synchronous machine

Abstract

To obtain a synchronous machine capable of improving cooling performance. [Solution] The rotor core includes a rotor core, a laminated coil, and an insulator. The rotor core has an outer peripheral surface extending circumferentially around a rotation axis, and is provided with slots recessed radially from the outer peripheral surface perpendicular to the rotation axis, and sub-slots communicating with ends of the slots on the inside in the radial direction, and is configured to rotate around the rotation axis. The laminated coil has multiple coils stacked in the radial direction and is disposed in the slot. The insulator is disposed in the slot, is located between the sub-slot and the laminated coil, and is provided with a recess communicating with the sub-slot.

Description

[Technical Field]

[0001] The present invention relates to a synchronous machine. [Background technology]

[0002] Conventionally, a synchronous machine such as a synchronous generator or a synchronous motor includes a rotor core and coils. Axially extending slits are provided on the outer circumferential surface of the rotor core. Coils are stacked in the slits. Axially extending sub-slots are provided at the bottom of the slits. Airflow flows into the sub-slots to cool the rotor core and coils. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-142398 Summary of the Invention [Problem to be solved by the invention]

[0004] If the sub-slot is enlarged, the airflow flowing into the sub-slot increases, improving the cooling performance of the synchronous machine. However, the size of the sub-slot may be limited, for example, due to the strength of the rotor core.

[0005] One example of a problem to be solved by the present invention is to provide a synchronous machine capable of improving cooling performance. [Means for solving the problem]

[0006] A synchronous machine according to an embodiment of the present invention includes a rotor core, a laminated coil, and an insulator. The rotor core has an outer peripheral surface extending in a circumferential direction about a rotation axis, and is provided with slots recessed from the outer peripheral surface in a radial direction perpendicular to the rotation axis and sub-slots communicating with ends of the slots on the inside in the radial direction, and is configured to rotate about the rotation axis. The laminated coil has multiple coils stacked in the radial direction and is disposed in the slot. The insulator is disposed in the slot, is located between the sub-slot and the laminated coil, and is provided with a recess communicating with the sub-slot. [Effects of the Invention]

[0007] According to the synchronous machine of the present invention, for example, the cooling performance can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a synchronous generator according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a part of the rotor of the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing a part of the rotor of the first embodiment taken along line F3-F3 in FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a part of the rotor in the vicinity of one slot of the first embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing a part of a rotor in the vicinity of one slot according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment) The first embodiment will be described below with reference to FIGS. 1 to 4. In this specification, components according to the embodiment and descriptions of the components may be described using multiple expressions. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may also be identified by names different from those in this specification. Furthermore, the components may also be described using expressions different from those in this specification.

[0010] In the following description, "inhibit" is defined as, for example, preventing an event, action, or effect from occurring or reducing the magnitude of an event, action, or effect.

[0011] FIG. 1 is a cross-sectional view schematically illustrating a synchronous generator 10 according to a first embodiment. The synchronous generator 10 is an example of a synchronous machine, and may also be referred to as a rotating electric machine. The synchronous machine may also be a synchronous motor. As shown in FIG. 1, the synchronous generator 10 includes a housing 11, a rotor 12, a stator 13, two fans 14, and a cooler 15.

[0012] The housing 11 houses a part of the rotor 12, a stator 13, two fans 14, and a cooler 15. Furthermore, the inside of the housing 11 is filled with a cooling gas, which may be air or another gas.

[0013] Fig. 2 is a cross-sectional view showing a portion of the rotor 12 of the first embodiment. As shown in Fig. 2, the rotor 12 has a shaft 21, a rotor core 22, and a plurality of laminated coils 23. The rotor 12 can rotate around a central axis Ax. The central axis Ax is the center of rotation of the rotor 12, and is, for example, the center line of the shaft 21. The central axis Ax is an example of a rotation axis.

[0014] In the following description, the axial direction, radial direction, and circumferential direction are defined. The axial direction is the direction along the central axis Ax. The radial direction is the direction perpendicular to the central axis Ax. The circumferential direction is the direction around the central axis Ax.

[0015] The shaft 21 is formed in a substantially cylindrical shape extending along the central axis Ax. The shaft 21 is supported by the housing 11 via, for example, a bearing so as to be rotatable about the central axis Ax. As shown in Fig. 1, a portion of the shaft 21 is located outside the housing 11 and is connected to, for example, another device.

[0016] The rotor core 22 is located inside the housing 11 and is formed in a generally cylindrical shape extending along the central axis Ax. In this embodiment, the rotor core 22 is formed integrally with the shaft 21. That is, the rotor core 22 is a part of the shaft 21. Therefore, the rotor core 22 can rotate around the central axis Ax integrally with the shaft 21. However, the rotor core 22 is not limited to this example.

[0017] 2, the plurality of laminated coils 23 are arranged in the circumferential direction and attached to the rotor core 22. Therefore, the plurality of laminated coils 23 can rotate integrally with the shaft 21 and the rotor core 22 around the central axis Ax.

[0018] As shown in Fig. 1, the stator 13 has a stator core 31 and a stator winding 32. The stator core 31 is formed in a substantially cylindrical shape extending in the circumferential direction, and is fixed to the housing 11. The rotor core 22 is disposed inside the stator core 31. A gap is provided between the rotor core 22 and the stator core 31. The stator winding 32 is attached to the stator core 31.

[0019] When the laminated coil 23 is excited and the rotor 12 rotates around the central axis Ax relative to the stator 13, a current is generated in the stator winding 32. This allows the synchronous generator 10 to obtain electric power.

[0020] The two fans 14 are attached to a shaft 21. The rotor core 22 is disposed between the two fans 14. The fans 14 rotate integrally with the rotor 12 around the central axis Ax. As the fans 14 rotate, they cause a cooling gas C to flow axially toward the rotor core 22.

[0021] 1, the cooling gas C passes through the rotor 12 and the stator 13 and is introduced into the cooler 15. The cooler 15 cools the cooling gas C. The cooling gas C passes from the cooler 15 through a flow path in the housing 11 and is introduced again into the fan 14. In this way, the cooling gas C circulates inside the housing 11.

[0022] When the cooling gas C passes through the rotor 12, it comes into direct contact with the rotor core 22 and the laminated coils 23. That is, the synchronous generator 10 of this embodiment cools the rotor 12 by a so-called direct cooling method.

[0023] Fig. 3 is a cross-sectional view showing a part of the rotor 12 of the first embodiment taken along line F3-F3 in Fig. 2. The rotor core 22 further has an outer peripheral surface 41 shown in Fig. 2 and two end surfaces 42 shown in Fig. 3.

[0024] 2, the outer peripheral surface 41 is a substantially cylindrical curved surface extending in the circumferential direction. The outer peripheral surface 41 faces the stator core 31 via a gap. The diameter of the outer peripheral surface 41 of the rotor core 22 is larger than the diameter of the shaft 21. Therefore, the rotor core 22 protrudes radially outward from the shaft 21.

[0025] 3, two end faces 42 are provided on both axial ends of the rotor core 22. The end faces 42 are formed to be approximately flat and face the axial direction. However, the end faces 42 are not limited to this example.

[0026] As shown in Fig. 2, the rotor core 22 is provided with a plurality of slots 45 and a plurality of sub-slots 46. The slots 45 may also be referred to as coil slots. The number of sub-slots 46 is equal to the number of slots 45. However, the number of sub-slots 46 may be less than the number of slots 45.

[0027] 4 is a cross-sectional view showing a portion of the rotor 12 in the vicinity of one slot 45 of the first embodiment. As shown in FIG. 4, the slot 45 is recessed radially inward from the outer circumferential surface 41. The laminated coil 23 is disposed in the slot 45.

[0028] The rotor core 22 further has a bottom surface 45a and two side surfaces 45b. The bottom surface 45a and the two side surfaces 45b define a slot 45. The bottom surface 45a is provided at an end of the slot 45 on the inside in the radial direction. The two side surfaces 45b extend in a substantially radial direction between both ends of the bottom surface 45a in the circumferential direction and the outer circumferential surface 41. The two side surfaces 45b face each other.

[0029] The sub-slots 46 are recessed radially inward from the bottom surface 45a. That is, the sub-slots 46 communicate with the radially inner ends of the slots 45. The width of the sub-slots 46 in the circumferential direction is smaller than the width of the slots 45.

[0030] As shown in Fig. 2, the multiple slots 45 are aligned in the circumferential direction with gaps between them. Therefore, the multiple sub-slots 46 are also aligned in the circumferential direction with gaps between them. As shown in Fig. 3, the slots 45 and the sub-slots 46 each penetrate the rotor core 22 in a substantially axial direction and open to the two end faces 42. Note that the slots 45 and the sub-slots 46 may extend obliquely with respect to the axial direction.

[0031] 4, the rotor 12 has two insulating sheets 51, an insulating plate 52, a wedge 53, and a creepage block 54 in each of the multiple slots 45. That is, the insulating sheet 51, the insulating plate 52, the wedge 53, and the creepage block 54 are arranged in the slot 45. The insulating plate 52 is an example of an insulator.

[0032] The insulating sheet 51 and the insulating plate 52 are insulators and are made of, for example, epoxy glass cloth. Note that the insulating sheet 51 and the insulating plate 52 may be made of other materials or may be made of different materials.

[0033] Each insulating sheet 51 covers the bottom surface 45a and one of the side surfaces 45b. As a result, the insulating sheet 51 is interposed between the laminated coil 23 and the side surface 45b, providing insulation between the rotor core 22 and the laminated coil 23. The two insulating sheets 51 are spaced apart from each other in the circumferential direction. The laminated coil 23 is located between the two insulating sheets 51.

[0034] The insulating plate 52 is thicker and more rigid than the insulating sheet 51. For example, the thickness of the insulating plate 52 is about three times the thickness of the insulating sheet 51. However, the insulating plate 52 is not limited to this example.

[0035] The insulating plate 52 is located between the laminated coil 23 and the bottom surface 45a of the rotor core 22. That is, the insulating plate 52 is located between the laminated coil 23 and the sub-slot 46. The insulating plate 52 has an inner surface 52a and an outer surface 52b shown in FIG. 4, and two end surfaces 52c shown in FIG. 3.

[0036] As shown in Fig. 4, the inner surface 52a faces radially inward. The inner surface 52a faces the bottom surface 45a of the rotor core 22. The insulating sheet 51 is interposed between the inner surface 52a of the insulating plate 52 and the bottom surface 45a of the rotor core 22. The inner surface 52a of the insulating plate 52 is supported by the bottom surface 45a of the rotor core 22 via the insulating sheet 51. Note that the insulating plate 52 may be in contact with the bottom surface 45a.

[0037] The outer surface 52b is located on the opposite side to the inner surface 52a. The outer surface 52b faces radially outward. The outer surface 52b faces the laminated coil 23. The laminated coil 23 is spaced radially outward from the outer surface 52b, taking into account, for example, centrifugal force. Therefore, a gap G is provided between the outer surface 52b and the laminated coil 23. The outer surface 52b may be in contact with the laminated coil 23.

[0038] 3, the two end faces 52c are provided on both ends of the insulating plate 52 in the axial direction. In the axial direction, the end face 52c of the insulating plate 52 is disposed at approximately the same position as the end face 42 of the rotor core 22. However, the position of the end face 52c is not limited to this example.

[0039] 4, insulating plate 52 is provided with a groove 61 and a plurality of ventilation holes 62. Groove 61 is an example of a recess. Ventilation holes 62 are an example of a second through hole, and may also be called a radial path.

[0040] The groove 61 is recessed radially outward from the inner surface 52a. The radial depth of the groove 61 is one-third to two-thirds of the thickness of the insulating plate 52. However, the depth of the groove 61 is not limited to this example.

[0041] The groove 61 communicates with the sub-slot 46. For example, the groove 61 communicates with the sub-slot 46 through the space between two insulating sheets 51 that are spaced apart from each other. The width of the groove 61 in the circumferential direction is equal to or greater than the width of the sub-slot 46. In this embodiment, the width of the groove 61 and the width of the sub-slot 46 are approximately equal. However, the width of the groove 61 is not limited to this example, and may be smaller than the width of the sub-slot 46.

[0042] 3, the groove 61 is provided between the two end faces 52c and opens to both end faces 52c. That is, the groove 61 opens to both ends of the insulating plate 52 in the axial direction. Note that the groove 61 may open to one end face 52c, may be spaced apart from the two end faces 52c, or may be divided in the axial direction.

[0043] The depth and width of the groove 61 are substantially constant. Therefore, the groove 61 can be easily formed by, for example, cutting. However, the depth and width of the groove 61 may vary. Furthermore, the groove 61 may be formed by other methods.

[0044] 4, in the first embodiment, the cross section of the groove 61 perpendicular to the central axis Ax is formed to be substantially rectangular. The insulating plate 52 further has a bottom surface 61a, two side surfaces 61b, and two curved surfaces 61c. The bottom surface 61a, the two side surfaces 61b, and the two curved surfaces 61c define the groove 61.

[0045] The bottom surface 61a and the two side surfaces 61b are each formed to be approximately flat. The bottom surface 61a is provided at the end of the groove 61 on the radially outer side and faces radially inward. The radial depth of the groove 61 is the distance between the bottom surface 61a and the inner surface 52a.

[0046] The two side surfaces 61b extend substantially radially between the inner surface 52a and both ends of the bottom surface 61a in the circumferential direction. The two side surfaces 61b face each other. The width of the groove 61 in the circumferential direction is the distance between the two side surfaces 61b.

[0047] Each curved surface 61c is located between an end of the bottom surface 61a and the side surface 61b in the circumferential direction. The curved surface 61c is a substantially semi-cylindrical curved surface. That is, the corners between the bottom surface 61a and the side surface 61b are rounded and chamfered, thereby suppressing stress concentration. However, the corners between the bottom surface 61a and the side surface 61b are not limited to this example.

[0048] Each of the plurality of ventilation holes 62 penetrates the insulating plate 52 in a substantially radial direction. The ventilation holes 62 open to the outer surface 52b and the bottom surface 61a. In the circumferential direction, the width of the ventilation holes 62 is smaller than the width of the grooves 61. However, the ventilation holes 62 are not limited to this example. As shown in FIG. 3, the plurality of ventilation holes 62 are arranged in the axial direction at intervals.

[0049] As shown in Fig. 4, the wedges 53 are located at the radially outer ends of the slots 45. The wedges 53 are fixed to the rotor core 22 and close the slots 45 in the radial direction. The creepage blocks 54 are interposed between the laminated coils 23 and the wedges 53. The wedges 53 hold the laminated coils 23 in the radial direction via the creepage blocks 54.

[0050] A ventilation hole 71 is provided in the wedge 53. The ventilation hole 71 passes radially through the wedge 53. Furthermore, a ventilation hole 75 is also provided in the creepage block 54. The ventilation hole 75 passes radially through the creepage block 54 and communicates with the ventilation hole 71.

[0051] The laminated coil 23 includes a plurality of coils 81 and a plurality of insulating sheets 82. The coils 81 may also be referred to as field conductors, windings, or conductor bars. The insulating sheets 82 may also be referred to as turn insulators.

[0052] The coil 81 is made of a conductor such as copper and extends substantially in the axial direction. The coil 81 may extend obliquely relative to the axial direction. The multiple coils 81 are stacked in the radial direction. That is, the multiple coils 81 are lined up in the radial direction and supported by one another.

[0053] The insulating sheet 82 is an insulator and is made of, for example, epoxy glass cloth. However, the insulating sheet 82 may be made of other materials. The insulating sheet 82 is thinner than the insulating sheet 51. For example, the thickness of the insulating sheet 82 is about one-fourth of the thickness of the insulating sheet 51. However, the thickness of the insulating sheet 82 is not limited to this example. Each insulating sheet 82 is interposed between two adjacent coils 81. In this way, the insulating sheet 82 insulates the two coils 81.

[0054] The laminated coil 23 has an inner surface 23a and an outer surface 23b. The inner surface 23a is provided at an end of the laminated coil 23 on the inner side in the radial direction. The outer surface 23b is provided at an end of the laminated coil 23 on the outer side in the radial direction. The inner surface 23a and the outer surface 23b may be formed by the coil 81 or by the insulating sheet 82.

[0055] The inner surface 23a faces inward in the radial direction. For example, the inner surface 23a faces the outer surface 52b of the insulating plate 52 with a gap G therebetween. The outer surface 23b faces outward in the radial direction. For example, the outer surface 23b abuts against the creepage block 54.

[0056] 3, a plurality of ventilation holes 85 are provided in the laminated coil 23. The ventilation holes 85 are an example of first through holes. The ventilation holes 85 are arranged, for example, in two rows in the axial direction. However, the arrangement of the ventilation holes 85 is not limited to this example.

[0057] The ventilation holes 85 penetrate the laminated coil 23 in a substantially radial direction and open to the inner surface 23a and the outer surface 23b. That is, the ventilation holes 85 open to both ends of the laminated coil 23 in the radial direction. The ventilation holes 85 include through holes provided in the coil 81 and through holes provided in the insulating sheet 82.

[0058] 4, the ventilation holes 85 communicate with the ventilation holes 62 of the insulating plate 52 through, for example, the gap G. Therefore, the ventilation holes 62 communicate with the grooves 61 and the ventilation holes 85 of the laminated coil 23. The ventilation holes 75 of the creepage block 54 communicate with the ventilation holes 85 of the laminated coil 23 and the ventilation holes 71 of the wedge 53.

[0059] 3, the laminated coils 23, the wedges 53, and the creepage blocks 54 are axially longer than the rotor core 22. Therefore, portions of the laminated coils 23, the wedges 53, and the creepage blocks 54 protrude from the two end faces 42 of the rotor core 22.

[0060] The rotor 12 has two retaining rings 91. The retaining rings 91 are formed, for example, in the shape of an annular ring extending in the circumferential direction. The retaining rings 91 hold the multiple laminated coils 23 from the radial outside at a position axially spaced from the rotor core 22.

[0061] 4, the sub-slot 46 and the groove 61 that are in communication with each other form one flow path 100. The flow path 100 is the sub-slot 46 that is expanded radially outward by the groove 61. Note that the flow path 100 may include other spaces, such as the spaces between the insulating sheets 51 that are spaced apart from each other.

[0062] The shape of the sub-slots 46 is set based on, for example, the strength of the rotor core 22 and the amount of heat dissipation from the rotor 12. For this reason, it is difficult to enlarge the sub-slots 46 themselves. However, the grooves 61 can substantially increase the cross-sectional area of ​​the flow passages 100 without enlarging the sub-slots 46 themselves.

[0063] During power generation by the synchronous generator 10, heat is generated due to, for example, electrical loss in the coil 81. This heat generation causes the temperature of the coil 81 to rise. The synchronous generator 10 cools the coil 81 to suppress an increase in the electrical resistance of the coil 81 that accompanies a temperature rise.

[0064] For example, as described above, when the rotor 12 rotates around the central axis Ax, the fan 14 generates an axial airflow of the cooling gas C. This airflow flows into the flow path 100. Furthermore, due to the centrifugal fan effect caused by the rotation of the rotor 12, the cooling gas C flows into the flow path 100. The cross-sectional area of ​​the flow path 100 is larger than the cross-sectional area of ​​the sub-slot 46. Therefore, a larger amount of the cooling gas C flows into the flow path 100.

[0065] The cooling gas C flows from the flow path 100 into the plurality of ventilation holes 62. The cooling gas C flows through the ventilation holes 62, 85, 75, and 71 and comes into direct contact with the plurality of coils 81. As a result, the cooling gas C cools the plurality of coils 81.

[0066] Since the cross-sectional area of ​​the flow path 100 is large, the flow rate of the cooling gas C flowing from the flow path 100 into the ventilation holes 85 also increases. Therefore, the synchronous generator 10 can cool the coil 81 more effectively.

[0067] Furthermore, the temperature of rotor core 22 rises due to heat conduction from, for example, coil 81. When cooling gas C flows through flow path 100, it comes into direct contact with rotor core 22. As a result, cooling gas C can cool rotor core 22 and indirectly cool coil 81.

[0068] In the synchronous generator 10 according to the first embodiment described above, the rotor core 22 has an outer peripheral surface 41. The outer peripheral surface 41 extends in the circumferential direction about the central axis Ax. The rotor core 22 is provided with slots 45 and sub-slots 46. The slots 45 are recessed from the outer peripheral surface 41 in a radial direction perpendicular to the central axis Ax. The sub-slots 46 communicate with ends of the slots 45 on the inside in the radial direction. The rotor core 22 is configured to rotate about the central axis Ax. The laminated coil 23 has a plurality of coils 81 laminated in the radial direction and is disposed in the slots 45. The insulating plate 52 is disposed in the slot 45 and is located between the sub-slots 46 and the laminated coil 23. The insulating plate 52 is provided with grooves 61 that communicate with the sub-slots 46.

[0069] When the rotor core 22 rotates, a current of cooling gas C is generated by, for example, the fan 14 that rotates integrally with the rotor core 22. The cooling gas C cools the rotor core 22 by flowing through the sub-slots 46. Because the grooves 61 of the insulating plate 52 communicate with the sub-slots 46, the synchronous generator 10 can expand the flow paths 100 through which the cooling gas C can pass without expanding the sub-slots 46 themselves. This allows the synchronous generator 10 to improve cooling performance and suppress a decrease in the strength of the rotor core 22 that would be caused by the expansion of the sub-slots 46.

[0070] The laminated coil 23 is provided with ventilation holes 85 that open at both ends of the laminated coil 23 in the radial direction. The insulating plate 52 is provided with ventilation holes 62 that communicate with the grooves 61 and the ventilation holes 85. As a result, the cooling gas C flows from the sub-slots 46 through the ventilation holes 62 into the ventilation holes 85 due to the centrifugal fan effect. The cooling gas C cools the laminated coil 23 by flowing through the ventilation holes 85. The grooves 61 enlarge the flow paths 100 through which the cooling gas C can pass, thereby increasing the flow rate of the cooling gas C flowing into the ventilation holes 62 and 85. Therefore, the synchronous generator 10 can improve its cooling performance.

[0071] In the circumferential direction, the width of the groove 61 is equal to or greater than the width of the sub-slot 46. This allows the synchronous generator 10 to further expand the flow path 100 through which the cooling gas C can pass, thereby improving cooling performance. If the groove 61 were large, the rigidity of the insulating plate 52 would be reduced. However, the insulating plate 52 is located between the bottom surface 45a of the slot 45 and the laminated coil 23. Therefore, even if centrifugal force acts on the laminated coil 23 when the rotor core 22 rotates, almost no load is applied from the laminated coil 23 to the insulating plate 52. Therefore, even if the width of the groove 61 is set large, damage to the insulating plate 52 can be suppressed.

[0072] In the radial direction, the depth of the grooves 61 is one-third to two-thirds the thickness of the insulating plate 52. This allows the synchronous generator 10 to have a larger flow path 100 through which the cooling gas C can pass, compared to when the grooves 61 are smaller in depth. If the grooves 61 are larger, the rigidity of the insulating plate 52 may decrease. However, the insulating plate 52 is located between the bottom surfaces 45a of the slots 45 and the laminated coils 23. Therefore, even if centrifugal force acts on the laminated coils 23 when the rotor core 22 rotates, almost no load acts on the insulating plate 52 from the laminated coils 23. Therefore, even if the depth of the grooves 61 is set large, damage to the insulating plate 52 can be suppressed.

[0073] The grooves 61 open to both ends of the insulating plate 52 in the axial direction along the central axis Ax. That is, the grooves 61 extend from one end of the insulating plate 52 to the other in the axial direction. This allows the cooling gas C to flow smoothly through the flow passage 100 enlarged by the grooves 61.

[0074] (Second embodiment) The second embodiment will be described below with reference to Fig. 5. In the following description of the embodiment, components having the same functions as components already described are given the same reference numerals as the components already described, and further description may be omitted. Furthermore, multiple components given the same reference numerals do not necessarily have all the same functions and properties, and may have different functions and properties according to each embodiment.

[0075] Fig. 5 is a cross-sectional view showing a portion of the rotor 12 in the vicinity of one slot 45 according to the second embodiment. As shown in Fig. 5, the insulating plate 52 of the second embodiment is provided with a groove 201 instead of the groove 61. The groove 201 is substantially the same as the groove 61, except for the points described below.

[0076] In a cross section of the insulating plate 52 perpendicular to the central axis Ax, the groove 201 is recessed in an arc shape from the inner surface 52a of the insulating plate 52. In other words, the groove 201 is recessed in an arc shape from the end of the insulating plate 52 on the inside in the radial direction.

[0077] For example, during assembly of the synchronous generator 10, the laminated coil 23 may be temporarily placed on the outer surface 52b of the insulating plate 52. The insulating plate 52 of the second embodiment has an arch-shaped structure, and is therefore able to support a heavier laminated coil 23 than other structures. Furthermore, since the grooves 201 are arc-shaped, the insulating plate 52 can suppress stress concentration.

[0078] In the synchronous generator 10 of the second embodiment described above, the groove 201 is recessed in an arc shape from the radially inner end of the insulating plate 52. Therefore, the insulating plate 52 can suppress stress concentration.

[0079] The above-described embodiments of the present invention do not limit the scope of the invention, but are merely examples within the scope of the invention. Some embodiments of the present invention may be modified, omitted, or added to the above-described embodiments, for example, with respect to at least part of the specific applications, structures, shapes, actions, and effects, without departing from the spirit of the invention. [Explanation of symbols]

[0080] 10...synchronous generator (synchronous machine), 22...rotor core, 23...laminated coil, 41...outer surface, 45...slot, 46...sub-slot, 52...insulating plate (insulator), 61, 201...groove (recess), 62...ventilation hole (second through hole), 81...coil, 85...ventilation hole (first through hole), Ax...central axis (rotating axis).

Claims

1. a rotor core having an outer peripheral surface extending in a circumferential direction around a rotation axis, and provided with slots recessed from the outer peripheral surface in a radial direction perpendicular to the rotation axis, and sub-slots communicating with ends of the slots on the inner side in the radial direction, and configured to rotate around the rotation axis; a laminated coil having a plurality of coils laminated in the radial direction and disposed in the slot; an insulator disposed in the slot, the insulator being positioned between the sub-slot and the laminated coil and having a recess communicating with the sub-slot; A synchronous machine comprising:

2. the laminated coil is provided with first through holes that open to both ends of the laminated coil in the radial direction, a second through hole communicating with the recess and the first through hole is provided in the insulator; The synchronous machine of claim 1.

3. In the circumferential direction, the width of the recess is equal to or greater than the width of the sub-slot. The synchronous machine according to claim 1 or 2.

4. a depth of the recess in the radial direction is one-third to two-thirds of a thickness of the insulator; The synchronous machine according to claim 1 or 2.

5. the recessed portion is open to both ends of the insulator in the axial direction along the rotation shaft. The synchronous machine according to claim 1 or 2.

Images