JPS6146494A - Motor fan - Google Patents

Abstract

PURPOSE:To improve the efficiency and to prevent peeling henomena by projecting the suction port of fan blade further than the front fan plate and the suction port of fan cover toward the rotary shaft thereby leading the air flow smoothly and sufficiently into the fan. CONSTITUTION:The suction side endface 20b of fan blade 20 is formed to direct from the suction side upper endface 18a of front fan plate 18 toward the rotary shaft 21 and projects further than the wall face 28b of the suction port 28a of fan cover 28. The projection margin of fan blade 20 from the front fan plate 18 toward the rotary shaft 21 is set to be such ratio as 0.1D1-0.3D1 assuming the inner diameter at the inlet of fan 17 is D1. Consequently, air flows of B1, B2 can be led smoothly and sufficiently into the fan. As a result, the efficiency is improved while peeling phenomena is eliminated and noise is prevented.

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 the fan section of a conventional electric blower. The fan 4a is a plurality of protrusions protruding from each fan plate in order to fix the fan blades 4 to the front fan plate 2 and the rear fan plate 3. It is crushed and caulked. Reference numeral 5 denotes a rotating shaft of the electric motor, which passes through the center of the rear fan plate 3. 6 and 7 are washers joined to both sides of the rear fan plate 3, and 8 and 9 are the washers 6. Attached to each end is a tightening ring. The lower end of the lower tightening ring 9 is in contact with a bearing (not shown) of the rotating shaft 5. Therefore, by tightening the nut 10 screwed onto the upper end of the rotating shaft 5, the washers 6 and 7 are brought into close contact with the rear fan plate 3 via the tightening ring 8.9, thereby causing the fan 1 to be attached to the rotating shaft 5.
is fixed. 11 is a fan cover configured to cover the fan 1, and has a suction port 11. a
is formed. By the way, since the fan 1 is fixed to the rotating shaft 5, it starts rotating in synchronization with the rotation of the electric motor, and air flow occurs. The flow of air is from the inlet 11a of the fan cover 11 to the center 1a of the fan 1.
→It starts to flow toward the outer circumferential portion 1b. Most of the air flows out through the boost passage in the direction of cooling the electric motor. In this way, the air moves due to the rotation of the fan 1, but the suction end surface 4b of the fan blade 4, which is the inlet for the air flow of the fan 1, is closer to the rotation axis 6 than the inlet wall 11b of the fan cover 11. Since the fan blades are farther away from each other, the air inflow is closer to the front fan plate 2 than the rear fan plate 3 in the 71-in-1, and the fan blades 4 are unable to draw in sufficient air, resulting in insufficient performance. I couldn't make it work. In addition, since sufficient air flow is not obtained, air separation occurs on the surfaces of the fan blades 4, the front fan plate 2, and the rear fan plate 3 (particularly on the rear fan plate 3).
The problem was that abnormal sounds were generated.

OBJECTS OF THE INVENTION The present invention solves these conventional drawbacks, and by making the fan blades protrude from the rotation shaft on the suction side, airflow can be drawn smoothly and sufficiently into the fan.
To provide an electric blower FA that is efficient and does not generate abnormal noise.

Structure of the Invention The electric blower of the present invention has the suction port of the fan blade protruding toward the rotation axis from the front fan plate and from the suction port of the fan cover, so that the air flow can be smoothly and sufficiently connected to the fan suction section. This allows the air to be drawn into the inside of the fan efficiently, but with insufficient air, it is possible to prevent abnormal noise from the separation phenomenon that occurs between the fan plate and the fan blade surface.

Description of examples Hereinafter, the embodiment will be explained based on FIGS. 3 to 5.

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 nine-ring front fan plate 18
A fan 20a is constructed by arranging a plurality of fan blades 20 between the front fan plate 19 and the rear fan plate 19 in the form of a disc. This is a convex portion of the fan blade 20. Reference numeral 21 denotes a rotating shaft of the electric motor 130, which passes through the center of the rear fan plate 19. Numerals 22 and 23 are washers joined to both sides of the rear fan plate 19, and 24 and 25 are 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 nand 27 screwed onto the upper end of the rotating shaft 21, the tightening ring 24.2
6f! : The washers 22 and 23 are brought into close contact with the rear fan plate 19 through the
is fixed.

A fan cover 28 including the air guide 16 and the fan 1711 is placed over the load side bracket 14, and its base portion 28a' covers the load side bracket.

It is press-fitted into the outer peripheral wall 14a. The fan cover 28 is formed with a suction port 28a that serves as an air inflow port.

The suction side end surface 20b of the fan blade 20 is formed to face the rotation shaft 21 from the suction side upper end surface 18a of the front fan plate 18, and to protrude from the wall surface 28b of the suction port 28a of the fan cover 28. Then, the distance from the suction side upper end surface 18a of the front fan plate 18 of the fan blade 20 to the suction side end surface 20b of the fan blade 20 in the direction of the rotating shaft 21 is xl, and the distance from the suction side upper end surface 18a of the front fan plate 18 to the suction side end surface 20b of the fan blade 20 is xl. If the distance from the suction port 28a of the cover 28 to the wall surface 28b is xl, and the distance at the outer peripheral end 2281 of the griddle 22 is kXs, then xl<x, <x3
The suction side end surface 20b of the fan blade 20
Set.

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 B is generated. Air flow B is fan cover 2
8 through the suction port 2B&i of the fan 17, from the center 17& of the fan 17 toward the outer circumference 17b, and flows out in the direction of cooling the electric motor 13 through the external pressure passage such as the air guide 16. Since 20b protrudes from the suction port 28 & the rotating shaft 21 (not only because it protrudes from the front fan plate 18, it becomes easier to attract airflow), but also the airflow like B1, B2 The protrusion allows the airflow to be smoothly guided into the fan 17. In other words, sufficient air can be drawn smoothly into the fan 17, eliminating areas where the air is sparse inside the fan 17, resulting in more efficient air flow, leading to improved efficiency, and sufficient air flow. Fan grade 17 or front fan plate 18 due to lack of air flow.
It is also possible to prevent abnormal noises caused by the separation of air that occurs on the surface of the rear fan plate 19.

To explain the protrusion x1 of the fan blade 20 in the direction of the rotating shaft 21, that is, the suction side end face 20b, this protrusion x1 is from the suction side upper end face 18& of the front fan plate 18 mentioned above to the suction port 28a of the fan cover 28. If the dimension up to the wall surface 28b is less than X2, the suction side end surface 20b will be retracted from the suction port 28&, and the effect of quickly guiding the airflow flowing in from the suction port 28& into the inside of the fan 17 will work. It is desirable to set a dimensional relationship of
7 can be guided inside. However, if the protrusion x1 is too large, air stagnation occurs at the center of the fan 17, and air is prevented from flowing into the fan 17. Also, from another point of view, the protrusion x1 is the distance
By making the dimensional relationship smaller than 3, that is, X, (X3), due to the above-mentioned structure, during assembly
This prevents the problem of not being able to incorporate 20.

Therefore, according to experiments, in terms of performance) the outer diameter of the fan cover 28 is 108 mm, the inner diameter of the suction part g8a of the fan cover 28 is 33 wn, and the inner diameter of the front fan plate 18 is 36 rra.
nrIf the outer diameter of the griddle 22 is 28N, and the thickness of the fan cover 28 is O, 4m0In, then the protrusion X1 of the fan blade 20 can be set to about 5mm, which is more efficient.

In this embodiment, the number of fan blades 20 is 11.
The number of sheets is 6 to 13, the outer diameter of the fan 17 is 80 to 120, and the outer diameter of the crayon 22 is 20 to 30.
1ran1 The inner diameter D1 of the front fan rate 18 is 30~
A similar effect can be obtained by setting the protrusion x1 of the fan blade 2Q to about 6 to 10 Trrm when the rotation is about 40 mrn.

Effects of the Invention As is clear from the above-mentioned embodiments, the present invention has the following advantages:
Airflow can be drawn smoothly and sufficiently into the fan from the fan cover suction part, making it efficient and eliminating abnormal noise caused by separation between the fan plate and the fan blade surface due to insufficient air. It is possible to provide an electric blower without

[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. Figure 6 is a partially enlarged view. 13...Electric motor, 17...Fan, 1
8...Front fan plate, G, 19...
...Rear fan plate, 2o...Fan blade, 28...Fan cover. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3 Figure 4

Claims (2)

[Claims] (1) A fan configured by arranging a plurality of fan plates between a pair of front and rear fan plates, an electric motor having a rotating shaft coupled to the fan, and a fan cover that covers the fan, the fan cover An electric blower in which the fan blades in the suction section of the fan are oriented toward the center of the rotating shaft and protrude from the front fan plate. (2) A claim in which the protruding portion of the fan blade is directed from the front fan plate toward the motor rotation axis, and the protruding margin is set to be a ratio of 0.1 D_1 to 0.3 D_1 when the fan inlet inner diameter is D_1. The electric blower according to paragraph 1.