JP2712652B2 - Electric blower - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric blower used for a vacuum cleaner.

2. Description of the Related Art As shown in FIG. 5, a conventional electric blower of this type is provided with an impeller 2 and an air guide 3 in a casing 1 and rotates the impeller 2 at a high speed by a motor 4 to obtain an air volume and a vacuum pressure. It was like. The impeller 2 is a blade
5, a front shroud 6 and a rear shroud 7.

Problems to be Solved by the Invention In the impeller 2 of the electric blower, the inflow of air enters the axial direction indicated by the arrow A from the suction port of the impeller 2 and is bent at a right angle in the outer diameter direction of the impeller (arrow B) and discharged. Is done. Therefore, the air flow is not smooth, the loss due to collision and friction is large, and the efficiency is limited even if the shapes of the blade 5, the front and rear shrouds 6, 7 are considered, and a predetermined output is output. Needed a large power consumption.

Further, by changing the shape of the blade 5, the front / rear shrouds 6, 7 and the like, and the blade 5 to change the relationship between the output, the air volume, and the degree of vacuum, the impeller 2 is designed.
Depending on the specifications of the vacuum cleaner using this electric blower,
Each time the impeller 2 needs to be changed, the design and cost are wasteful.

In addition, the air flow is bent at a right angle,
Collisions and turbulence occurred, and performance was reduced and noise was easily generated.

The present invention solves such a problem, and an object of the present invention is to provide a high-efficiency electric blower by improving the impeller itself.

Means for Solving the Problems Technical means of the present invention for achieving the above object include a motor, an impeller driven by the motor, an air guide for guiding an airflow from the impeller into the motor, an impeller and an air The casing includes a guide and includes a casing mounted on a motor.The impeller includes a plurality of blades and a front and rear shroud for sandwiching the blades.In the center inside of the front shroud of the impeller, separately from the impeller. A back plate whose diameter gradually increases from the axial direction to the bottom in the radial direction and an inducer portion having a plurality of blades provided on the back plate are arranged, and the inducer portion and the inducer are mounted on the rotating shaft of the motor. Some of the blades of the inducer section are mounted at a lower height from the back plate than other blades.

Operation The technical means operates as follows. That is, since the impeller has the inducer portion and smoothes the flow from the axial direction to the radial direction, the loss can be reduced, the air flow can be increased, and the efficiency can be greatly improved.

In addition, the design of the blade of the inducer unit makes it easy to obtain an electric blower having a different specification such as a large air volume type or a high pressure type while keeping the impeller as it is, and can cope with various vacuum cleaners. Therefore, efficiency of design and cost reduction can be achieved.

Further, in an electric vacuum cleaner which does not require high efficiency, the inducer section may be omitted. In this case, the cost can be further reduced, and inexpensive equipment can be provided to consumers.

Furthermore, since the air flow is smooth, noise generated from the impeller itself, that is, noise due to turbulence and collision noise are reduced.

In addition, the sound transmitted to the front of the electric blower is reduced by noise because it is blocked by the inducer.

In addition, since several blades of the inducer section have a lower height from the back plate than the other blades, it is possible to obtain an air flow rectifying action with a small inflow resistance at the inlet section, The problem of separation flow and turbulence near the back plate of the inducer can be prevented with a low-height blade.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
Description will be given based on the drawings. In the figure, reference numeral 21 denotes a casing including an impeller and an air guide, which will be described later, and an intake hole 22 is provided at the center. The other side of this intake hole 22 is a motor
The frame 23 is mounted so that there is no air leakage.
Numeral 24 is a centrifugal impeller composed of a plurality of blades 25 and shrouds 32, 33 before and after sandwiching the blades. An air guide 26 guides the airflow from the impeller 24 into the motor 30. In the air guide 26, a return passage 29 for guiding an airflow to the motor intake hole 28 is formed. The airflow flowing into the motor intake hole 28 is discharged from the exhaust hole 31 while cooling the inside of the motor.

And inside the center of the front shroud 32 of the impeller 24, apart from the impeller 24, a back plate 37 whose diameter gradually increases from the axial direction to the bottom in the radial direction and a plurality of blades 36 provided on this Substantially cylindrical inducer section 34
Is installed on the rotating shaft 35 of the motor 30 as an inducer.
34 and impeller 24 are attached at the same time. Several blades 36a of the blades 36 of the inducer section 34 have a smaller height than other blades. The blade 36 is inclined in the direction of rotation, and is considered to play a role as a so-called mixed flow fan.

The inducer section 34 is formed of resin or the like, and a plurality of blades 36 are integrally formed. The back plate 37 of the inducer section 34 has an R shape,
It is smoothly connected to the rear shroud 33 (FIG. 3, part C). The blade 36 is connected to the blade 25 of the impeller 24 (D in FIG. 2). A portion of the casing 21 corresponding to the inducer portion 34 is formed as a ring-shaped cover portion 38 and is connected to the intake hole 22.

Next, the operation of the configuration of the embodiment will be described.
First, because the impeller 24 is a so-called centrifugal fan,
Although it is possible to increase the pressure, it is difficult to increase the air volume while maintaining this pressure increase, so the performance limit was low.

Therefore, in the impeller 24, as shown in the drawing, an inducer portion 34 is provided in the intake hole 22 of the casing 21, and a blade 36 formed in the inducer portion 34 is tilted in the rotation direction. Yes, playing a role as a so-called mixed flow fan. Therefore, a large air volume can be sent into the inducer section 34. In the inducer section 34, the pressure gradually increases. After a large air volume is sent to the impeller 24 by the inducer section 34, the impeller 24 further increases the pressure by utilizing the characteristics of a centrifugal fan. Therefore, a high-efficiency impeller having high air volume and high vacuum is achieved.

Depending on the shape of the blades 36 of the inducer section 34, it is possible to design the inducer section 34 not only to increase the air volume but also to increase the pressure, so that the impeller 24
Can be adjusted to the required characteristics of the electric vacuum cleaner equipped with the electric blower simply by replacing the inducer section 34 with the same one. For example, in the case of mainly carpet cleaning, a large air volume is necessary to suck in the garbage in the carpet, and the large air volume type is used in those that need to suck relatively heavy garbage. Can be used for different types of vacuum. That is, the design can be made more efficient and the cost can be reduced, and an inexpensive vacuum cleaner can be provided.

Further, in a vacuum cleaner that does not require high efficiency, the inducer section 34 may be eliminated, and only the impeller 24 may be used, so that the cost can be further reduced.

Further, since the back plate 37 changes smoothly from the vertical direction to the radial direction, and the flow becomes smooth, the noise due to the collision sound and the turbulent flow is reduced, and the noise as a vacuum cleaner can be reduced.

In addition, the sound transmitted to the front of the electric blower is blocked by the inducer unit 34.

Some of the blades 36 of the inducer section 34 are lower in height than others. This is the blade 36 at the entrance
If a large number is provided, the inflow resistance at the inlet becomes large, and as a result, the performance is reduced. However, when the number of blades is reduced, the rectifying effect is reduced, and the air flow is separated near the back plate 37, resulting in turbulence and a significant decrease in performance. That is, a low blade 36a is provided to suppress the performance degradation, and in this embodiment, the height of the blade 36a is about 1.5 mm, which is slightly larger than the thickness of the boundary layer. The effect is that the blade 36a guides the airflow from the back plate 37 in the radial direction before the airflow separates, so that separation can be prevented.

Effects of the Invention The electric blower of the present invention has the following effects by the combination of the impeller and the inducer.

1. Both the air volume and the degree of vacuum increase, and a high-efficiency impeller can be obtained.

2. By using the same impeller and replacing the inducer part, the required characteristics of the electric vacuum cleaner equipped with this electric blower can be adjusted, and the cost reduction allows the use of an inexpensive electric vacuum cleaner. Can be provided to customers.

3. In the case of a vacuum cleaner that does not require high efficiency, an inducer may be omitted, and the cost can be further reduced.

4. By providing a blade having a reduced height in the inducer portion, the flow of the air current becomes smooth, the separation is reduced, and the performance as a vacuum cleaner can be improved. At the same time, noise can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a cross section of an electric blower according to an embodiment of the present invention, FIG. 2 is a plan view showing an impeller portion thereof, FIG. 3 is a cross-sectional view thereof, and FIG. FIG. 5 is a configuration diagram showing a cross section of a part of a conventional electric blower. 21 ... casing, 24 ... impeller, 25 ... blade,
30 ... motor, 32 ... front shroud, 33 ... rear shroud, 34 ... inducer section, 36 ... inducer blade, 37 ... back plate.

Claims (1)

(57) [Claims] A motor, an impeller driven by the motor, an air guide for guiding airflow from the impeller into the motor, and a casing including the impeller and the air guide and mounted on the motor. Consists of a plurality of blades and a shroud before and after sandwiching it.In the center of the front shroud of the impeller, apart from the impeller, the diameter gradually increases from the axial direction to the bottom in the radial direction. A back plate and an inducer part having a plurality of blades provided on the back plate are arranged, an inducer part and an impeller are attached to a rotating shaft of the motor, and several blades of the inducer part are compared with other blades. An electric blower with a lower height from the back plate.