Rotating electric machine

Abstract

To provide a rotating electric machine that further reduces a leakage magnetic flux.SOLUTION: A stator 20 of a rotating electric machine has a stator core 22. The stator core 22 has a plurality of teeth parts 26 extending in a diameter direction of a yoke part 24 in a circular shape. A slot 30 is formed between teeth parts 26 adjacent in a circumferential direction. In the slot 30, a dimension in a width direction at a position of an inner peripheral side tip surface 40a of an electromagnetic coil 40 is determined as a first distance D1. In the width direction, a separation interval between inner peripheral side tip surfaces 26a of teeth parts 26 adjacent to each other is determined as a second distance D2. The second distance D2 is 0.5 times or more of the first distance D1.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a rotating electrical machine including a stator and a rotor.

Background Art

[0002] A rotating electrical machine includes a stator and a rotor that rotates relative to the stator. The stator has electromagnetic coils provided in slots of a stator core. On the other hand, the rotor has a plurality of permanent magnets. When the rotating electrical machine is a generator, the rotor is rotated. Along with this, an induced current is generated in the electromagnetic coils.

[0003] As described in Patent Document 1, it is known to arrange a plurality of permanent magnets in the rotor in a Halbach array. In this case, since the magnetic flux density or the amount of magnetic flux by the plurality of permanent magnets increases, it is expected that the efficiency is improved even in a small-sized rotating electrical machine.

[0004] However, when the stator cannot sufficiently receive the amount of magnetic flux, so-called leakage magnetic flux occurs. The leakage magnetic flux is one of the causes of the generation of circulating current in the electromagnetic coils. As a result of the electromagnetic coils generating heat due to the circulating current, losses occur. For the above reasons, when a small-sized rotating electrical machine is used as a generator, it is not easy to increase the power generation amount.

[0005] The applicant of the present application has proposed a configuration in Patent Document 2 in which the amount of magnetic flux from a plurality of permanent magnets arranged in a Halbach array can be sufficiently received by the stator. In this case, leakage magnetic flux can be reduced.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] In a rotating electrical machine, there is a demand for further reducing leakage magnetic flux.

[0008] An object of the present invention is to solve the above-described problems.

Means for Solving the Problems

[0009] An aspect of the present disclosure is a rotating electrical machine including a stator and a rotor disposed inside the stator. The stator has a stator core and an electromagnetic coil. The stator core includes an annular yoke portion and a plurality of teeth portions each including a paddle portion provided at intervals in the circumferential direction of the stator, protruding from the inner circumferential surface of the yoke portion, and extending in the diameter direction of the yoke portion as an extending direction, and a plurality of slots respectively formed between the teeth portions adjacent to each other in the circumferential direction among the plurality of teeth portions. The electromagnetic coil is provided in the slot.

[0010] The rotor has a plurality of permanent magnets facing the plurality of teeth portions inside the stator. The plurality of permanent magnets include a first magnet whose magnetic field direction is along the inner side in the diameter direction of the yoke portion, a second magnet adjacent to the first magnet and having a magnetic field direction in the clockwise direction or the counterclockwise direction, a third magnet adjacent to the first magnet and having a magnetic field direction in the direction opposite to that of the second magnet among the clockwise direction or the counterclockwise direction, and a fourth magnet adjacent to the third magnet and having a magnetic field direction along the outer side in the diameter direction of the yoke portion, and has two or more combinations thereof.

[0011] The position of the inner circumferential side tip surface of the electromagnetic coil is offset from the inner circumferential side tip of the paddle portion toward the yoke portion. Here, the direction orthogonal to the extending direction is defined as the width direction. And in each of the plurality of slots, the dimension of the slot in the width direction at the position of the inner circumferential side tip surface of the electromagnetic coil is defined as a first distance, and the separation distance between the inner circumferential side tip surfaces of the adjacent tooth portions in the width direction is defined as a second distance. In the above configuration, the second distance is 0.5 times or more of the first distance.

Advantages of the Invention

[0012] According to the present invention, a rotating electrical machine with further reduced leakage magnetic flux in the stator can be obtained.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0014] FIG. 1 is a schematic horizontal sectional view of the main part of the rotating electrical machine 10 according to the present embodiment. This rotating electrical machine 10 includes a stator 20 having a substantially annular shape and a rotor 50 disposed inside the stator 20, and constitutes a three-phase rotating electrical machine (generator) of U-phase, V-phase, and W-phase.

[0015] The stator 20 will be described. The stator 20 has a stator core 22 and electromagnetic coils 40. The stator core 22 is formed, for example, by laminating magnetic materials such as electromagnetic steel sheets. The stator core 22 has an annular yoke portion 24 and a plurality of teeth portions 26. When the distance from the center O, which is the rotation center of the rotor 50, to the outer peripheral surface of the yoke portion 24 is X, twice X is the outer diameter of the stator core 22. In a typical example, the outer diameter of the stator core 22 is about 100 mm to 200 mm. This outer diameter is smaller than that of a general rotating electrical machine. That is, the rotating electrical machine 10 according to the present embodiment is small in outer diameter and small-sized. A more preferable outer diameter of the stator core 22 is about 115 mm to 130 mm.

[0016] The plurality of teeth portions 26 are provided at intervals in the circumferential direction of the stator core 22. Each of the plurality of teeth portions 26 includes a blade portion 32 that starts from the inner peripheral surface of the yoke portion 24 and extends along the diameter direction of the yoke portion 24. Most of each of the several teeth portions 26 is the blade portion 32. The extending direction of the blade portion 32 is the diameter direction of the yoke portion 24. Therefore, the plurality of teeth portions 26 extend radially along the diameter direction of the stator core 22. The configuration of each individual tooth portion 26 will be described in detail later.

[0017] Slots 30 are formed between the teeth portions 26 that are adjacent to each other in the circumferential direction among the plurality of teeth portions 26. Since the rotating electrical machine 10 is a three-phase generator, the number of slots 30 is typically set to a multiple of 3. That is, for example, 24, 30, 36, 48, etc. In the illustrated example, the number of teeth portions 26 and slots 30 is 48. Note that the number of poles (described later) is 8 poles. In this case, the configuration of the rotating electrical machine 10 is a so-called 8-pole 48-slot.

[0018] The electromagnetic coil 40 is formed, for example, by winding a wire made of copper around the tooth portion 26. A part of the wire is passed through the slot 30. Thereby, the electromagnetic coil 40 is provided in the slot 30. Distributed winding is suitable for winding the wire around the tooth portion 26 and the slot 30. The winding of the wire around the tooth portion 26 may also be concentrated winding.

[0019] Instead of winding the wire around the tooth portion 26, the electromagnetic coil 40 may be configured by inserting the leg portions of a substantially U-shaped metal conductor as shown in FIG. 1 of Japanese Patent Application Laid-Open No. 2020-39207 into the slot 30.

[0020] The configuration of the tooth portion 26 will be described. As shown in FIG. 2, each of the plurality of tooth portions 26 has a blade portion 32. Here, the direction orthogonal to the diameter direction of the stator core 22 is defined as the width direction. In the aspect shown in FIG. 2, in the blade portion 32, the first width dimension W1 which is the dimension in the width direction is substantially constant. Also, in this aspect, each of the plurality of tooth portions 26 has a flange portion 34 located on the inner peripheral side of the blade portion 32 and an expanding portion 36 interposed between the blade portion 32 and the flange portion 34.

[0021] The expanding portion 36 expands so as to gradually become wider from the blade portion 32 toward the flange portion 34. The expansion starts at the first virtual straight line LN1 and ends at the second virtual straight line LN2. Therefore, the first virtual straight line LN1 is the inner peripheral side tip 32a of the blade portion 32 and the outer peripheral side end of the expanding portion 36. The second virtual straight line LN2 is the inner peripheral side end of the expanding portion 36 and the outer peripheral side end of the flange portion 34. Further, the third virtual straight line LN3 is the inner peripheral side tip surface 34a of the flange portion 34.

[0022] The flange portion 34 has a second width dimension W2 in the width direction. The second width dimension W2 of the flange portion 34 is larger than the first width dimension W1 of the blade portion 32.

[0023] Further, the flange portion 34 has a thickness T1. The thickness T1 of the flange portion 34 is the shortest distance from the inner peripheral side end face 34a of the flange portion 34 to the outer peripheral side end of the flange portion 34. That is, the thickness T1 of the flange portion 34 is the separation distance between the second virtual straight line LN2 and the third virtual straight line LN3. The thickness T1 of the flange portion 34 is preferably 0.2 mm to 2.0 mm. The thickness T1 of the flange portion 34 is more preferably within the range of 0.3 mm to 1.1 mm.

[0024] The total length LO of the teeth portion 26 is defined as the straight-line distance from the inner peripheral surface of the yoke portion 24, which is the starting point of the paddle portion 32, to the inner peripheral side end face 34a of the flange portion 34. When the diameter of the stator core 22 is within the above-described numerical range, the total length LO of the teeth portion 26 is, for example, within the range of 40 mm to 45 mm. Also, when the total length LO of the teeth portion 26 is taken as 100%, the total length of the paddle portion 32 is preferably 96% or more. That is, in this case, the distance from the inner peripheral side end face 34a of the flange portion 34 to the inner peripheral side tip 32a of the paddle portion 32 is preferably 4% or less of the total length LO of the teeth portion 26.

[0025] Within the slot 30, the position of the inner peripheral side end face 40a of the electromagnetic coil 40 is offset toward the yoke portion 24 side. That is, the direction of the offset of the electromagnetic coil 40 is outward in the diameter direction. The straight-line distance from the inner peripheral side end face 34a of the flange portion 34 to the inner peripheral side end face 40a of the electromagnetic coil 40 is defined as the offset amount OF. The offset amount OF is preferably 5% to 11% of the total length LO of the teeth portion 26. For example, when the total length LO of the teeth portion 26 is 40 mm, a suitable offset amount OF is 2 mm to 4.4 mm. The offset amount OF is more preferably 5.6 to 10.3% with respect to the total length LO of the teeth portion 26.

[0026] When the offset amount OF is less than 5% of the total length LO of the tooth portion 26, the winding amount of the electromagnetic coil 40 around the tooth portion 26 and the slot 30 increases. That is, the volume of the electromagnetic coil 40 becomes large. Accordingly, the amount of magnetic flux received by the electromagnetic coil 40 from the plurality of permanent magnets 54 increases. As a result, the heat generation amount of the electromagnetic coil 40 may increase. Also, the copper loss in the electromagnetic coil 40 increases. On the other hand, when the offset amount OF exceeds 11%, although the copper loss in the electromagnetic coil 40 decreases, the exposed area of the paddle portion 32 may increase. In this case, the iron loss and the heat generation amount in the tooth portion 26 may increase. Also, since the winding amount of the electromagnetic coil 40 around the tooth portion 26 and the slot 30 decreases, the output as a generator tends to decrease.

[0027] Incidentally, when the total length LO of the tooth portion 26 is 40 mm to 45 mm, the specific distance from the first virtual straight line LN1, which is the inner peripheral side tip 32a of the paddle portion 32 (the outer peripheral side end portion of the expanded portion 36), to the inner peripheral side end face 40a of the electromagnetic coil 40 is, for example, about 1 to 3 mm.

[0028] In the slot 30, the dimension in the width direction at the position of the inner peripheral side end face 40a of the electromagnetic coil 40 is defined as the first distance D1. The first distance D1 is defined as follows. A virtual circle Q passing through the inner peripheral side end face 40a of the electromagnetic coil 40 is drawn. A point where the virtual circle Q intersects one of the adjacent tooth portions 26 is defined as the first intersection point P1. A point where the virtual circle Q intersects the remaining one of the adjacent tooth portions 26 is defined as the second intersection point P2. The first distance D1 is the length of the straight line connecting the first intersection point P1 and the second intersection point P2.

[0029] In the radial direction, the separation distance between the inner peripheral side end faces 26a of the teeth portions 26 adjacent to each other is defined as the second distance D2. In the rotating electrical machine 10 of the illustrated example, the inner peripheral side tip of the teeth portion 26 is the flange portion 34. In the case of this aspect, the inner peripheral side end face 26a of the teeth portion 26 refers to the inner peripheral side end face 34a of the flange portion 34. As shown in FIG. 3 described later, in an aspect where the teeth portion 26 has only the blade portion 32 and does not have the expanding portion 36 and the flange portion 34, the inner peripheral side end face 32b of the blade portion 32 corresponds to the inner peripheral side end face 26a of the teeth portion 26. Further, as shown in FIG. 4 described later, in an aspect where the teeth portion 26 has the blade portion 32 and the tapered portion 38 provided on the inner peripheral side of the blade portion 32, the inner peripheral side end face 38a of the tapered portion 38 corresponds to the inner peripheral side end face 26a of the teeth portion 26.

[0030] The first distance D1 and the second distance D2 defined as above have the relationship shown in the following formula (A). 0.5×D1≦D2 …(A) That is, the second distance D2 is 0.5 times or more of the first distance D1. By establishing this relationship between the first distance D1 and the second distance D2, the amount of magnetic flux at the tip of the teeth portion 26 (the flange portion 34 in this aspect) can be reduced as compared with the case where the second distance D2 is 0.5 times or less of the first distance D1.

[0031] As shown in FIGS. 1 and 2, when the teeth portion 26 has the flange portion 34, the second distance D2 becomes smaller than the first distance D1. That is, the relationship of the following formula (B) holds. 0.5×D1≦D2<D1 …(B) In this case, the magnetic flux from the plurality of permanent magnets 54 can be sufficiently received by the flange portion 34 while avoiding an excessive increase in the amount of magnetic flux at the flange portion 34.

[0032] As shown in FIG. 3, even in an aspect where the teeth portion 26 has only the blade portion 32, it is possible to establish the above formula (B). In this case, the magnetic flux from the plurality of permanent magnets 54 can be sufficiently received by the inner peripheral side end face 32b of the blade portion 32 while avoiding an excessive increase in the amount of magnetic flux at the inner peripheral side end face 32b of the blade portion 32.

[0033] For the reasons described above, it is preferable that the above formula (B) holds. However, it is not essential for formula (B) to hold. As shown in FIG. 4, in the aspect where the tooth portion 26 has the blade portion 32 and the tapered portion 38, the following formula (C) may hold. 0.5×D1<D1<D2 …(C) In this configuration, the amount of magnetic flux received by the tapered portion 38 is smaller than that of the flange portion 34 (FIGS. 1 and 2). Therefore, it is possible to avoid an excessive increase in the amount of magnetic flux in the tapered portion 38.

[0034] In addition, the second distance D2 is preferably larger than the diameter DM of the wire material constituting the electromagnetic coil 40. In this case, since the saturation magnetic flux at the tip of the tooth portion 26 is reduced, the magnetic flux that the tooth portion 26 can receive increases. Therefore, it is possible to improve the torque of the rotating electrical machine 10. Further, as the material of the stator core 22 (such as an electromagnetic steel sheet), it is possible to select a magnetic material having a small saturation magnetic flux density. For this reason, it is possible to reduce the material cost.

[0035] The rotor 50 will be described. As shown in FIG. 1, the rotor 50 has a rotating shaft 52 and a plurality of permanent magnets 54. The plurality of permanent magnets 54 are held by the rotating shaft 52.

[0036] The plurality of permanent magnets 54 have a combination of a first magnet 56a, a second magnet 56b, a third magnet 56c, and a fourth magnet 56d. In one set of combinations, the number of the first magnet 56a, the second magnet 56b, the third magnet 56c, and the fourth magnet 56d is one each. In FIG. 1, the number of combinations of the first magnet 56a, the second magnet 56b, the third magnet 56c, and the fourth magnet 56d is four. Therefore, the number of the plurality of permanent magnets 54 is 16.

[0037] In FIG. 1, the arrows attached to the first magnet 56a to the fourth magnet 56d respectively indicate the directions of the magnetic fields of the first magnet 56a to the fourth magnet 56d. As can be understood from FIG. 1, the direction of the magnetic field of the first magnet 56a is along the inward direction in the diameter direction of the rotor 50 and the stator core 22. The direction of the magnetic field of the fourth magnet 56d is outward in the diameter direction of the rotor 50 and the stator core 22. That is, the direction of the magnetic field of the first magnet 56a and the direction of the magnetic field of the fourth magnet 56d are opposite to each other.

[0038] Also, in FIG. 1, the direction of the magnetic field of the second magnet 56b is along the clockwise direction in the circumferential direction of the rotor 50 and the stator core 22. The direction of the magnetic field of the third magnet 56c is counterclockwise in the circumferential direction of the rotor 50 and the stator core 22. That is, the direction of the magnetic field of the second magnet 56b and the direction of the magnetic field of the third magnet 56c are opposite to each other.

[0039] In a set of combinations, the first magnet 56a, the second magnet 56b, the fourth magnet 56d, and the third magnet 56c are arranged in this order along the clockwise direction in FIG. 1. That is, in this embodiment, 16 permanent magnets 54 are arranged in a Halbach array. The first magnet 56a to the fourth magnet 56d face the paddle part 32 through the flange part 34 that constitutes the tooth part 26. In this embodiment, twice the number (number of sets) of the combinations of the first magnet 56a to the fourth magnet 56d is defined as the number of poles. Therefore, the number of poles in the rotating electrical machine 10 shown in FIG. 1 is 8 poles. The number of poles may be 10 poles or 12 poles. Thus, typical numbers of poles are even numbers from 8 poles to 12 poles.

[0040] The rotating shaft 52 holding a plurality of permanent magnets 54 is connected to the output shaft of an internal combustion engine such as a gas turbine engine, for example. Therefore, as the internal combustion engine is operated and the output shaft rotates, the rotating shaft 52 rotates following it. Note that the internal combustion engine and the output shaft are not shown.

[0041] However, the rotating electrical machine 10 can be used alone. That is, it is not essential to couple the rotating electrical machine 10 with an internal combustion engine (such as a gas turbine engine).

[0042] Next, the operation of the rotating electrical machine 10 will be described by way of example when the rotating shaft 52 is connected to the output shaft of the gas turbine engine.

[0043] When the rotating electrical machine 10 is used as a generator, the rotating shaft 52 is rotated by a starter (not shown). Accordingly, the output shaft of the gas turbine engine rotates, and fuel and compressed air are supplied into the gas turbine engine. Thereafter, as the output shaft rotates, the rotating shaft 52 rotates following it.

[0044] As the rotating shaft 52 rotates, an alternating magnetic field is formed between the first magnet 56a to the fourth magnet 56d and the electromagnetic coil 40. Further, an induced current flows through the electromagnetic coil 40. This induced current is taken out to the outside of the rotating electrical machine 10 and is used, for example, as electrical energy for driving a predetermined external load (device).

[0045] The rotating electrical machine 10 may also be operated as a motor. In this case, an alternating current is supplied from an external power source to the electromagnetic coil 40.

[0046] This embodiment has the following effects.

[0047] As shown in FIG. 2, in the slot 30, let the dimension in the width direction at the position of the inner peripheral side tip of the electromagnetic coil 40 be the first distance D1. Also, in the width direction, let the separation interval between the inner peripheral side end faces 26a of the adjacent teeth portions 26 be the second distance D2. In the first distance D1 and the second distance D2 thus defined, the following formula (A) holds. 0.5×D1≦D2 …(A) That is, the second distance D2 is 0.5 times or more the first distance D1.

[0048] FIG. 5 is a graph showing the relationship between the distance from the inner peripheral side end face 26a of the tooth portion 26 and the magnetic flux density when the second distance D2 is about 0.8 times the first distance D1. That is, in this rotating electrical machine 10, the following equation (B') holds. 0.5×D1 < D2 (≒0.8×D1) < D1 …(B’)

[0049] Note that as shown in FIGS. 1 and 2, the tooth portion 26 has a paddle portion 32, a widened portion 36, and a flange portion 34. The second distance D2 is the separation interval in the width direction between the inner peripheral side end faces 34a of the adjacent flange portions 34.

[0050] On the other hand, FIG. 6 is a graph showing the relationship between the distance from the inner peripheral side end face 26a of the tooth portion 26 and the magnetic flux density when the second distance D2 is about 0.4 times the first distance D1. That is, in this rotating electrical machine 10, the first distance D1 and the second distance D2 have the following relationship. D2 (≒0.4×D1) < 0.5×D1 In this case, compared with the case of FIG. 5, the second width dimension W2 (see FIG. 2) of the flange portion 34 is larger, and the second distance D2 is about 0.5 times.

[0051] As can be understood by comparing FIGS. 5 and 6, in the rotating electrical machine 10 in which the equation (A) holds, the magnetic flux density at the inner peripheral side tip of the tooth portion 26 is reduced compared to the rotating electrical machine 10 in which the equation (A) does not hold. Thus, when the first distance D1 and the second distance D2 have the relationship shown in the equation (A), the magnetic flux density at the inner peripheral side tip of the tooth portion 26 becomes small. Along with this, the leakage magnetic flux in the stator 20 is reduced, so the circulating current in the electromagnetic coil 40 is reduced. Therefore, the loss caused by the circulating current can be reduced.

[0052] Figs. 5 and 6 show the results when the electromagnetic coil 40 is wound around the tooth portions 26 and the slots 30 in a distributed winding. Fig. 7 shows the results when the electromagnetic coil 40 is wound around the tooth portions 26 and the slots 30 in a concentrated winding. The rotating electrical machine 10 has 8 poles and 24 slots, and the second distance D2 is about 0.6 times the first distance D1. It can be understood from Fig. 7 that even when the electromagnetic coil 40 is wound around the tooth portions 26 and the slots 30 in a concentrated winding, by satisfying the relationship of the above formula (A), the magnetic flux density at the inner peripheral side tip of the tooth portion 26 becomes small.

[0053] As shown in Fig. 1, a plurality of permanent magnets 54 form a Halbach array. Therefore, the magnetic field intensity from the rotor 50 (a plurality of permanent magnets 54) toward the stator 20 is large. In the rotating electrical machine 10 that satisfies the above formula (B), the tooth portion 26 can sufficiently receive the magnetic flux from the plurality of permanent magnets 54. For this reason, the torque of the rotating electrical machine 10 increases.

[0054] As shown in Figs. 1 and 2, the tooth portion 26 has a flange portion 34. Since the flange portion 34 is wider than the blade portion 32, the tooth portion 26 can receive more magnetic flux from the plurality of permanent magnets 54.

[0055] In the aspect where the tooth portion 26 has a flange portion 34, the offset amount OF shown in Fig. 2 is 5% to 11% of the total length LO of the tooth portion 26. When the offset amount OF is defined in this way, the output as a generator can be increased while reducing the leakage magnetic flux. Thereby, it is avoided that the tooth portion 26 or the electromagnetic coil 40 locally causes a temperature rise. Therefore, it is suppressed that the material (electromagnetic steel sheet, etc.) of the stator core 22 or the material (copper, etc.) of the electromagnetic coil 40 deteriorates due to this temperature rise.

[0056] When the total length LO of the tooth portion 26 is taken as 100%, the length of the blade portion 32 is 96% or more.

[0057] In this case, the amount of winding of the electromagnetic coil 40 around the teeth 26 and the slots 30 is appropriate. Therefore, the rotating electric machine 10 can serve as a generator with sufficient output. Furthermore, the rotating electric machine 10 has small iron loss and copper loss.

[0058] The thickness T1 of the flange portion 34 (the distance from the inner peripheral tip surface 34a to the outer peripheral end) is 0.2 mm to 2.0 mm.

[0059] The flange 34 having such a thickness T1 can easily receive magnetic flux from the multiple permanent magnets 54. This further reduces leakage magnetic flux. In addition, the stator 20 having the flange 34 is prevented from increasing iron loss.

[0060] As illustrated in Figure 1, when the number of poles is twice the number of combinations of the first magnets 56a to the fourth magnets 56d, the number of poles is an even number between 8 and 12, and the number of teeth 26 is a multiple of 3 between 24 and 48.

[0061] In this configuration, the rotor 50 can rotate at high speed because there are a large number of poles and teeth 26. Moreover, it is possible to configure a rotating electrical machine 10 that has a large output as a generator.

[0062] The outer diameter of the stator core 22 (twice the value of X in FIG. 1) is 100 mm to 200 mm.

[0063] In this case, the rotating electric machine 10 is relatively small in size. However, even though it is small, the rotating electric machine 10 exhibits a large output.

[0064] When the outer diameter of the stator core 22 is within the above range, the overall length LO of the teeth portion 26 is 40 mm to 45 mm.

[0065] In this case, the amount of winding of the electromagnetic coil 40 around the teeth 26 and the slots 30 is appropriate, which allows sufficient output to be obtained from the rotary electric machine 10. Furthermore, this configuration can suppress iron loss and copper loss.

[0066] As described above, according to this embodiment, torque can be improved while suppressing heat generation of the rotating electrical machine 10. Moreover, when the rotating electrical machine 10 is used as a generator, the power generation amount can be increased.

[0067] Regarding the above embodiment, the following additional remarks are disclosed.

[0068] (Supplementary Note 1) The rotating electrical machine (10) of the present disclosure includes a stator (20) and a rotor (50) disposed inside the stator. The stator has a stator core (22) and an electromagnetic coil (40). The stator core includes an annular yoke portion (24), and a plurality of teeth portions (26) each including a blade portion (32) provided at intervals in the circumferential direction of the stator, protruding from the inner circumferential surface of the yoke portion, and extending in the extending direction along the diameter direction of the yoke portion, and a plurality of slots (30) respectively formed between the teeth portions adjacent to each other in the circumferential direction among the plurality of teeth portions. The electromagnetic coil is provided in the slot.

[0069] The rotor has a plurality of permanent magnets (54) facing the plurality of teeth portions inside the stator. The plurality of permanent magnets include a first magnet (56a) whose magnetic field direction is along the inner side in the diameter direction of the yoke portion, a second magnet (56b) adjacent to the first magnet and having a magnetic field direction in the clockwise direction or the counterclockwise direction, a third magnet (56c) adjacent to the first magnet and having a magnetic field direction opposite to that of the second magnet among the clockwise direction or the counterclockwise direction, and a fourth magnet (56d) adjacent to the third magnet and having a magnetic field direction along the outer side in the diameter direction of the yoke portion. The combination has two or more sets. Further, the position of the inner circumferential side tip surface (40a) of the electromagnetic coil is offset from the inner circumferential side tip (32a) of the blade portion toward the yoke portion.

[0070] The direction orthogonal to the extending direction is defined as the width direction. And in each of the plurality of slots, the dimension of the slot in the width direction at the position of the inner peripheral side end surface of the electromagnetic coil is defined as the first distance (D1), and the separation distance between the inner peripheral side end surfaces (26a) of the tooth portions adjacent to each other in the width direction is defined as the second distance (D2). In the above configuration, the second distance is 0.5 times or more of the first distance.

[0071] The second distance corresponds to the inner peripheral side opening facing the rotor in the slot. That is, in the above configuration, the inner peripheral side opening of the slot is relatively large. In this case, compared with the case where the inner peripheral side opening of the slot is small, the magnetic flux density at the tip of the tooth portion is reduced. Therefore, the leakage magnetic flux in the stator is reduced, so that the circulating current in the electromagnetic coil is reduced. Thereby, the loss caused by the circulating current can be reduced.

[0072] (Appendix 2) In the rotating electrical machine according to Appendix 1, the second distance may be smaller than the first distance.

[0073] In this case, the tooth portion can sufficiently receive the magnetic flux from the plurality of permanent magnets.

[0074] (Appendix 3) In the rotating electrical machine according to Appendix 1 or 2, the tooth portion is located on the inner peripheral side of the stator core rather than the inner peripheral side tip of the paddle portion, and has a flange portion (34) having a dimension (W2) along the width direction larger than that of the paddle portion, and the electromagnetic coil may be offset with the inner peripheral side end surface (34a) of the flange portion as a base point with 5% to 11% of the total length (LO) of the tooth portion as an offset amount (OF).

[0075] Since there is a flange portion wider than the paddle portion, the tooth portion can receive more magnetic flux from the first magnet to the fourth magnet.

[0076] Moreover, when the offset amount is within the above range, it is possible to increase the output as a generator while reducing the leakage magnetic flux. As a result, it is possible to avoid the local temperature rise of the teeth portion or the electromagnetic coil. Therefore, deterioration of the electromagnetic steel sheet which is the material of the stator core, copper which is the material of the electromagnetic coil, etc. due to the temperature rise is suppressed.

[0077] (Appendix 4) In the rotating electrical machine according to Appendix 2 or 3, when the total length of the teeth portion is 100%, the length of the paddle portion may be 96% or more.

[0078] In this case, the winding amounts of the electromagnetic coil to the teeth portion and the slots are appropriate. Therefore, the rotating electrical machine can constitute a generator having a sufficient output. Further, according to this configuration, it is possible to sufficiently suppress the iron loss and the copper loss.

[0079] (Appendix 5) In the rotating electrical machine according to any one of Appendices 2 to 4, the distance (thickness T1) from the inner peripheral side tip surface to the outer peripheral side end of the flange portion may be 0.2 mm to 2.0 mm.

[0080] According to this configuration, the flange portion can easily receive the magnetic flux from the plurality of permanent magnets. Therefore, the leakage magnetic flux is further reduced. Also, in the stator, an increase in the iron loss is suppressed.

[0081] (Appendix 6) In the rotating electrical machine according to any one of Appendices 1 to 5, when the number of poles is twice the number of sets of the combinations of the first magnet to the fourth magnet, the number of poles is an even number of 8 poles or more and 12 poles or less, and the number of teeth portions is a multiple of 3 of 24 or more and 48 or less.

[0082] In this configuration, since the number of poles is large and the number of teeth portions is large, the rotor can rotate at a high speed. Moreover, it is possible to configure a rotating electrical machine having a large output as a generator.

[0083] (Appendix 7) In the rotating electric machine according to any one of Supplementary Notes 1 to 6, the stator core may have an outer diameter of 100 mm to 200 mm.

[0084] A rotating electrical machine having a stator core with an outer diameter within the above range exhibits a large output despite being relatively small in size.

[0085] (Appendix 8) In the rotating electric machine described in Supplementary Note 7, the total length of the teeth may be 40 mm to 45 mm.

[0086] In this case, in a rotating electric machine with a stator core having an outer diameter within the above range, the amount of winding of the electromagnetic coil around the teeth and slots is appropriate, which allows the rotating electric machine to exhibit sufficient output. Furthermore, this configuration can suppress iron loss and copper loss.

[0087] The present invention is not particularly limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0088] 10... Rotating electric machine 20... Stator 22... Stator core 24... Yoke section 26...Teeth part 30...Slot 32…Shobbe 34…Tsubabe 40...Electromagnetic coil 50...Rotor 54... Permanent magnet 56a to 56d... First magnet to fourth magnet

Claims

1. A rotating electrical machine comprising a stator and a rotor disposed inside the stator, The stator includes an annular yoke portion, a plurality of teeth portions provided at intervals in the circumferential direction of the stator, each including a paddle portion protruding from the inner circumferential surface of the yoke portion and extending in the radial direction of the yoke portion as an extending direction, and a plurality of teeth portions formed between the teeth portions adjacent to each other in the circumferential direction among the plurality of teeth portions. A stator core having a plurality of slots, and an electromagnetic coil provided in the slots, The rotor has a plurality of permanent magnets facing the plurality of teeth portions inside the stator, The plurality of permanent magnets include a first magnet whose magnetic field direction is along the inner side in the radial direction of the yoke portion, a second magnet adjacent to the first magnet and having a magnetic field direction in the clockwise or counterclockwise direction, and a magnetic field adjacent to the first magnet. A third magnet having a direction opposite to that of the second magnet in the clockwise or counterclockwise direction, and two or more combinations of a fourth magnet whose magnetic field direction is along the outer side in the radial direction of the yoke portion adjacent to the third magnet, The position of the inner circumferential side tip surface of the electromagnetic coil is offset from the inner circumferential side tip of the paddle portion toward the yoke portion, Taking the direction orthogonal to the extending direction as the width direction, in each of the plurality of slots, the dimension of the slot in the width direction at the position of the inner circumferential side tip surface of the electromagnetic coil is defined as a first distance, and in the width direction, when the separation distance between the inner circumferential side tip surfaces of the adjacent teeth portions is defined as a second distance, the second distance is 0.5 times or more of the first distance. Rotating electrical machine.

2. The rotating electrical machine according to claim 1, wherein the second distance is smaller than the first distance. Rotating electrical machine.

3. In the rotating electrical machine according to claim 1, the teeth portion has a flange portion located on the inner circumferential side of the stator core rather than the inner circumferential side tip of the paddle portion and having a dimension along the width direction larger than that of the paddle portion, The electromagnetic coil is offset with the inner circumferential side tip surface of the flange portion as a reference point with an offset amount of 5% to 11% of the total length of the teeth portion. Rotating electrical machine.

4. In the rotating electrical machine according to claim 3, when the total length of the teeth portion is 100%, the length of the paddle portion is 96% or more. Rotating electrical machine.

5. The rotating electrical machine according to claim 4, wherein a distance from the inner peripheral side end surface to the outer peripheral side end of the flange portion is 0.2 mm to 2.0 mm.

6. The rotating electrical machine according to any one of claims 1 to 5, wherein when the number of poles is twice the number of sets of the combination of the first magnet to the fourth magnet, the number of poles is an even number of 8 poles or more and 12 poles or less, and the number of teeth is a multiple of 3 of 24 or more and 48 or less.

7. The rotating electrical machine according to claim 6, wherein an outer diameter of the stator core is 100 mm to 200 mm.

8. The rotating electrical machine according to claim 7, wherein a total length of the teeth is 40 mm to 45 mm.

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