JP2001178080A - Cooling structure for rotor winding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling structure for dynamoelectric machine which can enhance the cooling efficiency, by circulating a cooling medium satisfactorily. SOLUTION: Each cooling groove 13 in the centrifugal direction is inclined, in the stream direction of a cooling medium in an axial cooling groove 12, with respect to the axial cooling groove 12 which extends axially within a rotor iron core 1, and also the section branching from the axial cooling groove 12 to the centrifugal cooling grooves 13 is made into a circular curve 14, whereby this structure can reduce the pressure loss in both cooling grooves 12 and 13, and also can easily discharge mixed-in foreign matters to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for a rotor winding, and is particularly useful when applied to a rotor of a large rotating electric machine such as a generator rotor.

[0002]

2. Description of the Related Art Since a large Joule heat is generated in a rotor winding of a generator rotor, it is necessary to effectively remove the Joule heat. In this type of generator rotor winding cooling structure, heat loss generated in the rotor winding is transmitted from the outer surface of the rotor winding to the cooling medium and is dissipated. Here, the lost heat must flow through the insulation of the windings, the gaps, the rotor teeth before being removed by the cooling medium at the cooling grooves of the rotor or at the surface of the rotor. In direct cooling, the lost heat generated in the rotor windings is removed directly from the cooling surface of the rotor windings into the cooling medium. Such a direct cooling method,
Almost all of them are used in large-capacity generators.

FIG. 3A is a diagram showing a cooling structure for a rotor winding according to the prior art. The figure is shown together with the generator rotor shown partially cut away. FIG.
(B) is a transverse sectional view showing the slot portion. As shown in both figures, the cooling structure has an axial cooling groove 2 which is a slot bottom groove extending in the axial direction of the rotor core 1 and is continuous with and perpendicular to the axial cooling groove 2. It has a number of centrifugal cooling grooves 3 extending in the centrifugal direction. In such a cooling structure, the cooling medium (gas) taken in from both ends of the rotor winding 4 flows toward the center of the rotor through the axial cooling grooves 2, and each of the centrifugal cooling grooves punched in the copper conductor. Go outside through 3. The flow direction of the cooling medium at this time is indicated by an arrow in the figure.

[0004]

In the cooling structure according to the prior art as described above, since each centrifugal cooling groove 3 is formed at right angles to the axial cooling groove 2, the cooling medium is cooled in the axial cooling direction. When the flow direction is changed so as to flow into each centrifugal cooling groove 3 from the groove 2, a large pressure loss occurs, and dust adheres to a branch portion from the axial cooling groove 2 to the centrifugal cooling groove 3. There is a problem that the axial cooling groove 2 or the centrifugal cooling groove 3 is gradually closed to increase the flow resistance of the cooling medium.

SUMMARY OF THE INVENTION In view of the above prior art, an object of the present invention is to provide a cooling structure for a rotating electric machine winding that can improve the cooling efficiency by circulating a cooling medium well.

The structure of the present invention that achieves the above object has the following features.

[0007] 1) An axial cooling groove extending in the axial direction inside the rotor core, and a plurality of cooling grooves which are continuous with the axial cooling groove, extend in the centrifugal direction of the rotor core, and open to the surface of the rotor core. And with a centrifugal cooling groove of
In the cooling structure of the rotor winding configured to allow the cooling medium to flow through the axial cooling grooves, and then to flow through each centrifugal cooling groove and to be discharged to the outside from each opening, each centrifugal cooling groove is The cooling medium in the directional cooling groove is inclined in the flow direction.

[0008] 2) An axial cooling groove extending in the axial direction inside the rotor core, and a plurality of cooling grooves that are continuous with the axial cooling groove, extend in the centrifugal direction of the rotor core, and open to the surface of the rotor core. And with a centrifugal cooling groove of
In the cooling structure of the rotor winding configured to allow the cooling medium to flow through the axial cooling grooves, and then to flow through each centrifugal cooling groove and to be discharged to the outside from each opening, each centrifugal cooling groove is The cooling medium is inclined in the direction of flow of the cooling medium in the direction cooling groove, and at least a portion on the downstream side with respect to the direction of flow of the cooling medium in the confluence of the axial direction cooling groove and each of the centrifugal direction cooling grooves has an arcuate curved portion. thing.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1A is a diagram showing a cooling structure for a rotor winding according to an embodiment of the present invention. The figure is shown together with the generator rotor shown partially cut away.
As shown in the figure, the cooling structure according to the present embodiment also has an axial cooling groove 12 and a large number of centrifugal cooling grooves 13 branched from the axial cooling groove 12, similarly to the cooling structure shown in FIG. However, the angle of each centrifugal cooling groove 13 with respect to the axial cooling groove 12 is different. That is, each centrifugal cooling groove 13 is inclined in the flow direction of the cooling medium in the axial cooling groove 12. In addition, FIG.
As shown in the enlarged and extracted portion A of FIG.
Of the confluence of the cooling medium 2 and the centrifugal cooling grooves 13 on the downstream side with respect to the flow direction of the cooling medium, the arc-shaped curved portion 1
4 is formed. Note that the same parts as those in FIG. 3 are denoted by the same reference numerals, and redundant description will be omitted.

According to this embodiment, the cooling groove 1 in the centrifugal direction is provided.
3 is inclined with respect to the axial cooling groove 12, and since the inclined direction is the flow direction of the cooling medium, the pressure loss in both cooling grooves 12, 13 is reduced as compared with the conventional case, and the cooling medium can be cooled well. Distribution can be guaranteed. By inclining the cooling groove 13 in the centrifugal direction, as shown in FIG. 2, an axial passage formed by a gap between the rotor core 1 and the stator core 15 and a centrifugal The cooling medium can be caused to flow evenly into the stator cooling grooves 16 provided in the cooling medium. Furthermore, even when foreign matter such as dust enters the centrifugal cooling groove 13, the foreign matter can be satisfactorily discharged to the outside, and an increase in flow resistance due to the mixture and stagnation of the foreign matter can be eliminated.

In the above-described embodiment, the arc-shaped curved portion 14 is formed at a portion downstream of the converging portion with each of the cooling grooves 13 in the flow direction of the cooling medium. It is not necessary to form the curved portion 14 as described above. Even if the cooling groove 13 in the centrifugal direction is merely inclined, good circulation of the cooling medium is guaranteed. Conversely, a similar curved portion 14 may be formed in an upstream portion in the flow direction of the cooling medium. In this case, the foreign matter mixed in the cooling groove 13 in the centrifugal direction can be discharged more favorably.

[0013]

As described in detail with the above embodiments, according to the present invention, the pressure loss in the cooling groove can be reduced favorably, and the cooling medium can be evenly distributed in the inside of the stator and the gap between the stators. Since it can be distributed, the winding can be efficiently cooled. Furthermore, in the case where a curved portion is formed at a branch portion from the axial cooling groove to the centrifugal cooling groove, even if foreign matter is mixed in, the foreign matter can be satisfactorily discharged to the outside. Clogging can be prevented, which can also improve overall cooling efficiency.

[Brief description of the drawings]

1A and 1B are diagrams showing a cooling structure of a rotor winding according to an embodiment of the present invention, in which FIG. 1A is a perspective view showing the cooling structure together with a generator rotor, and FIG. It is an enlarged view which extracts and expands.

FIG. 2 is an explanatory diagram for explaining the operation and effect of the cooling structure shown in FIG.

3A and 3B are diagrams showing a cooling structure of a rotor winding according to a conventional technique, in which FIG. 3A is a perspective view showing the cooling structure together with a generator rotor, and FIG. 3B is a cross-sectional view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor core 12 Axial cooling groove 13 Centrifugal cooling groove 14 Curved part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H002 AD04 5H603 AA11 BB02 BB12 CA04 CB02 CC03 CD02 CD21 CE01 5H609 BB03 BB12 PP02 PP07 PP08 PP09 QQ12 QQ13 QQ18 RR06 RR16 RR36 RR37 RR42 RR43 RR44 RR69 RR73

Claims (2)

[Claims] An axial cooling groove extending in an axial direction inside a rotor core, and a plurality of cooling grooves that are continuous with the axial cooling groove, extend in a centrifugal direction of the rotor core, and open to the surface of the rotor core. And a cooling structure for the rotor winding, wherein the cooling medium flows through the axial cooling grooves, and then flows through the centrifugal cooling grooves and is discharged from each opening to the outside. 3. The cooling structure for a rotor winding according to claim 1, wherein each of the centrifugal cooling grooves is inclined in a flow direction of the cooling medium in the axial cooling groove. 2. An axial cooling groove extending in the axial direction inside the rotor core, and a plurality of cooling grooves that are continuous with the axial cooling groove, extend in the centrifugal direction of the rotor core, and open on the surface of the rotor core. And a cooling structure for the rotor winding, wherein the cooling medium flows through the axial cooling grooves, and then flows through the centrifugal cooling grooves and is discharged from each opening to the outside. In the above, each centrifugal cooling groove is inclined in the flow direction of the cooling medium in the axial cooling groove, and at least the downstream side of the confluence of the axial cooling groove and each centrifugal cooling groove with respect to the flow direction of the cooling medium. A cooling structure for a rotor winding, wherein the portion is an arc-shaped curved portion.