WO2017085890A1

WO2017085890A1 - Electric blower and electric cleaner

Info

Publication number: WO2017085890A1
Application number: PCT/JP2015/082792
Authority: WO
Inventors: 奈穂安達
Original assignee: 三菱電機株式会社
Priority date: 2015-11-20
Filing date: 2015-11-20
Publication date: 2017-05-26
Also published as: TW201719023A; TWI645114B; JPWO2017085890A1; JP6422596B2

Abstract

Provided are a high-efficiency electric blower and an electric cleaner equipped with the same. The electric blower (6) is provided with a centrifugal impeller (11), a fan cover (16), and an electric drive part. The centrifugal impeller (11) includes a disk-shaped hub (23) having a primary surface, an annular shroud (24), and a plurality of moving blades (25). The moving blades (25) are disposed in plurality between the hub (23) and the shroud (24) in the circumferential direction of the shroud (24). The fan cover (16) is disposed outside the shroud (24) in the axial direction of the centrifugal impeller (11) so as to accommodate the centrifugal impeller (11). The outer peripheral diameter of the shroud (24) is greater than the diameter of a circle circumscribing the outermost peripheral portion of the plurality of moving blades (25). A stepped part (16A) is provided in the fan cover (16) at the position facing the outer peripheral portion of the shroud (24). A portion of the outer circumferential portion of the shroud (24) is disposed inside the stepped part (16A).

Description

Electric blower and vacuum cleaner

This invention relates to an electric blower and a vacuum cleaner.

Conventionally, an electric blower used for a vacuum cleaner is known. The electric blower rotates an annular shroud, a hub disposed opposite the shroud, a plurality of circumferentially disposed moving blades between the shroud and the hub, and a shroud, the hub, and the moving blade. A centrifugal impeller. In such an electric blower, for high efficiency, the airflow flowing out from the centrifugal impeller outlet does not flow into the centrifugal impeller inlet again in the gap between the centrifugal impeller inlet and the fan cover containing the centrifugal impeller. Some have leakage prevention means (see, for example, FIG. 1 to FIG. 3 in JP 2013-60839 A).

JP 2013-60839 A

Generally, a seal member that does not hinder the rotation of the centrifugal impeller is used as the leakage preventing means provided in the gap between the centrifugal impeller inlet and the fan cover. Therefore, when the centrifugal impeller rotates, the shroud and the seal member are rubbed and the seal member is worn. As a result, the leakage preventing effect of the seal member is reduced. When the leakage prevention effect is lowered, the circulation flow in which the airflow flowing out from the centrifugal impeller outlet re-inflows from the centrifugal impeller inlet increases. When such a circulating flow increases, there is a problem that the load applied to the moving blade increases and the efficiency decreases.

The present invention has been made to solve the above-described problems, and an object of the present invention is to reflow the airflow flowing out from the centrifugal impeller outlet into the centrifugal impeller inlet even after long-term operation. An object is to obtain a highly efficient electric blower and a vacuum cleaner equipped with the electric blower by suppressing the circulation flow.

The electric blower according to the present invention includes a centrifugal impeller, a fan cover, and an electric part. The centrifugal impeller includes a disk-shaped hub having a main surface, an annular shroud, and a plurality of moving blades. The hub, the shroud, and the plurality of blades are connected to each other. The shroud faces the main surface of the hub. A plurality of rotor blades are provided in the circumferential direction of the shroud between the hub and the shroud. The bucket is connected to a hub and a shroud. The fan cover is installed outside the shroud in the axial direction of the centrifugal impeller so as to include the centrifugal impeller. The electric part rotates the centrifugal impeller. The outer diameter of the shroud is larger than the diameter of a circle circumscribing the outermost periphery of the plurality of blades. The fan cover is provided with a step portion at a position facing the outer periphery of the shroud. A part of the outer periphery of the shroud is disposed inside the stepped portion.

The electric blower of the present invention can reduce the gap between the shroud and the fan cover at the step portion of the fan cover. For this reason, since there is no contact part in the said level | step-difference part, there is no fear of the function fall by abrasion, and the flow of the air which re-enters a centrifugal impeller can be reduced by making the said clearance gap small. As a result, a highly efficient electric blower having excellent durability can be realized. Furthermore, a highly efficient electric vacuum cleaner can be obtained by mounting this electric blower.

It is a schematic diagram of the vacuum cleaner which shows embodiment of this invention. It is sectional drawing of the perpendicular direction of the electric blower in embodiment of this invention. It is sectional drawing of the perpendicular direction which shows a part of electric blower in embodiment of this invention. It is a vertical sectional view showing a part of the downstream side of the centrifugal impeller 11 in a modification of the embodiment of the present invention. It is a vertical cross section which shows a part of electric blower in the modification of embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

<Configuration of electric vacuum cleaner according to this embodiment>
FIG. 1 is a schematic view of a vacuum cleaner according to an embodiment of the present invention. In FIG. 1, the present vacuum cleaner includes a vacuum cleaner body 1, a suction tool 4, a dust collecting unit 5, an electric blower 6, and a discharge port 7. The suction tool 4 is connected to the main body 1 of the vacuum cleaner by a hose 2 and an extension pipe 3 as a conduit, and sucks air in a portion to be cleaned. The hose 2 is connected to the main body 1 of the vacuum cleaner. The extension pipe 3 is connected to the tip end side of the hose 2. The suction tool 4 is connected to the tip of the extension pipe 3. The dust collection unit 5 is provided inside the vacuum cleaner main body 1, communicates with the suction tool 4, and stores sucked air dust. The electric blower 6 is provided inside the vacuum cleaner main body 1 and sucks air from the suction tool 4 to the dust collecting unit 5. The electric blower 6 is an electric blower according to an embodiment of the present invention described later. The discharge port 7 is provided outside the vacuum cleaner main body 1 and discharges the air after being collected by the dust collecting unit 5 to the outside of the vacuum cleaner main body 1. The discharge port 7 is provided in the back of the vacuum cleaner main body 1 as shown in FIG.

In the side part of the vacuum cleaner body 1, rear wheels 8 are arranged on the rear side in the traveling direction. A front wheel (not shown) is provided on the lower side of the vacuum cleaner body 1 on the front side in the traveling direction.

<Configuration of electric blower according to this embodiment>
FIG. 2 is a vertical sectional view of the electric blower according to the embodiment of the present invention. In FIG. 2, the arrows indicate the air flow. FIG. 3 is a vertical sectional view showing a part of the electric blower shown in FIG. 2.

2 and 3, the electric blower 6 according to the embodiment of the present invention includes a centrifugal impeller 11, a fan cover 16, and an electric unit 9. The centrifugal impeller 11 includes a disk-shaped hub 23 having a main surface, an annular shroud 24, and a plurality of moving blades 25. The hub 23, the shroud 24, and the plurality of blades 25 are connected to each other. The shroud 24 faces the main surface of the hub 23. A plurality of moving blades 25 are provided in the circumferential direction of the shroud 24 between the hub 23 and the shroud 24. The moving blade 25 is connected to the hub 23 and the shroud 24. The fan cover 16 is installed outside the shroud 24 in the axial direction of the centrifugal impeller 11 so as to include the centrifugal impeller 11. The electric unit 9 rotates the centrifugal impeller 11. The electric unit 9 is disposed inside the electric blower 6. The motorized part 9 includes a shaft 10. The centrifugal impeller 11 is fixed to the shaft 10. The electric part 9 rotates the centrifugal impeller 11 by rotating the shaft 10. The electric motor 9 is an electric motor such as a motor.

A diffuser 15 is disposed between the electric unit 9 and the centrifugal impeller 11. The diffuser 15 includes a plurality of stationary blades 12, a plurality of return stationary blades 13, and a main plate 14. The plurality of stationary blades 12 are disposed on the outer peripheral side of the centrifugal impeller 11. The return vane 13 is disposed so as to be adjacent to the vane 12 in the axial direction that is the extending direction of the shaft 10. The main plate 14 is located between the stationary blade 12 and the return stationary blade 13, and connects the stationary blade 12 and the returning stationary blade 13.

The fan cover 16 is provided on the top of the centrifugal impeller 11 as described above. The fan cover 16 includes the centrifugal impeller 11 and the stationary blades 12 of the diffuser 15. The outer diameter of the fan cover 16 is larger than the outer diameter of the stationary blade 12. A bell mouth 18 is provided at the center of the fan cover 16 at a position facing the suction port 17 of the centrifugal impeller 11. A gap 21 is provided between the fan cover 16 and the diffuser 15 and serves as a gas flow path from the stationary blade 12 to the returning stationary blade 13 on the outer peripheral side of the stationary blade 12.

A bracket 19 that is connected to the fan cover 16 and encloses the return vane 13 is disposed on the side surface of the electric blower 6. In addition, a motor frame 20 that is connected to the bracket 19 and encloses the electric unit 9 is provided on a side surface of the electric blower 6. The motor frame 20 is provided with several discharge holes 22 through which the air that has passed through the centrifugal impeller 11, the diffuser 15, and the electric motor 9 is discharged.

The outer diameter of the shroud 24 is larger than the diameter of a circle circumscribing the outermost periphery of the plurality of rotor blades 25. The fan cover 16 is provided with a stepped portion 16 A at a position facing the outer periphery of the shroud 24. A part of the outer periphery of the shroud 24 is disposed inside the stepped portion 16A. In the step portion 16 A, the step start position on the inner peripheral side is installed closer to the inner peripheral side than the outer peripheral diameter of the shroud 24. Further, the inner peripheral surface of the step portion 16 A is provided substantially parallel to the surface of the outer peripheral portion of the shroud 24.

From another point of view, in the electric blower 6 shown in FIGS. 2 and 3, the outer diameter of the shroud 24 is larger than the outer diameter of the trailing edges of the plurality of moving blades 25. The axial height at the outer periphery of the shroud 24 is higher than the axial height of the trailing edge of the rotor blade 25. The fan cover 16 is provided with a step 16A that shortens the axial distance between the fan cover 16 and the centrifugal impeller 11. The step portion 16 A is installed on the inner peripheral side of the outer periphery of the shroud 24. A part of the outer periphery of the shroud 24 extends to a position adjacent to the inner wall of the fan cover 16 in the step portion 16A. Here, the distance between the inner surface of the stepped portion 16A and the outer peripheral portion of the shroud 24 may be, for example, not less than 0.3 mm and not more than 0.6 mm.

In the electric blower 6, the outer periphery of the shroud 24 extends in the radial direction perpendicular to the axial direction. The outer periphery of the shroud 24 extends from the outer periphery of the rotor blade 25 toward the outer periphery. The fan cover 16 is provided such that the axial height from the hub 23 with respect to the outer peripheral side of the stepped portion 16 A substantially matches the axial height from the hub 23 with respect to the outer peripheral portion of the shroud 24. Here, the axial height from the hub 23 on the outer peripheral side of the stepped portion 16A of the fan cover 16 is from the surface of the hub 23 to the surface on the hub 23 side in the outer peripheral portion of the stepped portion 16A of the fan cover 16. The distance in the axial direction which is the direction along the shaft 10 is said. The axial height from the hub 23 with respect to the outer peripheral portion of the shroud 24 refers to the distance in the axial direction from the surface of the hub 23 to the surface on the hub 23 side in the outer peripheral portion of the shroud 24. And said two axial height substantially corresponds means the case where the difference of the value of an axial height is 1 mm or less.

In the electric blower 6, the axial height from the hub 23 on the outer peripheral portion of the shroud 24 is higher than the axial height from the hub 23 on the outer periphery of the moving blade 25. Here, the axial height from the hub 23 on the outer periphery of the rotor blade 25 refers to the distance in the axial direction from the surface of the hub 23 to the upper end of the outer periphery of the rotor blade 25.

<Effects of electric blower>
2 and 3, since a part of the outer periphery of the shroud 24 is disposed inside the stepped portion 16A of the fan cover 16, the shroud 24 and the fan cover 16 at the stepped portion 16A are arranged. The gap between the two can be reduced. For this reason, the circulation flow in which the airflow which flowed out from the centrifugal impeller 11 exit re-enters the centrifugal impeller 11 entrance is suppressed. And efficiency improves because the load concerning the moving blade 25 reduces. Furthermore, since there is no contact portion in the stepped portion 16A, there is no risk of functional deterioration due to wear. As a result, the electric blower 6 having excellent durability and high efficiency can be realized. Furthermore, by mounting this electric blower 6, a highly efficient vacuum cleaner can be obtained.

In addition, since the axial height from the hub 23 on the outer peripheral portion of the shroud 24 is higher than the axial height from the hub 23 on the outer periphery of the moving blade 25, the flow from the outlet of the moving blade 25 is expanded. It flows into the stationary blade 12 along 24 walls. For this reason, the velocity distribution of the airflow in the axial direction at the inlet of the stationary blade 12 becomes uniform. That is, the gas flow biased toward the hub 23 is returned to the shroud 24 and the velocity distribution becomes uniform. As a result, the collision loss at the leading edge of the stationary blade 12 is reduced. Furthermore, the static pressure rise in the stationary blade 12 is increased, and the electric blower 6 with high static pressure and high efficiency can be realized.

Further, the stepped portion 16 A provided in the fan cover 16 has an inner peripheral side step start position located on the inner peripheral side with respect to the outer peripheral diameter of the shroud 24. Further, the inner peripheral surface of the step portion 16 A is provided substantially parallel to the outer peripheral portion of the shroud 24. For this reason, it is possible to form a lap allowance that maintains a narrow gap between the shroud 24 and the fan cover 16. Here, the width of the lapping margin is the width of the portion where the narrow gap is maintained in the radial direction as viewed from the shaft 10. The width of the lapping margin can be set to 2 mm or more, for example. By forming such a lapping allowance, the circulation flow of the centrifugal impeller 11 can be further reduced. Therefore, the load applied to the moving blade 25 can be reduced.

Further, since the outer periphery of the shroud 24 is provided with an extending portion in the horizontal direction, the flow of air discharged from the centrifugal impeller 11 is smoothly guided to the stationary blade 12 in the horizontal direction. For this reason, the ventilation resistance in the electric blower 6 can be reduced.

Further, since the axial height on the outer peripheral side of the stepped portion 16A of the fan cover 16 is provided so as to substantially coincide with the axial height of the outer peripheral portion of the shroud 24, the flow of air discharged from the centrifugal impeller 11 Is guided to the stationary blade 12 without colliding with the fan cover 16. For this reason, the ventilation resistance in the electric blower 6 can be further reduced.

<Operation and effect of vacuum cleaner>
Next, the operation of the vacuum cleaner will be described.

In the vacuum cleaner configured as described above, when electric power is supplied to the motor unit 9, the shaft 10 rotates. As the shaft 10 rotates, the centrifugal impeller 11 attached to the shaft 10 rotates and sucks air from the suction port 17. Thereby, the air on the surface to be cleaned is sucked into the vacuum cleaner body 1 through the hose 2, the extension pipe 3, and the suction tool 4 connected to the vacuum cleaner body 1. The air sucked into the electric vacuum cleaner main body 1 is collected in the dust collecting unit 5. Thereafter, the air discharged from the dust collecting unit 5 passes through the bell mouth 18 of the electric blower 6 and is sucked from the suction port 17 of the centrifugal impeller 11. The air sucked into the centrifugal impeller 11 is increased in pressure and accelerated by the centrifugal impeller 11, and travels radially outward while turning. Part of the air discharged from the centrifugal impeller 11 becomes a circulating flow that re-enters the suction port of the centrifugal impeller 11 through the gap between the shroud 24 and the fan cover 16. On the other hand, most of the air discharged from the centrifugal impeller 11 is decelerated and boosted between the vanes of the stationary blade 12 of the diffuser 15. Thereafter, the air passes through the gap 21 between the diffuser 15 and the fan cover 16. Further, the air is guided to the electric unit 9 side by the return stationary blade 13 to cool the electric unit 9. Thereafter, air is discharged from the discharge hole 22 provided in the motor frame 20 to the outside of the electric blower. And air is discharged | emitted from the discharge port 7 provided in the vacuum cleaner main body 1 to the outer side of the vacuum cleaner main body 1. FIG.

In the electric vacuum cleaner described above, the outer diameter of the shroud 24 in the electric blower 6 is larger than the outer diameter of the trailing edge of the rotor blade 25. Further, the axial height at the outer peripheral portion of the shroud 24 is higher than the axial height of the trailing edge (outer main side) of the rotor blade 25. The fan cover 16 is provided with a step portion 16A that shortens the axial distance between the fan cover 16 and the shroud 24. Since the electric blower 6 having such a configuration is used, after the air is discharged from the centrifugal impeller 11, the amount of air re-entering the centrifugal impeller 11 through the gap between the shroud 24 and the fan cover 16 is reduced. Can be reduced. For this reason, the increase in the load to the moving blade 25 by the air which re-inflows can be suppressed. As a result, a highly efficient electric blower and vacuum cleaner can be obtained. Moreover, in the electric blower 6 having the above-described configuration, the air flow discharged from the centrifugal impeller 11 easily flows into the fan cover 16 side of the stationary blade 12. For this reason, since it becomes easy to decelerate and pressurize in the stationary blade 12, a vacuum cleaner provided with a high static pressure and a highly efficient electric blower can be obtained.

<Configuration and operation effect of modified example of electric blower>
FIG. 4 is a vertical cross-sectional view of the rotor blade 25 in a modification of the embodiment of the present invention. FIG. 5 is a vertical cross-sectional view showing a part of an electric blower according to a modification of the embodiment of the present invention. The electric blower shown in FIGS. 4 and 5 basically has the same configuration as the electric blower shown in FIGS. 2 and 3, but the shape of the outer peripheral portion of the shroud 24 is different. Specifically, in the electric blower, the outer peripheral portion of the shroud 24 includes an extending portion 31 that is located inside the stepped portion 32 and extends toward the fan cover.

By providing such a configuration, the electric blower shown in FIGS. 4 and 5 can obtain the same effects as the electric blower shown in FIGS. Furthermore, since the extending portion 31 is provided toward the fan cover 16 at the outer peripheral portion of the shroud 24, the flow resistance in the gap between the shroud 24 and the stepped portion 32 of the fan cover 16 can be increased. For this reason, the leakage flow which passes the said clearance gap can further be reduced. As a result, the load on the rotor blade 25 can be reduced.

As described above, the electric blower according to the embodiment of the present invention does not prevent the leakage flow flowing through the gap between the shroud 24 and the fan cover 16 by using the seal member, but the shape of the shroud 24 and the fan cover 16 Suppressed using the positional relationship. For this reason, the fall of the leak prevention effect by aged deterioration is suppressed, and performance can be maintained over a long period of time.

The electric blower as described above is not limited to a household or commercial vacuum cleaner, but can be applied to any device using an electric blower such as a hand dryer. As a result, a highly efficient and long-life device can be realized.

Although the embodiments of the present invention have been described above, the above-described embodiments can be variously modified. The scope of the present invention is not limited to the above-described embodiment. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

The present invention can obtain a high-efficiency device even if it can be advantageously applied to a device using an electric blower, such as a household or commercial vacuum cleaner or a hand dryer.

1 vacuum cleaner body, 2 hose, 3 extension pipe, 4 suction tool, 5 dust collecting part, 6 electric blower, 7 outlet, 8 rear wheel, 9 electric part, 10 shaft, 11 centrifugal impeller, 12 stationary blade, 13 return vane, 14 main plate, 15 diffuser, 16 fan cover, 16A, 32 stepped portion, 17 suction port, 18 bell mouth, 19 bracket, 20 motor frame, 21 clearance, 22 discharge hole, 23 hub, 24 shroud, 25 Rotor blade, 31 extension part.

Claims

A centrifugal impeller including a disk-shaped hub having a main surface, an annular shroud, and a plurality of blades connected to each other;
The shroud faces the main surface;
A plurality of the blades are provided in a circumferential direction of the shroud between the hub and the shroud, and are connected to the hub and the shroud.
A fan cover installed outside the shroud in the axial direction of the centrifugal impeller so as to contain the centrifugal impeller;
An electric part for rotating the centrifugal impeller,
The outer diameter of the shroud is larger than the diameter of a circle circumscribing the outermost periphery of the plurality of blades,
The fan cover is provided with a stepped portion at a position facing the outer periphery of the shroud,
An electric blower in which a part of the outer peripheral portion of the shroud is disposed inside the stepped portion.
2. The electric blower according to claim 1, wherein the stepped portion is disposed closer to the inner periphery than the outer periphery of the shroud and is provided along the outer periphery of the shroud.
The electric blower according to claim 1 or 2, wherein the outer peripheral portion of the shroud extends in a radial direction perpendicular to the axial direction.
The fan cover is provided such that an axial height from the hub on the outer peripheral side of the stepped portion coincides with an axial height from the hub of the outer peripheral portion of the shroud. The electric blower according to claim 3.
The electric blower according to any one of claims 1 to 4, wherein the outer peripheral portion of the shroud includes an extending portion that is located inside the stepped portion and extends toward the fan cover.
6. The axial height from the hub of the outer peripheral portion of the shroud is higher than the axial height from the hub of the outer periphery of the moving blade. Electric blower.
The vacuum cleaner body,
A vacuum cleaner connected to the main body of the vacuum cleaner, and a suction tool for sucking air in the portion to be cleaned;
A dust collection unit provided inside the vacuum cleaner body, communicating with the suction tool, and storing dust of sucked air;
The electric blower according to any one of claims 1 to 6, wherein the electric blower is provided inside the electric vacuum cleaner body and sucks air from the suction tool to the dust collecting unit.
A vacuum cleaner provided on the outer side of the main body of the vacuum cleaner, and comprising a discharge port for discharging the air after being collected by the dust collector to the outside of the main body of the vacuum cleaner.