Rotating electric machine and rotating electric machine system

Abstract

The rotating electric machine (101) includes a rotor (1) rotatable about an axis (CA), a stator (2), a housing (3) that accommodates the rotor and the stator, and a plurality of bearings (4A, 4B) that rotatably support the rotor relative to the housing. The rotor includes a shaft (10), a rotor core (11) connected to the shaft, and a rotor winding (12) wound around the rotor core. The stator includes a stator core (21) connected to the housing, and a stator winding (22). The rotating electric machine further includes at least one electrostatic shield (5) having a portion disposed between the rotor and the stator in a radial direction relative to the axis. The at least one electrostatic shield is provided with a plurality of communication holes (50). The at least one electrostatic shield is electrically connected to either the stator core or the housing.

Description

[Technical field]

[0001] The present disclosure relates to a rotating electric machine and a rotating electric machine system. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 01-144356 (Patent Document 1) describes a superconducting rotating machine in which the rotor's field winding is made of superconducting wire. The superconducting rotating machine is provided so that the rotor and stator are cooled using a refrigerant that has higher insulating properties than gaseous helium at room temperature. The rotating shaft of the rotor is rotatably supported by a bearing on the stator frame. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 01-144356 Summary of the Invention [Problem to be solved by the invention]

[0004] In the rotating electric machine, stray capacitance occurs between the rotor and the stator core and between the stator winding. This causes a potential difference between the rotating shaft and the stator frame, which in turn causes a potential difference between the inner and outer rings of the bearing. This causes electrical stress to be applied to the bearing, which may cause damage to the bearing.

[0005] A primary object of the present disclosure is to provide a rotating electric machine that can reduce the risk of damage to the bearings while achieving cooling for both the rotor and the stator. [Means for solving the problem]

[0006] The rotating electric machine according to the present disclosure includes a rotor rotatable around an axis, a stator, a housing that accommodates the rotor and the stator, and a plurality of bearings that rotatably support the rotor with respect to the housing. The rotor includes a shaft, a rotor core connected to the shaft, and a rotor winding wound around the rotor core. The stator includes a stator core connected to the housing, and a stator winding. The rotating electric machine further includes at least one electrostatic shield having a portion disposed between the rotor and the stator in a radial direction relative to the axis. The at least one electrostatic shield includes a plurality of communication holes that communicate a first space located on the rotor side of the at least one electrostatic shield in the radial direction with a second space located on the opposite side of the rotor with respect to the at least one electrostatic shield in the radial direction. The plurality of bearings include an inner ring electrically connected to the shaft and an outer ring electrically connected to the housing. The at least one electrostatic shield is electrically connected to either the stator core or the housing.

[0007] A rotating electric machine system according to the present disclosure includes the rotating electric machine described above, a supply unit for supplying the cooling medium to the first flow passage, and a recovery unit for recovering the cooling medium from the second flow passage. Effect of the Invention

[0008] According to the present disclosure, it is possible to achieve cooling of both the rotor and the stator while reducing the risk of damage to the bearings. [Brief description of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a rotating electric machine and a rotating electric machine system according to a first embodiment. [Diagram 2] 2 is a partially enlarged cross-sectional view showing a rotor, a stator, and an electrostatic shield of the rotating electric machine according to the first embodiment. FIG. [Diagram 3] 11 is a cross-sectional view showing a rotating electric machine and a rotating electric machine system according to a second embodiment. FIG. [Figure 4]FIG. 11 is a cross-sectional view showing a rotating electric machine and a rotating electric machine system according to a third embodiment. [Diagram 5] 11 is a partially enlarged cross-sectional view showing a rotor, a stator, and an electrostatic shield of a rotating electric machine according to a third embodiment. FIG. [Figure 6] FIG. 11 is a cross-sectional view showing a rotating electric machine according to a fourth embodiment. [Figure 7] 11 is a partially enlarged cross-sectional view showing a rotor, a stator, and an electrostatic shield of a rotating electric machine according to a fourth embodiment. FIG. [Figure 8] FIG. 4 is a cross-sectional view showing an example of a combination of rotating electric machines according to the first to fourth embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following, the same or corresponding parts are denoted by the same reference characters, and overlapping descriptions will not be repeated.

[0011] Embodiment 1 <Configuration of rotating electric machine> The rotating electric machine according to the first embodiment is a superconducting rotating electric machine. As shown in FIG 1, the rotating electric machine 101 according to the first embodiment includes a rotor 1, a stator 2, a housing 3, a pair of bearings 4, an electrostatic shield 5, and a magnetic shield 6.

[0012] The rotor 1 is rotatable around an axis CA. Hereinafter, the radial direction and the circumferential direction with respect to the axis CA of the rotor 1 will be simply referred to as the radial direction and the circumferential direction. The rotor 1 is disposed, for example, such that the axis CA is aligned horizontally. Note that FIG. 1 is a cross-sectional view taken along the axis CA.

[0013] The rotor 1 has a shaft 10, a rotor core 11, a rotor winding 12, a low-temperature damper 15, and a room-temperature damper 16. The rotor winding 12 is a superconducting winding. The low-temperature damper 15 is provided on the inside of the room-temperature damper 16 in the above-mentioned radial direction. The rotor core 11 and the rotor winding 12 are provided on the inside of the low-temperature damper 15 in the above-mentioned radial direction. The rotor 1 has an outer peripheral surface 13 that faces a stator core 21 of the stator 2 described later in the above-mentioned radial direction. The outer peripheral surface 13 is, for example, the outer peripheral surface of the room-temperature damper 16.

[0014] The shaft 10 extends along the axis CA. The shaft 10 has a first shaft 10A and a second shaft 10B. The first shaft 10A and the second shaft 10B are arranged on the axis CA at a distance from each other. The first shaft 10A extends from the rotor core 11 to one side in the extension direction of the axis CA. The second shaft 10B extends from the rotor core 11 to the other side in the extension direction of the axis CA.

[0015] The rotor core 11 is a rotor core made of, for example, a magnetic material. The rotor core 11 may be made of, for example, a non-magnetic material such as stainless steel (SUS).

[0016] The rotor winding 12 is wound around the rotor core 11. The rotor winding 12 may be a so-called low-temperature superconducting winding. Preferably, the rotor winding 12 is a high-temperature superconducting winding whose superconducting transition temperature is equal to or higher than the liquefaction temperature of nitrogen gas (77 K).

[0017] The rotor 1 is provided with a plurality of slots 14 that accommodate a portion of the rotor winding 12. The plurality of slots 14 are arranged at intervals in the circumferential direction. Each of the plurality of slots 14 is provided on the inner side of the low-temperature damper 15 in the radial direction.

[0018] The low temperature damper 15 communicates with the normal temperature damper 16 through a communication hole (not shown). The room temperature damper 16 forms an outer shell of the rotor 1. The room temperature damper 16 is electrically connected to the shaft 10. The room temperature damper 16 has, for example, the same potential as the shaft 10. Each of the first shaft 10A and the second shaft 10B has the same potential as the room temperature damper.

[0019] The rotor 1 has a structure for supplying a cooling medium to the rotor windings 12 and a structure for discharging the cooling medium supplied to the rotor windings 12 to the outside of the rotor 1. The details of the structure will be described later.

[0020] The stator 2 is fixed to the housing 3. The stator 2 is disposed outward of the rotor winding 12 in the radial direction. The stator 2 surrounds the entire circumference of the rotor winding 12 in the circumferential direction. The stator 2 has a stator core 21 and a stator winding 22.

[0021] The stator core 21 is electrically connected to the housing 3. The stator core 21 has an inner circumferential surface 23 that faces the outer circumferential surface 13 of the rotor core 11 in the radial direction. An air gap is provided between the inner circumferential surface 23 of the stator core 21 and the outer circumferential surface 13 of the rotor core 11.

[0022] The stator core 21 is provided with a plurality of slots 24 that accommodate parts of the stator windings 22. The plurality of slots 24 are arranged at intervals from one another in the circumferential direction. Each of the plurality of slots 24 has an opening 24A (see FIG. 2) that opens to the inner circumferential surface 23, for example.

[0023] The stator winding 22 is wound around the stator core 21. The stator winding 22 has a plurality of first portions 22A accommodated in each of the plurality of slots 24 of the stator core 21, and a plurality of second portions 22B protruding outward from the stator core 21 in the direction in which the axis CA extends. Each of the second portions 22B is a portion that connects between two first portions 22A accommodated in each of two slots 24 adjacent to each other in the circumferential direction, that is, a so-called coil end. The entire stator winding 22 is disposed outside the inner circumferential surface 23 of the stator core 21. The stator winding 22 is, for example, a normal conducting winding. The stator winding 22 may be a superconducting winding.

[0024] The housing 3 accommodates the rotor 1 and the stator 2. The housing 3 has a first wall portion 3A and a second wall portion 3B facing each other in the extending direction of the axis CA, and a third wall portion 3C connecting the first wall portion 3A and the second wall portion 3B. The first shaft 10A has a portion disposed outside the first wall portion 3A. The second shaft 10B has a portion disposed outside the second wall portion 3B. The stator 2 is fixed to the third wall portion 3C via a magnetic shield 6. The stator core 21 is electrically connected to the third wall portion 3C. The first wall portion 3A and the second wall portion 3B are, for example, at the same potential as the stator core 21.

[0025] The housing 3 has a structure for discharging the cooling medium to the outside, the details of which will be described later.

[0026] The pair of bearings 4 includes a first bearing 4A that rotatably supports the first shaft 10A and a second bearing 4B that rotatably supports the second shaft 10B. The first bearing 4A and the second bearing 4B are, for example, rolling bearings. The first bearing 4A includes an inner ring connected to the first shaft 10A, an outer ring connected to the first wall portion 3A of the housing 3, and a rolling element. The second bearing 4B includes an inner ring connected to the second shaft 10B, an outer ring connected to the second wall portion 3B of the housing 3, and a rolling element. In the first bearing 4A and the second bearing 4B, lubricating oil is supplied between the inner ring, the outer ring, and the rolling element.

[0027] The outer ring of the first bearing 4A is electrically connected to the stator core 21 via the first wall portion 3A and the third wall portion 3C. The inner ring of the first bearing 4A is electrically connected to the first shaft 10A. The outer ring of the second bearing 4B is electrically connected to the stator core 21 via the second wall portion 3B and the third wall portion 3C. The inner ring of the second bearing 4B is electrically connected to the second shaft 10B. In each of the first bearing 4A and the second bearing 4B, the potential difference between the inner ring and the outer ring is equal to the potential difference between the room temperature damper of the rotor 1 and the stator core 21.

[0028] The electrostatic shield 5 has a portion that is disposed between the rotor 1 and the stator 2 in the radial direction. The portion of the electrostatic shield 5 is disposed in the gap between the outer circumferential surface 13 of the room temperature damper 16 and the inner circumferential surface 23 of the stator core 21. The electrostatic shield 5 is disposed at a distance from each of the outer circumferential surface 13 of the room temperature damper 16 and the inner circumferential surface 23 of the stator core 21 in the radial direction. The electrostatic shield 5 is disposed at a distance from each of the multiple first portions and the multiple second portions of the stator winding 22 in the radial direction.

[0029] The electrostatic shield 5 is electrically connected to the housing 3. The electrostatic shield 5 is fixed to the housing 3. The electrostatic shield 5 is stretched between the first wall portion 3A and the second wall portion 3B. The electrostatic shield 5 has one end electrically connected to the first wall portion 3A and the other end electrically connected to the second wall portion 3B. The one end of the electrostatic shield 5 is fixed to the first wall portion 3A. The other end of the electrostatic shield 5 is fixed to the second wall portion 3B. The electrostatic shield 5 has the same potential as the first wall portion 3A and the second wall portion 3B.

[0030] Hereinafter, the space inside the housing 3 that is located closer to the rotor 1 than the electrostatic shield 5 in the radial direction is referred to as a first space S1. The space inside the housing 3 that is located on the opposite side of the electrostatic shield 5 from the rotor 1 in the radial direction is referred to as a second space S2. The electrostatic shield 5 is provided with a plurality of communication holes 50 that communicate the first space S1 with the second space S2. The communication holes 50 are arranged at intervals from each other in the direction in which the axis CA extends and in the circumferential direction. Each of the communication holes 50 is, for example, a through hole that penetrates the electrostatic shield 5 in the radial direction. Each of the communication holes 50 is arranged at intervals from each of the outer circumferential surface 13 of the room temperature damper 16 and the inner circumferential surface 23 of the stator core 21 in the radial direction. The number of the communication holes 50 may be any number.

[0031] The material constituting the electrostatic shield 5 includes a non-magnetic material having electrical conductivity. The material constituting the electrostatic shield 5 includes, for example, at least one of Cu and aluminum (Al). The electrostatic shield 5 may have a main body made of resin and a conductive film covering the surface of the main body. In this case, it is sufficient that the conductive film is made of a non-magnetic material having electrical conductivity. There is no particular limitation on the method of forming the conductive film. The conductive film may be a plating film. The electrostatic shield 5 may be a single member made of a non-magnetic material having electrical conductivity. The electrostatic shield 5 is, for example, an annular member.

[0032] The magnetic shield 6 is disposed radially outward of the stator 2 in the housing 3. The magnetic shield 6 is disposed radially between the stator 2 and the third wall portion 3C of the housing 3. The magnetic shield 6 reduces magnetic flux leaking from the inside of the rotating electric machine 101 to the outside.

[0033] 2 is a partially enlarged cross-sectional view showing the rotor 1, the stator 2, and the electrostatic shield 5 of the rotating electric machine 101 in a cross section perpendicular to the axis CA. Note that the illustration of the inside of the rotor 1 is simplified in Fig. 2 compared to Fig. 1. As shown in Fig. 2, the stator core 21 has a back yoke 25, a plurality of teeth 26, and a plurality of flanges 27.

[0034] The back yoke 25 has a cylindrical shape. The back yoke 25 is connected to the magnetic shield 6.

[0035] The teeth 26 protrude from the back yoke 25 towards the rotor 1. The teeth 26 are spaced apart from one another in the circumferential direction. The slots 24 are formed between the teeth 26 in the circumferential direction. The stator winding 22 is wound around each of the teeth 26.

[0036] The flanges 27 protrude in the circumferential direction from the radial inner circumferential ends of each of the teeth 26. A pair of flanges 27 protruding from the inner circumferential ends of two teeth 26 adjacent to each other in the circumferential direction are disposed at a distance from each other in the circumferential direction. The opening 24A of each of the slots 24 is formed between the pair of flanges 27.

[0037] The electrostatic shield 5 is disposed so as to overlap, in the radial direction, with the openings 24A of the plurality of slots 24. Note that the communication holes 50 may be disposed so as to overlap, in the radial direction, with the openings 24A of the plurality of slots 24.

[0038] Next, with reference to FIG. 1, a structural example of rotor 1 for supplying a cooling medium to rotor windings 12 will be described.

[0039] The rotor 1 is provided with a first flow path F1 through which the cooling medium flows from the outside of the housing 3 through the rotor winding 12 to the first space. The first flow path F1 has an inlet I1 through which the cooling medium flows in and a plurality of outlets O1 through which the cooling medium flows out. The inlet I1 is connected to a supply unit 111 (described later) outside the housing 3. Each of the plurality of outlets O1 opens onto the outer circumferential surface 13 of the room temperature damper 16.

[0040] The first flow path F1 has, for example, a third flow path F3, a plurality of fourth flow paths F4, a plurality of slots 14, and a plurality of fifth flow paths F5. The third flow path F3, the plurality of fourth flow paths F4, the plurality of slots 14, and the plurality of fifth flow paths F5 are connected in series with each other. The third flow path F3 has an inlet I1. Each of the plurality of fifth flow paths F5 has an outlet O1.

[0041] The third flow passage F3 extends along the axis CA. The third flow passage F3 is provided inside the first shaft 10A and the rotor core 11. The third flow passage F3 is disposed inside the rotor core 11, more inward than the rotor windings 12.

[0042] Each of the multiple fourth flow paths F4 extends along the radial direction. Each of the multiple fourth flow paths F4 is provided inside the rotor core 11, radially inward of the rotor windings 12. Each of the multiple fourth flow paths F4 is connected to the third flow path F3. Each of the multiple fourth flow paths F4 communicates between the third flow path F3 and each of the multiple slots 14. Each of the multiple fourth flow paths F4 is disposed at intervals from one another in the circumferential direction and in the direction in which the axis CA extends.

[0043] Each of the plurality of fifth flow paths F5 extends along the radial direction. Each of the plurality of fifth flow paths F5 is provided inside the rotor core 11, outside the rotor winding 12 in the radial direction. Each of the plurality of fifth flow paths F5 is connected to at least one of the plurality of fourth flow paths F4 via the plurality of slots 14. Each of the plurality of fifth flow paths F5 communicates between each of the plurality of slots 14 and the outer circumferential surface 13 of the room temperature damper 16. Each of the plurality of fifth flow paths F5 is disposed at intervals from one another in the circumferential direction and in the extending direction of the axis CA.

[0044] The third flow passage F3 may be formed by a tube inserted through the first shaft 10A and a container capable of storing a cooling medium that is provided inside the rotor core 11. Each of the multiple fourth flow passages F4 and the multiple fifth flow passages F5 may be formed by a tube provided inside the rotor core 11, for example.

[0045] Small gaps through which the cooling medium can flow exist between adjacent wires in the rotor winding 12. The cooling medium that flows from each of the fourth flow paths F4 into each of the slots 14 passes through the gaps that exist between adjacent wires in the rotor winding 12, and flows out into each of the fifth flow paths F5.

[0046] The cooling medium flowing through the first flow path F1 cools the rotor winding 12 and then flows out into the first space S1. The cooling medium that has flowed out into the first space S1 passes through a plurality of communication holes 50 provided in the electrostatic shield 5 and flows into the second space S2.

[0047] Next, with reference to FIG. 1, a structural example of the housing 3 for discharging the cooling medium to the outside of the rotating electrical machine 101 will be described.

[0048] The housing 3 is provided with a second flow passage F2 for the cooling medium to flow out from the second space S2 to the outside of the housing. The second flow passage F2 has an inlet I2 through which the cooling medium flows in and an outlet O2 through which the cooling medium flows out. The inlet I2 opens into the second space S2 of the housing 3. The inlet I2 is disposed, for example, outside the stator 2 in the radial direction and outside the stator 2 in the extending direction of the axis CA. The inlet I2 may be disposed at the lowest position in the direction of gravity in the housing 3. The cooling medium in a liquefied state can be efficiently collected by such a second flow passage F2. The inlet I2 may be disposed at the highest position in the direction of gravity in the housing 3. The cooling medium in a vaporized state can be efficiently collected by such a second flow passage F2. The inlet I2 opens into, for example, a space portion located at the top of the second space S2. The outlet O2 is connected to a collection unit 121 described later outside the housing 3.

[0049] The second flow passage F2 is disposed, for example, on the opposite side of the stator 2 to the load in the extending direction of the axis CA.

[0050] <Configuration of rotating electrical machine system> 1, a rotating electric machine system 201 according to the first embodiment mainly includes a rotating electric machine 101 according to the first embodiment, a supply unit 111, and a recovery unit 121. In the rotating electric machine system 201, the rotating electric machine 101, the supply unit 111, and the recovery unit 121 are included in, for example, a circuit in which at least a portion of the cooling medium circulates.

[0051] The supply unit 111 supplies the cooling medium to the rotating electric machine 101. The supply unit 111 is connected to the inlet I1 of the first flow path F1. Preferably, the supply unit 111 supplies the cooling medium in a liquid phase to the rotating electric machine 101. The supply unit 111 has, for example, a pump for feeding the cooling medium.

[0052] The recovery unit 121 recovers the cooling medium from the rotating electric machine 101. The recovery unit 121 recovers, for example, a gas-phase cooling medium from the rotating electric machine 101. The recovery unit 121 has, for example, a pump.

[0053] The rotating electric machine system 201 includes, for example, a cooling unit 131 and a storage unit 141. In the rotating electric machine system 201, the cooling unit 131 and the storage unit 141 are included in the above-mentioned circuit.

[0054] The cooling unit 131 cools the cooling medium recovered from the rotating electric machine 101 by the recovery unit 121. The cooling unit 131 is, for example, a condensation unit that condenses the gas phase cooling medium into a liquid phase cooling medium. The cooling unit 131 is, for example, a heat exchanger. The storage unit 141 stores the cooling medium. The storage unit 141 stores, for example, the liquid phase cooling medium condensed by the cooling unit 131.

[0055] The cooling medium is not particularly limited as long as it can appropriately cool the rotor winding 12. When the rotor winding 12 is a low-temperature superconducting winding, the cooling medium is, for example, liquid helium. When the rotor winding 12 is a high-temperature superconducting winding, the cooling medium is, for example, liquid nitrogen. The temperature of the cooling medium supplied to the rotor winding 12 is equal to or lower than the transposition temperature of the superconducting winding. The evaporation temperature of the cooling medium is higher than the transposition temperature of the superconducting winding.

[0056] In the rotating electric machine system 201, the shaft 10 is connected to a load (not shown) on the second shaft 10B side. The turbine is provided to rotate around an axis CA together with the shaft 10. Note that examples of the load of the rotating electric machine system 201 include a gear and a power mechanism.

[0057] <effect> The rotating electric machine 101 includes an electrostatic shield 5 having a portion disposed between the rotor 1 and the stator winding 22 in the radial direction and electrically connected to the housing 3. Compared to a rotating electric machine not including the electrostatic shield 5, the electrostatic shield 5 reduces the stray capacitance between the rotor 1 and the stator winding 22 and reduces the potential difference between the inner ring and the outer ring of each of the first bearing 4A and the second bearing 4B. As a result, the risk of damage to each of the first bearing 4A and the second bearing 4B in the rotating electric machine 101 can be reduced compared to the risk of damage to the bearings in a conventional rotating electric machine.

[0058] The electrostatic shield 5 of the rotating electric machine 101 is provided with a plurality of communication holes 50 that communicate the first space S1 and the second space S2. The plurality of communication holes 50 can prevent heat generated in the rotor 1 from being stored in the first space S1 and prevent heat generated in the stator 2 from being stored in the second space S2. When the cooling medium is supplied into the housing 3 as described above, the plurality of communication holes 50 can prevent the cooling medium from stagnating in each of the first space S1 and the second space S2. When the cooling medium is supplied to the first space S1 as described above, the cooling medium can flow from the first space S1 through the plurality of communication holes 50 into the second space S2. As a result, according to the rotating electric machine 101, the electrostatic shield 5 can efficiently cool each of the rotor 1 and the stator 2 while reducing the risk of damage to each of the first bearing 4A and the second bearing 4B.

[0059] In the rotating electric machine 101, the rotor 1 has the rotor winding 12, so that the amount of magnetic flux of the rotor 1 can be adjusted according to the amount of current flowing through the rotor winding 12. In the rotating electric machine 101, a superconducting winding is used as the rotor winding 12. Therefore, if the temperature of the cooling medium supplied to the rotor winding 12 is set to a superconducting transition temperature or lower, the rotor winding 12 can be efficiently maintained in a superconducting state. The stator 2 can be cooled by the cooling medium used to cool the rotor winding 12. According to the rotating electric machine 101, while reducing the risk of damage to each of the first bearing 4A and the second bearing 4B by the electrostatic shield 5, the cooling performance for the rotor 1 can be made equal to or higher than the cooling performance required for the rotor of a superconducting rotating electric machine.

[0060] In the rotating electric machine 101, the electrostatic shield 5 is electrically connected to each of the first wall portion 3A and the second wall portion 3B of the housing 3 among the stator core 21 and the housing 3. The electrostatic shield 5 is disposed at a distance from each of the inner peripheral surfaces 23 of the stator core 21 in the radial direction. The plurality of communication holes 50 are not blocked by the inner peripheral surface 23 of the stator core 21. In such a rotating electric machine 101, the cooling efficiency for the stator 2 is higher than when the electrostatic shield 5 is connected to the inner peripheral surface 23 of the stator core 21. In the rotating electric machine 101, since the cooling efficiency for the stator 2 is high, the stator winding 22 can also be a superconducting winding.

[0061] In the rotating electric machine 101, the electrostatic shield 5 is placed between the first wall portion 3A and the second wall portion 3B. Such an electrostatic shield 5 is disposed between the rotor 1 and the entire stator winding 22 in the radial direction, so that the stray capacitance between the rotor 1 and the stator winding 22 can be made smaller and the potential difference between the inner ring and the outer ring of each of the first bearing 4A and the second bearing 4B can be made smaller than in the rotating electric machine 102 described later.

[0062] The rotating electric machine system 201 includes a rotating electric machine 101, a supply unit 111, a recovery unit 121, and a cooling unit 131. Therefore, by configuring a circuit including the rotating electric machine 101, the supply unit 111, the recovery unit 121, and the cooling unit 131, the rotor 1 and the stator 2 of the rotating electric machine 101 can be efficiently cooled by the cooling medium circulating in the circuit. Preferably, the rotating electric machine system 201 further includes a storage unit 141. According to the rotating electric machine system 201 including the storage unit 141, the flow rate of the cooling medium circulating in the circuit can be appropriately controlled, and further high efficiency of the rotating electric machine system 201 can be realized.

[0063] <Modification> The rotor winding 12 may be a normal conducting winding. Even in this case, the electrostatic shield 5 can reduce the risk of damage to the first bearing 4A and the second bearing 4B, while suppressing the occurrence of defects associated with heat generation in the rotor winding 12 and the stator winding 22. The rotor 1 does not have to have one or both of the low temperature damper 15 and the room temperature damper 16. The outer circumferential surface 13 may be the outer circumferential surface of any member that forms the outer shell of the rotor 1 in the radial direction.

[0064] The structure of the rotor 1 for supplying the cooling medium to the rotor windings 12 is not limited to the example structure shown in FIG.

[0065] The number of each of the above-mentioned elements included in the rotating electric machine 101 and the rotating electric machine system 201 may be any number.

[0066] Embodiment 2 Unless otherwise specified, the rotating electric machine according to the embodiment 2 has the same configuration, operating principle, and effects as those of the above-mentioned embodiment 1. Therefore, the same configurations as those of the above-mentioned embodiment 1 are given the same reference numerals, and the description thereof will not be repeated.

[0067] As shown in FIG. 3, a rotating electric machine 102 according to the second embodiment includes a first electrostatic shield 5A and a second electrostatic shield 5B.

[0068] The first electrostatic shield 5A and the second electrostatic shield 5B are disposed at an interval from each other in the extending direction of the axis CA. The first electrostatic shield 5A is electrically connected to the first wall portion 3A. The second electrostatic shield 5B is electrically connected to the second wall portion 3B.

[0069] For example, one end of the first electrostatic shield 5A in the extension direction of the axis CA is electrically connected to the first wall portion 3A. The other end of the first electrostatic shield 5A in the extension direction of the axis CA is disposed at a distance from the stator core 21 in the extension direction of the axis CA.

[0070] For example, one end of the second electrostatic shield 5B in the extension direction of the axis CA is electrically connected to the second wall portion 3B. The other end of the second electrostatic shield 5B in the extension direction of the axis CA is disposed at a distance from the stator core 21 in the extension direction of the axis CA.

[0071] Each of the first electrostatic shield 5A and the second electrostatic shield 5B is disposed at a distance from the stator core 21 in the direction in which the axis CA extends. Each of the first electrostatic shield 5A and the second electrostatic shield 5B is disposed at a distance from a part of the multiple second portions 22B of the stator winding 22 in the radial direction.

[0072] From a different perspective, electrostatic shield 5 has an opening that opens into a region overlapping with stator core 21 in the radial direction. Electrostatic shield 5 is disposed so as to overlap with each part of multiple second portions 22B of stator winding 22 in the radial direction.

[0073] In the rotating electric machine 102, the electrostatic shield 5 does not overlap with the stator core 21 in the radial direction, so that the cooling medium easily flows into the multiple slots 24 of the stator core 21. As a result, the rotating electric machine 102 has a higher cooling efficiency for the stator 2 than the rotating electric machine 101.

[0074] A rotating electric machine system 202 according to the second embodiment has a similar configuration to the rotating electric machine system 201, except that it includes a rotating electric machine 102.

[0075] <Modification> The rotating electric machine 102 can be modified in the same manner as the rotating electric machine 101 .

[0076] Embodiment 3 Unless otherwise specified, the rotating electric machine according to the embodiment 3 has the same configuration, operating principle, and effects as those of the above-mentioned embodiment 1 or embodiment 2. Therefore, the same configurations as those of the above-mentioned embodiment 1 or embodiment 2 are denoted by the same reference numerals, and the description thereof will not be repeated.

[0077] As shown in FIGS. 4 and 5, a rotating electric machine 103 according to the third embodiment includes a plurality of first electrostatic shields 5A and a plurality of second electrostatic shields 5B.

[0078] Each of the multiple first electrostatic shields 5A and the multiple second electrostatic shields 5B is electrically connected to the housing 3 via the stator core 21. Each of the multiple first electrostatic shields 5A is disposed at intervals from one another in the circumferential direction. Each of the multiple second electrostatic shields 5B is disposed at intervals from one another in the circumferential direction.

[0079] Each of the plurality of first electrostatic shields 5A and the plurality of second electrostatic shields 5B has a third portion 51 disposed inside each of the plurality of slots 24. The third portion 51 of each of the plurality of first electrostatic shields 5A and the plurality of second electrostatic shields 5B is electrically connected to the stator core 21. The third portion 51 of each of the first electrostatic shields 5A and the second electrostatic shields 5B is provided so as to cover, for example, a part of the opening of the plurality of slots 24.

[0080] Each of the plurality of first electrostatic shields 5A and the plurality of second electrostatic shields 5B further has a fourth portion 52 that is disposed, for example, in the radial direction between the rotor 1 and the plurality of second portions 22B of the stator winding 22. The fourth portion 52 of each of the plurality of first electrostatic shields 5A and the plurality of second electrostatic shields 5B is disposed at a distance from the housing 3. The fourth portion 52 of each of the plurality of first electrostatic shields 5A and the plurality of second electrostatic shields 5B is disposed at a distance from the stator winding 22.

[0081] 5, the third portions 51 of each of the first electrostatic shields 5A and the second electrostatic shields 5B are disposed between each of the first portions 22A of the stator winding 22 and the pair of flanges 27 in the radial direction. Each of the third portions 51 is, for example, electrically connected to each of the pair of flanges 27. Each of the third portions 51 is in contact with, for example, each of the pair of flanges 27 and each of the tip portions of the teeth 26 connected to each of the pair of flanges 27.

[0082] In the rotating electric machine 103, similarly to the rotating electric machine 102, the electrostatic shield 5 does not overlap with the stator core 21 in the radial direction, so that the coolant easily flows between the first space S1 and the second space S2. As a result, the rotating electric machine 103 has a higher cooling efficiency for the stator 2 than the rotating electric machine 101.

[0083] Furthermore, in the rotating electric machines 101 and 102, the stator 2 and the electrostatic shield 5 must be fixed separately to the housing 3, and therefore it is necessary to manage assembly tolerances, manufacturing tolerances, and the like, for the stator 2, the housing 3, and the electrostatic shield 5. In contrast, in the rotating electric machine 103, the electrostatic shield 5 can be fixed to the housing 3 as one unit with the stator 2. Therefore, with the rotating electric machine 103, it is possible to ease the management of assembly tolerances, manufacturing tolerances, and the like, between the stator 2 and the electrostatic shield 5 and the housing 3.

[0084] A rotating electric machine system 203 according to the third embodiment has a similar configuration to the rotating electric machine system 201, except that it includes a rotating electric machine 103.

[0085] <Modification> Each of the first electrostatic shield 5A and the second electrostatic shield 5B may be fixed to an end surface of the stator core 21 in the extending direction of the axis CA.

[0086] The rotating electric machine 103 may include only one of the first electrostatic shield 5A and the second electrostatic shield 5B as the electrostatic shield. For example, when the mechanical stress applied to the second bearing 4B is larger than the mechanical stress applied to the first bearing 4A, the rotating electric machine 103 may include only the second electrostatic shield 5B as the electrostatic shield so that the electrical stress applied to the second bearing 4B is smaller than the electrical stress applied to the first bearing 4A.

[0087] The rotating electric machine 103 can be modified in the same manner as the rotating electric machines 101 and 102 . Embodiment 4 Unless otherwise specified, the rotating electric machine according to embodiment 4 has the same configuration, operating principle, and effects as any of the above-mentioned embodiments 1 to 3. Therefore, the same configurations as those in the above-mentioned embodiments 1 to 3 are given the same reference numerals, and the description thereof will not be repeated.

[0088] As shown in FIG. 6, the rotating electric machine 104 according to the fourth embodiment includes a plurality of electrostatic shields 5. Each of the plurality of electrostatic shields 5 is electrically connected to the housing 3 via the stator core 21. Each of the plurality of electrostatic shields 5 is disposed only inside each of the plurality of slots 24, for example. Each of the plurality of electrostatic shields 5 is disposed only between the rotor 1 and the plurality of first portions 22A of the stator winding 22 in the radial direction, for example. Each of the plurality of electrostatic shields 5 is not disposed between the rotor 1 and the plurality of second portions 22B of the stator winding 22 in the radial direction, for example. From a different perspective, each of the plurality of electrostatic shields 5 is composed of only the third portion 51, for example.

[0089] 7, the third portion 51 of each of the electrostatic shields 5 is disposed between each of the first portions 22A of the stator winding 22 and the pair of flanges 27 in the radial direction. Each of the third portions 51 is, for example, electrically connected to each of the pair of flanges 27. Each of the third portions 51 is in contact with, for example, each of the pair of flanges 27 and tip portions of each of the teeth 26 connected to each of the pair of flanges 27.

[0090] In the rotating electric machine 104, the electrostatic shield 5 does not overlap with the second portion 22B of the stator winding 22 in the radial direction, so that the cooling medium easily flows between the first space S1 and the second space S2. As a result, the rotating electric machine 104 has a higher cooling efficiency for the stator 2 than the rotating electric machine 101.

[0091] In the rotating electric machine 104, similarly to the rotating electric machine 103, the electrostatic shield 5 can be fixed to the housing 3 as one unit with the stator 2. Therefore, according to the rotating electric machine 104, it is possible to ease the management of assembly tolerances and manufacturing tolerances between the stator 2 and the electrostatic shield 5 and the housing 3.

[0092] The rotating electric machine system 204 according to the fourth embodiment has a similar configuration to the rotating electric machine system 201, except that it includes the rotating electric machine 104.

[0093] <Modification> Rotating electric machine 104 can be modified in the same manner as rotating electric machines 101-103.

[0094] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. At least two of the embodiments disclosed herein may be combined unless there is a contradiction. For example, a rotating electric machine 105 shown in FIG. 8 has a structure in which a rotating electric machine 101 and a rotating electric machine 104 are combined. As shown in FIG. 8, the electrostatic shields 5 may have a third portion 51 that is stretched between the first wall portion 3A and the second wall portion 3B and is disposed inside each of the slots 24.

[0095] The rotating electric machine system 205 according to the fifth embodiment has the same configuration as the rotating electric machine system 201, except that it includes the rotating electric machine 105.

[0096] The scope of the present disclosure is defined by the claims, rather than the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0097] 1 rotor, 10 shaft, 10A first shaft, 10B second shaft, 11 rotor core, 12 rotor winding, 13 outer peripheral surface, 14 slot, 15 low temperature damper, 16 room temperature damper, 2 stator, 21 stator core, 22 stator winding, 22A first portion, 22B second portion, 23 inner peripheral surface, 24 slot, 24A opening, 25 back yoke, 26 teeth, 27 flange, 3 housing, 3A first wall portion, 3B second wall portion, 3C third wall portion, 4 bearing, 4A first bearing, 4B second bearing, 5 electrostatic shield, 5A first electrostatic shield, 5B second electrostatic shield, 50 communication hole, 51 third portion, 6 magnetic shield, 101, 102, 103, 104, 105 rotating electric machine, 111 Supply section, 121 recovery section, 131 cooling section, 141 storage section, 201, 202, 203, 204 rotating electric machine system, CA axis, F1 first flow path, F2 second flow path, F3 third flow path, F4 fourth flow path, F5 fifth flow path, I1, I2 inlet, O1, O2 outlet, S1 first space, S2 second space.

Claims

1. A rotor that is rotatable about an axis; A stator; a housing that accommodates the rotor and the stator; a plurality of bearings that rotatably support the rotor relative to the housing; the rotor includes a shaft, a rotor core connected to the shaft, a rotor winding wound around the rotor core, and a room temperature damper forming an outer shell of the rotor; The stator includes a stator core connected to the housing and a stator winding. at least one electrostatic shield having a portion disposed radially relative to the axis between the warm damper of the rotor and the stator; the at least one electrostatic shield is provided with a plurality of communication holes that communicate a first space located closer to the rotor than the at least one electrostatic shield in the radial direction with a second space located on an opposite side of the rotor than the at least one electrostatic shield in the radial direction; Each of the plurality of bearings includes an inner ring electrically connected to the shaft and the room temperature damper, and an outer ring electrically connected to the housing, The at least one electrostatic shield is electrically connected to either the stator core or the housing.

2. the shaft includes a first shaft extending on one side of the rotor core in an extension direction of the axis, and a second shaft extending on the other side of the rotor core in the extension direction, the plurality of bearings include a first bearing that rotatably supports the first shaft and a second bearing that rotatably supports the second shaft, the housing has a first wall portion connected to the outer ring of the first bearing and a second wall portion connected to the outer ring of the second bearing, The rotating electric machine according to claim 1 , wherein the at least one electrostatic shield is electrically connected to at least one of the first wall portion and the second wall portion.

3. The rotating electric machine according to claim 2 , wherein the at least one electrostatic shield spans between the first wall portion and the second wall portion.

4. the at least one electrostatic shield is a plurality of electrostatic shields including a first electrostatic shield and a second electrostatic shield; the first electrostatic shield and the second electrostatic shield are disposed at an interval from each other in an extension direction of the axis, the first electrostatic shield is electrically connected to the first wall portion; The rotating electric machine according to claim 2 , wherein the second electrostatic shield is electrically connected to the second wall portion.

5. 5. The rotating electric machine according to claim 2, wherein the at least one electrostatic shield is disposed at a distance from the stator.

6. The rotating electric machine according to claim 1 , wherein the at least one electrostatic shield is electrically connected to the housing through the stator core.

7. the shaft includes a first shaft extending on one side of the rotor winding in an extension direction of the axis, and a second shaft extending on the other side of the rotor winding in the extension direction, the plurality of bearings include a first bearing that rotatably supports the first shaft and a second bearing that rotatably supports the second shaft, the housing has a first wall portion connected to the outer ring of the first bearing and a second wall portion connected to the outer ring of the second bearing, the at least one electrostatic shield is a plurality of electrostatic shields including a first electrostatic shield and a second electrostatic shield; the first electrostatic shield and the second electrostatic shield are disposed at an interval from each other in an extension direction of the axis, the first electrostatic shield is electrically connected to one end of the stator core in an extending direction of the axis, The rotating electric machine according to claim 6 , wherein the second electrostatic shield is electrically connected to the other end of the stator core in the direction in which the axis extends.

8. the stator core has an inner circumferential surface surrounding the rotor winding in the radial direction, The stator core is provided with at least one slot that opens to the inner circumferential surface, a portion of the stator winding disposed within the at least one slot; The rotating electric machine according to any one of claims 1 to 4, wherein the at least one electrostatic shield has a portion that is disposed within the at least one slot so as to block the opening of the at least one slot.

9. The rotating electric machine according to claim 8 , wherein the at least one electrostatic shield comprises only a portion disposed within the at least one slot.

10. the stator core has a cylindrical back yoke, a plurality of teeth protruding from the back yoke toward the rotor, and a plurality of flanges protruding from inner peripheral ends of the plurality of teeth in the radial direction in a circumferential direction relative to the shaft, The at least one slot is formed between the teeth, the opening of the at least one slot is formed between the flanges of each of the plurality of teeth; The rotating electric machine according to claim 8 , wherein the at least one electrostatic shield is disposed between the portion of the stator winding and the flange in the radial direction.

11. The rotating electric machine according to claim 6 or 7, wherein the at least one electrostatic shield is disposed at a distance from the housing.

12. the housing is a container that contains a cooling medium for cooling the rotor winding, the rotor is provided with a first flow passage through which the cooling medium flows from the outside of the housing through the rotor winding into the first space, 5. The rotating electric machine according to claim 1, wherein the housing is provided with a second flow passage through which the cooling medium flows from the second space to an outside of the housing.

13. The rotating electric machine according to claim 12 , wherein the rotor winding is a superconducting winding.

14. A rotating electric machine according to claim 12; a supply unit for supplying the cooling medium to the first flow path; a recovery unit for recovering the cooling medium from the second flow path.

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