JP2758365B2 - Electric blower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example, about the electric blower that is used incorporated into the vacuum cleaner.

[0002]

2. Description of the Related Art A conventional example in which a sound absorber is provided in a part of an electric blower to reduce noise is disclosed in, for example, Japanese Utility Model Laid-Open No. 62-16797.
As disclosed in Japanese Patent Laid-Open No. H10-209, there has been proposed a technique in which a sound absorber is provided in an exhaust return path formed by an exhaust return guide vane provided on the lower surface of a differential user and an electric motor end bracket. I have.

[0003]

However, in the technique described in Japanese Utility Model Laid-Open Publication No. Sho 62-16797, a sound absorber is disposed in a narrow exhaust gas return path, so that the sound absorber becomes a ventilation resistance. However, there is a disadvantage that the performance of the electric blower is reduced.

[0004] Further, if an attempt is made to provide a large exhaust flow return flow path in order to dispose the sound absorber, the diameter of the electric blower itself in the axial direction becomes large, and there is a disadvantage that the electric blower cannot be miniaturized.

An object of the present invention, the electric blower without large-reduction, also by air flow flowing into the electric machine is reduced, resulting a insufficient cooling of the motor, resulting in to shorten the life of the electric blower There is no trouble, and the sound absorption effect is larger than before, and it is possible to reduce noise.
It is to provide an improved electric blower.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is characterized by an electric motor, a centrifugal impeller connected to a rotating shaft of the electric motor, and a diffuser disposed on the electric motor end bracket. The diffuser is located on the outer peripheral side of the centrifugal impeller, has a plurality of diffuser blades on the upper surface of the flat plate, and has exhaust flow return guide vanes on the lower surface of the flat plate, What is claimed is: 1. An electric blower, comprising: an exhaust return passage formed by a return guide blade and an electric motor end bracket, wherein the electric motor end bracket includes a bearing holding portion located at a central portion for holding a bearing of a rotor, and an annular outer periphery. A flat portion, and a support arm portion connecting the bearing holding portion and the annular flat portion are formed, and the annular flat portion is formed so as to be positioned horizontally lower than the uppermost portion of the rotor of the electric motor. Both the support arm portion, toward the center from the outer periphery of the motor end bracket,
The exhaust flow return guide vanes on the lower surface of the diff user and the exhaust flow return flow path formed by the motor bracket are formed in a convex shape toward the exhaust flow return flow passage side, and the exhaust flow return guide blades and the motor end bracket provided on the lower surface of the diff user are provided with the exhaust flow return guide vanes. On the annular flat portion in the exhaust flow return flow path thus formed ,
In the electric blower, a sound absorber is arranged below a lower end of the bearing .

[0007]

Operation As shown in FIGS.
Holding part 21a of machine end bracket 21, annular flat surface
The support arm 21c connecting the portions 21b is
Exhaust flow back from the outer periphery of the tongue 21 toward the center.
Forming a convex shape toward the flow channel side (upward in FIG. 1).
As compared with the conventional electric blower shown in FIG.
Exhaust flow return guide vane 31c and end bracket of user 31
And a cross section of the exhaust flow return flow path formed by the
Product can be increased, which allows the electric blower aerodynamic
The performance can be further improved.

In addition, according to the present invention, the electric motor 2
Of the rotor 22 is positioned lower than the top of the rotor 22 in the horizontal direction.
The sound absorber 11 is provided on the formed annular flat portion 21b,
Of the sound absorber 11 is positioned below the lower end face of the rotor bearing 23.
The rotating shaft 24 of the electric blower more than necessary.
It is possible to reduce the size of the electric blower without
You.

Further , as described above, the motor end bracket
Contact between the bearing holding portion 21a and the annular flat portion 21b of the nut 21
The supporting arm 21c is connected to the outer periphery of the end bracket 21.
From the center to the exhaust flow return channel side
The conventional electric transmission shown in FIG.
Exhaust flow return guide vanes of the diff user 31 compared to the blower
Drain formed by end bracket 31c and end bracket 21
The cross-sectional area of the air flow return channel can be increased,
The sound absorber 11 has a thickness without narrowing the return flow channel.
Since this can be disposed on the annular flat portion 21b,
Reduce noise while further improving the electric blower
Reduction can be done at the same time.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing an embodiment of an electric blower according to the present invention, and FIG. Sound absorber 1
1 is an exploded perspective view of a motor end bracket 21. FIG.

In FIG. 1, the configuration of the electric blower, which is generally designated by reference numeral 1, is roughly divided into a motor 2 and a blower 3. The end bracket 21 of the electric motor 2 is connected to a bearing holding portion 21a located at a central portion for holding a bearing 23 of the rotor 22, an annular flat surface portion 21b on the outer periphery, and the bearing holding portion 21a and the annular flat portion 21b. As shown in FIG. 2, the support arm 21c defines an opening 21d through which the exhaust flow from the blower 3 flows into the electric motor 2. And the support arm 2
1c, from the outer periphery of the end bracket 21 toward the center, an exhaust return flow channel side (upper in FIG. 1) described later.
Is formed in a convex shape.

The annular flat portion 21b is formed so as to be positioned lower than the uppermost portion of the rotor 22 of the electric motor 2 in the horizontal direction.

On the end bracket 21, a diff user 31 is arranged, and above it, a centrifugal impeller 32 is provided.
It is integrally fixed to a rotating shaft 24 of the rotor 22 by a nut 25.

Reference numeral 33 denotes a fan casing. The fan casing 33 includes a centrifugal impeller 32 and a diffuser 3.
1 is press-fitted and fixed to the outer periphery of the end bracket 21 with the cover 1 covered.

The diffuser 31 is located on the outer peripheral side of the centrifugal impeller 32, has a diffuser blade 31a on an upper surface of a flat plate 31b, and has exhaust flow return guide vanes 31c on a lower surface of the flat plate 31b. The return flow guide vane 31c, together with the end bracket 21 and the exhaust
An exhaust return path leading to d is formed. On the annular flat portion 21b of the end bracket 21, a frame 12 accommodating the sound absorbing body 11 is arranged.

As shown in FIG. 2, the frame 12 is
Is fixed integrally to the end bracket 21 by the
Notch 12a on the surface facing / contacting the return guide blade 31c
have. That is, the sound absorber 11 in the frame 12 is exposed at the portion facing the exhaust flow return flow path.

The sound absorber 11 is usually made of a porous material such as sponge or moltoprene, has flexibility, has poor workability in handling, and it is particularly difficult to automate the assembly.
This would be a manual operation, but the sound absorber 11 was
By storing it in the inside 2, handling becomes easy and assembly automation becomes possible.

In the above configuration, the air flow sucked by the centrifugal impeller 32 flows from the inner circumference to the outer circumference of the impeller 32, is discharged to the outer circumference side, and is collected by the differential user blade 31a under a static pressure. The part changes the direction of the flow path, and flows from the outer circumference to the inner circumference in the exhaust flow return flow path. At this time, the air flow includes the sound of the centrifugal impeller 32 and the blades of the diffuser blades 31a, the vortex sound generated when the exhaust flow direction is changed, and the like.
The sound is absorbed by the sound absorbing body 11 disposed at a position close to the noise generating source, that is, the sound absorbing body 11 facing the exhaust gas return flow path, and an efficient noise reduction effect is obtained.

FIG. 5 is a comparative characteristic diagram of the noise frequency generated from the prototype of the electric blower of the present invention and the conventional electric blower. A (dashed line) indicates the frequency analysis of the noise generated from the conventional electric blower. The results are shown as B (solid line).
Shows the frequency analysis result of noise generated from the prototype of the electric blower of the present invention. According to the present invention, although it depends on the sound absorbing characteristics of the sound absorbing body 11, the noise reduction effect is remarkable especially in a high frequency range of 4 KHz or more, and the overall value is 4 to 5 dB.
Noise was reduced. Further, noise in a low frequency range of 3 KHz or less is greatly affected by a rotational vibration component and the like, and it is difficult to reduce the noise with the normal sound absorber 11. However, according to the present embodiment, the noise absorber 11 is housed. Frame 12
The rigidity of the electric blower 1 is increased by the rigidity of the electric blower, the natural vibration frequency can be shifted to a high frequency range, and noise can be reduced by a resonance effect or the like.

[0020] Thus, by arranging the sound absorbing member 11 to the de Ifuyuza return exhaust stream provided on the lower surface of the 31 guide vanes 31c and the motor end bracket 21 with Manzanillo One to form exhaust flow return passage, JP-A-60-3300
As described in the electric blower described in Japanese Patent Publication No. 0, there is a problem that the outer periphery of the side wall of the fan casing is covered by the sound absorbing body (that is,
The thickness of the sound absorbing body component, bug electric blower is large-reduction in the transverse direction) can be eliminated.

[0021] In addition, the intake sound body 11, Ri due to be placed in the exhaust flow return passage of the electric blower, supra JP-A-60-3
It is not necessary to provide an exhaust passage hole in the side wall of the fan casing as in the electric blower described in Japanese Patent Publication No. 3000, and therefore, as in the electric blower described in the same publication, a part of the exhaust flow (That is, the amount of air that is discharged from the outside of the side wall of the fan casing on the side facing the exhaust passage and flows into the electric motor decreases, resulting in insufficient cooling of the electric motor and, as a result, the life of the electric blower is shortened. Shortening can solve any inconvenience.

In addition to this, AlreadyAs described above, the sound absorbing body 11
ToLocated in the exhaust air return channel of the electric blowerBy doing
The sound absorber 11 is in sufficient contact with the exhaust flow of the electric blower.
To do so, the above-mentioned JP-A-60-33000
The electric blower (ie, the exhaust passage of the fan casing)
Outside, in other words, a hole provided in the side wall of the fan casing
Exhaust flow only contacts the sound absorber outside the motor
Compared to a blower)
Can be. Then, SuckingThe sound body 11 is the noise of the electric blower.
The sound source (ie, the centrifugal impeller 32 and the diffuser)
Vortex generated when the blade sound of the wing 31a and the direction of the exhaust passage are switched
(E.g., sound flow) within the exhaust return channel
By doingNear the noise source mentioned above,
Absorbs noise before it is spread so widely around
And the sound absorbing body 11 can be
Effect of the arrangement in the exhaust flow return channel of the electric blower
The fruits are extremely large.

FIG. 3 is a longitudinal sectional view showing the centrifugal impeller, the diffuser 31 and the end bracket 21 indicated by reference numeral 32 in FIG. 1, and FIG. 4 is a sectional view of a conventional electric blower from a centrifugal impeller for comparison with FIG. Car 32 and def user 31,
FIG. 3 is a vertical sectional view showing the end bracket 21 taken out therefrom.

As shown in FIGS. 1 to 3, the support arm 21c connecting the bearing holding portion 21a and the annular flat portion 21b of the motor end bracket 21 moves from the outer periphery of the end bracket 21 to the center. Therefore, the Rukoto be formed in a convex shape toward the exhaust flow return flow path side (upper side in FIG. 1)
Thus , the cross-sectional area of the exhaust flow return flow path formed by the exhaust flow return guide vanes 31c of the diff user 31 and the end bracket 21 can be increased as compared with the conventional electric blower shown in FIG. , thereby, to further up-electric blower aerodynamic performance can mow it. In addition,
As described above, when the support arm 21c of the motor end bracket 21 is formed in a convex shape toward the exhaust flow return flow path side from the outer periphery of the end bracket 21 toward the center, the height of the end bracket 21 alone is increased. Is
It is higher than the conventional example shown in FIG. However, when viewed as an entire electric blower, this increase in size can be regarded as effectively eliminating the increase in size by effectively utilizing the space in the fan casing 33, which has conventionally been sufficient. It does not increase the vertical dimension of the electric blower.

In addition, according to the present invention, the motor 2
Of the rotor 22 is positioned lower than the top of the rotor 22 in the horizontal direction.
The sound absorber 11 is provided on the formed annular flat portion 21b,
Of the sound absorber 11 is positioned below the lower end face of the rotor bearing 23.
The rotating shaft 24 of the electric blower more than necessary.
It is possible to reduce the size of the electric blower without
You.

As described above, the motor end bracket
Contact between the bearing holding portion 21a and the annular flat portion 21b of the nut 21
The supporting arm 21c is connected to the outer periphery of the end bracket 21.
From the center to the exhaust flow return channel side
The conventional electric transmission shown in FIG.
Exhaust flow return guide vanes of the diff user 31 compared to the blower
Drain formed by end bracket 31c and end bracket 21
The cross-sectional area of the air flow return channel can be increased,
The sound absorber 11 has a thickness without narrowing the return flow channel.
Since this can be disposed on the annular flat portion 21b,
Reduce noise while further improving the electric blower
Reduction can be done at the same time.

[0027] Figure 6 obliquely bottom perspective view of Deifuyuza 31 and sound absorber 11 show a second embodiment of the electrostatic dynamic blower 7 is a longitudinal sectional view of FIG.

Thus, in the first embodiment,
Although the case where the sound absorbing body 11 is arranged on the annular flat portion 21b of the motor end bracket 21 has been exemplified, in the second embodiment shown in FIGS.
The sound absorber 11 is disposed on the back surface of the flat plate 31b that constitutes a part of the air blower 1. Also in this embodiment, the sound absorber 11 is located in the exhaust flow return flow path of the electric blower. Will be.

[0029] Figure 8 is a partially cutaway perspective view of the frame body 12 and the sound absorbing member 11 shows a third embodiment of the electrostatic dynamic blower, in the present embodiment, the first embodiment shown in FIGS. 1 and 2 As a modified example of the example, a large number of small holes 12b are provided in the surface portion (the exhaust flow return flow path side) of the frame body 12 housing the sound absorbing body 11, and according to the present embodiment, the first and second holes are provided. In addition to the effects common to the second embodiment, a large number of small holes 12 are formed in the frame 12.
By providing b, the rigidity of the frame body 12 can be further increased.

[0030] Figure 9 is a longitudinal sectional showing the Togo structure of the centrifugal impeller 32 and Deifuyuza 31, and the sound absorbing member 11 of a fourth embodiment of the electrostatic dynamic blower diagram, for comparison of Figure 10 and Figure 9, It is a longitudinal cross-sectional view which extracts and shows the centrifugal impeller 32 and the diff user 31 from the conventional electric blower.

In the second embodiment shown in FIGS. 6 and 7, the case where the sound absorbing body 11 is arranged on the back surface of the flat plate 31b forming a part of the diff user 31 is illustrated. In the fourth embodiment shown, an opening (see reference numeral 21d in FIG. 2) of an electric motor end bracket (see reference numeral 21d in FIG. 2) is provided on the surface of the exhaust flow return guide vane 31c constituting another part of the diff user 31. According to the present embodiment, the sound absorber (11) inclined toward the direction is disposed, and according to the present embodiment, compared with the conventional electric blower shown in FIG. It is possible to make the direction change into the return flow path smooth, to reduce the aerodynamic loss at that time, and to further reduce the noise caused by the aerodynamic loss as much as possible.

[0032]

According to the present invention, as shown in FIGS.
1 between the bearing holding portion 21a and the annular flat portion 21b.
The support arm 21c is moved from the outer periphery of the end bracket 21 to the middle.
Toward the center, the exhaust flow return flow path side (upper
4) by forming a convex shape toward
Compared with the conventional electric blower, the exhaust flow back of the diff user 31
Formed by the guide vanes 31c and the end bracket 21.
It is possible to increase the cross-sectional area of the formed exhaust flow return flow path.
This will further enhance the aerodynamic performance of the electric blower.
You can measure the tip.

In addition to this, according to the present invention, the electric motor
2 in the horizontal direction from the top of the rotor 22
The sound absorber 11 is disposed on the formed annular flat portion 21b,
This sound absorber 11 is placed below the lower end face of the rotor bearing 23.
Position, so the rotating shaft 24 of the electric blower
It is possible to reduce the size of the electric blower without extending
Wear.

As described above, the motor end bra
The space between the bearing holding portion 21a and the annular flat portion 21b of the
Connect the supporting arm 21c to the outside of the end bracket 21
From the periphery to the center, toward the exhaust return flow path side
The conventional electric motor shown in FIG.
Compared to the blower, the exhaust flow return guide wings of the diff user 31
Formed by root 31c and end bracket 21
The cross-sectional area of the exhaust flow return channel can be increased,
The sound absorber 11 has a thickness without narrowing the airflow return channel.
It can be disposed on the annular flat portion 21b.
So, while further improving the electric blower,
And at the same time,
The above three effects can be simultaneously provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of an electric blower according to the present invention.

FIG. 2 is an exploded perspective view of a frame, a sound absorbing body 11, and an electric motor end bracket 21 shown in FIG.

FIG. 3 is a longitudinal sectional view showing the centrifugal impeller, the diffuser 31 and the end bracket 21 shown in FIG.

FIG. 4 is a longitudinal sectional view corresponding to FIG. 3, showing a centrifugal impeller 32, a diffuser 31, and an end bracket 21 taken out from a conventional electric blower.

FIG. 5 is a comparative characteristic diagram of noise frequencies generated from a prototype of the electric blower of the present invention and a conventional electric blower.

FIG. 6 is an obliquely lower perspective view of a diffuser 31 and a sound absorber 11 showing a second embodiment of the electric blower of the present invention.

FIG. 7 is a longitudinal sectional view of FIG.

FIG. 8 shows a frame 1 showing a third embodiment of the electric blower according to the present invention.
FIG. 2 is a partially cutaway perspective view of 2 and a sound absorber 11.

FIG. 9 is a longitudinal sectional view showing a coupling structure of a centrifugal impeller 32, a diffuser 31, and a sound absorbing body 11 showing a fourth embodiment of the electric blower of the present invention.

FIG. 10 is a longitudinal sectional view corresponding to FIG. 9 and showing a centrifugal impeller 32 and a diffuser 31 taken out of a conventional electric blower.

[Explanation of symbols]

2 ... Electric motor, 11 ... Sound absorber, 21 ... Electric motor end bracket, 24 ... Rotating shaft, 31 ... Diffuser, 31a ... Diffuser wing, 31b ... Flat plate, 31c ... Exhaust flow return guide vane, 32 ... Centrifugal impeller.

──────────────────────────────────────────────────の Continuing on the front page (72) Koji Iwase, 502 Kandate-cho, Tsuchiura-shi, Ibaraki Prefecture Inside the Machinery Research Laboratory, Hitachi, Ltd. In-house (56) References JP-A 60-92796 (JP, U) JP-A 61-188000 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F04D 29/44 A47L 9 / 00 F04D 17/10

Claims (1)

(57) [Claims] An electric motor, a centrifugal impeller connected to a rotating shaft of the electric motor, and a diffuser disposed on an end bracket of the electric motor, wherein the diffuser is located on an outer peripheral side of the centrifugal impeller, An electric blower having a plurality of diffuser wings on an upper surface of a flat plate, and having exhaust return guide vanes on a lower surface of the flat plate, and forming an exhaust return passage by the exhaust return guide blades and an electric motor end bracket. The motor end bracket includes a bearing holding portion located at a central portion for holding a bearing of a rotor, an annular flat surface portion on an outer periphery, and a support arm portion connecting the bearing holding portion and the annular flat portion. And the annular flat portion is formed so as to be positioned lower than the uppermost portion of the rotor of the electric motor in the horizontal direction, and the support arm portion extends from the outer periphery of the electric motor end bracket toward the center. Accordingly, the exhaust flow return guide vanes on the lower surface of the diff user and the exhaust flow return guide vanes and the motor end formed on the lower surface of the diff user have a convex shape toward the exhaust flow return flow path formed by the motor bracket. On the annular flat portion in the exhaust return flow passage formed by the bracket and on the bearing
An electric blower, wherein a sound absorber is provided below a lower end .