JPH07213018A - Fan apparatus for totally-enclosed fan-cooled rotating machine - Google Patents

Abstract

PURPOSE:To suppress noises by a method wherein two rows of vaned wheels are provided on the outer circunference of a hub in an axial direction, a dual-suction axial fan is provided between the rows of the vaned wheels and a scroll casing which guides exhaust air into a ventilation duct is provided. CONSTITUTION:A fanning apparatus 30 is composed of two rows of backward vanes 23 and 24 which are provided on the outer circumference of a cylindrical hub 22 linked with a rotor shaft 4 so as to face each other in an axial direction, a dual-suction axial fan 21 composed of a disc-type rotary partition 25 provided between the two backward vane rows 23 and 24 and a scroll casing 26 in which the dual-suction axial fan 21 is housed and which guides exhaust air into a ventilation duct 28. Air suction chambers 34 having filters 35 are provided on both sides of the backward vanes 23 and 24. The sucked air 31 made to flow into the fanning apparatus 30 from both sides when the shaft 4 is made to rotate are actuated in a direction having a same angle determined by the angle 0 of the backward vanes 33 and 34 and, further, the courses of the sucked air flows 31 are changed in a radial direction by the rotary partition 25 to be converted into air flows which circle around the hub. As a result, the cooling air flow rate necessary for a radiator can be shared by the two rows of the vaned wheels, so that the outer diameter of the apparatus 30 can be reduced and the produced noises can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided for blowing cooling air to a radiator in a low-noise fully-closed external fan electric motor, a fully-closed external fan-type generator, etc., which requires low noise. It relates to an external fan device.

[0002]

2. Description of the Related Art Noise problems have been emphasized in connection with improvement of living environment, working environment, etc., and accordingly, reduction in noise of rotating electric machines has been demanded. In particular, in a rotating electric machine with a relatively large capacity and a high rotation speed, the rotor, the stator, and the internal fan device, which are the main parts of the rotating electric machine, have a fully closed structure, and mechanical noise and magnetic noise generated in this part are generated. , And ventilation noise are reduced. However, the noise level generated in the external fan device that supplies the external cooling air to the heat exchanger that cools the internal circulating air often exceeds the permissible level of the surrounding environment, and measures for reducing the noise level are required.

FIG. 3 is a sectional view of a main part schematically showing a conventional cooling device for a totally enclosed fan-type rotating electric machine.
A is a stator 2 wound around a stator core 2B, and a shaft 4
The rotor 3 supported by is housed in a fully-closed casing 5 having a panel-type radiator 11 at the top, and a shaft 4 penetrating the casing 5 is rotatable by a bearing device 6. Supported by. Further, in the casing 5, a hub 7 fixed to the shaft 4, an axial fan 8 radially provided on the outer peripheral surface of the hub 7, and air discharged from the axial fan 8 are guided to a stator and a rotor. An inner fan device 10 including an air guide 9 is provided, and the air discharged from the axial fan 8 cools the rotor 3 and the stator 2 and radiates heat in a radiator 11 to lower the temperature.
An internal cooling air flow 12A that recirculates to the suction side of the axial fan 8 is formed again, and for example, the stator winding 2A is configured to be cooled below its allowable temperature.

The external fan device 20 is composed of an axial fan 18 radially protruding from the outer circumference of a hub 17 connected to the end of the shaft 4 of the rotating electric machine, and a scroll casing 19 surrounding the axial fan 18. The scroll casing 19 is the air duct 1
It is connected to the radiator 11 via 6. Further, the air supply chamber 1 having an air filter-15 on the intake side of the axial fan 18
4 is provided, and the external cooling air flow 12B discharged in the direction in which the hub 17 is rotated by the axial fan 18 is a scroll scale.
In the sing 19, it is guided into the blower duct 16 in a state where it gathers into one flow, and is branched and supplied to, for example, a plurality of heat exchange panels of the radiator 11 to perform heat exchange with the internal cooling air flow 12A and to radiate heat. Internal cooling air flow 1 cooled in the vessel 11
2A circulates to the side of the stator 2 and the rotor 3 via the inner fan device 10 to cool the rotating electric machine.

[0005]

In the conventional external fan device 20, since the external cooling air 12B required by the radiator 11 is generated by the axial flow fan 18 consisting of a row of impellers, the discharge air amount thereof is small. Due to this, as the outer diameter of the axial flow fan 18 increases and its peripheral speed increases, the level of noise generated increases in proportion to the increase in peripheral speed, and the noise level in the noise test exceeds the allowable value. There was a problem that it would end up.

Further, there is a problem in that a silencer (not shown) is required in order to keep the noise level below the permissible value, and as a result, the fully-closed fan-type rotating electric machine becomes large in size.
Furthermore, if the outer diameter of the fan is reduced in order to reduce the noise level to below the allowable value, the discharge air volume will be insufficient.Therefore, in order to compensate for this, it is necessary to increase the size of the rotating electrical machine body to reduce the generated loss. , There was a problem of causing economic disadvantage.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fully-closed outer fan type rotating electric machine equipped with a noise reducing outer fan device which can obtain a required discharge air volume without increasing the size of the rotating electric machine.

[0008]

In order to solve the above problems, according to the present invention, a radiator for performing heat exchange between internal cooling air and external cooling air is connected via a ventilation duct,
In the one for supplying external cooling air to the radiator, two rows of impellers are provided on an outer peripheral surface of a hub connected to a rotor shaft so as to face each other at intervals in the axial direction, and the two rows of impellers. A double suction axial flow fan composed of a disk-shaped rotary partition wall provided in the middle of the impeller, and a scroll valve for accommodating the double suction axial flow fan and guiding the discharge air to the blower duct.
Sing shall be provided.

Two rows of impellers of both suction axial fans provided on the outer peripheral surface of the hub so as to be opposed to each other at intervals in the axial direction thereof maintain rearward facing angles symmetrical with respect to the axis of the hub. It shall consist of a pair of rearward facing wing rows that are radially provided. It is assumed that the scroll casing and the ventilation duct define two ventilation paths parallel to each other by a stationary partition wall.

[0010]

In the present invention, two rows of impellers are provided with the outer fan device provided on the outer peripheral surface of the hub connected to the rotor shaft so as to face each other at intervals in the axial direction thereof, and the two rows of impellers. Both suction axial flow fans consisting of a disk-shaped rotary partition wall provided in the middle of the above, and a scroll casing for accommodating the both suction axial flow fans and guiding the discharge air to the blower duct. The discharge air that has passed through both suction axial fans while swirling in the same direction on the surface of the cylindrical hub is urged by the rotary partition wall in the radial direction (direction parallel to the rotary partition wall), and further scroll casing. In the process of swirling inside, the discharge air of a plurality of rotor blades joins and is directed in the direction of the air duct. At this time, the discharge air volume of each of the two rows of axial flow fans is 1 / l of the external cooling air volume required by the radiator.
Since it is possible to reduce the number of noises to 2, the outer diameter of the impeller of the double suction axial flow fan can be made smaller than that of the conventional single suction axial flow fan, and the generated noise is reduced without reducing the discharge air volume accordingly. The function to do is obtained.

Further, a pair of impellers of both suction axial fans provided on the outer peripheral surface of the hub so as to be opposed to each other at intervals in the axial direction thereof maintain rearward-facing angles symmetrical with respect to the axis of the hub. If a pair of rearward wing rows are provided radially in a radial manner, the discharge air volume can be easily secured by increasing the number of blades, so that the function of reducing the outer diameter and reducing the generated noise can be obtained. .

On the other hand, if the scroll casing and the blower duct are defined by the stationary partition walls into two air passages which are parallel to each other, the discharge air amount of each of the pair of impellers is supplied to each half of the radiator. However, it is possible to obtain the function of reducing the deviation of the cooling air flow depending on the position in the radiator.

[0013]

EXAMPLES The present invention will be described below based on examples. FIG. 1 is a sectional view of a main part schematically showing an outer fan device of a fully-closed outer fan type rotary electric machine according to an embodiment of the present invention, and FIG. 2 is a view schematically showing a main part of a double-suction axial fan according to the embodiment. Therefore, the same components as those of the conventional technique are designated by the same reference numerals, and the duplicate description will be omitted. In the figure,
The external cooling air (flow) 12A and the external cooling air (flow) 32 are connected to the radiator 11 that exchanges heat via the air duct 28, and the external cooling air (flow) 32 is supplied to the radiator 11. The outer fan device 30 includes, for example, two rows of impellers, such as rearward wing rows, which are provided on the outer peripheral surface of a cylindrical hub 22 that is shrink-fitted onto the rotor shaft 4 so as to face each other at intervals in the axial direction. 23 and 24, and a double suction axial flow fan 21 composed of a disk-shaped rotary partition wall 25 provided in the middle of the two rearward facing wing rows 23 and 24, and the double suction axial flow fan 21 is housed. It is composed of a scroll casing 26 which guides the discharged air to a blower duct 28. In addition, the scroll casing 26
The inside of the air blow duct 28 is defined by the stationary partition wall 27 provided corresponding to the rotary partition wall 25 into two mutually parallel air flow paths, and the discharge air of each of the rearward blade rows 23, 24 is external cooling air flow 32A, 32B. Is supplied to each half of the radiator 11.

By the way, a pair of rearward facing rows 2 provided on the outer peripheral surface of the hub 22 so as to face each other at intervals in the axial direction thereof.
As shown in FIG. 2, the reference numerals 3 and 24 are composed of a plurality of rearward wing 33 and 34 which are radially symmetrically projecting while maintaining the same rearward angle θ with respect to the axis of the hub 22.
Further, a filter 35 is provided on both sides of the rear wing rows 23, 24.
The intake chamber 34 having the following is provided, and when the shaft 4 is rotated in the direction of the arrow in the figure, the intake air 31 that has flowed in from both sides of the rearward wing rows 23, 24 is determined by the rearward angle θ of the rearward blades 33, 34. Since it is biased in the same angular direction and changes its course in the radial direction by the rotary partition wall 25, it becomes an air flow that swirls around the hub. Therefore, the scroll casing 26
The discharge air of the plurality of rearward-facing blades is combined with each other and directed to the blower duct 28 divided into two chambers, whereby the discharge air of the pair of rearward-facing blades 23, 24 is respectively cooled by the external cooling air flow 32A ,. 32B can be supplied to each half of the radiator 11 to exchange heat with the internal cooling air 12A.

In the external fan device 30 constructed in this way, the amount of air discharged from each of the rearward fan rows 23 and 24 of both suction axial fans 21 is 1/2 of the amount of external cooling air required by the radiator 11. Therefore, the outer diameter of the rear wing rows 23, 24 can be made smaller than that of the conventional single-suction axial flow fan.
In particular, when the rotating speed of the rotating electric machine is high, the reduction of the peripheral speed of the impeller due to the reduction of the outer diameter has a great effect on the reduction of the generated noise level, so that the effect of reducing the generated noise without reducing the discharge air volume is effective. can get.

Further, a pair of impellers of both suction axial fans provided on the outer peripheral surface of the hub so as to be opposed to each other at intervals in the axial direction thereof maintain rearward facing angles symmetrical with respect to the axis of the hub. By forming a pair of rearward-facing blade rows radially projecting, it is possible to easily secure the discharge air volume by increasing the number of blades, and thus it is possible to obtain the effect of reducing the outer diameter and reducing the generated noise. In addition, by defining the inside of the scroll casing and the air duct with two air passages that are parallel to each other by the stationary partition, the discharge air volume of each of the pair of impellers is supplied to each half of the radiator, and It is possible to obtain the effect of reducing the deviation of the cooling air flow depending on the position.

[0017]

As described above, according to the present invention, the outer fan device is composed of the double suction axial flow fan composed of the two rows of impellers and the rotary partition wall facing each other, and the scroll casing.
As a result, the discharge air volume of one impeller can be divided into the cooling air volume required by the radiator by the discharge air volumes of the two rows of impellers, so that the outer diameter of the impeller can be reduced. Since an external fan device with a low generated noise level itself can be obtained without reducing the air volume, in order to cover the reduction of the cooling air volume, or the installation of a silencer required to reduce the leakage of noise in the conventional technology. The problems such as the increase in the size of the rotating electric machine that was required are eliminated, and a fully-enclosed fan-type rotating electric machine that is small and has low noise, especially a fully-closed fan-type rotating electric machine with a high rotation speed, is provided economically advantageously. be able to.

Further, by providing the impeller with two rows of backward-facing blades which are symmetrical with each other, it is possible to provide a fully-closed outer fan type rotating electric machine equipped with an outer fan device which has a large effect of reducing the outer diameter and has a low noise. it can. Furthermore, if the air blow passage is divided into two by the stationary partition wall and the discharge air volume of the two rows of impellers is supplied to each half of the heat radiation, the deviation of the cooling air volume in the radiator can be reduced and the internal cooling air can be reduced. The effect of increasing the heat exchange efficiency with is obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part schematically showing an external fan device of a fully-closed external fan-type rotating electric machine according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a main part of a double-suction axial fan according to an embodiment.

FIG. 3 is a cross-sectional view of a main part schematically showing a cooling structure of a conventional fully-enclosed fan-type rotary electric machine

[Explanation of symbols]

 2 stator 3 rotor 4 shaft 5 casing 6 bearing device 7 hub 8 axial fan 9 air guide 10 inner fan device 11 radiator 12A internal cooling air 12B external cooling air 16 air duct 17 hub 18 axial fan 19 scroll -Looking 20 External fan device 21 Both suction axial flow fan 22 Hub 23 Rearward vane row (impeller) 24 Rearward vane row (impeller) 25 Rotating partition wall 26 Scroll casing 27 Stationary partition wall 28 Air duct 30 External fan device 31 Intake 32 External cooling air flow 34 Intake chamber

Claims (3)

[Claims] 1. A hub, which is connected to a radiator for exchanging heat between internal cooling air and external cooling air via a ventilation duct and supplies external cooling air to the radiator, the hub being connected to a rotor shaft. Double-suction axial flow fan consisting of two rows of impellers provided on the outer peripheral surface of the blades so as to face each other at intervals in the axial direction, and a disc-shaped rotary partition wall provided in the middle of the two rows of impellers. And a scroll casing which accommodates the both suction axial fans and guides the discharge air to the blower duct. 2. The two rows of impellers of both suction axial fans provided on the outer peripheral surface of the hub so as to be opposed to each other at intervals in the axial direction thereof maintain rearward-facing angles symmetrical with respect to the axis of the hub. The outer fan device for a fully-closed outer fan type rotary electric machine according to claim 1, wherein the outer fan device comprises a pair of rearward-facing blade rows that are radially projected. 3. The whole casing according to claim 1, wherein the scroll casing and the air duct define two air passages which are parallel to each other by a stationary partition which surrounds the rotary partition from its outer peripheral side. An external fan device for a closed fan electric rotating machine.