Air duct of axial flow fan

Abstract

The utility model relates to the technical field of fans, in particular to an axial flow fan ventilating duct which comprises an outer ventilating duct, a rear guide vane and an impeller, the rear guide vane and the impeller are coaxially arranged in the outer ventilating duct, an inner ventilating duct is arranged in a gap between the inner side of the outer ventilating duct and the impeller, the inner ventilating duct is coaxially arranged on the inner side of the outer ventilating duct, and the rear guide vane and the impeller are coaxially arranged in the outer ventilating duct. The outer side wall of the inner air guide cylinder is tightly attached to the inner side wall of the outer air guide cylinder, and the inner air guide cylinder is used for reducing the gap between the outer air guide cylinder and the impeller. When the air duct of the axial flow fan is used, the structure is simple, installation and operation are convenient, the performance of the fan is convenient to improve, meanwhile, the performance of the fan is remarkably improved under the condition that blades on an impeller are not changed, the manufacturing cost is low, and blade top leakage is reduced to the maximum extent.

Description

TECHNICAL FIELD

[0001] The utility model relates to a fan technical field especially relates to a axial flow fan air deflector. BACKGROUND

[0002] Fan is relied on the input mechanical energy, improves gas pressure and sends gas and it is a kind of driven fluid machinery. Fan is the habit of Chinese gas compression and gas conveying machinery, the fan usually includes ventilation machine, air blower, wind turbine.

[0003] Fan is widely used in factory, mine, tunnel, cooling tower, vehicle, ship and the ventilation, dust removal and cooling of building, the ventilation and air induction of boiler and industrial furnace;Cooling and ventilation in air conditioning equipment and household appliance equipment;Grain drying and selection, wind tunnel air source and air cushion ship inflation and propulsion etc.

[0004] The existing fan when using, to avoid the friction between the axial flow fan blade and the inner wall of air deflector, will keep certain size of tip clearance in fan design, in the tip clearance area, there is obvious flow separation and leakage vortex, influence fan performance. UTILITY MODEL CONTENT

[0005] The utility model provides a kind of axial flow fan air deflector to solve the technical problem that the tip clearance area of existing fan exists obvious flow separation and leakage vortex, influences fan performance.

[0006] To solve the above problems, the utility model provides a kind of axial flow fan air deflector adopts following technical scheme:

[0007] A kind of axial flow fan air deflector, including outer air deflector, rear guide vane and impeller coaxially arranged in outer air deflector, gap between the inner side of outer air deflector and impeller is equipped with inner air deflector, inner air deflector is coaxially arranged in the inner side of outer air deflector, the outer side wall of inner air deflector and the inner side wall of outer air deflector are close together, and inner air deflector is used to reduce the gap between outer air deflector and impeller.

[0008] Beneficial effect is: the utility model discloses a kind of axial flow fan air deflector, when using, first, inner air deflector is arranged in the inner side of outer air deflector, to reduce the gap between impeller and outer air deflector, in turn reduce the size of tip clearance area, finally reduce the phenomenon of flow separation and leakage vortex occurs. The utility model discloses a kind of axial flow fan air deflector, when using, simple structure, it is convenient to install and operate, it is convenient to improve the performance of fan, significantly improve fan performance without changing the blade on impeller, the production cost is lower, maximum limit reduces tip leakage.

[0009] Further, the thickness of inner air deflector is 1mm, 2mm or 3mm.

[0010] Further, with the axis direction of the outer air duct as the up-down direction, the upper end of the outer air duct is provided with a first turned edge, a plurality of first connecting holes are arranged on the first turned edge, the upper end of the inner air duct is provided with a second turned edge, a plurality of second connecting holes corresponding to the first connecting holes are arranged on the second turned edge, and the first connecting holes and the second connecting holes are screw holes and are detachably connected together through bolts.

[0011] Beneficial effects: simple structure, convenient installation and disassembly.

[0012] Further, the rear guide vane comprises radial gratings and a circumferential grating, the radial gratings are radially outwardly radiated along the outer air duct, the circumferential grating comprises a plurality of cylinder groups connected to the radial gratings and having different diameters, and the deflection direction of the radial gratings is opposite to the rotation direction of the impeller.

[0013] Beneficial effects: the radial gratings and the circumferential grating both have the flow guiding effect, and the effect of the fan is improved.

[0014] Further, the number of the radial gratings is 2 to 2.5 times of the number of the blades of the impeller, and the number of the radial gratings and the number of the blades of the impeller are co-prime.

[0015] Further, the tangent of the maximum point of the convexity of the radial grating and the vertical line is within the range of 15 degrees to 25 degrees.

[0016] Beneficial effects: the performance of the fan is improved.

[0017] Further, the angle between the extension line of the circumferential grating and the horizontal line is within the range of 70 degrees to 85 degrees.

[0018] Beneficial effects: the performance of the fan is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description read in conjunction with the accompanying drawings. In the drawings, several embodiments of the present application are illustrated by way of example and not limitation. Like or corresponding reference numerals primarily designate the same or corresponding parts throughout the drawings, in which:

[0020] Figure 1 Structure diagram of the axial flow fan air duct of the present application Figure 1 ;

[0021] Figure 2 Structure diagram of the axial flow fan air duct of the present application Figure 2 ;

[0022] Figure 3 Bottom view of the axial flow fan air duct of the present application

[0023] Figure 4 Figure 1 is a sectional view of the axial flow fan air guide tube according to the present application;

[0024] Figure 5 For Figure 4 Figure 1 is a sectional view of the axial flow fan air guide tube according to the present application;

[0025] Reference signs:

[0026] 1, outer air guide tube; 2, rear guide vane; 3, impeller; 4, inner air guide tube; 5, first turning edge; 6, second turning edge; 7, bolt; 8, radial grid; 9, circumferential grid. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It should be known by those skilled in the art that the embodiments described below are part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0028] Any number of elements in the drawings is used for illustration, not limitation, and any naming is only used for distinction, not having any limiting meaning.

[0029] The principles and spirits of the present application will be explained in detail below with reference to several representative embodiments of the present application.

[0030] Embodiment 1 of the axial flow fan air guide tube provided by the present application:

[0031] As shown in Figures 1 to 5 The axial flow fan air guide tube provided by the present application comprises an outer air guide tube 1, a rear guide vane 2, an impeller 3 and an inner air guide tube 4.

[0032] The axial direction of the outer air guide tube 1 is taken as the up-down direction, and the upper end of the outer air guide tube 1 is provided with a first turning edge 5, and a plurality of first connecting holes are formed on the first turning edge 5 and arranged at intervals in the circumferential direction, and the first connecting holes are threaded holes.

[0033] The impeller 3 is coaxially arranged on the inner side of the outer air guide tube 1.

[0034] The rear guide vane 2 comprises radial grids 8 and circumferential grids 9, the radial grids 8 are radially outwardly radiated from the outer air guide tube 1, the circumferential grids 9 comprise a plurality of tubes of different diameters connected to each radial grid 8, and the deflection direction of the radial grid 8 is opposite to the rotation direction of the impeller 3.

[0035] The number of radial grids 8 is 2 to 2.5 times the number of blades of the impeller 3, and the number of radial grids 8 and the number of blades of the impeller 3 are co-prime.

[0036] The angle between the tangent of the maximum point of the radial grid 8 convex camber and the vertical line ranges from 15 degrees to 25 degrees.

[0037] The angle between the extension line of the circumferential grid 9 and the horizontal line ranges from 70 degrees to 85 degrees.

[0038] The thickness of the inner air duct 4 is 2mm, and the upper end of the inner air duct 4 is provided with a second turned edge 6, a plurality of second connecting holes corresponding to each first connecting hole are formed in the second turned edge 6, and the second connecting holes are threaded holes.

[0039] The first connecting hole and the second connecting hole are detachably connected together through the bolt 7.

[0040] The axial flow fan air duct of the utility model in use, first, the inner air duct 4 is arranged in the inner side of the outer air duct 1, thereby reducing the gap between the impeller 3 and the outer air duct 1, and further reducing the size of the blade tip gap area, and finally reducing the phenomenon of flow separation and leakage vortex.

[0041] The axial flow fan air duct of the utility model in use, simple structure, convenient installation and operation, convenient for improving the performance of the fan, and significantly improving the performance of the fan without changing the blade on the impeller, lower manufacturing cost, and maximum reduction of blade tip leakage.

[0042] The embodiment 2 of the axial flow fan air duct provided by the utility model:

[0043] The difference between the embodiment 1 mainly lies in that:

[0044] In the embodiment 1, the thickness of the inner air duct is 2mm.

[0045] In the embodiment, the thickness of the inner air duct can also be 1mm or 3mm.

[0046] The embodiment 3 of the axial flow fan air duct provided by the utility model:

[0047] The difference between the embodiment 1 mainly lies in that:

[0048] In the embodiment 1, the upper end of the outer air duct is provided with a first turned edge, a plurality of first connecting holes are arranged on the first turned edge, the upper end of the inner air duct is provided with a second turned edge, a plurality of second connecting holes corresponding to each first connecting hole are formed in the second turned edge, and the first connecting hole and the second connecting hole are threaded holes and can be detachably connected together through the bolt.

[0049] In the embodiment, the inner air duct and the outer air duct are interference fit, and in use, the inner air duct is knocked into the outer air duct by knocking.

[0050] According to the above description of the present specification, those skilled in the art can also understand that the terms used such as "upper", "lower", "front", "rear", "left", "right", "width", "horizontal", "top", "bottom", "inner", "outer" and the like indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings of the present specification, which are only for the purpose of facilitating the description of the scheme of the present application and simplifying the description, and are not explicitly or implicitly indicated that the devices or elements involved must have the specific orientation, be constructed and operated in a specific orientation, therefore the above orientation or positional relationship terms cannot be understood or interpreted as a limitation on the scheme of the present application.

[0051] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed methods and technical contents to obtain equivalent embodiments with equivalent changes, without departing from the scope of the technical scheme of the present application. Any simple modification, equivalent change and modification of the above embodiments made according to the technical essence of the present application still belongs to the scope of the technical scheme of the present application.

[0052] In addition, in the description of the present specification, the meaning of "a plurality of" is at least two, such as two, three or more, etc., unless otherwise explicitly and specifically limited.

Claims

1. An axial flow fan duct comprising an outer duct, a back vane and an impeller coaxially arranged in the outer duct, characterized in that, The gap between the outer air guide cylinder and the impeller is provided with an inner air guide cylinder, the inner air guide cylinder is coaxially arranged in the inner side of the outer air guide cylinder, the outer side wall of the inner air guide cylinder is tightly attached to the inner side wall of the outer air guide cylinder, and the inner air guide cylinder is used for reducing the gap between the outer air guide cylinder and the impeller.

2. A ducted axial fan according to claim 1, wherein The thickness of the inner air guide cylinder is 1 mm, 2 mm or 3 mm.

3. The ducted axial fan of claim 1 wherein: The axis direction of the outer air guide cylinder is the up-down direction, the upper end of the outer air guide cylinder is provided with a first turning edge, a plurality of first connecting holes are arranged on the first turning edge, the upper end of the inner air guide cylinder is provided with a second turning edge, a plurality of second connecting holes corresponding to the first connecting holes are arranged on the second turning edge, the first connecting holes and the second connecting holes are threaded holes and are detachably connected together through bolts.

4. The ducted axial fan of any one of claims 1 to 3, wherein the fan wheel is mounted on a shaft, and the shaft is mounted on a bearing. The rear guide vane comprises radial grates and circumferential grates, the radial grates are radially outwardly radiated, the circumferential grates comprise a plurality of cylinders with different diameters connected to the radial grates, and the deflection direction of the radial grates is opposite to the rotation direction of the impeller.

5. A ducted axial fan according to claim 4, wherein the fan housing is formed from a plurality of substantially planar panels which are joined together to form the fan housing. The number of the radial grates is 2 to 2.5 times of the number of the blades of the impeller, and the number of the radial grates and the number of the blades of the impeller are co-prime.

6. A ducted axial fan according to claim 4, wherein The tangent of the maximum point of the radial grate convexity and the vertical line is in the range of 15 degrees to 25 degrees.

7. A ducted axial fan according to claim 4, wherein The angle between the circumferential grate extension line and the horizontal line is in the range of 70 degrees to 85 degrees.

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