JP2712651B2 - 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 A conventional electric blower of this type is provided with an impeller 2 and an air guide 3 in a casing 1 as shown in FIG. 6, for example. Was to get. The impeller 2 includes a blade 5, a shroud 6, and an impeller back plate 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, loss due to collision and friction is large, and the efficiency is limited even in consideration of the shape of the blade 5, the shroud 6, and the like, and large power consumption is required to produce a predetermined output. Needed.

In addition, the impeller 2 is designed to change the relationship between the output, the air volume, and the degree of vacuum by changing the shape of the blade 5 and the shroud 6 and the blade 5, but a vacuum cleaner using this electric blower is designed. It is necessary to change the impeller 2 every time depending on the specification, which is wasteful in terms of design and cost. Furthermore, when the flow is bent at a right angle, collision and turbulence occur, and noise is easily generated.

An object of the present invention is to provide a high-efficiency, low-noise, high-pressure type electric blower.

Means for Solving the Problems To achieve the above object, the present invention comprises a casing containing an impeller and an air guide, and a motor for rotating the impeller, wherein the impeller has a plurality of blades and sandwiches the blades. Inducer back plate and a plurality of inducer blades, whose diameter is gradually increased from the axial direction to the bottom in the radial direction from the axial direction, apart from the impeller, are formed on the inner periphery of the shroud and impeller back plate. With the arrangement having an inducer, the bottom surface of the inducer is in close contact with the impeller back plate, and the inducer and the impeller are fixed to a rotating shaft provided in the motor,
The diameter of the inducer is gradually reduced from the tip end toward the shroud of the impeller at a portion protruding forward from the impeller.

Operation In the above configuration, since the inner periphery of the impeller has the inducer, the flow is smooth from the axial direction to the radial direction, the loss can be reduced, the air volume is increased, and the efficiency is greatly improved. . In addition, the height of the inducer is set higher than the height of the shroud of the impeller, and the outer diameter is reduced as the height of the inducer is reduced, so that the flow velocity in the inducer is further increased, and further higher efficiency is achieved. Thus, a high-pressure electric blower can be obtained.

Embodiment Hereinafter, a basic electric blower will be described with reference to the accompanying drawings. 1 to 4, reference numeral 21 denotes a casing, and an intake hole 22 is opened at the center. The opposite side of the intake hole 22 is attached to the motor frame 23 so that there is no air leakage. Numeral 24 is a centrifugal impeller having a plurality of blades 25, and a diffuser formed by a casing 21 and an air guide 26 is arranged on the outer periphery of the impeller 24 so as to have a passage that expands toward the outer periphery. A return passage 29 is formed to smoothly and independently communicate with the end of the motor and guide the airflow to the motor intake hole 28.
Reference numeral 30 denotes a commutator type motor for driving, and the airflow flowing into the motor intake hole 28 is discharged from the exhaust hole 31 while cooling the inside of the motor.

In the present embodiment, the impeller 24 includes a blade 25, a shroud 32 sandwiching the blade 25, and an impeller back plate 33, as shown in FIGS.

Next, on the inner peripheral portion of the impeller 24, an inducer 34 that gradually changes the flow direction from the axial direction to the radial direction and sends air to the impeller 24 is attached, and is fastened to the shaft 35 of the motor 30 together with the impeller 24. ing. The inducer 34 is formed of a resin or the like, and a plurality of inducer blades 36 are integrally formed and have a substantially cylindrical shape. The inducer back plate 37 of the inducer 34 has an R shape, and is smoothly connected to the impeller back plate 33 (FIG. 3, part C). The inducer blade 36 is connected to the blade 25 of the impeller 24 (D in FIG. 2).

Next, the operation of the above configuration will be described. First, since the impeller 24 is a so-called centrifugal fan, it is possible to increase the pressure, but it is difficult to increase the air volume while maintaining this pressure increase, so that the performance limit is low. Therefore, in the impeller 24, as shown in the drawing, an inducer 34 is provided in the intake hole 22 of the casing 21, and an inducer blade 36 formed in the inducer 34 is inclined toward the rotation direction. Plays a role as a so-called mixed flow fan. Therefore, a large air volume can be sent into the inducer 34.

The pressure in the inducer 34 is gradually increasing. After a large air volume is sent to the impeller 24 by the inducer 34, the pressure in the impeller 24 is further increased by utilizing the characteristics of the centrifugal fan. Accordingly, a high-efficiency impeller having a high air volume and a high degree of vacuum, that is, an electric blower is achieved.

Depending on the shape of the inducer blade 36 of the inducer 34, it is possible to design the inducer 34 not only to increase the air volume but also to increase the pressure, and to use the same impeller 24 for the inducer 34. By simply replacing 34, the required characteristics of a vacuum cleaner equipped with this electric blower can be adjusted.

For example, in the main carpet cleaning,
A large air volume type is required to suck in the garbage in the carpet, and a large air volume type can be used separately from a vacuum type in which a relatively heavy garbage needs to be sucked. That is, the design can be made more efficient and the cost can be reduced, and an inexpensive vacuum cleaner can be provided.

Furthermore, in a vacuum cleaner that does not require high efficiency, the inducer 34 may be eliminated, and only the impeller 24 may be used.
Further cost reduction can be achieved. Also, the inducer back plate
37 changes smoothly from the vertical direction to the radial direction,
Since the flow is smooth, collision noise and noise due to turbulence are reduced, and the noise as a vacuum cleaner can be reduced. Also,
The sound transmitted to the front is blocked by the inducer 34, and the same effect can be obtained. 1 to 4
In the drawing, the height of the inducer 34 projects above the shroud 32 of the impeller 24.

This is to increase the wind speed while the air flows through the inducer 34 to increase the pressure, and to obtain a high-pressure type high-efficiency impeller.

The basic configuration is as described above. Next, an embodiment of the present invention will be described with reference to FIG. As shown in part E of FIG. 6, the inducer 34 is provided with a slope such that the outer shape becomes smaller toward the lower side.
The wind speed can be further increased and the pressure can be increased further than the above-described one shown in the figure, and a high pressure type impeller can be obtained.

In addition, an inducer ring 38 is provided on the inclined portion of the inducer 34 so as to cover the outer shape. This is to prevent leakage from the inducer 34, and FIG. When the inducer 34 is provided in the same manner, the leakage is completely eliminated, and the performance further increases.

Advantageous Effects of the Invention The present invention has the following effects by arranging an inducer on the inner periphery of an impeller, which gradually changes the flow direction from the axial direction to the radial direction and smoothly sends air to the impeller. can get.

Both the air volume and the degree of vacuum increase, and a highly efficient electric blower can be provided. Further, since the flow of the air current becomes smooth, the noise due to the collision noise and the turbulent flow is reduced. Furthermore, the wind speed increases and the pressure can be increased by reducing the outer diameter of the inducer as the height decreases.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a part of a basic electric blower, FIG. 2 is a plan view of the impeller, FIG. 3 is a sectional view of FIG. 2, and FIG. 4 is an exploded view of the impeller. FIG. 5 and FIG. 5 are cross-sectional views of an impeller showing an embodiment of the present invention, and FIG. 6 is a configuration diagram showing a cross section of a part of a conventional electric blower. 21 ... casing, 22 ... intake hole, 24 ... impeller, 25
…… Blade, 30 …… Motor, 32 …… Shroud, 33…
… Impeller back plate, 34 …… Inducer, 36 …… Inducer blade, 37 …… Inducer back plate.

Claims (1)

(57) [Claims] An impeller includes a casing including an impeller and an air guide, and a motor for rotating the impeller. The impeller includes a plurality of blades, a shroud for sandwiching the blades, and an impeller back plate. In the peripheral part, apart from the impeller, an inducer having an inducer back plate whose diameter gradually increases from the axial direction to the bottom in the radial direction and an inducer having a plurality of inducer blades are arranged. The bottom is in close contact with the impeller back plate,
An electric blower in which an inducer and an impeller are fixed to a rotating shaft provided in a motor, and the diameter of the inducer gradually decreases from a tip end toward a shroud of the impeller at a protruding portion forward of the impeller.