JP2002349485A - Fan and electric blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive fan suitable for high speed rotation. SOLUTION: This fan comprises a first plate 42 having in its central part a connecting hole 42a that passes a rotating shaft 27 and is connected to the rotating shaft 27, a second plate 44 that has an intake port 43a in its central part and is disposed, facing the first plate 42, a plurality of blades 44 that hold both plates at a predetermined interval and are connected to both plats 42 and 43. The first plate 42 that is directly connected to the rotating shaft 27 and can neglect increase of rotation unbalance of the entire fan 41 is made of iron based metal, thereby reducing cost. The second plate 43 and the each blade 44 are made of aluminum alloy, thereby reducing the weight and centrifugal force in rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric blower used as an air transfer source for, for example, an industrial blower or a vacuum cleaner, and to a centrifugal fan provided in the blower.

[0002]

2. Description of the Related Art A centrifugal fan includes a first plate connected to a rotating shaft and a second plate having an intake port, as typified by a fan provided in an electric blower of a vacuum cleaner. It is formed from a number of blades provided between the plates by connecting the plates. Both plates and each blade are made of the same material, iron-based metal,
Or, it is made of an aluminum alloy. Each blade sandwiched between the two plates is swaged by twisting the swaging protrusions integrally projecting at a plurality of locations through the through holes provided in the plates. A flow path is formed between adjacent blades.

[0003] The rotational imbalance of this type of centrifugal fan with respect to the rotating shaft is affected by the component accuracy and assembly accuracy of both plates and blades. In particular, the precision of the second plate connected to the rotation shaft via the first plate and each blade is greatly affected, and the mass of the fan itself is greatly affected.

[0004] Therefore, even when assembled with the same precision, a fan made of an iron-based metal having a larger mass than a fan made of an aluminum alloy has a larger rotational imbalance.
When the rotational imbalance is large, the vibration becomes more intense as the rotational speed increases, and the vibration noise also increases. In addition, since the lateral pressure applied to the bearing supporting the rotating shaft to which the fan is attached with the vibration increases, the life of the electric blower is likely to be shortened.
In addition, the higher the number of revolutions, the greater the centrifugal force acting on the crimped convex portion of the twisted iron-based metal, and the lower the reliability of crimping. Therefore, a fan made of an iron-based metal is not suitable as a fan for an electric blower required to rotate at a high speed of, for example, 30000 rpm or more.

[0005] Such disadvantages can be remedied by a fan made of an aluminum alloy, but the cost of the aluminum alloy is high. Therefore, it is not suitable for reducing the cost of the fan and the electric blower.

[0006]

An object of the present invention is to provide an inexpensive fan and electric blower suitable for high-speed rotation.

[0007]

SUMMARY OF THE INVENTION A fan according to the present invention has a first plate through which a rotating shaft is passed and having a connecting hole at the center connected to the rotating shaft, and a suction port at the center. A fan provided with a second plate arranged opposite to the first plate and a plurality of blades arranged so as to be connected to the two plates while holding the two plates at a predetermined interval. .

In order to solve the above-mentioned problem, the invention according to claim 1 is that at least the first plate of the first and second plates is formed of an iron-based metal, and each of the blades is It is characterized by being formed of a material having a lower specific gravity than an iron-based metal.

In the present invention and each of the following inventions, the iron-based metal is a metal containing iron as a main component, and a light metal or a synthetic resin can be used as a material having a smaller specific gravity. It can be suitably used. Further, in the present invention and each of the following inventions, the connection between the first and second plates and each blade can be performed by mechanical crimping, welding, adhesive bonding, heat caulking or the like.

In the first aspect of the present invention, since at least the first plate of the first and second plates connected to the rotating shaft is made of an iron-based metal, the entire fan is made of an aluminum alloy. Material cost can be reduced. Although the first plate made of an iron-based metal has a large mass, this plate is directly connected to the rotation shaft passed through the connection hole, so that the eccentricity of the first plate with respect to the rotation shaft is substantially. Can be ignored. Therefore, the fact that the first plate made of an iron-based metal increases the rotational imbalance can be ignored. Further, since each blade connecting the first and second plates is made of a material lighter than iron-based metal, the mass of the entire fan can be made smaller than that made of iron-based metal, and the centrifugal force during rotation can be reduced. Can be reduced.

According to another aspect of the present invention, there is provided a semiconductor device comprising:
The invention according to the invention is characterized in that the first plate and each of the blades are formed of an iron-based metal, and the second plate is formed of a material having a specific gravity smaller than that of the iron-based metal.

In the present invention, since the first plate and each blade are made of an iron-based metal, the material cost can be reduced as compared with the case where the whole fan is made of an aluminum alloy. Although the first plate made of an iron-based metal has a large mass, this plate is directly connected to the rotation shaft that is passed through the connection hole.
The eccentricity of the plate is substantially negligible. For this reason, it can be ignored that the first plate made of an iron-based metal increases the rotational imbalance. Further, since the second plate is made of a lighter material than the iron-based metal, the mass of the entire fan can be made smaller than that made of the iron-based metal, and the centrifugal force during rotation can be reduced.

[0013] In order to solve the above-mentioned problems, a third aspect of the present invention is provided.
The electric blower according to the invention relates to a stator, a rotor disposed inside the stator, a frame supporting a rotation shaft of the rotor via a bearing, and a rotation shaft passing through the frame. 3. A fan according to claim 1 or 2, which is connected to one end of the fan, and a fan cover having an air inlet facing the air inlet of the fan and covering the fan and attached to the frame. Features.

According to the present invention, since the fan of claim 1 or 2 having a small rotational unbalance is provided, it can be operated with low vibration and low noise, and can be mounted on the bearing via the rotary shaft with the reduction of the centrifugal force of the fan. The applied lateral pressure can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 10 denotes an electric blower, and a frame 11 of the blower 10 includes a frame body 12 and a case end plate 13. The frame body 12
It has a cylindrical shape with a bottom, and has an annular flat surface portion 14 that extends outward integrally at one end opening edge thereof, and a fitting cylindrical portion 15 bent from the flat surface portion 14. The case end plate 13 has a ventilation opening (not shown) formed between a side edge thereof and the edge of the one end opening, is provided radially across the one end opening, and has a ventilation hole 13a. I have. Bearings 16 and 17 are attached to the center of the case end plate 13 and the center of the bottom wall of the frame body 12, respectively.

In the frame body 12, a stator 21 is housed and fixed, and a rotor 22 disposed inside the housing is housed.
Are attached, and these and the frame 11 form an electric motor section. A plurality of air paths 24 (only one is shown) are formed between the outer surface of the stator core of the stator 20 and the inner surface of the frame body 12. These airways 2
Numeral 4 is communicated with the air intake port (not shown) and with an exhaust port 25 formed on the bottom wall side of the frame body 12.

The rotor 22 has a rotating shaft 27, and a commutator 28 is attached to the shaft 27. Rotary axis 2
7 is rotatably supported by bearings 16 and 17. The pair of brush devices 23 are attached to the frame main body 12 from the outside so as to face the air passage 24. The carbon brushes 23 provided in these brush devices 23
a is pressed against the outer peripheral surface of the commutator 28 by a spring.

The rotating shaft 27 is mounted on the bearing 1 on the case end plate 13 side.
6 and protrudes out of the frame 11, and a distal end of the centrifugal fan 4 described later via a nut 29.
1 are connected. The fan 41 is rotated at a high speed of 30,000 rpm or more by the electric motor unit, for example, 350 rpm.
The rotation is performed at 00 rpm to 39000 rpm.

Between the fan 41 and the annular flat portion 14,
A current plate 32 made of synthetic resin is arranged to cover one end opening of the frame body 12. The central portion of the current plate 32 is screwed to the case end plate 13. A plurality of rectifying blades (not shown) bent in an arc shape are formed on the frame side of the rectifying plate 32, and a plurality of rectifying blades surrounding the fan 41 are provided on the fan 41 side. The wind blown out from the air is made static by the diffuser passage between the adjacent straightening vanes, and is led to the wind inlet (not shown).

The fan 41 and the rectifying plate 32 are covered with a sheet metal fan cover 33 fitted to and fitted to the fitting tube portion 15. The fan cover 33 has a suction port 33a at the center thereof facing a suction port described later.

Next, the fan 41 will be described in detail with reference to FIGS. The fan 41 is formed of a plurality of, for example, two types of materials, for example, an iron-based metal, and a light metal having a lower specific gravity, for example, an aluminum alloy.

That is, the fan 41 is formed by connecting a first plate 42 made of an iron-based metal, a second plate 43 made of an aluminum alloy, and a number of blades 44 also made of an aluminum alloy. ing.

As shown in FIG. 2, the outer shape of the first plate 42 is circular, and a connection hole 42a through which the rotating shaft 27 is formed is formed in the center of the plate 42. The diameter of the connection hole 42a is substantially equal to the diameter of the rotating shaft 27. This first plate 42 is conventionally (0. 0) to reduce the weight of the fan 41.
5 mm), for example, 0.35 mm. The outer shape of the second plate 43 is also circular and has the same diameter as the first plate 42. At the center of the second plate 43, the intake port 4 is provided.
3a is formed, and the intake port 43a is arranged so as to be close to and communicate with the intake port 33a of the fan cover 33 in an assembled state of the electric blower.

Each blade 44 formed in an arc shape
Is arranged between the first and second plates 42 and 43 and connected thereto. An example of this connection is shown in FIG. Specifically, caulking holes 42b and 43b formed of narrow slit-like holes are respectively provided in the outer peripheral portion and the inner peripheral portion of both plates 42 and 43 corresponding to the thickness direction. A caulking protrusion 44b protruding along the width direction is provided integrally. And
A blade 44 is sandwiched between the plates 42 and 43, and the caulking protrusions 44b are respectively formed in the corresponding caulking holes 4.
After being inserted through 2b and 43b, each caulking projection 44b is twisted as shown by an arrow in FIG. 3 (B) to mechanically caulk so that the caulking projection 44b does not come off from the caulking holes 42b and 43b. I have. Thereby, the fan 41 is assembled.

Between the adjacent blades 44 of the fan 41 assembled in this manner, an arc-shaped flow path that follows the curved shape of these blades 44 is formed. The inlets of these flow paths are the intake ports 43 a, and the outlets are provided to open on the peripheral surface of the fan 41. The fan 41 is directly connected to the rotary shaft 27 by passing the end of the rotary shaft 27 through the connection hole 42a and screwing the nut 29 set through the intake port 43a into the end. Have been.

When the electric blower 10 having the above configuration is operated, the fan 41 is rotated together with the rotation of the rotor 22, so that the blowing action indicated by the arrow in FIG. 1 is performed. That is, the air sucked into the flow path of the fan 41 from the suction port 33a and the air suction port 43a, and discharged from the outlet of the fan 41 is changed from the dynamic pressure to the static pressure while passing through the rectifying air path of the rectifying plate 32. After being rectified while flowing, it flows into the frame 11 through the air intake opening at one end opening of the frame body 12 covered with the rectifying plate 32. Further, the wind flows to the bottom wall side of the frame main body 12 through the air passage 24 in the frame 11, and then flows while cooling the brush device 23, and passes through the exhaust port 25 of the frame main body 12 and flows out of the frame 11. Is discharged. Such a blowing action forms a suction airflow of the vacuum cleaner.

Although the fan 41 is rotated at a high speed in the above-described blowing operation, its centrifugal force and rotational imbalance (whirling due to eccentricity with respect to the rotating shaft 27) can be reduced. That is, the fan 41 is made of a lightweight aluminum alloy because the other blades 44 and the second plate 43 are both made of a lightweight aluminum alloy, although only the first plate 42 is made of an iron-based metal. it can. Moreover, the second plate 43, which is connected to the rotating shaft 27 via the first plate 42 and the respective blades 44 and is easily eccentric with respect to the rotating shaft 27, is made of an aluminum alloy as described above and is lightweight. is there. Therefore, the centrifugal force associated with high-speed rotation can be reduced. The first plate 42 made of an iron-based metal is closely fitted to the rotary shaft 27 and directly connected to the rotary shaft 27 using the nut 29 despite its large mass. The eccentricity is substantially negligible. Therefore, the fact that the first plate 42 increases the rotational imbalance of the entire fan 41 can be ignored.

As described above, the centrifugal force and the rotational imbalance of the fan 41 can be reduced, so that the caulking projection 44b is prevented from being deformed by the centrifugal force even at high speed rotation, and the vibration and vibration noise caused by the rotational imbalance. Can be reduced. In addition, with the reduction of the vibration, the side pressure applied to the bearings 16 and 17, particularly the bearing 16 closer to the fan 41 via the rotary shaft 27 is reduced.
Can be prevented from being shortened. Therefore, the electric blower 10 having the above configuration is suitable for using the fan 41 while rotating the fan 41 at high speed.

Further, since the first plate 42 of the fan 41 connected to the rotating shaft 27 is made of an iron-based metal as described above, the material cost is reduced as compared with the case where the whole fan 41 is made of an aluminum alloy. It can be obtained inexpensively.

In the present embodiment, since the blades 44 are made of an aluminum alloy as described above, the blades 44 can be made thinner than those made of an iron-based metal. 41 is also excellent in that the flow path cross-sectional area can be increased and the air volume can be increased.

Next, another embodiment of the present invention will be described with reference to FIGS. 1 to 3 referred to in the above embodiment. The configuration of this embodiment differs from the above-described embodiment in the following points. That is, in this other embodiment, the first plate 42 and each blade 44 of the fan 41 are formed of an iron-based metal, and the second plate 43 is formed of an aluminum alloy. Except for this point, the configuration is the same as that of the first embodiment.

Since the fan 41 having such a configuration is also formed by using an iron-based metal and an aluminum alloy, the weight can be reduced and the centrifugal force during high-speed rotation can be reduced.
Accordingly, the reliability of the caulking at the caulking protrusion 44b can be maintained. Since the second plate 43, which has the greatest influence on the rotational imbalance, is made of an aluminum alloy and is lightweight, the rotational imbalance can be reduced, and accordingly, it can be operated with low vibration and low noise even at high speed rotation. In addition, the lateral pressure on the bearings 16 and 17 can be reduced to prevent the life thereof from being shortened. In addition, since not only the first plate 42 but also each blade 44 is formed of an iron-based metal, the material cost can be further reduced as compared with the above-described embodiment, and the blade can be obtained at a low cost.

FIGS. 1 to 3 referred to in the embodiment.
Still another embodiment of the present invention will be described with reference to FIG. The configuration of this embodiment differs from the above-described embodiment in the following points. That is, in this still another embodiment, the fan 41
The first and second plates 42 and 43 are made of an iron-based metal, and each blade 44 is made of an aluminum alloy. Except for this point, the configuration is the same as that of the first embodiment.

Since the fan 41 having such a structure is also formed by using an iron-based metal and an aluminum alloy, the weight can be reduced and the centrifugal force during high-speed rotation can be reduced.
Accordingly, the reliability of the caulking at the caulking protrusion 44b can be maintained. And, since the weight is reduced, the rotational imbalance can be made smaller than that of a fan made entirely of iron-based metal, so that it can be operated with low vibration and low noise even at high speed rotation, and It is possible to reduce the side pressure applied to 16 and 17 to prevent the service life from being shortened. Moreover,
Since not only the first plate 42 but also the second plate 43 are formed of an iron-based metal, the material cost can be further reduced as compared with the above-described embodiment, and the cost can be reduced.

In the above-described embodiment, the electric motor unit of the electric blower has a brush, but is not limited to this.
It may be a brushless motor unit.

[0037]

According to the first and second aspects of the present invention, the first and second plates and the plurality of blades are not made of the same material, but are made of a ferrous metal member. Since it is made of low specific gravity material, all members are made lighter than those made of ferrous metal, and in addition to being able to reduce the centrifugal force during rotation,
Since it is negligible that the first plate made of an iron-based metal increases the rotational imbalance, it is suitable for high-speed rotation. In addition, since at least the first plate is made of an iron-based metal, it is possible to provide an inexpensive fan as compared with a fan in which all members are made of an aluminum alloy.

According to the third aspect of the invention, since the fan according to the first or second aspect has a small rotational imbalance,
It can be operated with low vibration and low noise, and the side pressure applied to the bearing via the rotating shaft is small with the reduction of the centrifugal force of the fan,
Therefore, an inexpensive electric blower suitable for high-speed rotation can be provided.

[Brief description of the drawings]

FIG. 1 is a side view showing an electric blower according to an embodiment of the present invention in a partially sectional view.

FIG. 2A is a perspective view showing a centrifugal fan provided in the electric blower of FIG. 1; (B) is a plan view showing the centrifugal fan with a part cut away. FIG. 2C is a sectional view taken along line ZZ in FIG.

FIG. 3A is an exploded perspective view showing a caulking stopper of the centrifugal fan of FIG. 2; (B) is a perspective view which shows the assembly of the crimping | stopping part of FIG. 3 (A).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Electric blower 11 ... Frame 16, 17 ... Bearing 21 ... Stator 22 ... Rotor 27 ... Rotating shaft 29 ... Nut 33 ... Fan cover 33a ... Suction port 41 ... Fan 42 ... 1st plate 42a ... Connection hole 43 ... No. 2 plate 43a ... intake port

Continued on the front page F term (reference) 3B006 FA02 3H033 AA02 AA13 BB02 BB06 BB20 CC01 CC03 DD12 DD26 EE10 3H034 AA02 BB02 BB06 BB20 CC01 CC03 DD01 DD24 EE10 EE12

Claims (3)

[Claims] 1. A first plate having a central portion having a connection hole through which a rotation shaft is passed and connected to the rotation shaft, and a suction hole in the center portion, which is disposed to face the first plate. And a plurality of blades arranged and connected to the two plates while holding the two plates at a predetermined interval, wherein at least one of the first and second plates is provided. A fan wherein the first plate is formed of an iron-based metal, and each of the blades is formed of a material having a lower specific gravity than the iron-based metal. 2. A first plate having a central portion having a connection hole through which a rotation shaft is passed and connected to the rotation shaft, and a suction hole in the center portion, which is disposed to face the first plate. And a plurality of blades arranged and connected to the two plates while holding the two plates at a predetermined interval, wherein the first plate and the blades are made of an iron-based metal. And a second plate formed of a material having a specific gravity smaller than that of the iron-based metal. 3. A stator, a rotor disposed inside the stator, a frame supporting a rotary shaft of the rotor via a bearing, and one end of the rotary shaft penetrating the frame. 3. A fan according to claim 1, further comprising: a fan cover having a suction port opposed to an intake port of the fan, the fan cover being attached to the frame to cover the fan. Electric blower.