WO2006006668A1

WO2006006668A1 - Centrifugal blower and air conditionaer with centrifugal blower

Info

Publication number: WO2006006668A1
Application number: PCT/JP2005/013039
Authority: WO
Inventors: Kanjirou Kinoshita
Original assignee: Daikin Industries, Ltd.
Priority date: 2004-07-14
Filing date: 2005-07-14
Publication date: 2006-01-19
Also published as: AU2005260828B8; JP2006194235A; AU2005260828B2; JP3879764B2; AU2005260828A1; CN1985092B; US20070251680A1; EP1783374A4; EP1783374A1; CN1985092A

Abstract

A centrifugal blower having a hub (2), to an axis section of which a rotating shaft (4a) of a motor (4) is connected, and a blade wheel (1) provided with blades (3) that are stood on the outer periphery of the hub (2) at predetermined spacings in a circumferential direction and whose front edge (3a) is inclined forward in a rotation direction, wherein a bellmouth (5) having an air suction opening (6) is provided on the air suction side of the blade wheel (1). A circulation flow f2 is formed, in which the flow flows from the blowout side of the blade wheel (1) through the rear side of the air suction opening (6) in the bellmouth (5) to the blade wheel (1) into which the flow is sucked again.

Description

Specification

Centrifugal blower and air conditioner equipped with centrifugal blower

Technical field

TECHNICAL FIELD [0001] The present invention relates to a centrifugal blower and an air conditioner equipped with the centrifugal blower.

Background art

A well-known centrifugal blower includes a hub connected to a rotating shaft of a motor, a shroud disposed to face the outer peripheral portion of the hub at a predetermined interval, and the shroud and the hub. Some have an impeller composed of a plurality of blades arranged at a predetermined interval along the circumferential direction between the outer peripheral portion (see Patent Document 1).

[0003] In addition, as a centrifugal blower that does not have a shroud, a hub in which a rotating shaft of a motor is connected to an axial center portion, and an outer peripheral portion of the hub are erected at predetermined intervals along the circumferential direction. There is an impeller comprising a plurality of blades, and a bell mouth having an air suction port is provided on the air suction side of the impeller (see Patent Document 2).

Patent Document 1: JP-A-11-101194.

Patent Document 2: JP-A-10-185238.

[0004] However, in the case of the centrifugal blower disclosed in the above-mentioned Patent Document 1, the reverse wing type centrifugal blower in which the outer diameter side end of the blade is located behind the inner diameter side end in the rotational direction of the impeller ( In other words, it has a complicated structure in which a large number of blades are arranged between the shroud and the outer periphery of the hub. Therefore, when manufacturing the impeller, it is necessary to join a separately manufactured shroud to the hub and blade integrally formed, which causes problems in mass production and cost.

On the other hand, in the case of the centrifugal blower disclosed in Patent Document 2, the forward blade type centrifugal blower in which the outer diameter side end portion of the blade is located on the front side in the rotational direction of the impeller from the inner diameter side end portion (immediately In other words, the impeller has a simple structure. However, if a spiral casing is not installed, the aerodynamic performance and the operating sound characteristics will deteriorate, which causes problems in terms of mass productivity and cost. Disclosure of the invention

[0006] The present invention has been made in view of the above points, and is excellent in mass productivity and capable of cost reduction, and is a low-noise and high-efficiency centrifugal fan and an air conditioner including the centrifugal fan Is intended to provide.

[0007] In the present invention, as a first aspect for solving the above-mentioned problems, a hub 2 in which a rotating shaft 4a of a motor 4 is connected to an axial center portion, and an outer peripheral portion of the hub 2 along a circumferential direction. An impeller 1 comprising a plurality of blades 3 standing up at a predetermined interval and having a leading edge 3a inclined forward in the rotation direction is provided, and an air suction port 6 is provided on the air suction side of the impeller 1. A centrifugal blower having a bell mouth 5 having the above-mentioned structure, which is sucked into the impeller 1 again from the blowing side of the impeller 1 through the back side of the air suction port 6 in the bell mouth 5. Circulating flow f

2 Construct so that it can be formed.

With such a configuration, for example, in an impeller 1 having a blade having a receding blade shape as typified by a turbofan, an air suction port 6 in the bell mouth 5 from the blowout side of the impeller 1. The circulating flow f force that is sucked into the impeller 1 again through the back side of the

2

It becomes.

As a result, the main air flow f passing through the blade 3 is drawn toward the tip side of the blade 3 by the circulating flow f.

1 2

As a result, the wind speed distribution at the exit portion of the blade 3 is improved, and aerodynamic performance can be improved and operation noise can be reduced.

[0010] Since the shroud is not required, the impeller 1 can be integrally formed, cost can be reduced, and mass productivity is excellent.

In the invention of the present application, as a second mode for solving the above-described problems, a hub 2 in which the rotating shaft 4a of the motor 4 is coupled to the shaft center portion, and a large number of the hub 2 are set up at predetermined intervals in the circumferential direction. The impeller 1 is composed of a blade 3 that has a leading edge 3a that is not inclined even if the front edge 3a is directed in either the forward or backward direction of rotation. A centrifugal blower in which a bell mouth 5 having a suction port 6 is disposed, and is sucked into the impeller 1 again from the blowing side of the impeller 1 through the back side of the air suction port 6 in the bell mouth 5. Circulated flow f

2 so that it can be formed.

With this configuration, for example, a blade represented by a radial plate fan In the impeller 1 provided with a circulating flow f that is sucked into the impeller 1 again from the blowout side of the impeller 1 through the back side of the air suction port 6 in the bell mouth 5 is formed.

2

Become.

As a result, the main air flow f passing through each blade 3 is drawn to the tip side of each blade 3 by the circulating flow f.

1 2

As a result, the wind speed distribution at the exit of each blade 3 is improved, and aerodynamic performance can be improved and the noise of the operation can be reduced.

[0013] Since the shroud does not require a shroud, the impeller 1 can be integrally formed, cost can be reduced, and mass productivity can be improved.

It is desirable that the entire blade 3 of the impeller 1 is inclined along the rotation direction.

According to such a configuration, each blade 3 sucks the circulating flow f formed by the ring body 20.

2 A strong circulating flow f is formed.

2

Even when the inner diameter of the air suction port 6 of the bell mouth 5 is increased, the strong circulating flow f does not enter deeply into each blade 3 and circulates smoothly in the vicinity of the ring body 20.

2

As a result, better air blowing performance can be realized.

[0015] Furthermore, the entire blade 3 in the impeller 1 can be inclined in the counter-rotating direction, that is, inclined in the opposite direction with respect to the rotating direction.

According to such a configuration, the blade 3 sucks the circulating flow f formed by the ring body 20.

2 Acts in a difficult direction.

[0016] Further, even when the inner diameter of the air suction port 6 of the bell mouth 5 is reduced, the strong circulation flow f does not enter deeply into the inside of the blade 3 and circulates smoothly in the vicinity of the ring body 20. That

2

As a result, it is possible to achieve good air blowing performance.

[0017] Further, the blade tip of the blade 3 in the impeller 1 can be inclined along the rotation direction.

2 acts in a direction that causes a strong circulation flow f.

2

[0018] Even when the inner diameter of the air suction port 6 of the bell mouth 5 is increased, the strong circulating flow f does not enter deeply into the blade 3 and circulates smoothly in the vicinity of the ring body 20. So As a result, better air blowing performance can be realized.

Furthermore, it is possible to incline the blade tip of the blade 3 in the impeller 1 to the side opposite to the rotational direction.

According to such a configuration, each blade 3 absorbs the circulating flow f formed by the ring body 20.

2 Acts in a direction where it is difficult to insert.

[0020] Further, even when the inner diameter of the air suction port 6 of the bell mouth 5 is reduced, the strong circulation flow f does not enter deeply into the inside of each blade 3, and smoothly circulates in the vicinity of the ring body 20. So

2

As a result, good air blowing performance can be achieved.

[0021] Further, the inner diameter of the air suction port 6 in the bell mouth 5 is D, and the impeller 1

0

When the inner diameter of the blade 3 is D and the outer diameter of the blade 3 is D, 0 (D—D) Z (D—D)

1 2 0 1 2 1

It can also be set to be 6.

[0022] With such a configuration, when the number of blades 3 is small (for example, when there are 5 to 15 blades), the minimum specific noise Ks can be kept low as shown in FIG. It is possible to further improve the aerodynamic performance and reduce the operation noise.

[0023] Note that when (D -D) / (D -D) ≥0.6, when the number of blades 3 is small, FIG.

0 1 2 1

As shown in B), the reverse flow f generated at the leading edge of the blade 3 becomes strong, and the circulating flow f at the trailing edge tip of the blade 3 becomes weak, impeding improvement in aerodynamic performance.

2

[0024] When 0≥ (D -D) / (D-D), when the number of blades 3 is small, Fig. 5 (A)

0 1 2 1

As shown in Fig. 2, the leading edge of the blade 3 cannot act effectively, impeding the improvement of aerodynamic performance.

[0025] Further, the inner diameter of the air suction port 6 in the bell mouth 5 is D, and the impeller 1

0

When the inner diameter of blade 3 is D and the outer diameter of blade 3, 3, ... is D, it is 0.3 (D—D) Z (D

1 2 0 1

— D) It can be set to be 0.3.

twenty one

[0026] With such a configuration, when the number of blades 3 is large (for example, 30 to 50), the minimum specific noise Ks can be kept low as shown in FIG. It is possible to further improve the aerodynamic performance and reduce the operation noise.

[0027] When (D -D) / (D -D) ≥0.3, when the number of blades 3 is large, the blade 3

0 1 2 1

The back flow generated at the leading edge becomes stronger and the circulation at the trailing edge tip of blade 3 is increased. The reflux f becomes weak and hinders the improvement of aerodynamic performance.

2

[0028] When 0.3 ≥ (D -D) / (D—D), when the number of blades 3 is large, blade 3

0 1 2 1

The leading edge of the leading edge cannot effectively work, hindering the improvement of aerodynamic performance.

Further, ring bodies 9 and 20 having a predetermined width in the centrifugal direction can be attached to the tip end in the axial direction of the blade 3 in the impeller 1. In such a configuration, the ring bodies 9 and 20 that rotate together with the impeller 1 act as a rotating disk, and the rotational flow is induced in the outlet flow of the blade 3 by the viscous action of the rotating disk. As a result, fan performance can be improved and noise can be reduced by rectifying the blowout flow and rectifying the circulation flow.

[0029] The centrifugal body width of the ring body 20 is H, and the outer diameter of the blade 3 in the impeller 1 is D.

At 2 o'clock, it can also be set so that 0.05 <ki = H / D <0.225. So configured

2

In this case, as shown in FIG. 9, the minimum specific noise Ks can be kept low, and it is possible to further improve the aerodynamic performance and reduce the operating noise.

[0030] By the way, 0. l≤ki = H / D≤0.15 is more preferable than the improvement of noise reduction.

2 Note that when ki HZD ≤ 0.05, the effect decreases and ki = H / D ≥ 0 225.

twenty two

This adversely affects the formation of the circulating flow, weakening the circulating flow at the tip of the trailing edge of the blade 3 and hindering the improvement of aerodynamic performance.

[0031] On the outlet side of the impeller 1, a mixed flow diffuser 23 for guiding the air flow from the impeller 1 to the oblique rear side may be provided. In such a configuration, it is possible to efficiently recover the static pressure of the dynamic pressure in the air flow blown from the impeller 1, and greatly contribute to performance improvement (ie, high efficiency and low noise).

[0032] Furthermore, a mixed flow centrifugal diffuser 23 for guiding the flow of air blown from the impeller 1 in the centrifugal direction from the oblique rear side may be provided on the blow side of the impeller 1. In such a configuration, it is possible to efficiently recover the static pressure of the dynamic pressure in the air flow blown out from the impeller 1 and to equalize the wind speed distribution of the blown wind, thereby improving performance (i.e., high efficiency , Low noise).

A flow through which the circulating flow f can pass on the outer peripheral side of the air suction port 6 in the bell mouth 5

2

A through space S can also be formed. It becomes fruit.

[0034] When the exit side height of each blade 3 in the impeller 1 is B and the outer diameter of the blade 3 is D,

2

B / D≥0.113 can also be set. If so configured, the exit of impeller 1

2

The problem of fluctuation of the air flow streamline f 1 on the side is eliminated, and stable performance can be obtained.

[0035] When BZD <0. 113, as the air flow increases,

2

The stream line f of the air flow fluctuates greatly, and finally the circulating flow f passes through the flow path between the blades 3.

1 2

It becomes blocked and the performance suddenly decreases.

Furthermore, the outer diameter of the hub 2 constituting the impeller 1 is smaller than the outer diameter D of each blade 3.

2 Can also be set. In such a configuration, the opening 22 is formed in the outer peripheral portion of each blade 3 on the hub side, and particularly when the above-described mixed flow diffuser 23 or mixed flow centrifugal diffuser 23 is provided, the blade 3 The blowout resistance of the air flow blown out from the fan becomes small.

[0037] When the exit side height of each blade 3 in the impeller 1 is B and the outer diameter of the blade 3 is D,

2

B / D≥0.08 can also be set. If so configured, in impeller 1

2

Even if the outlet side height B of each blade 3 is small, the problem that the air flow streamline f 1 fluctuates on the outlet side of the impeller 1 is eliminated, and stable performance can be obtained.

[0038] When BZD <0. 08, the streamline f of the air flow at the outlet side of the impeller 1 is large.

2 1 Fluctuates, and finally the circulating flow f closes the flow path between the blades 3 and the performance suddenly decreases.

2

To do.

[0039] Further, it is desirable that the number of the blades 3, 3, ... in the impeller 1 is 5 to 15. In this case, according to the present invention, as shown in FIG. 4, even when the number of blades 3 is small, the minimum specific noise Ks can be kept low, effectively improving aerodynamic performance and reducing operating noise. Can make noise.

[0040] The number of blades 3 in the impeller 1 may be 20 to 50. For example, as shown in Fig. 14 and Fig. 43, when the number of blades 3 is large, the maximum static pressure efficiency ratio can be made high, while the minimum specific noise level can be kept low. It is possible to improve performance and reduce driving noise. [0041] The number of blades 3 in the impeller 1 is desirably 30 to 72 U.

As shown in Fig. 14 and Fig. 50, when the number of blades 3 is as large as 30 to 72, the maximum static pressure efficiency ratio can be particularly effectively increased while the minimum specific noise level is reduced as much as possible. Therefore, it is possible to improve the aerodynamic performance and reduce the driving noise more effectively.

[0042] Further, in the air conditioner in which the heat exchange 15 and the blower X are arranged in the ventilation path 14 formed in the casing 13, the centrifugal blower of the above aspect is adopted as the blower X. You can also. Such a configuration greatly contributes to the improvement of performance and cost reduction as an air conditioner because the effective working effect possessed by the centrifugal fan can be exhibited.

Brief Description of Drawings

FIG. 1 is a longitudinal sectional view of a centrifugal blower X that works on the first embodiment of the present invention.

1

FIG. 2 is a front view of an impeller in a centrifugal blower X that is effective in the first embodiment.

1

[Fig. 3] (Α), (Β), and (C) are three types of modifications of the centrifugal blower X that is useful for the first embodiment.

1

It is sectional drawing which shows the principal part of an example.

[Fig. 4] Variable k = (D -D) / (D-in centrifugal blower X that is effective in the first embodiment

1 0 1 2

FIG. 6 is a characteristic diagram showing a change in minimum specific noise Ks with respect to D).

1

[FIG. 5] (A) is a cross-sectional view of the main part showing the case of k≤0, and (B) is a cross-sectional view of the main part showing the case of k≥0.6.

[Fig. 6] Vertical view of air conditioner Z incorporating centrifugal blower X, which is powerful in the first embodiment

1 1 is a cross-sectional view.

FIG. 7 is a longitudinal sectional view of a centrifugal blower X that works on the second embodiment.

2

[FIG. 8] (A) to (L) are modified examples of the centrifugal blower X that is useful for the second embodiment of the present invention.

2 is a cross-sectional view showing the main part.

[FIG. 9] The maximum for variable ki = HZD in centrifugal blower X, which is powerful in the second embodiment.

2 2 is a characteristic diagram showing changes in low specific noise ks.

[FIG. 10] Minimum for variable LZD in centrifugal blower X that is powerful in the second embodiment

twenty two

It is a characteristic figure showing change of specific noise ks. 圆 11] Vertical air conditioner Z incorporating centrifugal blower X that is powerful in the second embodiment

2 2 is a sectional view.

圆 12] A longitudinal sectional view of a centrifugal blower X that works on the third embodiment.

Three

FIG. 13 is a front view of an impeller in a centrifugal blower X that works on the third embodiment.

Three

圆 14] Variable k = (D -D) / (D-

3 0 1 2

1

[FIG. 15] Maximum specific noise for LZD in centrifugal blower X, which is powerful in the third embodiment

3 2

It is a characteristic figure showing change of sound Ks.

圆 16] Change in static pressure with respect to air volume in centrifugal blower X, which is powerful in the third embodiment

Three

FIG.

[FIG. 17] Maximum flow rate for BZD in centrifugal blower X, which is powerful in the third embodiment

3 2

FIG. 6 is a characteristic diagram showing a change in coefficient φ max (reference value = 1 when no degradation is present).

[FIG. 18] Vertical of air conditioner Z incorporating centrifugal blower X, which is powerful in the third embodiment

3 3 is a sectional view.

圆 19] A semi-longitudinal sectional view showing a modified example I of the centrifugal blower X that works on the third embodiment.

3 圆 20] A semi-longitudinal sectional view showing a modified example II of the centrifugal blower X that is useful for the third embodiment.

Three

The

圆 21] A modification of the centrifugal blower X that is useful for the third embodiment.

Three

The

圆 22] It is a semi-longitudinal sectional view of a centrifugal blower X that works on the fourth embodiment.

Four

[FIG. 23] Maximum flow rate for BZD in centrifugal blower X, which is powerful in the fourth embodiment

3 2

FIG. 6 is a characteristic diagram showing a change in coefficient φ max (reference value = 1 when no degradation is present).圆 24] A semi-longitudinal sectional view showing a modified example I of the centrifugal blower X that works on the fourth embodiment.

Four

FIG. 25 is a half longitudinal sectional view showing a modified example II of the centrifugal fan X according to the fourth embodiment.

Four

The

圆 26] A modification of the centrifugal blower X that is useful for the fourth embodiment. The

[27] A semi-longitudinal sectional view showing a modified example IV of the centrifugal blower X that is powerful in the fourth embodiment.

Four

The

圆 28] A semi-longitudinal sectional view showing a modified example V of the centrifugal blower X useful for the fourth embodiment.

Four

The

圆 29] It is a half vertical cross-sectional view of a centrifugal blower X that works on the fifth embodiment.

Five

圆 30] A semi-longitudinal sectional view showing a modified example I of the centrifugal blower X that works on the fifth embodiment.

5 圆 31] is a semi-longitudinal sectional view showing a modified example II of the centrifugal blower X that works on the fifth embodiment.

Five

The

圆 32] Half-longitudinal section showing the configuration of modified example III of centrifugal blower X that is useful for the fifth embodiment

Five

FIG.

[Fig.33] Modified example of centrifugal blower X that is useful for the fifth embodiment.

Five

FIG.

圆 34] Centrifugal blower powering the fifth embodiment is another contrast with modification III of X

Five

It is a half longitudinal cross-sectional view which shows the structure of the conventional centrifugal blower with a shroud.

[35] Contrast the noise reduction effect of modification III of centrifugal blower X that is powerful in the fifth embodiment.

Five

It is a graph shown in comparison with an example.

圆 36] It is a horizontal sectional view showing the configuration of the centrifugal blower that works on the sixth embodiment. [37] FIG. 37 is a longitudinal sectional view showing a configuration of a centrifugal blower that works on the sixth embodiment.

圆 38] It is a horizontal sectional view showing the configuration of the centrifugal blower that works on the seventh embodiment. [39] FIG. 39 is a longitudinal sectional view showing a configuration of a centrifugal blower that works on the seventh embodiment.

圆 40] It is a horizontal sectional view showing a configuration of a centrifugal blower that works on the eighth embodiment.圆 41] It is a longitudinal sectional view showing a configuration of a centrifugal blower that works on the eighth embodiment.

[42] FIG. 42 is a horizontal sectional view showing a configuration of a main part of a test example of a centrifugal blower useful for the eighth embodiment.

[43] FIG. 43 is a graph showing the relationship between the performance of the test example of the centrifugal blower according to the eighth embodiment and the number of blades. FIG. 44 is a semi-longitudinal sectional view of a test example showing the configuration of a centrifugal blower according to an eighth embodiment.

FIG. 45 is a horizontal sectional view showing a configuration of a centrifugal blower that works on the ninth embodiment.

FIG. 46 is a longitudinal sectional view showing a configuration of a centrifugal blower that works on the ninth embodiment.

FIG. 47 is a horizontal sectional view showing a configuration of a centrifugal blower that is effective in the tenth embodiment.

FIG. 48 is a longitudinal sectional view showing a configuration of a centrifugal fan that is useful for the tenth embodiment.

FIG. 49 is a horizontal sectional view showing a configuration of a main part of a test example of a centrifugal blower useful for the tenth embodiment.

FIG. 50 is a graph showing the performance of a test example of the centrifugal fan according to the tenth embodiment in relation to the number of blades.

FIG. 51 is a horizontal sectional view showing the structure of a centrifugal blower that works in the eleventh embodiment.

FIG. 52 is a longitudinal sectional view showing the structure of a centrifugal blower that works in an eleventh embodiment.

FIG. 53 is a horizontal sectional view showing the structure of a centrifugal blower that is powerful in the twelfth embodiment.

FIG. 54 is a longitudinal sectional view showing the structure of a centrifugal blower that is powerful in the twelfth embodiment.

FIG. 55 is a semi-longitudinal sectional view showing the structure of a centrifugal blower that works in the thirteenth embodiment.

FIG. 56 is a semi-longitudinal sectional view showing a configuration of a main part of a centrifugal blower working on a thirteenth embodiment.

FIG. 57 is a horizontal sectional view showing the structure and operation of the main part of the centrifugal blower working on the thirteenth embodiment.

FIG. 58 is a horizontal sectional view showing the structure and operation of the main part of the centrifugal blower working on the thirteenth embodiment.

FIG. 59 is a semi-longitudinal sectional view showing the configuration of a centrifugal fan that is useful for the fourteenth embodiment.

FIG. 60 is a horizontal sectional view showing the structure and operation of the essential parts of a centrifugal blower useful for a fourteenth embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, several preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(First embodiment) 1 to 6 show the centrifugal fan X and the centrifugal fan X according to the first embodiment of the present invention.

1 Air conditioner z is shown.

1

[0045] As shown in Figs. 1 and 2, the centrifugal blower X has a rotating shaft 4a of the motor 4 at the shaft center.

1

Are connected to a disk-shaped hub 2 and a plurality of blades 3 erected at predetermined intervals in the circumferential direction on the outer periphery of the hub 2. On the air suction side of 1, a bell mouth 5 having an air suction port 6 is disposed.

[0046] As shown in Fig. 2, the impeller 1 has its leading edge inclined forward in the rotational direction, and the outer diameter side end portion 3b of each blade 3 is located closer to the impeller 1 than the inner diameter side end portion 3a. It is a swept-blade type (that is, a turbofan type) located on the rear side of the rotational direction M. In this way, since the ratio of the static pressure increase to the total pressure increase of the impeller 1 is large, the spiral scroll becomes unnecessary.

In addition, a concave portion 2 a for accommodating the motor 4 is formed in the axial center portion of the hub 2. The motor fixing part 7 fixes the motor 4. The bearing boss 8 pivots the rotating shaft 4a of the motor 4! /. The reinforcing ring 9 connects the tip ends of each blade 3 in the axial direction.

[0048] The inner diameter D of the air suction port 6 of the bell mouth 5 is the same as that of the impeller 1.

0

It is set larger than the inner diameter D of the blade 3. The back side of the bell mouth 5 (in other words,

1

In this case, a distribution space S is formed on the outer peripheral side), and is sucked into the impeller 1 again from the blowout side of the impeller 1 through the back side of the air suction port 6 in the bell mouth 5. Circulating flow f

2 is configured so that it can be easily and reliably formed.

By the way, the shape of the air suction port 6 in the bell mouth 5 may be a straight shape as shown in FIG. 3 (A) or a wedge shape as shown in FIG. 3 (B). As shown in Fig. 3 (C), a flare shape may be used.

[0050] In the present embodiment, the inner diameter of the air inlet 6 in the bell mouth 5 is D,

0 When the inner diameter of the blade 3 in the impeller 1 is D and the outer diameter of the blade 3 is D, 0 <(D

1 2 0

D) / (D-D) <0.6. The number of blades 3 is 10

1 2 1

Has been.

[0051] In the centrifugal fan configured as described above, the following operational effects are obtained. That is, in the above-described configuration, the reinforcing rib 9 is the center, and the outer periphery of the reinforcing rib 9 is bent from the outlet side of the impeller 1. A circulating flow f is formed which is sucked into the impeller 1 again through the back side of the air inlet 6 in the lumouth 5. Therefore, the air passing through the blade 3 after being sucked in from the air suction port 6

2

The main flow f is attracted to the tip side of the blade 3 by the circulating flow f, and the outlet portion of the blade 3

1 2

The wind speed distribution in minutes can be improved, and aerodynamic performance can be improved and driving noise can be reduced. Since the shroud does not require a shroud, the impeller 1 can be integrally formed, and the cost can be reduced and the mass productivity is excellent.

[0052] In this embodiment, when the inner diameter of the air suction port 6 in the bell mouth 5 is D, the inner diameter of the blade 3 in the impeller 1 is D, and the outer diameter of the blade 3 is D, 0 <k

0 1 2

= (D -D) / (D -D) <0.6. This way, in Figure 4

0 1 2 1

As shown in the figure, the minimum specific noise Ks can be kept low, and it is possible to further improve the aerodynamic performance and lower the operating noise.

[0053] When 0≥k = (D -D) / (D-D), as shown in FIG.

0 1 2 1

The leading edge of the leading edge cannot function effectively, impeding the improvement of aerodynamic performance. When k = (D -D) / (D -D) ≥0.6, as shown in Fig. 5 (B),

0 1 2 1

As a result, the backflow generated by the

2 hinders the improvement of aerodynamic performance.

[0054] Incidentally, the inner diameter of the blade 3 in the centrifugal blower X that is useful for the present embodiment is D, the blade

1 1

The outer diameter of 3 is D, the inner diameter of the air inlet 6 is D, and the suction side center Q force of the air inlet 6 is diagonal.

2 0

Place microphone 12 at the position of lm 45 degrees forward, k = (D— D

0 1) Z (D — D) as a variable

twenty one

When the change in the minimum specific noise Ks was examined, the results shown in Fig. 4 were obtained. From the above results, it can be seen that good driving sound characteristics are obtained in the range of 0 <k <0.6.

[0055] FIG. 6 shows a ceiling-embedded air incorporating a centrifugal blower X that can be used in the present embodiment.

1

A harmony device z is shown.

1

In this case, the heat exchanger 15 and the centrifugal fan X are disposed in the air flow path 14 of the air flow W formed in the casing 13, and the motor fixing portion 7 that fixes the motor 4 is provided on the casing 13.

1

It is integrated with the top plate 13a. The air conditioner Z includes a suction grill 16, an air filter 17, a drain pan 18, and an air outlet 19.

[0056] By doing this, from the point where the effective action and effect that the centrifugal blower X has can be demonstrated, It greatly contributes to performance improvement and cost reduction as an air conditioner z. Also air

1

The optimum diameter of the suction port 6 can be made larger than that of the conventional one, and the pressure loss in the air filter 17 or the like can be kept small.

[0057] (Second embodiment)

FIGS. 7 and 11 show the centrifugal fan X and the centrifugal fan X according to the second embodiment of the present invention.

2 Air conditioner Z is shown.

2

[0058] In this case, the impeller 1 in the centrifugal blower X is provided with the reinforcing belt in the first embodiment.

2

Instead of the ring 9, a ring body 20 having a predetermined width H in the centrifugal direction is attached. Other configurations, functions, and effects are the same as those in the first embodiment, and a description thereof will be omitted.

By the way, the ring body 20 can have various shapes as shown in FIGS. 8 (A) to (L). The following is just an example, and it should be noted that shapes other than those shown in the figures can be used! ^.

That is, as shown in FIG. 8 (A), the ring body 20 may be joined to the axial end face of the blade 3, and as shown in FIG. 8 (B), the ring body 20 is anti-hub. As shown in Fig. 8 (C), the ring body 20 may be installed in a state inclined to the hub side as shown in Fig. 8 (D). As shown in FIG. 8 (E), the end of the ring body 20 in the centrifugal direction may be an arcuate surface 20a, and the end of the ring body 20 in the centrifugal direction may be an arcuate surface 20a. It may be attached in a state of being curved and inclined toward the opposite hub side. In this case, the formation of the circulation flow f is promoted by the Coanda effect.

2

[0061] Further, as shown in FIG. 8 (F), the surface of the ring body 20 on the side opposite to the hub may be a recess 20b. In this case, the formation of the circulation flow f is promoted because a negative pressure is generated in the recess 20b.

2

Further, as shown in FIG. 8 (G), the surface of the ring body 20 on the side opposite to the hub may be a recess 20b and attached to the hub in an inclined state. Also in this case, the formation of the circulation flow f is promoted as in the case shown in FIG. In addition, as shown in FIG.

2

The surface on the side of the hub may be a recess 20c. In this case, since a negative pressure is generated in the recess 20c, the formation of the circulating flow f is promoted.

2

[0062] Further, as shown in Fig. 8 (I), the hub side surface of the ring body 20 is formed as a recess 20c and the hub side It may be attached in an inclined state. Also in this case, the formation of the circulating flow f is promoted as in the case shown in FIG. Also, as shown in Fig. 8

2

It may be formed of a member having a comparatively thick thickness, and the arc surfaces 20d and 20e may be formed on the attachment portion side and the centrifugal end portion side, respectively. In this case, a smooth circulation flow f is formed.

2 Yes.

[0063] Further, as shown in FIG. 8 (K), the ring body 20 is formed of a relatively thick member, and arcuate surfaces 20d and 20e are formed on the attachment portion side and the centrifugal direction end portion side, respectively. You may make it attach in the state inclined to the hub side. Also in this case, a smooth circulating flow f can be formed as in the case shown in FIG.

2

[0064] Further, as shown in FIG. 8 (L), in the hub 2, an inclined surface 2b inclined to the anti-wing root side is formed at a portion where the blade 3 is erected, while the ring body 20 is relatively formed. An inclined surface 3c formed of a member having a thickness and formed with arcuate surfaces 20d, 20e on the attachment portion side and the centrifugal direction end portion side, respectively, and the ring body 20 formed on the tip portion of the blade 3 (the hub 2 It may be attached to the inclined surface 2b. In this case, the mold can be removed in the outer peripheral side during molding.

[0065] By the way, the outer diameter of the blade 3 in the centrifugal blower X that is useful for this embodiment is D, the ring

2 2 Body 20 centrifugal direction width is H, suction side center Q force of air suction port 6 Microphone 12 is installed at a position of lm diagonally 45 degrees forward lm, and change of minimum specific noise Ks with respect to variable ki = HZD is examined.

2

As a result, the result of FIG. 9 was obtained.

[0066] According to the above results, it can be seen that good driving sound characteristics are obtained in the range of 0.05 <ki <0.225. By the way, it is more preferable to set the range of 0.1 <ki <0.15. Note that when ki = HZD≤0.05, the effect is reduced, and when ki = H / D≥0.225, the circulation flow is adversely affected, leading to the trailing edge of blade 3 The circulation flow in the section is weakened, which hinders the improvement of aerodynamic performance.

[0067] The distance between the ring body 20 and the bell mouth 5 is L, and the minimum specific noise with respect to the variable LZD.

2

When the change of Ks was examined, the result of Fig. 10 was obtained. According to the above result, LZD≥

2

It can be seen that good driving sound characteristics are obtained in the range of 0.169.

[0068] FIG. 11 shows a ceiling-embedded air incorporating a centrifugal blower X that can be used in the present embodiment. Harmonic device Z is shown. In this case, the flow of the air flow W formed in the casing 13

2

A heat exchanger and a centrifugal blower X are arranged in the air passage 14 to fix the motor 4 that fixes the motor 4.

2

The fixed portion 7 is integrated with the top plate 13 a of the casing 13. Air conditioner Z

2, air filter 17, drain pan 18, and air outlet 19. In this way, the air conditioner Z can be used because the effective effects of the centrifugal fan X can be exhibited.

2

As a result, it greatly contributes to performance improvement and cost reduction. In addition, the optimum air inlet 6

2

The diameter can be made larger than the conventional one, and the pressure loss in the air filter 17 can be kept small.

[0069] In the case of the centrifugal blower that works in each of the above-described embodiments, the present invention is applied to one having a small number of blades 3 (that is, 5 to 15).

(Third embodiment)

FIGS. 12 to 16 show the centrifugal fan X and the third preferred embodiment of the present invention.

3 and air conditioner z are shown.

Three

[0070] As shown in Figs. 12 and 13, the centrifugal blower X has a rotating shaft of the motor 4 at the shaft center.

Three

4a is connected to a disk-shaped hub 2 and a plurality of blades 3 are provided on the outer periphery of the hub 2 at predetermined intervals along the circumferential direction. A bell mouth 5 having an air suction port 6 is disposed on the air suction side of the impeller 1.

[0071] As shown in Fig. 13, the impeller 1 has its leading edge inclined forward in the rotational direction, and the outer diameter side end 3b of each blade 3 is closer to the impeller 1 than the inner diameter side end 3a. A swept wing type (ie, turbofan type) located on the rear side of the rotational direction M. In this case, since the ratio of the static pressure increase to the total pressure increase of the impeller 1 is large, the spiral scroll can be dispensed with. In the case of the centrifugal blower X that covers the present embodiment, the number of blades 3 is the first and the second.

Three

It is set more than the number of blades in centrifugal blowers X and X

1 2

(For example, 30-50 sheets).

[0072] Further, a concave portion 2a for accommodating the motor 4 is formed in the axial center portion of the hub 2. The motor fixing part 7 fixes the motor 4. The bearing boss 8 pivotally supports the rotating shaft 4 a of the motor 4.

[0073] Further, in the impeller 1 of the present embodiment, the centrifugal method is the same as in the second embodiment. A ring body 20 having a predetermined width H is attached in the direction. In the case of the present embodiment, the ring body 20 has a shape that inclines toward the hub 2 as it applies force in the centrifugal direction.

[0074] A circulation space S is formed on the back side of the bell mouth 5 (in other words, on the outer peripheral side), and the back side of the air inlet 6 in the bell mouth 5 from the blowing side of the impeller 1 The circulating flow sucked into the impeller 1 again through

2 is configured so that it can be formed easily and reliably. As in the first embodiment, the shape of the air suction port 6 in the bell mouth 5 may be a wedge shape or a flare shape, which may be a straight shape.

[0075] In the present embodiment, the inner diameter of the air suction port 6 in the bell mouth 5 is D,

0 When the inner diameter of the blade 3 in the impeller 1 is D and the outer diameter of the blade 3 is D,

1 2

-0. 3 <(D -D) / (D -D) <0.3. In addition, feather 3

0 1 2 1

The number is 40.

[0076] In the centrifugal fan configured as described above, the following operational effects can be obtained.

That is, the circulating flow sucked into the impeller 1 again from the blowout side of the impeller 1 through the back side of the air suction port 6 in the bell mouth 5 f

2 is formed. Therefore, the main air flow f passing through the blade 3 is attracted to the tip of the blade 3 by the circulating flow f, and at the outlet portion of the blade 3.

1 2

The wind speed distribution is improved, and aerodynamic performance can be improved and driving noise can be reduced. However, since the shroud is unnecessary, the impeller 1 can be integrally formed, which can reduce the cost and is excellent in mass productivity.

In the present embodiment, when the inner diameter of the air suction port 6 in the bell mouth 5 is D, the inner diameter of the blade 3 in the impeller 1 is D, and the outer diameter of the blade 3 is D, 0.

0 1 2

3 <k = (D-D) Z (D-D) <0 · 3. If you do this,

0 1 2 1

As shown in Fig. 14, the minimum specific noise Ks can be kept low, further improving the aerodynamic performance and lowering the operating noise. In addition, —0. 3≥k = (D -D) / (D-

0 1 2

D), the leading edge of the 'BRW' does not work effectively on the blade 3 and the aerodynamic performance is improved.

1

Inhibits the top. When k = (D -D) / (D -D) ≥0.3, the front edge of blade 3

0 1 2 1

The reverse flow f generated in the

2 It becomes weaker and the improvement of aerodynamic performance is impeded. [0078] Incidentally, the inner diameter of the blade 3 in the centrifugal blower X that is useful in the present embodiment is D, and the blade

3 1

The outer diameter of 3 is D, the inner diameter of the air inlet 6 is D, and the suction side central force of the air inlet 6 is diagonal 4

2 0

Set a microphone at a position of lm 5 degrees forward, and use k = (D -D) / (D— D) as a variable.

0 1 2 1

When the change in specific noise Ks was examined, the results shown in Fig. 14 were obtained. According to the above results, it can be seen that good driving sound characteristics are obtained in the range of −0.3 <k <0.3.

[0079] Further, the relationship between the outer diameter D of the blade 3 and the centrifugal direction width H of the ring body 20 in the centrifugal fan X.

3 2

The relationship is the same as in the second embodiment. In centrifugal blower X

3 Figure 15 shows the relationship between the outer diameter D of the blade 3 and the distance L between the ring body 20 and the bell mouth 5

2

As shown, the minimum specific noise Ks can be kept low in the range of LZD≥0.07.

2

wear. At L / D <0.07, the minimum specific noise Ks increases rapidly.

2

[0080] By the way, when the height B on the exit side of each blade 3 in the impeller 1 becomes smaller, the streamline f of the air flow on the exit side of the impeller 1

The fluctuation of 1 becomes large, and finally the circulation flow f

2 blocks the flow path between the blades 3. Then, as shown by the solid line in FIG. 16, the aerodynamic performance suddenly drops and the hysteresis characteristic shown by the dotted line in FIG. 16 occurs. In this case, it is not related to the number of wings.

Therefore, in the present embodiment, BZD≥0.113 is set. Like this

2

Then, the streamline f of the air flow at the exit side of impeller 1

As shown by the two-dot chain line in Fig. 16, stable performance can be obtained. BZD <0.113

2

Then, the streamline of the air flow at the outlet side of the impeller 1 greatly fluctuates, and finally the circulating flow f closes the flow path between the blades 3 and the performance is suddenly lowered.

2

[0082] Incidentally, the maximum flow rate for BZD in centrifugal blower X, which is useful for this embodiment.

3 2

When the change in the coefficient φ max (reference value = 1 when there is no deterioration) was examined, the result shown in Fig. 17 was obtained. Where φ max = Qmax Z60 (π D B) u, u = π D N, Q

2 2 2 2 max: Total air flow (m ³ Zmin), N: Number of rotations (rpm). From the results in Figure 17, B / D≥0

2

113, it can be seen that the maximum flow coefficient φ max indicates the reference value = 1.

[0083] FIG. 18 shows a ceiling-embedded air incorporating a centrifugal blower X that is useful for the present embodiment.

Three

Harmonic device Z is shown. In this case, the flow of the air flow W formed in the casing 13 A heat exchanger and a centrifugal blower X are arranged in the air passage 14 to fix the motor 4 that fixes the motor 4.

Three

The fixed portion 7 is integrated with the top plate 13 a of the casing 13. Air conditioner Z is suction drip

3, air filter 17, drain pan 18, and air outlet 19. In this way, the centrifugal blower X

3 It can contribute to the performance improvement and cost reduction of the air conditioner Z because it has the effective effects. In addition, the air intake 6

Three

The appropriate aperture can be made larger than that of the conventional one, and the pressure loss in the air filter 17 can be suppressed to a small extent.

[0084] Next, a modified example of the centrifugal blower X that works on the third embodiment will be described.

Three

(Modification I)

As shown in FIG. 19, the tip side end portion of each blade 3 in the impeller 1 may be inclined at substantially the same inclination angle as the inclination angle of the ring body 20. Even in this case, D, D,

0 1

The relationship between D, H, L, and B is the same as described above.

2

[0085] (Modification II)

As shown in FIG. 20, the tip side end portion of each blade 3 in the impeller 1 is inclined at an inclination angle substantially the same as the inclination angle of the ring body 20, and the inlet side end portion of each blade 3 is connected to the hub. Try to tilt the impeller 1 so that it approaches the centripetal direction of the impeller 1 as you move to the side. Even in this case, the relationship between D, D, D, H, L, and B is the same as described above.

0 1 2

[0086] (Modification III)

As shown in FIG. 21, the tip side end of each blade 3 in the impeller 1 is inclined at an inclination angle substantially the same as the inclination angle of the ring body 20, and the inlet side end portion of each blade 3 is connected to the hub. It may be inclined to approach the centripetal direction of the impeller 1 as it is directed toward the side, and a selection 21 may be formed at the inlet side end. In this way, the blowing sound is reduced because the formation of the boundary layer on the blade surface is suppressed. In this case, D, D, D,

0 1 2

The relationship between H, L, and B is the same as described above.

[0087] (Fourth embodiment)

FIG. 22 shows a centrifugal blower X that can be used in the fourth embodiment of the present invention.

Four

In this case, the outer diameter D of the hub 2 constituting the impeller 1 is set smaller than the outer diameter D of each blade 3.

3 2

is doing. In this way, an opening 22 is formed in the outer peripheral portion of each blade 3 on the hub side. As will be described later, when the mixed flow diffuser 23 is provided (see FIG. 29), the blowing resistance of the air flow blown out from the blades 3 is reduced. Other configurations and operational effects are the same as those in the third embodiment, and a description thereof will be omitted.

Also in the present embodiment, as in the third embodiment, when the outlet-side height B of each blade 3 in the impeller 1 is reduced, the air flow streamlines on the outlet side of the impeller 1 f

1 fluctuates, and finally the circulating flow f closes the flow path between the blades 3, and the solid line in Fig. 16

2

As shown in Fig. 16, the aerodynamic performance suddenly decreases, and the hysteresis characteristic shown by the dotted line in Fig. 16 occurs. In this case, it is not related to the number of blades.

[0089] Therefore, in this embodiment, BZD≥0.08 is set. BZD upper limit

The reason why 2 2 is set smaller than that in the third embodiment is that the opening 22 is formed in the outer peripheral portion of each blade 3 on the hub side. This eliminates the problem of fluctuations in the air flow streamline f on the exit side of the impeller 1. As shown by the two-dot chain line in FIG.

1

The specified performance can be obtained. When BZD <0. 08, the empty space at the exit side of impeller 1

2

The streamline of the air flow fluctuates greatly, and finally the circulating flow f closes the flow path between the blades 3, 3, ...

2

Blocks and drops in performance.

[0090] By the way, the maximum flow rate for BZD in centrifugal blower X that is useful for this embodiment.

4 2

When the change of the coefficient φ max (reference value = 1 when there is no deterioration) was examined, the result shown in Fig. 23 was obtained. Where φ max = QmaxZ60 (π D B) u, u = π D N, Qmax:

2 2 2 2 Total air opening (m ³ Zmin), N: Number of revolutions (rpm). From the result of Fig. 23, B / D≥0.08

2 shows that the maximum flow coefficient φ max shows the reference value = 1.

[0091] Next, a modified example of the centrifugal blower X that works on the fourth embodiment will be described.

Four

(Modification I)

As shown in FIG. 24, the tip side end portion of each blade 3 in the impeller 1 may be inclined at substantially the same inclination angle as the inclination angle of the ring body 20. Even in this case, D, D,

0 1

The relationship between D, H, L, and B is the same as described above.

2

[0092] (Variation II)

As shown in FIG. 25, the tip side end portion of each blade 3 in the impeller 1 is inclined at substantially the same inclination angle as the inclination angle of the ring body 20, and the inlet side end portion of each blade 3 is connected to the hub. To the side Try to tilt the impeller so that it approaches the centripetal direction of the impeller 1. Even in this case, the relationship between D, D, D, H, L, and B is the same as described above.

0 1 2

[0093] (Modification III)

As shown in FIG. 26, the tip side end portion of each blade 3 in the impeller 1 is inclined at substantially the same inclination angle as the inclination angle of the ring body 20, and the inlet side end portion of each blade 3 is connected to the hub. It may be inclined to approach the centripetal direction of the impeller 1 as it is directed toward the side, and a selection 21 may be formed at the inlet side end. In this way, the blowing sound is reduced because the formation of the boundary layer on the blade surface is suppressed. In this case, D, D, D,

0 1 2

The relationship between H, L, and B is the same as described above.

[0094] (Modification IV)

As shown in FIG. 27, the impeller 1 may be a mixed flow fan type in which the outer peripheral side of the hub 2 (that is, the portion where the blade 3 is provided) is inclined. Even in this case, D, D, D

0 1 2

, H, L, and B are the same as described above.

[0095] (Variation V)

As shown in FIG. 28, the impeller 1 is a mixed flow fan type in which the outer peripheral side of the hub 2 (that is, the portion where the blade 3 is provided) is inclined, and the inlet side end of each blade 3 is connected to the hub side. Try to tilt it so that it approaches the centripetal direction of the impeller 1 as you go. Even in this case, the relationship between D, D, D, H, L, and B is the same as described above.

0 1 2

[0096] It should be noted that the centrifugal blower X that is useful for the present embodiment can also be incorporated into the air conditioner.

Four

Don't do that! ^.

(Fifth embodiment)

FIG. 29 shows a centrifugal blower X that can be used in the fifth embodiment of the present invention.

Five

3 2

In addition, a mixed flow centrifugal diffuser 23 is provided on the blowout side of the impeller 1 to guide the blown air flow from the impeller 1 from the obliquely rear side to the centrifugal direction. In this way, an opening 22 is formed in the outer peripheral portion of each blade 3 on the hub side, and the blowing resistance force S of the air flow blown from the blade 3 is reduced, and the air blown from the impeller 1 is reduced. It is possible to efficiently recover the static pressure of the dynamic pressure in the flow and improve the performance (that is High efficiency, low noise). Other configurations and operational effects are the same as those in the third embodiment, and thus description thereof is omitted.

Next, a modified example of the centrifugal blower X that works on the fifth embodiment will be described.

Five

(Modification I)

As shown in FIG. 30, the tip side end of each blade 3 in the impeller 1 may be inclined at substantially the same inclination angle as the inclination angle of the ring body 20. Even in this case, D

0, D 1,

The relationship between D, H, L, and B is the same as described above.

2

[Modification II]

As shown in FIG. 31, the tip side end of each blade 3 in the impeller 1 is inclined at substantially the same inclination angle as the inclination angle of the ring body 20, and the inlet side end portion of each blade 3 is connected to the hub. Try to tilt the impeller 1 so that it approaches the centripetal direction of the impeller 1 as you move to the side. Even in this case, the relationship between D, D, D, H, L, and B is the same as described above.

0 1 2

[0099] In the centrifugal blower that works in the third to fifth embodiments, the present invention is applied to one having a large number of blades 3, 3, ... (ie, 30 to 50).

Centrifugal blower X that is useful for this embodiment

Of course, 4 can also be incorporated into the air conditioner. Of course, the same effect can be obtained with a spiral casing.

[0100] (Variation III)

The centrifugal blower X in FIG. 32 is a blade of the centrifugal blower X according to the third embodiment described above.

5 3 A mixed-flow centrifugal diffuser 23 similar to that shown in FIGS. 29 to 31 is provided for the structure of the car and the bell mouth.

[0101] In this way, as shown in the figure, the wind speed distribution at the outlet of each blade 3 of the impeller 1 becomes larger on the suction port side due to the guide action of the ring body 20 described above, while on the hub 2 side relatively Becomes smaller. However, after passing through the diffuser passage in the mixed flow direction deviated to the hub 2 side, the blown air on the hub 2 side is accelerated in the mixed flow direction, and finally blown out in the centrifugal direction. Therefore, the blowout force in the centrifugal direction is blown out, and the blowout speed of the blowout flow is uniform throughout. Therefore, the air blowing efficiency is improved and the silent performance is effectively improved. [0102] In order to confirm this action, for example, the centrifugal fan X according to the modified example I of the third embodiment shown in Fig. 19 (Fig. 33) and the conventional centrifugal fan with a shroud are mixed with a centrifugal flow centrifugal separator.

Three

When compared with the wind speed distribution of each one with the diffuser 23 (Fig. 34), it is as follows.

That is, first, in the conventional centrifugal blower with shroud of FIG. 34, the air flow sucked from the air suction port 6 of the bell mouth 5 is displaced to the hub 2 side and flows to the outlet side of each blade 3. Wind velocity distribution force at 6 The air intake port 6 becomes smaller on the hub 2 side, which is smaller, and is greatly displaced on the hub 2 side.

[0104] Moreover, since the flow displaced to the hub 2 side passes through the passage in the mixed flow direction of the mixed flow centrifugal diffuser 23, the flow is further shifted to the rear and blown in the centrifugal direction as it is. The wind speed distribution of the blown air flow is greatly displaced backward.

[0105] On the other hand, the field of the centrifugal blower X according to Modification I of the third embodiment shown in FIG.

In this case, the ring body 20 is provided on the outer periphery of the tip end in the axial direction of the blade 3 as described above, and the main flow is generated by the circulating flow f formed by the ring body 20 as described above.

2

Since f is drawn toward the tip of blade 3, the wind speed at the exit of blade 3 is increased accordingly.

1

Distribution is considerably improved. On the other hand, when viewed as a whole of the air outlet where the air blown from the ring part 20 is large, it is not necessarily uniform.

On the other hand, in the case of the centrifugal blower X having the radial flow-type mixed flow centrifugal diffuser 23 in which the shape of the passage changes in the radial direction according to the modified example ΠΙ of the present embodiment,

Five

As shown in Fig. 35, the noise reduction effect is shown in Fig. 34 because the air velocity distribution of the air flow finally blown out becomes uniform throughout the whole as shown in Fig. 35. It is much larger than the conventional centrifugal blower with shroud.

[Sixth Embodiment]

FIG. 36 and FIG. 37 show an impeller of a centrifugal blower that can be used in the sixth embodiment of the present invention.

For example, as shown in FIGS. 36 and 37, the impeller 1 of this centrifugal blower includes a disk-shaped hub 2 in which the rotating shaft 4a of the motor 4 is connected to the shaft center, and the hub 2 And a plurality of blades 3 erected at predetermined intervals along the circumferential direction. [0109] Each blade 3 of the impeller 1 has an inner diameter side end 3a that is a front edge thereof inclined forward in the rotation direction, and an outer diameter side end 3b that is a rear edge is an inner diameter side end 3a. It is located behind the impeller 1 in the rotational direction M, and the camber line is regarded as a swept wing type (so-called turbofan type) convex in the rotational direction!

[0110] The number of blades 3 of the impeller 1 is set to 20 to 50, for example, and a ring body 20 having a predetermined width H in the centrifugal direction is attached to the outer periphery of the bell mouth side end. It has been. In the case of the present embodiment, the bell mouth side end portions of the ring body 20 and the blades 3 are each configured to incline toward the hub 2 according to the directional force in the centrifugal direction, as in FIG. Other configurations are basically the same as those of the above-described embodiments. Such an impeller 1 is configured in combination with a bell mouth 5 similar to those of the above-described embodiments without providing a shroud. Even if the centrifugal blower of this embodiment is used, the following beneficial effects similar to those of the above embodiments can be obtained.

That is, the presence of the ring body 20 forms a circulating flow f that is sucked into the impeller 1 again from the blowout side of the impeller 1 through the back side of the air suction port 6 in the bell mouth 5. The

Therefore, the main air flow f passing through the blade 3 is effectively drawn to the tip side of the blade 3 by the circulating flow f.

1 2

As a result, the wind speed distribution at the exit of the blades 3 is improved evenly, improving aerodynamic performance and lowering operating noise.

[0112] Since the shroud is also unnecessary, the impeller 1 can be integrally formed, the structure can be simplified, the cost can be reduced, and the mass productivity can be improved.

(Seventh embodiment)

FIG. 38 and FIG. 39 show an impeller of a centrifugal blower that is effective in the seventh embodiment of the present invention. As shown in FIGS. 38 and 39, for example, the impeller 1 of the centrifugal blower includes a disk-shaped hub 2 in which a rotating shaft 4a of a motor 4 is connected to an axial center portion, and an outer peripheral portion of the hub 2. Consists of a plurality of blades 3 standing at predetermined intervals in the circumferential direction

[0113] Each blade 3 of the impeller 1 has an inner diameter side end portion 3a that is a front edge thereof inclined forward in the rotation direction, and an outer diameter side end portion 3b that is a rear edge is an inner diameter side end portion 3a. It is located behind the impeller 1 in the rotational direction M, and the camber line is recessed in the rotational direction. Untyped).

[0114] The number of blades 3 of the impeller 1 is set to 20 to 50, for example, and a ring body 20 having a predetermined width H in the centrifugal direction is attached to the outer periphery of the bell mouth side end. It has been. In the case of the present embodiment, the bell mouth side end portions of the ring body 20 and the blades 3 are each configured to incline toward the hub 2 according to the directional force in the centrifugal direction, as in FIG. Other configurations are basically the same as those of the above-described embodiments. Such an impeller 1 is configured in combination with a bell mouth 5 similar to those of the above-described embodiments without providing a shroud. Even if the centrifugal blower of this embodiment is used, the following beneficial effects similar to those of the above embodiments can be obtained.

That is, the presence of the ring body 20 forms a circulating flow f that is sucked into the impeller 1 again from the outlet side of the impeller 1 through the back side of the air inlet 6 in the bell mouth 5. The

1 2

[0116] Since the shroud does not require a shroud, the impeller 1 can be integrally formed, the structure can be simplified, the cost can be reduced, and the mass productivity can be improved.

(Eighth embodiment)

FIG. 40 and FIG. 41 show an impeller of a centrifugal blower that can be used in the eighth embodiment of the present invention. As shown in FIGS. 40 and 41, for example, the impeller 1 of the centrifugal blower includes a disc-shaped hub 2 having a shaft 4 connected to the rotating shaft 4a of the motor 4, and an outer peripheral portion of the hub 2. It consists of a plurality of blades 3 erected at predetermined intervals along the circumferential direction.

[0117] Each blade 3 of the impeller 1 has an inner diameter side end portion 3a that is a front edge thereof inclined forward in the rotation direction, and an outer diameter side end portion 3b that is a rear edge is an inner diameter side end portion 3a. It is positioned behind the impeller 1 in the rotational direction M, and the camber line is a receding blade type (so-called turbofan type) with a straight line.

[0118] The number of blades 3 of the impeller 1 is set to a large number of, for example, 20 to 50, and a ring body having a predetermined width H in the centrifugal direction on the outer periphery of the bell mouth side end portion thereof With 20 It is installed. In the case of the present embodiment, the bell mouth side end portions of the ring body 20 and the blade 3 are configured to incline toward the hub 2 side as they are directed in the centrifugal direction, respectively, as in FIG. . Other configurations are basically the same as those of the above-described embodiments.

Even if such an impeller 1 is used in the centrifugal blower of the present embodiment configured in combination with the bell mouth 5 similar to that of each of the above embodiments without providing a shroud, The following beneficial effects can be obtained.

1 2

As a result, the wind speed distribution at the exit of the blades 3 is improved evenly, improving aerodynamic performance and lowering operating noise. Since the shroud does not require a shroud, the impeller 1 can be integrally formed, the structure can be simplified and the cost can be reduced, and the mass productivity can be improved.

[0120] Now, the outer diameter side end 3b of each blade 3 as described above is positioned behind the rotational direction M of the impeller 1 with respect to the inner diameter side end 3a, and the camber line is a receding blade having a linear shape. The maximum static pressure efficiency ratio (reference value 1.0) and the minimum specific noise level ratio (reference value level ± 0) were measured using the number of impellers as a parameter for a centrifugal fan configured using an impeller with The results are shown in the graph in Fig. 43.

[0121] The centrifugal blower used for the measurement has the impeller configuration shown in FIGS. 40 and 41. The inlet angle 0 and the outlet angle 0 of each blade 3 are 0 = 25 ° as shown in FIG. , 0 = 50 °,

1 2 1 2 And the inlet height B of the blade 3, the outlet height B, the inner diameter D of the air inlet 6 of the bell mouth 25,

1 2 0 Inner diameter D and outer diameter D of blade 3 are B = 35mm, B = 30mm, as shown in Fig. 44.

1 2 1 2

D = 130mm, D = 110mm, D = 160mm.

0 1 2

[0122] If the measurement result force in Fig. 43 is also judged, if the number of blades 3 is less than 20, the above-mentioned circulating flow f enters the inside of the blade 3 as shown by T in Fig. 44. Performance

twenty two

Deteriorates. On the other hand, if the number of blades exceeds 50, the distance P between the leading edges of the blades 3 becomes too narrow, and the performance deteriorates. [0123] On the other hand, when the number of blades 3 is 20 to 50, the static pressure efficiency ratio is high and the specific noise level ratio is kept as low as possible. be able to . That is, it can be seen that the silent performance can be effectively improved while improving the air blowing efficiency.

[0124] The same performance improvement by the number of blades can be expected in substantially the same manner in the case of the configurations of the sixth, seventh and twelfth embodiments described later.

(Ninth embodiment)

FIG. 45 and FIG. 46 show a centrifugal blower that can be used in the ninth embodiment of the present invention. For example, as shown in FIGS. 45 and 46, the impeller 1 of this centrifugal blower includes a disc-shaped hub 2 in which the rotating shaft 4a of the motor 4 is coupled to the shaft center, and a circle on the outer periphery of the hub 2. It is composed of a plurality of blades 3 erected at predetermined intervals along the circumferential direction.

[0125] Each blade 3 of the impeller 1 has an inner diameter side end portion 3a which is a leading edge thereof, which is not inclined in any direction forward or backward in the rotational direction M, and the camber line is in the radial direction. It is a radial wing type (so-called radial plate fan type) that extends in a straight line.

[0126] The number of blades 3 of the impeller 1 is set to a large number of, for example, 30 to 72, and a ring body having a predetermined width H in the centrifugal direction on the outer periphery of the bell mouth side end. 20 is attached. In the case of the present embodiment, the bell mouth side end portions of the ring body 20 and the blades 3 are configured to incline toward the hub 2 side as they are directed in the centrifugal direction, respectively, as in FIG. 44 described above. Yes. Other configurations are basically the same as those of the above-described embodiments.

Even if such an impeller 1 is used in the centrifugal blower of the present embodiment configured in combination with the bell mouth 5 similar to that of each of the above embodiments without providing a shroud, each of the above embodiments The following beneficial effects can be obtained.

Therefore, the main air flow f passing through the blade 3 is effectively pulled toward the tip of the blade 3 by the circulating flow f.

1 2

The wind speed distribution at the exit part of blade 3 is improved evenly and aerodynamics It is possible to improve performance and reduce driving noise.

[0128] Since the shroud is also unnecessary, the impeller 1 can be integrally formed, and the cost can be greatly reduced by simplifying the structure and improving mass production.

(Tenth embodiment)

FIGS. 47 and 48 show a centrifugal fan blade wheel that can be used in the tenth embodiment of the present invention. For example, as shown in FIGS. 47 and 48, the impeller 1 of this centrifugal blower includes a disk-shaped hub 2 in which the rotating shaft 4a of the motor 4 is connected to the shaft center portion, and an outer peripheral portion of the hub 2. It consists of a plurality of blades 3 erected at predetermined intervals along the circumferential direction.

[0129] Each blade 3 of the impeller 1 has an inner diameter side end portion 3a that is a leading edge thereof that is not inclined in the forward or backward direction of the rotational direction M, and the camber line is in the rotational direction M. It is a radial blade type that is slightly inclined backward (the first variation of the radial plate fan).

[0130] The number of blades 3 of the impeller 1 is set to a large number of, for example, 30 to 72, and a ring body having a predetermined width H in the centrifugal direction on the outer periphery of the bell mouth side end portion thereof 20 is attached. In the case of the present embodiment, the ring mouth side end portions of the ring body 20 and the blades 3 are formed so as to incline toward the hub 2 side in the centrifugal direction as in the case of FIG. Other configurations are basically the same as those of the above-described embodiments.

1 2

As a result, the wind speed distribution at the exit of the blades 3 is improved evenly, improving aerodynamic performance and lowering operating noise. Since no shroud is required, the impeller 1 can be integrally molded, and the simplification of the structure and the improvement of mass productivity The cost can be reduced and the mass productivity is excellent.

[0132] Now, for the centrifugal blower of the present embodiment, the maximum static pressure efficiency ratio (reference value 1.0) and the minimum specific noise level ratio (reference value level ± 0) were measured using the number of blades as a parameter. The results are shown in the graph of FIG.

[0133] The centrifugal blower used for the measurement has the impeller configuration shown in FIGS. 47 and 48, and the inlet angle 0 and the outlet angle 0 of each blade 3 are 0 = 90 ° as shown in FIG. , 0 = 75 °,

1 2 1 2 And the entrance height of the blades 3, 3 '' ', the exit height B, the air inlet 6 of the bell mouth 5

1 2

Diameter D, impeller 1 blade 3 inner diameter D, outer diameter D are B = 25mm, B = 20mm, D = 130

0 1 2 1 2 0 mm, D = 90 mm, D = 150 mm.

1 2

When the measurement result force in FIG. 50 is also judged, in the case of the present configuration, when the number of blades 3 is less than 30, the above-described circulating flow f is changed to that of blade 3 as indicated by f ′ in FIG. Deep inside

twenty two

As a result, the suction performance deteriorates. On the other hand, if the number of blades exceeds 72, the distance P between the front edge portions 3a and 3a of the blade 3 becomes too narrow, and the performance deteriorates.

[0135] On the other hand, when the number of blades 3 is 30 to 72, the static pressure efficiency ratio is high and the specific noise level ratio is sufficiently low while the problems described above are unlikely to occur. it can. In other words, it is clear that the silent performance can be effectively improved while improving the ventilation efficiency.

[0136] Similar performance improvement by the number of blades can be expected in substantially the same manner in the case of the configurations of the ninth and eleventh embodiments described below.

(Eleventh embodiment)

FIG. 51 and FIG. 52 show a centrifugal fan blade wheel that can be used in the eleventh embodiment of the present invention. For example, as shown in FIGS. 51 and 52, the impeller 1 of this centrifugal blower includes a disc-shaped hub 2 having a shaft 4 connected to a rotating shaft 4a of a motor 4, and an outer peripheral portion of the hub 2. It consists of a plurality of blades 3 erected at predetermined intervals along the circumferential direction.

[0137] Each blade 3 of the impeller 1 has an inner diameter side end portion 3a which is a front edge thereof, which is not inclined in any direction forward or backward in the rotational direction M, and the camber line is forward in the rotational direction M. It is regarded as a radial wing type (second variation of the radial plate fan) The

[0138] The number of blades 3 of the impeller 1 is set to a large number of, for example, 30 to 72 as described above, and a predetermined width H in the centrifugal direction is provided on the outer periphery of the bell mouth side end portion. A ring body 20 is provided. In the case of the present embodiment, the end portions on the bell mouth side of the ring body 20 and the blades 3 are formed so as to be inclined toward the hub 2 side in the centrifugal direction as in the case of FIG. Other configurations are basically the same as those of the above-described embodiments.

Even if such an impeller 1 is a centrifugal blower configured in combination with a bell mouth 5 similar to that of each of the above embodiments without providing a shroud, it is the same as that of each of the above embodiments. The following beneficial effects can be obtained.

1 2

[0140] Since the shroud is unnecessary, the impeller 1 can be integrally formed, and the cost can be greatly reduced by simplifying the structure and improving mass productivity.

(Twelfth embodiment)

FIG. 53 and FIG. 54 show a centrifugal fan blade wheel that can be used in the twelfth embodiment of the present invention.

As shown in FIGS. 53 and 54, for example, the impeller 1 of this centrifugal blower includes a disk-shaped hub 2 in which the rotating shaft 4a of the motor 4 is connected to the shaft center, and the hub 2 And a plurality of blades 3 erected along the circumferential direction along the circumferential direction at a predetermined interval.

[0142] Each blade 3 of the impeller 1 is of a radial blade type (radial tip fan type with an exit angle 0 of about 90 °) in which the camber line has a concave curve in the rotational direction.

2

The number of blades 3 of the impeller 1 is set to, for example, 20 to 50, as in the sixth, seventh, and eighth embodiments. A ring body 20 having a predetermined width H is attached. In the case of this embodiment, the ring body 20 Similarly to the case of FIG. 44 described above, the end portions of the blade 3 on the bell mouth side are each configured to incline toward the hub 2 side toward the centrifugal direction. Other configurations are basically the same as those of the above-described embodiments.

1 2

As a result, the wind speed distribution at the exit of the blades 3 is evenly improved, and aerodynamic performance can be improved and operation noise can be reduced.

[0144] Since the shroud is also unnecessary, the impeller 1 can be integrally formed, and the cost can be greatly reduced by simplifying the structure and improving mass productivity.

(Thirteenth embodiment)

Next, FIGS. 55 to 58 show the configuration of the main part of a centrifugal blower that is useful for the thirteenth embodiment of the present invention.

As shown in FIGS. 55 to 58, for example, the impeller 1 of this centrifugal blower is a disk-shaped hub in which the rotating shaft of the motor is connected to the shaft center portion as in the above embodiments. 2 and a plurality of blades 3 erected on the outer peripheral portion of the hub 2 along the circumferential direction at a predetermined interval.

[0146] Each blade 3 of this impeller 1 is of a forward inclined blade type 3A (Fig. 57) whose whole is inclined at a predetermined angle forward in the rotational direction M, or a reverse inclined blade type 3B ( Figure 58).

[0147] In any of these types, the number of blades 3 of the impeller 1 is set to a large number of 30 to 72, for example, on the outer periphery of the bell mouth side end. Is provided with a ring body 20 having a predetermined width H in the centrifugal direction. In the case of the present embodiment, the ring mouth side end portions of the ring body 20 and the blades 3 are formed so as to incline toward the hub 2 side in the centrifugal direction, as is apparent from FIG. Other configurations are described above. It is the same as that of each embodiment

Even if such an impeller 1 is used in the centrifugal blower of the present embodiment configured in combination with the bell mouth 5 similar to that of each of the above embodiments without providing a shroud, The following effects similar to the above can be obtained.

[0148] That is, the ring body 20 forms a circulation flow f in which the blowing side force of the impeller 1 is again sucked into the impeller 1 through the back side of the air suction port 6 in the bell mouth 5.

2

The main air flow f passing through the root 3 is attracted to the tip side of the blade 3 by the circulating flow f.

1 2

In addition, the wind speed distribution at the exit part of the blade 3 is improved, so that aerodynamic performance can be improved and the noise of operation can be reduced. In addition, since the shroud is unnecessary, the impeller 1 can be integrally formed, the structure can be simplified, the cost can be reduced, and the mass productivity can be improved.

[0149] In such a configuration, the relationship with the inner diameter D of the air suction port 6 of the bell mouth 5 is further increased.

0

It produces unique effects such as

(A) When blade 3 is forward tilted blade 3A

In this case, for example, as shown in FIG. 57, the circulating flow f f in which the blade 3 (3A) is formed by the ring body 20

It acts in the direction of sucking 2 and a strong circulating flow 2 is formed.

[0150] Further, as indicated by reference numeral 6A in FIG. 55, the inner diameter D of the air suction port 6 of the bell mouth 5 is increased.

0 Even when cracked, the strong circulating flow f does not penetrate deeply into the blade 3 (3A)

2

Circulates smoothly around body 20. As a result, good blowing performance can be realized.

[0151] (B) When blade 3 is backward tilted blade 3B

In this case, for example, as shown in FIG. 58, the blade 3 (3B) acts in a direction in which it is difficult to suck the circulating flow f formed by the ring body 20. In addition, as indicated by reference numeral 6B in FIG.

2

Even if the inner diameter D of the air inlet 6 of the bell mouth 5 is reduced, the circulating flow f is

0 2 It does not penetrate deeply into the root 3 (3B) and circulates smoothly around the ring body 20. As a result, good air blowing performance can be achieved.

[0152] (Fourteenth embodiment)

Next, FIG. 59 and FIG. 60 show a centrifugal blower useful for the fourteenth embodiment of the present invention. The structure of the main part of the is shown.

[0153] As shown in FIGS. 59 and 60, for example, the impeller 1 of this centrifugal blower is a disc-shaped hub in which the rotating shaft of the motor is connected to the shaft center as in the above embodiments. 2 and a plurality of blades 3 erected on the outer peripheral portion of the hub 2 along the circumferential direction at a predetermined interval.

[0154] Each blade 3 of the impeller 1 has a forward-tilt type 3A in which only its blade tip 3C is inclined at a predetermined angle forward in the rotational direction M, or a reverse-tilt type 3B of the opposite side. (Folding line L).

[0155] In any of these types, the number of blades 3 of the impeller 1 is set to a large number of 30 to 72, for example, on the outer periphery of the bell mouth side end. Is provided with a ring body 20 having a predetermined width H in the centrifugal direction. In the case of the present embodiment, the ring mouth side end portions of the ring body 20 and the blades 3 are formed so as to incline toward the hub 2 side toward the centrifugal direction, as is apparent from FIG. Other configurations are basically the same as those of the above-described embodiments.

Even if such an impeller 1 is a centrifugal blower configured in combination with the bell mouth 5 similar to that of each of the above embodiments as shown in FIG. The following effects can be obtained.

[0156] That is, the ring body 20 forms a circulating flow f in which the blowing side force of the impeller 1 is again sucked into the impeller 1 through the back side of the air suction port 6 in the bell mouth 5.

2

1 2

, Improved wind speed distribution at the exit of blade 3, and improved aerodynamic performance

Driving noise can be reduced. Since the shroud does not require a shroud, the impeller 1 can be integrally formed, the structure can be simplified and the cost can be reduced, and the mass productivity can be improved.

[0157] In such a configuration, the relationship with the inner diameter D of the air suction port 6 of the bell mouth 5

0

It produces unique effects such as

(A) In the case of the forward inclined blade 3A in which the blade tip 3C of the blade 3 is inclined forward in the rotation direction In this case, for example, as shown in FIG. 60, the blade 3 (3A) is formed by the ring body 20. Circulating flow f

A relatively strong circulating flow acting in the direction of sucking in 2 f

2 is formed.

[0158] Further, as indicated by reference numeral 6A in Fig. 59, the inner diameter D of the air suction port 6 of the bell mouth 5 is increased.

0 Even when cracked, the relatively strong circulating flow f does not penetrate deeply into the blade 3 (3A).

2

Cycles smoothly around the ring body 20. As a result, good blowing performance can be achieved.

[0159] (B) In case of blade 3B with blade 3 blade tip 3C inclined backward in the rotation direction

In this case, as shown in FIG. 60, for example, the circulation flow f in which the blade 3 (3B) is formed by the ring body 20

Acts in a direction that makes it difficult to inhale 2.

[0160] Further, as indicated by reference numeral 6B in Fig. 59, the inner diameter D of the air suction port 6 of the bell mouth 5 is reduced.

Even when 0, the strong circulating flow f does not penetrate deeply into the blade 3 (3B).

2

Circulates smoothly around body 20. As a result, it is possible to achieve good air blowing performance.

Claims

The scope of the claims

[1] A hub (2) to which the rotating shaft (4a) of the motor (4) is connected to the shaft center portion, and an outer peripheral portion of the hub (2) are erected at predetermined intervals along the circumferential direction, The front edge (3a) is provided with an impeller (1) composed of a plurality of blades (3) inclined forward in the rotational direction, and an air suction port (6) is provided on the air suction side of the impeller (1). ) Having a bell mouth (5) having a blower side force of the impeller (1) passing through the back side of the air inlet (6) in the bell mouth (5) Circulating flow (f) sucked into the impeller (1) again

A centrifugal blower characterized by being configured to be capable of forming two.

[2] A hub (2) to which the rotating shaft (4a) of the motor (4) is coupled to the shaft center part, and an outer peripheral part of the hub (2) are erected at predetermined intervals along the circumferential direction, The front edge (3a) has an impeller (1) composed of a plurality of blades (3), even if the front edge (3a) is inclined in any direction in the rotational direction forward and the rotational direction rearward. A centrifugal blower in which a bell mouth (5) having an air suction port (6) is disposed on the air suction side of 1), wherein the bell mouth (5) is connected to the bell mouth (5) from the blow side of the impeller (1). A centrifugal blower configured to form a circulating flow (f) sucked into the impeller (1) again through the back side of the air suction port (6).

2

3. The centrifugal blower according to claim 2, wherein the entire blade (3) of the impeller (1) is inclined along the rotation direction.

4. The centrifugal fan according to claim 2, wherein the entire blade (3) of the impeller (1) is inclined to the opposite side to the rotation direction.

5. The centrifugal blower according to any one of claims 1 and 2, wherein a blade tip of the blade (3) in the impeller (1) is inclined along a rotation direction.

[6] The centrifugal blower according to any one of claims 1 and 2, wherein a blade tip of the blade (3) in the impeller (1) is inclined to a side opposite to a rotation direction. .

[7] The inner diameter of the air inlet (6) in the bell mouth (5) is D, and the impeller (1)

0

When the inner diameter of the blade (3) is D and the outer diameter of the blade (3) is D,

1 2

The present invention is characterized in that 0 <(D -D) / (D -D) <0.6 is set.

0 1 2 1

6. Centrifugal blower according to one of the above.

[8] The inner diameter of the air inlet (6) in the bell mouth (5) is D, and the impeller (1) When the inner diameter of the blade (3) is D and the outer diameter of the blade (3) is D,

1 2

-0. 3 <(D -D) / (D -D) <0.3

0 1 2 1

The centrifugal blower according to any one of 1 to 6.

[9] The ring body (9), (20) having a predetermined width in the centrifugal direction is attached to the tip end in the axial direction of the blade (3) in the impeller (1). The centrifugal blower according to any one of 1 to 8.

[10] When the centrifugal width of the ring body (20) is H and the outer diameter of the blade (3) of the impeller (1) is D, 0.05 <ki = H / D <0.225 A feature characterized by

twenty two

The centrifugal blower according to claim 9.

[11] The mixed flow diffuser (23) is provided on the blowout side of the impeller (1) for drafting the airflow blown from the impeller (1) obliquely rearward. The centrifugal blower according to any one of 1 to 10.

[12] The mixed flow and centrifugal diffuser (23) for guiding the blown air flow from the impeller (1) in the centrifugal direction obliquely from the rear side are provided on the blowout side of the impeller (1). The centrifugal blower according to any one of claims 1 to 10, wherein:

[13] The circulating flow (f) passes through the outer periphery of the air suction port (6) in the bell mouth (5).

The centrifugal blower according to any one of claims 1 to 12, wherein a circulation space (S) that can be passed is formed.

[14] The outlet side height of each blade (3) in the impeller (1) is B, and the outer diameter of the blade (3) is D.

2, BZD≥0.113 is set.

2

The centrifugal blower described in the item.

[15] The outer diameter D of the hub (2) constituting the impeller (1) is smaller than the outer diameter D of each blade (3).

The centrifugal blower according to any one of claims 1 to 13, characterized by being set to 3 2.

[16] The outlet height of each blade (3) in the impeller (1) is B, and the outer diameter of the blade (3) is D.

16. The centrifugal fan according to claim 15, wherein B / D≥0.08 is set.

2

[17] The centrifugal blower according to any one of claims 1 to 16, wherein the number of blades (3) in the impeller (1) is 15 as many as 5 blades.

[18] The number of blades (3) in the impeller (1) is 20 to 50 The centrifugal blower according to any one of claims 1 to 16.

[19] The centrifugal blower according to any one of [2] to [16], wherein the number of blades (3) in the impeller (1) is 30 to 72.

[20] An air conditioner in which a heat exchange (15) and a blower (X) are arranged in a ventilation path (14) formed in a casing (13), and the blower (X) An air conditioner using the centrifugal blower according to any one of claims 1 to 19.