JP2013034332A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine which enhances cooling of a stator coil end without requiring an unnecessary margin of a cooling air quantity.SOLUTION: Providing means for guiding cooling air from a cooler 10 from the axial inner side of a stator coil end 8 to the outer side allows the stator coil end 8 to be cooled with all the air quantity of the cooling air passing the cooler 10. Thus, the cooling of the entire stator coil end 8 is enhanced. Further, since it is not necessary to adjust the air quantity distribution of the cooling air which is distributed to the stator coil end 8, the design of the ventilation structure becomes easy.

Description

  The present invention relates to a ventilation structure of a rotating electrical machine, and more particularly to a rotating electrical machine suitable for a ventilation system in which cooling air is driven by axial fans at both ends of a rotating shaft of a rotor.

  Generally, in a rotating electrical machine such as a generator, it is necessary to cool the coils and iron cores of the rotor and the stator, and a cooling structure for this purpose is provided. As a typical cooling structure in such a rotating electric machine, there is a system in which an axial fan is attached to a rotor shaft to drive cooling air.

  As an example, FIG. 5 shows a schematic configuration of a turbine generator. The rotating electrical machine 1 in FIG. 5 includes a rotor 2 and a stator 3. An axial fan 5 is provided at both ends of the shaft 4 of the rotor 2. The cooling air from the axial fan 5 is divided into a flow 6 a toward the inside of the rotor 2, a flow 6 b toward the air gap 7, and a flow 6 c toward the stator coil end 8. The flow 6 a toward the inside of the rotor 2 cools the rotor, and then merges with the flow 6 b toward the air gap 7 to cool the stator and flows into the stator frame 9. The flow 6c toward the stator coil end 8 cools the stator coil end 8 and then flows into the stator frame 9 to merge with other cooling air. The cooling air flowing out from the outer periphery of the stator frame 9 is removed by the cooler 10, passes through the ventilation path 13 formed by the casing 11 and the guide plate 12, and returns to the axial fan 5.

  In general, the air flow distribution of the flows 6a, 6b, and 6c exiting the axial fan is designed so that the air flow resistance of the flow passage of the flow 6c can be ensured from the amount of heat generated from the stator coil end 8. ing. However, since the stator coil end 8 has a complicated shape and is difficult to cool uniformly, the coil temperature may locally increase. In order to prevent this, it was necessary to increase the air flow rate of the flow 6c to obtain a margin.

  As a method for enhancing the cooling of the stator coil end without increasing the air flow rate of the flow 6c more than necessary, for example, as described in Examples of Patent Document 1 and Patent Document 2, the guide plate 12 is used more than usual. A method is disclosed in which the outer end of the stator coil end is partly projected into the ventilation path by being installed inside in the axial direction. According to this method, the outer end portion of the stator coil end is cooled by the total amount of low-temperature cooling air that has come out of the cooler, so that the temperature of the stator coil end can be lowered.

Japanese Utility Model Publication No. 51-137501 JP 58-89046 A

  In the above-described prior art, cooling of the coil end is enhanced by directly cooling a part of the stator coil end with cooling air from the cooler. However, since the remaining portion of the stator coil end is still cooled by the flow 6c obtained by diverting the cooling air from the axial fan, it cannot be uniformly cooled and the coil temperature is locally high. There was a problem of becoming.

  That is, the problem to be solved by the present invention is to provide a rotating electrical machine in which cooling of the stator coil end is enhanced without requiring a useless margin of the cooling air volume.

  In order to achieve the above object, the rotating electrical machine of the present invention is provided with means for guiding cooling air from the cooler from the axially inner side to the outer side of the stator coil end.

  In other words, a stator and a rotor disposed inside the stator via an air gap are provided, and a plurality of stators are disposed on the inner peripheral side of the stator at predetermined intervals in the circumferential direction. A coil coil and a stator coil provided in the coil slot, the stator coil forming an end portion that protrudes substantially along the rotation axis direction of the rotor, and the rotor shaft A rotating electrical machine in which axial fans are installed at both ends includes means for guiding cooling air from an air cooler from the axially inner side to the outer side of a stator coil end portion.

  According to the present invention, since the stator coil end is cooled by the total air volume passing through the cooler, the cooling of the entire stator coil end can be enhanced. In addition, since it is not necessary to adjust the air volume distribution of the cooling air diverted to the stator coil end, the design of the ventilation structure is simplified.

It is explanatory drawing of the 1st Example of the rotary electric machine of this invention. It is explanatory drawing of the modification of the 1st Example of the rotary electric machine of this invention. It is explanatory drawing of the 2nd Example of the rotary electric machine of this invention. It is explanatory drawing of the example of a combination of the 1st Example of the rotary electric machine of this invention, and a 2nd Example. It is explanatory drawing which shows the conventional rotary electric machine.

  Hereinafter, examples will be described with reference to the drawings.

  A first embodiment of a rotating electrical machine according to the present invention will be described with reference to FIG. The schematic configuration of the first embodiment is substantially the same as the conventional example described above except for the stator coil end ventilation structure, and the description thereof is omitted here.

  In this embodiment, the means for guiding the cooling air from the cooler from the inner side to the outer side in the axial direction of the stator coil end is constituted by two kinds of guide plates. First, the first guide plate 14 guides the cooling air that has flowed out of the cooler 10 to the upper portion of the casing 11 to the inside of the stator coil end in the axial direction. Next, the air is guided to the second guide plate 15 installed close to the inner diameter side of the stator coil end 8, and the cooling air flows axially outward along the stator coil end. At this time, the stator coil end is cooled by the total air volume that has passed through the cooler. The cooling air that has passed through the stator coil end 8 changes its direction toward the inner diameter side along the casing 11 and heads toward the inlet of the axial fan 5. In the embodiment, the axially outer end of the second guide plate 15 has a bell mouth shape so that the cooling air toward the fan inlet smoothly changes direction. Thereby, ventilation loss can be suppressed small. The second guide plate 15 also plays a role of guiding the flow of cooling the stator coil end to the inlet of the axial fan 5. Without the second guide plate 15, the cooling air that has cooled the stator coil end is directed to the outlet side of the axial fan, so that the ventilation structure is not established.

  The cooling air that has exited the axial fan 5 is divided into two flows, a flow 6 a that goes into the rotor and a flow 6 b that flows into the air gap 7. Conventionally, the flow is divided into three, including the flow to the stator coil end, but it is reduced to two, which simplifies the design of the ventilation structure that determines the distribution of the divided flow.

  FIG. 2 shows a second embodiment of the rotating electrical machine according to the present invention. In the present embodiment, the second guide plate 15 has a substantially truncated cone shape that extends along the inner diameter side of the upper coil 8a of the stator coil end and expands outward in the axial direction. With such a configuration, the outer diameter of the axial fan can be increased, which can be applied when a larger air volume is required.

  According to the present embodiment described above, the stator coil end is cooled by the total air volume that passes through the cooler, so that the cooling of the stator coil end can be enhanced. Further, since the cooling air that has passed through the stator coil end cools the rotor and the stator downstream thereof, there is no useless margin even if the amount of air that cools the stator coil end is large.

A third embodiment of the rotating electrical machine according to the present invention will be described with reference to FIG.
In the present embodiment, the second guide plate 15 is installed between the upper coil 8a and the bottom coil 8b of the stator coil end. According to such a configuration, since the second guide plate 15 is limited to the area inside the stator coil end 8, it is possible to ensure a wide ventilation path without occupying the ventilation area of the cooling air. it can. Further, the strength can be improved by integrating the stator coil end 8 and the second guide plate 15 into an integral structure.

  In the case of the present embodiment, the bottom coil 8b at the stator coil end is cooled by cooling air that is outward in the axial direction, but the upper coil 8a flows inward in the axial direction after exiting the axial fan 5. It is cooled by. However, the feature that the shunt flow of cooling air (6c in FIG. 5) required for cooling the stator coil end required in the conventional example is not necessary is the same as that in the first embodiment.

  Furthermore, in this embodiment, the shape of the insulating cap 16 attached to the axially outer end of the stator coil end is extended to the inner diameter side so as to be close to the outer diameter position of the axial flow fan 5 at a predetermined interval. . Further, by making the shape of the insulating cap 16 from the outer side in the axial direction to the inner diameter side a bell mouth shape, the disturbance of the cooling air flowing into the axial fan 5 can be reduced and the ventilation loss can be reduced. .

A fourth embodiment of the rotating electrical machine according to the present invention will be described with reference to FIG.
In the present embodiment, the insulating cap 16 also serving as the bell mouth on the inlet side of the axial fan is used in combination with the second guide plate 15 installed between the upper coil 8a and the bottom coil 8b of the stator coil end. However, it is naturally possible to combine with the second guide plate installed on the inner side of the stator coil end as described in the first embodiment, and this embodiment does not limit the combination. In the latter combination, in the rotating electrical machine having the insulating cap at the stator coil end, the shape of the second guide plate can be simplified by using the insulating cap also as the bell mouth on the axial flow fan inlet side. .

  An example of such a combination is shown in FIG. In the present embodiment, the shape of the second guide plate 15 is simplified to a simple cylindrical shape with a flange by using the insulating cap 16 also as a bell mouth at the inlet of the axial flow fan.

DESCRIPTION OF SYMBOLS 1 Rotating electric machine 2 Rotor 3 Stator 4 Shaft 5 Axial fan 6 Arrow which shows the flow of the cooling air from an axial fan 7 Air gap 8 Stator coil end 9 Stator frame 10 Cooler 11 Casing 12 Guide plate 13 Casing 11 and a guide plate 12 for a ventilation path 14 First guide plate 15 Second guide plate 16 Insulation cap

Claims (6)

A coil including a stator and a rotor disposed inside the stator via an air gap, and a plurality of coils arranged at predetermined intervals in the circumferential direction on the inner circumferential side of the stator And a stator coil provided in the coil slot, the stator coil forming a stator coil end protruding along a rotation axis direction of the rotor, and both ends of the rotor shaft In the rotating electrical machine equipped with an axial fan and equipped with a cooler that removes the cooling air circulating inside,
A rotating electrical machine comprising means for guiding cooling air from the cooler from the axially inner side to the outer side of the stator coil end.   The means for guiding the cooling air from the cooler includes a first guide plate that guides the cooling air to the inner side in the axial direction of the stator coil end, and the cooling air guided to the inner side in the axial direction of the stator coil end. The rotating electrical machine according to claim 1, comprising a second guide plate that leads to an axially outer side of the stator coil end.   3. The rotating electrical machine according to claim 2, wherein the second guide plate is installed in a cylindrical shape adjacent to an inner peripheral side of the stator coil end.   The second guide plate installed in a cylindrical shape close to the inner peripheral side of the stator coil end smoothly redirects the flow of cooling air toward the axial fan inlet. The rotating electrical machine according to claim 3, wherein the rotating electrical machine has a bell mouth shape.   The rotating electrical machine according to claim 2, wherein the second guide plate is installed between an upper coil constituting an inner diameter side of the stator coil end and a bottom coil constituting an outer diameter side.   An insulating cap installed at the outer end of the stator coil end in the axial direction is extended toward the inner diameter side so as to be close to the outer diameter position of the axial fan with a predetermined gap, and cooled toward the inlet of the axial fan. The rotating electrical machine according to any one of claims 2 to 5, wherein the rotating electric machine has a bell mouth shape from an outer side in an axial direction to an inner diameter side in order to smoothly turn a wind flow.