EP4090853A1

EP4090853A1 - Housing for a fan, and fan with a corresponding housing

Info

Publication number: EP4090853A1
Application number: EP20845387.8A
Authority: EP
Inventors: Frieder Loercher
Original assignee: Ziehl Abegg SE
Current assignee: Ziehl Abegg SE
Priority date: 2020-01-15
Filing date: 2020-12-04
Publication date: 2022-11-23
Anticipated expiration: 2040-12-04
Also published as: DE102020200447A1; WO2021143972A1; EP4090853B1; CN114981544A; CN114981544B; JP2023510185A; US11859640B2; US20230032483A1; BR112022013007A2

Abstract

A housing for a fan, preferably for an axial or diagonal fan, wherein the fan comprises an impeller wheel and at least one throughflow region, is characterized in that a plurality of individual, freestanding guide elements are provided immediately downstream of the impeller wheel or of the blades of the impeller wheel in an outer region of the housing and therefore in the throughflow region. A fan comprises a corresponding housing.

Description

HOUSING FOR A FAN AND FAN WITH A CORRESPONDING HOUSING

The invention relates to a housing for a fan, preferably for an axial or diagonal fan, the fan comprising an impeller and at least one through-flow area. The invention also relates to a fan with such a housing.

Fans which comprise a drive, an impeller and a housing, in particular axial or diagonal fans, are well known from practice. It is also known to provide such fans with guide wheels, diffusers, multi-diffusers and combinations thereof in order to influence the flow. In particular, high static efficiencies are to be achieved.

Although the invention relates very generally to a housing for a ventilator and a ventilator with such a housing, this relates in particular to a ventilator and a housing provided there, as shown in terms of the basic structure in FIG. 1. For example, there is a fan 1 of axial design with a housing 2. A Leitein direction 15 can be made in one piece with the housing 2 in plastic injection molding. By way of example, it essentially comprises a hub ring 4, an outer ring 5, inner guide vanes 3 extending between them, and outer guide vanes 3 a, which extend between the outer ring 5 and the housing 2. In the assembled state of the fan, this guide device 15 is arranged downstream of an impeller (not shown there) within the housing 2, so that an air duct 6 is formed as an outer flow area between the guide device 15 or its outer ring 5 and the wall of the housing 2. Part of the air flowing off the impeller is passed through this outer flow area or air duct. Another part of the air flowing out of the impeller is passed through an inner flow area 7, which, as seen in the span direction, is delimited by the hub ring 4 towards the axis. Viewed towards the outer flow area 6, the inner flow area 7 is from the outer Ring 5 limited. The inner flow area 7 is equipped with inner guide vanes 3, which stabilize the swirling flow which is close to the axis and which emerges from the impeller by reducing the swirl in the flow. This increases the efficiency. The hub ring 4 and the outer ring 5 run essentially over the entire circumference around the axis. The hub ring 4 surrounds an inner receiving area 8 in which, for example, the drive motor of the fan is arranged. The receiving area 8 does not flow through it, or at most only a small volume flow of air flows through it in order to be able to remove the waste heat from the engine. The outer flow area 6 has a small number of outer guide vanes 3 a, which in particular assume the static connection of the outer ring 5 to the housing 2. Due to the small number of outer guide vanes 3a in the outer flow area 7, little additional noise is caused in this area as a result of the interaction of the flow emerging from the impeller with the outer guide vanes 3a. In the area of the radial gap between the impeller and the housing 2 and downstream therefrom, a strongly swirling flow occurs, whereby flow detachments occur on the inner wall of the housing in the area of the impeller and downstream thereof. A backflow through the radial gap between the impeller and the housing reduces the static efficiency in particular and ensures a not inconsiderable level of noise. The inner guide vanes 3 and the outer guide vanes 3a are advantageously load-bearing guide vanes, that is, they have, inter alia, the function of ensuring the load-bearing connection of the motor to the housing.

The present invention is based on the object of designing and developing the housing for such a fan, in particular for an axial or diagonal fan, in such a way that harmful influences of a so-called head gap leakage flow are at least reduced, if not largely eliminated. The effectiveness of downstream diffusers is to be improved, and blocking effects in the form of a backflow area are to be reduced. The problems occurring in the prior art are to be eliminated with simple structural means that distinguish both the housing according to the invention and the fan according to the invention from competitive products under. According to the invention, the object relating to the housing is achieved by the features of claim 1. According to this, the generic housing is characterized in that several individual, free-standing guide elements are provided immediately downstream of the impeller or the blades of the impeller in an outer region of the housing. The problem relating to the fan is achieved by the features of claim 18.

The features according to the invention appear amazingly simple, according to which individual obstacles are provided downstream of the impeller and thus downstream of the blades of the impeller where head gap leakage flows or a backflow area can occur, specifically in an outer area of the housing, regardless of which specific ones structural / constructive features have the housing and the fan. The obstacles are designed as individual free-standing guide elements, so they do not belong to a single or load-bearing guide device. They are available as individual structural elements that are advantageously formed directly on or in the inner wall of the housing.

In concrete terms, it is conceivable that the individual free-standing guide elements are formed by a combination of depressions and elevations in the inner wall of the housing in order to achieve special flow effects. This measure enables the inside wall of the housing to be properly profiled with the aid of free-standing guide elements.

In principle, it is conceivable that the individual free-standing guide elements, each seen individually, are integrated into the inner wall of the housing. The housing can be manufactured using injection molding or metal casting with integral individual free-standing guide elements.

Alternatively, it is conceivable that the individual free-standing guide elements, regardless of the material and the manufacture of the housing, are made of metal or plastic and are attached to the inner wall of the housing, for example by adhesive or welding technology. In order to achieve a sufficiently good fluidic effect, a sufficiently large number of free-standing guide elements is provided, depending on the size of the housing in the range between 20 and 100 pieces.

The individual free-standing guide elements can be arranged on the housing inner wall equidistant from one another over the circumference of the housing inner wall. An even distribution of the free-standing guide elements should bring about an effective stabilization of the otherwise swirling flow and / or rather deflect this flow in the flow direction. This means that turbulence can also be transported away from the impeller more quickly.

It is also conceivable that the individual free-standing guide elements with load-bearing guide vanes of a guide device alternate in their position seen in the circumferential direction, such that between two load-bearing guide vanes of the guide device, several individual free-standing guide elements, for example four to twelve free-standing guide elements, from the housing wall essentially protrude radially, possibly obliquely at a predetermined angle. In any case, it is essential that the individual free-standing guide elements are attached essentially immediately downstream of the impeller and there counteract a backflow counter to the actual conveying direction.

The individual free-standing guide elements can be designed identically and protrude from the housing inner wall at an identical angle. It is also conceivable that the individual free-standing guide elements are aligned alternately with alternating angles and correspondingly protrude from the inner wall of the housing in different directions.

Assuming a special housing which has a substantially circular cross-section with a substantially cylindrical, possibly ring-like flow area in which the impeller is arranged, it is advantageous if the individual free-standing guide elements at the end of the cylindrical area or are formed at the beginning of an adjoining, preferably widening diffuser area or in the transition between the two areas. The immediate proximity to the impeller is essential. That's how they work Free-standing guide elements counteract any flow separation on the inner wall of the housing downstream of the impeller, which results in a low-noise fan with high efficiency, namely as a result of flow stabilization by the individual free-standing guide elements on the inner wall of the housing. In addition, the provision of the individual free-standing guide elements improves the effectiveness of a diffuser integrated in the housing, which can be connected to the aforementioned cylindrical area of the housing wall.

In concrete terms, it is advantageous if the individual free-standing Leit elements extend only slightly less or slightly more than an annular gap formed between the blades of the impeller and the inner wall of the housing radially away from the inner wall of the housing. The ratio of the height of the individual free-standing guide element to the annular gap width can be in the range from 0.8 to 3.0. The axial distance between the individual free-standing guide element and the blade of the impeller is advantageously less than eight times the gap width on the housing wall.

The mere provision of the individual free-standing guide elements makes an enormous contribution to stabilizing the otherwise swirled flow in the area downstream of the radial gap between the impeller and the housing. Further optimization is possible through the specific shape of the individual free-standing guide elements. The individual free-standing guide elements can have a more rounded leading edge and a rather thin, “pointed” trailing edge.

In principle, it is advantageous if the individual free-standing guide elements have a profiled contour which roughly corresponds to the contour of a wing or an impeller blade. Such a measure also favors the effect and thus stabilization of the flow.

Furthermore, it is advantageous if adjacent individual free-standing guide elements have a certain inclination, ie below a certain angle Angle are aligned transversely to the longitudinal axis. In this case, it is again advantageous if free-standing guide elements that are adjacent in the circumferential direction, viewed in projection onto a plane perpendicular to the fan axis, do not overlap in the circumferential direction, or at least have a small distance from one another. This makes it easier to remove the mold from a casting tool, for example an injection molding tool.

At the free end, the individual free-standing guide elements can be designed differently, depending on the specific installation situation and dimensions. Thus, the individual free-standing guide elements can have a blunt, angular, rounded, beveled or even angled free end, which has a significant influence on the air flow. Coordination with the overall structural situation is an advantage.

Furthermore, the underlying object with regard to the claimed fan, in particular axial or diagonal fan, is achieved by using a housing with features according to one of claims 1 to 17. There is no need to make any further comments with reference to the versions relating to the housing.

There are now various possibilities for designing and developing the teaching of the present invention in an advantageous manner. For this purpose, reference is made on the one hand to the claims subordinate to claim 1 and on the other hand to the following explanation of preferred embodiments of a housing according to the invention and a fan according to the invention with reference to the drawing. In connection with the explanation of the preferred exemplary embodiments of the invention with reference to the drawing, preferred embodiments and developments of the teaching are also generally explained. Show in the drawing

Fig. 1, seen in a perspective view from the downstream side, a

Axial fan with a housing according to the invention with individual free-standing guide elements, FIG. 2 shows the fan with the housing of the fan from FIG. 1 in a side view and in section on a plane through the axis,

3 shows the housing of the fan from FIGS. 1 and 2 in a side view and in section on a plane through the axis,

4 shows a perspective view of a further embodiment of a fan with a housing according to the invention, seen from the downstream side,

FIG. 5 shows the fan and the housing according to FIG. 4 in a side view and in section on a plane through the axis,

6 shows a detailed view from FIG. 5, the area of the free-standing

Guide elements are shown enlarged and provided with additional reference numerals,

7 is a perspective view of a further embodiment of a housing according to the invention, seen from the downstream side, which has no guide devices,

FIG. 8 shows the housing according to FIG. 7 in a side view and in section on a plane through the axis,

9 shows a detailed view from FIG. 8 in the area of the fan axis, with an area of the individual free-standing guide elements being shown enlarged and provided with additional designations,

Fig. 10 shows a further detailed view from Fig. 8 in the area of the section through the housing wall above, with a region of the individual free-standing guide elements shown enlarged and provided with additional Be drawings, 11 shows a further embodiment of a housing according to the invention in a detailed view analogous to that according to FIG. 10, the individual free-standing guide elements being provided with a first type of winglets,

12 shows a further embodiment of a housing according to the invention in a detailed view analogous to that according to FIG. 10, the individual free-standing guide elements being provided with a second type of winglets,

13 shows a further embodiment of a housing according to the invention in a detailed view analogous to that according to FIG. 10, the individual free-standing guide elements being provided with a third type of winglets.

Fig. 1 shows a perspective view of a fan 1 according to the invention of axial design with a housing 2. A guide device 15 is advantageously made in one piece with the housing 2 in plastic injection molding, and in the exemplary embodiment consists essentially of a hub ring 4, an outer ring 5 in between extending inner guide vanes 3 and outer guide vanes 3a, which extend between the outer ring 5 and the housing 2. In the assembled state of the fan according to the invention, this guide device 15 is arranged downstream of a (not visible) impeller inside the housing 2, so that an air duct (outer flow area) 6 is created between the guide device 15 or its outer ring 5 and the wall of the housing 2 through which part of the air flowing off the impeller is passed. Another part of the air flowing out of the impeller is passed through the inner flow area 7, which, seen in the spanwise direction, is limited to the axis of the hub ring 4, and which, seen in the spanwise direction, is limited to the outer flow area 6 from the outer ring 5 . The inner flow area 7 is interspersed with inner guide vanes 3 (17 pieces in the exemplary embodiment, advantageously 9-23 pieces), which stabilize the swirling flow that is close to the axis and exiting the impeller by reducing the swirl in the Reduce flow. This increases the efficiency. The hub ring 4 and the outer ring 5 run essentially over the entire circumference around the axis. The hub ring 4 surrounds an inner receiving area 8 in which, for example, the drive motor of the fan can be arranged. There is no flow through the receiving area 8 or there is advantageously a low air volume flow (0.1% -2% of the total air volume flow) in order to be able to remove the waste heat produced by the engine. The flow through the receiving area 8 can also take place against the main conveying direction, in particular if it is driven by a pressure difference between the outflow and inflow side.

The outer flow area 6 has a smaller number (three to eight) of outer guide vanes 3 a, which in particular assume the static connection of the outer ring 5 to the housing 2. As a result of the small number of outer guide vanes 3a, little additional noise is caused in this area as a result of the interaction of the flow emerging from the impeller and the outer guide vanes 3a. A large number of free-standing guide elements 16 are attached to the inner wall of the housing 2, 54 pieces in the exemplary embodiment, advantageously 30-100 pieces. They are advantageously integrally connected to the housing 2, for example in plastic injection molding. Metal casting is also conceivable. It is also conceivable that free-standing guide elements made of plastic or metal are glued, welded or the like into a housing. The free-standing guide elements 16 are attached in an area on the housing wall on the inflow side of the guide device 15, but can also overlap with the latter when viewed in the axial direction. It is essential that the free-standing guide elements 16 are attached essentially directly, at a small distance, which is advantageously not greater than the axial extent of the relevant free-standing guide element 16, downstream of the impeller (not shown here). They have a free end facing away from the wall of the housing 2 and protrude from the wall of the housing 2 at only a relatively small height. The free-standing guide elements 16 ensure a stabilization of the, depending on the operating point, strongly swirled flow in the area downstream of the radial gap between the impeller and the housing 2 (see in particular also Fig. 6) and thus help to break off flow and / or turbulence on the inner wall of the housing in the area of Avoid impeller and downstream of it, at least reduce it, or transport it away in an accelerated manner in the flow direction.

Overall, a fan is obtained that is quiet and highly efficient, namely as a result of the flow stabilization or the flow acceleration in the flow direction through the free-standing guide elements 16 on the wall of the housing 2, which in particular improve the effectiveness of the outer diffuser 10 integrated in the housing 2 can.

FIG. 2 shows in a side view and in section on a plane through the axis the fan 1 with the housing 2 according to the invention from FIG. 1. The impeller 19, the motor 34 and the guide device 15 of the fan can be clearly seen. In the section through the guide device 15, the outer flow area 6 with the outer guide vanes 3a, the inner flow area 7 with the inner guide vanes 3 and a receiving area 8 within the hub ring 4 can be seen. The impeller 19 is arranged upstream of the guide device 15. When the fan 1 is in operation, the air flows roughly from left to right in this view, first through the inlet nozzle 9 integrated on the housing 2, then through the impeller 19, before it is divided into the outer flow area 6 and the inner flow area 7, in which the flow is stabilized by outer guide vanes 3a or inner guide vanes 3 (especially in the inner flow area 7) and in which kinetic energy of the flow is converted into pressure energy. In the exemplary embodiment, both the inner guide vanes 3 and the outer guide vanes 3a, in a section on a cylinder jacket coaxial to the fan axis, on their inflow-side edge facing the impeller 19, have an inflow edge angle that optimally matches the flow angle of the impeller 19 exiting and flow impinging on the outer guide vanes 3a and the inner guide vanes 3 is adapted. The inflow edge angle measured in relation to a plane through the axis is advantageously in a range between 20 ° and 70 °. The inner guide vanes 3 and / or the outer guide vanes 3a advantageously have a rounded inflow edge, and further advantageously a variable thickness with a profile similar to that of a wing or a drop. In a front area of the guide device 15 in the flow direction or in front of the guide device 15, the free-standing guide elements 16 attached. They stabilize the flow flowing off the impeller 19, which is strongly swirled in the area of the outer wall of the housing 2, and / or accelerate it in the flow direction and prevent or reduce detachments or turbulence. This prevents, or at least reduces, blocking effects of the outer flow area 6 caused by large detachment areas, which are harmful to the efficiency and the air performance.

There is a provision 18 for fastening a motor 34 in the area of the receiving area 8 within the hub ring 4. The motor 34, shown here schematically, is fastened there. The guide device 15 takes over the connection of the motor 34 and, indirectly via this, also the impeller 19 to the housing 2. The motor 34 is connected to the guide device 15 on the stator side. On the rotor side, the motor 34 is connected to the impeller 19 at a fastening device 30. The impeller 19 consists essentially of a hub ring 21 and blades 22 attached to it. The hub ring 21 is advantageously designed so that the stagger angle of the blades 22 can be adjusted depending on the needs of the ventilation application in which the fan 1 is used.

There are basically two different support concepts for the motor 34 with the impeller 19. On the one hand, as in the exemplary embodiment shown, a supporting guide device 15 can be provided. That is, a guide device 15 with an aerodynamic function connects the motor 34 to the housing 2 and holds it. On the other hand, the motor 34 can be attached to the housing 2 with a purely mechanical connection, for example consisting of rods, wire, flat material or the like. In such a case, a guide device 15 may or may not be provided.

In other exemplary embodiments, a guide device 15 can also be designed without an outer ring 5 and / or with only one type of guide vanes, which are advantageously load-bearing.

In Fig. 2 it can be seen that load-bearing guide vanes (here outer guide vanes 3a) viewed in the flow direction in the same area as the free-standing guide elements 16 are arranged. As a result, the free-standing guide elements 16 are in the Embodiment not evenly distributed over the circumference, but interrupted again and again by the outer guide wings 3a. In the exemplary embodiment, nine, advantageously four to twelve, free-standing guide elements 16 are arranged between two adjacent outer guide vanes 3a in the circumferential direction. In other embodiments, the free-standing guide elements 16 can also be arranged distributed uniformly or otherwise unevenly over the circumference.

3 shows the housing 2 of the fan 1 from FIGS. 1 and 2 in a side view and in section on a plane through the axis. The outer throughflow area 6 with the outer guide vanes 3a and the inner throughflow area 7 are well included the inner guide vanes 3, separated by the outer ring 5, can be seen.

In the exemplary embodiment, both the wall of the housing 2 and the hub ring 4 have a conical design towards the outflow end. An outer diffuser 10 is thus integrated in the housing 2. Both the inner through-flow area 7 and the outer through-flow area 6 are designed as diffusers towards their outflow end with a widening flow cross-section. This is, in particular with axial fans, very advantageous for the static degree of effectiveness. The outer ring 5 of the guide device 15 is also designed in the exemplary embodiment slightly conical, slightly expanding radially in the direction of flow.

The inner flow-guiding wall of the housing 2 essentially has the contour of an inlet nozzle 9, which is followed by a cylindrical area 11, followed by the radially opening diffuser area 10. The impeller advantageously runs at least for the most part in the area 29 in the flow direction at the level of the cylindrical flow area 11. The free-standing guide elements 16 can be arranged at the end of the cylindrical area 11 or at the beginning of the diffuser area 10 or in the transition area between the two areas. In any case, the free-standing guide elements 16 are attached downstream of the impeller 19 or its blades 22 (see FIG. 2). For the demolding of the housing 2 from a casting tool, in particular a plastic injection molding tool, there are advantages if the free-standing guide elements 16 are completely or widely are arranged going in the cylindrical area 11. For the axial compactness of the fan, however, it can be advantageous if the free-standing guide elements 16 are arranged at least to a large extent in the diffuser area 10, since the diffuser area 16 can then connect directly to the impeller 19.

Fastening provisions, for example fastening flanges, can advantageously be integrated or attached to a housing 2 and / or a guide device 15 on both the inflow and outflow side, which serve to fasten the fan to a higher-level system, for example an air conditioning system.

4 shows, in a perspective view from the downstream side, a further embodiment of a fan 1 with a housing according to the invention. In this exemplary embodiment, no guide device is provided downstream of the impeller 19 with the blades 22. A support device (not shown here), for example made of rod or flat material, must establish the connection between the motor 34 and the housing 2 in order to fix the motor 34 relative to the housing 2. The free-standing guide elements 16 run evenly distributed over the circumference directly downstream of the impeller 22 or the outer ends of its blades 22 on the inner, flow-guiding wall of the housing 2. The housing 2 has an outflow-side edge 25 at the downstream end of the outer diffuser 10, from which the air flows out of the fan 1 during operation. The blades 22 are advantageously provided at their outer end with so-called winglets 20, ie special geometric structures which positively influence the flow in the outer area of the blades 22 near the housing with regard to the noise emission of the fan 1 and / or with regard to its efficiency.

FIG. 5 shows in a side view and in section on a plane through the axis the fan 1 with the housing 2 according to FIG. 4. It can be seen that the free-standing guide elements 16 are in the flow direction, in the illustration essentially from left to right, directly to the impeller 19 or its blades 22, which are attached to the hub 21, connect. FIG. 6 shows a detailed view of FIG. 5, the area of the free-standing guide elements 16 on the wall of the housing 2 being shown enlarged and provided with additional designations. A wing 22 of the impeller 19 can be seen with its winglet 20 at the radially outer end. The blades 22 run in the area of the cylindrical area 11 at a distance from the housing 2, so that the impeller 19 does not streak during operation. As a result, a radial gap of width d 12 arises between the wing 22 and the wall of the housing 2, through which a return flow (leakage flow) of air is regularly created against the actual flow direction. As a result, a flow area with very high velocity components in the circumferential direction and low velocity components in the flow direction arises locally near the wall of the housing 2 in the area of the blades 22. This flow area induces high flow losses and sound missions, and can in particular lead to a blocking effect on a diffuser that is closing.

The free-standing guide elements 16, which run very close to the blades 22 downstream thereof, can significantly reduce these losses. These free-standing guide elements 16 convert some of the speed components in the circumferential direction into those in the axial direction, i.e. they rather deflect the local flow in the axial direction. This causes a reduction in the return flow area in the area of the radial gap with width d 12 and thus a reduction in the losses and the generation of sound as well as the (partial) blockage of an adjoining diffuser limited to the outside by an external diffuser 10.

The free-standing guide elements 16 run radially only very locally in the area of the radial gap of the impeller with the width d 12 or only a small factor beyond this. In practice, the free-standing guide elements 16 have the height h 23, measured from the wall of the housing 2. The ratio of h 23 to d 12 is advantageously in the range of 0.8-3. The axial distance between the free-standing guide elements 16 and the wing 22 on the wall of the housing 2 is advantageously less than 8 times the gap width d 12. In the exemplary embodiment, the free-standing guide elements 16 run in the region of the outer diffuser 10. In other embodiments, they can also run in the cylindrical region 11. If, as in the exemplary embodiment, they run in the area of the outer diffuser 10, the demolding of a one-piece housing 2 made of cast is made more difficult. Special demolding areas (not shown) are advantageously incorporated, which enable demolding with an open-close tool with demolding directions parallel to the axis without further slides.

In the context of the invention, the free-standing guide elements 16 cause the flow, which is subject to strong swirls, to be deflected in the area of the wall of the housing 2, rather in the axial direction. In other embodiments, other geometric solutions are also conceivable in which the free-standing guide elements are, for example, more strongly integrated into the contour of the housing, for example in the form of depressions, elevations or the like. It is essential that this flow influencing only takes place near the housing wall and in the immediate vicinity of the impeller blades, where there is an interaction with a leakage flow of a radial gap between the impeller blades and the housing.

7 shows a perspective view, seen from the outflow side, of a further embodiment of a housing 2 according to the invention, which does not have a guide device. The free-standing guide elements 16 run approximately evenly distributed over the circumference on the wall of the housing 2. The housing 2 has, on its flow-guiding inner wall, essentially an inlet nozzle 9, a cylindrical area 11 and an outer diffuser 10, which is located on the outflow-side edge 25 of the housing 2 ends.

Fig. 8 shows in a side view and in section on a plane through the axis 26, the housing 2 according to FIG. 7. The free-standing guide elements 16 are arranged approximately in the transition area between the cylindrical area 11 and the outer diffuser 10, that is, they run over the Boundary between the cylindrical area 11 and the outer diffuser 10, which is characterized in that, viewed in the flow direction, it gradually widens radially. The one-sided The opening angle of the contour of the outer diffuser 10 is approximately 12 ° in the exemplary embodiment, advantageously 6 ° -18 °.

FIG. 9 shows a detailed view from FIG. 8 in the area of the fan axis, an area of the free-standing guide elements 16 being shown enlarged and provided with additional reference symbols. As a result of the high magnification and the view of an area close to the axis (in the projection shown), an approximately flat section of the wall of the housing 2 is viewed.

The free-standing guide elements 16 have an inflow edge 13, which is advantageously at least approximately rounded, and an outflow edge 14 which is thin compared to the rest of the course. Advantageously, the free-standing guide elements 16, seen in cross section, have approximately the profiled contour of a wing. In other embodiments, other cross-sectional contours are also possible, for example a thin contour with an essentially constant thickness. The free-standing guide elements 16 have a chord length s 31 and an axial extension I 32. In terms of amount, I 32 is advantageously small, for example 0.2% -5% of the impeller diameter or 10% -60% of the axial extent of an impeller blade. The chord length s 31 is advantageously about a factor of 1.2-2 greater than I 32. When viewed in the circumferential direction, adjacent free-standing guide elements 16 advantageously do not overlap in order to enable easier removal of the housing 2 from a casting tool. The inflow angle α 27 is assigned to the inflow edge 13. This is the local angle between the chord 37 or its tangential extension and a parallel to the axis 26. The outflow edge 14 is assigned the outflow angle ß 28. This is the local angle there between the Skeleton line 37 or its tangential extension and a parallel to the axis 26. The angle β 28 is smaller than the angle α 27, advantageously by at least 20 °. As a result, the swirling flow is more likely to be deflected in the axial direction. The free-standing guide elements 16 have a front end 24 here.

FIG. 10 shows a further detailed view from FIG. 8 in the area of the section through the wall of the housing 2 at the top, an area of the free-standing guide elements 16 shown enlarged and provided with additional reference numerals is. The free-standing guide elements 16 have a blunt free end 24. In the cross section shown, seen approximately along the height of the free-standing guide elements 16, the free-standing guide elements 16 have approximately the contour of a rectangle. However, a rounded transition area 17 to the wall of the housing 2 is advantageously formed.

FIG. 11 shows a further embodiment of a housing 2 according to the invention in a detailed view analogous to the embodiment according to FIG. 10, the free-standing guide elements 16 being provided with a first type of winglets 38a at their open end. At the free end of the free-standing guide elements 16, a contour with a thickness of 1 mm to 3 mm protrudes toward the concave side of the free-standing guide elements 16. In the cross section shown, seen approximately along the height of the free-standing guide elements 16, the free-standing guide elements 16 have an approximately L-shaped contour.

FIG. 12 shows a further embodiment of a housing 2 according to the invention in a detailed view analogous to the embodiment according to FIG. 10, the free-standing guide elements 16 being provided with a second type of winglets 38b at their open end. On the convexly curved side of the free-standing guide elements 16, a type of bevel is formed towards the free-standing edge, so that the free-standing guide elements 16 taper approximately to a point towards their open end. At the outer end, the free-standing guide elements 16 are nevertheless not completely pointed, but rather provided with a very thin, finely thick end.

FIG. 13 shows a further embodiment of a housing 2 according to the invention in a detailed view analogous to the embodiment according to FIG. 10, the free-standing guide elements 16 being provided with a third type of winglets 38c at their open end. On the concavely curved side of the free-standing guide elements 16, towards the free-standing edge, a type of rounding is formed, so that the free-standing guide elements 16 appear approximately with a quarter-circle rounding towards their open end. The edge to the convexly curved side of the free-standing guide elements 16 remains at least approximately pointed. With regard to further advantageous configurations of the fan according to the invention with the housing according to the invention, reference is made to the general part of the description and to the appended claims in order to avoid repetition.

Finally, it should be expressly pointed out that the above-described exemplary embodiments of the fan according to the invention together with the housing according to the invention are only used to explain the teaching claimed, but do not limit them to the exemplary embodiments.

List of reference symbols

1 fan

2 housings

3 inner guide vane a outer guide vane

4 hub ring, inner ring of the

Guidance device

5 outer ring of the guide device

6 outer flow area

7 inner flow area

8 Recording area within the

Hub ring

9 inlet nozzle 0 outer diffuser 1 cylindrical flow area of the housing 2 width d of the radial gap of the impeller 3 inflow edge of a free-standing guide element 4 outflow edge of a free-standing guide element

Guide element 5 guide device 6 free-standing guide element 7 transition area of a free-standing

Guide element to the housing 8 fastening arrangement for the motor

Guide device 9 impeller 0 winglet of a blade of the impeller 1 hub ring of the impeller 2 blades of the impeller 3 height h of a free-standing Guide element front end of a free-standing guide element outflow-side edge of the housing axis of the fan inflow-side angle a of a free-standing guide element outflow-side angle ß of a free-standing guide element area for an impeller fastening provision for motor on the impeller chord length s of a free-standing guide element axial extension of a free-standing skeleton motor

Guide element with tangential extension a, winglets of free-standing b, guide elements c

Claims

Expectations

1. Housing for a fan, preferably for an axial or diagonal fan, the fan comprising an impeller and at least one flow area, characterized in that immediately downstream of the impeller or the blades of the impeller in an outer region of the housing, several individual , free-standing guide elements are provided.

2. Housing according to claim 1, characterized in that the individual free-standing guide elements are formed out directly on or in the inner wall of the housing.

3. Housing according to claim 1 or 2, characterized in that the individual free-standing guide elements are formed by a combination of depressions and elevations in the inner wall of the housing.

4. Housing according to one of claims 1 to 3, characterized in that the individual free-standing guide elements are integrated into the inner wall of the housing.

5. Housing according to claim 4, characterized in that the housing is made in plastic injection molding or metal casting with integral individual free-standing Leit elements.

6. Housing according to one of claims 1 to 3, characterized in that the individual free-standing guide elements are made of metal or plastic and are glued to the inner wall of the housing.

7. Housing according to one of claims 1 to 6, characterized in that the number of individual free-standing guide elements is in the range between 20 and 100 pieces, preferably 30 to 90 pieces, in particular 40 to 70 pieces.

8. Housing according to one of claims 1 to 7, characterized in that the individual free-standing guide elements are arranged on the housing inner wall equidistant from one another over the circumference of the housing inner wall.

9. Housing according to one of claims 1 to 7, characterized in that the individual free-standing guide elements are arranged distributed unevenly over the circumference of the inner wall of the housing.

10. Housing according to claim 9, characterized in that the individual free-standing guide elements with supporting guide elements of a Leitein direction alternate in their position, such that between two supporting Leit wings of the guide device several individual free-standing guide elements, for example, 4 to 12 free-standing guide elements, protrude radially from the inner wall of the housing in wesent union.

11. Housing according to one of claims 1 to 10, characterized in that the individual free-standing guide elements are designed identically and protrude at an identical angle from the housing inner wall.

12. Housing according to one of claims 1 to 11, wherein the housing has a substantially circular cross-section with a substantially cylindrical flow area in which the impeller is arranged, characterized in that the individual free-standing guide elements at the end of the cylindrical area or at the beginning an adjoining, preferably widening diffuser area or are formed in the transition between the areas.

13. Housing according to one of claims 1 to 12, characterized in that the individual free-standing guide elements extend radially away from the housing inner wall by slightly less or slightly more than the width of an annular gap formed between the blades of the impeller and the inner wall of the housing, the ratio the height of the individual free-standing guide element to the width of the annular gap can be in the range from 0.8 to 3.0 and wherein the axial distance of the individual free-standing guide element to the wing of the impeller on the inner wall of the housing can be less than 8 times the ring gap width.

14. Housing according to one of claims 1 to 13, characterized in that the individual free-standing guide elements have a more rounded leading edge and a rather thin trailing edge.

15. Housing according to one of claims 1 to 14, characterized in that the individual free-standing guide elements in section on a cylinder jacket coaxial to the fan axis have a profiled contour, approximately that of a support wing or an impeller blade.

16. Housing according to one of claims 1 to 15, characterized in that adjacent individual free-standing guide elements, based on a certain inclination, viewed in a projection onto a plane perpendicular to the fan axis, do not overlap or at least have a slight distance from one another.

17. Housing according to one of claims 1 to 16, characterized in that the individual free-standing guide elements have a blunt, angular, rounded, beveled, or angled free end.

18. Fan, in particular axial or diagonal fan, characterized by a housing with features according to one of claims 1 to 17.