EP2716915A1 - Housing for an axial ventilator - Google Patents

Abstract

The housing has an outer diffuser (6) formed from two partial ring sections, which are connected at an outer circumferential surface by a mechanical connecting unit. A holder is formed from multiple bars (14), which are fastened at an inner circumferential surface of the outer diffuser with an end and circumferentially spaced at a distance from each other. The bars are fastened in an edge region of an inflow opening (7). The bars are mounted at a motor flange (16) of a motor housing (17) of an electric motor (9) with another end. An inner diffuser (26) is arranged within the outer diffuser. The outer diffuser is made of plastic.

Description

The present invention relates to a housing for a fan or fan, in particular for an axial fan, comprising a wall ring with an inlet nozzle portion and an outflow connected thereto annular diffuser with an inflow opening and an outflow opening and a holder for an electric motor of the fan, in an interior of the housing is arranged.

In such known cases, see US 2,144,035 , the diffuser is produced as a sheet metal part, resulting in relatively high production costs, however, and also has the known solution, especially in the middle and lower pressure range relatively poor efficiencies and a high noise level.

The present invention is based on the object, on the one hand to achieve a cost reduction and on the other hand to improve the efficiency and noise in the middle and lower pressure range.

According to the invention this is achieved in that the outer diffuser is formed from at least two partial ring sections, which are connected by means of mechanical connection means on its outer peripheral surface, and the holder of a plurality on one inner peripheral surface of the diffuser with one end attachable, circumferentially spaced, in the edge region of its inflow opening fastenable struts exist with their other end a motor flange of a motor housing of the electric motor can be mounted. Advantageously, the outer diffuser is formed from four partial ring sections and four equidistant struts are provided, which are formed in particular from two parallel spokes. In particular, the outer diffuser according to the invention consists of plastic, and the mechanical connection of the individual partial ring sections takes place by means of screws or rivets or by plug connections. Due to the multi-part nature of the outer diffuser, the tool costs are reduced. Furthermore, it is advantageous if the outer diffuser expands conically from its inflow opening to its outflow opening with a cone angle α relative to its center axis XX of 10 ° to 18 °, in particular 12 ° to 15 °. The course of the peripheral wall of the diffuser can be made both straight and curved from the inflow opening to the outflow opening. In this case, it is advantageous according to the invention if the diffuser has a height measured in the direction of the longitudinal axis XX above vanes of the axial fan arranged in the wall ring, which is greater than / equal to 200 mm to 800 mm, with a ratio of L: D1 of 0.25 to 1.0, preferably 0.25 to 0.8, where L is the height of the outer diffuser measured in the direction of the longitudinal axis XX above the blades arranged in the wall ring and D1 is the diameter of the inflow opening. This inventive design of the efficiency of the housing according to the invention and the noise is achieved in particular in the middle and lower pressure range.

Furthermore, the invention provides that within the outer diffuser centric to its central axis an inner diffuser is arranged, which extends from the inflow opening to the outflow opening and having a closed peripheral wall, and which is connectable in the region of the inflow opening with the motor flange of the motor housing of the electric motor. Here, the inner diffuser has in the connection region for the motor flange a circumferential wall with a circular flow cross-section and forms an annular section, which in an air duct section with a polygonal, in particular square cross-section, in particular with rounded corners, passes. Starting from the annular section, this air guiding section has an interior which widens toward the opposite end.

The inventive arrangement and design of the inner diffuser prevents a hub backflow and optimizes the efficiency. According to the invention, it is also advantageous if in a direction perpendicular to the longitudinal axis X-X extending opening plane of the outer diffuser in the region of the outflow opening a circular protective grid is arranged, which is connected with its outer peripheral edge with the outer diffuser. Here, according to the invention, the inner diffuser is also connected to the protective grid by a cover on the protective grid on its outflow-facing side rests a cover that is so releasably connected to the Luftleitabschnitt of the inner diffuser fastening means that the protective grid between the end cover and the air guide is included. The protective grid according to the invention preferably has square meshes. Here is a large mesh size, for example, from 30 mm to a maximum of 40 mm, in square mesh advantage. By supporting the protective grille on the inner diffuser a "walkability" of the housing according to the invention is ensured.

Fig. 1

eine perspektivische Ansicht von oben auf ein erfindungsgemäßes Gehäuse mit darin befindlichem Elektromotor mit montiertem Lüfterrad,

Fig. 2

einen Schnitt entlang der Schnittlinie II-II in Fig. 1,

Fig. 3

eine perspektivische Ansicht von unten auf einen erfindungsgemäßen Außendiffusor mit montiertem Elektromotor und Axiallüfterrad,

Fig. 4

eine Einzelheit bei IV in Fig. 2,

Fig. 5

eine perspektivische Ansicht eines erfindungsgemäßen Innendiffusors ohne Abschlussdeckel und

Fig. 6

eine Teilansicht einer weiteren Ausführungsform eines erfindungsgemäßen Gehäuses.

Advantageous embodiments of the invention are contained in the subclaims and will be explained in more detail with reference to the embodiments illustrated in the accompanying drawings. Show it:

Fig. 1

a perspective view from above of an inventive housing with befindlichem electric motor with mounted fan,

Fig. 2

a section along the section line II-II in Fig. 1 .

Fig. 3

a perspective view from below of an outer diffuser according to the invention with mounted electric motor and axial fan,

Fig. 4

a detail at IV in Fig. 2 .

Fig. 5

a perspective view of an interior diffuser according to the invention without end cap and

Fig. 6

a partial view of another embodiment of a housing according to the invention.

In the Fig. 1 to 6 the same parts or functionally identical parts are always identified by the same reference numerals. If certain described and / or removable from the drawings features of the housing according to the invention or its components are described only in connection with an embodiment, but these are also essential according to the invention regardless of this embodiment as a single feature or in combination with other features of the embodiment and are claimed as belonging to the invention.

As is clear from the Fig. 1, 2 and 3 In particular, there is an inventive housing for an axial fan 1 of a wall ring 2 with an inlet nozzle section 3, which is made in particular of metal. This inlet nozzle section 3 encloses a suction channel 4, which is circular in cross-section. An annular outer diffuser 6 is connected to the wall ring 2 at the free end of the inlet nozzle section 3 and has an in particular circular inflow opening 7 and an in particular circular outflow opening 8. The flow direction of a medium to be transported through the housing by means of the axial fan 1 is indicated by Z. The axial fan 1 consists of an electric motor 9 with which a paddle wheel 11 is drivingly connected. The outer diffuser 6 preferably consists of at least two partial ring sections 12, wherein in the illustrated embodiment, four partial annular sections 12 are shown, which by means of mechanical connection means 13 to an outer Peripheral surface of the outer diffuser 6 are interconnected. Each partial ring section 12 extends over a specific peripheral region, so that in the fully assembled state the partial annular sections 12 are connected to form a circumferentially closed annular section. The outer diffuser 6 is advantageously made of plastic and the connecting means 13 may be, for example, screws, rivets or a latching connection. Furthermore, the housing according to the invention has a holder of at least three struts 14, which circumferentially have mutually equal distances. These struts 14 are fastened in the edge region of the inflow opening 7 on the inner peripheral surface of the outer diffuser 6. At its other end, the struts 14 can be fastened to a motor flange 16 of the electric motor 9 or a housing 17 of the electric motor 9.

In particular Fig. 2 it can be seen, the outer diffuser 6 has a height L measured in the direction of the longitudinal axis XX above arranged in the wall ring 2 and the inlet nozzle section 3 blades of the blade wheel 11, which is greater than / equal to 200 mm to 800 mm inclusive. Here, a ratio of L / D1 of 0.25 to 1.0, in particular 0.25 to 0.8 is provided, wherein D1 is the diameter of the inflow opening 7 of the outer diffuser 6. The outer diffuser 6 widens conically from its inflow opening 7 to its outflow opening 8 with a cone angle α of 10 ° to 18 °, in particular 12 ° to 15 °, relative to its center axis XX.

Furthermore, it is off Fig. 4 to recognize that the outer diffuser 6 has on its outer side in the region of the inflow opening 7 corresponding to the number of struts 14, ie in the present embodiment, four mounting portions 18. These mounting portions 18 are outwardly flared at an angle γ between 90 ° and 90 ° + α and have at their free end an angled portion 19. This bend 19 extends at an angle β to the longitudinal axis XX. This bend 19 abuts against a tab 21, which is formed on the ends of the struts 14 and also arranged at the angle β to the longitudinal axis XX is. The angle β must be ≥ 90 ° + α (α = cone angle). For attachment of the outer diffuser 6 to the struts 14, the bend 19 is bolted to the respective associated tab 21, for example by means of a screw 22. At the same time the wall ring 2 is screwed with a radially projecting annular collar 23 via a screw to the tab 21. As a result of this design of the attachment regions 18, subsequent assembly or disassembly of the complete system without a wall ring is provided Fig. 3 possible without having to remove the items.

und die Formel $$\mathrm{\Delta }{A}_i=A_{2i}-A_{1i}=\pi \times \left(d_1+k\times L\right)\times \left(k\times L\right)$$

ermittelt wird und die so ermittelte Austrittsfläche A_2i des Luftleitabschnitts 29 sich max. um 20% vom ermittelten Optimalwert unterscheidet, wobei A_1i die Öffnungsfläche des Innendiffusors zu Beginn seines Abschnitts 28 ist, und A_2i die Öffnungsfläche des Innendiffusors an seinem am Schutzgitter 36 angrenzenden Ende. Vorteilhafterweise besitzt der Luftleitabschnitt 29 abgerundete Ecken 32. In diesen Ecken 32 sind Anschlussdome 33 mit Einschraublöchern vorgesehen. Wie aus Fig. 2 ersichtlich ist, ist der Innendiffusor 26 derart bemessen, dass in seinem Innenraum das Motorgehäuse 17 des Elektromotors 9 aufgenommen werden kann. Zum Befestigen des Innendiffusors 26 an dem Motorflansch 16 weist der Innendiffusor 26 an dem dem Motorflansch 16 zugekehrten Ende des ringförmigen Abschnitts 28 radial nach innen weisende Befestigungslaschen 34 auf. Mit diesen Befestigungslaschen 34 kann der Innendiffusor 26 an dem Motorflansch 16 beispielsweise mittels Schrauben befestigt werden.How to continue the Fig. 1 to 3 and 5 can be seen, inside the outer diffuser 6, an inner diffuser 26 is arranged. The arrangement of the inner diffuser 26 is centric to the longitudinal axis XX. The inner diffuser 26 extends from the inflow opening 7 to the outflow opening 8 and has a closed circumferential wall 27. In the region of the inflow opening 7, the inner diffuser 26 can be connected to the motor flange 16 of the motor housing 17. For this purpose, the inner diffuser 26 in the connection region with the motor flange 16 has a circular cross-section, annular portion 28 with the inner diameter d ₁ , which merges into an air duct 29 with a particular square cross-section. As far as the design of the outer diffuser 6 and the inner diffuser 26 is concerned, moreover, it is fully applicable to the WO 2012/084725 A1 Referenced. Starting from the annular section 28, the air guide section 29 has an exit surface A _{2i which} changes in relation to the section 28, wherein the optimum surface change ΔA _{i corresponds} to its entry surface A _1i via an expansion _factor k $$k=\left(\frac{\sqrt{{\left({\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="imgf0001.png"\; state="\{\{state\}\}">D</figure-callout>}}_1+2\times L\times \tan \alpha \right)}^2-\left({{\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="imgf0001.png"\; state="\{\{state\}\}">D</figure-callout>}}_1}^2-{{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="imgf0001.png"\; state="\{\{state\}\}">d</figure-callout>}}_1}^2\right)\times \left(\frac{L}{D_1}-0.45\times {\left(\frac{\mathrm{<figure-callout\; id="1"\; label="L\; D"\; filenames="imgf0001.png"\; state="\{\{state\}\}">L\; </figure-callout>}}{D_{}}\right)}^2+1\right)}-{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="imgf0001.png"\; state="\{\{state\}\}">d</figure-callout>}}_1}{2\times L}\right)$$

and the formula $$\mathrm{\Delta }{A}_i=A_{2i}-{\mathrm{<figure-callout\; id="1"\; label="A"\; filenames="imgf0001.png"\; state="\{\{state\}\}">A</figure-callout>}}_{1i}=\pi \times \left({\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="imgf0001.png"\; state="\{\{state\}\}">d</figure-callout>}}_1+k\times L\right)\times \left(k\times L\right)$$

is determined and the thus determined exit area A _{2i of} the Luftleitabschnitts 29 max. _{Ai is} the opening area of the inner diffuser at the beginning of its section 28, and A _{2i is} the opening area of the inner diffuser at its end adjacent to the protective grille 36. Advantageously, the Luftleitabschnitt 29 has rounded corners 32. In these corners 32 Anschlußdome 33 are provided with screw holes. How out Fig. 2 it can be seen, the inner diffuser 26 is dimensioned such that in its interior, the motor housing 17 of the electric motor 9 can be accommodated. For fixing the inner diffuser 26 to the motor flange 16, the inner diffuser 26 has fixing lugs 34 pointing radially inward at the end of the annular section 28 facing the motor flange 16. With these fastening tabs 34, the inner diffuser 26 can be attached to the motor flange 16, for example by means of screws.

Furthermore, the Fig. 1 to 4 can be seen that in a direction perpendicular to the longitudinal axis XX extending opening plane of the discharge opening 8, a circular protective grid 36 is arranged, which is connected with its outer peripheral edge 37 with the outer diffuser 6 in the edge region of its discharge opening 8. This can be a screw connection. The protective grid 36 is formed from individual grid wires 38 which are arranged in a crosswise manner so as to form quadrangular, preferably square meshes 39. The mesh size, ie the distance between the parallel running grid wires 38 is 30 mm to a maximum of 40 mm. The outer diffuser 6 has, in its peripheral region encompassing the discharge opening 8, recesses 41 which are adapted to the contour of the grid wires 38, so that the grid wires 38 are received in these recesses 41. The protective grid 36 faces radially inside projecting mounting tabs which cooperate with formed on the inside of the outer diffuser 6 attachment lugs 42 and are connected by screws, which are screwed into the mounting lugs 42, with the outer diffuser 6.

Furthermore, it can be seen that the inner diffuser 26 has a cover cover 43 which rests on the protective grid 36 on its outflow-facing side and is releasably connected to the air guide 29 via fastening means, such as screws, that the protective grid 36 between the end cover 43rd and the air guide portion 29 is included. To fasten the end cover 43 by means of screws, the connection domes 33 serve in the corners 32 of the inner diffuser 26, in which the screws are screwed through the end cover 43 into the connection domes 33. For receiving the protective grid 36 with its grid wires 38 in the edge region of the air guide section 29, this likewise has recesses 44 which are adapted to the shape and size of the grid wires 38.

Furthermore, it can be seen that the inner diffuser 26 has bulges 46 projecting into the diffuser interior in the region of its annular section 28. Through the channels formed by the bulges 46 extend the spokes of the struts 14 in the assembled state, so that the outer wall portion of the inner diffuser 26 is not interrupted by the struts 14, but also forms a closed wall surface in this area.

In Fig. 6 a further embodiment of a housing according to the invention is shown in partial view. In this case, the wall ring 2 projects with its inlet nozzle section 3 into the outer diffuser 6 through its inflow opening 7, so that an overlapping area between the inlet nozzle section 3 and the outer diffuser 6 is present in the region of its section adjoining the inflow opening 7. As a result, an axial gap 47 is formed between these two parts, through the air from the outside into the interior of the outer diffuser 6 can occur. As a result of the overlap or overlap, the air entering through the axial gap 47 flows parallel to the air conveyed in the diffuser interior, so that there is no flow running transversely to the conveyed air, which could result in disturbing turbulences.

As in particular from Fig. 3 can be seen, the inventive design of the housing allows that the outer diffuser 6, the inner diffuser 26, the protective grid 36 and the struts 14 can be prefabricated with the consisting of electric motor 9 and paddle wheel 11 axial fan 1 as a unit. This unit can then be fixed on site with an already preassembled wall ring 2.

The invention is not limited to the illustrated and described embodiments, but also includes all the same in the context of the invention embodiments. Furthermore, the invention has hitherto not been limited to the feature combinations defined in the claims, but may also be defined by any other combination of specific features of all individual features disclosed overall. This means that in principle virtually every individual feature of the independent claims can be omitted or replaced by at least one individual feature disclosed elsewhere in the application. In this respect, the claims are to be understood merely as a first formulation attempt for an invention.

LIST OF REFERENCE NUMBERS

1

Axial

2

wall ring

3

Inlet nozzle section

4

intake port

6

diffusor

7

inflow

8th

outflow

9

electric motor

11

paddle wheel

12

Partial ring sections

13

connecting means

14

pursuit

16

motor flange

17

Housing of the electric motor 9

18

fixing areas

19

angling

21

flap

22

screw

23

gorget

26

internal diffuser

27

Wall section / peripheral wall

28

annular section

29

air guide

31

wall surfaces

32

corners

33

Dome connection

34

mounting tabs

36

guard

37

circumferential edge

38

gridwires

39

mesh

41

recesses

42

fastening lugs

43

connection cover

44

recesses

46

bulges

47

axial gap

Z

flow direction

L

height

X X

longitudinal axis

D1

Diameter of 7

α

cone angle

β

mounting brackets

γ

Angulation mounting area

d ₁

Diameter inner diffuser at the beginning of the annular portion 28th

A _1i

Surface of the inner diffuser at the beginning of the annular portion 28th

A _2i

Surface of the inner diffuser at its end adjacent to the protective grid 36 end

Claims (18)

Housing for a fan or fan, in particular axial fan (1), comprising a wall ring (2) with an inlet nozzle section (3) and an annular outer diffuser (6) connected to the wall ring (2) with an inflow opening (7) and an outflow opening ( 8) and a holder for an electric motor (9) of the fan (1), which is arranged in an inner space of the housing,
characterized in that the outer diffuser (6) is formed of at least two partial ring portions (12) connected to its outer peripheral surface by mechanical connecting means (13), and the plurality of holders to an inner peripheral surface of the outer diffuser (6) having one end fastened, circumferentially spaced, in the edge region of its inflow opening (7) attachable struts (14) is formed, which are mounted with their other ends to a motor flange (16) of a motor housing (17) of the electric motor (9). Housing according to claim 1,
characterized in that the outer diffuser (6) consists of four partial ring sections (12) is formed. Housing according to claim 1 or 2,
characterized in that four spaced struts (14) are present, each consisting in particular of two parallel spokes. Housing according to one of claims 1 to 3,
characterized in that the outer diffuser (6) from its circular cross-section inflow opening (7) to its circular cross-section discharge opening (8) conically with a centered on its Longitudinal axis (XX) related cone angle (α) of 10 ° to 18 °, in particular 12 ° to 15 ° extended. Housing according to one of claims 1 to 4,
characterized in that the outer diffuser (6) is made of plastic. Housing according to one of claims 1 to 5,
characterized in that the outer diffuser (6) has a height (L) measured in the direction of the longitudinal axis (XX) above in the wall ring (2) arranged blades of the blade wheel (11) of the axial fan (1) which is greater than or equal to 200 mm including 800 mm, at a ratio L / D1 of 0.25 to 1.0, preferably 0.25 to 0.8, where D1 is the diameter of the inflow opening (7). Housing according to one of claims 1 to 6,
characterized in that inside the outer diffuser (6) an inner diffuser (26) is arranged, which extends from the inflow opening (7) to the outflow opening (8) and has a closed peripheral wall (27), and which in the region of the inflow opening (7 ) is connectable to the motor flange (16) of the motor housing (17). Housing according to claim 7,
characterized in that the peripheral wall (27) in the connecting region for the motor flange (16) has a circular cross-section annular portion (28) in an air duct (29) with a particular square cross-section, with its corners (32) preferably rounded are, passes. Housing according to claim 7 or 8,
characterized in that the air guide section (29) has, starting from the annular section (28), an exit face (A _2i ) changing to the opposite end, the optimum surface change (ΔA _i ) being to its entry _face (A _1i ) via an extension _factor (k) with $$k=\left(\frac{\sqrt{{\left(D_1+2\times L\times \tan \alpha \right)}^2-\left({D_1}^2-{d_1}^2\right)\times \left(\frac{L}{D_1}-0.45\times {\left(\frac{L}{D_1}\right)}^2+1\right)}-d_1}{2\times L}\right)$$

and the formula $$\mathrm{\Delta }{A}_i=A_{2i}-A_{1i}=\pi \times \left(d_1+k\times L\right)\times \left(k\times L\right)$$

is determined and the thus determined exit surface (A _2i ) of the Luftleitabschnitts (29) max. (A _1i ) is the opening area of the inner diffuser at the beginning of its section (28), and (A _2i ) the opening area of the inner diffuser at its end adjacent to the protective grille (36). Housing according to one of claims 7 to 9,
characterized in that in the interior of the inner diffuser (26), the motor housing (17) of the electric motor (9) is accommodated. Housing according to one of claims 1 to 10,
characterized in that in a direction perpendicular to the longitudinal axis (XX) extending opening plane of the discharge opening (8) a protective grid (36) is fixed, which is connected with its outer peripheral edge (37) with the outer diffuser (6). Housing according to one of claims 1 to 11,
characterized in that the outer diffuser (6) in its peripheral wall in the region of the outflow opening (8) has recesses (41) for receiving grid wires (38) of the protective grid (36) and the wall surfaces (31) of the Innenendiffusors (26) at their free Ends in the edge region have recesses (44) for receiving the grid wires (38). Housing according to claim 12,
characterized in that the inner diffuser (26) has a cover (43) which rests on the protective grille (36) on its downstream side and is connected to the air duct (29) via fastening means such that the protective grille (36) is enclosed between the connection cover (33) and the air guide section (29). Housing according to one of claims 1 to 13,
characterized in that the wall ring (2), the AußenendifFusor (6) and the struts (14) via fastening means (18, 19, 21, 22, 23) can be fastened. Housing according to claim 14,
characterized in that the wall ring (2) and the outer diffuser (6) each radially directed circumferentially extending bearing surfaces (19, 21) which lie in the mounted state to each other and by in the direction of the longitudinal axis (XX) extending fastening means (22) with each other and are connected to the struts (14). Housing according to one of claims 1 to 14,
characterized in that the wall ring (2) projects with its inlet nozzle section (3) into the outer diffuser (6) through its inflow opening (7) such that an axial gap (47) extending in the direction of the central longitudinal axis (XX) arises in an overlap area , Housing according to claim 16,
characterized in that the struts (14) connect the outer diffuser (6) and the wall ring (2) by radial to the longitudinal axis (XX) extending fastening means with the motor housing (17). Housing according to claim 17,
characterized in that the outer diffuser (6) has a plurality of attachment regions (18) which are widening outwardly and at their free ends an angled portion (19), wherein the angle (β) of the bend (19) ≥ 90 ° + α is, with α = cone angle of the outer diffuser (6).

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