EP2282135B1 - Ventilator - Google Patents

Description

The invention relates to a fan with at least one impeller having an axis of rotation and at least one suction duct with an air intake opening upstream of the impeller or with at least one blowing duct with an air outlet opening downstream of the impeller, to which - to form a lateral air inflow or outflow - a cover by a distance is arranged.

Fans of the type mentioned are known from the prior art. An exemplary fan according to the preamble of claim 1 is in the patent document DE-19925439-A described. They are often used in ventilation systems to supply or remove air from an environment. For example, exhaust air can be removed from the environment with the aid of the fan, or fresh air can be introduced into the environment. For this purpose, the fan has an impeller which is driven, for example, by an electric motor. An air flow through the fan is generated by means of this impeller. If the fan is in an exhaust air version, it has the at least one suction duct with an air intake opening located upstream of the impeller, the cover being arranged at a distance from the air intake opening to form the lateral air flow. Alternatively, the fan can also be available as a supply air version. In this case, a blowing duct is provided which essentially corresponds to the suction duct except for the direction of flow. The same applies to an air outlet opening, which takes the place of the air intake opening. In this case, the air flow mentioned is an air flow. For the supply air version, there is therefore a fan with at least one Blow duct with an air outlet opening located downstream of the impeller, to which the cover is arranged at a distance to form a lateral air outflow. The cover is not only intended to form the lateral air flow, but also forms an optical cover for the fan or the air intake or air outlet opening. However, the known fans have a strong pressure loss, which is dependent on an air volume flow that passes through the fan. This results on the one hand in high energy consumption or poor efficiency of the fan and on the other hand in unfavorable acoustic behavior. The efficiency refers to the ratio of the air output (i.e. the amount of air conveyed) to the energy supplied to the fan.

It is therefore an object of the invention to provide a fan which does not have the disadvantages mentioned at the outset, but which improves the air throughput, preferably over an entire characteristic curve range of the fan. At the same time, the acoustic behavior of the fan is to be improved.

This is achieved according to the invention with a fan with the features of claim 1. It is provided that at least one air guide means is arranged in a zone between the rear of the cover and the impeller, which reduces or prevents an air flow around the axis of rotation. An air vortex corresponding to the direction of rotation of the impeller is induced in the suction or blowing duct by the impeller rotating during operation of the fan. The air guide means has a defined axial extent. It is therefore not just for supporting one other element - for example a filter - but rather suitable for guiding the air flow flowing through the fan. By guiding the air, the air flow around the axis of rotation is reduced or prevented, that is to say, in the region of the air guide means or downstream thereof, the occurrence of the air vortex induced by the impeller is at least partially prevented. As described above, the air flow around the axis of rotation is reduced or prevented not only in the region of the air guide means, but also around an imaginary extension of the axis of rotation. Depending on whether the exhaust air version or the supply air version of the fan is present, it can be located upstream or downstream of the air guide.

The arrangement of the air guide in the zone between the back of the cover and the impeller makes it possible to significantly improve the air performance of the fan and, in particular, to reduce or eliminate strictly unstable areas in the characteristic curve (pressure increase Δp over the volume flow). The characteristic curve of a fan is usually described by three areas. A stable area (also called a work area), a strictly unstable area and a simply unstable area. The strictly unstable range lies between the simply unstable (low volume flow) and the stable range (high volume flow). For example, in an axial air conveying device, the strictly unstable area of the characteristic curve is determined by a more or less pronounced (mathematical) saddle point. This should generally be reduced to a minimum. By arranging the cover in front of the air intake opening, the strictly unstable area initially increases. With help However, the air guide can be reduced or even completely eliminated.

This also significantly improves the acoustic behavior of the fan, so that it can be operated with less noise than known products. The arrangement of the air guide means on the fan, in particular when the fan is throttled, can practically double the static overpressure in the fan. At the same time, a filter can be arranged on the air guiding means or can be supported on it. In this context it should be emphasized again that the air guiding means has an air guiding function and is not only used to arrange the filter in this area. Air vortices between the air guiding means and the cover should be reduced or prevented.

The cover is assigned to the fan, but does not have to be attached directly to it. It can be provided, for example, to install the fan in a wall and to fix the cover not to the fan itself or to a housing of the fan, but to the wall. The cover is preferably a closed cover, so it is impermeable to air. The air flowing through the fan can therefore only pass the cover laterally from the cover.

Further advantageous embodiments result from the subclaims.

The invention provides that the air guide means has at least one air guide web and a flow guide means arranged on the back of the cover. The air duct is designed in such a way that it opposes the lowest possible flow resistance to the air flow present in the fan, but at the same time exerts a guiding effect on the air flow. For this purpose, it has the smallest possible cross section perpendicular to a flow direction of the air flow, while it has a pronounced extension in the axial direction or air flow direction. The air guide web can penetrate the entire air guide means or can be formed only in one area. In the latter case, a plurality of air guide webs are preferably provided, which for example run parallel to one another. Alternatively or additionally, the flow guide means is provided on the back of the cover or is formed there.

A further development of the invention provides that the air guide means provides at least one holding web that supports the air guide web. The holding web can be present downstream, upstream or - based on the flow - at the same axial position. The holding web serves in particular to stiffen the air guiding means by supporting the air guiding web. This can prevent the air guide from being excited by the flow to vibrate, which would have a negative effect on the acoustic properties of the fan. The holding web can be connected to the air guide web, in particular attached to it. A one-piece design of the retaining bridge and air guide bridge is also possible. The holding web can have the same or at least a similar axial extent as the air guide web. The holding web can, for example, run at an angle to the air guide web. For example, a 90 ° angle is provided, so the holding web is perpendicular to the Air duct. Like the air guide bar, the holding bar can serve to guide the air flow.

A further development of the invention provides that the air guide bar and / or holding bar are held in a frame. The frame can, for example, be exchangeably fastened in the zone. In this case, a latching device can be provided in order to be able to remove the air guide means or the frame of the air guide means from the fan in a simple manner or to replace the air guide means. Preferably, a positive connection with a housing of the fan is provided on at least one side of the frame, while the latching element is arranged on the opposite side. In this way, the frame can be folded out of the housing of the fan and then removed after the latching means has been opened.

A further development of the invention provides that the air guide web and / or the holding web runs straight, obliquely, arched, star-shaped or meandering at least in some areas. In principle, the course of the air guide web or the holding web can be chosen arbitrarily. In particular, the air guide web or holding web can be designed continuously in the above-mentioned ways. However, provision can also be made for the air guide web or holding web to run straight in some areas and, for example, to be curved in at least one further area. Arc-shaped means that there is a curvature or a curve. A straight course can mean that the air guide web or holding web runs parallel to at least areas of the frame, should one be provided. Alternatively, the oblique or star-shaped Realizable. In the course of the course, the course of a cross section of the air guide web or the holding web is considered. The profiles described can also exist if the respective web is inclined in the axial direction or is profiled.

A further development of the invention provides that the air guide web and / or the holding web are profiled. This means that they have a flow guide profile, at least in some areas - as seen in cross section. The flow characteristic of the air flow can be influenced in a more targeted manner by means of the flow guide profile than would be possible with an unprofiled version. A flow guide profile can be understood to mean, for example, an airfoil profile, that is to say specially shaped flow profiles which specifically influence the air flow.

A further development of the invention provides that the air guide web and / or the holding web open into a support element. In order to increase the stability or rigidity of the air guide means, the support element can be provided. The support element is provided, for example, centrally on the air guide means, so that the air guide web or the holding web open into it at least on one side. In principle, the support element can be of any shape. For example, it can have a rectangular cross section.

A further development of the invention provides that the flow guide means has at least one flow guide web and / or a flow guide structure formed at least in regions on the back of the cover. The flow guide here denotes an element which has at least one free surface, which points in particular away from the back of the cover. The flow guide web has the greatest extent in its longitudinal direction, while the height of the flow guide web is less than or equal to the distance between the rear of the cover and a housing of the fan. However, the flow guide webs advantageously have a smaller height than this distance. The flow guide webs form flow guide channels on the back of the cover. The air flow passing through the fan is guided in these flow channels. In this way, a targeted alignment of the air flow can be achieved. In particular, such an arrangement achieves a reduction in induced air vortices and thus a reduction in the air flow around the axis of rotation. In addition, the back of the cover can have elements which effect an additional guidance of the flow. The flow guide structure is provided for targeted guidance of the flow or for the formation of an advantageous turbulence structure of the flow. The latter means in particular that a flow resistance which is applied to the air flow from the rear is reduced.

A further development of the invention provides that the flow guide web is a flow guide rib or a row of pins. The flow guide rib is essentially characterized in that, unlike the row of pins, it is not composed of many individual elements, i.e. pins. Rather, an essentially continuous course of the flow guide rib is provided. However, this does not mean that the flow guide rib must run continuously. The row of pens, on the other hand, is composed of many individual, essentially peg-shaped elements that are directly next to each other or are placed at a distance from one another and thus form the flow guide web in its entirety. A combination of flow guide rib and row of pins is also possible. In this case, a flow guide rib is provided and overlaid by the row of pins, so that, for example, the wall thickness of the flow guide rib thicken at intervals in the flow guide rib.

A further development of the invention provides that the flow guide web has a constant or a, in particular continuously, increasing height. Depending on the direction or definition of the variable height, there can of course also be a decreasing height. If the flow guide web is arranged, for example, in the radial direction, the height of the flow guide web can be provided to increase radially inwards. Continuous growth is advantageous. Of course, a sudden increase in altitude or an increase based on a curve shape is also possible.

A further development of the invention provides that the flow guide web has a straight or a curved course. Such a course only has to exist in certain areas. The flow guide bar does not have to run straight or curved throughout. The curved course can be provided, for example, in order to impart a swirl to the air flow which is opposite to the swirl of the air flow around the axis of rotation which is induced by the impeller. With a suitable coordination of the curvature, a complete compensation of the swirl can then be achieved, at least for predetermined mass flows, and thus the air flow around the axis of rotation can be prevented will. However, this goal can also be achieved by means of the straight course of the flow guide bar, the geometry of the flow guide bar also having to be adapted to the air flow induced by the impeller around the axis of rotation in this case too.

A further development of the invention provides that the flow guide rib runs continuously or is interrupted in some areas. In the former case, the flow guide rib runs continuously. In the latter, it is divided into areas which can each have the same or a different length. For example, it can also be advantageous to choose the length of the areas depending on a position of the area. For example, in the case of a radially outwardly extending flow guide rib, areas with a shorter length can be provided in an inner area and with a longer length in an outer area. The increase in length can take place continuously. The distance between the areas can accordingly remain constant or also have a growing or falling length.

A further development of the invention provides that the flow guide web has at least one air passage. Air passage is generally to be understood as a recess. This can be a hole, but also only a bulge or notch of the flow guide. Such a design of the flow guide web is advantageous in terms of sound technology. A surface can be provided with a structure by means of the air passage. This means that the height of the flow guide bar is varied locally by means of the air passages.

A further development of the invention provides that the flow guide web is profiled at least in some areas. It therefore has a flow guide profile at least in some areas. The term “flow guide profile” or “profiled” has already been defined above on the basis of the air guide web or the holding web.

A further development of the invention provides that the flow guide structure has dimples, riblets and / or winglets. A golf ball-like structure is created using the dimples. There are bulges and / or bulges on the back of the cover. The riblets form a groove and / or scale structure. The winglets are primarily used to induce further vortex structures that either reduce flow resistance or counteract the air flow induced by the impeller around the axis of rotation. The dimples and the riblets can be used to reduce the frictional resistance on the back of the cover. The riblets can for example be designed such that a free end pointing away from the rear tapers.

A further development of the invention provides a plurality of flow guide webs which are staggered with respect to one another at least at one of their ends. This means that the end of a flow guide web is advanced or falls back compared to the end of another flow guide web. For example, a staggering in the radial direction can be provided in the case of a radial arrangement of the flow guide webs. In this way, it is prevented that the flow-through cross section is blocked by the flow guide webs, which is particularly the case when all the radial flow guide webs extend into a center of the rear of the cover to run. Nevertheless, such an arrangement can be advantageous and can be implemented in an embodiment of the fan.

A further development of the invention provides that at least one free space, in particular a circular top view, is provided on the back of the cover, in which no flow guide web and / or no flow guide structure is provided. In order to deal more effectively with the problem just described, the free space is provided. In principle, this can have any geometry, for example it is circular. The flow guide webs can at least partially end outside the free space; additionally or alternatively, no flow guide structure is also provided in the free space. The free space can be arranged, for example, centrally on the back of the cover.

A further development of the invention provides that the cover - in plan view - is rectangular, in particular square, round or oval. In principle, the cover can have any shape. However, the shape of the cover is preferably matched to a shape of the housing of the fan. In this case, the cover — in plan view — can completely cover further areas of the fan, that is to say at least have the same size or be larger. Alternatively, however, a smaller cover can also be implemented.

A further development of the invention provides that the air guiding means is fastened, in particular interchangeably, to a housing of the fan. For example, the frame of the air guide means is provided for this purpose, on which the air guide web and / or holding web are arranged. It is particularly advantageous if the air guiding means is exchangeable.

For this purpose, it is designed to be removable from the housing of the fan. Alternatively, however, the air guiding means can also be fastened to the housing of the fan without a frame. For example, it is provided that the air guide web and / or the holding web are formed in one piece with the housing. A spacer can also be provided between the housing and the air guiding means, in particular in order to arrange the latter at a distance from the impeller and the rear of the cover.

A further development of the invention provides that the air guiding means and / or the cover are made in one piece. The air guiding means or the cover can be produced particularly simply and inexpensively if they are made from one piece, that is to say that no assembly process is necessary after manufacture. The one-piece design of air guiding means or the cover is therefore advantageously present immediately after their manufacture.

A further development of the invention provides that the air guiding means and / or the cover consist at least in regions of plastic and / or metal. For example, the air guiding means can consist of sheet metal, in particular the air guiding webs or holding webs can be formed from sheet metal strips. Of course, other suitable materials can also be used to produce the air guide and / or the cover.

A further development of the invention provides that the air guiding means and / or the cover are present as a molded part or as a shaped part. This means that they are manufactured by injection molding or by forming. The injection molding process can or be a multi-component process. Forming is carried out, for example, with a deep-drawing process. Alternatively, however, the air guiding means and / or the cover can also be composed of individual parts.

A further development of the invention provides that the impeller is part of an axial, radial or diagonal air conveying device. The air delivery device is a turbomachine which, in the sense of the fan, serves to generate the air flow through the fan. Due to its rotational movement, the impeller causes the air flow around the axis of rotation, which is to be reduced or prevented by the measures explained above. The diagonal air delivery device corresponds to a semi-radial air delivery device.

A further development of the invention provides that a stator is provided downstream or upstream of the impeller. In order to optimize the air delivery capacity of the impeller, the stator is provided, which is arranged in particular directly adjacent to the impeller. In the upstream arrangement, the air flow flows through the stator to the impeller, while in the downstream arrangement the air is first conveyed through the impeller and then flows through the stator.

A further development of the invention provides that use is provided in an outside area or an inside area. The fan described above is suitable for both indoor and outdoor use. Only the materials from which the fan or its components are made need to be matched to the place of use.

Figur 1

eine perspektivische Anordnung eines Ventilators mit einem Gehäuse und einer Abdeckung, wobei die Abdeckung an dem Gehäuse befestigbar ist,

Figur 2

eine Frontansicht sowie einen Querschnitt des Ventilators, wobei in dem Querschnitt ein Laufrad sowie ein Luftleitmittel zu erkennen sind,

Figur 3

eine schematische Darstellung des Ventilators, wobei das Gehäuse in einer Schnittdarstellung abgebildet und die Abdeckung in Bezug zu dem Gehäuse gekippt ist, sodass eine Unterseite der Abdeckung erkennbar ist,

Figur 4

das Gehäuse des Ventilators, wobei ein Gehäusedeckel entfernt wurde, sodass das Luftleitmittel erkennbar ist,

Figur 5

eine erste Ausführungsform des Luftleitmittels,

Figur 6

eine zweite Ausführungsform des Luftleitmittels,

Figur 7

eine dritte Ausführungsform des Luftleitmittels,

Figur 8

eine Draufsicht auf die Rückseite der Abdeckung, auf welcher ein einen Strömungsleitsteg aufweisendes Strömungsleitmittel angeordnet ist,

Figur 9

verschiedene Ausführungsformen des Strömungsleitstegs in Draufsicht,

Figur 10

verschiedene Ausführungsformen des Strömungsleitstegs in einer Querschnittsdarstellung, und

Figur 11

ein Diagramm, in welchem Kennlinien für einen herkömmlichen und einen erfindungsgemäßen Ventilator dargestellt sind.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing, without the invention being restricted. Show it:

Figure 1

1 shows a perspective arrangement of a fan with a housing and a cover, the cover being attachable to the housing,

Figure 2

2 shows a front view and a cross section of the fan, an impeller and an air guide being recognizable in the cross section,

Figure 3

2 shows a schematic illustration of the fan, the housing being shown in a sectional illustration and the cover being tilted in relation to the housing, so that an underside of the cover can be seen,

Figure 4

the housing of the fan, a housing cover having been removed so that the air guide can be seen,

Figure 5

a first embodiment of the air guide means,

Figure 6

a second embodiment of the air guide means,

Figure 7

a third embodiment of the air guide means,

Figure 8

3 shows a plan view of the rear of the cover, on which a flow guide means having a flow guide web is arranged,

Figure 9

different embodiments of the flow guide in top view,

Figure 10

different embodiments of the flow guide in a cross-sectional view, and

Figure 11

a diagram in which characteristics for a conventional and a fan according to the invention are shown.

The Figure 1 shows a fan 1 with a housing 2, to which a cover 3 can be attached. In plan view, the cover 3 is essentially rectangular, in particular square, and is adapted to the shape of the housing 2. It is provided that the cover 3 projects beyond the housing 2 to the side. Alternatively, it can also be provided that the cover - in plan view - is as large or even smaller than the housing. The cover 3 is detachably attached to the housing 2. This can be provided, for example, by means of a plug-in device, so that the cover 3 can be easily attached to and removed from the housing 2, but no unintentional removal or falling off of the cover 3 from the housing 2 is possible. The housing 2 consists of a housing body 4 and a housing cover 5, the housing cover 5 being held detachably on the housing body 4 by means of latching means. In the present exhaust air version of the fan 1 there is an air intake opening 6 in the housing cover 5. Through this air is sucked into the interior of the fan 1. In the area of the air intake opening 6, an air guiding means 7 can be seen, which consists of a frame 8, a holding web 9 and several air guiding webs 10. A surface 11 of the housing cover 5 is - in cross section - convex, the shape of the cover 3 forming a corresponding counterpart, ie - in cross section - is also convex. This results in a spherically shaped recess in the housing cover 5 or the cover 3.

The Figure 2 shows a front view of the fan 1, the cover 3 being recognizable at first. In the Figure 2 a sectional view is also shown, in which a cross section (marked on the cover 3) of the fan 1 is shown. This cross-sectional illustration shows that an impeller 12 and a stator 13 are arranged in the fan 1 or in the housing 2, which are part of an air conveying device 14. This serves to suck in air from an environment 15 of the fan 1 and to convey it in the direction of an outlet 16. The air delivery device 14 is arranged in a suction channel 17 connected to the outlet 16 in terms of flow. In this case, the air intake opening 6 - the exhaust air version of the fan 1 - is provided downstream of the impeller 12. The cover 3 is in turn spaced apart from the air intake opening 6 or the housing 2 and thus from the housing cover 5. The air guiding means 7 is arranged in a zone 18, which is between a rear side 19 of the cover 3 and the impeller 12 of the air conveying device 14. The retaining web 9, which runs from top to bottom, or the air guide webs 10 and the frame 8 arranged perpendicularly thereto, can be seen in this context. The air guide means 7 has a certain extent in the axial direction (with respect to an axis of rotation 20). It is therefore suitable for guiding an air flow which is passed through the air delivery device 14 is generated. Due to the axial extension of the air guide 7, this serves to reduce or completely prevent an air flow around the axis of rotation 20.

In order to achieve an even better guidance of the air flow, a further air guide 7 'in the form of a flow guide 21 is provided on the back 19 of the cover 3. In addition, the rear side 19 is at least partially provided with a flow guide structure (not shown).

The Figure 3 shows a cross-sectional view of the housing 2 of the fan 1. In addition, the cover 3 is shown in an exploded view, the rear side 19 being recognizable. The Figure 3 also shows that the impeller 12 is driven by an electric motor 22. It can also be seen that an edge 23 of the air intake opening 6 formed in the housing cover 5 is curved in cross section in the direction of the air conveying device 14. In this way it is avoided that there are sharp-edged areas in the flow path, which could have a disadvantageous effect on the acoustics of the fan 1.

The flow guide means 21 formed on the rear side 19 of the cover 3 has a plurality of flow guide webs 24, each of which is present as a flow guide rib 25. A free space 26 with a circular cross section is provided centrally on the rear side 19. None of the flow guide ribs 25 is present in the area of the free space 26, and they therefore end outside the free space 26. In this case, their ends 27 are staggered with respect to one another. This means that the flow guide ribs 25, which are at an angle of a multiple are arranged at 45 °, directly adjoin the free space 26, while further flow guide ribs 25 are radially spaced from the free space 26. However, the angle specified here is to be understood purely as an example. Of course, other angles, not mentioned here, of the flow guide ribs 25 are also possible. It may also be useful for some applications not to provide a free space 26, but to guide the flow guide ribs 25 to the center of the cover 3.

The cover 3 is formed in one piece. The flow guide ribs 25 are therefore already present immediately after the cover 3 has been produced. For example, the cover 3 is manufactured as a molded part. Between the flow guide ribs 25 there are flow channels 28 through which the air flow entering the air intake opening 6 at least partially flows. The flow guide ribs 25 guide the air flow.

The flow guide ribs 25 are designed such that they have a comparatively large height in the region of the free space 26, which drops radially outwards. This drop occurs continuously, so that a linear change in the height of the flow guide ribs 25 or the flow guide webs 24 is provided. The flow guide ribs 25 run in a straight line from the free space 26 radially outwards.

The Figure 4 shows an isometric view of the fan 1, wherein the cover 3 and the housing cover 5 have been removed. The housing body 4 is thus shown, to which the air guide means 7 is removably attached with its frame 8. To this end 8 catch elements 30 are provided on one side of rear grip elements 29 and on the opposite side of the frame.

The Figure 5 shows a first embodiment of the air guide 7 in a plan view. It is clear that the air guide means 7 has the peripheral frame 8, in which both the holding web 9 and a plurality of air guide webs 10 are fastened. The air guide webs 10 are perpendicular to the holding web 9 and run essentially parallel to one another. Both the holding web 9 and the air guide webs 10 are just arranged in the frame 8. The air guide 7 is formed in one piece and is made, for example, as a molded part made of plastic. The holding web 9 is provided on the air-guiding means 7 in order to support the air-guiding webs 10 over their longitudinal extent and thus in particular to prevent them from being excited to vibrations which could have a negative effect on the acoustic behavior of the fan 1.

The Figure 6 shows a second embodiment of the air guide 7. The frame 8 and the retaining web 9 are also provided here, but there is only one air guide web 10 which extends in a meandering manner over a flow area 31 of the air guide 7. Loops of the meandering air guide web 10 can be at a constant distance or - as in the present exemplary embodiment - at a changing distance.

The Figure 7 shows a third embodiment of the air guide means 7. Two retaining webs 9 and a plurality of air guide webs 10 are arranged in the frame 8. A support element 32 is provided centrally in the air guide means 7. This has an essentially rectangular Cross section on. The holding webs 9 open into the support element 32 with one of their ends, while the other is held on the frame 8. The holding webs 9 are in the air-guiding means 7 in a star shape, while the air-guiding webs 10, viewed in cross section, enclose rectangles with different surfaces.

The Figure 8 shows the back 19 of the cover 3 in plan view. Recognizable here is again the free space 26, which is arranged centrally on the rear side 19 and has a circular cross section, and the flow guide ribs 25, which, starting from the free space 26, extend radially outward in a radial direction to an edge 33 of the cover 3. As already stated above, a surface 34 of the rear side 19 is provided with a flow guide structure (not shown).

The Figure 9 shows several embodiments for the flow guide web 24 in plan view. A curved course with a constant width is shown at the top, the flow guide web 24 being designed as a flow guide rib 25. This is followed by a flow guide web 24 or a flow guide rib 25, which runs straight, but has lateral recesses 35 with a substantially semicircular cross section, with which the cross section of the flow guide rib 25 varies over its length. The next embodiment of the flow guide web 24 is composed of a thin flow guide rib 25 and a row of pins 36 overlying it. The row of pins 36 consists of pins 37 arranged at regular intervals, the diameter of which is larger than the width of the flow guide rib 25. In this way, a variable cross section of the flow guide web 24 is also achieved. The fourth embodiment of the flow guide web 24 is a straight one Flow guide rib 25. This is followed by an embodiment of the flow guide web 24, a flow guide rib 25 not running continuously but being interrupted in some areas. The flow guide rib 25 is subdivided into regions 38 ', 38 ", 38'" and so on, the region 38 'having a short length and the subsequent elements (including the regions 38 "and 38'") each having a greater length than the previous range. The distances between the areas 38 ', 38 ", 38'" and so on remain constant over the entire length of the flow guide rib 25. The next embodiment of the flow guide web 24 is a row of pins 36 which, as already stated, consists of a plurality of pins 37. The row of pins 36 shown here consists of pins 37, each with a constant cross-section or diameter, which are each at the same distance from adjacent pins 37. The last embodiment of the flow guide web 24 forms a flow guide rib 25 which has a constant cross section and a curved course. Curved does not mean that the curvature only points in one direction; rather, all of the curves that are curved or curved at least in sections are summarized here under this term.

The Figure 10 shows several examples of flow guide webs 24 in a side view. It is clarified here that the flow guide webs 24 designed as flow guide ribs 25 can have both a constant (third, fourth and sixth embodiment) and an increasing or decreasing height (first, second and fifth embodiment). The flow guide ribs 25 of the first four embodiments have air passages 39 which essentially reduce the height of the air locally Flow guide rib 25 mean. Air can flow through the air passages 39, which significantly improves the acoustic behavior of the fan 1.

The Figure 11 shows a diagram for the pressure increase Δp over the volume flow. The diagram shows characteristic curves 40 and 41 for a conventional (characteristic curve 40) and a fan 1 provided according to the above explanations (characteristic curve 41). The characteristic curve 40 can be roughly divided into three areas, namely a simply unstable area 42, which is available for volume flows from 0 m ³ / h to about 15 m ³ / h, a strictly unstable area 43 (about 15 m ³ / h to about 40 m ³ / h) and a stable area 44 (greater than about 40 m ³ / h). A saddle point 45 is present in the strictly unstable area 43. The characteristic curves 40 and 41 run almost congruently in the stable region 44. In the strictly unstable area 43 and the simply unstable area 42, on the other hand, the pressure increase with the same volume flow for the characteristic curve 40 is significantly lower than for the characteristic curve 41. In particular, the strictly unstable area 43, which is clearly pronounced for the characteristic curve 40, is marked with a Fan 1, as described above, largely avoided. In particular at low volume flows, that is to say in the simply unstable area 42 and / or the strictly unstable area 43, a significantly greater pressure increase can be achieved with the fan 1.

Claims (14)

1. A ventilator (1) with at least one impeller (12) having an axis of rotation (20) and at least one suction channel (17) with an air suction opening (6) situated upstream of the impeller (12), wherein a cover (3) is arranged with a distance from the opening in order to establish a lateral air flow, the cover being attached to a housing (2) of the ventilator (1) that features the air suction opening (6), wherein at least one air conducting means (7, 7') that reduces or prevents an air flow around the axis of rotation (20) is arranged in a zone (18) between the backside (19) of the cover (3) and the impeller (12), characterised in that the air conducting means (7, 7') has at least one air conducting web (10) arranged in the region of the air suction opening (6) and a flow guiding means (21) arranged on the backside (19) of the cover (3).
2. The ventilator according to claim 1, characterised in that the air conducting means (7) provides at least one retaining web (9) supporting the air conducting web (10).
3. The ventilator according to claim 2, characterised in that the air conducting web (10) and/or the retaining web (9) are held in a frame (8).
4. The ventilator according to any one of the preceding claims, characterised in that the air conducting web (10) proceeds, at least in certain regions, linearly, obliquely, in the form of an arc, in the form of a star or in a meandering fashion.
5. The ventilator according to any one of the preceding claims, characterised in that the air conducting web (10) is profiled.
6. The ventilator according to any one of the preceding claims, characterised in that the air conducting web (10) leads into a support element (32).
7. The ventilator according to any one of the preceding claims, characterised in that the flow guiding means (21) has at least one flow guiding web (24) and/or flow guiding structure that is, at least in certain regions, formed on the backside (19) of the cover (3).
8. The ventilator according to any one of the preceding claims, characterised in that the flow guiding web (24) is a flow guiding rib (25) or a row of pins (36).
9. The ventilator according to claim 7 or 8, characterised in that the flow guiding web (24) has a constant height, or an increasing, in particular continuously increasing height.
10. The ventilator according to any one of claims 7 to 9, characterised in that the flow guiding web (24) has a straight or a curved extension.
11. Ventilator according to any one of claims 8 to 10, characterised in that the flow guiding rib (25) proceeds continuously or is interrupted in some regions.
12. The ventilator according to any one of claims 7 to 11, characterised in that the flow guiding web (24) has at least one air passage (39).
13. The ventilator according to any one of claims 7 to 12, characterised in that the flow guiding web (24) is profiled in at least some regions.
14. The ventilator according to any one of claims 7 to 13, characterised in that the flow guiding structure has dimples, riblets and/or winglets.

Images