JP2023089647A - Rotor of rotary electric machine - Google Patents

Abstract

To reduce the draft loss of a rotary electric machine while efficiently cooling a rotor coil.SOLUTION: According to an embodiment, a rotor of a rotary electric machine is provided, comprising: a rotor shaft; a rotor spoke which is provided to the circumferential outside of the rotor shaft; a rotor rim which is provided to the circumferential outside of the rotor spoke and has a rim duct that constitutes a cooling gas passage; a plurality of poles which are provided to the circumferential outside of the rotor rim and arranged by being spaced apart in the circumferential direction; and a rotor coil which is provided to each of the plurality of poles. The rotor of the rotary electric machine further includes a ventilation guide that guides a cooling gas that flows out from the rim duct to between the poles, in such a way that the cooling gas branches off in the rotor circumferential direction between the poles and flows radially outward along the respective wall surfaces of the poles on both sides.SELECTED DRAWING: Figure 1

Description

An embodiment of the present invention relates to a rotor of a rotating electric machine.

In general, a rotating electric machine such as a water turbine generator has a ventilation cooling structure in which a cooling gas circulates inside the machine. There are two types of water turbine generators: constant speed and variable speed, each of which has a different structure. In the following, the structure of a constant speed machine will be described as an example.

A water turbine generator is composed of a generator and a water turbine, and the generator has a rotor and a stator. Specific examples of the configuration of this generator are shown in FIGS. 11 to 13. FIG. FIG. 11 is a vertical cross-sectional view showing the configuration of a rotor of a general rotary electric machine. 12 is a longitudinal sectional view showing the structure of part of the rotating electrical machine, and FIG. 13 is a radial sectional view showing the structure of part of the rotor of the rotating electrical machine. Reference character F in each figure indicates the flow of the cooling gas.

The generator 100 includes an upper bearing 51a, a lower bearing 51b, a collector 52, an airway cover 53, etc. Inside the airway cover 53, a rotor 61 and a stator 62 are arranged.

The rotor 61 includes a rotor shaft (shaft) 1 having an upper shaft 1a and a lower shaft 1b between an upper bearing 51a and a lower bearing 51b. A child rim 7 is attached. A plurality of salient poles (magnetic poles) 9 are arranged at equal intervals in the circumferential direction on the outer diameter side of the rotor rim 7 . Each pole 9 is composed of a magnetic pole core and a rotor coil (field coil) 10 . A plurality of rim ducts 8 are arranged in the axial direction and the circumferential direction of the rotor rim 7 so as to communicate radially from the inside of the rotor spokes 3 to the poles 9 .

On the other hand, the stator 62 includes a stator core 32, a stator coil 33, a connection copper band 34, etc. housed in the stator frame 31. As shown in FIG. A cooler (gas cooler) 35 is also attached to the outside of the stator frame 31 .

In the generator 100 having such a configuration, since the rotor coil 10, the pole 9 having the magnetic pole core around which the rotor coil is wound, the stator core 32, the stator coil 33, etc. generate heat, a cooling gas is supplied to the inside of the machine. Circulate and cool. This cooling gas circulation generally utilizes the centrifugal fan effect of the rotation of the rotor 61 .

Due to the centrifugal fan effect of the rotor 61, the cooling gas is taken into the interior of the rotor spokes 3 from the inflow holes 4 provided in the rotor spokes 3, and passes through the rim ducts 8 provided in the rotor rim 7 to the individual Pass between poles 9. The cooling gas heated to a high temperature by cooling the poles 9 is discharged to the air gap G between the rotor 61 and the stator 62 .

Part of the high-temperature cooling gas discharged into the air gap G flows out from the air gap G in the axial direction of the rotor, and the remaining cooling gas passes through the stator duct 17 provided in the stator core 32, It flows out to the core back surface 36 on the outer diameter side of the stator core 32 and exchanges heat with the cooling water or the like of the cooler 35 attached to the outer diameter side of the stator frame 31 . The cooling gas, whose temperature has been lowered by heat exchange with the cooler 35, is sent from the outside of the stator frame 31 to the rotor 61 side, and again enters the rotor spokes 3 through the inflow holes 4 provided in the rotor spokes 3. It will be taken in and circulated.

Regarding the cooling technology of the rotor of the rotating electric machine, for the purpose of improving the efficiency, technological development of the structure and configuration for more effective cooling using less cooling gas is underway. For example, a technique has been proposed to rectify the flow of cooling gas in rotor spokes of a rotor to reduce ventilation loss.

JP-A-59-117439

In the configuration described above, in the space between individual poles through which the cooling gas passes in the circulation path of the cooling gas, the cooling gas flows in a complicated manner, generating vortices and the like. This causes ventilation loss and lowers generator efficiency. Also, in the vicinity of the coil wound on the pole where cooling is most required, the flow velocity is slow and the cooling effect is low.

The problem to be solved by the present invention is to provide a rotor for a rotating electric machine that can efficiently cool the rotor coils while reducing the ventilation loss of the rotating electric machine.

According to the embodiment, a rotor shaft, rotor spokes provided on the outer peripheral side of the rotor shaft, a rotor rim having a rim duct provided on the outer peripheral side of the rotor spokes and serving as a passage for cooling gas, A rotor for a rotating electric machine, comprising: a plurality of poles provided on the outer peripheral side of the rotor rim and arranged at intervals in the circumferential direction; and rotor coils provided respectively on the plurality of poles, wherein the rim duct The cooling gas flowing out between the poles from the rotor branches in the circumferential direction of the rotor between the poles and flows along the wall surfaces of the poles on both sides to the outer diameter side. An electric machine rotor is provided.

ADVANTAGE OF THE INVENTION According to this invention, a rotor coil can be efficiently cooled, reducing the ventilation loss of a rotary electric machine.

FIG. 2 is a radial cross-sectional view showing the structure of part of the rotor of the rotary electric machine according to the first embodiment; The side view which looked at the rotor of the rotary electric machine which concerns on the same embodiment from the rotor outer diameter side. FIG. 3 is a perspective view showing the shape of the ventilation guide shown in FIGS. 1 and 2; FIG. 2 is a radial cross-sectional view showing a first modification to the structure shown in FIG. 1; FIG. 2 is a radial cross-sectional view showing a second modification to the structure shown in FIG. 1; FIG. 6 is a radial cross-sectional view showing the structure of a portion of the rotor of the rotating electric machine according to the second embodiment; FIG. 7 is a perspective view showing the shape of the ventilation guide shown in FIG. 6; FIG. 8 is a radial cross-sectional view showing a modification to the structure shown in FIG. 7; The perspective view which shows the shape of the ventilation guide by 3rd Embodiment. FIG. 10 is a side view of the rotor including the ventilation guide shown in FIG. 9 as viewed from the outer diameter side of the rotor; FIG. 2 is a vertical cross-sectional view showing the configuration of a rotor of a general rotary electric machine; FIG. 2 is a longitudinal sectional view showing the structure of part of a common rotating electric machine; FIG. 2 is a radial cross-sectional view showing the structure of part of a rotor of a general rotary electric machine;

Embodiments will be described below with reference to the drawings.

[First embodiment]
First, the first embodiment will be described with reference to FIGS. 1 to 5 and appropriately to FIGS. 11 and 12 described above. Elements common to those in FIGS. 11 and 12 described above are denoted by the same reference numerals, and overlapping descriptions are omitted.

FIG. 1 is a radial cross-sectional view showing a partial structure of a rotor of a rotating electric machine according to a first embodiment, and FIG. is a side view. 3 is a perspective view showing the shape of the ventilation guide shown in FIGS. 1 and 2. FIG.

The rotor of the rotary electric machine according to the first embodiment has a basic structure similar to that shown in FIGS. 1 to 3, it has a structure in which the ventilation guide 14 is fixed to the rotor rim 7 by, for example, a ventilation guide support 15. As shown in FIG.

As can be understood from FIGS. 11 and 12, the rotor spoke mechanism 2 is fixed to the rotor shaft 1, and the rotor spoke mechanism 2 radially rotates around the rotor shaft 1. It consists of rotor spokes 3 extending outward from one surface and end plates 5 fixed to the upper and lower ends of the rotor spokes 3, respectively. A plurality of inflow holes 4 are arranged on the inner diameter side of each end plate 5 . A rotor rim 7 is arranged on the outer peripheral side of the rotor spokes 3 . The rotor rim 7 is composed of a plurality of steel plates or the like laminated in the axial direction of the rotor, and a rim duct 8 serving as a passage for cooling gas is provided in a portion of the rotor rim 7 . A plurality of poles 9 are arranged on the outer peripheral side of the rotor rim 7 at intervals in the circumferential direction, and a rotor coil 10 is wound around each pole 9 . The stator 62 described above is arranged outside the rotor 61 configured in this manner.

In this rotating electric machine, as a method for cooling the inside of the machine, a radial ventilation system is adopted in which the cooling gas 6 is circulated by the action of a centrifugal fan accompanying the rotation of the structure attached to the rotor shaft 1 and the rotor 61. 6 flows into the rotor spoke mechanism 2 through a plurality of inflow holes 4 provided in the end plate 5 , and then moves in the outer peripheral direction within the rotor spoke mechanism 2 to reach a rim duct 8 provided in the rotor rim 7 . and flows out between the poles 9 to cool the rotor coil 10 at the same time.

As shown in FIGS. 1 to 3, the rotor of the rotating electric machine according to the present embodiment includes a ventilation guide 14 attached to the rotor rim 7 from the outer diameter side of the rotor by, for example, a ventilation guide support 15. . By installing the ventilation guide 14 , two flow paths P are formed between the poles 9 .

In this ventilation guide 14, the cooling gas flowing out between the poles 9 from the rim duct 8 branches in the rotor circumferential direction between the poles 9 and flows into the two flow paths P, respectively, and flows into the wall surfaces (rotational flow paths) of the poles 9 on both sides. The cooling gas is guided so as to flow radially outward along the wall surface of the child coil 10 .

According to this embodiment, by providing the ventilation guide 14 between the poles 9, the cooling gas flowing out from the rim duct 8 is branched between the poles 9 in the rotor circumferential direction, and the wall surfaces of the poles 9 on both sides (rotor (including the walls of the coil 10). Therefore, the rotor coil 10 can be efficiently cooled. In addition, in the conventional structure, there was one large space between the individual poles 9. As the rotor rotates, the cooling gas flows in a complex manner, causing vortices and the like, resulting in ventilation loss. However, in this embodiment, the cooling gas flow is rectified by installing the ventilation guide 14, so that no large vortex is generated, ventilation loss can be reduced, and efficient cooling can be performed.

(First modification)
FIG. 4 is a radial cross-sectional view showing a first modification to the structure shown in FIG.

In the ventilation guide 14 according to this first modification, the gap between the wall surface of each of the poles 9 on both sides (including the wall surface of the rotor coil 10) and the wall surface of the ventilation guide 14 facing each other is the inner diameter side of the rotor. It has a shape that widens toward the outer diameter side.

By installing the ventilation guide 14 in this way, the flow passage area of the flow passage P increases from the inner diameter side to the outer diameter side of the rotor. It is possible to reduce the confluence loss that occurs when the cooling gas merges with the cooling gas in the air gap G that rotates at high speed as the rotor rotates. Such a structure of the ventilation guide 14 has a large effect of reducing ventilation loss, and is effective when it is desired to increase the amount of cooling gas circulating inside the machine while obtaining a sufficient cooling effect of the rotor coil 10. .

(Second modification)
FIG. 5 is a radial cross-sectional view showing a second modification to the structure shown in FIG.

In the ventilation guide 14 according to the second modification, the gap between the wall surface of each of the poles 9 on both sides (including the wall surface of the rotor coil 10) and the opposing wall surface of the ventilation guide 14 is the inner diameter side of the rotor. It has a shape that becomes narrower as it goes from to the outer diameter side.

By installing the ventilation guide 14 in this way, the flow passage area of the flow passage P becomes smaller from the inner diameter side to the outer diameter side of the rotor. Since the width of the flow path is narrowed to the side, the cooling gas can easily flow along the wall surface of the rotor coil 10, and the rotor coil 10 can be cooled more efficiently. Such a structure of the ventilation guide 14 is effective when it is desired to further improve the cooling effect of the rotor coil 10 .

[Second embodiment]
Next, a second embodiment will be described with reference to FIGS. 6 to 9. FIG. In addition, the same reference numerals are assigned to elements that are common to the respective drawings described above, and overlapping descriptions are omitted. The following description will focus on the parts that are different from the first embodiment.

FIG. 6 is a radial cross-sectional view showing the structure of part of the rotor of the rotary electric machine according to the second embodiment, and FIG. 7 is a perspective view showing the shape of the ventilation guide shown in FIG.

In the ventilation guide 14 according to the second embodiment, at least the wall surface on the rotation direction side of the rotor is , and a plurality of protrusions 16 are provided.

Without the plurality of protrusions 16 , the cooling gas in the flow path P on the rotation direction side of the ventilation guide 14 becomes a flow biased toward the wall surface side of the ventilation guide 14 due to the rotation of the rotor, and the wall surface side of the rotor coil 10 . Since a separated flow occurs at , improvement in the cooling effect of the rotor coil 10 is hindered. On the other hand, in the present embodiment, since a plurality of protrusions 16 are provided on the wall surface of the ventilation guide 14 on the rotation direction side, the wall surface of the ventilation guide 14 in the flow path P on the rotation direction side of the ventilation guide 14 The cooling gas flowing through the rotor collides with the plurality of projections 16 to promote turbulent flow and generate a flow of cooling gas toward the wall surface of the rotor coil 10 facing the wall surface of the ventilation guide 14 . cooling effect is improved.

In this example, the shape of the protrusion 16 is illustrated as a triangular pyramid shape, but other shapes such as a cone shape and other pyramids may be used as long as they protrude from the wall surface. Moreover, the cooling effect of the rotor coil 10 can be improved.
In this example, the projections 16 are provided only on the wall surface on the rotation direction side. A gas flow is generated and the cooling effect of the rotor coil 10 is improved.

(Modification)
FIG. 8 is a radial cross-sectional view showing a modification to the structure shown in FIG.

In the ventilation guide 14 according to this modification, a plurality of projections 16 are arranged in a zigzag pattern in the axial direction or radial direction of the rotor, or in both directions. In the example illustrated in FIG. 8, the plurality of protrusions 16 are not aligned in the radial direction of the rotor, but arranged in a zigzag pattern in the radial direction of the rotor.

By arranging a plurality of protrusions 16 in a zigzag manner in this way, the cooling gas 6 flowing into the wall surface side of the ventilation guide 14 narrows the distance between the protrusions 16 and collides with the individual protrusions 16. Turbulent flow is further promoted, and the cooling effect of the rotor coil 10 is further enhanced.

[Third embodiment]
Next, a third embodiment will be described with reference to FIGS. 9 and 10. FIG. In addition, the same reference numerals are assigned to elements that are common to the respective drawings described above, and overlapping descriptions are omitted. The following description will focus on the parts that are different from the second embodiment.

9 is a perspective view showing the shape of the ventilation guide according to the third embodiment, and FIG. 10 is a side view of the rotor including the ventilation guide shown in FIG. 9 as seen from the rotor outer diameter side.

In the ventilation guide 14 according to the third embodiment, the gap between the wall surfaces of the poles 9 on both sides (including the wall surface of the rotor coil 10) and the wall surface of the ventilation guide 14 facing each other is set at both ends in the rotor axial direction. It has a shape that widens from the center toward the center.

By installing the ventilation guides 14 in this way, the flow area of the two flow paths P formed between the poles 9 increases from both ends toward the center in the axial direction of the rotor. Therefore, the cooling gas flowing on both outer sides of each pole 9 in the axial direction of the rotor flows into the two flow paths P between the poles 9 and flows toward the center of the axial direction of the rotor between the poles 9 and from the rim duct 8. It joins with the cooling gas flowing out due to the rotation centrifugal force, and the cooling gas flow rate increases.

According to this embodiment, the cooling gas flow rate between the poles 9 can be increased due to the structure in which the flow area of the flow path P increases from both ends of the pole 9 in the rotor axial direction toward the center. In addition, since the cooling gas flowing through the flow path P is restrained from being directed to both outer sides of each pole 9 in the axial direction of the rotor, the axial flow velocity distribution of the cooling gas 6 becomes substantially uniform, and the rotor coil 10 is distributed substantially uniformly. , and the cooling effect of the rotor coil 10 can be further improved.

As described in detail above, according to each embodiment, it is possible to efficiently cool the rotor coil while reducing the ventilation loss of the rotating electric machine.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1... Rotor shaft 2... Rotor spoke mechanism 3... Rotor spoke 4... Inflow hole 5... End plate 6... Cooling gas 7... Rotor rim 8... Rim duct 9... Pole 10... Rotor coil 14 Ventilation guide 15 Ventilation guide support 16 Protrusion F Flow of cooling gas P Flow passage.

Claims (6)

a rotor shaft; rotor spokes provided on the outer peripheral side of the rotor shaft; a rotor rim having a rim duct provided on the outer peripheral side of the rotor spokes and serving as a cooling gas passage; and an outer periphery of the rotor rim. A rotor for a rotating electric machine, comprising: a plurality of poles arranged on the side and spaced apart in the circumferential direction; and rotor coils respectively provided on the plurality of poles,
A ventilation guide is provided for guiding the cooling gas flowing out from the rim duct between the poles so that the cooling gas flows between the poles in the circumferential direction of the rotor and flows along the wall surfaces of the poles on both sides toward the outer diameter side. , the rotor of a rotating electric machine. 2. The ventilation guide according to claim 1, wherein the gap between the wall surface of each of the poles on both sides and the wall surface of the ventilation guide facing each other has a shape that widens from the inner diameter side to the outer diameter side of the rotor. rotating electric machine rotor. 2. The ventilation guide according to claim 1, wherein the space between the wall surfaces of the poles on both sides and the opposing wall surface of the ventilation guide becomes narrower from the inner diameter side to the outer diameter side of the rotor. rotating electric machine rotor. 4. The ventilation guide according to any one of claims 1 to 3, wherein, of the two wall surfaces facing the wall surfaces of the poles on both sides, at least the wall surface on the rotating direction side of the rotor has a plurality of projections. 1. A rotor of a rotary electric machine according to claim 1. 5. The rotor of a rotary electric machine according to claim 4, wherein said plurality of projections are arranged in a zigzag pattern in the axial direction, radial direction, or both directions of said rotor. 6. The ventilation guide has a shape in which the distance between the wall surface of each of the poles on both sides and the wall surface of the ventilation guide facing each other increases as it goes from both ends toward the center in the axial direction of the rotor. The rotor of the rotary electric machine according to any one of 1.

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