JPH01321837A - Motor driven blower - Google Patents

Abstract

PURPOSE:To improve efficiency of an electric motor by forming a ventilating sectional area of an air guide gradually increasing toward its center part and by providing a surge-preventing protrusive part for suppressing a sudden change of the ventilating sectional area. CONSTITUTION:A flow of air delivered by a rotary fan is fed, passing through a ventilating path 6b formed by a diffuser 6a of an air guide 6. Here by making an inlet sectional area of the ventilating path 6b small (15 to 25% delivery area of the rotary fan), a pressure drop effect is applied to the stream of air, and a vacuum pressure is increased. The stream of air passing through the ventilating path 6b is allowed to smoothly flow into the inside of a motor by a surge-preventing protrusive part 7 suppressing a surging phenomenon generated in a sudden change point of the ventilating path 6b. Thus the high vacuum pressure in the point of time of the actual load can be generated, finally increasing an output, and efficiency can be improved. By suppressing the surging phenomenon, even noises of an electric motor due to the surging phenomenon can be decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric blower used in household vacuum cleaners and the like.

BACKGROUND OF THE INVENTION In recent years, output competition in vacuum cleaners and the like has become fierce, and electric blowers, which are the main components of vacuum cleaners, are also required to have high efficiency.

Hereinafter, the above-mentioned conventional electric blower will be explained with reference to the drawings.

Figures 4 and 5 show a half-sectional view of the fan section of a conventional electric blower and the external appearance of the air guide, and Figure 6 shows the airflow in a cross section taken along the -' plane in Figure 5. It is something.

In FIG. 4, 1 is a motor that rotates at high speed, 2 is a rotating fan that has a plurality of blades and rotates together with the motor 1;
3 is an air guide that is arranged parallel to the rotating fan 2, has a plurality of ventilation paths formed by a diffuser 3a, and guides the airflow from the rotating fan 2 to the motor 1; 4 is the rotating fan 2 and the air guide 3; The fan case has an air intake port 4a open in the center and is press-fitted into the bracket of the motor 1.

With the above configuration, when the motor 1 rotates, the airflow flowing in from the intake port 4a of the fan case 4 is transferred to the rotating fan 2.
The air flows into the motor 1 along the ventilation path 3b formed by the diffuser 3a of the air guide 3, and is discharged while cooling the inside of the motor 1.

Problems to be Solved by the Invention However, in the above configuration, the dephasor 3
If the length of the ventilation passage 3b due to a is short, the cross-sectional area of the ventilation changes rapidly, so when the vacuum pressure is increased in the air flow shown in Fig. 6, surging occurs between the high pressure part 5a and the low pressure part 5b. This causes a problem in that the vacuum pressure decreases and the efficiency ultimately becomes low.

In view of the above problems, the present invention suppresses the surging phenomenon under high vacuum pressure and solves the problem of improving the efficiency of the motor by simple means.

Means for Solving the Problems In order to solve the above problems, the electric blower of the present invention gradually increases the ventilation cross-sectional area of the air guide toward the center of the air guide, and suppresses sudden changes in the ventilation cross-sectional area. The air guide is provided with a surging prevention protrusion for this purpose.

Function: The above-described configuration of the present invention suppresses sudden changes in the cross-sectional area of the air guide and gradually increases the cross-sectional area of the air guide, thereby suppressing the generation of high-pressure portions and low-pressure portions under high vacuum pressure. Therefore, the surging phenomenon occurring between the high pressure section and the low pressure section can be suppressed, a decrease in vacuum pressure can be prevented, and the efficiency of the motor can be improved.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

Figures 1 and 2 show a half-sectional view of the electric blower fan section of the present invention and the external appearance of the air guide. FIG.

1 is a motor that rotates at high speed; 2 is a rotary fan having a plurality of blades; 6 is an air guide formed by a diffuser 6a and has a plurality of ventilation passages 6b; 4 is a fan case that covers the rotary fan 2 and the air guide 3. An intake port 4a is provided in the center. Under the above configuration, when the motor 1 rotates, air is sucked in from the fan case 4, and the rotating fan 2
．． The air is sent into the motor 1 through the ventilation path 6b of the air guide 6. Then, the inside of the motor 1 is discharged while being cooled.

Next, the operation of this embodiment will be explained. The airflow discharged from the rotating fan 2 is passed through the dephasor 6a of the air guide 6.
The air is sent through a ventilation passage 6b formed by. Here, by reducing the cross-sectional area of the inlet of the ventilation passage 6b (15% to 25% of the discharge area of the rotating fan), a pressure loss effect is added to the airflow and the vacuum pressure is increased. Then, the airflow passing through the ventilation path 6b is prevented by the surging prevention convex portion 7.
The surging phenomenon that occurs at the point of sudden change in is suppressed, and the fluid flows smoothly into the motor 1. As a result, the vacuum pressure at the time of actual load can be made high, which ultimately results in a high output and improved efficiency.

Furthermore, by suppressing the surging phenomenon, it was also possible to reduce the noise of the motor caused by the surging phenomenon.

Effects of the Invention As described above, the present invention gradually increases the ventilation cross-sectional area of the air guide toward the center of the air guide, and also provides a surging prevention convex portion to suppress sudden changes in the ventilation cross-sectional area. , the surging phenomenon that occurs between the high pressure part and the low pressure part under high vacuum pressure can be suppressed, a drop in vacuum pressure can be prevented, and the efficiency of the electric motor can be improved.

Furthermore, noise caused by the surging phenomenon can also be reduced, which is extremely advantageous in practical terms.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view of the fan section of an electric blower showing an embodiment of the present invention, FIG. 2 is an external view of the fan section air guide in the present invention, and FIG. Fig. 4 is a half-sectional view of the fan section of a conventional electric blower, Fig. 5 is an external view of the conventional fan air guide, and Fig. 6 is a cross-sectional view of the ventilation path in Fig. 5. It is a front view. 1... Motor, 2... Rotating fan, 4
...Fan case, 6...Air guide, 6a...Dephasor, 6b...Ventilation passage, 7...Surging prevention convex Department. Name of agent: Patent attorney Toshio Nakao and one other person
a-11 child ``S''' 4---Fan 5b-i 虱烙Fig. 3/ / 1 5a 5b Fig. 4 Fig. 5

Claims (1)

[Claims] A motor that rotates at high speed and is fixed to the motor's rotating shaft.
It has a rotating fan that rotates together with a motor, an air guide that guides airflow from the rotating fan, and a fan case that covers the rotating fan and the air guide, and the cross-sectional area of the ventilation path formed by the diffuser of the air guide is the air guide. An electric blower that gradually increases in size toward the center of the fan, and is equipped with a surging prevention protrusion to suppress sudden changes in the ventilation cross-sectional area.