WO2011038884A1

WO2011038884A1 - Cross-flow fan

Info

Publication number: WO2011038884A1
Application number: PCT/EP2010/005906
Authority: WO
Inventors: Harald Schmid; Georg Eimer; Arno Karwath; Werner Haas; Gerald Hogg; Nicolas Zieboll; Serkan Poyraz; Tobias Maier; Siegfried Seidler; Matthias Weiss; Michael Schmitz; Stefan Schneider; Rainer Strohm; Martin Müller; Richard Kienzler; Wolfgang Laufer; Björn WINTER
Original assignee: Ebm-Papst St. Georgen Gmbh & Co. Kg
Priority date: 2009-10-03
Filing date: 2010-09-28
Publication date: 2011-04-07
Also published as: DE202010013785U1

Abstract

The invention relates to a cross-flow fan having a bearing tube (92) and an air duct (50), which has an air inlet (44), an air outlet (52), an outer wall (48) and an inner wall (56). The cross-flow fan further comprises an external rotor motor (75) with an internal stator (100) and an external rotor (72). The internal stator (100) is connected to the bearing tube (92), and the external rotor (72) has a shaft (90) which is mounted in the bearing tube (92). Furthermore, the cross-flow fan has an impeller (66) which is provided with blades (58) which are arranged on a supporting structure (54) which has a drive connection to the external rotor (72) and which forms the inner wall (56) of the air duct (50), into which air duct (50) the blades (58) of the impeller (66) extend. The cross-flow fan has balancing pockets (62, 76), which are accessible from the pressure side of the impeller (66) and of which a first plurality (76) is arranged on the inner side of the impeller (66) in a first plane in the vicinity of the air inlet (44), and of which a second plurality (62) is arranged on the inner side of the impeller (66) in a second plane in the vicinity of the air outlet (52), in order to permit balancing of the impeller (66) in both planes from the same side (52) of the impeller (66).

Description

Diagonal fan

The invention relates to a diagonal fan, which is often referred to as a diagonal fan. Such fans have favorable characteristics, because they are compact and have a high air flow, so they are particularly suitable for cooling tasks.

It is therefore an object of the invention to provide a new diagonal fan.

According to the invention, this object is achieved by the subject matter of claim 1. The fact that the balancing pockets for both levels are accessible from the inside of the impeller, the balancing is facilitated, and the outside of the impeller remains free for the attachment of the fan blades and possibly for the installation of an additional fan assembly, which provides improved cooling of the drive motor for the

Diagonal fan and thereby increased fan power allows. Also results in a noise reduction.

Due to the balancing inside the impeller, the outside of which remains free, which is why there the air flow is not hindered by balancing pockets or the like. And thus you can extend the wings further towards the inlet side. As a result, the fan is improved ventilation technology.

The fan blades can therefore extend over a large area of the outside of the impeller, which supports the pressure build-up in the air duct of the diagonal fan and improves its performance.

A possibly provided additional fan assembly in the interior of the impeller serves to increase the fan power, because it significantly improves the cooling of the external rotor motor. It causes a cooling air flow from the outlet side of the fan through the Drive motor to the inlet side. Since the fan blades over a large part of the

Carry support structure, obtained at the outlet of such an additional fan assembly, a low suction pressure, which additionally increases the cooling air flow through the external rotor motor and therefore allows better use of this engine.

Since an additional fan assembly can be arranged at a point of the impeller on which it hardly affects the flow through the air duct, results in increased overhead fan with little additional effort.

Further details and advantageous developments of the invention will become apparent from the following described and illustrated in the drawings, in no way as a limitation of the invention to be understood embodiments, and from the dependent claims. It shows:

1 is a perspective view of a diagonal fan,

2 is a longitudinal section, taken along the line II-II of FIG. 1,

3 is an exploded view of the fan according to Figures 1 and 2,

4 is a three-dimensional view of the impeller, in section,

5 shows a longitudinal section through the bearing tube and the Nachleitapparat,

6 is a view, seen in the direction of arrow VI of FIG. 1,

7 is a plan view, as seen in the direction of arrow VII of FIG. 6,

8 shows a variant in which instead of a stationary housing, a rotating housing is used, which is connected to the tips of the fan blades, as seen from the suction side 44 of the fan, Fig. 9 is an illustration of the fan of Fig. 8, but seen from the pressure side; the drive motor and the parts for storage are not shown in FIG. 9 and are identical to FIGS. 2 and 3,

10 is a view analogous to FIG. 7,

1 1 shows a detail of the illustration of FIG. 1 0,

FIG. 12 shows a variant of FIG. 7; FIG. the difference lies in the greater number of

Fan blades 48 and their arrangement on the rotor,

13 is a section through the fan of FIG. 12, in three-dimensional view,

Fig. 14 is a perspective view of the impeller of a diagonal fan; between the main wings of the impeller auxiliary wings are arranged,

1 5 is a longitudinal section through the impeller of Fig. 14,

Fig. 16 is a plan view of the impeller of Figures 14 and 1 5, seen from the

Pressure side,

17 is a three-dimensional view of the impeller of Figures 14 to 1 6, viewed from the pressure side and in longitudinal section,

Fig. 18 is a schematic, perspective view of an axially divided impeller

66 ', which is provided on its periphery with a Venturigehäuse,

19 is a longitudinal section through the impeller 66 'of FIG. 18,

FIG. 20 is a perspective view of the impeller of FIGS. 18 and 19 in FIG

assembled state, seen from the suction side, 21 is a perspective view of the impeller of FIGS. 18 to 20, seen from the pressure side,

22 is an exploded perspective view of the impeller of Figures 18 to 21, viewed from the pressure side,

Fig. 23 is a perspective view of another embodiment of the impeller

66 "of a diagonal fan, in which the wings on its periphery are not provided with a venturi housing,

Fig. 24 is a perspective view of the impeller 66 "of Fig. 23 mounted in the

Status,

Fig. 25 shows the representation of the axial housing of a diagonal fan; this

Axial housing has an insert 46, which gives the air duct the course that is required for a diagonal fan,

26 is an illustration of the attachment of the insert by snapping,

27 shows an insert 46 for an axial housing, partly in plan view, partly in longitudinal section,

28 shows a variant of FIG. 25 or 26, in which the actual axial housing only has the shape of a relatively short ring 42 '; this ring has a conical recess in which an insert 46 'is fixed, whose inner wall 68' is frusto-conical, and

Fig. 29 is an illustration of the insert 46 'of Fig. 28; the bet is up in the

Longitudinal section and shown below in plan view.

In the following description, terms such as left, right, top, bottom refer to the figure in question. Like or similar parts are designated by the same reference numerals and usually described only once. Fig. 1 shows a perspective view of a diagonal fan 40 according to the present application, and Fig. 2 shows this fan in longitudinal section.

The fan 40 has an axial housing 42 made of metal, inside which a plastic part 46 is mounted on the inlet side 44. This forms the outer wall 48 of an air passage 50 which extends obliquely outwardly from an inlet 44 to an outlet 52.

The inner wall 56 of the air channel 50 is formed by an approximately dome-shaped or spherical cap-shaped support structure 54 (FIG. 2), on which inner wall 56 fan blades 58 are fastened, the shape of which is particularly apparent from FIG. These rotate in the direction of an arrow 60, that is, with reference to FIG. 1, in the clockwise direction.

The support structure 54 has in Fig. 2 below an approximately cylindrical portion 60, on the inside of balancing pockets 62 are provided for a first balance plane. In these pockets 62 so-called balancing weights (not shown) are inserted in the balancing process. Fig. 4 shows these pockets 62 particularly clear.

The wings 58 are formed overlapping. Together with the support structure 54, they form the impeller 66 of the fan 40. The impeller is preferably made by plastic molding. The following describes variants which are particularly favorable for the production of this complicated component.

On its inner side 68, the impeller 66 has a cylindrical extension 70, cf. Fig. 4, in which the magnetic yoke 72 of an external rotor motor 75 is attached.

This cylindrical extension 70 merges above via an annular connecting part 74 into the carrying structure 54 of the impeller 66.

In the connecting part 74 are balancing pockets 76 of a second balancing plane

provided which have an axial distance from the pockets 62. They allow for balancing in two planes from the same side of the impeller 66.

Such a structure of the fan 40 thus allows the balancing of the impeller 66 from a single side, namely the lower side in FIG. 2, so that on the outside 56 of the Carrying structure 54 no balancing pockets must be provided. This allows an optimal design of the support structure 54 and the fan blades 58, the radially inner ends may be closer to the axis of rotation 78 of the impeller 66, which brings noise advantages, ie the so-called connection surface of the fan blades 58 on the

Carrying structure 54 of the impeller 66 may be particularly large here, and also improves the aerodynamic efficiency.

Also, the fan blades 58 may have at their inlet an S-profile 80, which is best seen in Fig. 1, and they may indentations 82, which also for

Reduces fan noise contributes.

As Fig. 4 shows particularly clearly, between the cylindrical extension 70 and the cylindrical portion 60 many stiffening elements 83 are provided which reinforce the impeller 66 and prevent it from changing its shape during operation. This allows the use of a small air gap 84 between the outer wall 48 of the air duct 50 and the tips of the vanes 58, cf. Fig. 2.

The fan 40 is the electronically commutated external rotor motor (ECM) 75th

driven. The magnetic yoke 72 of the rotor 75 is, as described, connected to the cylindrical extension 70 of the connecting part 74. He is in turn with a shaft 90 in drive connection, which is mounted in a bearing tube 92, here by means of two ball bearings 94, 96 which are braced against each other by means of a compression spring 98. The magnetic yoke 72 rotates about the axis of rotation 78 during operation.

The motor 75 has an inner stator 1 00, which is mounted on the outside of the bearing tube 92. Below the Innenstators 1 00 is a printed circuit board 1 02, are arranged on the electronic components 104 for the motor 75. The bearing tube 92 is connected to a flange plate 106, which in turn is attached in a Nachleitapparat 1 1 0.

The purpose of the Nachleitapparats 1 1 0 is as follows: The air that exits during operation of the outlet 52 of the air channel 50, has a strong rotational component, which is referred to as a twist. This swirl does not contribute to the dynamic pressure, and therefore the Nachleitapparat 1 10 some stationary air guide elements (blades) 1 1 2, whose task is to calm the effluent from the outlet 52 air and thereby increase the back pressure and a calm air flow produce. Such a Nachleitapparat may possibly also be provided on the suction side 44 of the fan. In this case, the Nachleitapparat 1 1 0 is preferably adapted to the impeller 66 used, for example by adaptation to the shape of the air channel 50 in order to achieve at the outlet 52 a well-suited for cooling form of air flow. The Nachleitapparat 1 10 also serves as a carrier for the (not shown)

Connection cable of the engine 75. The number of its blades 1 1 2 hangs u.a. on the size of the fan 40 from.

The air guide elements 1 1 2 extend transversely to the air outlet 52 between a

Outer ring 1 14 and an inner ring 1 1 6.

The outer ring 1 14 is fixed to a flange 1 18 on the air outlet side 52 of the housing 42, and on the inner ring 1 1 6, the flange 106 is fixed, i. at this

Embodiment, the air guide elements 1 1 2 also have the function, the

External rotor motor 75 and the impeller 66 to wear. Because of its simple shape and multiple function, the Nachleitapparat is cost-neutral, but brings a noticeable improvement in the fan.

In practice, bearing tube 92, flange 106, trailing 1 1 0 and axial housing 42 can be executed as a one-piece aluminum die-cast part or as a one-piece plastic part.

Since the external rotor motor 75 is disposed inside the support structure 54, it is relatively poorly cooled. Therefore, an additional fan assembly 120 is provided in the manner of a disc above the motor 75 in FIGS. 1 to 3, which is driven directly by the shaft 90 here. It sits directly on the outer rotor 72 and sucks air through openings 122 which are provided in the cup-shaped part 72, see. Fig. 3.

This air first flows through the motor 75 and thereby cools it. In operation, the diagonal fan 40 of FIG. 2 has a pressure P1 at the top and a higher pressure P2 at the bottom, which pushes the air upwardly through the motor 75, thereby cooling it.

From the motor 75, the cooling air flows through the opening 1 22 (Fig. 3) of the cup-shaped member 72 to the inlet of the air disc 1 20, which is formed as a radial fan wheel. This supports the action of the pressure P2 and sucks air through the openings 122.

The air disc 1 20 can either be made directly on the impeller 66 during its manufacture, e.g. by injection molding, or it can be grown on the impeller 66.

In the present case, 1 20 projections 1 23 (Figure 4) are provided on the air disc, and these are inserted through holes 1 22 (Figure 3) in the part 72 and there, e.g. welded by ultrasound. For complicated wheels 66 that is advantageous.

From the air disk 120, the cooling air is blown radially through outlet openings 126 (FIGS. 2, 4).

The diagonal fan 40 has on its air inlet side 44 in the region of the disc 1 20 a low pressure P4, which is usually slightly lower than the pressure P1, since from there the air is sucked to the inlet opening 44.

This sucked air flows through the outlet openings 126 and generates there by the Venturi effect an additional negative pressure, which amplifies the flow of cooling air through the motor 75, thereby further improving the cooling of the motor 75.

In the language of physiology, therefore, the cooling air flow is driven by the motor 75 on the one hand by the vis a tergo, namely the pressure P2, and on the other by three types of vis a fronte, namely once the suction of the rotating disc 1 20, ie

vis a fronte I,

Furthermore, by the low pressure in the upper side of the disc 120, so vis a fronte II, and by the negative pressure (venturi effect), which is caused by the air flowing into the intake port 44, which flows over the outlet openings 1 26 and there by the Venturi effect reduces the pressure, ie

vis a fronte III.

Since no balancing pockets are provided on the outside of the impeller 66, there is an air flow that is not disturbed by obstacles, and the roots of the vanes 58 can be pulled up far, improving fan performance and reducing fan noise.

As shown in FIG. 4, the additional fan assembly 120 is formed as a radial fan and has radial fan blades 1 24 which draw air in the axial direction through the openings 122 (FIG. 3) and then blow out radially through outlet openings 126. Since the inlet opening 44 of the impeller 66 is at the location of the outlet openings 1 26, there is a low pressure, so that the air flow through the external rotor motor 75 is sufficiently large to cool this well.

In addition, the disc 1 20 also serves as protection, which closes in Figs. 1 to 3, the upper side of the impeller 66 and also serves as a mechanical fuse for the radially inner ends of the fan blades 58.

Fig. 5 shows a section through the bearing tube 92 and the Nachleitapparat 1 1 0. The flange 1 06, on which the bearing tube 92 is arranged, is fixed in the ring 1 1 6 of the Nachleitapparats 1 1 0, e.g. by welding, screwing, gluing or the like. The blades 1 12 of the Nachleitapparats 1 1 0 are designed so that they deflected air 130, which rotates in the direction of rotation 60, in the axial direction 1 32 and thereby the usable

Increase airflow.

(The flow direction of the air rotating in the direction of rotation 60 is to be considered in the lower part in Fig. 5 so that the air comes out of the drawing plane and in the upper part so that the air enters the drawing plane symbolized at 130 by an arrowhead, and at the top by the end of an arrow.) Fig. 6 shows a view of the fan, as seen in the direction of arrow VI of Fig. 1. It can be seen the course of the five blades 1 1 2 of the Nachleitapparats 1 1 0, which also have the function of the impeller 66 and the motor 75 to wear. In addition, you can see the location of the nine fan blades 58, which rotate in the direction of arrow 60 in operation.

Fig. 7 shows a plan view of the impeller 66, seen in the direction of arrow VII of FIG. 4, ie without the motor 75. The balancing pockets 62 and 76 of the two balancing planes are shown, as are the six stiffening elements 83, the nine fan blades 58, and the radial fan blades 1 24 of the additional fan assembly 1 20 provided for cooling the motor 75 (FIG. 2).

FIGS. 8 to 11 show a variant of the diagonal fan according to FIGS. 1 to 7. In this variant, a stationary axial housing (42 in FIGS. 1 and 2) is not necessarily used, but this variant uses a "rotating housing" 136. namely, a kind of lower abdominal bandage which extends around the fan blades 58 and is connected to the outer ends thereof, as shown particularly clearly in Fig. 11 The rotary housing 36 has approximately the shape of a hollow truncated cone designate rotating venturi arrangement.

The inner structure (within the support structure 54) is consistent with Figs. 1 to 7 and therefore will not be described again.

As Fig. 1 1 shows well, the wings 58 are preferably integral with the rotating

Housing 136 formed, i. their outer ends are connected to the rotating housing 1 36. As a result, no air losses occur at the wing tips, which reduces the noise of such a fan, and improves the efficiency.

In some cases, a stationary housing (analogous to the housing 42 of FIGS. 1 to 6) may be provided around the rotating housing 36, the housing 136 being surrounded by the housing 42 with a small gap such that the air flow from the pressure side 52 of the fan to the suction side 44 is further reduced. It is advantageous that the wings 48 can hardly deform during operation, so you can work with very small tolerances. In this case can also be a Nachleitapparat (Analogous to the Nachleitapparat 1 1 0 of Fig. 3, 5 and 6) are provided in order to reduce the swirl of the outflowing air.

Fig. 1 2 shows a fan with a rotating housing 1 36, in which 1 6 fan blades 58 are provided. These are arranged at irregular intervals for noise reduction. Incidentally, the arrangement is consistent with FIG. 10.

FIG. 1 3 shows a section through the fan of FIG. 12, in a three-dimensional view analogous to FIG. 11. The advantage of the rotary housing 136 is that, in such an arrangement, the vanes 58 will not deform much during operation, and losses due to flow from the outlet 52 to the inlet 44 will be greatly reduced. This is particularly true when the impeller 66 rotates in a housing (not shown) which is e.g. may look like the axial housing 42 of FIGS. 1 and 2.

Again, an additional fan assembly 120 is provided, which is attached to a (not shown) drive motor (analogous to the drive motor 75 of FIG. 2) and rotates with this. The radial fan blades 124 are provided for this purpose with projections 1 23, which through holes 1 22 (Fig. 3) in the magnetic yoke 72nd

be plugged through and welded there.

14 to 1 7 show the impeller 66 of a diagonal fan 140. The impeller 66 has eight main blades 1 58, which are mounted on the outside of the spherical cap-shaped support structure 54 and extending there up to the openings 1 26. These vanes 1 58 are arranged overlapping, and their front in the direction of rotation edges have an S-profile 1 80, and they have indentations 182. These indentations affect the secondary flow at the wings in a positive manner.

The roots of the wings 1 58 extend up to the lower edge of the support structure 54 in FIGS. 1 and 15. In the lower region of the support structure 54, auxiliary blades (splitter blades) 1 59 are arranged between the main wings 1 58, whose roots likewise extend to the lower edge of the support structure 54 in FIGS. 14 and 15, but only up to about the middle of the height of the support structure 54 upwards. These auxiliary wings or auxiliary blades 1 59 improve the performance of the diagonal fan. They increase the effective area of the fan blades, and this results in a higher aerodynamic efficiency. The shape of the auxiliary blades is chosen so that the fan noise is as small as possible.

The fan according to FIGS. 14 to 17 likewise provides an additional radial fan 120, as has already been described in FIGS. 1, 2, 4 and 7. This serves to cool the drive motor 75 (FIG. 2) and its electronics. Its radial fan blades 1 24 have extensions 1 23, which serve for attachment to the outer rotor 72 of the drive motor 75.

Fig. 18 shows a variant of a two-part impeller 66 ', which is provided with a rotating housing 1 36', which is also known as a rotating Venturianordnung 136 '.

can denote. (Such is also used in Figs. 8 to 11). Such an impeller is difficult to produce by casting or injection molding in a single piece, and therefore, in Fig. 18, the impeller 66 'is axially divided.

The impeller 66 'of Fig. 18 has eight main wings 58, whose attachment to the

Carrying structure 54 extends to the openings 1 26, and between these eight main wings 58 are eight auxiliary wings 59th

The wings 58, 59 overlap each other. The vanes 58 have an S-profile 80 at their inlet, and they have indentations 82. All vanes are connected to the venturi 136 ', so that their shape can not change much with the fan rotating, and this allows the use of a very small one Air gap between the

Venturi assembly 136 'and the non-rotating axial housing (not shown), e.g. at 42 in Fig. 1 and 2 is shown.

Fig. 19 shows the impeller 66 'of Fig. 1 8 in the assembled state and in the

Longitudinal section. The dividing line is designated 200. Along this parting line 200, the two halves of the impeller are connected to each other, for example, by mating, gluing, welding, etc. Fig. 20 shows the impeller 66 'of Figs. 18 and 19, also in assembled condition and in perspective. The parting line is also designated here by 200. The location of one of the auxiliary wings 59 is clearly visible. Also, one recognizes the truncated cone shape of Venturianordnung 1 36 ', which is particularly well suited for a diagonal fan.

Fig. 21 shows the impeller 66 'of Fig. 18 to 20, seen from the pressure side 52. One recognizes the total of 1 6 fan blades. The support walls 83 are also divided in the axial direction.

FIG. 22 shows the impeller 66 'in an exploded view, the connections being shown separated from the vanes 58, 59 to the venturi 136'. The

Representation of FIG. 22 serves to make the shape and position of the wings 58 and 59 clearly visible and understandable. The parting line 200 is shown only on the Venturianordnung 136 '.

Figures 23 and 24 show that the axial pitch of an impeller 66 "is possible even without the use of a venturi arrangement (cf the arrangement 136 'of Figures 18 to 22), especially if the vanes 58 used have a very complicated shape.

Particularly suitable here are wheels with thick wings, which deform only slightly during operation, as is the case in FIGS. 23 and 24.

The dividing line is here designated by 200 '. Without such an axial separation, the impeller 66 "would be very difficult and high cost to produce because of the irregular and strongly overlapping shape of the wings 58.

Fig. 25 shows an axial housing 42 analogous to the axial housing 42 of FIG. 2, which is shown there only schematically.

As shown in Fig. 2, between the impeller 66 and the inner wall 48 of the axial housing 42, only a small air gap 84 should be present. This makes it necessary there, the motor 75 and the impeller 66 from the pressure side 52 ago in the

Insert axial housing 42. This complicates the assembly. The version according to FIGS. 25 to 27 allows mounting from the suction side 44.

25 and 26, the axial housing 42 receives a cylindrical inner wall 47, and in this after insertion of the motor 75 and the impeller 66 from the suction side 44 forth insert 46 is fixed and secured, for. by snapping or gluing, and this insert 46 is sized so that between the tips of the wings 58 and the inner wall 48 of the insert 46 remains an air gap 84 of the desired size, which is as small as possible. In this way, the assembly is greatly facilitated in a diagonal fan, since the axial housing 42, the trailing device 1 1 0, the flange 106 and the bearing tube 92 can be fully assembled with the stator 100. The impeller 66 is then inserted from the suction side 44 into this preassembled component, and only then, as a conclusion, is the insert 46 inserted from the suction side 44, as shown in FIGS. 25 and 26.

Fig. 27 shows the insert 46, top in longitudinal section, bottom in the plan view. He has on the side 44 a flange 45, which bears in the manner shown in FIGS. 25 and 26 against the axial housing 42. On its outside, the insert 46 is provided with reinforcing ribs 49.

Fig. 26 shows a preferred example of a lock. For this purpose, the axial housing 42 in its cylindrical inner wall 47 latching recesses 47 A, and the insert 46 has on its outer side latching projections 46 A, which engage in these recesses 47 A after assembly and thereby hold the insert 46 in the axial housing 42. Naturally, the latching recesses could also be provided on the outside of the insert 46, and the latching projections would then be located on the inner wall 47.

FIG. 28 shows a very advantageous variant, in which the axial housing has shrunk to a relatively short ring 42 ', which on its side facing the suction side 44 is provided with a hollow frustoconical recess 208. In this recess 208 a complementary end 21 0 of an insert 46 'is attached. The latter extends from there toward the suction side 44, and the diameter of its inner side 68 'decreases in the direction of the suction side 44, so that the distance 84 to the tips of only shown schematically wings 58 can be very small. This variant allows a particularly simple installation, since the impeller 66 is freely accessible during its assembly, and the insert 46 'is mounted only after installation of the impeller 66.

Fig. 29 shows the insert 46 ', top in longitudinal section and bottom in plan view. The attachment to the ring 42 'may e.g. by gluing, welding or by a

Latching connection analogous to Fig. 26 done.

Of course, the various embodiments may be combined as needed. For example, For example, the reinforcing ribs 49 shown in FIG. 27 may also be used in the insert 46 'of FIG. 29. Even otherwise, many modifications and modifications are possible within the scope of the present invention.

Claims

claims

Diagonal fan, which has:

A bearing tube (92);

an air duct (50) having an air inlet (44) and an air outlet (52) and having an outer wall (48) and an inner wall (56);

an external rotor motor (75) having an inner stator (100) and an outer rotor

(72)

- Which inner stator (100) is connected to the bearing tube (92) and

- Which outer rotor (72) has a shaft (90) which is rotatably mounted in the bearing tube (92);

an impeller (66) provided with vanes (58), which at one with the

Outer rotor (72) are disposed in drive-connected support structure (54), the latter forming the inner wall (56) of the air duct (50), in which air duct (50) the wings (58) of the impeller (66) extend;

Balancing pockets (62, 76) accessible from the pressure side of the impeller (66) and having a first plurality (76) on the inside of the impeller (66) in a first plane near the air inlet (44)

and of which a second plurality (62) is disposed on the inside of the impeller (66) in a second plane near the air outlet (52),

to allow balancing of the impeller (66) in both planes from the same side of the impeller (66).

Diagonal fan according to claim 1, wherein on the air inlet (44) facing side of the impeller (66) an additional fan assembly (1 20) is provided, which is adapted to operate air through the

External rotor motor (75) to transport.

The diagonal fan of claim 2, wherein the additional fan assembly (120) is configured in the manner of a radial fan (124) and arranged to draw air through the outer rotor motor (75) during operation.

4. Diagonal fan according to one of the preceding claims, wherein for the preparation of the drive connection between the motor (75) and the impeller (66), a connecting member (74) is provided,

and the balancing pockets (76) of one plane are provided on this link (74).

5. A diagonal fan according to claim 4, wherein the balancing pockets (76) on the radially outer side of the connecting member (74) are provided.

6. A diagonal fan according to claim 4 or 5, wherein the connecting member (74) on its the outer rotor (72) facing side (70) is connected to an outer portion of the outer rotor (72),

and stiffening elements (83) are provided, which connect the motor-side portion of the connecting member (74) with the support structure (54) of the impeller (66).

7. Diagonal fan according to one of the preceding claims, wherein the

Carrying structure (54) of the impeller (66) has approximately the shape of a dome.

A diagonal fan according to claim 7, wherein the dome has a large diameter portion (60) from which its diameter decreases,

and wherein the dome is formed at its portion (60) of large diameter at least partially in the manner of a hollow cylinder.

9. Diagonal fan according to claim 8, wherein the balancing pockets (62) of one of the two levels on the inside of this hollow cylinder (60) are arranged.

1 0. A diagonal fan according to any one of the preceding claims, wherein the impeller (66) is molded from plastic.

1 1. A diagonal fan according to any one of the preceding claims, wherein the

Fan blades (58) overlapping on the support structure (54) of the impeller (66) are arranged.

2. Diagonal fan according to one of the preceding claims, wherein between the fan blades (58, 158) additional fan blades (1 59), so-called splitter on the

Carrying structure (54) of the impeller (66) are arranged. 3. Diagonal fan according to one of the preceding claims, in which the

Fan blades (1 58) are wound wound. 4. Diagonal fan according to one of the preceding claims, in which the

Fan blades (58, 1 58) on its seen in the direction of rotation front side (180) have an approximately S-shaped curve (80, 180). 5. Diagonal fan according to one of the preceding claims, wherein on the

Outlet side (52) of the air channel (50) a Nachleitapparat (1 1 0) for the air flowing from the fan (40) air flow (132) is provided. 6. Diagonal fan according to claim 1 5, wherein the Nachleitapparat (1 1 0) as part of a connection between the bearing tube (92) and a stationary support member (1 18) is formed. 7. Diagonal fan according to claim 16, wherein on the outside of the air duct (50) an axial housing (42, 42 ') is provided, which is connected to the Nachleitapparat (1 1 0) and the bearing tube (92), to which latter the Drive motor (75) and the impeller (66) are arranged,

and on the inner side (47; 208) of the axial housing (42; 42 ') an insert (46) is fixed, in which the diameter of the inner side (48; 68') decreases in the direction of the suction side (44) of the fan. 8. Diagonal fan according to claim 17, wherein the transition from the inside of the insert (46, 46 ') to the inside (47, 208) of the axial housing (42, 42') is formed with low steps.

A diagonal fan as claimed in any one of the preceding claims, wherein the fan blades (58) of the impeller (66) are externally connected to a ring (1 36; 136 ') which extends around the impeller (66).

A diagonal fan as claimed in any one of the preceding claims, wherein the impeller (66 ', 66 ") is composed of two or more parts.