JPH03138493A - Motor-driven blower - Google Patents

Abstract

PURPOSE:To improve the air quantity and vacuum degree by installing an inducer for smoothly feeding air into an impeller, lower than the height of the shroud of the impeller, on the inner peripheral part of the impeller. CONSTITUTION:An impeller 24 consists of a plurality of blades 25 and shroud 32 nipping the blades 25, and an impeller back plate 33. A nearly cylindrical inducer 34 having a back plate 37 having the radius of curvature in which the diameter increases toward the bottom surface in the radial direction from the axial direction and a plurality of blades 36 is arranged, separately from the impeller 24, on the inner peripheral part of the impeller 24. In this case, the height X of the inducer 34 is set lower than the height Y of the impeller shroud 32. Further, the bottom surface of the inducer 34 is closely attached on the impeller back plate 33, and the inducer 34 and the impeller 24 are simultaneously fixed on the rotary shaft of a motor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electric blower for use in a vacuum cleaner.

BACKGROUND OF THE INVENTION A conventional electric blower of this type includes an impeller 2 and an air kite 3 in a casing 1, as shown in FIG. I was starting to get it. Impeller 2 has blades 5. Shroud (composed of a 3° impeller back plate 7).

In the impeller 2 of the electric blower, the air enters in the axial direction from the suction [-1 of the impeller 2 to the arrow 13], toward the outer diameter of the impeller at a right angle. It is bent and discharged. Therefore, the air flow is not smooth, and there is a lot of loss due to collisions and friction, and the blade 5 and shroud 6
Even if we were interested in a shape like this, there was a limit to its efficiency, and a large amount of power was required to produce the specified output. Furthermore, by bending the chaos at right angles, collision,
Turbulent flow occurred and noise was likely to be generated.

The present invention solves these problems and aims to provide a highly efficient electric blower.

Means for Solving the Problems To achieve the above object, the technical means of the present invention includes a motor having a motor frame provided with an intake hole, and an impeller and an air kite attached to the front of the motor frame. The impeller is equipped with a casing, and the impeller has a plurality of blades sandwiching the blades. The inner periphery of the impeller consists of a back plate with a thick curvature radius, and a back plate with a large radius of curvature. A substantially cylindrical inducer having blades is provided, and the height of the inducer is set lower than the height of the impeller shroud, and the bottom surface of the inducer is in close contact with the impeller back plate, and the rotation speed provided in the motor is The inducer and impeller are fixed to the shaft at the same time.

Effect This technical means works as follows. In other words, since this impeller has an inducer on the inner circumference, the flow is smooth from the axial direction to the radial direction, reducing loss, increasing air volume, and greatly improving efficiency. . In particular, the large pressure exerted by the impeller"-4
If it is necessary, enter the ratio of input diameter and exit diameter.
-1 must be small, but since the impeller has a small inlet diameter and the inducer is installed lower than the shroud of the impeller, efficiency can be improved while securing the flow path area.

Moreover, since the flow becomes smooth, the noise generated from the impeller itself, that is, the noise caused by turbulence and the collision noise are reduced. Furthermore, the sound propagating forward is insulated by the inducer, resulting in a low noise level.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. A casing 21 houses an impeller and an air guide, which will be described later, and has an intake hole 22 opened in the center. Moreover, 23 is a motor frame to which the casing 21 is attached to the front.

24 is a centrifugal impeller having a plurality of impeller blades 25, and a gauging 21 is provided on the outer periphery of this impeller 24.
A diffuser formed by the air guide 26 and the air guide 26 is arranged to have a passage that expands toward the outer periphery, and a return passage 29 that smoothly and independently communicates with the end of the diffuser and guides the airflow to the motor intake hole 28 is provided at the end of the diffuser. It is formed. 3
0 is a commutator type motor for driving, and the airflow gradually introduced 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 is composed of an impeller blade 25, a shroud 32, and an impeller back plate 33, as shown in FIGS. 2 to 4.

Next, an inducer 34 is attached to the inner circumference of the impeller 24 to gradually change the flow direction from the axial direction to the radial direction and send air to the impeller 24. The inducer 34 is attached to the shaft 35 of the motor 30 together with the impeller 24. ing. This inducer 34 is made of resin or the like, and is formed by integrally molding a plurality of inducer plates 36, and has 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 (section C in FIG. 3).

Further, the indeuser blades 36 are connected to the blades 25 of the impeller 24 (second drawing section).

Here, the height X of the inducer 34 is lower than the sunset height Y of the impeller 24.

Next, the operation of the configuration of this embodiment will be explained. First, since the impeller 24 is a so-called centrifugal fan,
Although it is possible to increase the pressure by 1-1, it is difficult to increase the air volume while maintaining this pressure increase, so the performance limit has been low. Therefore, impeller 24
In this case, the inducer 3 is inserted into the intake hole 22 of the casing 21.
4 is provided, and an indecorator blade 36 formed on this indecorator 34 is inclined toward the rotation direction, and serves as a so-called mixed flow fan. Therefore, a large amount of air can be sent into the inch user 34.

Note that the pressure within this inducer 34 is also gradually increased by 1-1. Large air volume is Indu-9'
34 into the impeller 24, the impeller 2
4 utilizes the characteristics of 2 as a centrifugal fan to further increase the pressure. Therefore, a highly efficient impeller, ie, an electric blower, having a high capacity for both air volume and vacuum degree can be achieved.

However, in order to increase the pressure in the impeller 24, which is a centrifugal fan, it is necessary to pull the air long in the radial direction after it flows in.
It is necessary to increase the ratio of To achieve this, it is necessary to either reduce ■7 or increase M. However, if M is increased, the vacuum cleaner itself becomes thicker, making it difficult to use, and reducing consumption. The electric power will become large.Therefore, in order to make the impeller 24 high pressure, L must be made small.However, at this time, since the inducer 34 is arranged at the input L1, the high The inch user 34, which was installed for efficiency, actually becomes a hindrance to the flow.

Therefore, for a high pressure type impeller, the inducer 34
A great effect is achieved by making the height of the impeller lower than the impeller U',1.

In addition, the inducer back plate 37 changes smoothly from the vertical direction to the radial direction, making the flow smoother.
Collision noise and noise caused by turbulence are reduced, making the vacuum cleaner quieter.

Furthermore, the sound propagating forward is insulated by the inch and -za 34, and a similar effect can be obtained. Also,
According to this configuration, the height Y remains the same as that of the conventional impeller 24, and efficiency can be improved without increasing the overall length of the motor, and thus the size of the cleaner body.

Effects of the Invention The present invention provides an inch user on the inner circumference of the impeller that gradually changes the flow direction from the axial direction to the radial direction and smoothly sends air into the impeller. Compared to a pressure-type impeller with a small diameter, the overall length and external dimensions of the motor are thicker, and the air volume and degree of vacuum are both higher, resulting in a highly efficient electric blower.

Furthermore, since the flow is smooth, collision noise and noise caused by turbulence are reduced, making it possible to achieve a quieter vacuum cleaner.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a partial cross section of an electric blower showing an embodiment of the present invention, Fig. 2 is a plan view of an impeller of the electric blower, and Fig. 3 is a sectional view of the impeller. FIG. 4 is an exploded view of the same impeller, and FIG. 5 is a configuration diagram showing a part of a conventional electric blower in cross section. 21...Casing, 22...Intake hole, 24...
Impeller, 25...Blade, 30...Motor, 3
2... Shroud, 33... Impeller back plate, 34...
··inch. - Ther, 36... Inducer subl node, 37... Inducer back plate.

Claims (1)

[Claims] a motor having a motor frame provided with an intake hole;
A casing is attached to the front of the motor frame and contains an impeller and an air guide. Separately, a substantially cylindrical inducer is provided, which has a back plate with a radius of curvature that gradually increases from the axial direction toward the bottom in the radial direction, and multiple blades, and the height of this inducer is is installed lower than the height of the shroud of the impeller, the bottom surface of the inducer is in close contact with the impeller back plate, and the inducer and impeller are simultaneously fixed to a rotating shaft provided on the motor.