CN1107808C

CN1107808C - Impeller of fan

Info

Publication number: CN1107808C
Application number: CN99105133A
Authority: CN
Inventors: 泉善树; 杉尾孝
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1998-04-14
Filing date: 1999-04-13
Publication date: 2003-05-07
Anticipated expiration: 2019-04-13
Also published as: EP0955469A3; EP0955469B1; MY123252A; CN1232143A; EP0955469A2; JP3204208B2; ES2230759T3; JPH11294389A

Abstract

An impeller of a fan includes hub (3) mounted with plural blades (2). The fan blows air by spinning the blades. A revolution locus of a leading edge (6) of blade (2) shows a valley in a portion between around a center and tip (8) of blade (2), and shows a peak in a portion between around the center and hub (3), with regard to windward. A cross sectional view of blade (2) in a radial direction shows a valley in a portion between around a center and tip (8), and shows a peak in a portion between around the center of blade (2) and hub (3). This structure realizes to lower the noise level and to increase the static pressure.

Description

Blast fan

The present invention relates to a kind of blast fan that is used for air conditioner etc., more specifically relate to the shape of impeller.

The temperature and humidity of air conditioner adjustable air, it generally includes an air-cooler, an air heater, a humidifier, a fan and an air filter.

Fig. 8 illustrates a kind of traditional mixed flow fan impeller 21 that is used for air conditioner.In this mixed flow fan, gas is with respect to the rotating shaft obliquely flow.

In Fig. 8, the impeller 21 of mixed flow fan has a plurality of slim vane 22, and they radially are installed on the wheel hub 23 that roughly is taper type.

Fig. 9 is the sectional view of cutting open along the D-D line of Fig. 8.Blade 22 cross section diametrically is a straight substantially line or one only towards the curve of a direction bending.Impeller 21 is contained in the same shell, and drives by being assemblied in rotating shaft in the wheel hub 23, that be connected in motor.Like this, impeller 21 is just by motor driving, thereby advertises air.

Yet, above-mentioned this conventional construction can't be controlled at the end of blade eddy current that is produced around blade 22 peripheral edge portions on the gratifying level in the air blast process, because the shape of cross section of blade 22 is a straight substantially line or one only towards the curve of a direction bending.

And blade 22 is without any the structure that can prevent that air-flow from radially sucking, and this air-flow produces when impeller 21 high loaies drive.

Therefore, need to improve as shown in Figure 8, the conventional impellers such as impeller 21, make it reduce noise by control end of blade eddy current, and suck gas flow smooth and realize bigger static pressure by making.

The present invention is intended to solve the above problems, and purpose is to provide a kind of more blast fan of low noise and bigger static pressure that has.

Therefore, the object of the invention is to provide a kind of like this blast fan, described impeller has a wheel hub that a plurality of blades are installed, and blade is rotated, advertise air with this, its characteristics are that the part of the rotating locus face of blade inlet edge between end of blade and blade middle part part is concavity with respect to the windward side, and the part between core and wheel hub is convex with respect to the windward side; The part of blade cross section radially between core and end of blade is concavity with respect to the windward side, and the part between core and wheel hub is convex with respect to the windward side.

Impeller of the present invention forms a rotating locus face in its leading edge.The shape of track plane and blade all is characteristics of the present invention.The track plane of the blade first half is concavity with respect to the windward side, and the track plane of blade Lower Half is convex with respect to the windward side.The blade first half is defined as around the part between blade middle part and the outer end, and the blade Lower Half is defined as around the part between blade middle part and the wheel hub.The radial cross-section of the blade first half is concavity with respect to the windward side, and the cross section of Lower Half is convex with respect to the windward side.

Above-mentioned shape can make impeller suppress the flow shedding blade.End of blade vortex system near the blade outer end the suction face is generated by the air-flow that overturns from pressure side towards suction face.Like this, the concavity curved section of blade can promote the generation of eddy current, thereby suppresses the flow shedding blade.Therefore, can obtain the lower fan of noise.Simultaneously, the convex curvature of blade part can make the air-flow that radially sucks more level and smooth when high load is worked, thereby increases static pressure.

Fig. 1 is the planimetric map of the blast fan of first representative embodiment of the present invention.

Fig. 2 is the part figure of blade rotating locus face of the blast fan of first representative embodiment of the present invention.

Fig. 3 is the sectional view of cutting open along A-A line among Fig. 1.

Fig. 4 shows the impeller of first representative embodiment of the present invention at work.

Fig. 5 is the impeller of first representative embodiment of the present invention and a kind of characteristic correlation curve figure of conventional impellers.

Fig. 6 is the stream centerline sectional view of the blade of second representative embodiment of the present invention.

Fig. 7 is the radial cross-section of thick of the blade of second representative embodiment of the present invention.

Fig. 8 is the planimetric map of a conventional fan impeller.

Fig. 9 is the sectional view that this conventional impellers is cut open along the D-D line of Fig. 8.

Representative embodiment of the present invention is described with reference to the accompanying drawings.

(representative embodiment 1)

To Fig. 5 first representative embodiment of the present invention is described below with reference to Fig. 1.

Fig. 1 is the planimetric map of a mixed flow fan impeller.Fig. 4 represents to be in the impeller of operating state.

In Fig. 1, mixed flow fan impeller 1 is installed on the wheel hub 3 that roughly is taper type, and it has three slim vane 2 that radially are positioned on the frustum outer rim.Arrow is represented sense of rotation.As shown in Figure 4, the wheel hub 3 that blade 2 is housed is fixed in the rotating shaft of motor 4, and impeller 1 is contained in the shell 5.Impeller 1 is by advertising air along arrow direction drive motor 4.At this moment, as shown in Figure 1, most of air-flow flows into the leading edge 6 of blade 2, and flows out from trailing edge 7.Impeller 1 is advertised air by this way.

Fig. 2 is the part figure of the blade 2 rotating locus faces of impeller 1.In Fig. 2, the rotating locus face that blade 2 leading edges 6 are marked half one and Lower Half thereon is concavity and convex with respect to the windward side respectively.The first half of blade 2 is defined as the part between blade middle part and outer end 8 (below be called " end of blade 8 "), and the Lower Half of blade 2 is defined as in the middle part of blade and the part between the wheel hub 3.The B-B line is divided into by the mid point that connects blade 2 leading edges 6 and trailing edge 7.The B-B line represents that air-flow is along the mobile stream center of direction shown in the arrow.The C-C line is represented the wheel hub center, i.e. the rotating center of impeller 1.

Fig. 3 is the sectional view of cutting open along the A-A line among Fig. 1.As shown in Figure 3, the radial cross-section 2 of blade 2 is concavity and convex with respect to the windward side respectively at the blade first half and Lower Half.The first half of blade 2 cross sections is defined as around the part between line B-B and the end of blade 8, and its Lower Half is defined as around the part between line B-B and the wheel hub 3.This structure can produce around the air-flow of end of blade 8 itself end of blade 8, this air-flow from the pressure side 10 of blade 2 towards its suction face upset.This air-flow produces the end of blade eddy current around end of blade 8 on suction face 9, the concavity curved section of blade 2 can promote the generation of this eddy current, thereby suppresses the flow shedding blade.Therefore, can obtain the lower impeller of noise 1.Simultaneously, the convex curvature of blade 2 part can make the air-flow that radially sucks that is more level and smooth from the air-flow of end of blade 8 side inflows when high load work, thereby the increase static pressure.

Equally, the present invention can reduce noise, and increases static pressure in impeller high loading working procedure.

The concrete advantage of first representative embodiment is described below.

Fig. 5 is the characteristic correlation curve figure of impeller of the present invention and a kind of conventional impellers.Employing blade external diameter is 400 millimeters a impeller in the experiment.Static pressure and noise characteristic with respect to air quantity are shown in this plotted curve.

As indicated in this experiment, the noise of impeller of the present invention is lower 2 decibels than conventional impellers at open air quantity point Q1 place.And the noise of impeller of the present invention keeps lower always till the Q2 point of advertising 68% open air quantity.About static pressure, impeller of the present invention rises 32% at the Q3 point place that advertises 60% open air quantity than conventional impellers.

(representative embodiment 2)

Below with reference to Fig. 6 and Fig. 7 second representative embodiment of the present invention described.

Fig. 6 is the sectional view that the longshore current of blade shown in Fig. 7 road center line B-B cuts open.Fig. 7 is the radial cross-section that blade is cut open at thick.As shown in Figure 6, the blast fan of second representative embodiment has wing blade.

The stream center line is drawn between the mid point of the leading edge of rotating locus face upper blade 12 and trailing edge.In this embodiment, blade 12 has following size: 5%≤t/c≤12% at stream center line B-B place,

Wherein, t=blade 12 is at the maximum ga(u)ge at B-B line place,

The leading edge of c=blade 12 and the distance between the trailing edge,

It is wing that blade is, and it has the leading edge and a sharp-pointed trailing edge of an arch.

And in this embodiment, the radial cross-section of blade 12 is concavity and convex with respect to the windward side respectively at the first half and Lower Half.The first half is defined as around the part between center line B-B and the end of blade 14, and Lower Half is defined as around the part between center line B-B and the wheel hub 13.

The concavity curved section that above-mentioned structure makes blade 12 is by air-flow 15 upsets and can promote generation at the suction face lateral lobe end eddy current of end of blade 14 from pressure side 16 towards suction face, thereby suppresses flow shedding blade 12.Therefore, can obtain the lower impeller of noise 11.

Simultaneously, the convex curvature of blade 12 partly makes the air-flow that radially increases suction when high load is worked, from the gas flow smooth of end of blade 14 side inflows, thereby increases static pressure.

Second representative embodiment shows that impeller 11 can be realized lower noise and bigger static pressure, and first representative embodiment also has same effect.

Compare with blade with constant thickness, the blade of second representative embodiment has the size such as 5%≤t/c≤12%, wherein: the t=maximum ga(u)ge, c=is across the width of blade between the mid point of leading edge and trailing edge, it is wing that blade is, it has an arch leading edge and a sharp-pointed trailing edge, thereby prevents the flow shedding blade more reliably.Therefore, can further reduce noise level.

Following result is that the low noise effect on the employed impeller provides in second representative embodiment by measuring:

The low noise effect begins and can be noted from t/c=5%, and reaches capacity at the t/c=12% place.Experiment shows, is 400 millimeters and is used under the situation of mixed flow fan at impeller outer diameter, and when adopting the blade shape of t/c=9%, noise level reduces by 2 decibels than the blade with constant thickness.

Technology of the present invention is not limited to the mixed flow fan impeller, and it also can produce identical effect in axial flow fan impeller, and axial flow fan impeller is meant that gas flows along rotating shaft in impeller.

Claims

1. blast fan, described impeller has one the wheel hub (3) of a plurality of blades (2) is installed, and makes blade (2) rotation, advertises air with this, it is characterized in that:

The part of the rotating locus face of blade (2) leading edge (6) between end of blade (8) and blade (2) core is concavity with respect to the windward side, and the part between core and wheel hub (3) is convex with respect to the windward side; And

The part of blade (2) cross section radially between core and end of blade (8) is concavity with respect to the windward side, and the part between core and wheel hub (3) is convex with respect to the windward side.

2. blast fan as claimed in claim 1 is characterized in that, the thickness of blade (2) is uniform.

3. blast fan as claimed in claim 1, it is characterized in that, the shape of cross section that blade (12) is cut open along extending to the stream center line of trailing edge (7) from leading edge (6) is made into, and the ratio of distance is from 5% to 12% between the maximum ga(u)ge of its stream center and preceding (6), trailing edge (7).

4. blast fan as claimed in claim 1, it is characterized in that, the shape of cross section that blade (12) is cut open along the stream center line that connects its leading edge (6) and trailing edge (7) is made into, 5%≤t/c≤12%, the maximum ga(u)ge of t=blade (12) wherein, c=is across the width of blade between the mid point of front and rear edges.

5. the described blast fan of each claim as described above is characterized in that described fan is a kind of mixed flow fan.