CN103900167B - The air-out protective cover of blower fan, blower fan and air-conditioner outdoor unit - Google Patents

Abstract

The invention provides an air outlet protection cover of a fan, a fan and an outdoor unit of an air conditioner. The air outlet protective cover of the fan includes a plurality of warp strip groups, and the number of warp strips in the warp strip group is relatively prime to the number of blades; the projection of the windward side of the warp strips on the plane perpendicular to the rotation axis is Aki The curved section on the Mead spiral; the tangent of the windward side of the curved section on the windward side of the airfoil is parallel to the axis of the rotating shaft; the diameter of the wind wheel D1, the radial distance b from the wind wheel to the wind guide ring, The minimum distance m between the trailing edge of the blade and the radial surface on the air inlet side of the outermost ring of the air outlet protective cover and the diameter D2 of the radial surface on the air inlet side of the outermost ring of the air outlet protective cover satisfy {(D1+2b+0.53×m)× (1‑3%)}≤D2≤{(D1+2b+0.53×m)×(1+3%)}; the starting point of the Archimedes spiral coincides with the center of the latitudinal circle and is located at the center of the rotation axis On the axis, after the above conditions are met, the noise generated by the fan is reduced, and the dynamic pressure of the rotating flow generated by the fan is best recovered as static pressure, which improves the energy efficiency of the fan.

Description

Outlet protective cover of fan, outdoor unit of fan and air conditioner

technical field

The present invention relates to the field of electric appliances, and more specifically, relates to an air outlet protective cover of a fan, a fan including the air outlet protective cover, and an outdoor unit of an air conditioner including the fan.

Background technique

At present, the fan used for the outdoor unit of the air conditioner is generally a propeller fan, and the propeller fan is equipped with blades on the outer periphery of the hub, and can use the lift generated by the rotation of the blades to send air. At this time, compared with the vicinity of the hub on the blowing side, the spiral flow generated on the outer peripheral side of the blowing side of the propeller fan in the same direction as the fan rotation increases. If the spiral flow cannot be converted into the axial flow of the fan, that is, the axial flow , the dynamic pressure energy is lost, and the aerodynamic performance of the propeller fan is reduced. At the same time, the helical flow impacts on the safety protection grille of the fan, which increases the dynamic pressure loss of the fluid and generates noise. For this reason, there are following two solutions in the prior art:

The first method is: designing the safety protection grille as a safety protection grille with strips extending radially;

The second method is: the safety protection grille is designed as a grid-shaped safety protection grille composed of concentric strips and radially extending strips.

In the first method, since there are no concentric strips in the safety protection grille, in order to prevent foreign matter from entering the propeller fan from the outside, many radially extending strips are required, and the safety protection grille is designed However, due to the dense design of the safety grille, the rotating flow from the propeller fan will cause a lot of dynamic pressure loss and noise when passing through the safety grille.

In the second method, the safety protection grille is in a lattice shape composed of concentric strips and radially extending strips, but the lattice strips extend downstream parallel to the direction of the rotation axis of the propeller fan, Therefore, the swirling flow cannot be turned in the direction of the rotary axis, resulting in a loss of dynamic pressure energy and a decrease in aerodynamic performance.

Contents of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art.

Therefore, the purpose of the first aspect of the present invention is to provide an air outlet protective cover of a fan that can reduce the loss of mechanical pressure and the noise of the fan.

The object of the second aspect of the present invention is to provide a fan with the above-mentioned fan protection cover.

The object of the third aspect of the present invention is to provide an outdoor unit of an air conditioner having the above fan.

In order to achieve the above object, the embodiment of the first aspect of the present invention provides a wind outlet protective cover for a fan, comprising a weft loop ring and warp strips arranged radially along the weft loop ring, the warp strips of the warp strips The projection of the windward surface on a plane perpendicular to the rotation axis of the fan is a curved segment on the Archimedes spiral.

In the above-mentioned embodiment of the present invention, the projection of the windward surface of the warp strip on the plane perpendicular to the rotation axis of the fan is a curved segment on the Archimedes spiral (that is, a constant speed helix), and the blades of the fan rotate When , air flows in three directions: axial, radial and circumferential. When the projection of the windward side of the strip on the plane perpendicular to the rotation axis is a curved segment on the Archimedes spiral, on the one hand it can Reduce the turbulence generated when the flowing air encounters the strips, reduce the noise, and reduce the loss of dynamic pressure. At the same time, it is beneficial to use the dynamic pressure of the fan to generate the rotating flow (that is, the flow along the circumference) as the static pressure. Recycle.

To sum up, the wind outlet protective cover provided by the embodiment of the present invention, by setting the projection of the windward surface of the warp sheet on the plane perpendicular to the rotation axis of the fan to be a curved segment on the Archimedes spiral, on the one hand reduces the The turbulent flow generated when the small flow of air encounters the strips reduces the noise and reduces the loss of dynamic pressure. At the same time, the dynamic pressure of the fan to generate the rotating flow (that is, the flow along the circumference) is used as the recovery of the static pressure. The best results, improving the energy efficiency of the fan.

In addition, according to the above-mentioned embodiments of the present invention, the air outlet protective cover of the fan also has the following additional technical features:

According to an embodiment of the present invention, the wind outlet protection cover includes at least three weft rings and a plurality of warp sheet groups, the centers of at least three weft rings coincide and the radii are different, and each of the weft rings The warp strip sheet group all includes a plurality of said warp strip sheets, one said warp strip sheet group is arranged between every adjacent two said weft loop rings, and a plurality of said warp strip sheets of each said warp strip sheet group The sheets are radially arranged along the radial direction of the weft ring, the shape and size of a plurality of the warp sheets in the same group of warp sheets are the same, and the warp sheets in different groups of warp sheets are The shapes of the slices are different.

According to an embodiment of the present invention, curve segments obtained by projecting windward surfaces of the warp strip sheets in different warp strip sheet groups on a plane perpendicular to the rotation axis are located on the same Archimedes spiral.

According to an embodiment of the present invention, the starting point of the Archimedes spiral coincides with the center of the weft ring and is located on the axis of the rotating shaft.

According to an embodiment of the present invention, the tangent to the windward side of the windward side curved section of the warp strip airfoil of each warp strip is parallel to the axis of the rotation shaft.

According to an embodiment of the present invention, the number of the warp strips in each warp strip group and the number of blades of the fan are mutually prime numbers.

An embodiment of the second aspect of the present invention provides a fan, including: a fan body, the fan body includes a motor and a wind wheel, the wind wheel includes blades and a hub, and the blades are connected to the motor through the hub on the rotating shaft; and the wind outlet protective cover described in any one of the above embodiments, the air outlet protective cover is located on the air outlet side of the fan.

According to an embodiment of the present invention, the wind outlet protection cover further includes a wind guide ring, one end of the wind guide ring is sleeved outside the wind wheel, and the other end is connected to the wind outlet protection cover, and the wind guide ring The axis of the wind guiding ring and the axis of the rotating shaft are located on the same straight line, and there is a gap between the wind guiding ring and the blades.

According to an embodiment of the present invention, the diameter of the wind wheel is D1, the radial distance between the wind wheel and the wind guide ring is b, and the trailing edge of the blade and the outermost side of the wind outlet protection cover The minimum distance of the radial surface on the air inlet side of the circle is m, the diameter of the radial surface on the air inlet side of the outermost circle of the wind outlet protection cover is D2, and {(D1+2b+0.53×m)×(1- 3%)}≤D2≤{(D1+2b+0.53×m)×(1+3%)}.

The embodiment of the third aspect of the present invention provides an air conditioner, comprising: a casing, the casing is provided with an air outlet; a heat exchanger, the heat exchanger is arranged in the casing; and any of the above According to an embodiment of the fan, the fan main body of the fan is arranged in the casing and is located on the front side of the heat exchanger, and the air outlet side of the fan is facing the air outlet, and the fan is The air outlet protection cover is fixed on the housing and covers the air outlet.

Additional aspects and advantages of the invention will become apparent in the description which follows, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and comprehensible from the description of the embodiments in conjunction with the following drawings, wherein:

Fig. 1 is a schematic structural view of an air outlet protective cover according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of the curve segment obtained by projecting the windward surface of the warp sheet of the windshield shown in Fig. 1 on a plane perpendicular to the axis of rotation;

Fig. 3 is a schematic diagram of the drawing method of the Archimedes spiral;

Fig. 4 is a schematic structural view of the airfoil of the air outlet shield shown in Fig. 1;

Fig. 5 is a schematic structural diagram of a fan according to an embodiment of the present invention.

Wherein, the corresponding relationship between reference numerals and component names in Fig. 1 to Fig. 5 is:

1 air outlet protection cover, 10 weft rings, 11 warp strips, 110 warp strip airfoils,

111 through the windward side curve section of the strip airfoil,

112 through the tangent of the windward side curve section of the strip airfoil, 113 through the chord line of the strip airfoil,

114 curve segments projected on the plane perpendicular to the axis of rotation by the windward side of the sliver,

2 wind wheels, 3 wind guide rings, 4 motors, 40 rotating shafts, 400 rotating shaft axes,

41 plane perpendicular to the axis of rotation

detailed description

In order to understand the above-mentioned purpose, features and advantages of the present invention more clearly, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways than described here. Therefore, the protection scope of the present invention is not limited by the specific implementation disclosed below. Example limitations.

The following describes the wind outlet protective cover of the fan, the fan and the outdoor unit of the air conditioner according to some embodiments of the present invention with reference to the accompanying drawings.

As shown in FIG. 1 and FIG. 2 , according to some embodiments of the present invention, an air outlet protection cover 1 for a blower fan includes at least three weft rings 10 and a plurality of warp sheet groups.

Wherein, at least three of the weft rings 10 have the same centers and different radii. In the specific example shown in FIG. Strip sheet group, the radius difference of adjacent two weft circle rings 10 is equal;

As shown in Figure 1, each of the warp sheet groups includes a plurality of warp sheet groups 11, and one of the warp sheet groups is arranged between every two adjacent weft rings 10, and each of the A plurality of the warp strips 11 of the warp strip group are arranged radially along the radial direction of the weft ring 10; as shown in Figure 2, the windward side of the warp strips 11 is perpendicular to the fan The projected curve segment 114 on the plane of the axis of rotation is a curve segment on the Archimedes spiral.

In the above-mentioned embodiment of the present invention, the projection of the windward surface of the warp strip on the plane perpendicular to the rotation axis of the fan is a curved segment on the Archimedes spiral (that is, a constant speed helix), and the blades of the fan rotate When , air flows in three directions: axial, radial and circumferential. When the projection of the windward side of the strip on the plane perpendicular to the rotation axis is a curved segment on the Archimedes spiral, on the one hand it can Reduce the turbulence generated when the flowing air encounters the strips, reduce the noise, and reduce the loss of dynamic pressure. At the same time, it is beneficial to use the dynamic pressure of the fan to generate the rotating flow (that is, the flow along the circumference) as the static pressure. Recycle.

To sum up, the wind outlet protective cover provided by the embodiment of the present invention, by setting the projection of the windward surface of the warp sheet on the plane perpendicular to the rotation axis of the fan to be a curved segment on the Archimedes spiral, on the one hand reduces the The turbulent flow generated when the small flow of air encounters the strips reduces the noise and reduces the loss of dynamic pressure. At the same time, the dynamic pressure of the fan to generate the rotating flow (that is, the flow along the circumference) is used as the recovery of the static pressure. The best results, improving the energy efficiency of the fan.

Preferably, as shown in FIG. 1 , the multiple warp strip sheets 11 in the same warp strip sheet group have the same shape and size.

The shape and size of multiple warp strips in the same warp strip group are the same, which facilitates the mass production of warp strips on the one hand and reduces the production cost, and on the other hand facilitates the installation of warp strips in the same warp strip group.

In an embodiment of the present invention, as shown in FIG. 1 , the warp strip sheets 11 in different warp strip sheet groups have different shapes.

Specifically, the curve segments 114 obtained by projecting the windward surfaces of the warp strip sheets 11 in different warp strip sheet groups on a plane perpendicular to the rotation axis are located on the same Archimedes spiral.

The warp strips in each warp strip group provided in the embodiments of the present invention are all curved segments intercepted on the same Archimedes spiral, and the positions intercepted by the warp strips in the same warp strip group are the same, The shapes of the warp strips in the same warp strip group are the same, and the intercepted positions of the warp strips in different warp strip groups are different, so that the shapes of the warp strips in different warp strip groups are different. After cutting, the warp strips The warp strips in the sheet group are arranged in a circular array (the warp strips are rotated in the process of the circular array) with the center of the weft ring as the center.

As shown in Figure 2, the Cartesian coordinate system of the Archimedes spiral where the curve segment 114 is obtained by projecting the slice on the plane perpendicular to the axis of the rotation axis (that is, the XY plane) with the Z axis as the axis of rotation The equation is:

Among them, r represents the polar radius; θ represents the angle between the airfoil chord line of the blade and the plane 41 (that is, the XY plane in Fig. 2 ) perpendicular to the rotation axis 40; λ represents the polar angle of the Archimedes spiral, 0 ≤λ≤θ, used to control the shape and length of the Archimedes spiral, when λ=0, r=0, when λ=θ, r=D ₃ ; The angle of , 0≤φ≤2π, is used to control the angle of the rotation array of the curve segment 114 obtained through the slice projection.

Since it is difficult to accurately draw the Archimedes spiral, in actual engineering, the approximate drawing method is used to approximate the Archimedes spiral. The following provides an approximate drawing of the Archimedes spiral method, as shown in Figure 3:

(1) First draw a circle with O as the center and lead S as the radius (not shown in the figure), and then divide the circle and radius into the same n equal parts, n=8 in the figure;

(2) Take O as the center of the circle, make concentric arcs intersect with the radius of the corresponding number, and get the intersection points 1′, 2′, 3′, ... 8′, which are the points of the Archimedes spiral;

(3) Smoothly connect each point in turn to get the Archimedes spiral, which is the curve represented by the solid line in the figure.

In a specific embodiment of the present invention, the starting point of the Archimedes spiral (that is, the center O in FIG. 3 ) coincides with the center of the circle of latitude.

Further, the center of the latitude ring is located on the axis 400 of the rotating shaft 40 .

The starting point of the Archimedes spiral coincides with the center of the latitude ring, and the center of the latitude ring is located on the axis of the rotating shaft, that is, the starting point of the Archimedes spiral and the center of the latitude ring are both located on the axis of the fan's rotating shaft Above, the flowing air generated by the rotation of the blades of the fan will generate turbulent flow when it encounters the warp strips, and when the windward side of the warp strips is projected on a plane perpendicular to the rotation axis, the Archimede When the starting point of the German helix is located on the axis of the rotating shaft, it can reduce the degree of turbulence, reduce the dynamic pressure loss of the flowing air, and reduce the noise generated when the air hits the warp sheet.

In one embodiment of the present invention, as shown in Figure 1, the quantity of the described warp strip sheet 11 in different described warp strip sheet groups is different, the closer the warp strip in the warp strip sheet group of weft ring 1 edge The more the number of sheets 11 is, the larger the gap between two adjacent warp strip sheets 11 will be, otherwise it will not be able to prevent external objects from entering the inside of the fan.

In a preferred embodiment of the present invention, the number of the warp strips 11 in each warp strip group and the number of blades of the fan are mutually prime numbers.

In the specific example shown in Figure 1, the number of blades is 3, from the inside to the outside, the number of warp strips in the six warp strip groups is respectively 35, 50, 62, 73, 76, 76, and 35, 50, 62, 73 and 76 are all prime numbers to 3 (that is, 35, 50, 62, 73 and 76 have no common divisors with 3).

Noise will be generated when the blades cut the air, and noise will also be generated when the outflow of the external machine passes through the warp strips of the air outlet protection cover. These two noises will interfere. When the number of warp strips in the warp strip group Interference noise can be weakened when it is relatively prime to the number of blades of the fan.

In a preferred example of the present invention, as shown in FIG. 4 , the tangent 112 on the windward side of the curved section 111 on the windward side of each of the warp strip airfoils is parallel to the axis of rotation 40 Axis 400.

The axis-plane projection of the cross-section of the slivers taken by the rotating cylindrical surface with the axis 400 of the rotating shaft 40 as the center is called the slivers airfoil 110, and the connecting line between the midpoints of the guide circles at both ends of the sliver airfoils 110 is When the chord line 113 of the sliver airfoil and the tangent line of the windward side curve section of the sliver airfoil are parallel to the axis of the rotating shaft, the rotating flow generated by the rotation of the fan blades meets the windward side of the sliver. , flows along the windward side of the warp strip, because the tangent of the windward side of the windward side curve section of the warp strip airfoil is parallel to the axis of the rotation axis, so the rotating flow leaves from the windward side of the windward side and moves along the rotation axis The axial direction of the fan can be moved to realize the conversion of the rotating flow into the axial flow and improve the axial air supply effect of the fan.

The embodiment of the second aspect of the present invention provides a fan, as shown in FIG. 5 , including a fan main body and an air outlet protection cover 1 .

Specifically, the fan main body includes a motor 4 and a wind wheel 2, the wind wheel 2 includes blades and a hub, and the blades are connected to the rotating shaft 40 of the motor 4 through the hub;

The air outlet protection cover 1 is the air outlet protection cover of the fan described in any one of the above embodiments, and the air outlet protection cover 1 is located on the air outlet side of the fan.

The blower provided by the above-mentioned embodiments of the present invention includes a main body of the blower and the air outlet protective cover described in any one of the above-mentioned embodiments, and the air outlet protective cover is located on the air outlet side of the fan. The setting of the air outlet protective cover can prevent external On the other hand, it can reduce the noise generated by the fan and improve the energy efficiency of the fan.

In a specific embodiment of the present invention, as shown in FIG. 5 , the fan further includes a wind guide ring 3, one end of the wind guide ring 3 is sleeved outside the wind wheel 2, and the other end is connected to the outlet. The wind shield 1 is connected, and the axis of the wind guiding ring 3 and the axis 400 of the rotating shaft 40 are on the same straight line, and there is a gap between the wind guiding ring 3 and the blades.

Further, as shown in Figure 5, the diameter of the wind wheel 2 is D1, the radial distance between the wind wheel 2 and the wind guide ring 3 is b, the trailing edge of the blade and the wind protection The minimum distance of the radial surface on the air inlet side of the outermost ring of the cover 1 is m, the diameter of the radial surface on the air inlet side of the outermost ring of the wind outlet protective cover 1 is D2, and {(D1+2b+0.53×m )×(1-3%)}≤D2≤{(D1+2b+0.53×m)×(1+3%)}.

In the above-mentioned embodiments of the present invention, the diameter of the wind wheel (that is, the diameter of the circumscribed circle of the largest outer edge of the impeller) is D1, and the radial distance between the wind wheel and the wind guide ring (that is, the distance between the outer edge of the blade and the inner wall of the wind guide ring The single-sided radial distance) is b, the minimum distance between the trailing edge of the blade (that is, the edge on the blade opposite to the leading edge of the blade (the edge of the windward side of the blade)) and the radial surface of the outermost wind inlet side of the wind outlet protection cover If the distance is m, the diameter D2 of the radial surface on the air inlet side of the outermost ring of the air outlet protective cover can be calculated as: D2'=D1+2b+0.53×m, taking into account the arc guide and mold of the wind guide ring of the fan Due to processing errors and fan assembly errors, the diameter of the radial surface on the air inlet side of the outermost ring of the air outlet protection cover needs to be adjusted within a 3% error range. Therefore, the outermost ring of the air outlet protection cover The final value range of the diameter of the radial surface on the air inlet side is: D2'×(1-3%)≤D2≤D2'×(1+3%), namely (D1+2b+0.53×m)×( 1-3%)≤D2≤(D1+2b+0.53×m)×(1+3%). When the fan satisfies the above relational expression, the effect of recovering the dynamic pressure of the rotating flow generated by the fan as static pressure is improved, thereby improving the energy efficiency of the fan.

The embodiment of the third aspect of the present invention provides an outdoor unit of an air conditioner (not shown in the figure), including a casing (not shown in the figure), a heat exchanger (not shown in the figure) and any one of the above-mentioned The fan described in the example.

Wherein, the housing is provided with an air outlet (not shown in the figure);

The heat exchanger is arranged in the housing;

The fan main body of the fan is arranged in the housing and is located on the front side of the heat exchanger, and the air outlet side of the fan is facing the air outlet, and the air outlet protective cover of the fan is fixed to the on the housing and cover the air outlet.

The outdoor unit of the air conditioner provided by the above embodiments of the present invention includes the fan described in any of the above embodiments, and has all the beneficial effects of the fan described in any of the above embodiments. Therefore, the outdoor unit of the air conditioner provided by the embodiments of the present invention When working, the fan has low noise and high energy efficiency.

In summary, the blower fan provided by the present invention has the following characteristics: 1, the number of warp strips in each warp strip group is mutually prime with the number of blades of the fan; The projection on the plane of is the curve segment on the Archimedes spiral; 3. The tangent line of the windward side of the windward side curve segment of the strip airfoil is parallel to the axis of the rotating shaft; 4. The diameter D1 of the wind wheel, The unilateral radial distance b from the wind rotor to the wind guide ring, the minimum distance m between the trailing edge of the blade and the radial surface of the air inlet side of the outermost ring of the wind outlet protection cover, and the distance m between the radial surface of the outermost wind inlet side of the wind outlet protection cover Diameter D2 satisfies (D1+2b+0.53×m)×(1-3%)}≤D2≤{(D1+2b+0.53×m)×(1+3%)}; 5. Archimedes spiral The starting point coincides with the center of the weft ring and is located on the axis of the rotating shaft. After the above five conditions are met, the noise generated by the fan will be reduced, and the dynamic pressure can be recovered with the minimum damage to the gas flow, and the fan will generate a rotating flow. The dynamic pressure has the best recovery effect as the static pressure, which improves the energy efficiency of the fan.

In the description of the present invention, the term "plurality" refers to two or more; the terms "connection", "connection", "fixation" and the like should be understood in a broad sense, for example, "connection" can be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediary. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the description of this specification, descriptions of the terms "one embodiment", "some embodiments", "specific embodiments" and the like mean that specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in the present invention In at least one embodiment or example of . In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. the air-out protective cover of a kind of blower fan, it is characterised in that including：

Latitude circle ring；With

Along the latitude circle ring be radially arranged through silver, the windward side through silver is in the rotary shaft perpendicular to the blower fan The curved section being projected as on spiral of Archimedes in plane；

The air-out protective cover includes latitude circle ring described at least three and multiple through silver group, the circle of latitude circle ring described at least three The heart overlaps and radius is different, and each is described described through silver including multiple through silver group, equal per latitude circle interannular described in adjacent two Be provided with described in one through silver group, and it is each it is described through silver group it is multiple described through silver along the radial direction of the latitude circle ring in putting Penetrate shape arrangement, shape through silver of multiple described in the same group through silver, size are identical, in the difference groups through silver The shape through silver it is different, the quantity through silver in the different groups through silver is different, closer to the latitude The quantity through silver in the group through silver at ring edge is more.

2. the air-out protective cover of blower fan according to claim 1, it is characterised in that

The windward side through silver in the different groups through silver projects in the plane perpendicular to the rotary shaft and obtains Curved section be located at same spiral of Archimedes on.

3. the air-out protective cover of blower fan according to claim 2, it is characterised in that

The starting point of the spiral of Archimedes overlaps with the center of circle of the latitude circle ring, and on the axis of the rotary shaft.

4. the air-out protective cover of blower fan according to any one of claim 1 to 3, it is characterised in that

The tangent line of the air side of each windward side curved section through silver aerofoil profile through silver is parallel to the rotary shaft Axis.

5. the air-out protective cover of blower fan according to any one of claim 1 to 3, it is characterised in that

The quantity of the quantity through silver in each group through silver and the blade of blower fan prime number each other.

6. a kind of blower fan, it is characterised in that including：

Fan main body, the fan main body includes motor and wind wheel, and the wind wheel includes blade and wheel hub, and the blade passes through institute Wheel hub is stated to be connected in the rotary shaft of the motor；With

Air-out protective cover, the air-out protective cover be right 1 to 5 any one of blower fan air-out protective cover, it is described go out Wind protective cover is located at the air side of the blower fan.

7. blower fan according to claim 6, it is characterised in that also include：

Air-ducting ring, one end of the air-ducting ring is set in outside the wind wheel, and the other end is connected with the air-out protective cover, and described The axis of air-ducting ring is located along the same line with the axis of the rotary shaft, between having between the air-ducting ring and the blade Gap.

8. blower fan according to claim 7, it is characterised in that

A diameter of D1 of the wind wheel, the radial direction spacing between the wind wheel and the air-ducting ring is b, the trailing edge of the blade and institute The minimum range for stating the sagittal plane of air-out protective cover outmost turns inlet side is m, the footpath of the air-out protective cover outmost turns inlet side To a diameter of D2 in face, and { (D1+2b+0.53 × m) × (1-3%) }≤D2≤{ (D1+2b+0.53 × m) × (1+3%) }.

9. a kind of air-conditioner outdoor unit, it is characterised in that including：

Housing, air outlet is provided with the housing；

Heat exchanger, the heat exchanger is arranged in the housing；With

Blower fan as any one of claim 6 to 8, the fan main body of the blower fan is arranged in the housing, and position In the front side of the heat exchanger, and the blower fan air side just to the air outlet, the air-out protective cover of the blower fan is consolidated Determine onto the housing, and cover the air outlet.