JPS6146496A - Motor fan - Google Patents

Abstract

PURPOSE:To reduce leaked flow while to reduce the fluid loss due to collision against main air flow, the noise caused through vortex or peeling and to improve the efficiency by employing approximately same shape for the upper section at the suction side of fan blade and the suction side of fan cover. CONSTITUTION:An inducing section 20c is formed at the suction port 28a side of fan cover 28 of inducing section 20b projected further than the suction port 28a of fan cover 28 along the suction wall 28b of suction port 28a to be 0.002D1- 0.1D1 against the inner diameter at the inlet of fan 17. Consequently, the gap between the suction side of front fan plate 18 and the front fan plate 18 side of fan cover 28 can be narrowed to reduce the leaked flow E thus to take in main air flow D sufficiently to the inside of fan 17. As a result, the leaked flow E is reduced while the fluid loss due to collision against main air flow D or noise due to vortex or peeling can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric blower built into a vacuum cleaner or the like.

Structure of a conventional example and its problems Figures 1 and 2 show a fan section of a conventional electric blower, and 1 shows a plurality of 71 fan plates between a circular front fan plate 2 and a disc-shaped rear fan plate 3. The fan 4a has a plurality of protrusions protruding from above and below in order to fix the fan blades 4 to the front fan plate 2 and the rear fan plate 3. It is being Reference numeral 6 denotes a rotating shaft of the electric motor, which passes through the center of the rear fan plate 3.

6.7 is a washer joined to both sides of the rear fan plate 3,
Numerals 8 and 9 are tightening rings connected to the washers 6 and 7, respectively. The lower end of the lower tightening ring 9 is in contact with a bearing (not shown) of the rotating shaft 6. Therefore, by tightening the nut 10 glued to the upper end of the rotating shaft 6, the washers 6 and 7 are attached to the rear fan plate 3 via the tightening rings 8 and 9.
The fan 1 is fixed to the rotating shaft 6 by C and K. Reference numeral 11 denotes a fan cover configured to cover the fan 71, and a suction port 11a is formed in the center of the fan cover. By the way, since the fan 1 is fixed to the rotating shaft 6, it starts rotating in synchronization with the rotation of the electric motor, and air flow is generated. Air flow (mu) is fan cover 1
1 suction port 11a → center part 1a of fan 1 → outer peripheral part 1b
It starts to flow towards. In order to smooth the flow of air to the 71 fan plate 4, a power bar 1 is attached to the 71 blade 4 facing the rotation axis 6 from the front fan plate 2.
A guide portion 4b is formed that projects inward from the suction port 11a. Also, fan cover 11 and fan blade 4
The fluctuation in the vertical direction of the fan 1 (α
The distance (xl) between the tip 11b of the fan cover 11 and the upper end 4C of the fan blade, and the tip 11b of the fan cover 11 and the upper end 2a of the front fan plate 2, so that the cover 11 and 7771 do not come into contact with each other. distance from (x
l) There is a provision. The relationship is X+ Xz
＞α X+ ＞α, so forward fan play) 2 (7) Upper end 2 a
Gap between door 17 and tip 11b of cover 11 (x5)
This resulted in the occurrence of Therefore, the aforementioned air flow (
Most of A) flows out in the direction of cooling the motor through the boost passage, but some of it flows out due to the gap (x3) mentioned above.
Flowing through the gap 1.2 between 1-1 and fan cover 11 (B)
The water begins to flow back to the suction port 11a. In this way, rather than being unable to exhibit sufficient performance due to the occurrence of leakage flow CB), the main air flow (A) and leakage flow (B) collide near point (C) and the air This has the disadvantage of causing noise due to unnecessary fluid loss, vortices, separation, etc.

Purpose of the Invention The present invention eliminates these conventional drawbacks. By making the upper part of the fan blade on the intake side and the suction part of the fan cover approximately the same shape, losses due to fluid leakage and turbulence are reduced. The purpose of the present invention is to provide an electric blower that is efficient and has low noise.

Structure of the Invention The electric blower of the present invention has a fan blade 71 on the suction port side that protrudes from the front 71 plate toward the rotation axis.
By forming the straight part to follow the shape of the suction port of the cover, it is possible to reduce leakage flow, reduce collisions in the main air flow, and reduce noise caused by fluid loss, eddies, separation, etc. This is what I did.

Description of examples The embodiment will be explained below based on FIGS. 3 to 6.

FIG. 3 shows an electric blower, in which the electric motor 13 is composed of a load side bracket 14 and an anti-load side bracket 15.
An air guide 16 is in contact with the surface of the load side bracket 14. 17 is a fan configured by arranging a plurality of fan blades 20 between a ring-shaped front fan plate 18 and a disc-shaped rear fan plate 19; 20a is a fan constructed by arranging a plurality of fan blades 20, the front fan plate 18, and the rear fan plate 19; This is a convex portion of the fan blade 20 that is caulked to fix the fan blades 20 and 20 to each other. Reference numeral 21 denotes a rotating shaft of the electric motor 130, which passes through the center of the rear fan plate 19. Reference numerals 22 and 23 designate washers joined to both sides of the rear fan plate 19, and reference numerals 24 and 26 designate tightening rings joined to each of the washers 22 and 23.

The lower end of the lower tightening ring 25 is connected to the bearing 2 of the rotating shaft 21.
It is in contact with 6. Therefore, by tightening the nut 2 screwed onto the upper end of the rotating shaft 21, the tightening ring 24.
Washers 22 and 23 are attached to the rear fan plate 19 via 5.
In this way, the 71 pin 17 is fixed to the rotating shaft 21.

A fan cover 28 is placed over the load-side bracket 14 to cover the air guide 16 and fan 17, and its base portion 28a' is press-fitted into the load-side bracket outer peripheral wall 14a. The fan cover 28 is formed with a suction port 28a that serves as an air inflow port. In addition, in order to smooth the air flow CD) to the fan 17, the front fan plate 18 has the fan blades 20 facing the rotation axis 21.
In addition, a protruding guide portion 20b is formed at the suction port 28a and J:p of the fan cover 28. That invitation!
A guide portion 20c is formed on the side of the suction port 28a of the cover 28 of 20b so as to run along the suction wall 28b of the suction port 28a. Here, the suction wall 28 of the guiding portion 20c
The terminal end 20d and the fan cover 28 having substantially the same shape along the direction b
The distance of the tip 28c of the front fan plate 1 is (Yl),
Let the overlap between the upper end 18a of the fan 170 and the tip 28c be (Yl)s, and the fluctuation in the same direction (vertical direction) as the rotating shaft 21 of the fan 170 be (β]. The depth to the tip 28a (
S), and the upper ends 18a and 71 of the front fan plate 18
The gap e (T) between the fan blade 28 and the fan blade 28 is
00 If the protrusion of the caulking convex part is (U), then Y, 〉β, Y
The relationship 2) O, 5) T) U is established so that even if the fan 1 fluctuates (β), it does not come into contact with the guide portion 20b of the fan V-do 20. . 18
b is the lower end of the front fan plate 18 on the suction side. Further, the length of the guiding portion 20c is set as Y5, and the inner diameter of the front 71 plate 18 is set as Dl.

In the above configuration, since the fan 17 is fixed to the rotating shaft 21, it starts rotating in synchronization with the rotation of the electric motor 13, and air flow is generated. Air flow (D) is from suction port 2sa of fan cover 28 → suction wall 28b → fan blade 2
0 through the guiding portion 26b of the fan 17.
a → It starts to flow toward the outer peripheral portion 17b. Also,
Upper end 18a of front fan plate 18 and fan cover 2
Since there is an overlap margin (Yl) of the tip 28c of the fan plate 18, the suction side of the front fan plate 18 and the fan cover 2g
It becomes possible to narrow the gap on the front fan plate 18 side. Therefore, the leakage flow (E) passing through the gap 29 between the 71-1a and the 7-tsun cover 28, which is conventional, can be reduced or eliminated. Furthermore, there is no overlap (Yl) between the upper end 18& of the front fan plate 18 and the tip 28a of the fan cover 28 as described above, and the depth S) of the tip 28c of the fan cover 28 is smaller than the upper end 18a of the front fan plate 18. If it is shallow, the gap between the suction side of the front fan plate 18 and the fan cover 28(7) 1 front 71 exhaust 18 side will be large and the leakage flow (E) will be large, as in the conventional case. The lower end 18b of the front fan plate 18 on the suction side has a large overlap margin (Yl).
When the depth S) of the tip 28c of the fan cover 28 becomes deeper than that of the fan cover 28, the effective cross-sectional area on the suction side of the fan blade 20 that sucks the airflow (D) from the suction port 28a of the fan cover 28 is reduced. , it is no longer possible to effectively draw the air flow (D) into the interior of the tube 71 .

That is, the overlap distance (Yl) between the top 418 & of the front fan plate 18 and the tip 28c of the fan cover 28
, the depth of the tip 28c of the shank cover 28 (S)
are the suction side upper end 18a and lower end 1 of the front fan plate 18.
8b is the best way to reduce the leakage flow (E), and the suction airflow (D) is sufficiently controlled by the fan 1.
7 can be pulled inside.

According to experiments, the length Y3) of the guiding part 20C is approximately 0.2 to 2.0ff711 even if there is a fluctuation of approximately 0.2 to 2.0ff711 in the same direction (vertical direction) as the rotation axis 21 of the 71-in 17.
In order to prevent the fan 0b from coming into contact with the tip 29c of the fan cover 28, and without reducing the air blowing efficiency, the fan 1
In order to ensure the minimum amount of air guiding part 20b into the inside of the T, it is preferable to set the diameter to approximately 1 mtn to 3-0 mtn.

In this embodiment, the number of fan blades 20 is 11, the outer diameter of the fan 17 is 108 mm, and the fan blades 200 are
Although the explanation was given assuming that the height of the opening part is 12.25 m1, almost the same effect can be obtained even if the number of sheets is 6 to 13, the outer diameter is 80 to 12 cm, and the height is 8 to 16 cm. .

Effects of the Invention As is clear from the embodiments described above, the present invention is achieved by forming a straight portion on the suction port side of the fan blade that protrudes from the front fan plate toward the rotation axis so as to follow the shape of the suction port of the fan cover. In addition to reducing leakage flow, it is also possible to reduce fluid loss due to collision with the main air flow and associated noise due to eddies, separation, etc., thereby providing a highly efficient and low-noise electric blower.

Note that the same effect can be obtained even if the fan blades are not necessarily straight as in this embodiment. Conversely, the same thing is true even if the wall surface of the suction part of the fan cover is not straight. By forming a portion of the suction portion of the blade and the suction portion of the fan cover so that the shapes are substantially the same, higher efficiency and lower noise can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional fan unit, FIG. 2 is a partially enlarged view thereof, FIG. 3 is a partial sectional view of an electric blower according to an embodiment of the present invention, and FIG. 4 is a sectional view of the fan unit. FIG. 5 is a partially enlarged view, and FIG. 6 is a dimensional explanatory view. 13...Electric motor, 17...Fan, 1
8...Front fan plate, 19...
Rear fan plate, 20...Fan blade, 28...Fan cover. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 6

Claims (1)

[Claims] A fan configured by arranging a plurality of fan blades between a pair of front and rear fan plates, an electric motor having a rotating shaft coupled to this fan, and a fan cover that covers the fan, and a suction part of the fan cover. The approximately straight part is 0.002D with respect to the fan inlet inner diameter D_1.
An electric blower with fan blades provided above the intake side so as to be _1 to 0.1D_1, facing the center of the rotation axis and protruding from the front fan plate.