EP3789617A1 - Ventilator - Google Patents

Abstract

Fan with at least one electric motor and aerodynamically effective components or elements, which comprise at least one impeller equipped with blades, with some of the aerodynamically effective components or elements due to their arrangement or orientation mainly in one conveying direction and another part of the aerodynamically effective ones for the reversibility of the conveying direction Components or elements can mainly be assigned to the other opposite conveying direction due to its arrangement or orientation.

Description

The invention relates to a fan with at least one electric motor and aerodynamically effective components or elements. The aerodynamically effective components or elements include at least one impeller equipped with blades. A reversal of the air conveying direction should be possible.

In numerous fan applications, fan operation with alternating conveying directions is required, if possible with high outputs and efficiencies for both conveying directions. Fan impellers designed for high air capacities and high levels of efficiency are generally not suitable to be operated in both directions of rotation if the air output and efficiency are sufficiently good. Consequently, such fan impellers are ruled out for such applications.

Special impeller geometries which are symmetrical with respect to the direction of rotation are known from practice. These are basically suitable for reversing operation, but have efficiencies that are not competitive for operation in a preferred direction.

• Laufräder bzw. Flügel mit symmetrischer, reversierbarer Geometrie, beispielsweise mit im Querschnitt S-förmigen Flügeln;
• Realisierung eines Reversierbetriebs mit parallelen Ventilatoren, meist unter Einsatz ansteuerbarer Verschlussklappen;
• Betrieb eines Ventilators mit Vorzugsdrehrichtung als Reversierlüfter, stets unter Akzeptanz schlechter Wirkungsgrade für die nicht bevorzugte Förder- /Drehrichtung;
• Realisierung eines Reversierbetriebs mittels mechanischem "Umschwenken" eines Ventilators, mit erheblichem mechanischem Aufwand und
• Realisierung eines Reversierbetriebs durch Klappenumstellungen in einem Luftführungssystem.

The prior art known from practice provides the following approaches:

• Impellers or blades with symmetrical, reversible geometry, for example with blades with an S-shaped cross-section;
• Realization of reversing operation with parallel fans, mostly using controllable closing flaps;
• Operation of a fan with a preferred direction of rotation as a reversible fan, always accepting poor efficiencies for the non-preferred conveying / direction of rotation;
• Realization of a reversing operation by means of mechanical "swiveling" of a fan, with considerable mechanical effort and
• Realization of a reversing operation by changing flaps in an air duct system.

Regarding the state of the art in printed literature, in particular with regard to the provision of two independent fans for the optional reversal of the air conveying direction, reference is only made to FIG US 2014/363272 A referenced. The design there is, however, disproportionately complex in terms of construction.

The present invention is based on the object of creating a fan suitable for reversing operation, regardless of the type, which is suitable for conveying in both conveying directions with high degrees of efficiency. It should be possible to use aerodynamically effective components or elements, in particular impellers or blades, which are used in fans with high efficiencies with preferred directions of rotation. Shutters or other additional components should not be required. In addition, the design of such a fan should differ from competitive fans.

The above object is achieved by the features of claim 1. According to this, the generic fan is designed and developed in such a way that, in order to reverse the air conveying direction, at least some of the aerodynamically effective components or elements are mainly arranged or aligned for one conveying direction and another part of the aerodynamically effective components or elements is mainly arranged or oriented for the other conveying direction . The aerodynamically effective components or elements are designed and arranged in such a way that they work together in both conveying directions with high levels of efficiency, with either the direction of rotation of one or more motors being changed and / or motors being switched on or off to reverse the air conveying direction that are responsible for the direction of rotation of the aerodynamically effective components or elements. All impellers of the fan have a common axis of rotation. As a result, the fan is very compact in directions transverse to this axis.

In the context of a simple embodiment of the teaching according to the invention, it is conceivable that the direction of rotation of the impeller can be reversed in order to reverse the air conveying direction. Some of the aerodynamically effective components or elements are arranged mainly designed for one direction of rotation and another part of the aerodynamically effective components or elements is arranged mainly for the other direction of rotation. It can be, for example, a Act reversible axial fan whose impeller is constructed with geometrically identical or similar individual blades, which are installed in pairs alternately oriented for one and the other conveying direction.

Specifically, to change the direction of rotation of the impeller, the direction of rotation of the motor can be changed and / or the motors responsible for the respective direction of rotation can be switched on and off.

The impeller is equipped with vanes optimized for the respective direction of travel, as is the case with vanes or impellers optimized in one conveying direction. The impeller is optimized in terms of the vane angle and / or the vane or impeller design. It is also conceivable that the vane angle is adjustable or adjustable on the impeller.

In a particularly advantageous manner, the blades are arranged alternately rotated for one and the other running direction, in particular alternately by 180 ° with respect to a transverse axis, preferably to a transverse axis orthogonal to the fan or motor axis.

The angular position of the wings can be identical for the wings that can be assigned to the two conveying directions, or differently set or adjustable as required. An optimal adaptation to the requirements existing in both conveying directions is possible.

In the context of a further variant, it is possible that at least two identical or different running wheels equipped with blades are provided, which are arranged one behind the other in the conveying direction and connected to one another in a rotationally fixed manner. The two running wheels are rotated by 180 ° to one another with respect to a transverse axis or radial axis. Here, too, the wing angles can be designed differently if necessary. The same applies to the impeller design. A needs-based adjustment or coordination is possible.

Another embodiment of the teaching according to the invention results from the fact that two partial fan units are arranged one behind the other in the conveying direction, each of which includes at least one impeller and possibly a housing or housing part.

The two partial fan units are rotated by 180 ° to one another with respect to a transverse axis or radial axis. However, a common motor can be provided for both partial fan units. Each partial fan unit can also have a separate drive or motor. The two partial fan units can each be operated for one conveying direction.

In a particularly advantageous manner, it is possible for the impeller of the partial fan unit connected downstream in the conveying direction to rotate without a drive. This drive-free rotating impeller can be used for volume flow measurement.

It is conceivable that the speeds of the impellers of the two partial fan units are synchronized. It is also conceivable that, advantageously dependent on the operating point, the two speeds are coordinated with one another in such a way that the efficiency is as high as possible or the generation of noise is as small as possible.

It is also conceivable that the impeller, which rotates without a drive, is operated as a generator at least for a preferably definable operating range. The energy / power obtained as a generator can be transferred electrically to the respective other motor, for example via an intermediate circuit, or mechanically, for example via a mechanical coupling or a shaft connection.

At least part of the energy / power obtained as a generator can also be fed into the power grid.

In a particularly advantageous manner, the speed of the rotating impeller can be monitored and used to regulate the driven partial fan unit. Such a regulation is used, for example, to avoid excessive vibrations. This can benefit the service life of the bearing as well as the service life or fatigue strength.

Finally, it is conceivable that at least one of the partial fan units comprises holding means or a support device which, for example, can be designed as a guide device or is used to attach such a device.

Fig. 1

in perspektivischer Ansicht ein Laufrad eines erfindungsgemäßen Ventilators mit 180° Rotationssymmetrie bezüglich einer Achse quer zur Ventilatorachse, im Wesentlichen aufgebaut aus zwei Laufrädern, welche jeweils für sich gesehen keine 180° Rotationssymmetrie bezüglich einer Achse quer zur Ventilatorachse aufweisen,

Fig. 2

in einer Draufsicht von der Seite gesehen das Laufrad gemäß Fig. 1,

Fig. 3

in einer Draufsicht von der Zuström- oder Abströmseite gesehen das Laufrad gemäß Fig. 1 und 2,

Fig. 4

in perspektivischer Ansicht und in einem Schnitt an einer Ebene durch die Ventilatorachse das Laufrad gemäß Fig. 1 bis 3,

Fig. 5

in perspektivischer Ansicht ein Laufrad eines erfindungsgemäßen Ventilators mit 180° Rotationssymmetrie bezüglich einer Achse quer zur Ventilatorachse, im Wesentlichen aufgebaut aus einer Nabe und identischen Flügeln, welche jeweils für sich gesehen keine 180° Rotationssymmetrie bezüglich einer Achse quer zur Ventilatorachse aufweisen,

Fig. 6

in einer Draufsicht von der Zuström- oder Abströmseite aus gesehen das Laufrad gemäß Fig. 5,

Fig. 7

in einer Draufsicht von der Seite gesehen das Laufrad gemäß Fig. 5 und 6,

Fig. 8

in perspektivischer Ansicht einen erfindungsgemäßen Ventilator mit 180° Rotationssymmetrie bezüglich einer Achse quer zur Ventilatorachse, im Wesentlichen aufgebaut aus Laufrädern und Gehäusen mit integrierten Nachleiträdern, welche jeweils für sich gesehen keine 180° Rotationssymmetrie bezüglich einer Achse quer zur Ventilatorachse aufweisen, sowie zwei Elektromotoren,

Fig. 9

in seitlicher Ansicht und in einem Schnitt an einer Ebene durch die Ventilatorachse den Ventilator gemäß Fig. 8, und

Fig. 10

ein Diagramm, bei dem ein Vergleich von Luftleistung und Wirkungsgrad eines für eine Förderrichtung vorgesehenen Referenzventilators und eines vergleichbaren reversierbaren Ventilators dargestellt ist.

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

Fig. 1

a perspective view of an impeller of a fan according to the invention with 180 ° rotational symmetry with respect to an axis transverse to the fan axis, essentially composed of two impellers which, viewed individually, do not have 180 ° rotational symmetry with respect to an axis transverse to the fan axis,

Fig. 2

in a plan view from the side, the impeller according to FIG Fig. 1 ,

Fig. 3

in a plan view from the inflow or outflow side, the impeller according to FIG Figs. 1 and 2 ,

Fig. 4

in a perspective view and in a section on a plane through the fan axis, the impeller according to FIG Figs. 1 to 3 ,

Fig. 5

a perspective view of an impeller of a fan according to the invention with 180 ° rotational symmetry with respect to an axis transverse to the fan axis, essentially composed of a hub and identical blades, each of which, viewed individually, does not have 180 ° rotational symmetry with respect to an axis transverse to the fan axis,

Fig. 6

in a plan view from the inflow or outflow side, the impeller according to FIG Fig. 5 ,

Fig. 7

in a plan view from the side, the impeller according to FIG Figures 5 and 6 ,

Fig. 8

a perspective view of a fan according to the invention with 180 ° rotational symmetry with respect to an axis transverse to the fan axis, essentially composed of impellers and housings with integrated guide wheels, each of which, viewed individually, does not have 180 ° rotational symmetry with respect to an axis transverse to the fan axis, as well as two electric motors,

Fig. 9

in a side view and in a section on a plane through the fan axis, the fan according to Fig. 8 , and

Fig. 10

a diagram in which a comparison of air output and efficiency of a reference fan provided for one conveying direction and a comparable reversible fan is shown.

Fig. 1 shows a perspective view of an impeller 2 of a fan according to the invention with 180 ° rotational symmetry with respect to an axis transverse to the fan axis. The impeller 2 is essentially composed of two asymmetrical partial impellers 3a and 3b, each of which, viewed individually, does not have 180 ° rotational symmetry with respect to an axis transverse to the fan axis and is therefore only suitable to a limited extent for reversing operation. The partial impellers 3a and 3b have different design conveying directions, the design conveying direction of partial impeller 3a along the fan axis approximately from left to right in the illustration according to FIG Fig. 1 runs, that of partial impeller 3b runs along the fan axis approximately from right to left. The design conveying directions of the asymmetrical partial runners 3a and 3b are accordingly rotated by approximately 180 ° with respect to a transverse axis with respect to one another. In the exemplary embodiment, the impeller or the partial impellers are each constructed from a hub 7 with 9 individual blades 6 each. The wings 6 have feet 8 on which they are clamped between two hub halves 9. The hub halves are connected to one another with screws 10.

The partial impellers 3a and 3b do not have a 180 ° rotational symmetry with respect to a transverse axis. In the composite shown, however, the overall impeller 2 has such a rotational symmetry. The total impeller consists of Essentially composed of a partial impeller 3a and a partial impeller 3b rotated by 180 ° with respect to a transverse axis (radial axis), but otherwise structurally identical, which are connected to one another in a rotationally fixed manner. The named transverse axis (radial axis) runs perpendicular to the axis of rotation of the fan. The 180 ° rotational symmetry with respect to a transverse axis has the consequence that by reversing the direction of rotation of the fan, the conveying direction is reversed with essentially the same aerodynamic properties.

The trailing vane edges 12 of the vanes 6 of the partial impeller 3 a face the trailing vane edges 12 of the vanes 6 of the partial impeller 3 b. The wing leading edges 11 of the wings 6 of the partial impeller 3 a are facing away from the wing leading edges 11 of the blades 6 of the partial impeller 3 b. Depending on the direction of rotation of the total impeller 2, the air enters the impeller 2 from the right or left and first hits the leading edges 11 of the blades 6 of the partial impeller 3a or 3b. The air then flows through the area of the partial impeller 3a or 3b, passes the area of the mutually facing rear edges 12 before it leaves the impeller 2 in the area of the front edges of partial impeller 3b or 3a.

In Fig. 2 is in a side plan view of the impeller 2 according to the embodiment Fig. 1 shown. It can be seen that the two partial impellers are connected to one another in a rotationally fixed manner in the region of their hubs 7 with a connecting element 13. With a hub-motor shaft connecting element 14, the overall impeller 2 can be fastened, for example, to a motor shaft of a drive motor.

The rear edges 12 of the blades 6 of the two partial wheels 3a and 3b face each other and are very close to each other. This applies with regard to the air delivery direction (fan axis direction), but advantageously, as in the exemplary embodiment, also with regard to the circumferential direction. This minimizes aerodynamic losses, since the trailing edges 12 of the blades 6 of the downstream partial impeller 3b or 3a (depending on the direction of rotation of the fan) are approximately in the post-flow dent of the upstream blades 6 of the partial impeller 3a or 3b.

The two partial impellers 3a and 3b can, each seen individually, with good efficiency and low noise generation in a fan with one conveying direction (without reversing operation). An important advantage of the invention arises here in that identical components can be used for a fan without reversing operation, but also, if necessary, can be assembled to form a fan which is suitable for reversing operation.

However, significantly more components are required for the impeller 2 shown (blades 6, hub halves 9) and the weight is higher. At the same speed, the air delivery rate increases at least slightly in comparison to a single impeller, which only consists of a partial impeller 3a or 3b.

The stagger angle (pitch angle) of the blades 6 in the exemplary embodiment can be set before the hub halves 9 are jammed with the blade feet 8. As a result, an impeller 3a, 3b can be optimally adapted to a required operating point of an application.

It is also advantageous to design the partial runners 3a and 3b differently, for example with regard to the stagger angle settings of the respective blades, if different requirements apply to the two conveying directions. Then, strictly speaking, there is no longer a 180 ° rotational symmetry with respect to a transverse axis, since there is also no aerodynamic symmetry with respect to the conveying directions. Such a construction is nevertheless viewed as an overall impeller 2 having approximately 180 ° rotational symmetry with respect to a transverse axis.

The number of vanes 6 is advantageously identical for both partial runners 3a and 3b.

In Fig. 3 is in a plan view from an inflow or outflow direction from the overall impeller 2 of the embodiments according to Figs. 1 and 2 shown. Both partial impellers 3a and 3b are made up of 9 blades 6 each. There can be 2-13 wings 6 advantageously. The rear edges 12 of the wings 6 are designed to be corrugated or jagged in the exemplary embodiment. In the illustration on the hub / motor shaft connecting element 14, the contour of a feather key connection can be seen. The outer diameters of the two partial impellers 3a and 3b are identical. As a result, the entire impeller can have an approximately constant head gap (= Distance between the blades 6 and a housing wall in which they are installed) run in a cylindrical housing.

In Fig. 4 is a perspective view and in section on a plane through the fan axis, the overall impeller 2 of a fan according to the invention according to the Figs. 1 to 3 shown. The connecting element 14 of the hubs of the two partial runners 3a and 3b is screwed to the hubs 7 with screws 10 in the exemplary embodiment. The connecting element 14 is hollow on the inside.

It is also conceivable that an impeller 2 is driven by two motors. A hub / motor shaft connecting element 14 is then required on both hubs. The connection of the partial runners can also be done in other ways. It is also conceivable that they are connected via a motor which, for example, has an output shaft on both sides.

In Fig. 5 an impeller 2 of another embodiment of a fan according to the invention is shown in a perspective top view. In comparison to the embodiment according to FIGS Figs. 1 to 4 the impeller has only one hub 7 with the two hub halves 9. However, one half of the wings 6b is rotated by 180 ° with respect to a transverse axis to the other half of the wings 6a. The wings 6a are arranged in accordance with a conveying direction from right to left, while the wings 6b are arranged in accordance with a conveying direction from left to right. Seen in isolation, the wings 6a, 6b are asymmetrical, ie they do not have an approximately 180 ° rotational symmetry with respect to a transverse axis.

The front edges 11 of the wings 6b are accordingly more upstream of the rear edges 12 of these wings 6b with respect to an air flow direction, while the front edges 11 of the wings 6a in the illustration shown are more upstream of the rear edges 12 of these wings 6a with respect to a Direction of air flow rather from right to left.

One possible interpretation is that the impeller 2, consisting of a total of 6 blades, is a combination of two partial impellers, one being made up of the 3 blades 6b and corresponding to a conveying direction more from left to right and the other consisting of the 3 blades 6a is built and one Direction of conveyance corresponds more to right to left. In contrast to the embodiment according to the Figs. 1 to 4 However, there is only one hub 7 on which all the blades 6a, 6b are applied. For reasons of cost and weight, this is an advantage compared to the embodiment according to FIG Figs. 1 to 4 . However, it is disadvantageous that the adjacent blades 6a, 6b cannot be arranged one behind the other so favorably in terms of flow. In addition, the flexibility with regard to the number of wings is significantly less. With the hub shown with 9 receptacles 15 for wing feet, only the number of wings shown is conceivable in this type of reversible structure.

The disadvantages mentioned arise from the fact that an existing hub 7 with an even 9-fold pitch was used. A new hub body, which is especially suitable for reversing operation, can also advantageously be created for the individual vanes 6. In the case of such a hub body, the receptacles 15 have alternately smaller and larger distances from one another in the circumferential direction. In this way, the position of wings 6a and 6b assigned to one another can be better coordinated with one another. It is also conceivable that receptacles 15 always have an axial offset from one another in pairs. In the case of a hub which is used in particular for reversible running wheels, the number of receptacles 15 is accordingly advantageously an even number, since pairs of blades 6a and 6b are always arranged.

In Fig. 6 in a plan view from the inflow or outflow side, the impeller according to FIG Fig. 5 shown. In this illustration, the impeller 7 appears to be symmetrical with respect to the direction of rotation of the impeller during operation. However, the blades 6b are not mirrored blades to 6a, but are blades with the same geometric shape, which are attached to the hub 7 in pairs, each rotated by 180 ° with respect to a transverse axis. If the blades 6a, 6b are tool-bound, for example by a casting process, no new tools with mirrored contours are necessary, since the blades 6a and 6b have the same geometric shape and are only attached to the hub 7 in pairs rotated by 180 ° with respect to a transverse axis are.

In this illustration, the wing trailing edges 12 of adjacent wings 6a and 6b are aligned with one another or the distance between adjacent wing trailing edges 12 of two wings 6a and 6b is on average significantly less than the distance between adjacent wing leading edges 11 of two wings 6a and 6b. This is aerodynamically advantageous.

In Fig. 7 is a plan view from the side of the impeller according to FIG Figures 5 and 6 shown. Similar to the embodiment according to FIGS Figs. 1 to 4 Here, too, the blades 6b can be constructed at a different stagger angle with respect to the blades 6a, or even other blade geometries can be used. This is particularly advantageous when different requirements apply to the two air conveying directions. The resulting impeller is no longer exactly 180 ° rotationally symmetrical with respect to a transverse axis, but by definition this case is also to be regarded as approximately 180 ° rotationally symmetrical with respect to a transverse axis. In any case, such an impeller is also suitable for reversing operation, with high efficiencies being possible for both conveying directions.

Fig. 8 shows a perspective view of a fan 1 according to the invention for operation in both conveying directions with at least approximately 180 ° rotational symmetry with respect to an axis transverse to the fan axis. It is essentially made up of two impellers 2a and 2b (not visible here), two housings 18a and 18b with integrated motor support devices 24a and 24b, each of which is asymmetrical, i.e. does not have an approximately 180 ° rotational symmetry with respect to an axis transverse to the fan axis , as well as two electric motors. The entire fan 1 is made up of 2 asymmetrical partial fans, each of which is made up in particular of impeller 2a or 2b, housing 18a or 18b and motor support device 24a or 24b, the motor support devices 24a, 24b being designed as guide vanes at the same time. Each of the partial fans is not suitable for reversing operation, at least not with high efficiencies in both conveying directions, but suitable for operation at high efficiencies with a preferred conveying direction (with a corresponding preferred direction of rotation of the impeller).

The fact that two such asymmetrical partial fans are arranged in pairs rotated by 180 ° around a transverse axis in the manner shown is created an overall fan that has essentially 180 ° rotational symmetry to a transverse axis and is therefore suitable for reversing operation. This is essentially achieved with components that are otherwise used for fans that are optimized for a single conveying direction.

In the exemplary embodiment, the two partial fans are simply connected to one another at their original pressure-side flange 23, which thereby becomes the connecting area 23 between the partial housings 18a and 18b. The overall housing 17 is produced from the partial housings 18a, 18b.

In the exemplary embodiment, each of the partial fans has its own electric motor 4, consisting essentially of stator 20 and rotor 19 (see also Fig. 9 ). An advantageous type of operation is to actively operate only the impeller 2a or 2b, depending on the conveying direction, and to allow the impeller located downstream in each case to rotate freely. As a result, the downstream impeller can be used as a volume flow measuring device, whose speed, which can be measured, allows conclusions to be drawn about the current volume flow. With this information, the driving fan can advantageously be regulated in order to achieve a defined target volume flow.

It is possible that the freely rotating impeller rotates faster than the driving impeller, depending on the operating point. In this case, a technical control limitation of the freely rotating speed via the speed of the motor-driven impeller is advantageous.

Another operating mode is to operate both impellers at the same speed. As a result, the downstream impeller can supply power to the fluid or dissipate it from it, which is also dependent on the operating point. The simplest method of achieving speed synchronicity is to mechanically connect the two impellers to one another so that they cannot rotate, for example via a shaft. In this case, a single motor is also sufficient for the overall fan 1, which is advantageous in terms of costs.

The same speed can also be achieved in terms of control technology when using two motors. In the event that the downstream impeller of the flow Withdraws power, this power can be used sensibly on the electrical side. It can be fed back into the grid or made available to the driving motor at the level of a direct current intermediate circuit, which then draws less power from the grid.

A third operating mode is to always coordinate the speeds so that an optimal overall efficiency is achieved. In this case, the speed ratio of the two impellers is dependent on the operating point, which is consequently always recorded or estimated by measurement in such an operation.

In Fig. 9 is, seen from the side and in section on a plane through the fan axis, the fan 1 according to Fig. 8 shown. It can be seen that two partial fans that are largely functional in themselves are built into a reversible overall fan 1. The partial fans are arranged rotated by 180 ° with respect to a transverse axis and are connected to one another at the connection area 23, for example with screws. Each partial fan consists in particular of an impeller 2a or 2b with hub 7 and blades 6, housing 18a or 18b and motor support device 24a or 24b, the struts 25 of which in the exemplary embodiment are designed as flow-optimized guide vanes.

Furthermore, a motor is provided, of which the rotor 19 is connected to the impeller 2a or 2b. The stator 20 is connected to the motor support device 24a or 24b. With regard to the partial fans, the stator 20 of the motors is therefore arranged more on the outflow side, as is the electronics compartment 26 with the end covers 27 integrated in the stator 20 Embodiment a common electronics space can be created by a suitable connection cover, which can facilitate the necessary communication and, if necessary, the transfer of electrical power between the two motors.

The trailing edges 12 of the blades 6 of the impellers 2a and 2b face one another. The same applies to the trailing edges of the guide vanes 25 of the guide wheels 24a and 24b.

The inlet nozzles 5 integrated in the housing sections 18a and 18b, as well as the leading edges 11 of the blades 6 of the impellers 2a and 2b, face away from each other.
The overall housing 17 can be attached to the devices 16 for attaching the partial housings 18a, 18b to a higher-level ventilation device, an air duct, or the like. The overall fan can advantageously be attached to a higher-level system in the connection area 23.

The power and control cables 21 can be designed separately for both partial fans and controlled with a higher-level control unit. The uniform control is advantageously carried out close to the fan, either in the existing electronics rooms 26 or by means of a separate controller unit which is integrated on the overall fan.

In Fig. 10 FIG. 13 is a comparison of measurement results relating to the embodiment according to FIGS Fig. 8 and 9 shown. The static pressure increase Δp_stat (solid lines) and the static efficiency η_stat (dashed lines) are shown above the volume flow V. On the one hand for a reference fan that is intended for one conveying direction (one of the partial fans off Fig. 9 or 10 , Lines without symbols), on the other hand for the reversible overall fan according to the invention (lines with diamond symbols), the downstream fan being freely rotating in the underlying experiment. It can be seen that in the reversible fan, the air output and efficiency are only slightly lower, ie in particular that the air output and efficiency are high in the reversible system. In other operating modes, such as synchronized speed of the two partial impellers or efficiency-optimized speed ratios, even higher efficiencies and / or air outputs of the reversible overall fan can be achieved, whereby the efficiency of the overall fan can also be higher than the efficiency of one of the non-reversible partial fans.

List of reference symbols

1

fan

2

Fan impeller, total fan impeller

2a, 2b

Fan impeller

3a, 3b

Partial fan impeller

4th

engine

5

Inlet nozzle

6, 6a, 6b

Blades of an impeller

7th

Hub of an impeller

8th

Foot of a wing 6

9

Hub half of a hub 7

10

screw

11

Leading edge of a wing 6

12th

Trailing edge of a wing 6

13th

Connecting element of two hubs

14th

Hub-motor shaft connecting element

15th

Mounting for wing foot in hub 7

16

Device for fastening the housing 17

17th

Housing, entire housing of the fan

18a, 18b

Part housing of the fan

19th

Rotor of a motor

20th

Stator of a motor

21

electric wire

22nd

camp

23

Connection area between partial housings

24, 24a, 24b

Engine support device, guide wheel

25th

Support strut, guide vane

26th

Electronics room

27

Electronics cover

Claims (15)

Fan with at least one electric motor and aerodynamically effective components or elements, which comprise at least one impeller equipped with blades, with some of the aerodynamically effective components or elements due to their arrangement or orientation mainly in one conveying direction and another part of the aerodynamically effective ones for the reversibility of the conveying direction Components or elements can mainly be assigned to the other opposite conveying direction due to its arrangement or orientation. Fan according to claim 1, characterized in that the direction of rotation of the impeller or impellers can be reversed to reverse the conveying direction, with some of the aerodynamically effective components or elements due to their arrangement or orientation mainly in one direction of rotation and another part of the aerodynamically effective components or elements can mainly be assigned to the other opposite direction of rotation due to their arrangement or orientation. Fan according to Claim 2, characterized in that, in order to change the direction of rotation of the impeller or impellers, the direction of rotation of the motor or motors can be changed and / or motors responsible for one conveying direction can be switched on and off. Fan according to claim 2 or 3, characterized in that at least one impeller is equipped with blades optimized or arranged for the respective direction of rotation, the impeller or impellers with respect to the blade angle and / or to the impeller or impeller design can be optimized to the respective requirements for the respective assignable conveying direction. Fan according to one of claims 1 to 4, characterized in that the blades are arranged in pairs for one and the other conveying direction, in particular in pairs in each case by 180 ° with respect to a transverse axis, are preferably arranged rotated to a transverse axis orthogonal to the fan or motor axis. Fan according to one of Claims 1 to 5, characterized in that the angular position of the blades which can be assigned to the two conveying directions are identical or, depending on requirements, are set or adjustable differently. Fan according to one of claims 1 to 6, characterized in that at least two identical, at least similar or different impellers equipped with blades are provided, which are arranged one behind the other in the conveying direction and are non-rotatably connected to one another, the impellers by 180 with respect to a transverse axis or radial axis ° are rotated, whereby the impellers can be identical or, depending on requirements, different in terms of the blade angle and / or the impeller design. Fan according to one of claims 1 to 7, characterized in that two partial fan units are arranged one behind the other in the conveying direction, each of which comprises at least one impeller and possibly a housing or housing part as well as a motor or a common motor, the partial fan units with regard to their arrangement or Orientation can each be assigned to a conveying direction. Fan according to Claim 8, characterized in that preferably the impeller of the partial fan unit connected downstream in the conveying direction also rotates without a drive. Fan according to Claim 8 or 9, characterized in that the impeller connected downstream in the conveying direction is used to measure the volume flow. Fan according to one of Claims 8 to 10, characterized in that the impeller connected downstream in the conveying direction is operated as a generator for at least one operating range. Fan according to Claim 11, characterized in that the energy / power obtained as a generator is transferred electrically to the respective other motor, for example via an intermediate circuit, or mechanically, for example via a mechanical coupling or a shaft connection. Fan according to Claim 11 or 12, characterized in that the energy / power obtained as a generator is at least partially fed into the power grid. Fan according to one of Claims 8 to 13, characterized in that the speed of the impeller connected downstream in the conveying direction is monitored and used to control the sub-fan unit connected in each case in the conveying direction, the control possibly avoiding excessive vibrations and possibly the bearing life and service life or fatigue strength should favor. Fan according to one of claims 8 to 14, characterized in that at least one of the partial fan units comprises one or more support devices which can be designed, for example, as a guide device.

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