CN110005622B

CN110005622B - Axial flow fan

Info

Publication number: CN110005622B
Application number: CN201810010599.5A
Authority: CN
Inventors: 林仪汶; 吴志辉; 谢明凯
Original assignee: Delta Electronics Inc
Current assignee: Delta Electronics Inc
Priority date: 2018-01-05
Filing date: 2018-01-05
Publication date: 2021-08-06
Anticipated expiration: 2038-01-05
Also published as: CN110005622A

Abstract

The application relates to an axial flow fan, which comprises a fan frame, a supporting seat, an impeller, a first air resistance structure and a second air resistance structure. The fan frame is provided with an inner wall. The outlet air flow flows from the upper part of the impeller to the bottom along the outlet air direction. The first air resistance structure is provided with an outer edge part, an inner edge part and a connecting part which jointly define an air resistance space, the outer edge part extends from the outer edge of the connecting part and is connected with the inner wall, and the inner edge part extends from the inner edge of the connecting part and is parallel to the outer edge part. The second air resistance structure is arranged around the fan blade and is close to the inner edge part. The backward airflow generated by the rotation of the fan blade flows into the air resistance space and is blocked by the second air resistance structure. The third height from the connecting part to the bottom, which is connected with the inner edge part and the outer edge part, is greater than the second height from the top surface to the bottom of the second air resistance structure, and the second height is greater than or equal to the first height from the bottom surface to the bottom of the inner edge part.

Description

Axial flow fan

Technical Field

The present invention relates to an axial fan, and more particularly, to an axial fan capable of preventing a flow field from leaking at a back pressure and blocking an outflow of air flowing in a back direction.

Background

In the existing axial flow fan, as the back pressure caused by the operation of the axial flow fan rises, the leakage of the flow field from the clearance between the fan frame and the fan blade is more severe, and particularly, when the flow field has the maximum flow, the leakage of the air flow is also maximum.

The problem of flow field leakage often affects the performance of axial flow fans. Specifically, the air flow is diffused to generate not only extra noise, so that the operating decibel of the axial flow fan is increased, but also the operating efficiency of the axial flow fan itself is affected, and even the rotating speed must be increased to a great extent beyond expectation, so as to achieve the originally intended performance.

Therefore, how to develop an axial fan that can greatly block the leakage of the flow field and improve the operation efficiency is a problem to be solved.

Disclosure of Invention

It is a primary object of the present application to provide an axial fan that solves and ameliorates at least one of the problems and disadvantages of the prior art described above.

Another objective of the present application is to provide an axial fan, which can achieve the effects of reducing noise, improving the operation efficiency of the axial fan, and achieving high rotation speed at low rotation speed by means of the cooperation of the first air resistance structure and the second air resistance structure.

Another object of this application is to provide an axial fan, the air lock space that forms through first air lock structure for produced air current dorsad flows in the air lock space when axial fan's impeller drives the flabellum and rotates, and rethread second air lock structure blocks that the air spills over from this air lock space, can effectively prevent axial fan's flow field from leaking, and then reaches the flow field and flow field backward flow and promotes axial fan operating efficiency's effect.

In order to achieve the above objective, a preferred embodiment of the present invention provides an axial fan, which includes a fan frame, a supporting base, an impeller, at least one first air-blocking structure, and a second air-blocking structure. The fan frame has an inner wall. The supporting seat is arranged at the bottom of the fan frame. The impeller is axially arranged on the supporting seat and is provided with a plurality of fan blades, and when the plurality of fan blades are driven to rotate, the air outlet flow flows from the upper part of the impeller to the bottom part through the fan blades along the air outlet direction. Each first air resistance structure is provided with an outer edge part, an inner edge part and a connecting part, the outer edge part extends from the outer edge of the connecting part along the air outlet direction and is connected with the fan frame, the inner edge part extends from the inner edge of the connecting part along the air outlet direction, an air resistance space is defined by the outer edge part, the inner edge part and the connecting part together, and the backward airflow generated by the rotation of the fan blades flows into the air resistance space. The second air resistance structure is arranged around the fan blades and is adjacent to the inner edge part, and air is prevented from overflowing from the air resistance space. The length from the bottom surface of the inner edge part to the bottom part is a first height, the length from the top surface of the second air resistance structure to the bottom part is a second height, the length from the connecting part, which is connected with the inner edge part and the outer edge part, to the bottom part is a third height, the third height is greater than the second height, and the second height is greater than or equal to the first height.

In order to achieve the above objects, another preferred embodiment of the present invention provides an axial fan, which includes a fan frame, a supporting base, an impeller, at least one first air-blocking structure, and a second air-blocking structure. The fan frame has an inner wall. The supporting seat is arranged at the bottom of the fan frame. The impeller is axially arranged on the supporting seat and is provided with a plurality of fan blades, and when the plurality of fan blades are driven to rotate, the air outlet flow flows from the upper part of the impeller to the bottom part through the fan blades along the air outlet direction. Each first air resistance structure is arranged at the top of the fan frame, the first air resistance structures extend upwards and inwards from the top of the fan frame to form a groove, the notch of the groove faces the air outlet direction to form an air resistance space, and the backward airflow generated by the rotation of the fan blades flows into the air resistance space. The second air resistance structure is arranged around the fan blades and partially extends into the groove to prevent air from overflowing from the air resistance space.

In order to achieve the above objects, another preferred embodiment of the present invention provides an axial fan, which includes a fan frame, a supporting base, a first impeller, a second impeller, at least one first air-blocking structure, and a second air-blocking structure. The fan frame has an inner wall. The supporting seat is arranged in the fan frame. The first impeller is axially arranged on one side of the supporting seat and is provided with a plurality of first fan blades, and when the plurality of first fan blades are driven to rotate, first air outlet flow flows to the bottom from the upper part of the first impeller through the first fan blades along the air outlet direction. The second impeller is axially connected with the first impeller in series and arranged on the other side of the supporting seat, and when the plurality of second fan blades are driven to rotate, second air outlet flow flows from the upper part of the second impeller to the bottom part through the second fan blades along the air outlet direction. Each first air resistance structure is provided with an outer edge part, an inner edge part and a connecting part, the outer edge part extends from the outer edge of the connecting part along the air outlet direction and is connected with the fan frame, the inner edge part extends from the inner edge of the connecting part along the air outlet direction, an air resistance space is defined by the outer edge part, the inner edge part and the connecting part together, and the back airflow generated by the rotation of the plurality of first fan blades and the plurality of second fan blades flows into the air resistance space. The second air resistance structure is arranged around the second fan blades and is adjacent to the inner edge part, and air is prevented from overflowing from the air resistance space; the length from the bottom surface of the inner edge part to the bottom part is a first height, the length from the top surface of the second air resistance structure to the bottom part is a second height, the length from the connecting part, which is connected with the inner edge part and the outer edge part, to the bottom part is a third height, the third height is greater than the second height, and the second height is greater than or equal to the first height.

Drawings

Fig. 1 is a schematic view showing a distance relationship between blades and an inner wall of an axial flow fan according to the present invention.

Fig. 2A shows a schematic cross-sectional view of an axial flow fan according to a preferred embodiment of the present application.

Fig. 2B is a partially enlarged cross-sectional schematic view of the axial flow fan shown in fig. 2A.

Fig. 3 is a schematic structural view showing an impeller and a second air resistance structure of the axial flow fan according to the present invention.

Fig. 4 is a schematic cross-sectional view illustrating a fan frame, a support seat, and a first air resistance structure of an axial flow fan according to the present invention.

Fig. 5 shows a schematic top view of the axial flow fan shown in fig. 2A.

Fig. 6 is a schematic top view of an axial flow fan according to another preferred embodiment of the present application.

Fig. 7 shows a schematic cross-sectional view of an axial flow fan according to still another preferred embodiment of the present application.

Detailed Description

Some exemplary embodiments that embody the features and advantages of the present application will be described in detail in the following paragraphs. It is to be understood that the present application is capable of various modifications in various aspects without departing from the scope of the application, and that the description and drawings are to be taken as illustrative in nature and not restrictive.

Referring to fig. 1 to 3, fig. 1 is a schematic view illustrating a distance relationship between a blade and an inner wall of an axial flow fan according to the present application, fig. 2A is a schematic view illustrating a cross section of an axial flow fan according to a preferred embodiment of the present application, fig. 2B is a schematic view illustrating a cross section of an axial flow fan illustrated in fig. 2A, and fig. 3 is a schematic view illustrating a structure of an impeller and a second air blocking structure of an axial flow fan according to the present application. As shown in fig. 1 to 3, an axial flow fan 1 according to a preferred embodiment of the present application includes a fan frame 11, a support base 12, an impeller 13, at least one first air resistance structure 14, and a second air resistance structure 15. Wherein the fan frame 11 has an inner wall 111. The support base 12 is disposed at the bottom 112 of the fan frame 11. The impeller 13 is axially disposed on the support base 12 and has a plurality of blades 131. When the plurality of blades 131 are driven to rotate, for example, but not limited to, when the blades are driven by a motor installed on the support base 12 or other position in the fan frame 11 to rotate around the motor shaft as an axis, the outlet airflow flows from above the impeller 13 to the bottom 112 through the blades 131 along the outlet direction F, and the shortest distance between at least one of the blades 131 and the inner wall 111 during the rotation process is a fixed value. In other words, when the fan blades 131 are driven to rotate, the distance between the cylindrical swept surface generated by the rotation of the fan blades 131 and the inner wall 111 of the fan frame 11 is equal. The first air blocking structure 14 has an outer edge portion 141, an inner edge portion 142 and a connecting portion 143, the outer edge portion 141 extends from an outer edge of the connecting portion 143 along the air outlet direction F and is connected to the inner wall 111, and the inner edge portion 142 extends from an inner edge of the connecting portion 143 along the air outlet direction F and is parallel to the outer edge portion 141. The outer edge 141, the inner edge 142 and the connecting portion 143 together define an air blocking space S, and a backward airflow b generated by the rotation of the plurality of blades flows into the air blocking space S. The second air blocking structure 15 is disposed around the plurality of fan blades 131 and located in the air blocking space S, and is adjacent to the inner edge 142, and blocks air from overflowing from the air blocking space S. In some embodiments, the second air blocking structure 15 is disposed around the maximum outer diameter of the plurality of blades 131, or disposed at the end of the blades 131, but not limited thereto.

According to the idea of the present application, a length from the bottom surface of the inner edge portion of the first air resistance structure 14 to the bottom 112 of the fan frame 11 is a first height a, a length from the top surface of the second air resistance structure 15 to the bottom 112 of the fan frame 11 is a second height B, and a length from a connection portion 143 of the first air resistance structure 14, where the connection portion is connected to the inner edge portion 142 and the outer edge portion 141, to the bottom 112 of the fan frame 11 is a third height C, where the third height C is greater than the second height B, and the second height B is greater than or equal to the first height a.

In brief, according to the technical features of the foregoing embodiments, the axial flow fan 1 of the present application, by means of the cooperation of the first air resistance structure 14 and the second air resistance structure 15, and through the air resistance space S formed by the first air resistance structure 14, enables the backward airflow b generated when the impeller 13 drives the fan blade 131 to rotate to flow into the air resistance space S, and then the second air resistance structure 15 prevents the air from overflowing from the air resistance space S, so as to achieve the effects of reducing noise, improving the operating efficiency of the axial flow fan 1, and achieving high rotation speed at low rotation speed.

In addition, the distance between the inner edge 142 and the outer edge 141 of the first air resistance structure 14 is greater than the thickness of the second air resistance structure 15. In other words, the second air resistance structure 15 blocks part of the air resistance space S, particularly blocks a portion near the inner edge portion 142 in the air resistance space S, so that the backward air flow b can flow into the air resistance space S from the portion near the outer edge portion 141, but is not easily overflowed from the air resistance space S. Therefore, the flow field of the axial flow fan can be effectively prevented from leaking, and the effects of flow field backflow and improvement of the running efficiency of the axial flow fan 1 are achieved.

Furthermore, in the embodiment, the supporting base 12 is fixedly connected to the fan frame 11, and the first air resistance structure 14 and the fan frame 11 are two separate components, so the assembly sequence is to first dispose the impeller 13 on the supporting base 12, and then dispose the first air resistance structure 14 on the fan frame 11. In other embodiments, the supporting base 12 is detachably disposed on the fan frame 11, and the first air-blocking structure 14 and the fan frame 11 can be integrally formed, so that the impeller 13 can be inserted into the fan frame 11 through the opening of the bottom 112 of the fan frame 11 after being disposed on the supporting base 12.

Referring to fig. 4 in conjunction with fig. 1 to 3, fig. 4 is a schematic cross-sectional view of a fan frame, a supporting base and a first air resistance structure of an axial flow fan according to the present application. As shown in fig. 1 to 4, the axial flow fan 1 of the present application may be described in the following manner to make the technology of the present application more easily understood and implemented: the axial fan 1 includes a fan frame 11, a support base 12, an impeller 13, at least one first air-blocking structure 14 and a second air-blocking structure 15, wherein the first air-blocking structure 14 can be, but is not limited to, a barb-shaped ring, and the second air-blocking structure 15 can be, but is not limited to, an annular sidewall. The fan frame 11 has an inner wall 111. The support base 12 is disposed at the bottom 112 of the fan frame 11. The impeller 13 is axially disposed on the support base 12 and has a plurality of blades 131. When the plurality of blades 131 are driven to rotate, the outlet airflow flows from above the impeller 13 to the bottom 112 through the blades 131 along the outlet direction F, and the shortest distance between at least one blade 131 and the inner wall 111 is a fixed value during the rotation process. Each first air-blocking structure 14 is disposed on the top portion 113 of the fan frame 11, the first air-blocking structure 14 extends upward and inward from the inner wall 111 to form a groove 140, preferably an inverted groove, and the width of the groove 140 is preferably greater than the thickness of the second air-blocking structure 15, but not limited thereto. The notch of the groove 140 faces the air outlet direction F to form an air blocking space S, and the backward airflow b generated by the rotation of the plurality of blades 131 flows into the air blocking space S. The second air blocking structure 15 is disposed around the plurality of fan blades 131 and partially extends into the recess 140 (or partially extends into the air blocking space S) to block air from overflowing from the air blocking space S.

Please refer to fig. 2A and fig. 4. Preferably, the connecting portion 143 of the first air resistance structure 14 of the axial fan 1 is parallel to the bottom 111 of the fan frame 11, in other words, the concave bottom 1401 of the groove 140 is parallel to the bottom 112 of the fan frame 11. In addition, in some embodiments, the inner wall 111 of the fan frame 11 has a first step 1111, the outer edge portion 141 of the first air resistance structure 14 has a second step 1411, and the first step 1111 and the second step 1411 are matched and fastened, so that the combination between the first air resistance structure 14 and the inner wall 111 of the fan frame 11 is more compact and is not easily detached by an external force.

Referring to fig. 5 and fig. 6 together with fig. 2A, fig. 5 is a schematic top view of the axial flow fan shown in fig. 2A, and fig. 6 is a schematic top view of an axial flow fan according to another preferred embodiment of the present application. As shown in fig. 2A, fig. 2B, fig. 5 and fig. 6, the number of the first air resistance structures 14 in the present application is not limited to one, and may be two or more, and as shown in the embodiment shown in fig. 6, the axial flow fan 1 in the present application includes six first air resistance structures 14, where the six first air resistance structures 14 are discontinuously distributed around the inner wall 111 of the fan frame 11. In addition, each outer edge 141 of each first air resistance structure 14 of the axial flow fan 1 of the present application is disposed corresponding to the same circumference with the axis of the impeller 13 as the center of the circle, and each inner edge 142 is disposed corresponding to the same circumference with the axis of the impeller 13 as the center of the circle, except that the circumference corresponding to the outer edge 141 is greater than the circumference corresponding to the inner edge 142.

Referring to fig. 7, a cross-sectional view of an axial flow fan according to another preferred embodiment of the present application is shown. As shown in fig. 7, the axial flow fan 2 of a preferred embodiment of the present application includes a fan frame 21, a support base 22, a first impeller 23, a second impeller 24, at least one first air-blocking structure 25 and a second air-blocking structure 26. Wherein the fan frame 21 has an inner wall 211. The support seat 22 is disposed in the fan frame 21. The first impeller 23 is axially disposed at one side of the supporting base 22 and has a plurality of first blades 231, wherein when the plurality of first blades 231 are driven to rotate, the first outlet airflow flows from above the first impeller 23 to the bottom 212 of the fan frame 21 through the first blades 231 along the outlet direction F, and the shortest distance between at least one first blade 231 and the inner wall 211 is a fixed value during the rotation process. The second impeller 24 is axially connected in series with the first impeller 23 on the other side of the support seat 22, wherein when the plurality of second blades 241 are driven to rotate, the second outlet airflow flows from above the second impeller 24 to the bottom 212 through the second blades 241 along the outlet direction F, and the shortest distance between at least one second blade 241 and the inner wall 211 in the rotation process is a fixed value. Each first air blocking structure 25 has an outer edge portion 251, an inner edge portion 252 and a connecting portion 253. The outer edge portion 251 extends from the outer edge of the connecting portion 253 along the air outlet direction F and is connected to the inner wall 211, the inner edge portion 252 extends from the inner edge of the connecting portion 253 along the air outlet direction F and is parallel to the outer edge portion 251, the inner edge portion 252 and the connecting portion 253 define an air blocking space S together, and the back airflow b generated by the rotation of the plurality of first blades 231 and the plurality of second blades 241 flows into the air blocking space S. The second air blocking structure 26 is disposed around the plurality of second blades 241, is located in the air blocking space S, is adjacent to the inner edge portion 252, and blocks air from overflowing from the air blocking space S.

According to the present disclosure, the length from the bottom surface of the inner edge portion 252 of the first air blocking structure 25 to the bottom 212 of the fan frame 21 is the first height X, the length from the top surface of the second air blocking structure 26 to the bottom 212 is the second height Y, and the length from the connecting portion 253 to the bottom 212 where the inner edge portion 252 and the outer edge portion 251 are connected is the third height Z. The third height Z is greater than the second height Y, and the second height Y is greater than or equal to the first height X.

It should be noted that the axial flow fan 2 in this embodiment includes two different impellers and they are connected in series, that is, the combination of the first air resistance structure and the second air resistance structure of the present application can be applied not only to the embodiment of the axial flow fan including a single impeller, but also to the embodiment of the axial flow fan including a plurality of impellers, which is highly flexible.

In summary, the present application provides an axial fan to solve and improve the problems and disadvantages of the prior art. By means of the cooperation of the first air resistance structure and the second air resistance structure, the effects of reducing noise, improving the running efficiency of the axial flow fan, achieving high rotating speed at low rotating speed and the like can be achieved. Particularly, through the air resistance space formed by the first air resistance structure, the back airflow generated when the impeller of the axial flow fan drives the fan blades to rotate flows into the air resistance space, and then the second air resistance structure prevents the air from overflowing from the air resistance space, so that the flow field of the axial flow fan can be effectively prevented from leaking, and the effects of backflow of the flow field and improvement of the running efficiency of the axial flow fan are achieved.

Although the present invention has been described in detail with reference to the above embodiments, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.

Description of the symbols

1 axial flow fan

11 fan frame

111 inner wall

1111 first stage difference

112 bottom

113 top part

12 support seat

13 impeller

131 flabellum

14 first air resistance structure

140 groove

1401 concave bottom surface

141 outer edge part

1411 second step difference

142 inner edge part

143 connecting part

15 second air resistance structure

2 axial flow fan

21 fan frame

211 inner wall

212 bottom part

22 support seat

23 first impeller

231 first fan blade

24 second impeller

241 second fan blade

25 first air resistance structure

251 outer edge portion

252 inner edge portion

253 connecting part

26 second air resistance structure

A first height

B second height

b backward air flow

C third height

F air-out direction

m shortest distance

S air resistance space

X first height

Second height of Y

Third height of Z

Claims

1. An axial flow fan comprising:

a fan frame having an inner wall;

a supporting seat arranged at the bottom of the fan frame;

an impeller, axially arranged on the supporting seat and provided with a plurality of fan blades, wherein when the plurality of fan blades are driven to rotate, the outlet air flow flows from the upper part of the impeller to the bottom part through the fan blades along an outlet air direction;

at least one first air resistance structure, wherein each first air resistance structure is provided with an outer edge part, an inner edge part and a connecting part, the outer edge part extends from the outer edge of the connecting part along the air outlet direction and is connected with the fan frame, the inner edge part extends from the inner edge of the connecting part along the air outlet direction and is parallel to the outer edge part, the inner edge part and the connecting part define an air resistance space together, and the back airflow generated by the rotation of the fan blades flows into the air resistance space; and

the second air resistance structure is arranged around the fan blades and is adjacent to the inner edge part, and shields the part, close to the inner edge part, in the air resistance space so as to prevent air from overflowing from the air resistance space;

the length from the bottom surface of the inner edge part to the bottom part is a first height, the length from the top surface of the second air resistance structure to the bottom part is a second height, the length from the connecting part, which is connected with the inner edge part and the outer edge part, to the bottom part is a third height, the third height is greater than the second height, and the second height is greater than the first height.

2. The axial fan according to claim 1, wherein the connecting portion of the first air resistance structure is parallel to the bottom portion of the fan frame.

3. The axial fan according to claim 1, wherein each of the inner edge portions is disposed corresponding to a same circumference centered on an axial center of the impeller.

4. The axial fan according to claim 3, wherein each of the outer peripheral portions is disposed corresponding to a same circumference centered on an axial center of the impeller.

5. The axial fan according to claim 1, wherein the number of the first air resistance structures is six, and the six first air resistance structures are discontinuously distributed around the inner wall.

6. The axial fan according to claim 1, wherein the second air resistance structure is provided around the maximum outer diameter of the plurality of fan blades.

7. The axial fan according to claim 1, wherein the second air resistance structure partially protrudes into the air resistance space.

8. The axial fan according to claim 1, wherein a distance between the inner edge portion and the outer edge portion is larger than a thickness of the second air blocking structure.

9. The axial fan as claimed in claim 1, wherein the outer rim portion is connected to an inner wall of the fan frame, the inner wall has a first step, the outer rim portion has a second step, and the first step matches the second step.

10. An axial flow fan comprising:

a fan frame having an inner wall;

a supporting seat arranged at the bottom of the fan frame;

an impeller, axially arranged on the supporting seat and provided with a plurality of fan blades, wherein when the plurality of fan blades are driven to rotate, the outlet air flow flows from the upper part of the impeller to the bottom part through the fan blades along the outlet air direction;

at least one first air resistance structure, wherein each first air resistance structure is arranged at the top of the fan frame, the first air resistance structure extends upwards and inwards from the top of the fan frame to form a groove, the notch of the groove faces the air outlet direction, two side walls of the groove are parallel to construct an air resistance space, and the backward airflow generated by the rotation of the fan blades flows into the air resistance space; and

the second air resistance structure is arranged around the fan blades and partially extends into the groove, and shields the part, close to the inner side wall of the groove, in the air resistance space so as to prevent air from overflowing from the air resistance space.

11. The axial fan according to claim 10, wherein the first air resistance structure is a barb-shaped ring, and the second air resistance structure is an annular sidewall.

12. The axial fan according to claim 10, wherein the concave bottom surface of the groove is parallel to the bottom of the fan frame.

13. An axial flow fan comprising:

a fan frame having an inner wall;

a supporting seat arranged in the fan frame;

the first impeller is axially arranged on one side of the supporting seat and is provided with a plurality of first fan blades, and when the plurality of first fan blades are driven to rotate, first air outlet flow flows to the bottom of the fan frame from the upper part of the first impeller through the first fan blades along the air outlet direction;

the second impeller is axially connected with the first impeller in series and arranged on the other side of the supporting seat, and when the plurality of second fan blades are driven to rotate, second air outlet flow flows to the bottom from the upper part of the second impeller through the second fan blades along the air outlet direction;

at least one first air resistance structure, wherein each first air resistance structure is provided with an outer edge part, an inner edge part and a connecting part, the outer edge part extends from the outer edge of the connecting part along the air outlet direction and is connected with the fan frame, the inner edge part extends from the inner edge of the connecting part along the air outlet direction and is parallel to the outer edge part, the inner edge part and the connecting part jointly define an air resistance space, and the backward airflow generated by the rotation of the plurality of first fan blades and the plurality of second fan blades flows into the air resistance space; and

the second air resistance structure is arranged around the second fan blades and is adjacent to the inner edge part, and shields the part, close to the inner edge part, in the air resistance space so as to prevent air from overflowing from the air resistance space;

14. The axial fan according to claim 13, wherein a distance between the inner edge portion and the outer edge portion is larger than a thickness of the second air blocking structure.

15. The axial flow fan according to any one of claims 1, 10, or 13, wherein the first air resistance structure and the fan frame are an integrally formed structure.