feature is applicable to any of the examples described in the second to fifth and eighth embodiments. In the sixth embodiment, the following feature is also applicable to the rivet portion 44, that is, the rivet portion 44 is considered invalid in the original volume of the tooth by forming a magnetic closed loop and passing the magnetic flux, thereby deteriorating the function as a magnetic conductor originally possessed by the tooth, and if the volume of the portion other than the rivet portion 44 is considered as the effective volume of the tooth, the volume on the same phase side is larger than the volume on the different phase side. In embodiment 7, the additional magnetic component 43 also applies the following characteristics, that is, it forms a magnetic closed loop to allow magnetic flux to pass through, and is a component that has the same function as the magnetic conductor that the tooth originally has. Therefore, if the volume of the additional magnetic component 43 is also regarded as part of the volume of the tooth, the volume of the in-phase side is larger than the volume of the out-of-phase side.

[0117] Embodiment 2 illustrates the effect of making the slot opening width equal on the in-phase side and the out-of-phase side. As in Embodiment 2, in each of Embodiments 3 to 7, regardless of whether two adjacent teeth are in-phase or out-of-phase, the slot opening widths can be easily made equal.

[0118] In the design of electric motors, a tapered tooth structure in which the circumferential width of the straight portion of the tooth varies according to the radial direction is often selected for the purpose of, for example, alleviating magnetic saturation at the tooth portion or increasing the winding duty ratio in the coil slot region. The features of the present invention can be applied to a permanent magnet synchronous motor having a tapered tooth structure. Fig.18 This example is shown in FIG. Fig.18 This is a cross-sectional view showing the main part of the teeth applied to the stator of the permanent magnet synchronous motor with a tapered tooth structure. The teeth 21, 22, and 23 have a tapered shape in which the circumferential width of the straight portion gradually decreases from the outer peripheral side to the inner peripheral side. The circumferential length 31a of the flange portion on the same phase side is longer than the circumferential length 31b of the flange portion on the opposite phase side. As described above, even in a permanent magnet synchronous motor with a tapered tooth structure, the magnetic resistance between the same phases can be made smaller than the magnetic resistance between the opposite phases. The circumferential length of the flange portion is interpreted as, for example, the circumferential interval from the end of the outer peripheral side of the root of the flange portion to the front end of the flange portion. The tooth center line 40 interprets the boundary line of the straight portion relative to the two adjacent coil slots as a line that divides the angle into two.

[0119] according to Fig.18 , shows an example in which the unit in which the circumferential length of the flange portion is different on the same-phase side and the opposite-phase side described in Embodiment 1 is applied to a permanent magnet synchronous motor of a tapered tooth structure. Of course, applying each unit described in Embodiments 2 to 8, or a combination of two or more of the units described in Embodiments 1 to 8 to a tapered tooth structure will also obtain the same effect as that obtained in Embodiment 1. In the tapered tooth structure, the common feature that the volume of the same-phase side is larger than the volume of the opposite-phase side also applies.

[0120] The above embodiments are all described by taking a surface permanent magnet synchronous motor (SPMSM) in which permanent magnets are attached to the outer surface of the rotor as an example. An interior permanent magnet synchronous motor (IPMSM) in which permanent magnets are embedded in the rotor can also achieve the same effects as those achieved in the above embodiments.

[0121] In all the examples of the embodiments described so far, the number of poles of the motor is 10 and the number of slots is 12. We also try to consider combinations of other numbers of poles and other numbers of slots. For example, when the number of poles is 8 and the number of slots is 12, the phase sequence of the coils wound on 12 teeth is U+, W+, V+, U+, W+, V+, U+, W+, V+, U+, W+, V+, and any two adjacent teeth are out of phase, and there are no adjacent teeth with the same phase, so the present invention cannot be applied. On the other hand, for example, when the number of poles is 8 and the number of slots is 9, the phase sequence of the coils wound on 9 teeth is U+, U-, U+, W+, W-, W+, V+, V-, V+, and there are both parts where two adjacent teeth are in phase and parts where they are out of phase, so the present invention can be applied.

[0122] Generally speaking, in a concentrated winding motor, when the ratio of the number of poles to the number of slots is 3m±1:3m, and m is an integer greater than or equal to 2, it is known that there are m consecutive coils of the same phase in the phase arrangement order of the coils in the stator. That is, there are both a portion where two adjacent teeth are in phase and a portion where they are out of phase, so the present invention can be applied to a motor where the ratio of the number of poles to the number of slots is 3m±1:3m, and m is an integer greater than or equal to 2.

[0123] The ratio of the number of poles to the number of slots is not limited to 3m±1:3m. When the number of poles is set to P, the number of slots is set to S, and k is set to an integer greater than or equal to 1, it is generally known that the phase arrangement order of the coils in the stator is reversed when P=S-k and when P=S+k. In the arrangement order, if there are two adjacent teeth that are in phase and out of phase, then when the present invention is applied, from the perspective of the magnetic closed loop on the stator side, it can be said that there is no big difference in the effect of increasing the leakage inductance when P=S-k and when P=S+k. However, as shown in formula (12), the magnitude of the circulating current with an order of 3n is expressed by the ratio of the magnitude of the 3nth harmonic of the induced voltage and the impedance in the delta-connected electrical circuit, that is, the following formula (14).

[0124] [Formula 14]

[0125]

[0126] E 3n It is proportional to the electrical angular velocity ω. Therefore, when the rotation speed is high enough, it is considered that R<<3nωl a , so the size of the circulating current is almost independent of ω, but at a slow rotation speed, the size of R is relative to 3nωl aWhen it cannot be ignored, the magnitude of the circulating current has a positive correlation with ω. If the mechanical rotation speed is the same, the electrical angular velocity ω becomes higher when the number of poles is large. Therefore, if the case of P = S-k is compared with the case of P = S+k, the case of P = S-k with a small number of poles, in other words, the case where the number of poles is less than the number of slots, can further reduce the magnitude of the circulating current, especially when the rotation speed is low, so it can be said to be more suitable.

[0127] The structure shown in the above embodiment is just an example, and it is possible to combine with other well-known technologies, and it is possible to combine the embodiments with each other. It is also possible to omit or change a part of the structure without departing from the scope of the subject matter.

[0128] Description of the label

[0129] 1 coil, 2 stator core, 2T, 21, 22, 23 teeth, 3 rotor core, 4 permanent magnet, 5 rotation sensor, 6 frame, 7 shaft, 8 stator, 9 rotor, 10 U phase current, 11 V phase current, 12 W phase current, 13, 14 magnetic closed circuit, 31f radial height of the same phase side at the front end, 31g radial height of the different phase side at the front end, 31h radial height of the same phase side at the root, 31j radial height of the different phase side at the root, 34a radial thickness of the side adjacent to the same phase tooth, 34b radial thickness of the side adjacent to the different phase tooth, 31a circumferential length of the flange portion on the same phase side, 31b convex portion on the different phase side Circumferential length of the edge portion, 31d, 31e, 32e, 33d, 213a, 213b flange portion, 31c cutout portion, 40 tooth center line, 41 spacer, 42 groove portion, 43 additional magnetic component, 44 rivet portion, 45 tooth boundary line, 50 permanent magnet synchronous motor, 211, 221, 231 core seat portion, 212, 222, 232 straight portion, 311a, 312a the circumferential length of the flange portion on the in-phase side, 311b, 312b the circumferential length of the flange portion on the out-of-phase side, 331 the end portion of the radial coil side of the root of the flange portion, 332 the end portion of the radial rotor side of the root of the flange portion, 431, 432 straight lines.

Claims

1. A permanent magnet synchronous motor, comprising: stator; a plurality of teeth arranged on the stator at angularly equal intervals; and a coil wound around each of the plurality of teeth in a concentrated winding manner, Each of the coils forms a three-phase delta connection. The permanent magnet synchronous motor is characterized in that In a magnetic closed loop, a magnetic flux generated by a coil wound around one of two adjacent teeth included in the plurality of teeth passes through the front end portions of the two teeth through the coil wound around the other of the two teeth, and returns to the coil wound around the one tooth through the core portions of the two teeth. The magnetic resistance of the magnetic closed circuit when the coils wound around the two teeth are in phase is smaller than the magnetic resistance of the magnetic closed circuit when the coils wound around the two teeth are in phase.

2. The permanent magnet synchronous motor according to claim 1, characterized in that: The ratio of the number of poles to the number of slots is 3m±1:3m, where m is an integer greater than or equal to 2.

3. The permanent magnet synchronous motor according to claim 1, characterized in that: The number of poles is less than the number of slots.

4. The permanent magnet synchronous motor according to claim 1, characterized in that: The slot opening widths between all adjacent teeth in the plurality of teeth are equal.

5. The permanent magnet synchronous motor according to any one of claims 1 to 4, characterized in that: One of two teeth adjacent to a certain tooth among the plurality of teeth is in phase with the certain tooth, and the other of the two teeth adjacent to the certain tooth is out of phase with the certain tooth, The volume of the tooth that is closer to an adjacent tooth of the same phase than the tooth center line is larger than the volume of the tooth that is closer to an adjacent tooth of different phase than the tooth center line.

6. The permanent magnet synchronous motor according to any one of claims 1 to 3, characterized in that: The circumferential length of a flange portion extending in the circumferential direction from a front end portion on the rotor side of a tooth among the plurality of teeth toward a tooth of the same phase adjacent to the tooth is longer than the circumferential length of a flange portion extending in the circumferential direction from the front end portion toward a tooth of a different phase adjacent to the tooth. The certain tooth is any tooth among the plurality of teeth.

7. The permanent magnet synchronous motor according to any one of claims 1 to 4, characterized in that: A radial height of a flange portion extending in the circumferential direction from a front end portion on the rotor side of a tooth among the plurality of teeth toward a tooth of the same phase adjacent to the tooth is higher than a radial height of a flange portion extending in the circumferential direction from the front end portion toward a tooth of a different phase adjacent to the tooth. The certain tooth is any tooth among the plurality of teeth.

8. The permanent magnet synchronous motor according to any one of claims 1 to 4, characterized in that: The radial thickness of the core seat portion between a certain tooth among the plurality of teeth and a tooth adjacent to the certain tooth and in the same phase is thicker than the radial thickness of the core seat portion between the certain tooth and a tooth adjacent to the certain tooth and in a different phase. The certain tooth is any tooth among the plurality of teeth.

9. The permanent magnet synchronous motor according to any one of claims 1 to 4, characterized in that: A spacer is also provided, which is inserted between the core seat portion of a certain tooth among the plurality of teeth and the core seat portion of a tooth adjacent to the certain tooth and in a different phase, and has a magnetic permeability lower than that of the material of each of the plurality of teeth.

10. The permanent magnet synchronous motor according to any one of claims 1 to 4, characterized in that: A groove portion or a hole portion is formed in each of the plurality of teeth, and the center of gravity of the groove portion or the hole portion is located closer to a tooth of different phase adjacent to the tooth than a tooth center line located at the center of the circumferential width of a straight portion of the tooth in which the groove portion or the hole portion is formed, The certain tooth is any tooth among the plurality of teeth.

11. The permanent magnet synchronous motor according to any one of claims 1 to 4, characterized in that: There is also an additional magnetic component located in a space between a flange portion of a certain tooth among the plurality of teeth and a flange portion of a tooth adjacent to the certain tooth and in the same phase, The certain tooth is any tooth among the plurality of teeth.

12. The permanent magnet synchronous motor according to any one of claims 1 to 4, characterized in that: A certain tooth among the plurality of teeth has one or more rivet parts, The total area of ​​the riveted portion included on a side of a tooth of different phase adjacent to the certain tooth that is closer to a tooth center line located at the center of the circumferential width of the straight portion of the certain tooth is greater than the total area of ​​the riveted portion included on a side of a tooth of the same phase adjacent to the certain tooth that is closer to the tooth center line of the certain tooth, The certain tooth is any tooth among the plurality of teeth.

13. The permanent magnet synchronous motor according to any one of claims 1 to 3, characterized in that: One of the plurality of teeth has a structure in which the amount of deflection varies continuously or discontinuously depending on the position in the direction of the rotation axis. The certain tooth is any tooth among the plurality of teeth, In at least a portion of the range in the direction of the rotation axis, the magnetic resistance of the magnetic closed loop when the coils wound around two adjacent teeth including the certain tooth among the multiple teeth are in phase is smaller than the magnetic resistance of the magnetic closed loop when the coils wound around the two teeth are out of phase.

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