JPS6220779B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an externally ventilated DC machine that is compact and has a large capacity while reducing ventilation resistance loss.

With the exception of small-capacity machines, ventilation in DC machines is overwhelmingly of the external ventilation type, where cooling ventilation is supplied from a separate system, and air is taken in from the side opposite to the commutator of the rotor and exhausted to the commutator side. is typical. At that time, the amount of air required to cool the machine is determined by the capacity of the machine, the temperature rise limit, etc., but the ventilation resistance loss that occurs when the required amount of air flows into the machine is the ventilation resistance inside the machine, that is, It is related to the cross-sectional area and length of the ventilation duct.
Since this ventilation resistance loss and the air volume determine the size of the cooling fan, the ventilation resistance loss when flowing the required air volume should be as small as possible.

However, as machines continue to become smaller, the ratio of in-machine ventilation loss to air volume is inevitably increasing, and as capacity increases, current ventilation methods calculate that in-machine ventilation resistance loss is several hundred mmAq. As a result, a distributed ventilation system was devised to reduce the ventilation resistance inside the aircraft.

This guides all the air taken in from the machine's intake port to the inner periphery of the rotor core, and flows it to the radial outer periphery from the radial duct provided in the rotor core.
The stator is cooled and discharged to the outside of the machine through louvers provided on the commutator side and the anti-commutator side. That is, the waste is distributed and discharged from near the center of the machine to both sides in the axial direction.

In this way, if the cabin air volume is the same,
Compared to unidirectional ventilation, it has the effect of significantly reducing in-machine ventilation resistance loss, but air tends to stagnate near the distribution branch point of the stator, and the cooling effect for the same air volume is greatly reduced on the stator side. In order to obtain the same cooling effect as directional ventilation, the amount of air must be increased, which cancels out the ventilation resistance loss that has been reduced so much that it becomes close to the value of unidirectional ventilation, which is a major drawback.

The present invention takes in a part of the supply air directly from the outer periphery of the stator, guides it near the distribution branch point where air tends to stagnate, and sends it to the commutator side and the anti-commutator side together with the warmed air that comes from the rotor side. The purpose of the present invention is to provide an externally ventilated DC machine that significantly reduces ventilation resistance loss and improves the cooling effect by distributing ventilation.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3. Reference numeral 1 denotes a rotor, which is supported on a bearing stand 3 via a shaft 2. Its iron core 4 is fixed to the rotating shaft 2 via a spider 33 having a ventilation hole 32, and is axially supported by a large number of radial ducts 5. It is divided. 6 is a commutator. A main pole core 9 and a commutator pole core 10 of the stator are attached to an annular frame core 11 through gap 7 and 8 in this rotor 1, and each core 9 and 10 has a main pole coil 12 and Commuting coil 13
is wrapped. Near the center of the frame core 11, a plurality of air guide holes 15 are formed in the radial direction from the space 14 between the main pole and the complementary pole. Frame core 11
Both sides of the frame are supported by frame side plates 16, and a frame cover 18, which is an air guiding member, is provided on the outer periphery of the frame side plate 16 so as to create a ventilation passage 17 between the frame cover 1 and the frame core 11.
A ventilation hole 19 is provided at the bottom of 8. Reference numeral 20 denotes a base to which the bearing stand 3 and the frame side plate 16 are attached, and a pit 21 forming a ventilation passage is bored in the lower inside of the base 20. A blower 22 blows air into the pit 21 from outside. 23,2
4 is a cover with a louver 2 as a ventilation outlet.
5,26. Reference numeral 27 is a partition plate provided between the wall of the pit 21 and the frame side plate 16 to prevent the cooling air inside the pit 21 from escaping directly to the louver 25. 28 and 34 are partition plates attached to the cover 24 or the frame side plate 16, respectively, to guide cooling air into the rotor 1. Reference numeral 29 is a damper provided in the ventilation hole 19, and is used to adjust the amount of cooling air that enters the air guide hole 15. Reference numeral 30 denotes a distribution branch point that distributes ventilation to the commutator 6 side and the opposite commutator side in the space 14 between the main pole and the commutator pole on the stator side, and approximately outside the center of the rotor 1.

Next, the operation of this configuration will be explained.

The cooling air supplied to the machine is divided into two types: one that passes through the rotor 1 as shown by the arrow, and the other that does not pass through the rotor 1 and enters the ventilation passage 17 through the ventilation opening 19 of the frame cover 18, and then flows through the frame core 11 of the stator. The air passes through the air guide holes 15 from the outer circumferential side and is divided into the main pole and the air introduced into the space 14 between the complementary poles. Therefore, the amount of air passing through the rotor 1 side is reduced, and the ventilation resistance loss is reduced. On the other hand, in the case where the air guide hole 15 is not provided, the space 14 between the main pole and the complementary pole near the distribution branch point 30 where air is sent through the air guide hole 15 is the gap 7 between the rotor 1 and the main pole iron core 9, and The wind speed is much lower than that in the gap 8 between the commutating pole iron cores 10, and therefore the ventilation resistance loss in this space 14 is small. Therefore, even if the air flow in this space 14 is increased by providing the air guide hole 15, since it is a bypass, it will not lead to an increase in the overall ventilation resistance loss. Compared to this, it decreases considerably. The distributed wind is released from the louvers 25 and 26 on the commutator side and the anti-commutator side.

In terms of the cold pole effect, the rotor part shows no decrease in the cold pole effect even if the air volume is reduced to some extent, whereas the temperature of the main pole coil 12 and the commuting pole coil 13 decreases due to the space 14 between them. Since the air is ventilated with cold supply air in a manner that wipes out the air that tends to stagnate in the past, a significant reduction can be achieved with a small increase in air volume, and overall, the cooling effect is greatly increased. Note that temperature adjustment and temperature balance adjustment can be easily performed by adjusting the damper 29 of the bypass circuit.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings.
Of course, various modifications can be made without changing the gist of the invention, such as by attaching a duct to 5 to guide cooling air and changing the structure of the air guide member.

As explained above, according to the present invention, a portion of the supply air is guided to the space 14 between the main pole and the subpole of the stator where air tends to accumulate without passing through the rotor, thereby performing distributed ventilation. As a result, the in-machine ventilation resistance loss can be reduced, the cooling effect on the stator side can be improved, the blower 22 and the machine can be downsized, and a DC machine with a larger capacity can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing an embodiment of the externally ventilated DC machine of the present invention, FIG. 2 is an enlarged sectional view of the rotor section, and FIG. 3 is a view taken along the - line in FIG. 1. FIG. 1... Rotor, 4... Rotor core, 5... Radial duct, 6... Commutator, 11... Frame core, 14... Space between main pole and commutator pole, 15... Air guide hole , 16... Frame side plate, 17... Ventilation duct,
18... Frame cover, 19, 32... Ventilation port, 22... Blower, 23, 24... Cover, 2
5, 26...louver, 27, 28, 34...partition plate, 30...distribution branch point, 33...spider.

Claims (1)

[Claims] 1 A rotor equipped with an iron core having a radial duct and a spider having ventilation holes, a circular ring surrounding the outer periphery of this rotor, holding a plurality of field poles inside, and radial air guide holes between the field poles. a frame core having a frame core, a frame cover forming a ventilation passage around the outer periphery of the frame core and having a ventilation hole on the outside;
a cover that forms a machine outer cover together with the frame cover and has a ventilation outlet; a partition plate that is attached to this cover and a frame side plate on the side surface of the frame core to guide cooling air to the ventilation opening of the spider;
This externally ventilated DC machine is characterized by comprising a partition plate provided between an outer wall and a frame side plate to guide cooling air to the ventilation opening of the frame cover, and a blower that sends cooling air into the machine.