TWI605199B - Electric blower and vacuum cleaner - Google Patents

Description

Electric blower and electric vacuum cleaner

The invention relates to an electric blower and an electric vacuum cleaner.

Conventionally, an electric blower used in an electric vacuum cleaner has been known. The electric blower includes a toroidal shroud, a hub disposed to face the shroud, a plurality of rotating blades disposed in a circumferential direction between the shroud and the hub, and a rotating shroud, The hub and the radial impeller of the rotating blade. In the electric blower, in order to increase the efficiency, the gap between the radial impeller inlet and the fan cover of the inner impeller includes a leak stop means to prevent the airflow from the radial impeller outlet from flowing into the radial direction. The impeller inlet (Japanese Patent Application Publication No. 2013-60839 (Patent Document 1), the first to third drawings, and the Japanese Patent Publication No. 2000-154797).

[Prior patent documents] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-60839

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2000-154797

As shown in Japanese Laid-Open Patent Publication No. 2013-60839, the leak stop means provided in the gap between the radial impeller inlet and the fan cover is used without hindering the diameter. The case of a sealing member that turns to the impeller. In this case, when the radial impeller rotates, the shroud rubs against the sealing member, and the sealing member wears. As a result, the leakage preventing effect of the sealing member is lowered. When the leak stop effect is lowered, the circulation flow from the radial impeller outlet recirculates from the radial impeller inlet to increase. When such a circulating flow is increased, the load acting on the rotating blades is increased, which has a problem of reduced efficiency.

Further, as shown in the Japanese Patent Laid-Open Publication No. 2000-154797, the sealing structure has a structure in which a groove is provided on the inner peripheral side end surface of the shroud, and an inner circumferential side end portion of the fan cover is fitted to the groove. Happening. However, even with this configuration, the airflow flowing from the sealing structure to the radial impeller inlet is mixed with the main flow of the air taken in from the inlet of the extended impeller. When this reflowing airflow is mixed with the main flow at the radial impeller inlet, the collision loss at the leading edge of the rotating blade is increased, and there is still a problem of reduced efficiency.

The present invention has been made in order to solve the problems as described above, and an object of the present invention is to provide a highly efficient electric blower and an electric vacuum cleaner equipped with the electric blower.

The electric blower of the present invention includes a radial impeller, a fan cover, and a motorized portion. The radial impeller includes a disk-shaped hub having a surface, a circular shroud, and a plurality of rotating blades. The shroud faces the surface of the hub. The rotating blade is disposed between the hub and the shroud in a plurality of sheets in the circumferential direction of the shroud. The rotating blade is coupled to the hub and the shroud. The fan cover is disposed outside the shroud in the direction of the radial direction of the radial impeller so as to enclose the radial impeller. The fan cover has an opening portion having a center point on the rotating shaft. The electric part rotates the radial impeller. The rotating blade includes a first portion located inside the periphery of the opening.

In the electric blower of the present invention, the inner wall of the opening of the fan cover is located on the outer peripheral side (downstream side) of the first portion on the upstream side in the flow direction of the air. The gap between the inner wall of the opening of the fan cover and the shroud is a flow path of air (circulating flow) that flows in from the radial impeller outlet to the radial impeller inlet. Therefore, the circulating flow flows into the radial impeller from the downstream side of the first portion of the rotating blade. Therefore, it is possible to suppress the occurrence of a problem that the circulating flow flows into the upstream side of the first portion of the rotating blade, and the main flow and the circulating flow are mixed to generate a complicated flow of air, and as a result, the load acting on the rotating blade is increased. And the efficiency is reduced. As a result, a highly efficient electric blower can be realized. Further, by mounting the electric blower, a highly efficient electric vacuum cleaner can be obtained.

1‧‧‧ electric vacuum cleaner body

2‧‧‧Hose

3‧‧‧Extension tube

4‧‧‧Inhalation parts

5‧‧‧Dust collection department

6‧‧‧Electric blower

7‧‧‧Export

8‧‧‧ rear wheel

9‧‧‧Electric Department

10‧‧‧Axis

11‧‧‧ Radial impeller

12‧‧‧Fixed blades

13‧‧‧Return fixed blades

14‧‧‧ motherboard

15‧‧‧Diffuser

16‧‧‧Fan cover

17‧‧‧Inhalation

18‧‧‧ bell mouth

18A‧‧‧Bottom

19‧‧‧ bracket

20‧‧‧ motor frame

21‧‧‧ gap

22‧‧‧Exhaust hole

23‧‧·wheels

24‧‧‧ Shield

25‧‧‧Rotating blades

26‧‧‧ sloping section

26A~26C‧‧‧Parts

34‧‧‧Part 2

35‧‧‧Slots

36‧‧‧Part 1

36A‧‧‧ end face

36B‧‧‧ top surface

41, 42‧‧‧ arrows

Fig. 1 is a schematic view showing an electric vacuum cleaner according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view showing the vertical direction of the electric vacuum cleaner according to the embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view showing a portion of the electric vacuum cleaner according to the embodiment of the present invention in the vertical direction.

Fig. 4 is a perspective view showing a radial impeller according to an embodiment of the present invention.

Fig. 5 is a schematic cross-sectional view showing a vertical direction of a part of a rotor blade of a radial impeller according to an embodiment of the present invention.

Fig. 6 is a schematic cross-sectional view showing a portion of a modified example of the rotary vane shown in Fig. 5 in the vertical direction.

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

<Configuration of Electric Vacuum Cleaner of the Present Embodiment>

Fig. 1 is a schematic view showing an electric vacuum cleaner according to an embodiment of the present invention. In Fig. 1, the electric vacuum cleaner includes a suction member 4, a dust collecting portion 5, an electric blower 6, and a discharge port 7. The suction member 4 is connected to the vacuum cleaner body 1 by a hose 2 and a pipe 3 as a pipe, and sucks the air of the portion to be cleaned. The hose 2 is connected to the vacuum cleaner body 1. The extension pipe 3 is connected to the front end side of the hose 2. The suction member 4 is connected to the front end portion of the extension pipe 3.

The dust collecting portion 5 is provided inside the vacuum cleaner body 1, and communicates with the suction member 4 to accommodate the dust of the sucked air. The electric blower 6 is provided inside the vacuum cleaner body 1 and takes in air from the suction tool 4 to the dust collecting portion 5. The electric blower 6 is an electric blower according to an embodiment of the present invention to be described later. The discharge port 7 is provided outside the vacuum cleaner body 1, and discharges the air collected by the dust collecting portion 5 to the outside of the vacuum cleaner body 1. The discharge port 7 is provided at the rear of the vacuum cleaner body 1 as shown in Fig. 1 .

On the side portion of the vacuum cleaner body 1, the rear wheel 8 is disposed on the rear side in the traveling direction. In the lower portion of the vacuum cleaner body 1, a front wheel (not shown) is disposed on the front side in the traveling direction.

<Configuration of Electric Air Blower of the Present Embodiment>

Fig. 2 is a schematic cross-sectional view showing the vertical direction of the electric vacuum cleaner according to the embodiment of the present invention. In Figure 2, the arrows indicate the flow of air. Figure 3 A schematic cross-sectional view of a portion of the electric vacuum cleaner shown in Fig. 2 in the vertical direction. Fig. 4 is a perspective view showing a radial impeller constituting the electric vacuum cleaner shown in Fig. 2. Fig. 5 is a schematic cross-sectional view showing a vertical direction of a part of a rotor blade of a radial impeller according to an embodiment of the present invention.

As shown in FIGS. 2 to 5, the electric blower 6 according to the embodiment of the present invention includes a radial impeller 11, a fan cover 16, and a motor unit 9. The radial impeller 11 includes a disk-shaped hub 23 having a surface, a toroidal shroud 24, and a plurality of rotating blades 25. The shroud 24 faces the surface of the hub 23. The rotating blade 25 is provided between the hub 23 and the shroud 24 in a plurality of sheets in the circumferential direction of the shroud 24. The rotor blade 25 is coupled to the hub 23 and the shroud 24. The fan cover 16 is disposed outside the shroud 24 in the direction of the rotation axis of the radial impeller 11 so as to enclose the radial impeller 11 . The motor unit 9 rotates the radial impeller 11 . The motor unit 9 is disposed inside the electric blower 6 . The motor unit 9 includes a shaft 10 . The radial impeller 11 is fixed to a shaft 10. The motor unit 9 rotationally drives the radial impeller 11 by rotating the shaft 10. The motor unit 9 is, for example, an electric motor such as a motor.

A diffuser 15 is provided between the motor unit 9 and the radial impeller 11 . The diffuser 15 includes a plurality of fixed blades 12, a plurality of returning fixed blades 13, and a main plate 14. The plurality of fixed blades 12 are disposed on the outer peripheral side of the radial impeller 11 . The return fixed blade 13 is disposed adjacent to the stationary blade 12 in the direction of the rotation axis of the extending direction of the shaft 10. The main plate 14 is located between the fixed vane 12 and the return fixed vane 13 and connects the fixed vane 12 and the return fixed vane 13.

At the upper portion of the radial impeller 11, a fan cover 16 is provided as described above. The fan cover 16 houses a radial impeller 11 and a stationary vane 12 of the diffuser 15. The outer diameter of the fan cover 16 is larger than the outer diameter of the stationary blade 12. In the center portion of the fan cover 16, a bell mouth 18 having an opening portion having a center point on the rotating shaft of the radial impeller 11 is formed. Here, the center point of the bell mouth 18 is a circular shape of the outer periphery of the bell mouth 18, and is a center point of a circle formed by the outer circumference. Further, in the case where the planar shape of the outer periphery of the bell-shaped opening 18 is a shape other than a circular shape (for example, a polygonal shape), the center point of the bell-shaped opening 18 may be a center of gravity of a planar shape. Further, there is a center point on the rotating shaft, which means not only the case where the rotating shaft overlaps with the center point, but also the case where the center point is contained in a cylindrical region having a radius of 5 mm centered on the rotating shaft. Further, from the viewpoint of the difference, the bell mouth 18 is provided at a position facing the suction port 17 of the radial impeller 11. Further, from the viewpoint of dissimilarity, a bell mouth 18 having a center point on the rotating shaft of the radial impeller 11 is formed in the fan cover 16. The gap 21 is provided between the fan cover 16 and the diffuser 15, and this gap 21 serves as a flow path for the gas on the side of the fixed vane 13 from the fixed vane 12 to the outer peripheral side of the fixed vane 12.

The rotor blade 25 of the radial impeller 11 has a first portion 36 located inside the bell mouth 18 as shown in FIG. The first portion 36 has an end face 36A that faces the inner wall of the bell mouth 18 of the fan cover 16. In the shroud 24, the second portion 34 on the side of the rotating shaft is disposed to face the end surface 36A of the first portion 36. The second portion 34 is formed to extend in the direction of the rotation axis indicated by the one-dot chain line at the right end of the third figure. In the shroud 24, the second portion 34 has an annular planar shape as shown in Fig. 4. The inner wall of the bell mouth 18 is located between the end face 36A and the second portion 34. Further, from the viewpoint of the difference, the groove portion 35 is constituted by a region where the end surface 36A of the first portion 36 of the rotor blade 25 and the second portion 34 of the shroud 24 are sandwiched. The inner wall of the bell mouth 18 is located in the groove portion 35 inside. The inner wall of the bell mouth 18 extends along the second portion 34 of the shroud 24. Further, the inner wall of the bell mouth 18 is an end portion on the inner peripheral side of the fan cover 16. The inner wall of the bell mouth 18 extends along the end face 36A of the first portion 36. The position of the top surface 36B of the first portion 36 is disposed at a position farther than the lower end 18A of the inner wall of the bell mouth 18 when viewed from the hub 23. That is, the first portion 36 of the rotor blade 25 is located inside the outer peripheral edge of the bell mouth 18 of the fan cover 16, and extends above the lower end of the wall portion of the bell mouth 18.

As shown in FIGS. 4 and 5, the first portion 36 includes an inclined portion 26 that is inclined only by the inclination angle θ with respect to the rotation direction R of the rotor blade 25 in the rotation axis direction. Here, the inclination angle θ means an angle between the direction of the rotation axis of the radial impeller 11 and the line segment passing through the central portion in the thickness direction of the inclined portion 26. Further, the dotted arrow R in Fig. 4 indicates the rotational direction R of the rotary vane 25.

A bracket 19 that is coupled to the fan cover 16 and that wraps around the fixed blade 13 is disposed on the side surface of the electric blower 6. Further, a motor frame 20 that is coupled to the bracket 19 and that houses the motor unit 9 is provided on the side surface of the electric blower 6. In the motor frame 20, a radial impeller 11, a diffuser 15, and a discharge hole 22 for discharging air passing through the motor portion 9 are provided at a plurality of places.

<The effect of the electric blower>

According to the configuration shown in Figs. 2 to 5, the inner wall of the bell mouth 18 as the opening portion of the fan cover 16 is located on the outer periphery of the first portion 36 on the upstream side of the rotor blade 25 in the flow direction of the air. Side (downstream side). The gap between the inner wall of the bell mouth 18 and the second portion 34 of the shroud 24 is as shown by arrow 41 in Fig. 3, and is an air that flows in from the radial impeller outlet to the radial impeller inlet (circulating flow). The flow path. Therefore, the circulating flow system is the first from the ratio of the rotating blades 25 The downstream side of portion 36 flows into the radial impeller. Therefore, it is possible to prevent the occurrence of a phenomenon in which the circulation flow flows into the upstream side of the first portion 36 of the rotor blade 25, and the circulation flow is mixed with the main flow as indicated by the arrow 42 in Fig. 3, which is complicated. The flow of air. Therefore, the collision loss at the leading edge (the edge portion of the first portion 36) of the rotor blade 25 can be reduced as compared with the case where such complicated air flow occurs on the upstream side of the rotor blade 25. As a result, the load acting on the rotating blade 25 can be reduced, and the highly efficient electric blower 6 can be realized. Further, by mounting the electric blower 6, a highly efficient electric vacuum cleaner can be obtained.

Further, in the above-described electric blower 6, the first portion 36 has an end surface 36A that faces the inner wall of the bell mouth 18 of the fan cover 16. In the shroud 24, the second portion 34 on the side of the rotating shaft is disposed to face the end surface 36A of the first portion 36. The inner wall of the bell mouth 18 is located between the end face 36A and the second portion 34. With such a configuration, the path of the circulating flow into the radial impeller can be made as a narrow region between the second portion 34 of the shroud 24 and the inner wall of the bell mouth 18 as indicated by arrow 41 in FIG. . Therefore, by setting the distance between the second portion 34 and the inner wall of the bell mouth 18 to be sufficiently narrow, the inflow amount of the circulation flow can be reduced. For example, the distance can be set to 0.1 mm or less and 0.3 mm or less. In this way, the load acting on the rotating blade 25 can be surely reduced.

Further, in the above-described electric blower 6, the inner wall of the bell mouth 18 extends along the second portion 34 of the shroud 24. In this case, since the flow resistance of the gap between the inner wall of the bell mouth 18 and the second portion 34 can be increased, the amount of inflow of the circulating flow from the gap can be effectively reduced. For example, as shown in Fig. 3, the length of the region between the second portion 34 and the inner wall of the bell mouth 18 in the direction along the rotation axis can be set to 1 mm or more and 5 mm or less. It is more preferably 2 mm or more and 4 mm or less.

Further, in the above-described electric blower 6, the first portion 36 includes the inclined portion 26 that inclines the inclination angle θ only in the rotation direction R of the rotor blade 25 with respect to the rotation axis direction. Further, as shown in Fig. 5, the extending direction of the inclined portion 26 can be set to coincide with the direction of the rotational blade inlet relative speed (combining the peripheral speed of the rotating blade with the rotational blade inlet absolute speed). In this case, the collision loss between the leading edge of the rotating blade 25 and the main flow is reduced, and the load acting on the rotating blade 25 can be reduced.

<Operation and effect of electric vacuum cleaner>

Next, the operation of the electric vacuum cleaner will be described.

When the electric vacuum cleaner system configured as described above is supplied to the electric motor unit 9, the shaft 10 rotates. By the rotation of the shaft 10, the radial impeller 11 attached to the shaft 10 rotates, and air is taken in from the suction port 17. Thereby, the air to be cleaned is sucked into the vacuum cleaner main body 1 via the hose 2, the extension pipe 3, and the suction tool 4 connected to the vacuum cleaner body 1. The air sucked into the vacuum cleaner body 1 is collected by the dust collecting portion 5. Then, the air discharged from the dust collecting portion 5 is sucked from the suction port 17 of the radial impeller 11 through the bell mouth 18 of the electric blower 6. The air sucked by the radial impeller 11 is boosted and increased in speed by the radial impeller 11, and is rotated radially outward while rotating. The air discharged from the radial impeller 11 is a circulating flow that flows through the gap between the shroud 24 and the fan cover 16 and then flows into the suction port of the radial impeller 11 . On the other hand, most of the air discharged from the radial impeller 11 is decelerated and boosted between the blades of the fixed vane 12 of the diffuser 15. Then, the air passes through the gap 21 between the diffuser 15 and the fan cover 16. Further, the air-based returning fixed blade 13 is guided to the side of the motor unit 9, and is cooled. Motorized part 9. Then, air is discharged from the discharge hole 22 provided in the motor frame 20 to the outside of the electric blower. Next, air is discharged from the discharge port 7 provided in the vacuum cleaner body 1 to the outside of the vacuum cleaner body 1.

In the above-described electric vacuum cleaner, since the electric blower 6 having the configuration shown in Figs. 2 to 5 is used, the air is discharged from the radial impeller 11, and then flows into the radial direction through the gap between the shroud 24 and the fan cover 16. The air of the impeller 11 is supplied from the intermediate portion (groove portion 35) of the rotor blade 25 to the space between the adjacent rotor blades 25. Therefore, it is possible to suppress the occurrence of a problem that the load on the rotor blade 25 is increased due to the turbulence of the flow of the re-inflowing air. As a result, a highly efficient electric blower and an electric vacuum cleaner can be obtained. Further, in the electric blower 6 configured as described above, the flow of the air discharged from the radial impeller 11 easily flows into the fan cover 16 side of the fixed vane 12. Therefore, since the fixed vane 12 is easily decelerated and boosted, an electric vacuum cleaner including a high static pressure and high efficiency electric blower can be obtained.

<Configuration and effect of a modified example of the electric blower>

Fig. 6 is a schematic cross-sectional view showing the vertical direction of the rotor blade 25 according to a modification of the embodiment of the present invention. The electric blower including the rotor blade 25 shown in Fig. 6 basically has the same configuration as that of the electric blower shown in Figs. 2 to 5, but the shape of the inclined portion 26 of the rotor blade 25 is different. Specifically, in the rotor blade of the electric blower, the portion 26C on the side of the shield portion 24 (see FIG. 3) of the inclined portion 26 has the first inclination angle θ1 in the direction of the rotation axis. The portion 26B on the side closer to the hub 23 than the portion 26C of the inclined portion 26 has a second inclination angle θ2 in the direction of the rotation axis. The first inclination angle θ1 is larger than the second inclination angle θ2. Further, the portion 26A on the side closer to the hub 23 than the portion 26B of the inclined portion 26 has a third inclination angle with respect to the direction of the rotation axis. Third tilt angle For example, it is 0°. Therefore, the first inclination angle θ1 is larger than the third inclination angle. Further, the second inclination angle θ2 is also larger than the third inclination angle. Further, the third inclination angle may be any value as long as it is smaller than the first and second inclination angles.

By including such a configuration, the load acting on the rotor blade 25 can be effectively reduced as in the electric blowers shown in Figs. 1 to 5 .

Here, the main flow that flows into the rotor blade 25 generally flows into the hub 23 side. Therefore, the amount of air flowing into the shroud 24 side is reduced. When the amount of inflow air on the side of the shroud 24 is small, the absolute speed on the side of the shroud 24 becomes small. As a result, the relative speed on the side of the shroud 24 is more radially than the relative speed on the side of the hub 23. In the inclined portion 26 of the rotor blade 25 shown in Fig. 5 or Fig. 6, the inclination angle θ on the side of the shroud 24 (see Fig. 3) is larger than the inclination angle on the side of the hub 23, so that the air is in the radial direction. The flow is along the shape of the leading edge of the rotating blade 25. Therefore, on the side of the shroud 24 of the rotary vane 25, the collision loss between the leading edge of the rotary vane 25 and the main flow is reduced, and the load acting on the rotary vane 25 can be effectively reduced.

As described above, the electric blower 6 of the present embodiment does not use a sealing member to prevent a circulating flow that flows between the shroud 24 and the fan cover 16, but suppresses the shape or positional relationship of the shroud 24 and the fan cover 16. . Further, the circulating flow flows between the blades of the rotor blade 25 without colliding with the leading edge of the rotor blade 25. Therefore, the reduction in the load reduction effect of the rotor blade 25 caused by aging is reduced, and the performance of the passage can be maintained for a long period of time.

The electric blower as described above is not limited to an electric vacuum cleaner for home use or business, and can be applied to any machine that uses an electric blower such as a dryer. As a result, a machine with high efficiency and long life can be realized.

The embodiment of the present invention has been described above, but it is also possible Various modifications are made to the above embodiments. Further, the scope of the present invention is not limited to the above-described embodiments. The scope of the present invention is defined by the scope of the claims, and the invention is intended to be

[Industrial Applicability]

The present invention can be advantageously applied to a machine using an electric blower such as an electric vacuum cleaner or a dryer for household use and business.

10‧‧‧Axis

16‧‧‧Fan cover

18‧‧‧ bell mouth

18A‧‧‧Bottom

23‧‧·wheels

24‧‧‧ Shield

25‧‧‧Rotating blades

34‧‧‧Part 2

35‧‧‧Slots

36‧‧‧Part 1

36A‧‧‧ end face

36B‧‧‧ top surface

41, 42‧‧‧ arrows

Claims (6)

An electric blower comprising a radial impeller comprising a disc-shaped hub having a surface coupled to each other, a circular shroud and a plurality of rotating blades; the shroud facing the surface; the rotating blade Between the hub and the shroud, a plurality of sheets are disposed in the circumferential direction of the shroud, and are coupled to the hub and the shroud; and further, the radial impeller is included in the direction of the rotating shaft of the radial impeller a fan cover disposed on an outer side of the shroud; the fan cover having an opening having a center point on the rotating shaft; and further comprising an electric motor portion for rotating the radial impeller; the rotating blade is located at the opening a first portion on the inner side of the outer periphery; the first portion has an end surface facing the inner wall of the opening of the fan cover; and the second portion of the shroud on the side of the rotation shaft is disposed Facing the end surface of the first portion; the inner wall of the opening is located between the end surface and the second portion; the gap between the inner wall of the opening and the second portion of the shroud Radial impeller exit The circulation flow path of the air flow inlet of the impeller and then radially flows of the circulating air flow into the impeller radially from the downstream side of the first portion of the rotating blade. The electric blower of claim 1, wherein the second portion of the shroud extends along the direction of the rotation axis. The electric blower of claim 2, wherein the inner wall of the opening extends along the second portion of the shroud. The electric blower according to any one of claims 1 to 3, wherein the first portion includes an inclined portion that inclines the direction of the rotation of the rotating blade toward the rotation direction of the rotating blade. An electric blower according to claim 4, wherein in the inclined portion, the portion on the shroud side has a first inclination angle in a direction of the rotation axis; and in the inclined portion, the portion on the side of the hub has the rotation shaft a second inclination angle of the direction; the first inclination angle is larger than the second inclination angle. An electric vacuum cleaner comprising: an electric vacuum cleaner body; a suction member connected to the body of the electric vacuum cleaner by a pipe and sucking air of the cleaning portion; the dust collecting portion is disposed inside the body of the electric vacuum cleaner, and the suction member An electric blower that is connected to the inside of the vacuum cleaner body and is sucked from the suction member into the dust collecting portion. The air and the discharge port are disposed outside the body of the electric vacuum cleaner, and discharge the air collected by the dust collecting portion outside the body of the electric vacuum cleaner.