CN1112653A

CN1112653A - Cross flow fan assembly

Info

Publication number: CN1112653A
Application number: CN95101568A
Authority: CN
Inventors: 陈深元
Original assignee: Gold Star Co Ltd
Current assignee: LG Electronics Inc
Priority date: 1994-02-08
Filing date: 1995-02-08
Publication date: 1995-11-29
Anticipated expiration: 2015-02-08
Also published as: KR950025283A; KR970009834B1; CN1078683C

Abstract

An improved cross flow fan set reduces favorably the voiced noises like the paddle frequency noises in the fan and comprises a streamline front grille cover provided with a plurality of ventilation openings, a radiator positioned in the predetermined inner part of the front grille cover, a stabilizing bracket formed in the predetermined inner part of the front grille cover, a streamline rear-set guiding element integrated with the front grille cover and positioned on the predetermined back of the front grille cover and a cylinder impeller provided with a rotating axis. The circumference angle of the impeller is divided into a scheduled number of groups, each of which consists respectively of a plurality of paddle blades provided with different paddle angles.

Description

Cross flow fan assembly

The present invention relates to a kind of cross-flow fan group, relate to a kind of improved cross-flow fan group that can advantageously reduce the sound noise as propeller blade frequency (BPF) noise specifically.

Usually, air conditioner shown in the cross sectional view of Fig. 1 comprises: many be roughly fairshaped before the ventilated port 3 of processing on the grill cover 1, a radiator 2 that is contained in the predetermined inside of preceding grill cover 1, with a cylinder impeller 4, it is installed in radiator 2 behinds and has a rotating shaft 4a who joins thereon.As shown in Figure 2, the blade of blade angles such as being of predetermined number is arranged on the cylinder impeller 4, thereby blade angle is defined as the eccentric angle that forms between each blade.

In addition, steady rest 6 predetermined inside of being fitted in this preceding grill cover 1 is used for its space, place is divided into an exhaust area and an air-breathing district.A streamlined back guiding element 5 forms one and is used for guiding substantially the cooling air flow of discharging impeller 4 in its rear portion shaping with preceding grill cover 1.

In the accompanying drawing, reference number 7 is expressed the immediate position of distance between impeller 4 and the back guiding element 5, and reference number 8 is expressed the immediate position of distance between impeller 4 and the steady rest 6, the blade of reference number 9 expression impellers 4.

The air of being brought into by the wheel power of impeller 4 is being cooled during by radiator 2 shown in arrow among Fig. 1.

After this, the air of cooling is discharged into the air conditioner outside by the guiding of back guiding element 5 and steady rest 6.

But, when cooling air by

impeller

4 and 5 of the guiding elements in back approximated position and pass through impeller 4 and during the approximated position of 6 of steady rests, because the blade angle between each blade sheet is identical, then the noise frequency that is produced by the blade sheet in impeller 4 rotation processes does not only cancel each other out but complements each other and cause sound noise.

This noise periodically occurs, and the plotted curve in Fig. 4 has partly been represented concrete propeller blade frequency noise with the highest mensuration criteria for noise.

Yet according to the current trend of making usually as the cross-flow fan of air conditioner, the complete machine size is compact and require high-powerly not reduce its various performances with cross-flow fan high pressure more.

As shown in Figure 5A and 5B, in a kind of trial that reduces the BPF noise, general cross-flow fan group is by several air exhausting devices 10, and they can be described as the impeller section that vertically is divided into predetermined length along it.Air exhausting device 10 is located such that each device rotates 3 °-4 ° respectively along the impeller axis, but by this way noise of failing to obtain to effectively reduce.

In addition, overcome in the trial of noise problem, increased the distance of

impeller

4 and 5 of the guiding elements in back at another, and the distance of 6 of impeller 4 and steady rests, but the working efficiency of impeller 4 is greatly diminished in this case.

Therefore, the purpose of this invention is to provide a kind of cross-flow fan group.Another object of the present invention provides a kind of improved cross-flow fan group that can advantageously reduce the propeller blade frequency noise.

To achieve these goals, the cross-flow fan group that is provided comprises a preceding grill cover of streamline of offering many ventilating holes; A radiator that is installed in the predetermined inside of preceding grid; Predetermined inner center rest that is shaped at preceding grid; Guiding element after the streamline that is shaped with preceding grill cover unitary moulding and at its predetermined rear portion; With a cylindric impeller that is fitted with a rotating shaft, wherein the angle of circumference of impeller is divided into the grouping of predetermined number, is made up of some blades with different blade angle configurations respectively for every group.

Below accompanying drawing is made brief description.

Fig. 1 is the viewgraph of cross-section of the structure of the common air conditioner of expression;

Fig. 2 is side view that is contained in the impeller on the common air conditioner of expression;

Fig. 3 is that in detail expression is contained in the blade sheet on the impeller of common air conditioner and the viewgraph of cross-section of blade angle thereof;

Fig. 4 is the noise frequency characteristic plotted curve of expression according to the impeller of common technology;

Fig. 5 A is the viewgraph of cross-section of expression by the impeller of current techique;

Fig. 5 B is perspective view by the impeller of current techique of expression;

Fig. 6 is that expression in detail is according to the blade sheet of impeller of the present invention and the viewgraph of cross-section of blade angle thereof;

Fig. 7 is the plotted curve of expression according to the noise frequency characteristic of impeller of the present invention;

Fig. 8 is that expression is by the accumulation angle of the impeller blade sheet of the first embodiment of the present invention and the form of unequal interval;

Fig. 9 is that expression is by the accumulation angle of the impeller blade sheet of second embodiment of the invention and the form of unequal interval.

Several groupings are to have the structure identical with common cross-flow fan to the first embodiment of the present invention except the angle of circumference of cylinder impeller is divided into, thus each grouping also difference of blade angle that different blade angles and each one piece blade arranged.

Fig. 6 for example understands the several blade sheets in a certain grouping according to the present invention.Mark off each grouping and blade sheet in a grouping also is configured to different predetermined blade angle " a1, a2 ... an " and makes the noise frequency " NZ=(360 that is produced by each blade sheet by wheel rotation by different blade angles ^*The number of blade/blade angle) has nothing in common with each other.

Therefore, because frequency has been offset in compensation in it, then effectively reduce based on the BPF noise shown in the test result of Fig. 7.

At this moment, each blade angle θ G that divides into groups calculates by following formula, supposes that at first these groupings are divided into p moiety.

θ G=θ i ± △ θ G ... formula (I)

θ i=G in the formula ^*(360 °/P)

I/360 ° of △ θ G=ASin(2 π N θ) ... formula (II)

△ θ G is a G grouping blade angle variable herein, A=constant, N=periodicity.

For example, if whole impeller is made up of 35 blades, this angle of circumference is divided into five parts (p=5) makes every part that 7 blades and supposition A=5 be arranged, N=1, θ 1=72 herein, θ 2=144, or the like, by being worth substitution formula I accordingly and the formula II obtains following result.

△Θ1＝5sin（2π ^＊1 ^＊72/360°）＝4.755，

△Θ2＝5sin（2π ^＊1 ^＊144/360°）＝2.939，

△Θ3＝5sin（2π ^＊1 ^＊216/360°）＝-2.939，

△Θ4＝5sin（2π ^＊1 ^＊288/360°）＝-4.755，

△Θ5＝5sin（2π ^＊1 ^＊360/360°）＝0

Therefore, can obtain following result and be used for each grouping.

Grouping Θ i Θ G △ Θ G Θ G+1-Θ G

1 72.000 76.755 4.755 76.755

2 144.000 146.939 2.939 70.184

3 216.000 213.061 -2.939 66.122

4 288.000 283.245 -4.755 70.184

5 360.000 360.000 0 76.755

Simultaneously, to each blade angle (a1, the a2 of the blade in a certain grouping ... an) calculate by following formula, initial supposition is divided into the grouping of P moiety, and each several part has the B degree.

An=θ j ± △ an ... formula (III)

θ j=B/(P in the formula ^*N)

△ an=ASin(2 π N θ j/B) ... formula (IV)

△ an is " n " individual blade blade angle variable herein, and A: constant, N: periodicity.

If each branch is assembled with seven blades (P=7) and makes B=72 and supposition A=1, N=2, substitution is worth the result below formula III and IV can obtain accordingly.

△Θ1＝sin[2π ^＊2 ^＊（72/7 ^＊1）/72]＝0.975，

△Θ2＝sin[2π ^＊2 ^＊（72/7 ^＊2）/72]＝-0.434，

△Θ3＝sin[2π ^＊2 ^＊（72/7 ^＊3）/72]＝-0.782，

△Θ4＝sin[2π ^＊2 ^＊（72/7 ^＊4）/72]＝0.782，

△Θ5＝sin[2π ^＊2 ^＊（72/7 ^＊5）/72]＝0.434，

△Θ6＝sin[2π ^＊2 ^＊（72/7 ^＊6）/72]＝-0.975，

△Θ7＝sin[2π ^＊2 ^＊（72/7 ^＊7）/72]＝0

Therefore, can obtain being used for the following result of each grouping blade sheet.

The grouping I

Blade Θ j α n △ α n α n+1-α n

1 10.965 11.940 0.975 11.940

2 21.930 21.496 -0.434 9.556

3 32.895 32.113 -0.782 10.617

4 43.860 44.642 0.782 12.529

5 54.825 55.259 0.434 10.617

6 65.790 64.815 -0.975 9.556

7 76.755 76.755 0 11.940

Grouping II

Blade Θ j α n △ α n α n+1-α n

8 86.782 87.757 0.975 11.001

9 96.808 96.374 -0.434 8.617

10 106.834 106.052 -0.782 9.678

11 116.860 117.642 0.782 11.590

12 126.886 127.320 0.434 9.678

13 136.913 135.938 -0.975 8.617

14 146.939 146.939 0 11.001

Grouping III

Blade Θ j α n △ α n α n+1-α n

15 156.385 157.360 0.975 10.421

16 165.831 165.397 -0.434 8.037

17 175.277 174.495 -0.782 9.098

18 184.723 185.505 0.782 11.010

19 194.169 194.603 0.434 9.098

20 203.615 202.640 -0.975 8.037

21 213.061 213.061 0 10.421

Grouping IV

Blade Θ j α n △ α n α n+1-α n

22 223.087 224.062 0.975 11.001

23 233.114 232.680 -0.434 8.617

24 243.140 242.358 -0.782 9.678

25 253.166 253.948 0.782 11.590

26 263.192 263.626 0.434 9.678

27 273.219 272.244 -0.975 8.617

28 283.245 283.245 0 11.001

Grouping V

Blade Θ j α n △ α n α n+1-α n

29 294.210 295.185 0.975 11.940

30 305.175 304.741 -0.434 9.556

31 316.140 315.358 -0.782 10.617

32 327.105 327.887 0.782 12.529

33 338.070 338.504 0.434 10.617

34 349.035 348.060 -0.975 9.556

35 360.000 360.000 0 11.940

Simultaneously, second embodiment according to cross-flow fan of the present invention relates to a kind of impeller with many different separately from each other blade angles " a1, a2 ... an ".Different with first embodiment, the better simply aspect of second embodiment is that the impeller part is not divided into grouping.

At first, the blade blade angle of second embodiment's impeller " a1, a2 ... an " can represent that initial supposition is divided into the grouping of P moiety by following formula.

An=θ j ± △ an ... formula (V)

θ j=360(P in the formula ^* _n)

△ θ G=ASin(2 π N θ j/360) ... formula (VI)

In the formula △ an be n blade blade angle variable and

A: constant, N: periodicity

For example, if this impeller is made up of 35 blades, and suppose A=3.5, N=3 will be worth accordingly in substitution formula V and the VI and can get following result.

△α1＝3.5 ^＊sin[2π ^＊3 ^＊（360/35 ^＊1）/360]＝1.795，

△α2＝3.5 ^＊sin[2π ^＊3 ^＊（360/35 ^＊2）/360]＝3.082，

△α3＝3.5 ^＊sin[2π ^＊3 ^＊（360/35 ^＊3）/360]＝3.496，

Or the like.

Characteristic angle according to the blade sheet of the impeller of second embodiment of the invention is illustrated in the form of Fig. 9.

As mentioned above, according to cross-flow fan assembly of the present invention, as shown in Figure 7, reduced the impeller noise, BPF noise particularly, its means are to make impeller blade have different blade angles or the angle of circumference of impeller is divided into predetermined has different blade angles and the blade of configuration equal number in the grouping of each different blade angle.

Claims

1, a kind of cross-flow fan is characterized in that this unit comprises:

The preceding grill cover of streamline that offers many ventilated ports;

A radiator that is arranged on the predetermined inside of preceding grill cover;

Predetermined inner steady rest that forms at preceding grill cover;

After streamline guiding element with should before grill cover unitary moulding and be arranged on the predetermined rear portion of this preceding grid; And

The drum type impeller that rotating shaft is housed on it, the angle of circumference of this impeller is divided into the grouping with predetermined number, and the per minute group is made up of some blade sheets with different blade angles configurations respectively.

2, unit as claimed in claim 1 is characterized in that wherein said impeller is made up of at least two each air exhausting devices that are made of many blade sheets.

3, unit as claimed in claim 1 is characterized in that wherein each blade sheet (periodically) is configured to have predetermined angle.

4, unit as claimed in claim 1 is characterized in that wherein said blade angle calculates with a kind of sine function.

5, a kind of cross-flow fan group is characterized in that this unit comprises:

The preceding grill cover of streamline that offers many ventilated ports;

A radiator that is arranged on the predetermined inside of this preceding grill cover;

Predetermined inner steady rest that forms at this preceding grill cover;

One with should before grill cover form one and be arranged on the streamline at predetermined rear portion of this preceding grill cover after guiding element; And

The drum type impeller that rotating shaft is housed on it comprises some respectively by the blade sheets of the different assemblings of predetermined blade angle.

6, unit as claimed in claim 5 is characterized in that wherein said impeller is made up of at least two air exhausting devices that are made of many blade sheets respectively.

7, unit as claimed in claim 5 is characterized in that wherein each blade sheet periodically is configured to have predetermined angle.

8, unit as claimed in claim 5 is characterized in that wherein said blade angle calculates with a kind of sine function.