Rotor of rotating electric machine and rotating electric machine

Abstract

A rotor (10) of a rotating electric machine is provided with: a shaft (11); a plurality of permanent magnets (12) provided to the outer circumference of the shaft (11) and disposed so as to be away from one another in the circumferential direction; and a rotor coil part (13) that is provided to the outer circumference of the permanent magnets (12), covers the plurality of permanent magnets (12), and has a plurality of rotor coils (3) each including two linear conductors (3a) that are disposed in the axial direction so as to be away from each other in the circumferential direction, and a connection conductor (3b) connecting between the linear conductors (3a). At least one of the two linear conductors (3a) is disposed radially outward of the permanent magnets (12). The rotor coil pitch (τ) is smaller than the pole pitch (W1).

Description

Rotor of rotating electric machine and rotating electric machine

[0001] The present disclosure relates to a rotor for a rotating electric machine in which a permanent magnet is provided on the outer periphery of a rotor core, and to a rotating electric machine.

[0002] Generally, in a high-speed rotating electric machine, when PWM (Pulse Width Modulation) control is performed using an inverter, harmonic magnetic flux of the carrier frequency component is generated, which generates eddy currents in the rotor core and permanent magnets inside the rotor, causing the rotor to heat up. When the rotor heats up, the temperature of the permanent magnets rises, causing demagnetization of the permanent magnets.

[0003] To suppress heat generation in the rotor, a rotor for a rotating electric machine has been proposed in which the rotor core and permanent magnets are surrounded by a highly conductive material that has a higher conductivity than the rotor core and permanent magnets (see, for example, Patent Document 1). In such a rotor for a rotating electric machine, the harmonic magnetic flux of the carrier frequency component generated in the stator is linked with the highly conductive material, thereby reducing the harmonic magnetic flux that reaches the permanent magnets and suppressing demagnetization of the permanent magnets.

[0004] Japanese Patent Application Laid-Open No. 2001-78378

[0005] However, while Patent Document 1 is effective in suppressing eddy current loss caused by harmonics of the carrier frequency component (hereinafter referred to as carrier harmonic loss), there is a problem in that eddy current loss caused by slot harmonics that arise due to permeance fluctuations at the slot openings of the stator (hereinafter referred to as slot harmonic loss) occurs in the highly conductive member.

[0006] The larger the gap between the stator and rotor, the smaller the slot harmonic loss. In rotating electric machines that rotate at high speeds, the gap between the stator and rotor is set large, so slot harmonic loss is smaller than carrier harmonic loss. However, to achieve even higher speeds, the number of turns of the stator winding must be further reduced, which reduces motor inductance and increases carrier harmonic loss. To reduce this, the thickness of the highly conductive member must be increased, but increasing the thickness reduces the gap, which increases slot harmonic loss in the highly conductive member. As such, it was difficult to reduce carrier harmonic loss and slot harmonic loss with the configuration of Patent Document 1, which uses a highly conductive member.

[0007] The present disclosure has been made in consideration of the above, and aims to provide a rotor for a rotating electric machine that can suppress carrier harmonic loss and slot harmonic loss and suppress demagnetization of permanent magnets.

[0008] In order to solve the above-mentioned problems and achieve the object, the rotor of a rotating electric machine in the present disclosure includes a shaft, a plurality of permanent magnets provided on the outer periphery of the shaft and spaced apart in the circumferential direction, and a rotor coil section having a plurality of rotor coils, each including two straight conductors provided on the outer periphery of the permanent magnets and spaced apart in the axial direction in the circumferential direction, and a connecting conductor connecting the straight conductors. At least one of the two straight conductors constituting the rotor coil is arranged radially outward of the permanent magnets. The rotor coil pitch, which is the circumferential angle between the two straight conductors constituting the rotor coil, is smaller than the pole pitch, which is the angle between adjacent permanent magnets.

[0009] The rotor of the rotating electric machine according to the present disclosure has the effect of suppressing carrier harmonic loss and slot harmonic loss, and suppressing demagnetization of the permanent magnets.

[0010] Graph showing the relationship between rotor coil pitch and magnetic flux amount due to slot harmonic magnetic flux in the first embodiment. Graph showing the relationship between adjacent coil pitch and magnetic flux amount due to slot harmonic magnetic flux in the second embodiment. Graph showing the relationship between adjacent coil pitch and magnetic flux amount due to slot harmonic magnetic flux in the second embodiment. Graph showing the relationship between adjacent coil pitch and magnetic flux amount due to slot harmonic magnetic flux in the third embodiment.

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotor for a rotating electric machine and a rotating electric machine according to embodiments will be described in detail below with reference to the accompanying drawings.

[0012] First Embodiment. FIG. 1 is a cross-sectional view showing the configuration of a rotating electric machine 1 according to a first embodiment. FIG. 2 is a cross-sectional view showing the configuration of a rotating electric machine 1 according to the first embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. In FIGS. 1 and 2, the rotating electric machine 1 includes a rotor 10 and a stator 20. The stator 20 has a cylindrical shape surrounding the rotor 10 via a gap 5. The rotor 10 and the stator 20 share a common axis A and are arranged coaxially. In this example, as shown in FIG. 2, the configurations of the rotor 10 and the stator 20 are symmetrical with respect to an orthogonal line B that is orthogonal to the axis A at the center position of the stator 20 in the axial direction A. Hereinafter, the direction of the axis A will be referred to as the axial direction, the direction of the orthogonal line B will be referred to as the radial direction, and the direction centered on the axis A and orthogonal to the orthogonal line B will be referred to as the circumferential direction.

[0013] The stator 20 includes a cylindrical stator core 21 made of a magnetic material and a stator coil 25 provided on the stator core 21. The stator core 21 includes a cylindrical back yoke 22 and a plurality of teeth 23 protruding radially inward from the inner periphery of the back yoke 22. The teeth 23 are spaced apart in the circumferential direction of the rotating electric machine 1. Slots 24, which are spaces that open radially inward of the stator 20, are formed between the teeth 23. The stator coils 25 are wound around the teeth 23 and disposed in the slots 24. As shown in FIG. 2 , the stator coils 25 have coil ends 25a that protrude from the stator core 21 in the axial direction. A current is supplied to the stator coils 25 by PWM control using an inverter (not shown). A rotating magnetic field is generated in the stator 20 when power is supplied to the stator coils 25.

[0014] The rotor 10 is rotatable about an axis A. The rotor 10 also has a shaft 11 as a rotor core, a plurality of permanent magnets 12 provided on the outer periphery of the shaft 11, a cylindrical rotor coil section 13 that collectively surrounds the shaft 11 and the plurality of permanent magnets 12, and a sheet-like holding member 14 that collectively surrounds the shaft 11, the plurality of permanent magnets 12, and the rotor coil section 13.

[0015] The shaft 11 is a cylindrical member having a central axis A. The shaft 11 is made of a magnetic material.

[0016] The multiple permanent magnets 12 are spaced apart from one another around the circumferential direction of the rotor 10. In this example, four permanent magnets 12 are spaced apart from one another around the circumferential direction of the rotor 10. Each permanent magnet 12 is a segment magnet with an arc-shaped cross section that conforms to the outer circumferential surface of the shaft 11. The angle formed by the pole centers, which are the centers of adjacent permanent magnets 12 around the circumferential direction, is called the pole pitch W1. When the total number of permanent magnets 12 is four, the pole pitch W1 (see Figure 3) is 90 degrees. Furthermore, an inter-magnet region 15 exists between adjacent permanent magnets 12 around the circumferential direction. The inter-magnet region 15 may be, for example, air, or an inter-pole member made of a resin material, an iron-based material, or the like. The permanent magnets 12 are, for example, rare earth magnets or ferrite magnets.

[0017] FIG. 3 is a linearly expanded view of the rotor 10 of the rotating electric machine 1 according to the first embodiment. FIG. 3 illustrates the rotor coil section 13, permanent magnets 12, and shaft 11 of the rotor 10. The rotor coil section 13 is provided on the outer periphery of the permanent magnets 12 and is composed of a plurality of rotor coils 3. Each rotor coil 3 is composed of two linear conductors 3a that are spaced apart in the circumferential direction and extend in the axial direction, and a connecting conductor 3b that connects the linear conductors 3a, thereby forming a closed loop. The circumferential angle between the two linear conductors 3a that make up the rotor coil 3 and extend in the axial direction, centered on the axis A, is referred to as the rotor coil pitch τ.

[0018] In the first embodiment, the rotor coil pitch τ is smaller than the aforementioned pole pitch W1. Furthermore, at least one of the two linear conductors 3a extending in the axial direction of each rotor coil 3 faces the outside of the permanent magnet 12 and is located radially outward of the permanent magnet 12. The effects of this configuration will be described later.

[0019] The rotor coil 3 can be made of, for example, copper or aluminum. The rotor coil section 13 is integrally formed, for example, from a single bendable printed circuit board, and the rotor coil section 13 is integrated without being separated. However, as long as the rotor coil section 13 is integrated, a configuration other than a printed circuit board may be used.

[0020] The retaining member 14 overlaps the outer peripheral surface of the rotor coil section 13 and covers the shaft 11, the multiple permanent magnets 12, and the rotor coil section 13 over the entire circumferential direction of the rotor 10. This reinforces the rotor 10 and prevents the permanent magnets 12 from being scattered from the shaft 11 due to centrifugal force when the rotor 10 rotates at high speed. The retaining member 14 is made of a non-magnetic, non-conductive material. Examples of materials that can be used to form the retaining member 14 include carbon fiber reinforced plastics (CFRP) and glass fiber reinforced plastics (GFRP).

[0021] Next, the procedure for assembling the rotor 10 will be described. After attaching a plurality of permanent magnets 12 to the outer periphery of the shaft 11, the cylindrical rotor coil section 13 is inserted around the shaft 11 and the outer periphery of the plurality of permanent magnets 12. This causes the outer periphery of the plurality of permanent magnets 12 to be covered with the rotor coil section 13. After this, a sheet-like holding member 14 is wound around the shaft 11, the plurality of permanent magnets 12, and the rotor coil section 13 from the radially outside. This covers the outer periphery of the rotor coil section 13 with the holding member 14, and the rotor 10 is completed.

[0022] Next, the operation will be described. When current is supplied to the stator coil 25 by PWM control from the inverter, a rotating magnetic field is generated in the stator 20. When a rotating magnetic field is generated in the stator 20, the rotor 10 rotates around the axis A. The current supplied to the stator coil 25 by PWM control contains carrier harmonic components resulting from the carrier frequency. When a current containing carrier harmonic components is supplied to the stator coil 25, carrier harmonic magnetic flux due to the carrier harmonic components is also generated in the stator 20 in addition to the fundamental wave magnetic flux that contributes to torque. Furthermore, the magnetic flux generated by the stator coil 25 passes through the back yoke 22 and teeth 23 and interlinks with the rotor 10. The inner diameter surface of the stator 20 has teeth 23 with high permeance and slots 24 with low permeance arranged intermittently. When the rotor 10 rotates, harmonic magnetic flux generated due to spatial fluctuations in permeance interlinks with the rotor 10.

[0023] Next, the mechanism for suppressing carrier harmonic loss will be explained in comparison with a comparative example. Figure 4 is a diagram showing how carrier harmonic magnetic flux linkages with the rotor 10 of the comparative example. In Figure 4, eddy currents C flowing from the depth of the page to the front side are represented by a black circle within a white circle, and eddy currents C flowing from the front side to the depth side are represented by a white circle with an x ​​within a white circle. The carrier harmonic magnetic flux is harmonic magnetic flux of the carrier frequency component. In the comparative example, the linear conductors 3a of the rotor coil 3 of the rotor coil section 13 are arranged only in the inter-magnet regions 15 near the outer edges of each magnetic pole of the permanent magnet 12, and the linear conductors 3a of the rotor coil 3 of the rotor coil section 13 are not arranged radially outside the permanent magnet 12.

[0024] Carrier harmonic magnetic flux P1 is a carrier high-frequency magnetic flux that is generated in the stator 20 and flows into the rotor 10 from the pole center of the permanent magnet 12. When this carrier harmonic magnetic flux P1 interlinks with the rotor coil section 13, an eddy current C is generated in the rotor coil section 13. When the eddy current C is generated in the rotor coil section 13, a magnetic flux P2 is generated due to the eddy current C. The magnetic flux P2 due to the eddy current C is generated in a direction that cancels out the carrier harmonic magnetic flux P1. This reduces the carrier harmonic magnetic flux P1 that interlinks with the shaft 11 and the permanent magnet 12, thereby reducing heat generation in the shaft 11 and the permanent magnet 12. The rotor coil section 13 generates heat due to the generation of the eddy current C, but because the conductivity of the rotor coil section 13 is higher than that of the permanent magnet 12, the heat generation in the rotor coil section 13 is smaller than the heat generation in the permanent magnet 12 when the carrier harmonic magnetic flux P1 interlinks with the permanent magnet 12. This suppresses heat generation in the rotor 10 as a whole.

[0025] Carrier harmonic magnetic flux P3 is generated in the stator 20 and flows from the inter-magnet region 15 into the rotor 10. In order to cancel out this carrier harmonic magnetic flux P3, eddy currents C must be generated in the rotor coil 3 located radially outside the permanent magnets 12. In the comparative example, the straight conductors 3a of the rotor coil 3 of the rotor coil section 13 are arranged only in the inter-magnet region 15, so the carrier harmonic magnetic flux P3 flowing from the inter-magnet region 15 into the rotor 10 cannot be canceled out, and eddy currents C are generated by the carrier harmonic magnetic flux P3 in the inter-pole member and shaft 11 arranged in the inter-magnet region 15, resulting in an insufficient effect in reducing carrier harmonic loss.

[0026] 5 is a diagram showing how carrier harmonic magnetic flux links with rotor 10 of embodiment 1. In Fig. 5 as well, eddy currents C flowing from the depth of the page to the front side are represented by symbols with black circles within white circles, and eddy currents C flowing from the front side of the page to the depth side are represented by symbols with x's within white circles. In embodiment 1, conductors are arranged not only in inter-magnet region 15 but also on the radially outer side of permanent magnets 12, which has the effect of canceling out not only carrier harmonic magnetic flux P1 flowing into rotor 10 from the pole center, but also carrier harmonic magnetic flux P3 flowing into rotor 10 from inter-magnet region 15, which is the inter-pole region, and a sufficient carrier harmonic loss reduction effect is obtained.

[0027] Next, the mechanism for suppressing slot harmonic loss according to the first embodiment will be described in comparison with a comparative example.

[0028] In the comparative example, when the number of poles of the permanent magnet 12 is P, the circumferential angle is θ, the rotational angular velocity is ω, and the time is t, the distribution of the magnetomotive force F by the permanent magnet 12 is expressed by the formula (1). ０ is the maximum value of the electromotive force F.

[0029] Next, the permeance P has a component that does not vary with respect to the circumferential position and a component that varies depending on the slots 24 of the stator 20. If the number of slots is N, this is expressed as in equation (2). P ０ is the maximum value of the permeance P.

[0030] The magnetic flux density B in the gap 5 is the product of the magnetomotive force F and the permeance P, and is expressed as in equation (3).

[0031] In equation (3), the first term is the fundamental wave magnetic flux, and the second and third terms are the slot harmonic magnetic flux. Equation (3) is expressed in the stator coordinate system, and when this is converted into an expression in the rotor coordinate system, it becomes equation (4).

[0032] The fundamental magnetic flux of the first term does not fluctuate over time in the rotor coordinate system and is therefore not a factor in generating eddy currents, but the slot harmonics of the second and third terms fluctuate over time in the rotor coordinate system. As a result, eddy currents flow in the rotor 10 to cancel out these time fluctuations. If a conductive member is provided near the gap 5, very large eddy current loss will occur.

[0033] Next, a first embodiment will be described. In the first embodiment, the straight conductors 3a of the rotor coils 3 of the rotor coil section 13 are provided outside the permanent magnets 12. With regard to the amount of magnetic flux linking each rotor coil 3, the magnetic flux Φ due to the slot harmonic component in the second term of equation (4) is expressed as equation (5) when the axial length of the permanent magnets 12 is L, and its amplitude depends on sin((N+P / 2)τ / 2).

[0034] Similarly, the magnetic flux Φ due to the slot harmonic component in the third term of equation (4) is expressed as equation (6), and its amplitude depends on sin((N−P / 2)τ / 2).

[0035] FIG. 6 is a graph showing the relationship between the rotor coil pitch τ and the amount of magnetic flux due to slot harmonic magnetic flux in the first embodiment. FIG. 6 shows the results of plotting both sin((N+P / 2)τ / 2) and sin((N-P / 2)τ / 2) against the rotor coil pitch τ. In FIG. 6, the number of poles P is 4 and the number of slots N is 24. Since the pole pitch is 90 degrees (=360 / 4), when the rotor coil pitch τ is the same as the pole pitch, both are 1, and there is no effect of reducing the slot harmonic magnetic flux. On the other hand, by making the rotor coil pitch τ smaller than the pole pitch (=90 degrees), both are smaller than 1. Eddy current loss occurs in the rotor coil 3 depending on the fluctuations in the amount of magnetic flux linking the rotor coil 3. Therefore, by making the rotor coil pitch τ smaller than the pole pitch, the amount of magnetic flux linking the rotor coil 3 can be reduced, thereby reducing eddy current loss.

[0036] Furthermore, according to equation (5), the rotor coil pitch τ1 at which the amount of interlinkage magnetic flux due to the slot harmonic component in the second term of equation (4) is minimized is given by equation (7).

[0037] Furthermore, according to equation (6), the rotor coil pitch τ2 at which the amount of interlinkage magnetic flux due to the slot harmonic component of the third term in equation (4) is minimized is given by equation (8).

[0038] Therefore, by setting the rotor coil pitch τ to τ2<τ<τ1 as in equation (9), it is possible to further reduce the eddy current loss due to slot harmonics.

[0039] As described above, according to the first embodiment, at least one of the two straight conductors 3a constituting the rotor coil 3 is disposed radially outside the permanent magnet 12, and the rotor coil pitch τ is smaller than the pole pitch W1, which not only reduces carrier harmonic loss generated in the permanent magnet 12 but also suppresses slot harmonic loss in the rotor coil 3. As a result, demagnetization of the permanent magnet 12 can be suppressed.

[0040] Second Embodiment Fig. 7 is a linearly expanded view of the rotor 10 of a rotating electric machine 1 according to the second embodiment. In the second embodiment, the rotor coil section 13 is composed of a plurality of rotor coil groups 13a, 13b, .... Two rotor coil groups 13a, 13b are shown in Fig. 7. Each rotor coil group 13a, 13b is composed of a plurality of rotor coils 3 connected in series. As in the first embodiment, each rotor coil 3 is composed of two linear conductors 3a extending in the axial direction and a connecting conductor 3b connecting the linear conductors 3a.

[0041] In the second embodiment, similarly to the first embodiment, the rotor coil pitch τ of each rotor coil 3 is smaller than the pole pitch W1. In addition, at least one of the two linear conductors 3 a extending in the axial direction of each rotor coil 3 is located radially outside the permanent magnets 12.

[0042] Furthermore, in the second embodiment, the linear conductors 3a of the rotor coils 3 constituting one rotor coil group 13a, 13b are arranged so that the circumferential center positions of the linear conductors 3a are different from each other. The circumferential distance between adjacent rotor coils 3 constituting one rotor coil group 13a, 13b is referred to as the adjacent coil pitch α. In each rotor coil group 13a, 13b, the end of one rotor coil 3 is connected to the beginning of the next rotor coil 3, the end of the next rotor coil 3 is connected to the beginning of the next rotor coil 3, and the end of the next rotor coil 3 is connected to the beginning of the next rotor coil 3. This connection of the end of one rotor coil 3 to the beginning of another rotor coil 3 is referred to as being connected in series. That is, the rotor coil groups 13a, 13b in FIG. 7 are configured by connecting a plurality of rotor coils 3 in series. With this configuration, the magnetic fluxes due to the slot harmonics that link with each rotor coil 3 cancel each other out, thereby reducing eddy current loss due to the slot harmonic magnetic flux generated in the rotor coil section 13.

[0043] The principle will be explained below using mathematical expressions. When the adjacent coil pitch is α, the total amount of magnetic flux due to the slot harmonic component of the second term of equation (4) that interlinks the three rotor coils 3 of one rotor coil group 13a, 13b is Φ all is expressed as in equation (10).

[0044] When formula (10) is calculated, the calculation result is as shown in formula (11).

[0045] FIG. 8 is a graph showing the relationship between the adjacent coil pitch α and the amount of magnetic flux due to slot harmonic magnetic flux in the second embodiment. FIG. 8 shows the results of plotting (1 + 2 cos((N + P / 2)α))) / 3 in equation (11) and (1 + 2 cos((N - P / 2)α))) / 3 obtained by similarly calculating the slot harmonic component of the third term in equation (4) against the adjacent coil pitch α. When the adjacent coil pitch α = 0, both are 1, and there is no effect of reducing the slot harmonic magnetic flux. On the other hand, by making the adjacent coil pitch α greater than 0, both become smaller than 1. Eddy current loss occurs in the rotor coil 3 depending on the total amount of magnetic flux linking the rotor coil groups 13a and 13b of the rotor coil section 13. Therefore, by making the adjacent coil pitch α greater than 0, the eddy current loss generated in the rotor coil section 13 can be reduced.

[0046] In FIG. 7, three rotor coils 3 are connected to each of the rotor coil groups 13a and 13b. However, if the rotor coil groups 13a and 13b are each made up of two or more rotor coils 3 and the circumferential positions of the rotor coils 3 are different, i.e., if the adjacent coil pitch α is greater than 0, the effect of reducing eddy current loss due to slot harmonic magnetic flux generated in the rotor coil section 13 can be similarly obtained.

[0047] Thus, according to the second embodiment, the rotor coil section 13 includes rotor coil groups 13a and 13b in which a plurality of rotor coils 3 are connected in series, and the circumferential center positions of the plurality of rotor coils 3 constituting the rotor coil groups 13a and 13b are different from each other, so that the eddy current loss generated in the rotor coil section 13 can be further reduced.

[0048] Third Embodiment Fig. 9 is a linearly developed view of the rotor 10 of a rotating electric machine 1 according to a third embodiment. The rotor coil section 13 of the third embodiment is provided on the outer periphery of the permanent magnets 12 and is composed of a plurality of rotor coils 3. Fig. 9 illustrates one rotor coil 3 extracted from the plurality of rotor coils 3 of the rotor coil section 13. Each rotor coil 3 is composed of two linear conductors 3a extending in the axial direction and a connecting conductor 3b connecting the linear conductors 3a.

[0049] In the third embodiment, similarly to the first embodiment, the rotor coil pitch τ of each rotor coil 3 is smaller than the pole pitch W1. In addition, at least one of the two linear conductors 3 a extending in the axial direction of each rotor coil 3 is located radially outside the permanent magnets 12.

[0050] Furthermore, in the third embodiment, the two straight conductors 3 a are arranged not parallel to the axial direction but tilted in the circumferential direction. Here, the angle of the straight conductors 3 a with respect to the axial direction is called the coil skew angle β. By making the coil skew angle β larger than 0 degrees, it is possible to reduce the magnetic flux due to slot harmonics that interlinks with the rotor coil 3, and to reduce eddy current loss due to slot harmonic magnetic flux generated in the rotor coil section 13.

[0051] The principle will be explained below using mathematical expressions. The magnetic flux Φ due to the slot harmonic component, which is the second term in expression (4), is expressed as expression (12).

[0052] FIG. 10 is a graph showing the relationship between the coil skew angle β and the amount of magnetic flux due to slot harmonic magnetic flux in the third embodiment. FIG. 10 shows the results of plotting both sin((N+P / 2)β) / (N+P / 2)β in equation (12) and sin((N-P / 2)β) / (N-P / 2)β, which is obtained by similarly calculating the slot harmonic component in the third term of equation (4), against the coil skew angle β. When the coil skew angle β = 0, both are 1, and there is no effect of reducing the slot harmonic magnetic flux. On the other hand, by increasing the coil skew angle β beyond 0, both become less than 1. Eddy current loss occurs in the rotor coil 3 depending on the total amount of magnetic flux linking the rotor coil 3. Therefore, by increasing the coil skew angle β beyond 0, the eddy current loss generated in the rotor coil section 13 can be reduced.

[0053] Thus, according to embodiment 3, the straight conductors 3a constituting the rotor coil 3 are arranged at an inclination in the circumferential direction with respect to the axial direction, thereby further reducing the eddy current loss generated in the rotor coil portion 13.

[0054] The configurations shown in the above embodiments are examples of the contents of the present disclosure, and may be combined with other known technologies, and parts of the configurations may be omitted or modified within the scope of the gist of the present disclosure.

[0055] 1 Rotating electric machine, 3 Rotor coil, 3a Straight conductor, 3b Connecting conductor, 5 Gap, 10 Rotor, 11 Shaft, 12 Permanent magnet, 13 Rotor coil section, 13a, 13b Rotor coil group, 14 Holding member, 15 Inter-magnet area, 20 Stator, 21 Stator core, 22 Back yoke, 23 Teeth, 24 Slot, 25 Stator coil, 25a Coil end, W1 Pole pitch, α Adjacent coil pitch, β Coil skew angle, τ, τ1, τ2 Rotor coil pitch.

Claims

1. A shaft, A plurality of permanent magnets are provided on an outer periphery of the shaft and are spaced apart from one another in a circumferential direction; a rotor coil section that has a plurality of rotor coils, each of which includes two straight conductors that are provided on the outer periphery of the permanent magnets and arranged axially and circumferentially apart, and a connecting conductor that connects the straight conductors, and covers the plurality of permanent magnets; At least one of the two linear conductors constituting the rotor coil is disposed radially outside a permanent magnet, The rotor coil pitch, which is the circumferential angle between the two straight conductors of the coil that constitutes the rotor coil, is smaller than the pole pitch, which is the angle between adjacent permanent magnets. A rotor for a rotating electric machine comprising:

2. The rotor coil unit includes a rotor coil group in which a plurality of the rotor coils are connected in series, and the circumferential center positions of the plurality of the rotor coils constituting the rotor coil group are different from each other.

2. The rotor of claim 1, wherein the rotor is a rotatable rotor.

3. The linear conductors constituting the rotor coil are arranged at an inclination in the circumferential direction with respect to the axial direction.

2. The rotor of claim 1, wherein the rotor is a rotatable rotor.

4. The rotor coil section is formed on one substrate.

2. The rotor of claim 1, wherein the rotor is a rotatable rotor.

5. A rotor for a rotating electric machine according to any one of claims 1 to 4; a stator surrounding the rotor via a gap; A rotating electric machine characterized by:

6. When the number of slots of the stator is N, the number of poles is P, and the rotor coil pitch of the two straight conductors of the rotor coil is τ, τ is expressed by the following formula: [0010] Fulfill 6. The rotating electric machine according to claim 5.

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