JP2666490B2 - 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 electric blower used for the vacuum cleaner rotates at a high speed of about 30,000 rpm, and in this state, turbulence as shown in part X in FIG. 6 is likely to occur. Further, such turbulence tends to generate noise.

The present invention solves such a problem, and has as its first object to provide a high-efficiency electric blower. A second object is to provide a high-pressure type high-efficiency electric blower.

Means for Solving the Problems A first technical means of the present invention for solving the above problems is:
A motor having a motor frame provided with an intake hole,
It has a casing attached to the front of the motor frame and including an impeller and an air guide.The impeller is composed of a plurality of blades, a shroud that sandwiches the blades, and an impeller back plate. Separately from the impeller, a substantially cylindrical inducer having a back plate with a radius of curvature whose diameter gradually increases from the axial direction to the bottom in the radial direction and a plurality of blades is arranged. The close contact with the impeller back plate, the inducer and the impeller are simultaneously fixed to the rotating shaft provided in the motor, and the impeller back plate is once bent upward along the outer shape of the inducer in a meridional plane shape, The inducer is configured to bend gradually downward in the radial direction so as to extend the R shape of the back plate surface.

The second technical means is that the inducer protrudes above the shroud of the impeller, and the blade of the inducer is cut off at the outer periphery at the upper end so as to extend the R shape of the shroud of the impeller. Make up.

Operation The first technical means described above operates as follows. In other words, this impeller has an inducer on the inner periphery, so that the flow is smooth from the axial direction to the radial direction, and furthermore, the impeller back plate is bent upward.
In the meridional plane shape, the radius of curvature of the inducer back plate and the impeller back plate side can be increased to the entire outer shape of the impeller, so that loss can be reduced,
The air volume can be increased, and the efficiency can be greatly improved. Further, since the flow is smooth, noise generated from the impeller itself, that is, noise due to turbulence and collision noise are reduced. In addition, the sound propagating forward is blocked by the inducer, resulting in noise reduction.

Next, as an effect of the second technical means, in order to increase the wind speed in the inducer and raise the pressure, the inducer is projected above the shroud of the impeller, but the blade of the inducer is notched. By doing so, it is possible to have one radius of curvature from the inducer to the impeller in the meridional plane shape, and the turbulent flow at the shroud inlet shown in the conventional example can be obtained by gradually changing the flow from the inducer to the impeller in the radial direction. It is possible to obtain a high-efficiency electric blower that can prevent air pressure and has a high air volume while having a high pressure.

Hereinafter, an embodiment of the present invention 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. Reference numeral 23 denotes a motor frame, on which a casing 21 is mounted. Reference numeral 24 denotes a centrifugal impeller having a plurality of blades 25, and a diffuser formed by a casing 21 and an air guide 26 is disposed 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 this embodiment, the impeller 24 is shown in FIGS.
As shown in the drawing, the blade 25 includes a blade 25, a shroud 32 sandwiching the blade 25, and an impeller back plate 33.

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 blades 36 are integrally formed to have a substantially cylindrical shape. The inducer back plate 37 of the inducer 34 has an R shape, and the impeller back plate 33 is once bent upward at the outer portion of the inducer 34, and then smoothly extended so as to be an extension of the R shape of the inducer back plate 37. Connected (third
Figure C). The blade 36 is the blade 25 of the impeller 24.
(D in FIG. 2).

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, as shown in FIG. 4, the impeller 24 is
An inducer 34 is provided, and a blade 36 formed on the inducer 34 is inclined toward the rotation direction, and plays a role as a so-called mixed flow fan.
Therefore, a large air volume can be sent into the inducer 34. Note that within this inducer 34,
The pressure is gradually increasing. Large air volume is an inducer
After being sent into the impeller 24 by 34, the pressure in the impeller 24 is further increased by utilizing the characteristics of a centrifugal fan. Accordingly, a highly efficient impeller having a high air volume and a high degree of vacuum, that is, an electric blower can be obtained.

Further, here, the back plate 37 and the impeller back plate 33 can have a very large R shape in the meridional plane shape, and can smoothly send the flow in the radial direction. Generally, the impeller has a shape similar to that of a three-dimensional impeller with extremely high efficiency, and high efficiency can be achieved.

In particular, regarding the flow, the relationship between the flow velocity and the cross-sectional area is important, and with this configuration, it is possible to design freely. 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. The sound propagating to the front is the inducer 34
As a result, the same effect can be obtained.

Next, FIG. 5 shows another embodiment, in which the inducer 34 protrudes above the shroud 32 of the impeller 24, and the blade 36 of the inducer is attached to the shroud 32 so as to have an R-shaped extension. It is notched at the outer periphery of the upper end of the portion (the notched portion is indicated by oblique lines). In addition, a casing 21 is provided according to this shape. The reason that the inducer 34 projects upward is to increase the wind speed while the air flows through the inducer 34 to increase the pressure, and a high-pressure type high-efficiency impeller, that is, an electric blower is obtained. It is something that can be done.

And, by making the meridian plane shape a smooth R shape also on the shroud 32 side, it is possible to prevent turbulent flow at the shroud 32 inlet portion, and it is possible to obtain a high-efficiency impeller with a high air flow despite high pressure, Silence is achieved.

Advantageous Effects of the Invention The present invention provides an inducer on the inner peripheral surface of an impeller, which gradually changes the flow direction from the axial direction to the radial direction to smoothly feed air to the impeller, and attaches the impeller back plate to the back of the inducer. By conforming to the R shape of the plate, it will have the same shape as the one- and three-dimensional impellers,
The degree of vacuum increases, and a high-efficiency impeller is obtained. 2. Since the flow is smooth, collision noise and noise due to turbulence are reduced, and the noise as a vacuum cleaner can be reduced. The effect is obtained.

In addition, the inducer protrudes upward from the shroud of the impeller, cuts off the outer periphery of a part of the upper end of the blade of the inducer so as to extend the R shape of the shroud, and provides a casing in accordance with this shape. Thereby, the wind speed is increased while the air flows through the inducer to increase the pressure, and a high-pressure type high-efficiency impeller, that is, an electric blower is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a cross section of a part of an electric blower showing an embodiment of the present invention, FIG. 2 is a plan view of an impeller of the electric blower, FIG. 3 is a sectional view of the same, FIG. Fig. 5 is an exploded view of the impeller, Fig. 5 is a partial sectional view of the impeller showing another embodiment of the present invention, and Fig. 6 is a sectional view showing a part of a conventional electric blower. 21 ... casing, 23 ... intake hole, 24 ... impeller, 25 ... blade, 30 ... motor, 32 ... shroud, 33 ... impeller back plate, 34 ... inducer, 36 ... blade, 37 ... back plate.

Claims (2)

(57) [Claims] 1. A motor having a motor frame provided with an intake hole, and a casing mounted in front of the motor frame and including an impeller and an air guide,
The impeller is composed of a plurality of blades, a shroud that sandwiches the blades, and an impeller back plate.Inside of the impeller, the diameter increases gradually from the axial direction to the bottom in the radial direction, apart from the impeller. A substantially cylindrical inducer having a back plate with a radius of curvature and a plurality of blades is arranged,
The bottom surface of the inducer is in close contact with the impeller back plate, and the inducer and the impeller are simultaneously fixed to the rotating shaft provided in the motor, and the impeller back plate is once bent upward along the outer shape of the inducer in a meridional plane shape. And an electric blower configured to bend gradually downward in the radial direction so as to extend the R-shape of the back plate surface of the inducer. 2. An inducer protrudes above a shroud of an impeller, and a blade of the inducer is formed by cutting off an outer peripheral portion at an upper end so as to extend an R shape of the shroud of the impeller. The electric blower according to claim 1.