JPS6131699A - Motor fan - Google Patents

Abstract

PURPOSE:To smooth the air flow by providing a step in the partition wall while positioning a starting end of a diffuser wall on the inclined face at the bottom of the diffuser thereby preventing the air flow from developing and leading along said diffuser wall to the outercircumferential direction of an air guide. CONSTITUTION:The delivery air flow from an impeller 12 is never developed quickly in vertical direction because of the effect of step provided in the partition wall 28 for separating between the return path 18 side and the diffuser 17 side and straightened smoothly without changing the flow path to the direction of motor shaft 13 at the planar section 29 on the bottom face of the diffuser 17. Then it is directed in the outercircumferential direction of an air guide 21 along the diffuser wall 22 in the downstream of the starting end 31 of the diffuser wall 22 arranged on the inclined face 30 and led to the curved section at the shoulder 27 of casing 19 and the inclined face 30 to switch the flow path smoothly in the direction of motor shaft 13 thus to improve the efficiency. While since the air flow straightened by the plane 29 will collide against the starting end 31, noise is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electric blower for generating vacuum pressure used in vacuum cleaners and the like used in general households.

Conventional Structure and Problems Conventionally, in this type of electric blower, as shown in FIG. 1, an air guide 4 including an impeller 1, a diffuser 2 surrounding the impeller 2, and a return passage 3 integrally formed; It consists of a casing 6 that covers the impeller 1 and the air guide 4, presses the upper end of the diffuser 2, and is attached to the motor bracket upper plate 6 by press fitting. or,
The air guide 4 is formed by communicating the diffuser 2, a passage 7 surrounded by a casing 6, and a return passage 3. The air discharged from the impeller 1 is routed through the diffuser 2 → passage γ → return passage 3 → motor 8 → to the exhaust port 9 of the motor.

As shown in FIG.
1 is installed upright. That is, the height of the diffuser wall 10 is considerably larger than the width of the impeller 1 in the vertical direction.

Therefore, near the outer periphery of the impeller 1, the air discharged from the impeller 1 is rapidly expanded in the vertical direction before entering the diffuser 2, resulting in increased flow loss and a decrease in air blowing efficiency. It had become.

OBJECTS OF THE INVENTION The present invention provides an electric blower that eliminates the conventional drawbacks as shown above and has high air blowing efficiency.

Structure of the Invention The electric blower of the present invention includes an impeller, an air guide, and a casing that covers these, and the air guide has a diffuser and a return passage formed integrally with a partition plate in between, The plate has a step between the surface facing the lower part of the impeller and the diffuser, which is the outer periphery of the impeller, so that the diffuser becomes higher. This diffuser has a flat plane in the direction, followed by an inclined surface, and the starting end of the diffuser wall is located on this inclined surface, and this diffuser configuration allows the air flow within the diffuser to be extremely This improves air blowing efficiency and reduces noise.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIGS. 3 to 5, reference numeral 12 denotes an impeller, which is attached to the motor shaft 13 by tightening with a nut 16 via a washer 14 and a spacer 15. A diffuser 17 that is located around the impeller 12 and guides air from the impeller 12, a return passage 18, and a casing 1 that communicates the diffuser 17 and the return passage 18.
The air guide 21 is formed integrally with the communication passage 20 surrounded by the casing 19. has been done. 24 is a motor bracket main body, in which a rotor 25, a stay, and a rotor 26 are located.

The shoulder portion 27 of the casing 19 is formed into a large arc shape, and a partition wall 28 separates the side of the air guide 21 where the din 17 is located from the side where the return passage 18 is located.
has a step on the diffuser 17 side between the surface facing the lower part of the impeller 12 and the diffuser 1 which corresponds to the outer circumference of the impeller 12, and the diffuser wall 22
The outer peripheral part of the impeller 12 where the impeller 12 is located is higher in the direction away from the motor plug throat upper plate 23 when viewed in the direction of the motor shaft 13. As shown in FIGS. 4 and 5, the bottom surface of the diffuser 1A, which is the raised part of the above-mentioned step, is provided with a flat plane 29 in the radial direction of the impeller 12 at the part near the outer periphery of the impeller 12. 29, an inclined surface 30 is provided which is inclined toward the outer periphery of the air guide 21 so as to approach the motor bracket upper plate 23 when viewed in the direction of the motor shaft 13.

Further, the starting end 31 of the diffuser wall 22 is connected to the inclined surface 3.
It has a configuration located at 0.

To explain the operation in the above configuration, the impeller 12 rotates together with the motor shaft 13 as the motor operates.

Therefore, air is sucked into the impeller 12, then discharged to the diffuser 1, flows in the order of the communication passage 20, the return passage 18, and the inside of the motor bracket body 24, and is discharged to the outside.

To explain in more detail the flow of air after it is discharged from the inopeller 12, the effect of the step provided on the partition wall 28
Di7 user 1 without sudden expansion in the vertical direction like the conventional 5
The air that has flowed into the diffuser 17 is first smoothly rectified in the direction of the motor shaft 13 at a portion 29 where the bottom surface of the diffuser 17 is flat without changing the flow path.

Continuing, the diffuser wall 2 provided on the inclined surface 3o
After the starting end 31 of 2, the air guide 21 is oriented along the diffuser wall 22 in the outer circumferential direction,
At the same time, the flow path is clearly changed in the direction of the motor shaft 13, guided by the sloped surface 30 and the rounded shape of the shoulder 27 of the casing 19.

When the air is discharged from the impeller 12 in this way, it is first rectified on the flat surface 29 to create a clean flow, and then it is transferred to the inclined surface 3.
0 and is directed toward the outer periphery of the air guide 21 along the diffuser wall 22, making the flow very smooth and improving the blowing efficiency.

In addition, the airflow rectified by the plane 29 reaches the starting end 3 of the diffuser wall.
1, the effect of reducing noise generation can also be obtained.

Effects of the Invention As is clear from the second embodiment, the electric blower of the present invention has the effect of the step provided on the partition wall and the fact that the starting end of the diffuser wall is located on the inclined surface of the bottom surface of the diffuser. As a result, the airflow discharged from the impeller does not expand rapidly, and after being rectified on the flat surface of the diffuser, it is guided to the starting end of the diffuser wall on the sloped surface, resulting in a very clean airflow.1. The air blowing efficiency can be improved, and the effect of improving the air blowing efficiency and reducing noise can be obtained.

[Brief explanation of the drawing]

Figure 1 is a cutaway perspective view of the main parts of a conventional electric blower;
The figure is a cross-sectional view of a main part of a conventional electric blower, FIG. 3 is a cross-sectional view of a main part showing an embodiment of an electric blower according to the present invention, and FIG.
The figure is also a sectional view of the air guide in one embodiment.
The figure is a partial plan view of the air guide seen from the diffuser side. 12... Impeller, 13... Motor shaft, 1
7... Diffuser, 18... Return passage, 19... Casing, 21... Air guide, 22... Diffuser wall, 28... Bulkhead plate,
29...plane, 30...slanted surface, 31...
・Start of diffuser wall. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] The air guide consists of an impeller attached to the motor shaft, an air guide that guides air from the impeller, and a casing that covers these impeller air guides.
A diffuser and a return passage are integrally formed with a partition plate in between, and a step is provided on the impeller side of the partition plate so that the diffuser is raised between the surface facing the lower part of the impeller and the diffuser, which is the outer circumference of the impeller. An electric blower in which the bottom surface of the diffuser has a flat plane in the radial direction of the impeller at a portion close to the impeller, and further forms an inclined surface, and the starting end of the diffuser wall is located on this inclined surface.