JPH0216099B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotor for a rotating electrical machine that reduces ventilation power loss and improves efficiency.

Hereinafter, a salient pole rotor of a rotating electrical machine such as a synchronous machine will be explained as an example.

A salient pole rotor of a conventional synchronous machine is shown in FIGS. 1 and 2 as a vertical sectional view and a partial plan sectional view. The figure shows the case of a vertical shaft type, where 1 is a rotating shaft, 2 is a rotor spider, and 3 is a rim that is firmly fixed to the rotor spider and forms a yoke for the rotor. Reference numeral 4 denotes a plurality of radial ventilation ducts provided on this rim, and ventilation intervals are formed by a plurality of duct pieces 5 and a spacing ring 6. 7 is a tightening bolt for the rim 3, and 8 is a nut. Reference numeral 10 denotes a plurality of salient pole-shaped magnetic pole cores made of laminated thin steel plates, which are tightened with tightening bolts and fixed to the outer periphery of the rim 3. 11 is the magnetic pole core 10
The field coil fitted in, 9 is the magnetic pole and the magnetic pole iron core 1
0 and a field coil 11. 12 is a fan attached to the rim 3.

Next, 13 is a stator frame, 14 is a stator core fixedly supported by this stator frame, and a radial ventilation duct 15 is provided. 16 is a stator coil, and 17 is an end enclosure. 18 is a rotor from 1 to
12, and 19 is a stator, which is made up of 13 to 17. 20 is an air gap formed between the rotor 18 and the stator 19.

In the conventional device described above, when the rotor 18 rotates, the cooling air introduced by the fan 12 cools the end of the field coil 11 and passes through the end of the stator coil 16 as shown by the arrow. Further, the cooling air that has entered the inner diameter side of the rotor spider 2 passes through the ventilation duct 4 and flows between adjacent field coils 11 as shown by the arrows to cool them. The cooling air passing between the field coils 11 is affected by the fan action of the salient poles and blown out into the air gap 20, passes through the stator ventilation duct 15, and cools the stator coil 16 and the stator core 14.

However, the mechanical loss (slip loss) of the rotor 18 is divided into wind loss and bearing loss, and wind loss consists of ventilation power loss, which is the power required for ventilation, and friction loss, which is consumed by friction with the surrounding air. It can be divided into However, in the above conventional configuration, the cooling air passing between the magnetic poles 9 is transferred to the rotor 1.
Air gap 2 remains with approximately the same angular velocity as 8.
0, and will be ejected into the air gap 20 with a large angular momentum. However, since the angular velocity becomes zero before passing through the air gap 20 and entering the ventilation duct 15 of the stator 19,
This large angular momentum almost directly results in ventilation power loss, which has the disadvantage that sufficient efficiency cannot be obtained.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and by tilting the direction of the cooling medium jetted from the rotor spider side to the air gap side in the opposite direction to the rotation direction of the rotor, It is an object of the present invention to provide a rotor for a rotating electrical machine that can reduce the ventilation power loss of a cooling medium ejected into an air gap and obtain sufficient efficiency.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a rotor of a rotating electrical machine according to an embodiment of the present invention will be described below with reference to the drawings. In FIGS. 3 and 4, numerals 1 to 20 are similar to the conventional device described above. Reference numeral 21 denotes a guide cover provided between the magnetic poles 9, which is provided over almost the entire length of the magnetic poles 9, has a wedge-shaped cross section in the direction perpendicular to the axis, and also covers the outer circumferential surface of the magnetic pole iron core 10 without protruding to the outer circumference of the rotor. together with the outer peripheral surface of the rotor 18, and the magnetic poles 9
When the cooling air that has passed through the gap is ejected into the air gap 20, it is configured to rotate in the opposite direction. A seal plate 22 is provided between the magnetic poles 9 to prevent cooling air flowing between the magnetic poles 9 from the ventilation duct 4 provided on the rim 3 from flowing out from above and below the magnetic poles 9.

The guide cover 21 is preferably made of a non-magnetic material that is free from overheating due to eddy currents since it is used in a high magnetic field, such as SUS304, SUS306, Al,
FRP (glass fiber reinforced plastic), thermosetting resin laminates, etc. are used.

In the above configuration, due to the rotation of the rotor 18,
As in the conventional case, the cooling air that has entered the inner diameter side of the rotor spider 2 passes through the ventilation duct 4 and flows between the adjacent field coils 11 to cool them. The cooling air passing between the magnetic poles 9 is affected by the fan action of the salient poles,
It is ejected from between the head of the magnetic pole core 10 and the guide cover 21 into the air gap 20 tilting in the opposite direction of rotation. The cooling air that has passed through the air gap 20 passes through the ventilation duct 15 of the stator 19 and reaches the stator coil 1.
6 and stator core 14 are cooled. Further, the circulation of cooling air by the fan 12 is the same as in the conventional device described above.

In this way, the cooling air blown into the air gap 20 from between the adjacent magnetic poles 9 flows through the guide cover 20.
Since the rotation is tilted in the opposite direction by , the angular velocity becomes smaller and the angular momentum becomes smaller. Therefore, the loss of ventilation power caused by this disappearing in the air gap 20 is reduced. To explain this principle with reference to FIG. 5, in the conventional device, the cooling air that passed between the magnetic poles 9 continued in the radial direction and was ejected into the air gap 20. The angle β ₁ formed by the relative velocity w ₁ of the air with the radial direction is close to 0°, and the circumferential velocity component u ₁ of the absolute velocity v ₁ is close to the circumferential velocity u of the rotor 18. By tilting the ejection direction in the opposite rotational direction by β ₂ using the guide cover 21 according to one embodiment, the angle that the relative speed w ₂ with respect to the peripheral speed u of the rotor 18 forms with the radial direction becomes β ₂ , and the absolute The circumferential velocity component u ₂ of the speed v ₂ can be considerably smaller than the circumferential velocity u of the rotor 18, and when the ventilation volume is the same,
Since the ventilation power is proportional to the frequency component of the absolute velocity of the cooling air jetted out, it becomes smaller by a factor of u ₂ /u ₁ .

That is, as the circumferential velocity component of the absolute velocity of the cooling air jetted into the air gap 20 becomes smaller, the angular velocity becomes smaller and the angular momentum becomes smaller. The ventilation power loss caused by this disappearing in the air gap 20 is greatly reduced. or,
By changing the thickness of the guide cover's wedge-shaped cross section on the side where it is attached to the magnetic poles, the speed of the ejected air can be changed freely, so conditions such as the shape of the duct part on the stator side and the circumferential speed of the rotor can be changed. The optimum ejection speed can be obtained depending on the

In addition, although the above embodiment describes a salient pole rotor, a cylindrical rotor may also be used.
Further, the cooling medium may be a cooling medium other than air, and the same effects as in the above embodiment can be achieved.

As explained above, in this invention, the direction of the cooling medium jetted from the rotor spider side to the air gap side is tilted in the opposite direction to the rotation direction of the rotor, so that the ventilation power loss can be reduced and sufficient efficiency can be obtained. can.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional view showing a conventional salient pole rotor.
Figure 2 is a sectional view taken along the - line in Figure 1;
The figure is a longitudinal sectional view showing a salient pole rotor according to an embodiment of the present invention, FIG. 4 is a sectional view taken along the - line in FIG. 3, and FIG. 5 is a principle diagram for explaining the principle of the invention. be. In the figure, 2 is a rotor spider, 18 is a rotor, and 20 is an air gap. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a rotor of a rotating electric machine having a configuration in which a cooling medium passes between a plurality of magnetic poles and is ejected to an air gap part, a cooling medium is provided on one side of each of the magnetic poles over the entire length in the axial direction without protruding into the air gap surface. A guide cover is provided which extends along the outer periphery in a direction opposite to the rotational direction and is attached to cover between the respective magnetic poles and has a gap from the side surface of the magnetic poles on the opposite side to the attachment side, and the guide cover is made of a non-magnetic material, A rotor for a rotating electric machine, characterized in that the cross section in the direction perpendicular to the shaft is wedge-shaped.