KR100824149B1 - Centrifugal blower and air conditioner with centrifugal blower - Google Patents

Abstract

The hub 2 to which the rotating shaft 4a of the motor 4 is connected to the shaft center part, and the outer periphery part of the hub 2 are installed at predetermined intervals along the circumferential direction, and the leading edge 3a faces forward in the rotation direction A centrifugal blower is provided, which includes an impeller 1 made up of a plurality of inclined blades 3, and a bell mouse 5 having an air inlet 6 on the air intake side of the impeller 1. From the ejection side of the impeller 1, the circulating flow f ₂ which passes through the back side of the air suction port 6 in the bell mouse 5 and inhales into the said impeller 1 again is formed.

Description

CENTRIFUGAL BLOWER AND AIR CONDITIONER WITH CENTRIFUGAL BLOWER}

The present invention relates to an air conditioner having a centrifugal blower and a centrifugal blower.

Generally known centrifugal blowers include a hub connected to a rotating shaft of a motor, a shroud disposed to face the outer peripheral portion of the hub at predetermined intervals, and a predetermined interval along the circumferential direction between the shroud and the outer peripheral portion of the hub. There is a thing provided with the impeller which consists of several blade arrange | positioned and arrange | positioned (refer patent document 1).

Further, the centrifugal blower having no shroud includes an impeller comprising a hub to which a rotating shaft of a motor is connected to the shaft center portion, and an impeller composed of a plurality of blades inserted at predetermined intervals along the circumferential direction at the outer peripheral portion of the hub. The bell mouth which has an air intake port in the air intake side of the thing may be comprised (refer patent document 2).

[Patent Document 1: Japanese Patent Application Laid-Open No. 11-101194]

[Patent Document 2: Japanese Unexamined Patent Publication No. Hei 10-185238]

By the way, in the case of the centrifugal blower disclosed by patent document 1, the outer diameter side edge part of a blade is used abundantly as a retreating vane type centrifugal blower (namely, a turbo fan) located behind the rotation direction of an impeller rather than an inner diameter side part, and is shroud And a complex structure in which a plurality of blades are arranged between the outer peripheral portion of the hub and the hub. Therefore, in manufacturing the impeller, it is necessary to join the shroud manufactured separately to the one in which the hub and the blade are integrally formed, which causes problems in mass productivity and cost.

On the other hand, in the case of the centrifugal blower disclosed in Patent Literature 2, the outer diameter side end portion of the blade is widely used as a forward vane type centrifugal blower (that is, a sirocco fan) positioned at the front of the impeller rotation direction rather than the inner diameter side end portion, Has a simple structure. However, if the vortex casing is not provided, the aerodynamic performance and the driving sound characteristics deteriorate, which causes problems in terms of mass productivity and cost.

This invention is made | formed in view of the said point, Comprising: It aims at providing the centrifugal blower which is excellent in mass productivity, cost reduction is possible, low noise, and high efficiency, and the air conditioner provided with the centrifugal blower.

In the present invention, as a first aspect for solving the above problems, a hub (2) to which a rotating shaft (4a) of a motor (4) is connected to an axis center portion, and a predetermined interval along a circumferential direction at an outer peripheral portion of the hub (2) And an impeller 1 composed of a plurality of blades 3 whose leading edges 3a are inclined toward the front in the rotational direction, and an air inlet 6 is provided on the air intake side of the impeller 1. A centrifugal blower formed by arranging a bell mouth (5) having a suction, passing through the back side of the air inlet (6) in the bell mouse (5) from the ejecting side of the impeller (1) and again suctioning the impeller (1). that is configured to form a circulating flow (f _2).

In this way, in the impeller 1 provided with the blade | blade of a retracting wing shape represented by the turbofan, for example, the back surface of the air intake port 6 in the bell mouse 5 from the extraction side of the said impeller 1 is carried out. The circulation flow f ₂ which passes through the side and is sucked into the impeller 1 again is formed.

As a result, the air mainstream f ₁ passing through the blade 3 is attracted to the tip side of the blade 3 by the circulation flow f ₂ , and the wind speed distribution at the outlet portion of the blade 3 is improved. As a result, aerodynamic performance can be improved and driving noise can be reduced.

In addition, since the shroud is unnecessary, the integral molding of the impeller 1 can be performed, the cost can be reduced, and the mass productivity is excellent.

In the present invention, as a second aspect for solving the above problems, a plurality of hubs 2 to which the rotating shaft 4a of the motor 4 is connected to the shaft center portion and a plurality of the outer peripheral portions of the hub 2 at predetermined intervals in the circumferential direction are provided. There is an impeller 1 made up of the blade 3, which is installed in the front edge 3a, which does not incline even when the leading edge 3a faces in the rotational direction forward and the rearward direction of the rotational direction, and on the air suction side of the impeller 1 A centrifugal blower formed by arranging a bell mouth (5) having an inlet (6), passing through the back side of the air inlet (6) in the bell mouse (5) from the ejecting side of the impeller (1) again. and it is configured to form a circulating flow (f ₂₎ to be drawn into the (1).

By such a configuration, also in the impeller 1 provided with the blade represented by a radial plate fan, for example, the back side of the air inlet 6 at the bell mouse 5 is removed from the ejection side of the impeller 1. The circulation flow f ₂ which passes through and is again sucked into the impeller 1 is formed.

As a result, the air main stream f ₁ passing through each blade 3 is attracted to the tip side of each blade 3 by the circulation flow f ₂ , and the wind speed distribution at the outlet portion of each blade 3 is obtained. It is possible to improve the aerodynamic performance and to reduce the noise of the driving sound.

In addition, since the shroud is unnecessary, the integral molding of the impeller 1 can be performed, the cost can be reduced, and the mass productivity is excellent.

It is required that the entire blade 3 in the impeller 1 be inclined along the rotational direction.

According to this structure, each blade 3 acts in the direction to suck the circulation flow f ₂ formed by the ring body 20, and strong circulation flow f ₂ is formed.

In addition, even when the inner diameter of the air intake port 6 of the bell mouse 5 is enlarged, the above strong circulation flow f ₂ does not go deeply into the inside of each blade 3, but smoothly in the vicinity of the ring body 20. Circulate As a result, better blowing performance can be realized.

It is also possible to incline the whole blade 3 in the impeller 1 in the opposite direction of rotation, that is, in the opposite side to the direction of rotation.

With such a configuration, acts as difficult to suck the circulation flow (f _2), the blade (3) is formed by a ring body (20) direction.

In addition, even when the inner diameter of the air inlet 6 of the bell mouse 5 is made small, the strong circulation flow f ₂ does not go deeply to the inside of the blade 3, but circulates smoothly in the vicinity of the ring body 20. . As a result, good blowing performance can also be realized.

It is also possible to incline the tip of the blade 3 in the impeller 1 along the rotational direction.

According to this structure, the blade 3 acts in the direction to suck the circulation flow f ₂ formed by the ring body 20, and a strong circulation flow f ₂ is formed.

In addition, even when the inner diameter of the air intake port 6 of the bell mouse 5 is increased, the strong circulation flow f ₂ does not enter the inner side of the blade 3 deeply and circulates smoothly in the vicinity of the ring body 20. . As a result, better blowing performance can be realized.

It is also possible to incline the tip of the blade 3 in the impeller 1 to the side opposite to the rotational direction.

With such a configuration, functions as each blade 3 is difficult to suck the circulation flow (f ₂₎ is formed by a ring body (20) direction.

Further, even when the inner diameter of the air intake port 6 of the bell mouse 5 is made small, the strong circulation flow f ₂ does not go deeply into the inside of each blade 3, but circulates smoothly in the vicinity of the ring body 20. do. As a result, good blowing performance can also be realized.

In addition, the inner diameter of the air inlet 6 at the bell mouse 5 is D ₀ , the inner diameter of the blade 3 at the impeller 1 is D ₁ , and the outer diameter of the blade 3 is D ₂ . At this time, 0 <(D ₀ -D ₁ ) / (D ₂ -D ₁ ) <0.6 may be set.

In such a configuration, when the number of blades 3 is small (e.g., 5 to 15 sheets), as shown in FIG. 4, the lowest non-noise Ks can be suppressed to a low level. In addition, the aerodynamic performance can be improved and the driving noise can be reduced.

On the other hand, when (D ₀ -D ₁ ) / (D ₂ -D ₁ ) ≥ 0.6, when the number of blades 3 is small, as shown in FIG. 5B, the leading edge end of the blade 3 is shown. The reverse flow f 'generated at the same time becomes strong, and the circulation flow f ₂ at the trailing edge of the blade 3 is weakened, which hinders the improvement of aerodynamic performance.

When 0≥ (D ₀ -D ₁ ) / (D ₂ -D ₁ ), when the number of blades 3 is small, as shown in FIG. 5 (a), the leading edge of the blade 3 is shown. The tip portion cannot work effectively, which hinders the improvement of aerodynamic performance.

In addition, the inner diameter of the air inlet 6 at the bell mouse 5 is D ₀ , the inner diameter of the blade 3 at the impeller 1 is D ₁ , and the outer diameter of the blades 3, 3. When D ₂ is set, it may be set to be -0.3 <(D ₀ -D ₁ ) / (D ₂ -D ₁ ) <0.3.

In such a configuration, when the number of blades 3 is large (e.g., 30 to 50), as shown in FIG. 14, the lowest non-noise Ks can be suppressed to a low level. In addition, the aerodynamic performance can be improved and the driving noise can be reduced.

On the other hand, when (D ₀ -D ₁ ) / (D ₂ -D ₁ ) ≥ 0.3, when the number of blades 3 is large, the reverse flow generated at the leading edge of the blade 3 becomes strong, and the blades The circulation flow f ₂ at the trailing edge of (3) is weakened, which hinders the improvement of aerodynamic performance.

Further, when -0.3≥ (D ₀ -D ₁ ) / (D ₂ -D ₁ ), when the number of blades 3 is large, the leading edge of the blades 3 cannot effectively act and thus aerodynamic performance. Inhibits improvement.

In addition, the ring bodies 9 and 20 having a predetermined width in the centrifugal direction may be provided in the axial distal end portion of the blade 3 in the impeller 1. In such a configuration, the ring bodies 9 and 20 idling with the impeller 1 act as rotating disks, and the flow in the rotational direction is induced in the outlet flow of the blades 3 by the viscous action of the rotating disks. The fan performance can be improved and the silence can be achieved by rectifying the blowout flow and rectifying the circulation flow.

When the centrifugal width of the ring body 20 is set to H and the outer diameter of the blade 3 in the impeller 1 is set to D ₂ , it may be set to be 0.05 <ki = H / D ₂ <0.225. In such a configuration, as shown in FIG. 9, the lowest non-noise Ks can be suppressed to be low, and further aerodynamic performance can be further improved and driving noise can be reduced.

However, it is more preferable for the low noise domoham that when the 0.1≤ki = H / D ₂ ≤0.15.

On the other hand, if the ki = H / D ₂ ≤0.05 effect is small, when the ki = H / D ₂ ≥O.225 is granted an adverse effect on the formation of circulating flow, the circulating flow from the trailing edge of the leading end of the blade (3) weak It hinders the improvement of aerodynamic performance.

On the ejection side of the impeller 1, an inclined flow diffuser 23 for guiding the ejected air flow from the impeller 1 to the rear side may be provided. In such a configuration, the static pressure recovery of the dynamic pressure in the air flow taken out from the impeller 1 can be efficiently performed, which greatly contributes to the performance improvement (that is, high efficiency and low noise).

Incidentally, an inclined flow centrifugal diffuser 23 for guiding the take-off air flow from the impeller 1 from the rear side in a centrifugal direction may be provided on the takeout side of the impeller 1. In such a configuration, the recovery of the static pressure of the dynamic pressure in the air flow blown out from the impeller 1 and the uniformity of the wind speed distribution of the blown out wind are efficiently performed, which greatly contributes to the performance improvement (that is, high efficiency and low noise).

On the outer circumferential side of the air inlet 6 in the bell mouse 5, a circulation space S through which the circulation flow f ₂ can pass may be formed, and in such a case, the circulation flow f ₂ is formed. This becomes easy and certain.

When the outer diameter of each blade (3) to the outlet height B, of the blade 3 in the impeller (1) hayeoteul to D _2, may be set to the B / D ₂ ≥0.113. In such a configuration, the problem that the streamline f ₂ of the air flow on the outlet side of the impeller 1 is shaken is solved, and stable performance is obtained.

On the other hand, when B / D ₂ <0.113, as the air volume increases, the streamline f ₁ of the air flow at the outlet side of the impeller ₁ is greatly shaken, and eventually the circulation flow f ₂ is formed between the blades 3. Clogging the flow path, the performance suddenly drops.

It is also possible to set the outer diameter of the hub (2) constituting the impeller (1), smaller than the outer diameter (D ₂₎ of each blade (3). In such a configuration, the opening 22 is formed in the outer peripheral portion of the hub side in each blade 3, and in particular, in the case where the above-described inclined flow diffuser 23 or the inclined flow centrifugal diffuser 23 is provided, the blade 3 The blowout resistance of the air flow blown out from () decreases.

When the exit height of each blade 3 in the impeller 1 is B and the outer diameter of the blade 3 is D ₂ , B / D ₂ ≥0.08 may be set. In such a configuration, even if the exit height B of each blade 3 in the impeller 1 becomes small, the problem that the streamline f ₁ of the air flow on the exit side of the impeller ₁ is shaken is solved and the stable performance is achieved. Is obtained.

On the other hand, when B / D ₂ <0.08, the streamline f ₁ of the air flow on the outlet side of the impeller 1 is greatly shaken, and eventually the circulation flow f ₂ flows between the blades 3. By blocking the performance suddenly drops.

In addition, the number of the blades 3, 3... In the impeller 1 is preferably 5 to 15 sheets. In this case, according to the present invention, as shown in Fig. 4, even when the number of blades 3 is small, the lowest non-noise Ks can be suppressed low, effectively improving aerodynamic performance and lowering noise of driving. Can be planned.

The number of blades 3 in the impeller 1 may be set to 20 to 50 sheets. For example, as shown in Figs. 14 and 43, when the number of blades 3 is large, the highest static pressure efficiency ratio can be increased, while the lowest non-noise level can be suppressed low, and more efficiently. The aerodynamic performance can be improved and the driving noise can be reduced.

The number of blades 3 in the impeller 1 is preferably 30 to 72 sheets.

As shown in Figs. 14 and 50, when the number of blades 3 is about 30 to 72, the maximum static pressure efficiency ratio can be effectively increased, while the lowest non-noise level is as low as possible. It can suppress, and can improve aerodynamic performance more efficiently and reduce noise of a driving sound more efficiently.

Moreover, in the air conditioner which arrange | positioned the heat exchanger 15 and the blower X in the ventilation path 14 formed in the casing 13, as said blower X, the centrifugal blower of the said aspect is employ | adopted. It may be. In such a configuration, since the effective action effect possessed by the centrifugal blower can be exerted, it contributes greatly to the performance improvement and cost reduction as an air conditioner.

1 is a longitudinal cross-sectional view of a centrifugal blower X ₁ according to a first embodiment of the present invention.

2 is a front view of the impeller in the centrifugal blower X ₁ according to the first embodiment.

3A, 3B and 3C are sectional views showing the principal parts of three modifications of the centrifugal blower X ₁ according to the first embodiment.

Fig. 4 is a characteristic diagram showing the change in the lowest specific noise (Ks) for the variable k = (D ₀ -D ₁ ) / (D ₁ -D ₁ ) in the centrifugal blower (X ₁ ) according to the first embodiment. to be.

FIG. 5A is a sectional view showing the main parts of the case of k ≦ 0, and 5b is a sectional view of the main part of the case of k ≧ 0.6.

6 is a longitudinal sectional view of the air conditioner Z ₁ incorporating the centrifugal blower X ₁ according to the first embodiment.

7 is a longitudinal cross-sectional view of the centrifugal blower X ₂ according to the second embodiment.

8A to 8L are cross-sectional views showing the main parts of a modification of the centrifugal blower X ₂ according to the second embodiment of the present invention.

FIG. 9 is a characteristic diagram showing a change in the lowest specific noise (Ks) for the variable ki = H / D ₂ in the centrifugal blower (X ₂ ) according to the second embodiment.

FIG. 10 is a characteristic diagram showing a change in the lowest specific noise (Ks) for the variable L / D ₂ in the centrifugal blower X ₂ according to the second embodiment.

Figure 11 is a longitudinal sectional view of an air conditioner (Z ₂₎ built-in the centrifugal blower (X ₂₎ in the second embodiment.

12 is a longitudinal cross-sectional view of the centrifugal blower X ₃ according to the third embodiment.

13 is a front view of the impeller in the centrifugal blower X ₃ according to the third embodiment.

FIG. 14 is a characteristic diagram showing the change in the lowest specific noise (Ks) for the variable k = (D ₀ -D ₁ ) / (D ₂ -D ₁ ) in the centrifugal blower (X ₃ ) according to the third embodiment. to be.

FIG. 15 is a characteristic diagram showing a change in maximum specific noise (Ks) for L / D ₂ in the centrifugal blower (X ₃ ) according to the third embodiment.

FIG. 16 is a characteristic diagram showing a change in the static pressure with respect to the air volume in the centrifugal blower X ₃ according to the third embodiment.

FIG. 17 is a characteristic diagram showing a change in the maximum flow rate coefficient? Max (where no deterioration is set as reference value = 1) with respect to B / D ₂ in the centrifugal blower X ₃ according to the third embodiment.

Figure 18 is a longitudinal sectional view of an air conditioner (Z ₃₎ built in the centrifugal blower (X ₃₎ according to the third embodiment.

19 is a half longitudinal cross-sectional view showing a modification I of the centrifugal blower X ₃ according to the third embodiment.

20 is a half longitudinal cross-sectional view showing a modification II of the centrifugal blower X ₃ according to the third embodiment.

21 is a half longitudinal cross-sectional view showing a modification III of the centrifugal blower X ₃ according to the third embodiment.

22 is a half longitudinal cross-sectional view of the centrifugal blower X ₄ according to the fourth embodiment.

FIG. 23 is a characteristic diagram showing a change in the maximum flow rate coefficient Φ max (the reference value is 1 when no deterioration is) with respect to B / D ₂ in the centrifugal blower X ₃ according to the fourth embodiment.

24 is a half longitudinal cross-sectional view showing a modification I of the centrifugal blower X ₄ according to the fourth embodiment.

25 is a half longitudinal cross-sectional view showing a modification II of the centrifugal blower X ₄ according to the fourth embodiment.

26 is a half longitudinal cross-sectional view showing a modification III of the centrifugal blower X ₄ according to the fourth embodiment.

27 is a half longitudinal cross-sectional view showing a modification IV of the centrifugal blower X ₄ according to the fourth embodiment.

FIG. 28 is a half longitudinal cross-sectional view showing a modification V of the centrifugal blower X ₄ according to the fourth embodiment.

29 is a half longitudinal cross-sectional view of the centrifugal blower X ₅ according to the fifth embodiment.

30 is a half longitudinal cross-sectional view showing a modification I of the centrifugal blower X ₅ according to the fifth embodiment.

FIG. 31 is a half longitudinal cross-sectional view showing a modification II of the centrifugal blower X ₅ according to the fifth embodiment.

FIG. 32 is a half longitudinal cross-sectional view showing a configuration of Modification Example III of the centrifugal blower X ₅ according to the fifth embodiment.

FIG. 33 is a half longitudinal cross-sectional view showing the configuration and operation of a comparative example (corresponding to FIG. 19) of the centrifugal blower X ₅ according to the fifth embodiment, compared with the modified example III.

FIG. 34 is a half longitudinal cross-sectional view showing the configuration of a conventional centrifugal blower with a shroud which is another comparative example of Modification III of the centrifugal blower X ₅ according to the fifth embodiment.

35 is a graph showing the noise reduction effect of the modified example III of the centrifugal blower X ₅ according to the fifth embodiment in comparison with the comparative example.

36 is a horizontal sectional view showing the configuration of a centrifugal blower according to a sixth embodiment.

FIG. 37 is a longitudinal sectional view showing the configuration of a centrifugal blower according to a sixth embodiment. FIG.

38 is a horizontal cross-sectional view showing a configuration of a centrifugal blower according to a seventh embodiment.

FIG. 39 is a longitudinal sectional view showing the configuration of a centrifugal blower according to a seventh embodiment.

40 is a horizontal sectional view showing a configuration of a centrifugal blower according to an eighth embodiment.

FIG. 41 is a longitudinal sectional view showing the configuration of a centrifugal blower according to an eighth embodiment. FIG.

FIG. 42 is a horizontal sectional view showing a structure of a principal part of a disclosure example of a centrifugal blower according to an eighth embodiment. FIG.

43 is a graph showing the relationship between the number of blades and the performance of the test example of the centrifugal blower according to the eighth embodiment.

FIG. 44 is a half longitudinal cross-sectional view showing a configuration example of a centrifugal blower according to an eighth embodiment.

45 is a horizontal cross-sectional view showing a configuration of a centrifugal blower according to a ninth embodiment.

It is a longitudinal cross-sectional view which shows the structure of the centrifugal blower which concerns on 9th Embodiment.

FIG. 47 is a horizontal sectional view showing the configuration of a centrifugal blower according to a tenth embodiment. FIG.

48 is a longitudinal sectional view showing the configuration of a centrifugal blower according to a tenth embodiment.

FIG. 49 is a horizontal sectional view showing the structure of a principal part of a disclosure example of a centrifugal blower according to a tenth embodiment. FIG.

It is a graph which shows the performance of the test example of the centrifugal blower which concerns on 10th Embodiment in relationship with the number of blades.

FIG. 51 is a horizontal sectional view showing the configuration of a centrifugal blower according to an eleventh embodiment. FIG.

52 is a longitudinal cross-sectional view showing a configuration of a centrifugal blower according to an eleventh embodiment.

FIG. 53 is a horizontal sectional view showing the configuration of a centrifugal blower according to a twelfth embodiment. FIG.

54 is a longitudinal sectional view showing the configuration of a centrifugal blower according to a twelfth embodiment.

Fig. 55 is a half longitudinal sectional view showing the structure of a centrifugal blower according to a thirteenth embodiment.

Fig. 56 is a half longitudinal sectional view showing the structure of the main parts of the centrifugal blower according to the thirteenth embodiment.

FIG. 57 is a horizontal cross-sectional view showing the structure and operation of main parts of the centrifugal blower according to the thirteenth embodiment. FIG.

Fig. 58 is a horizontal cross sectional view showing the structure and operation of main parts of the centrifugal blower according to the thirteenth embodiment.

Fig. 59 is a half longitudinal sectional view showing the structure of a centrifugal blower according to a fourteenth embodiment.

FIG. 60 is a horizontal sectional view showing a structure and an operation of the main parts of the centrifugal blower according to the fourteenth embodiment. FIG.

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

(1st embodiment)

1 to 6 show a centrifugal blower X ₁ and an air conditioner Z ₁ according to a first embodiment of the present invention.

As shown in Figs. 1 and 2, the centrifugal blower X ₁ has a disc-shaped hub 2 to which the rotary shaft 4a of the motor 4 is connected to the shaft center portion, and an outer peripheral portion of the hub 2. In the circumferential direction is provided with an impeller (1) consisting of a plurality of blades (3) placed at a predetermined interval in the circumferential direction, the bell mouse (5) having an air inlet (6) on the air intake side of the impeller (1) It is arranged.

As shown in Fig. 2, the impeller 1 is inclined toward the front in the rotational direction, and the outer diameter side end portion 3b of each blade 3 is positioned more than the inner diameter side end portion 3a of the impeller 1. The retracting blade type (ie, turbo fan type) located at the rear side of the rotation direction M is provided. In this case, since the ratio of the static pressure rise to the total pressure rise of the impeller 1 is large, the vortex scroll is unnecessary.

Moreover, the recessed part 2a for accommodating the said motor 4 is formed in the axial center part of the said hub 2. The motor fixing part 7 fixes the motor 4. The bearing boss 8 pivotally supports the rotating shaft 4a of the motor 4. The reinforcing ring 9 connects the axial tip of each blade 3.

The inner diameter D ₀ of the air suction port 6 in the bell mouse 5 is set larger than the inner diameter D ₁ of the blade 3 in the impeller 1. Moreover, the circulation space S is formed in the back side (in other words, the outer peripheral side) of the said bell mouse 5, The air intake port in the said bell mouse 5 from the ejecting side of the impeller 1 the circulating flow (f ₂₎ is again sucked into the impeller 1 through the rear side of the 6), and is easily and configured to be surely formed.

By the way, the shape of the air inlet 6 in the bell mouse 5 may be a straight shape as shown in Fig. 3A, may be a wedge shape as shown in Fig. 3B, and is shown in Fig. 3C. As described above, the shape may be flared.

In the present embodiment, the inner diameter of the air inlet 6 at the bell mouse 5 is D ₀ , the inner diameter of the blade 3 at the impeller 1 is D ₁ , and the outer diameter of the blade 3 is represented. When D ₂ is set, it is set such that 0 <(D ₀ -D ₁ ) / (D ₂ -D ₁ ) <0.6. On the other hand, the number of blades 3 is 10 pieces.

In the centrifugal blower comprised as mentioned above, the following effect is acquired. That is, in the said structure, centering around the reinforcement ring 9, the impeller 1 is again passed through the back side of the air intake port 6 in the bell mouse 5 from the ejection side of the impeller 1 to the outer periphery. A circulating flow f ₂ sucked into is formed. Therefore, the air mainstream f ₁ passing through the blade 3 after being sucked from the air inlet 6 is drawn to the tip side of the blade 3 by the circulation flow f ₂ , and the The wind speed distribution at the exit can be improved to improve aerodynamic performance and reduce noise. In addition, since the shroud is unnecessary, the integral molding of the impeller 1 can be performed, the cost can be reduced, and the mass productivity is excellent.

In addition, in this embodiment, the inner diameter of the air intake port 6 in the bell mouse 5 is D ₀ , and the inner diameter of the blade 3 in the impeller 1 is D ₁ of the blade 3. When the outer diameter is set to D ₂ , 0 <k = (D ₀ -D ₁ ) / (D ₂ -D ₁ ) <0.6 is set. In this way, as shown in FIG. 4, the minimum non-noise Ks can be suppressed low, and further aerodynamic performance can be improved and operation noise can be reduced.

On the other hand, when 0≥k = (D ₀ -D ₁ ) / (D ₂ -D ₁ ), as shown in FIG. 5A, the leading edge of the blade 3 cannot effectively act, and aerodynamic performance Inhibits improvement. When k = (D ₀ -D ₁ ) / (D ₂ -D ₁ ) ≥0.6, as shown in FIG. 5B, the reverse flow f 'generated at the leading edge of the blade 3 becomes stronger. At the same time, the circulation flow f ₂ at the trailing end of the blade 3 is weakened to hinder the improvement of aerodynamic performance.

Incidentally, the inner diameter of the blade 3 in the centrifugal blower X ₁ according to the present embodiment is D ₁ , the outer diameter of the blade 3 is D ₂ , and the inner diameter of the air inlet 6 is D ₀ , The microphone 12 is installed at a position 1 m 45 degrees forward from the suction side center Q of the suction port 6, and the minimum value is set as k = (D ₀ -D ₁ ) / (D ₂ -D ₁ ) as a variable. When the change of the specific noise Ks was examined, the result shown in FIG. 4 was obtained. According to the said result, it turns out that favorable driving sound characteristic is acquired in the range of 0 <k <0.6.

Figure 6, the blower of a ceiling embedded type air conditioner assembly to (X ₁₎ (Z ₁₎ of the present embodiment is shown.

In this case, the heat exchanger 15 and the centrifugal blower X ₁ are arranged in the ventilation path 14 of the air flow W formed in the casing 13, and the motor fixing part 7 for fixing the motor 4 is provided. ) Is integrated with the top plate 13a of the casing 13. The air conditioner Z ₁ includes a suction grill 16, an air filter 17, a drain pan 18, and an air blower outlet 19.

In this way, because it can exert an effective action has the effect of the centrifugal blower (X _1), it contributes greatly to the improved performance and cost reduction as the air conditioner (Z _1). In addition, the optimum aperture of the air intake port 6 can be made larger than the conventional one, and the pressure loss in the air filter 17 or the like can be suppressed small.

(2nd embodiment)

7 and 11 show a centrifugal blower X ₂ and an air conditioner Z ₂ according to a second embodiment of the present invention.

In this case, instead of the reinforcing ring 9 in the first embodiment, a ring body 20 having a predetermined width H in the centrifugal direction is attached to the impeller 1 in the centrifugal blower X ₂ . have. Since the other structure and effect are the same as that of 1st Embodiment, description is abbreviate | omitted.

By the way, the ring body 20 can be made into various shapes, as shown to FIGS. 8A-8L. In addition, what is shown below is an example to the last and of course, it can be set as shape other than illustration.

That is, as shown in FIG. 8A, the ring body 20 may be joined to the axial end surface of the blade 3, and as shown in FIG. 8B, the ring body 20 is inclined to the half hub side. 8C, the ring body 20 may be attached to the hub side in an inclined state, and as shown in FIG. 8D, the centrifugal end of the ring body 20 has an arcuate surface ( It may be 20a), and as shown in FIG. 8E, the centrifugal end part of the ring body 20 may be circular arc surface 20a, and the whole may be attached in the state which curved inclined to the half hub side. In this case, the formation of the circulation flow f ₂ is promoted by the coanda effect.

In addition, as shown in FIG. 8F, the surface on the half hub side of the ring body 20 may be the recessed portion 20b. In this case, since negative pressure is generated in the recess 20b, the formation of the circulation flow f ₂ is promoted. In addition, as shown in FIG. 8G, the surface of the half hub side of the ring body 20 may become the recessed part 20b, and may be attached in the inclined state to the hub side. Also in this case, formation of the circulation flow f ₂ is promoted similarly to the case shown in FIG. 8F. In addition, as shown in FIG. 8H, the surface on the hub side of the ring body 20 may be the recessed portion 20c. In this case, since negative pressure is generated in the recessed portion 20c, the formation of the circulation flow f ₂ is promoted.

In addition, as shown in FIG. 8I, the surface on the hub side of the ring body 20 may be attached to the recessed portion 20c and inclined on the hub side. Also in this case, formation of the circulation flow f ₂ is promoted similarly to the case shown in FIG. 8H. As shown in Fig. 8J, the ring body 20 may be formed of a member having a relatively thick thickness, and circular arc surfaces 20d and 20e may be formed on the side of the attachment portion and the end portion in the centrifugal direction, respectively. In this case, a smooth circulation flow f ₂ can be formed.

In addition, as shown in Fig. 8K, the ring body 20 is formed of a member having a relatively thick thickness, and circular arc faces 20d and 20e are formed on the side of the attachment portion and the centrifugal direction, respectively, and are inclined to the hub side. You may make it adhere in a state. In this case as well, as in the case shown in FIG. 8J, a smooth circulation flow f ₂ can be formed.

In addition, as shown in FIG. 8L, the inclined surface 2b inclined toward the half blade side is formed in the portion where the blade 3 is placed in the hub 2, while the ring body 20 has a relatively thick member. Of the inclined surface 3c (the hub 2 of which the circular body 20d, 20e is formed on the attachment part side and the centrifugal end side, respectively, and the ring body 20 is formed at the tip end of the blade 3). It may be attached to the inclined surface 2b). In this case, the removal direction of the metal mold | die at the time of shaping | molding can be made into the outer peripheral side.

Incidentally, the outer diameter of the blade 3 in the centrifugal blower X ₂ according to the present embodiment is D ₂ and the centrifugal width of the ring body 20 is H, and the suction side center Q of the air intake 6 is Q. When the microphone 12 was installed at a position of 1 m inclined at 45 degrees, the change in the minimum specific noise (Ks) with respect to the variable ki = H / D ₂ was obtained. The result of FIG. 9 was obtained.

According to the said result, it turns out that favorable driving sound characteristic is obtained in the range of 0.05 <ki <0.225. By the way, it is more preferable to set it as the range of 0.1 <ki <0.15. On the other hand, when ki = H / D≤0.05, the effect is small, and when ki = H / D≥0.225, adversely affects the formation of the circulation flow, and the circulation flow at the trailing edge of the blade 3 is weakened to improve aerodynamic performance. Inhibits.

Also, ring body 20 and the bell mouth 5, the distance to the L, and the bar examining the change in the minimum noise ratio (Ks) for a variable L / D _2, the results of FIG. 10 were obtained. According to the above results, in the range of L / D ₂ ≥0.169, it can be seen that the obtained a good operation noise characteristic.

FIG. 11 shows the ceiling-embedded air conditioner Z ₂ incorporating the centrifugal blower X ₂ according to the present embodiment. In this case, the heat exchanger 15 and the centrifugal blower X ₂ are arranged in the ventilation path 14 of the air flow W formed in the casing 13, and the motor fixing part 7 for fixing the motor 4 is provided. Is integrated with the top plate 13a of the casing 13. The air conditioner Z ₂ has a suction grill 16, an air filter 17, a drain pan 18, and an air blower outlet 19. In this way, because it can exert an effective action has the effect of the centrifugal blower (X _2), it contributes greatly to the improved performance and cost reduction as the air conditioner (Z _2). In addition, the optimum aperture of the air intake 6 can be made larger than the conventional one, and the pressure loss in the air filter 17 can be suppressed to be small.

In the case of the centrifugal blower which concerns on said each embodiment, it applies to the thing with few blades 3 (that is, 5-15 sheets).

(Third embodiment)

In Figures 12 to 16, the centrifugal blower (X ₃₎ and the air conditioner (Z ₃₎ according to a third embodiment of the present invention is shown.

As shown in Figs. 12 and 13, the centrifugal blower X ₃ has a disk-shaped hub 2 to which the rotating shaft 4a of the motor 4 is connected to the shaft center, and an outer peripheral portion of the hub 2; Is provided with an impeller 1 composed of a plurality of blades 3 erected at predetermined intervals along the circumferential direction, and a bell mouse 5 having an air inlet 6 at the air intake side of the impeller 1 is provided. It is arranged.

As shown in FIG. 13, the impeller 1 is inclined toward its front in the rotational direction, and the outer diameter side end portion 3b of each blade 3 is smaller than the inner diameter side end portion 3a. It is a retracting wing type (that is, a turbo fan type) located at the rear side of the rotation direction M of. In this case, since the ratio of the static pressure rise to the total pressure rise of the impeller 1 is large, the vortex scroll may be unnecessary. On the other hand, in the case of the centrifugal blower X ₃ according to the present embodiment, the number of blades 3 is much larger than the number of blades in the centrifugal blowers X ₁ and X ₂ according to the first and second embodiments. It is set (for example, 30-50 sheets).

Moreover, the recessed part 2a for accommodating the said motor 4 is formed in the shaft center part of the said hub 2. The motor fixing part 7 fixes the motor 4. The bearing boss 8 pivotally supports the rotation shaft 4a of the motor 4.

Moreover, the ring body 20 which has predetermined width | variety H in the centrifugal direction is provided in the impeller 1 of this embodiment similarly to 2nd Embodiment. In the case of this embodiment, the said ring body 20 is inclined toward the hub 2 side toward the centrifugal direction.

A distribution space S is formed on the back side (in other words, the outer circumferential side) of the bell mouse 5, and the air inlet 6 of the bell mouse 5 is formed from the ejection side of the impeller 1. the circulating flow (f ₂₎ is again sucked into the impeller 1 through the rear side is configured to be able to easily and surely formed. The shape of the air intake port 6 in the bell mouse 5 may be a straight shape, as in the first embodiment, or may be a wedge shape or a flare shape.

In the present embodiment, the inner diameter of the air inlet 6 at the bell mouse 5 is D ₀ , the inner diameter of the blade 3 at the impeller 1 is D ₁ , and the outer diameter of the blade 3 is represented. When D ₂

-0.3 <(D ₀ -D ₁ ) / (D ₂ -D ₁ ) <0.3. On the other hand, the number of blades 3 is 40.

In the centrifugal blower comprised as mentioned above, the following effect is acquired.

That is, the circulation flow f ₂ which passes through the back side of the air suction port 6 in the bell mouse 5 from the ejecting side of the impeller 1, and is sucked into the impeller 1 again is formed. Therefore, the air mainstream f ₁ passing through the blade 3 is attracted to the tip side of the blade 3 by the circulation flow f ₂ , and the wind speed distribution at the outlet portion of the blade 3 is improved to provide aerodynamic force. The performance can be improved and the noise of driving can be reduced. In addition, since the shroud is unnecessary, the integral molding of the impeller 1 can be performed, the cost can be reduced, and the mass productivity is excellent.

In addition, in this embodiment, the inner diameter of the air intake port 6 in the bell mouse 5 is D ₀ , and the inner diameter of the blade 3 in the impeller 1 is D ₁ of the blade 3. when the outer diameter to _{D 2, -0.3 <k = (} D 0 -D 1) / it is set such that _{(D 2 -D 1) <0.3} . In this way, as shown in FIG. 14, minimum non-noise Ks can be suppressed low, and further aerodynamic performance can be improved and operation noise can be reduced. On the other hand, when -O.3≥k = (D ₀ -D ₁ ) / (D ₂ -D ₁ ), the leading edge of the blade 3 does not work effectively, which hinders the improvement of aerodynamic performance. When k = (D ₀ -D ₁ ) / (D ₂ -D ₁ ) ≥ 0.3, the reverse flow f 'generated at the leading edge of the blade 3 is strengthened, and the blade 3 The circulation flow f ₂ at the trailing edge is weakened and the improvement of aerodynamic performance is inhibited.

Incidentally, the inner diameter of the blade ₃ in the centrifugal blower X ₃ according to the present embodiment is D ₁ , the outer diameter of the blade 3 is D ₂ , the inner diameter of the air inlet 6 is D ₀ , and air The microphone is installed at a position of 1 m 45 degrees inclined from the inlet side center of the inlet 6, and k = (D ₀ -D ₁ ) / (D ₂ -D ₁ ) as a variable for the lowest noise level (Ks). When the change was examined, the result shown in FIG. 14 was obtained. According to the above result, it turns out that favorable driving sound characteristic is obtained in the range of -0.3 <k <0.3.

The relationship between the outer diameter D ₂ of the blade ₃ in the centrifugal blower X ₃ and the centrifugal width H of the ring body 20 is the same as in the second embodiment. The relationship between the outer diameter D ₂ of the blade 3 and the distance L between the ring body 20 and the bell mouse 5 in the centrifugal blower X _{3 is as} shown in FIG. 15, and L / D _In the range of _2? 0.07, the lowest non-noise (Ks) can be suppressed low. At L / D ₂ <0.07, the lowest specific noise (Ks) increases rapidly.

By the way, when the exit height B of each blade 3 in the impeller 1 becomes small, the shaking of the streamline f ₁ of the air flow at the exit side of the impeller 1 becomes large, and eventually the circulation flow f _2. ) Closes the flow path between the blades 3. As a result, the aerodynamic performance drops sharply as shown by the solid line in FIG. 16, and a problem arises in that the hysteresis characteristic shown by the dotted line in FIG. In this case, the number of blades does not matter.

Thus, in this embodiment, it is set to B / D ₂ ≥0.113. In this way, the problem that the streamline f ₁ of the air flow at the outlet side of the impeller 1 is shaken is solved, and as shown by the dashed-dotted line in FIG. 16, stable performance is obtained. On the other hand, when B / D ₂ <0.113, the streamline of the air flow at the outlet side of the impeller 1 will be greatly shaken, and eventually the circulation flow f ₂ will block the flow path between the blades 3 and the performance will suddenly decrease. do.

Incidentally, when the change in the maximum flow rate coefficient Φmax (the case where there is no deterioration is set as the reference value = 1) with respect to B / D ₂ in the centrifugal blower X ₃ according to the present embodiment is examined, it is shown in Fig. 17. The result was obtained. Here,? Max = Qmax / 60 (? D ₂ B) u ₂ , u ₂ =? D ₂ N, Qmax: total amount of open air (m 3 / min), N: number of revolutions (rpm). From the results in FIG. 17, it can be seen that in B / D _2? O.113, the maximum flow rate coefficient? Max represents the reference value = 1.

Figure 18 is, the centrifugal blower (X ₃₎ a ceiling embedded type air conditioner (Z ₃₎ built according to the present embodiment is shown. In this case, the heat exchanger 15 and the centrifugal blower X ₃ are arranged in the ventilation path 14 of the air flow W formed in the casing 13, and the motor fixing part 7 which fixes the motor 4 is provided. ) Is integrated with the top plate 13a of the casing 13. The air conditioner Z ₃ has a suction grill 16, an air filter 17, a drain pan 18 and an air blower outlet 19. In this way, since the centrifugal blower (X ₃₎ to exert effective functions and effects which, contributes greatly to the improved performance and cost reduction as the air conditioner (Z _3). In addition, the optimum aperture of the air intake port 6 can be made larger than the conventional one, and the pressure loss in the air filter 17 can be suppressed to be small.

Next, a modification of the centrifugal blower X ₃ according to the third embodiment will be described.

(Modification Example I)

As shown in FIG. 19, you may make it incline the tip side edge part of each blade 3 in the impeller 1 to the inclination-angle substantially equal to the inclination-angle of the ring body 20. As shown in FIG. Also in this case, the relationship between D ₀ , D ₁ , D ₂ , H, L, and B is the same as described above.

(Modification Example II)

As shown in FIG. 20, the tip side end of each blade 3 in the impeller 1 is inclined at an inclination angle approximately equal to that of the ring body 20, and the inlet end of each blade 3 is You may make it incline so that it may approach to the centrifugal direction of the impeller 1 as it goes to the hub side. Also in this case, the relationship between D ₀ , D ₁ , D ₂ , H, L, and B is the same as described above.

(Modification Example III)

As shown in FIG. 21, the tip side end of each blade 3 in the impeller 1 is inclined at an inclination angle approximately equal to the inclination angle of the ring body 20, and the inlet end of each blade 3 is hubed. It may be inclined so as to approach the centrifugal direction of the impeller 1 as it goes to the side, and the serration 21 may be formed in the said inlet side edge part. In this case, since the formation of the boundary layer on the blade surface is suppressed, the blowing sound is reduced. Also in this case, the relationship between D ₀ , D ₁ , D ₂ , H, L, and B is the same as described above.

(4th embodiment)

Figure 22 is provided with a centrifugal blower (X ₄₎ according to a fourth embodiment of the present invention. In this case, the outer diameter D ₃ of the hub 2 constituting the impeller 1 is set smaller than the outer diameter D ₂ of each blade 3. In this case, the opening 22 is formed in the outer peripheral portion on the hub side in each blade 3, and as described later, when the inclined flow diffuser 23 is provided (see FIG. 29), the blade 3 The blowout resistance of the blown air stream becomes small. Since the other structure and effect are the same as that of 3rd Embodiment, description is abbreviate | omitted.

Also in this embodiment, when the exit side height B of each blade 3 in the impeller 1 becomes small similarly to 3rd embodiment, the streamline f of the airflow in the exit side of the impeller 1 will be reduced. ₁ ) the shaking becomes large, and eventually the circulation flow f ₂ closes the flow path between the blades 3, and as shown by the solid line of FIG. 16, the aerodynamic performance suddenly decreases, and the dotted line of FIG. The problem arises that hysteresis characteristics occur. In this case, the number of blades does not matter.

Thus, in this embodiment, it is set to B / D ₂ ≥0.08. The reason why the upper limit of the B / D ₂ is set smaller than in the case of the third embodiment is that the opening 22 is formed in the outer peripheral portion of the hub side in each blade 3. In this way, the problem that the streamline f ₁ of the air flow at the outlet side of the impeller 1 is shaken is solved, and stable performance is obtained as shown by the dashed-dotted line in FIG. On the other hand, when B / D ₂ <0.08, the streamline of the air flow at the outlet side of the impeller 1 is greatly shaken, and eventually the circulation flow f ₂ closes the flow path between the blades 3, 3... Performance drops sharply.

Incidentally, when the change in the maximum flow rate coefficient Φ max (the case where there is no degradation is set as the reference value = 1) with respect to B / D ₂ in the centrifugal blower X ₄ according to the present embodiment is examined, the result of FIG. Obtained. Here,? Max = Qmax / 60 (? D ₂ B) u ₂ , u ₂ =? D ₂ N, Qmax: total amount of open air (m 3 / min), N: number of revolutions (rpm). According to from the results in Fig. 23, B / D ₂ ≥0.08, a maximum flow rate coefficient Φmax be seen that represents the reference value = 1.

Next, the modification of the centrifugal blower X4 which concerns on _4th Embodiment is demonstrated.

(Modification Example I)

As shown in FIG. 24, you may make it incline the tip side edge part of each blade 3 in the impeller 1 to the inclination-angle substantially equal to the inclination-angle of the ring body 20. As shown in FIG. Also in this case, the relationship between D ₀ , D ₁ , D ₂ , H, L, and B is the same as described above.

(Modification Example II)

As shown in FIG. 25, the tip side end of each blade 3 in the impeller 1 is inclined at an inclination angle approximately equal to the inclination angle of the ring body 20, and the inlet end of each blade 3 is hub side. You may make it incline so that it may approach to the centripetal direction of the impeller 1 as it faces to the direction of the. Also in this case, the relationship between D ₀ , D ₁ , D ₂ , H, L, and B is the same as described above.

(Modification Example III)

As shown in FIG. 26, the tip side end of each blade 3 in the impeller 1 is inclined at an inclination angle approximately equal to the inclination angle of the ring body 20, and the inlet end of each blade 3 is hubed. It may be inclined so as to approach the centripetal direction of the impeller 1 as it goes to the side, and the serration 21 may be formed in the said inlet side edge part. In this case, since the formation of the boundary layer on the blade surface is suppressed, the blowing sound is reduced. Also in this case, the relationship between D ₀ , D ₁ , D ₂ , H, L, and B is the same as described above.

(Modification Example IV)

As shown in FIG. 27, the impeller 1 may be made into the inclination-flow fan type in which the outer peripheral side in the hub 2 (namely, the part in which the blade 3 is provided) is inclined. Also in this case, the relationship between D ₀ , D ₁ , D ₂ , H, L, and B is the same as described above.

(Modification example V)

As shown in FIG. 28, the impeller 1 is made into the oblique-flow fan type in which the outer peripheral side (that is, the part in which the blade 3 is installed) in the hub 2 is inclined, and also each of the blades 3 You may make it incline so that the inlet side edge part may approach the centrifugal direction of the impeller 1 as it goes to the hub side. Also in this case, the relationship between D ₀ , D ₁ , D ₂ , H, L, and B is the same as described above.

On the other hand, it is that centrifugal blower (X ₄₎ of the embodiment also be incorporated in the air conditioner as well.

(5th embodiment)

29 is provided with a centrifugal blower (X ₅₎ according to a fifth embodiment of the present invention. In this case, the outer diameter D ₃ of the hub 2 constituting the impeller 1 is set smaller than the outer diameter D ₂ of each blade 3, and at the ejecting side of the impeller 1, the impeller ( The inclined flow centrifugal diffuser 23 which inclines the blown out air flow from 1) and guides it further in the centrifugal direction from the rear side is provided. In this way, the opening 22 is formed in the outer peripheral part of the hub side in each blade 3, and the blowout resistance of the airflow blown out from the blade 3 becomes small, and the airflow blown out from the impeller 1 is carried out. The static pressure recovery of the dynamic pressure at is effectively performed, which greatly contributes to the performance improvement (that is, high efficiency and low noise). Since the other structure and effect are the same as that of 3rd Embodiment, description is abbreviate | omitted.

Next, the modification of the centrifugal blower X5 which concerns on _5th Embodiment is demonstrated.

(Modification Example I)

As shown in FIG. 30, you may make it incline the tip side edge part of each blade 3 in the impeller 1 to the inclination angle which is substantially the same as the inclination angle of the ring body 20. As shown in FIG. Also in this case, the relationship between D ₀ , D ₁ , D ₂ , H, L, and B is the same as described above.

(Modification Example II)

As shown in FIG. 31, the tip side end of each blade 3 in the impeller 1 is inclined at an inclination angle approximately equal to the inclination angle of the ring body 20, and the inlet end of each blade 3 is hubed. You may make it incline so that it may approach to the centripetal direction of the impeller 1 as it goes to the side. Also in this case, the relationship between D ₀ , D ₁ , D ₂ , H, L, and B is the same as described above.

In the case of the centrifugal blowers according to the third to fifth embodiments, the number of blades 3, 3... Is applied to a large number (ie, 30 to 50 sheets).

On the other hand, it is to assemble a centrifugal blower (X ₄₎ also, the air conditioner according to the present embodiment as well. Moreover, of course, the same effect is acquired also in the case of a vortex casing.

(Modification Example III)

The centrifugal blower X ₅ of FIG. 32 uses the same oblique flow centrifugal diffuser 23 as in FIGS. 29 to 31 with respect to the structure of the impeller and bell mouse of the centrifugal blower X ₃ according to the third embodiment described above. It is characterized by the installation.

In this way, as shown in the drawing, the wind speed distribution at the outlet of each blade 3 of the impeller 1 is increased at the suction port side by the guide action of the ring body 20 described above, while relatively at the hub 2 side. Becomes smaller. However, after passing through the diffuser passage in the inclined flow direction, which is biased on the hub 2 side, the blown air on the hub 2 side is increased in the inclined flow direction and finally taken out from the outlet in the centrifugal direction. As a result, the blowout rate of the blowout flow out from the outlet in the centrifugal direction becomes uniform throughout. Therefore, the blowing efficiency is improved, and the silent performance is effectively improved.

In order to confirm this action, for example, the centrifugal blower X ₃ (FIG. 33) according to the modification I of the third embodiment shown in FIG. 19 described above, and the inclined flow centrifugal diffuser 23 in the conventional shroud centrifugal blower 23. In contrast to the wind speed distribution of each installed (Fig. 34) is as follows.

That is, in the conventional centrifugal blower with the shroud shown in Fig. 34, the air flow sucked from the air intake port 6 of the bell mouse 5 flows toward the hub 2 side, so that at the outlet of each blade 3, The wind velocity distribution of is small at the air intake port 6, becomes larger on the hub 2 side, and is largely biased on the hub 2 side.

Moreover, since the flow biased on the side of the hub 2 passes through the passage in the oblique flow direction of the oblique flow centrifugal diffuser 23, it is further deflected to the rear and taken out in the centrifugal direction as it is. The wind speed distribution of the air stream is largely biased backwards.

In contrast, in the case of the centrifugal blower X ₃ according to the modification I of the third embodiment shown in FIG. 33, as described above, the ring body 20 is shrouded and, moreover, the outer periphery of the axial end of the blade 3. ) Is provided, and the mainstream f ₁ is attracted to the distal end side of the blade 3 by the circulation flow f ₂ formed by the ring body 20, so that the exit portion of the blade 3 by that amount. The wind speed distribution at is significantly improved. However, on the contrary, the blowout air of the ring body 20 portion is large and does not necessarily become uniform when viewed as the entire blowout port.

On the other hand, in the case of this embodiment, the modification gradient flow distal of III that the transition type radial direction to the passage shape changed in a radial direction of the centrifugal fan having a diffuser (23) (X ₅₎ is, as shown in FIG. 32 Finally, since the wind speed distribution of the air flow blown out from the outlet in the centrifugal direction becomes uniform throughout, the noise reduction effect is as shown in FIG. 35, in the case of the conventional shrouded centrifugal blower shown in FIG. In comparison to that much larger.

(6th Embodiment)

36 and 37 show the impeller of the centrifugal blower according to the sixth embodiment of the present invention.

The impeller 1 of this centrifugal blower is, for example, a disk-shaped hub 2 to which the rotary shaft 4a of the motor 4 is connected to the shaft portion, and the hub 2 as shown in FIGS. 36 and 37. It consists of the some blade | wing 3 which penetrated at the predetermined | prescribed interval along the circumferential direction at the outer periphery part of (circle).

In each blade 3 of this impeller 1, the inner diameter side end portion 3a, which is the leading edge thereof, is inclined toward the front in the rotational direction, and the outer diameter side end portion 3b, which is the rear edge, has the impeller 1 more than the inner diameter side end portion 3a. It is located in the rear side of the rotation direction M of the camber wire, and it is set as the retraction wing type (so-called turbo fan type) which the camber wire protruded in the rotation direction.

The number of the blades 3 of the impeller 1 is set to, for example, 20 to 50 sheets, and a ring body 20 having a predetermined width H in the centrifugal direction is placed on the outer circumference of the bell mouse side end portion. It is. In the case of this embodiment, the bell-mouse side edge part of the said ring body 20 and the blade 3 is a shape which inclines toward the hub 2 side as it goes to a centrifugal direction, respectively like FIG. The other structure is basically the same as that of each embodiment mentioned above.

Also in the centrifugal blower of this embodiment which comprised such an impeller 1 in combination with the bellows 5 same as that of each said embodiment, without providing a shroud, the following beneficial effects are the same as that of each said embodiment. Obtained.

That is, due to the presence of the ring body 20, the circulation flow f ₂ which is sucked into the impeller 1 again through the back side of the air inlet 6 at the bell mouth 5 from the ejection side of the impeller 1 Is formed, the air main stream f ₁ passing through the blade 3 is effectively attracted to the tip side of the blade 3 by the circulation flow f ₂ , and at the outlet portion of the blade 3 The wind speed distribution is improved evenly and the aerodynamic performance can be improved and the driving noise can be reduced.

In addition, since the shroud is unnecessary, integral molding of the impeller 1 can be performed, the structure can be simplified, the cost can be reduced, and the mass productivity is excellent.

(Seventh embodiment)

38 and 39 show an impeller of a centrifugal blower according to the seventh embodiment of the present invention. As shown in FIGS. 38 and 39, the impeller 1 of the centrifugal blower includes a disc-shaped hub 2 to which a rotation shaft 4a of the motor 4 is connected to the shaft center, and the hub 2. And a plurality of blades 3 placed in the outer circumferential portion at a predetermined interval in the circumferential direction.

In each blade 3 of this impeller 1, the inner diameter side end portion 3a, which is the leading edge thereof, is inclined toward the front in the rotational direction, and the outer diameter side end portion 3b, which is the rear edge, has the impeller 1 more than the inner diameter side end portion 3a. It is located in the rear side of the rotation direction M of the camber wire, and becomes a retracting wing type (so-called turbo fan type) in which the camber wire was concave in the rotation direction.

The number of the blades 3 of the impeller 1 is set to, for example, 20 to 50 sheets, and a ring body 20 having a predetermined width H in the centrifugal direction is placed on the outer circumference of the bell mouse side end portion. It is. In the case of this embodiment, the bell-mouse side edge part of the said ring body 20 and the blade 3 is inclined to the hub 2 side, as shown in FIG. 24, respectively, toward a centrifugal direction. The other structure is basically the same as that of each embodiment mentioned above.

Also in the centrifugal blower of this embodiment which comprised such an impeller 1 in combination with the bellows 5 similar to the thing of said each embodiment, without providing a shroud, the following advantageous effects as the same as that of each said embodiment are as follows. Is obtained.

That is, due to the presence of the ring body 20, the circulation flow f ₂ which is sucked into the impeller 1 again through the back side of the air inlet 6 at the bell mouth 5 from the ejection side of the impeller 1 ) Is formed, the air mainstream f ₁ passing through the blade 3 is effectively attracted to the tip side of the blade 3 by the circulation flow f ₂ , and the wind speed at the outlet portion of the blade 3 The distribution is improved evenly and the aerodynamic performance can be improved and the driving noise can be reduced.

In addition, since the shroud is unnecessary, integral molding of the impeller 1 can be performed, the structure can be simplified, the cost can be reduced, and the mass productivity is excellent.

(8th Embodiment)

40 and 41 show an impeller of a centrifugal blower according to an eighth embodiment of the present invention. As shown in FIGS. 40 and 41, the impeller 1 of the centrifugal blower is, for example, a disk-shaped hub 2 to which the rotary shaft 4a of the motor 4 is connected to the shaft center, and the hub 2. It consists of the some blade | wing 3 which penetrated at the predetermined | prescribed interval along the circumferential direction at the outer periphery part of (circle).

In each blade 3 of this impeller 1, the inner diameter side end portion 3a, which is its leading edge, is inclined toward the front in the rotational direction, and the outer diameter side end portion 3b, which is the trailing edge, is impeller 1 than the inner diameter side end portion 3a. It is located in the rear side of the rotation direction M of the camber wire, and has a linear retraction wing type (so-called turbo fan type).

The number of blades 3 of the impeller 1 is set to, for example, a plurality of 20 to 50 pieces, and a ring body having a predetermined width H in the centrifugal direction on the outer circumference of the bell mouse side end portion ( 20) is laid. In the case of this embodiment, the bell-mouse side edge part of the said ring body 20 and the blade 3 is in the shape which inclines toward the hub 2 side, respectively, as it faces a centrifugal direction, as in FIG. The other structure is basically the same as that of each embodiment mentioned above.

Also in the centrifugal blower of this embodiment which comprised such an impeller 1 in combination with the bellows 5 similar to the thing of said each embodiment, without providing a shroud, the following advantageous effects as the same as that of each said embodiment are as follows. Is obtained.

That is, due to the presence of the ring body 20, the circulation flow f ₂ which is sucked into the impeller 1 again through the back side of the air inlet 6 at the bell mouth 5 from the ejection side of the impeller 1 Is formed, the air main stream f ₁ passing through the blade 3 is effectively attracted to the tip side of the blade 3 by the circulation flow f ₂ , and at the outlet portion of the blade 3 The wind speed distribution is improved evenly and the aerodynamic performance can be improved and the driving noise can be reduced. In addition, since the shroud is unnecessary, integral molding of the impeller 1 can be performed, the structure can be simplified, the cost can be reduced, and the mass productivity is excellent.

Now, the outer diameter side end part 3b of each blade 3 as mentioned above is located in the rear side of the rotation direction M of the impeller 1 rather than the inner diameter side end part 3a, and a camber wire employ | adopts a linear retraction wing | blade. In the graph of FIG. 43, the centrifugal blower constructed by employing one impeller was measured using the number of blades as a parameter, and the result of measuring the highest static pressure efficiency ratio (reference value 1.0) and the lowest non-noise level ratio (reference value level ± 0) is shown in the graph of FIG. do.

The centrifugal blower provided for the measurement has the impeller configuration shown in Figs. 40 and 41, and the inlet angle θ ₁ and the outlet angle θ ₂ of each blade 3 are as shown in Fig. 42, θ ₁ = 25 °, θ ₂ = 50 °, and the inlet height B ₁ , the outlet height B ₂ of the blade 3, and the inner diameter D ₀ of the air inlet 6 of the bell mouse 25. The inner diameter D ₁ and outer diameter D ₂ of the blade 3 are respectively B ₁ = 35 mm, B ₂ = 30 mm, D ₀ = 130 mm, and D ₁ = 110 as shown in FIG. 44. Mm, D ₂ = 160 mm.

If it is determined from the measurement result in FIG. 43, when the number of the blades 3 is less than 20 sheets, the above-described circulation flow (f ₂₎ as shown by f ₂ 'in FIG. 44 larger on the inner side of the blade 3 Performance degrades. On the other hand, if the number of blades exceeds 50, the performance P is deteriorated because the interval P between the leading edges of the blades 3 becomes too narrow.

On the other hand, in the case where the number of the blades 3 is 50 to 20, the problems as described above are unlikely to occur, the static pressure efficiency ratio is high, and the non-noise level ratio can be suppressed as low as possible. That is, it turns out that a quiet performance can be improved efficiently, raising an air blow efficiency.

The performance improvement by the same number of blades as this can be expected almost similarly also in the case of the structure of each of 12th embodiment demonstrated above FIG. 6, FIG. 7, and later.

(Ninth embodiment)

45 and 46 show a centrifugal blower according to a ninth embodiment of the present invention. As shown in FIGS. 45 and 46, the impeller 1 of the centrifugal blower includes a disc-shaped hub 2 to which the rotation shaft 4a of the motor 4 is connected to the shaft center, and the hub 2. It consists of the some blade | wing 3 which penetrated at the predetermined | prescribed interval along the circumferential direction at the outer periphery part of (circle).

In each blade 3 of the impeller 1, the inner diameter side end portion 3a, which is the leading edge thereof, does not incline toward any of the front and rear directions of the rotation direction M, and the camber wire extends linearly in the radial direction. It becomes the radial wing type (so-called radial plate fan type).

The number of blades 3 of the impeller 1 is set to, for example, a plurality of 30 to 72 sheets, and a ring body having a predetermined width H in the centrifugal direction on the outer circumference of the bell mouse side end. 20) is laid. In the case of this embodiment, the bell-mouse side edge part of the said ring body 20 and the blade 3 is in the shape which inclines toward the hub 2 side, respectively, toward the centrifugal direction like FIG. 44 mentioned above. The other structure is basically the same as that of each embodiment mentioned above.

Also in the centrifugal blower of this embodiment which comprised such an impeller 1 in combination with the bellows 5 similar to the thing of said each embodiment, without providing a shroud, the following advantageous effects as the same as that of each said embodiment are as follows. Is obtained.

That is, due to the presence of the ring body 20, the circulation flow f ₂ which is sucked into the impeller 1 again through the back side of the air inlet 6 at the bell mouth 5 from the ejection side of the impeller 1 ) Is formed, the air main stream f ₁ passing through the blade 3 is efficiently attracted to the tip side of the blade 3 by the circulation flow f ₂ , and at the outlet portion of the blade 3 The wind speed distribution is improved evenly and the aerodynamic performance can be improved and the driving noise can be reduced.

Moreover, since the shroud is unnecessary, integral molding of the impeller 1 becomes possible, and the cost can be drastically reduced by simplifying the structure and improving the mass production.

(10th embodiment)

47 and 48 show an impeller of a centrifugal blower according to a tenth embodiment of the present invention. The impeller 1 of this centrifugal blower is, for example, a disk-shaped hub 2 to which the rotary shaft 4a of the motor 4 is connected to the shaft center, and the hub 2 as shown in FIGS. 47 and 48. It consists of the some blade | wing 3 which penetrated at the predetermined | prescribed interval along the circumferential direction at the outer periphery part of (circle).

In each blade 3 of this impeller 1, the inner diameter side end portion 3a, which is the leading edge thereof, does not incline in any of the front and rear directions of the rotation direction M, and the camber wire is the rotation direction M. It is a radial wing type (the first variant type of the radial plate fan) which is slightly inclined to the rear of the.

The number of blades 3 of the impeller 1 is set to, for example, a plurality of 30 to 72 sheets, and a ring body having a predetermined width H in the centrifugal direction on the outer circumference of the bell mouse side end. 20) is laid. In the case of this embodiment, the bell-mouse side edge part of the said ring body 20 and the blade 3 is in the shape which inclines toward the hub 2 side as it goes to the centrifugal direction, respectively, similarly to the case of FIG. The other structure is basically the same as that of each embodiment mentioned above.

Also in the centrifugal blower of this embodiment which comprised such an impeller 1 in combination with the bellows 5 similar to the thing of said each embodiment, without providing a shroud, the following advantageous effects as the same as that of each said embodiment are as follows. Is obtained.

That is, due to the presence of the ring body 20, the circulation flow f ₂ which is sucked into the impeller 1 again through the back side of the air inlet 6 at the bell mouth 5 from the ejection side of the impeller 1 ) Is formed, the air mainstream f ₁ passing through the blade 3 is effectively attracted to the tip side of the blade 3 by the circulation flow f ₂ , and the wind speed at the outlet portion of the blade 3 The distribution is improved evenly, and the aerodynamic performance can be improved and the driving noise can be reduced. In addition, since the shroud is unnecessary, integral molding of the impeller 1 becomes possible, and the structure can be greatly reduced due to the simplification of the structure and the improvement of mass productivity, and the excellent mass productivity.

Now, with respect to the centrifugal blower of the present embodiment, the results of measuring the maximum static pressure efficiency ratio (reference value 1.0) and the lowest non-noise level ratio (reference value level ± O) using the number of blades as parameters are shown in the graph of FIG. 50. .

The centrifugal blower provided for the measurement has the impeller configuration shown in FIG. 47 and FIG. 48, and the inlet angle θ ₁ and the outlet angle θ ₂ of each blade 3 are as shown in FIG. 49. , θ ₁ = 90 °, θ ₂ = 75 °, and the inlet height B ₁ , the outlet height B _{2 of the} blades 3, 3..., and the air inlet 6 of the bell mouse 5. The inner diameter D ₀ , the inner diameter D ₁ and the outer diameter D ₂ of the blade 3 of the impeller 1 are B ₁ = 25 mm, B ₂ = 20 mm, D ₀ = 130 mm, D ₁ = 90 Mm, D ₂ = 150 mm.

Judging from the measurement results in FIG. 50, in the case of the present configuration, when the number of blades 3 is less than 30, the above-described circulation flow f ₂ is indicated by f ₂ ′ in FIG. 44. The suction performance deteriorates because it enters large inside. On the other hand, when the number of blades exceeds 72 sheets, the space P between the leading edges 3a and 3a of the blade 3 becomes too narrow, resulting in deterioration in performance.

On the other hand, in the case where the number of the blades 3 is 72 to 30, the above-described problems are less likely to occur, the static pressure efficiency ratio is high, and the non-noise level ratio can be sufficiently reduced. That is, it turns out that a quiet performance can be improved efficiently, raising an air blow efficiency.

The performance improvement by the same number of blades can be expected almost similarly in the case of the structure of each said 9th and 11th embodiment demonstrated next.

(Eleventh embodiment)

51 and 52 show the impeller of the centrifugal blower according to the eleventh embodiment of the present invention. The impeller 1 of this centrifugal blower is, for example, a disk-shaped hub 2 to which the rotating shaft 4a of the motor 4 is connected to the shaft center portion, and the hub 2 as shown in FIGS. 51 and 52. It consists of the some blade | wing 3 which penetrated at the predetermined | prescribed interval along the circumferential direction at the outer periphery part of (circle).

In each blade 3 of the impeller 1, the inner diameter side end portion 3a, which is the leading edge thereof, does not incline in any of the front and rear directions of the rotation direction M, and the camber wire is the rotation direction M. It is of the radial wing type (second modification type of the said radial plate fan) inclined slightly forward of the.

The number of the blades 3 of the impeller 1 is set to, for example, a plurality of 30 to 72 sheets in the same manner as above, and a predetermined width H in the centrifugal direction on the outer circumference of the bell mouse side end portion. The ring body 20 which has a is provided. In the case of this embodiment, the bell-mouse side edge part of the said ring body 20 and the blade 3 is in the shape which inclines toward the hub 2 side as it goes to a centrifugal direction, respectively like FIG. The other structure is basically the same as that of each embodiment mentioned above.

Also in the centrifugal blower which comprised such an impeller 1 in combination with the bellows 5 similar to the thing of said each embodiment, without providing a shroud, the following advantageous effects and effects similar to those of each said embodiment are acquired.

That is, due to the presence of the ring body 20, the circulation flow f ₂ which is sucked into the impeller 1 again through the back side of the air inlet 6 at the bell mouth 5 from the ejection side of the impeller 1 ) Is formed, the air mainstream f ₁ passing through the blade 3 is effectively attracted to the tip side of the blade 3 by the circulation flow f ₂ , and the wind speed at the outlet portion of the blade 3 The distribution is improved evenly, and the aerodynamic performance can be improved and the driving noise can be reduced.

In addition, since the shroud is unnecessary, integral molding of the impeller 1 becomes possible, and the structure can be greatly reduced and the mass productivity can be greatly reduced.

(12th Embodiment)

53 and 54 show an impeller of a centrifugal blower according to a twelfth embodiment of the present invention.

The impeller 1 of this centrifugal blower is, for example, a disk-shaped hub 2 to which the rotating shaft 4a of the motor 4 is connected to the shaft center portion, and the hub 2 as shown in FIGS. 53 and 54. It consists of the some blade | wing 3 which penetrated at the predetermined | prescribed interval along the circumferential direction at the outer periphery part of (circle).

Each blade 3 of the impeller 1 is of a radial blade type (radial tip fan type having an exit angle θ ₁ of about 90 °) in which the camber wire protrudes in the rotational direction. .

The number of the blades 3 of the impeller 1 is set to, for example, 20 to 50 sheets, in the same manner as in the sixth and seventh embodiments, and in the centrifugal direction on the outer circumference of the bell mouse side end. A ring body 20 having a predetermined width H is provided. In the present embodiment, the bell mouse side ends of the ring body 20 and the blade 3 are inclined toward the hub 2 side in the same direction as in FIG. 44 described above, respectively, toward the centrifugal direction. have. The other structure is basically the same as that of each embodiment mentioned above.

Also in the centrifugal blower of this embodiment which comprised such an impeller 1 in combination with the bellows 5 similar to the thing of said each embodiment, without providing a shroud, the following advantageous effects as the same as that of each said embodiment are as follows. Is obtained.

That is, due to the presence of the ring body 20, the circulation flow f ₂ which is sucked into the impeller 1 again through the back side of the air inlet 6 at the bell mouth 5 from the ejection side of the impeller 1 Is formed, the air main stream f ₁ passing through the blade 3 is effectively attracted to the tip side of the blade 3 by the circulation flow f ₂ , and at the outlet portion of the blade 3 The wind speed distribution is improved evenly, and the aerodynamic performance can be improved and the driving noise can be reduced.

Moreover, since the shroud is unnecessary, integral molding of the impeller 1 becomes possible, and the cost can be drastically reduced by simplifying the structure and improving the mass productivity.

(13th Embodiment)

Next, the structure of the main part of the centrifugal blower which concerns on 13th Embodiment of this invention is shown in FIGS.

The impeller 1 of this centrifugal blower is, for example, as shown in Figs. 55 to 58, a disk-shaped hub 2 in which a rotating shaft of a motor is connected to the shaft center in the same manner as in the above embodiments, and The outer periphery of the hub 2 is composed of a plurality of blades 3 which are placed at a predetermined interval along the circumferential direction.

Each blade 3 of this impeller 1 has a front inclined vane type 3A (Fig. 57) in which the whole is inclined at a predetermined angle in front of the rotation direction M, or vice versa rear inclined vane type. 3B (FIG. 58).

In any of these types, the number of the blades 3 of the impeller 1 is set to, for example, a plurality of 30 to 72 sheets, and is set in the centrifugal direction on the outer circumference of the bell mouse side end. A ring body 20 having a width H of is laid. In the case of this embodiment, as shown from FIG. 55, the bell-mouse side edge part of the said ring body 20 and the blade 3 is inclined toward the hub 2 side as it goes to a centrifugal direction, respectively. The other structure is the same as that of each embodiment mentioned above.

Also in the centrifugal blower of this embodiment which comprised such an impeller 1 in combination with the bellows 5 similar to the said each embodiment, without providing a shroud, the following effects and effects similar to the said each embodiment are the same. Obtained.

That is, by the ring body 20, the circulation flow f ₂ which passes through the back side of the air intake port 6 in the bell mouse 5 from the ejecting side of the impeller 1 and is sucked into the impeller 1 again is formed. Therefore, the air main stream f ₁ passing through the blade 3 is attracted to the tip side of the blade 3 by the circulation flow f ₂ , and the wind speed distribution at the outlet portion of the blade 3 is improved. As a result, aerodynamic performance can be improved and driving noise can be reduced. In addition, since the shroud is unnecessary, integral molding of the impeller 1 can be performed, the structure can be simplified, the cost can be reduced, and the mass productivity is excellent.

In the case of such a configuration, also in relation to the inner diameter D ₀ of the air intake port 6 of the bell mouse 5, the following specific effects are produced.

(A) When the blade 3 is the front slanted blade 3A

In this case, for example, as shown in Fig. 57, the blades 3 and 3A act in the direction of sucking the circulation flow f ₂ formed by the ring body 20, so that a strong circulation flow f ₂ is formed. .

In addition, as shown by the symbol 6A in FIG. 55, even when the inner diameter D ₀ of the air inlet 6 of the bell mouse 5 is enlarged, the strong circulation flow f ₂ causes the blade 3, ( It does not deeply go to the inside of 3A), and it circulates smoothly in the vicinity of the ring body 20. As a result, good blowing performance can be realized.

(B) the blade 3 is a rear bevel blade 3B

In this case, for example, as shown in FIG. 58, the blades 3 and 3B act in a direction where it is difficult to suck the circulation flow f ₂ formed by the ring body 20. Furthermore, as in 55 as shown by reference numeral 6B, even when reducing the inner diameter (D ₀₎ of the air intake port 6 of the bell mouth (5), the circulation flow (f _2), the blade (3), (3B It does not go deeply to the inner side of), and it circulates smoothly in the ring body 20 vicinity. As a result, good blowing performance can also be realized.

(14th Embodiment)

59 and 60 show the configuration of the main parts of the centrifugal blower according to the fourteenth embodiment of the present invention.

The impeller 1 of this centrifugal blower is, for example, a disk-shaped hub 2 in which a rotating shaft of a motor is connected to the shaft center in the same manner as in each of the above embodiments, as shown in FIGS. 59 and 60, and the hub. The outer peripheral portion of (2) is composed of a plurality of blades 3 which are placed at a predetermined interval along the circumferential direction.

Each blade 3 of this impeller 1 has a front inclined vane type 3A of which the tip 3C is inclined at a predetermined angle in front of the rotation direction M, or a reverse inclined vane type. 3B (bending line L).

And also in any of those types, the number of the blades 3 of the impeller 1 is set to, for example, a plurality of 30 to 72 sheets, and predetermined in the centrifugal direction on the outer periphery of the bell mouse side end. A ring body 20 having a width H of is laid. In the present embodiment, the bell mouse side ends of the ring body 20 and the blade 3 are inclined toward the hub 2 side as shown in Fig. 59, respectively, toward the centrifugal direction. The other structure is basically the same as that of each embodiment mentioned above.

Also in the centrifugal blower which comprised such an impeller 1 in combination with the same bell mouse 5 as the thing of said each embodiment as shown in FIG. 59, the following effects and effects similar to those of each said embodiment are acquired.

That is, by the ring body 20, the circulation flow f ₂ which passes through the back side of the air intake port 6 in the bell mouse 5 from the ejecting side of the impeller 1 and is sucked into the impeller 1 again is formed. Therefore, the air mainstream f ₁ passing through the blade 3 is attracted to the tip side of the blade 3 by the circulation flow f ₂ , and the wind speed distribution at the outlet portion of the blade 3 is improved. As a result, aerodynamic performance can be improved and driving noise can be reduced. In addition, since the shroud is unnecessary, integral molding of the impeller 1 can be performed, the structure can be simplified, the cost can be reduced, and the mass productivity is excellent.

In such a configuration, also in relation to the inner diameter D ₀ of the air inlet 6 of the bell mouse 5, the following distinctive working effects are produced.

(A) When tip 3C of blade 3 is front slanted blade 3A inclined forward in the rotational direction

In this case, for example, as shown in FIG. 60, the blades 3 and 3A act in a direction of sucking the circulation flow f ₂ formed by the ring body 20, and a relatively strong circulation flow f ₂ is applied. Is formed.

In addition, as shown by the symbol 6A in FIG. 59, even when the inner diameter D ₀ of the air intake port 6 of the bell mouse 5 is increased, the relatively strong circulation flow f ₂ is applied to the blade 3, It circulates smoothly in the vicinity of the ring body 20 without entering the depth to the inside of 3A. As a result, good blowing performance can be realized.

(B) When the blade (3) tip (3C) is a rear inclined blade (3B) inclined rearward in the rotational direction

In this case, for example, as shown in FIG. 60, the blades 3 and 3B act in a direction where it is difficult to suck the circulation flow f ₂ formed by the ring body 20.

In addition, as shown by the symbol 6B in FIG. 59, even when the inner diameter D ₀ of the air intake port 6 of the bell mouse 5 is made small, the strong circulation flow f ₂ causes the blade 3, ( It circulates smoothly in the vicinity of the ring body 20 without going deeply inside 3B). As a result, good blowing performance can also be realized.

  It is excellent in mass production and cost reduction, and it is applicable to the low noise and high efficiency centrifugal blower and the air conditioner provided with the centrifugal blower.

Claims (20)

The hub 2 to which the rotating shaft 4a of the motor 4 is connected to the shaft center part, and the outer peripheral part of the hub 2 are installed at predetermined intervals along the circumferential direction, and the leading edge 3a is moved forward in the rotation direction. A centrifugal blower comprising an impeller (1) consisting of a plurality of blades (3) inclined toward the air, and a bell mouse (5) having an air inlet (6) on an air intake side of the impeller (1). Configured to form a circulating flow f ₂ which passes from the blowout side of the impeller 1 to the back side of the air inlet 6 at the bell mouse 5 and is again sucked into the impeller 1, Ring bodies 9 and 20 having a predetermined width in the centrifugal direction are attached to the axial distal end of the blade 3 in the impeller 1, When the centrifugal width of the ring body 20 is set to H and the outer diameter of the blade 3 in the impeller 1 is set to D ₂ , it is set to be 0.05 <ki = H / D ₂ <0.225. Centrifugal blower. The hub 2 to which the rotating shaft 4a of the motor 4 is connected to the shaft center part, and the outer periphery part of the hub 2 are installed at predetermined intervals along the circumferential direction, and the leading edge 3a is forwardly rotated and A bell mouse 5 having an impeller 1 made up of a plurality of blades 3 which are not inclined in any direction behind the rotational direction, and having an air inlet 6 on the air intake side of the impeller 1. A centrifugal blower formed by placing a circulating flow (f ₂ ) which is sucked into the impeller (1) again from the blowout side of the impeller (1) through the back side of the air inlet (6) at the bell mouth (5). Configure it to form Ring bodies 9 and 20 having a predetermined width in the centrifugal direction are attached to the axial distal end of the blade 3 in the impeller 1, When the centrifugal width of the ring body 20 is set to H and the outer diameter of the blade 3 in the impeller 1 is set to D ₂ , it is set to be 0.05 <ki = H / D ₂ <0.225. Centrifugal blower. The method according to claim 2, Centrifugal blower, characterized in that the entire blade (3) in the impeller (1) is inclined along the rotational direction. The method according to claim 2, Centrifugal blower, characterized in that the entire blade (3) in the impeller (1) is inclined in the opposite side to the direction of rotation. The method according to claim 1 or 2, Centrifugal blower, characterized in that the tip of the blade (3) in the impeller (1) is inclined along the rotational direction. The method according to claim 1 or 2, Centrifugal blower, characterized in that the tip of the blade (3) in the impeller (1) is inclined in the opposite side to the direction of rotation. The method according to any one of claims 1 to 4, When the inner diameter of the air inlet 6 at the bell mouse 5 is D ₀ , the inner diameter of the blade 3 at the impeller 1 is D ₁ , and the outer diameter of the blade 3 is D ₂ , A centrifugal blower characterized in that 0 <(D ₀ -D ₁ ) / (D ₂ -D ₁ ) <0.6 is set. The method according to any one of claims 1 to 4, When the inner diameter of the air inlet 6 at the bell mouse 5 is D ₀ , the inner diameter of the blade 3 at the impeller 1 is D ₁ , and the outer diameter of the blade 3 is D ₂ , Centrifugal blower, characterized in that the set so that -0.3 <(D ₀ -D ₁ ) / (D ₂ -D ₁ ) <0.3. delete delete The method according to any one of claims 1 to 4, The blower of the impeller (1), the centrifugal blower characterized in that the inclined flow diffuser (23) for guiding the blowout air flow from the impeller (1) to the rear side inclined. The method according to any one of claims 1 to 4, A centrifugal blower characterized in that an inclined flow centrifugal diffuser (23) is provided on the take-out side of the impeller (1) to guide the take-out air flow from the impeller (1) in an oblique direction from the rear side to the centrifugal direction. The method according to any one of claims 1 to 4, A centrifugal blower characterized in that a distribution space (S) through which the circulation flow (f ₂ ) can pass is formed on the outer circumferential side of the air inlet (6) in the bell mouse (5). The method according to any one of claims 1 to 4, A centrifugal blower characterized in that B / D _2? 0.113 when the exit height of each blade (3) in the impeller (1) is B and the outer diameter of the blade (3) is D ₂ . The method according to any one of claims 1 to 4, A centrifugal blower characterized in that the outer diameter (D ₃ ) of the hub (2) constituting the impeller (1) is set smaller than the outer diameter (D ₂ ) of each of the blades (3). The method according to claim 15, A centrifugal blower characterized in that B / D _2? 0.08 when the exit height of each blade (3) in the impeller (1) is B and the outer diameter of the blade (3) is D ₂ . The method according to any one of claims 1 to 4, Centrifugal blower, characterized in that the number of blades (3) in the impeller (1) is 5 to 15 sheets. The method according to any one of claims 1 to 4, Centrifugal blowers, characterized in that the number of blades (3) in the impeller (1) is 20 to 50 sheets. The method according to any one of claims 2 to 4, Centrifugal blower, characterized in that the number of blades (3) in the impeller (1) is 30 to 72 sheets. An air conditioner formed by arranging a heat exchanger (15) and a blower (X) in a ventilation path (14) formed in a casing (13), and as the blower (X), the centrifuge according to any one of claims 1 to 4. The air conditioner which adopted the blower.

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