JPS6337588B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a large salient pole rotating electrical machine such as a water turbine generator, and more particularly to a salient pole rotating electrical machine with good ventilation cooling of a stator core.

A conventional salient pole rotating electrical machine such as a water turbine generator is shown in FIG. In the figure, 50 is a rotor and 60 is a stator. The rotor 50 is mainly formed by a rotating shaft 1 , a spider 2 , a yoke 3 , a salient magnetic pole 4 , and a field coil 5 . Reference numeral 6 denotes a pole-to-pole closing plate, which is attached for the purpose of closing the pole-to-pole gap between the salient magnetic poles 4 and reducing windage loss.
This closing plate can be attached over the entire length of the salient magnetic pole in the axial direction (the entire length in this figure), or it can be provided on a portion of the salient pole in the axial direction. The stator 60 mainly includes a stator coil 7, a stator core 8, a stator ventilation guide 9 for passing air to cool the stator core 8, and a stator frame 10.
Further, on the outer circumferential side of the stator, a first blower 1 is installed for forcing air to pass between the salient magnetic poles 4 and cool the field coil 5 and the iron core.
1. A second blower 12 that exclusively cools the iron core 8 and coil 7 on the stator side, a cooler 13 that cools the air that is heated while passing through the generator, and exhaust and intake air from the stator core bag. A ventilation box 14 for collecting cooling air and a ventilation guide 15 for guiding cooling air into the rotating electric machine are provided. In addition,
The second blowers 12 and coolers 13 are arranged alternately in the circumferential direction as shown in FIG.
In FIG. 2, 16 is a slot for housing the stator coil, and 17 is a duct piece for forming the ventilation duct 9.

Next, the flow of cooling air, which is a cooling medium, in this configuration will be explained using FIG. 1. First, to cool the field coil 5, which is the heating element on the rotor side, cooling air is sent into the generator by the first blower 11 as shown by the arrow in the figure, and this cooling air is suddenly The field coil is cooled by penetrating between the poles of the magnetic poles 4 in the axial direction, and is then collected in the air collection box 14, from where it is discharged via the cooler 13 to the air duct outside the machine. On the other hand, cooling air for cooling the stator side is sent to the back of the stator by the second blower 12, as shown by the arrow in the figure, and then exits through the stator ventilation duct 9 to the air gap. It then changes direction (turns around) in the air gap and is discharged to the outside air passage through the exhaust ventilation duct and cooler 13. However, in this structure, the wind speed distribution and temperature distribution in the stator ventilation duct are It will look like Figure 3. In FIG. 3, V is a curve showing the wind speed distribution state in each section, and θ is a curve showing the temperature distribution state.
The intake section P and the exhaust section Q are separated by a partition plate 18. In this case, as is clear from the temperature distribution curve θ, the partition plate 18 airtightly partitions the intake section P and the exhaust section Q. The temperature of the stator core becomes the highest.
In addition, the iron core in this part is cooled by the low-temperature inlet air on one side of the axial intake section side, and by the exhaust air whose temperature has risen due to cooling on the other side of the exhaust section side, so the iron core temperature during load operation is The temperature is low on the intake section side and high on the exhaust section side, creating a temperature gradient along the axial direction (thickness direction) around the core. In proportion to this temperature gradient, the amount of radial heat expansion in the stator core increases from the inlet section (low temperature) side to the exhaust section (high temperature) side, so for a similar reason to bimetal,
The iron core of the partition plate part undergoes thermal deformation such that the outer circumferential side thereof bends in the stacking thickness direction as indicated by the dotted line in FIG. For this reason, the passage of the cooling air in the air inlet A shown in the figure is narrowed, and the air volume is reduced. As a result, the temperature of the stator core in the narrowed portion increases, further increasing thermal elongation. After this cycle is repeated, local heating of the stator core in the thermal expansion zone is induced.
It had the drawback of causing a burnout accident.

The present invention has been made in view of the above points,
Therefore, the object is to provide a salient pole rotating electric machine having a stator core that is free from local heating.

That is, the present invention achieves the intended purpose by providing an outwardly expanding notch at the cooling air inlet/outlet portion of the ventilation duct adjacent to the partition plate.

The present invention will be explained below based on the illustrated embodiments. An embodiment of the present invention is shown in FIGS. 5 and 6. Note that parts that are the same as those in the conventional model are given the same reference numerals, and therefore their explanations will be omitted. As is clear from the figure, the inlet/outlet portion of the cooling air of the ventilation duct adjacent to the partition plate 18 is widened, that is, notches C that extend outward are provided at all four corners of the stator core 19. . By doing so, even if the iron core is deformed due to thermal elongation, the entrance area of the stator ventilation duct 20 will not be narrowed. Therefore, there is no reduction in the amount of cooling air passing through the ventilation duct at the shaft end of the intake section.

In addition, the corners of the core at the inlet and outlet of the ventilation duct that cools the iron core in the partition plate section are cut out and widened all around the circumference, so that the ventilation ducts located on both sides of the stator core in the partition plate section in the axial direction are ventilated. The resistance is significantly reduced and the ventilation volume of the ventilation duct in this area is also increased. The effect of preventing the entrance area from being reduced by the notches provided in the core of the partition plate part has the advantage that it can be achieved without increasing the axial dimension of the stator core as a whole, as would be the case when increasing the overall duct width. be.

With such a configuration, both the air volume distribution and temperature distribution of the stator core are averaged as shown in FIG. Therefore, local heating due to thermal expansion of the stator core adjacent to the partition plate does not occur.

As described above, the present invention widens the cooling air inlet/outlet portion of the ventilation duct adjacent to the partition plate.
Shrinkage of the ventilation duct due to thermal elongation of the stator core is prevented, an increase in air volume is ensured, and a salient pole rotating electric machine having a stator core without local heating can be obtained.

[Brief explanation of the drawing]

Figure 1 is a vertical side view of a conventional salient pole rotating electrical machine.
Fig. 2 is a partial perspective view of the stator of the salient pole type rotating electric machine, Fig. 3 is a characteristic diagram showing the wind speed and temperature distribution at each inlet/exhaust section of the stator core, and Fig. 4
The figure is a partial longitudinal side view showing changes due to thermal expansion of the stator core exposed to the intake and exhaust air, and FIG. 5 is a longitudinal side view of a salient pole type rotating electric machine stator showing an embodiment of the present invention. FIG. 6 is a partial vertical side view of the stator core exposed to the intake and exhaust air, and FIG. 7 is a characteristic diagram of wind speed and temperature distribution in the intake and exhaust sections of the stator core. 7... Stator coil, 8... Stator core, 9...
...Stator ventilation duct, 10...Stator frame, 18...
...Partition plate, 50...Rotor, 60...Stator,
C... Notch.

Claims (1)

[Claims] 1. A stator core supported by a stator frame and having ventilation ducts extending in the radial direction and arranged at predetermined intervals in the axial direction; The stator includes a stator having a stator coil and a rotor disposed opposite to the stator with a solid gap therebetween, and a plurality of ventilation ducts provided at intervals in the axial direction of the stator core. The stator core is divided into an intake section and an exhaust section by a plurality of partition plates provided between the stator core and the stator frame, and in the intake section, the outer diameter side of the stator core is inserted into the ventilation duct. Cooling air is made to flow from the stator core toward the inner diameter side, and in the exhaust section, the cooling air is turned back at the gap between the rotor and the stator core so that it is ventilated from the inner diameter side to the outer diameter side of the stator core. In the salient pole rotating electrical machine configured to cool the stator core, a notch extending outward is provided around the entire circumference of the cooling air inlet/outlet portion of the ventilation duct adjacent to the partition plate. A salient pole type rotating electrical machine featuring: