EP2559905A2 - Engine mount for ventilators, preferably axial ventilators, and method for producing a ventilation grill of such an engine mount - Google Patents

Abstract

The motor suspension has an air grille (1) with radially extending braces (3) and grille rings (2) that are positioned coaxially to each other and are connected to each other by the radially extending braces. The number of the braces and diameter of the braces is varied with regard to reduction of acoustic noises and/or natural resonances of the motor suspension for adjustment of the vibration behavior of the fan. Each brace have a radial outer end (9) that is fastened to the outer support ring (10). An independent claim is included for method involves for manufacturing ventilation grille for motor suspension.

Description

The invention relates to a motor suspension for fans, preferably axial fans, according to the preamble of claim 1 and a method for producing a ventilation grille of such a motor suspension according to the preamble of claim 19th

There are engine suspensions are known, the ventilation grille coaxially with each other having grid rings which are interconnected by radially extending struts ( DE 10 2009 025 025 A . DE 23 45 539 A . DE 101 11 397 A . DE 197 53 373 A ). The radially inner ends of the struts are either formed as fasteners for connection to the motor or connected to a mounting plate which is connected to the fan. The radially outer end of the struts has retaining elements ( DE 101 11 397 A ), which serve to receive connection means with the fan. The ventilation grids have straight sections in axial section, wherein the radially inner and outer regions are inclined relative to each other and connect at an obtuse angle to a straight central region. Such ventilation grille can be produced only consuming, since for each of these grid areas a separate welding device and thus a separate welding process is needed.

Since noise can occur during operation of the fan, it is known to produce the radially extending struts from flat profiles, which are placed obliquely to the fan longitudinal axis in accordance with a mean swirl component ( DE 10 2009 025 025 A ). It is also known that between the Form radially outward and radially inner end of the support struts sections out of the plane of the flat profile, so that their associated with the lattice rings edges are maintained as a straight line. However, this makes the manufacture and construction of the ventilation grille very complex.

To avoid flow-induced noise, it is further known ( DE 197 53 373 A ), the ventilation grille in the manner of an air-stator with blade-like, over a certain axial air guide length extending substantially substantially radially arranged guide webs form. The guide webs are arranged in at least two concentric rows of circles, wherein the number of guide ribs in the outer circle row is greater than in the adjacent inner row of circles. Such a design of a ventilation grille is structurally very complex, which makes the production of the ventilation grille more expensive.

It is finally known ( DE 101 11 397 A ), a comb-like damping means aufzustecken on the coaxial grid rings.

The invention has the object of providing the generic engine mount and the generic method in such a way that in a structurally simple and cost-effective manner optimum noise and vibration reduction is achieved during operation of the fan.

This object is achieved in the generic engine suspension according to the invention with the characterizing features of claim 1 and the generic method according to the invention with the characterizing features of claim 19.

In the engine mount according to the invention, the number and / or the diameter (cross-section) of the struts with respect to a reduction of the acoustic noise and / or the self-resonance of the engine mount is varied to adapt to the vibration behavior of the fan. By varying the strut number and / or the strut diameter, it is thus possible in a simple manner to tune the engine mount to the particular application so that the acoustic noises occurring during operation are minimized and / or the occurrence of self-resonance of the engine mount is avoided.

In one embodiment, to reduce noise during operation of the fan, the number of struts, preferably made of metal, is chosen to be different than the number of blades of the fan. Thus, the ventilation grille can be optimally tuned to the respective fan used in terms of noise reduction.

This tuning is particularly easy to perform when the struts are attached with their radially outer end to a Außentragring. It is therefore easily possible to easily attach the desired number of struts on the ventilation grille.

An inexpensive and simple training results when the Außentragring has a cylindrical outer side to which the radially outer ends of the struts are attached.

Advantageously, the Außentragring consists of flat material. It is advantageously formed from a strip which is bent into a cylinder. In this way, the Außentragring can be very easily produced in any required diameter.

The Außentragring may in another embodiment consist of a flat material, which lies in a radial plane of the ventilation grille. This also ensures a simple production of Aussentragringes. On the flat Außentragring the ends of the struts can be easily attached.

The outer support ring does not have to be formed from a flat material. It can also be formed from at least one, but preferably from a plurality of grid rings. With the grid rings as Aussentragring is also a simple and inexpensive production of the ventilation grille and thus the engine mount possible. The outer rings forming grid rings can be in a radial plane next to each other with distance. But it is also possible that grid rings with the same diameter are arranged one above the other, so that they form a quasi-cylindrical Außentragring.

The radially outer ends of the struts are bent in an advantageous manner. Then the ends can be very easily attached to the outer support ring.

A secure attachment of the radially outer strut ends results when the radially outer ends of the struts do not project beyond the Außentragring. In an advantageous embodiment, the length of the strut ends is shorter than the axial height of the Außentragringes. As a result, the strut ends can be attached over their entire length on Außentragring.

Advantageously, the radially inner ends of the struts are attached to a raised Innentragring. The struts then connect the outer support ring with the inner support ring. The inner support ring allows the ventilation grille to be connected to the fan easily and independently of its mounting pitch. Since the outer support ring and the inner support ring are formed circumferentially and the inner support ring thereby erected, the struts can be mounted at any suitable point of the ventilation grille and connected to the Außentragring and the inner support ring.

The engine mount is advantageously designed so that when using the Außentragringes the engine mount can be performed individually and independently of the mounting pitch of the customer interface. The customer interface is used to attach the engine mount or the outer support ring to a wall ring that contains the nozzle for the fan. The customer interface can, for example, by drilling be formed in the edge region of the nozzle of the wall ring, through which screws or the like are plugged, with which the Außentragring, which is placed on the nozzle, can be connected to the nozzle. In such a case, the screwing of Außentragringes done radially with the nozzle.

In the advantageous use of the Innentragringes the engine mount can be performed individually and independently of the mounting pitch of the fan. The radially inner ends of the struts are in this case advantageously attached to the erected edge of the Innentragringes, while the interface for connection to the fan is outside of this raised edge.

The engine mount according to claim 11 is characterized in that the ventilation grid has an arched shape in axial section. This makes it possible to weld the ventilation grille in a single device in a single operation. The ventilation grille and thus the engine mount can be very inexpensive and easy to produce.

Advantageously, the struts are preferably made of metal over their length arc-shaped convexly curved. The grid rings, which are interconnected by these struts, thus form in outline a curved ventilation grille, which, seen in axial section, no longer has straight areas, but extends curved over its radial width.

Advantageously, some of the struts project radially inwardly and / or outwardly beyond the grid rings.

The protruding ends of these struts are advantageously provided with connections with which the ventilation grille can be attached, for example, to a wall ring and the fan.

Some of the ventilation grille struts may have a length less than the radius of the ventilation grille. Here, these shorter struts can have the same length, but also different lengths. By appropriate choice of the length and / or the cross section of these struts, the engine mount can be tuned to the vibration behavior of the fan so that the operating noise is minimized and / or no self-resonance of the engine mount occur.

Since the longer struts for connecting the ventilation grille serve, for example, to a wall ring and to the fan, they advantageously have a larger cross-section than the short struts.

The method according to the invention is carried out in such a way that the number and / or the cross-section of the struts is varied in order to reduce the acoustic noise and / or the displacement of the self-resonances of the engine mount, with regard to the reduction of the acoustic noises and / or the displacement of the self-resonances of the engine mount , This makes it very easy to adapt the engine mounting to the vibration behavior of the fan.

It is also possible, for example, to choose the number of struts so that it is not equal to the number of blades of the fan. If the fan has four wings, for example, then the ventilation grille has a different number of struts. Depending on the size and / or installation location of the fan, it is very easy to determine the optimum number of struts. In this way, not only the acoustics, especially the rotational sound of the fan can be reduced, but also a possible natural vibration frequency of the engine mount can be counteracted. Due to the selected number of struts, it is possible to tune the components of the engine mount according to the invention to each other so that the noise and / or the natural resonances of the engine mount are minimized.

The number of struts does not necessarily have to be different from the number of blades of the fan. Rather, it is crucial that the number of struts and / or their diameter is selected so that the desired and described adaptation of the engine mount is tuned to the vibration behavior of the fan.

A simple procedure results when the radially outer ends of the struts are fastened to an outer support ring. The Außentragring allows the individual variation of the number of struts, especially regardless of the mounting pitch of the customer interface.

A simple and inexpensive production is possible if the radially outer ends of the struts are fastened to the outside of the Außentragringes.

Further features of the invention will become apparent from the other claims, the description and the drawings.

Fig. 1

in perspektivischer Darstellung eine erfindungsgemäße Motoraufhängung,

Fig. 2

eine Draufsicht auf die Motoraufhängung gemäß Fig. 1,

Fig. 3

in vergrößerter Darstellung einen Axialschnitt durch die erfindungsgemäße Motoraufhängung,

Fig. 4

in perspektivischer Darstellung die mit einem Ventilator verbundene Motoraufhängung gemäß den Fig. 1 bis 3,

Fig. 5

in perspektivischer Darstellung eine zweite Ausführungsform einer erfindungsgemäßen Motoraufhängung,

Fig. 6

in perspektivischer Darstellung die Motoraufhängung gemäß Fig. 5, die an einem Wandring befestigt ist,

Fig. 7

in perspektivischer Darstellung eine dritte Ausführungsform einer erfindungsgemäßen Motoraufhängung,

Fig. 8

in vergrößerter Darstellung einen Axialschnitt durch die Motoraufhängung gemäß Fig. 7,

Fig. 9

in perspektivischer Darstellung eine vierte Ausführungsform einer erfindungsgemäßen Motoraufhängung,

Fig. 10

in vergrößerter Darstellung einen Axialschnitt durch die Motoraufhängung gemäß Fig. 9,

Fig. 11

in perspektivischer Darstellung eine fünfte Ausführungsform einer erfindungsgemäßen Motoraufhängung,

Fig. 12

in vergrößerter Darstellung einen Axialschnitt durch die Motoraufhängung gemäß Fig. 11,

Fig. 13

in perspektivischer Darstellung eine sechste Ausführungsform einer erfindungsgemäßen Motoraufhängung,

Fig. 14

eine Unteransicht der Motoraufhängung gemäß Fig. 13,

Fig. 15

in vergrößerter Darstellung einen Axialschnitt durch die Motoraufhängung gemäß Fig. 13,

Fig. 16

in perspektivischer Darstellung die Motoraufhängung gemäß Fig. 13, die an einem Wandring befestigt ist,

Fig. 17

im Axialschnitt eine Vorrichtung zum Schweißen eines Lüftungsgitters der erfindungsgemäßen Motoraufhängung,

Fig. 18

in einer Darstellung entsprechend Fig. 17 eine bekannte Vorrichtung zum Schweißen eines Lüftungsgitters nach dem Stand der Technik,

Fig. 19

in einem Diagramm den Wirkungsgrad eines Motors mit der erfindungsgemäßen Motoraufhängung in Abhängigkeit von der Drehzahl des Ventilators.

The invention will be explained in more detail with reference to some illustrated in the drawings embodiments. Show it

Fig. 1

in a perspective view of an engine mount according to the invention,

Fig. 2

a plan view of the engine mount according to Fig. 1 .

Fig. 3

in an enlarged view an axial section through the engine mount according to the invention,

Fig. 4

in a perspective view of the associated with a fan engine mount according to the Fig. 1 to 3 .

Fig. 5

in a perspective view of a second embodiment of an engine mount according to the invention,

Fig. 6

in a perspective view of the engine mount according to Fig. 5 which is attached to a wall ring,

Fig. 7

in a perspective view a third embodiment of an engine mount according to the invention,

Fig. 8

in an enlarged view an axial section through the engine mount according to Fig. 7 .

Fig. 9

in a perspective view of a fourth embodiment of an engine mount according to the invention,

Fig. 10

in an enlarged view an axial section through the engine mount according to Fig. 9 .

Fig. 11

a perspective view of a fifth embodiment of an engine mount according to the invention,

Fig. 12

in an enlarged view an axial section through the engine mount according to Fig. 11 .

Fig. 13

in a perspective view of a sixth embodiment of an engine mount according to the invention,

Fig. 14

a bottom view of the engine mount according to Fig. 13 .

Fig. 15

in an enlarged view an axial section through the engine mount according to Fig. 13 .

Fig. 16

in a perspective view of the engine mount according to Fig. 13 which is attached to a wall ring,

Fig. 17

in axial section a device for welding a ventilation grille of the engine mount according to the invention,

Fig. 18

in a representation accordingly Fig. 17 a known device for welding a ventilation grille according to the prior art,

Fig. 19

in a diagram, the efficiency of a motor with the engine mount according to the invention as a function of the speed of the fan.

The engine mount is for a fan 11 ( Fig. 4 ), preferably an axial fan, provided and has a ventilation grille 1, which has coaxially extending grid rings 2. They advantageously have an equal distance from each other, in plan view Fig. 2 seen. The grating rings 2 advantageously have a circular cross section ( Fig. 3 ) and are advantageously made of metal. Depending on the application, the grid rings 2 may also have a different cross-section from a circular shape.

In the illustrated preferred embodiment, all grid rings 2 of the ventilation grille 1 have the same cross-sectional area. But it is also possible that the individual grid rings have a different cross section depending on the location within the ventilation grille 1.

The grid rings 2 are connected to each other by radially extending struts 3. They are also advantageously made of metal. You can also consist of wires with circular cross section, but also be designed as a profile-shaped struts. The course of the struts 3 over their length determines the shape of the ventilation grille 1. The struts 3 are curved arcuately convex over their length, whereby the ventilation grille 1 a has arched shape. The struts 3 can be curved evenly over their length. It is advantageous, however, if the struts 3 in the radially inner region of the ventilation grille 1 have a smaller radius of curvature than in the radially outer region. The ventilation grille therefore drops more in the radially inner region than in the radially outer region (FIG. Fig. 1 and 3 ).

As the Fig. 1 and 3 show, the struts 3 are mounted on the outside of the grid rings 2, that is, on the side facing away from the fan side of the grid rings. Are the struts and the grid rings made of metal, then they are welded together at the crossing points.

The struts 3 give the ventilation grille 1 a high stability and strength.

The radially inner ends 4 ( Fig. 3 ) of the struts 3 are angled in the direction of the fan 11 and fixed to an inner support ring 5. He has a flat, lying in a radial plane of the ventilation grille 1 ring part 6, the edge 7 is directed obliquely upward. The strut ends 4 are attached to the outside of the Innentragringrandes 7. The ring member 6 has distributed over its circumference arranged openings 8. On the ring part 6 of the Innentragringes 5, the fan 11 is fixed in a known manner.

The radially outer ends 9 of the struts 3 are attached to the outside of a Außentragringes 10. It is coaxial with the axis of the ventilation grille 11. As out Fig. 3 shows, the ring member 6 is axially offset in the direction of the fan 11 to the outer support ring 10, seen in the axial direction, greater distance from the fan 11 than the ring member 6 of the Innentragringes 5. The inner support ring 5 and the Außentragring 10 are advantageously made of metal. The struts 3 can then, if they are preferably made of metal, easy to attach by a welding process.

In order to reduce the acoustics, in particular the rotary sound of the fan 11, a grid concept with a variable and / or asymmetrical number of struts 3 is used. Thus, for example, by changing the number of struts 3 and / or by changing the strut cross section, the overall system of engine mount and fan 11 can be detuned easily and inexpensively so that the vibration values are low, as will be described in more detail below. By way of example, the number of struts 3 can be selected not equal to the number of blades 12 of the fan 11, regardless of the interfaces to the outer support ring 10 and the inner support ring 5. The number of struts 3 depending on the number of fan blades 12 of the fan 11 used simply can vary, the Außentragring 10 is used to attach the struts 3 with its radially outer end 9, which is angled so that it can be fastened flat on the outside of Außentragringes 10. The outer support ring 10 is preferably made of a flat material, which is preferably bent to an upstanding ring. On Außentragring 10, the different number of struts 3 can be easily attached, so that the engine mount in a simple manner and independently of the interfaces to outer and inner support ring on the fan 11 used and its number of blades can be adjusted to minimize the noise.

The number of struts 3 can also be chosen so that a possible natural vibration frequency of the engine mount is avoided.

It is due to the described training, the possibility of the components of the engine mount, that is, the ventilation grille 1 with the struts 3 and the Außentragring 10 so coordinated that not only reduces the rotational sound or even avoided, but also the occurrence of vibrations of the engine mount due is prevented by resonances.

The curved ventilation grille 1 also improves the efficiency of the engine. Fig. 19 shows the course of the efficiency as a function of the speed of the fan or the volume flow q _v . The solid line applies to the curved ventilation grille and the dashed line for the conventional ventilation grille, which consists of flat in axial section, lying at an angle grid areas. The motors with the curved ventilation grilles have a higher efficiency than the conventional motors.

Thus, the ends 9 of the struts 3 can be easily attached to the outer support ring 10, at least its outer side is a smooth cylindrical surface. The strut ends 9 are shorter than the height of the Außentragringes 10. It is in principle possible to attach the strut ends 9 by means of fastening means, such as screws, bolts and the like, on the outside of the Außentragringes 10. Such attachment may also be provided in addition to a welded connection between the strut ends 9 and the Außentragring 10. The length of the strut ends 9 may differ from the illustrated embodiment also equal to the height or even greater than the height of the Außentragringes 10. The strut ends 9 are in any case attached to the Außentragring 10 that they are not, based on the illustration in accordance with Fig. 3 , projecting down over the Außentragring 10.

The grid rings 2 have such a distance from each other that they do not obstruct the passage of air or only slightly. In addition, the distance is selected so that users can not reach by hand through the ventilation grille 1 and can come into contact with the impeller of the fan 11. The connection of the Außentragringes 10 can be made radially or axially in any division, based on the interface (nozzle). The connection of the Innentragringes 5 can be made without consideration of the interface to the fan 11. This will be explained in more detail below. The ventilation grille 1 with the Außentragring 10 is placed on the free edge of a nozzle 13 ( Fig. 4 ) projecting from a plate-shaped wall ring 14. In the region of the nozzle 13, the impeller of the fan 11 is arranged with the wings 12 in a known manner. The Außentragring 10 is fixed with radially extending screws 15 at the free edge of the nozzle 13. The nozzle 13 forms the customer interface. The engine mount can be carried out individually and independently of the mounting pitch of the customer interface due to the described training. The angular distance of the screws 15 over the circumference of the Außentragringes 10 is specified by the customer. The struts 3 can be provided independently of this customer-provided distribution of the screws 15 so that the noise is minimized and reliably avoided a resonance point in the operating range of the engine mount.

Since the radially outer ends 9 of the struts 3 are mounted on the outside of Außentragringes 10, the ventilation grille 1 can be properly with the Außentragring 10 touch down on the free edge of the nozzle 13.

The embodiment according to Fig. 5 is substantially the same design as the embodiment according to the Fig. 1 to 4 , The only difference is that the outer support ring 10 is screwed axially on the wall ring 14 ( Fig. 6 ). For this purpose, arranged on the outer support ring 10 distributed over the circumference, transversely projecting tabs 16 are provided, which rest in the installed position on the wall ring 14 and are connected to it via the screws 15. The radially projecting from Außentragring 10 tabs 16 are in the area below the free ends of the strut ends 9. This makes it possible even with such an axial connection of the engine mount to the wall ring 14, perform the engine suspension individually and independently of the pitch of the tabs 16. The number of struts 3 can thus in turn be chosen without regard to the formation of the customer's interface so that the ventilation grille 1 is optimized in terms of noise reduction and the avoidance of natural resonances of the engine mount.

The described embodiment of the inner support ring 5 makes it possible to carry out the engine suspension individually and independently of the fastening pitch of the fan 11. The openings 8 in the ring part 6 of the inner support ring 5 may have any distribution that does not affect the attachment of the radially inner ends 4 of the struts 3. These strut ends 4 are located in both described embodiments on the outside of the raised edge 7 of the Innentragringes. 5

In the embodiment of the Fig. 7 and 8th the Außentragring 10 is exemplified by two coaxial grid rings 2 'formed, which are adjacent to each other at a distance and on which the angled ends 9 of the struts 3 are attached. In contrast to the previous embodiments, the strut ends 9 extend approximately horizontally, in the illustration according to Fig. 8 seen. The strut ends 9 are advantageously welded to the grid rings 2 '. Depending on the length of the strut ends 9, the Außentragring 10 can consist of only one or more than two lattice rings 2 '.

So that the ventilation grille 1, for example, on a wall ring 14 ( Fig. 6 ), the outer grid ring 2 'has connections 16' distributed uniformly over its circumference, which are formed by radially outwardly deformed parts of the grid ring 2 '. The outer grid ring 2 'is formed outwardly such that the terminal 16' has two mutually parallel wire sections 31, 32 which extend approximately radially outward and arcuate into one another and arcuate in the grid ring 2 'transition. Between the wire sections 31, 32 discs 22 are fixed, through which the fastening screws 15 (FIG. Fig. 6 ) protrude, with which the ventilation grille 1 is mounted on the wall ring 14.

Incidentally, the ventilation grille according to the Fig. 7 and 8th the same design as in the previous embodiments.

The described embodiment according to the Fig. 7 and 8th shows that the Außentragring 10 does not necessarily have to be formed from a flat material, but that for fastening the outer strut ends 9 and grid rings 2 'can be used.

In the embodiment of the Fig. 9 and 10 the Außentragring 10 is again formed by a flat material, but in contrast to the embodiments of the Fig. 1 to 6 not upright, but lying is arranged. On the top of Außentragringes 10, the angled ends 9 of the struts 3 are attached. At the bottom of Außentragringes 10 distributed over the circumference arranged the tabs 16 are fixed, projecting radially outwardly beyond the Außentragring 10 and with which the ventilation grille 1 is fixed in the manner described on the wall ring 14. The strut ends 9 are slightly radially outwardly beyond the Außentragring 10 on which they are mounted in the manner described over its length. The length of the strut ends 9 can of course be equal to or less than the radial width of the Außentragringes 10th

Incidentally, the ventilation grille is the same as in the previous embodiments.

The ventilation grille 1 according to the Fig. 11 and 12 in turn has the superscript outer support ring 10, but in contrast to the embodiments according to the Fig. 1 to 6 is not formed from flat material, but from superimposed grid rings 2 '. In the illustrated embodiment, the Außentragring 10 is formed by four spaced apart superimposed, same outer diameter having grating rings 2 ', on the outside of the ends 9 of the struts 3 are attached. Depending on the embodiment, the outer support ring 10 may also consist of fewer or more lattice rings 2 '.

Over the circumference of this Außentragringes 10 evenly distributed connections 16 "are provided, of which in Fig. 11 only one connection is visible. The terminals 16 "are each formed by discs 22 which extend and are held between them with a lug between two adjacent lattice rings 2. Through the discs 22 protrude the fastening screws with which the ventilation grille 1 is attached to the fan as in the embodiment according to the Fig. 1 to 4 radially with respect to the ventilation grille 1.

Incidentally, the ventilation grille according to the Fig. 11 and 12 the same design as the embodiments according to the Fig. 1 to 6 ,

The ventilation grille concept, which is based on the embodiments according to the Fig. 1 to 12 has been explained, allows optimal noise optimization in use, characterized in that the number of struts 3, variable and / or can be designed in asymmetric distribution. The struts 3 can thus be optimally provided on the ventilation grille 1, that the noise is minimal when using the fan equipped with the ventilation grille. Thus, the vibration values can be achieved by changing the number of struts and / or by a corresponding arrangement on the ventilation grille in a simple manner. The detuning can also be optimally adjusted by a corresponding adaptation of the cross section of the struts and / or together with the number of struts. Experiments have shown that already by a change in cross section of the fastening struts 17, the vibration values can be significantly changed. If, in this case, the variation of the number of fixing struts 17 is also used, the vibration values can be excellently adapted to the respective application. In addition, this tuning of the vibration values is inexpensive to perform. By this measure, the weight of the ventilation grille 1 is not increased.

For engine mounting according to Fig. 13 an inner support ring and an outer support ring are not provided. The motor suspension has the grating rings 2 and the radially extending struts 3. They are in turn arc-shaped convexly curved along their length and extend from the radially outermost grating ring 2. In contrast to the previous embodiments, the struts 3 do not extend over the entire radial width of the ventilation grille 1, but end at a distance from the radially inner grating ring 2. For attachment of the ventilation grille 1 on the wall ring 14 (FIG. Fig. 16 ) and on the (not shown) fan fastening struts 17 are provided, which are convexly curved over its length and how the struts 3 are fixed on the side facing away from the fan side of the grating rings 2. The ends of the fastening struts 17 protrude radially over the outer and the inner grid ring 2. The fastening struts 17 are provided as in the previous embodiments by way of example at angular intervals of 90 ° on the ventilation grille 1.

Advantageously, the fastening struts 17 are formed by a hairpin-shaped curved grid bar, the two legs 18, 19 parallel to each other and at the radially outer end of the mounting strut 17 arcuately merge into one another.

The radially outer and inner ends 20, 21 of the mounting struts 17 are angled so that the ventilation grille 1 can be attached to the wall ring 14 and the fan in a suitable manner. On the ends 20, 21 each have a disc 22, 23 is fixed, through which protrude the fastening screws 15, with which the ventilation grille 1 is attached to the wall ring 14 and the fan.

The mounting plates 22, 23 at both ends of the fastening struts 17 are each at the same height. As Fig. 15 shows, however, the discs 23 are arranged at the radially inner end of the mounting struts 17 axially offset from the discs 22 at the radially outer end of the mounting struts. About the discs 22, the ventilation grille 1 is mounted on the wall ring 14. The radially inner discs 23 are spaced from the wall ring 14th

Due to the curved design, the ventilation grille 1 can be welded with a welding device in one operation. The device for welding has an outer ring, are connected to the upstanding radially extending struts. Of these aspirations is in Fig. 17 only one strut 24 is shown. It has a concavely curved end face 25, in which a small distance one behind the other recesses 26 are provided. They are only a short distance from each other. The struts of the device are arranged so that their recesses each lie on a circle. The grid rings 2 of the ventilation grille 1 to be produced are inserted into the recesses 26 of the struts 24. Depending on the design of the ventilation grille 1, for example, only in every second recess 26 or at irregular intervals, the grating rings 2 are inserted. With the help of the vertical struts 24 then the struts 3, 17 of the ventilation grille 1 can be welded to the grid rings 2. Since the struts 24 are arranged distributed uniformly over the circumference of the device and have relatively small distance from each other, the struts 3 can be connected to the lattice rings 2 in terms of the desired vibration behavior in the respectively required position and / or number.

With the device described, the ventilation grille 1 in the tub position can be welded in one operation, since the arcuate design of the ventilation grille 1 makes it unnecessary to use a separate welding device and a separate welding process for each area of the ventilation grille. The ventilation grille can therefore be very easily and inexpensively finished.

Fig. 18 shows a conventional apparatus for welding the ventilation grille according to the prior art. This ventilation grille 26 has in axial section a straight inner region 27, which connects at an obtuse angle to a straight central region 28. To him a radially outer portion 29 connects at right angles. In order to produce such a ventilation grille, three steps are required, which in the figures a) to c) of the Fig. 18 are shown. For each of the three grille regions 27 to 29, a separate device 30 to 32 adapted to these grating regions is required in each case. As a result, the production of this ventilation grille 26 is very complex and tedious.

The described curved shape of the ventilation grille 1 of the described embodiments, in contrast, allows a very simple and cost-effective production. Due to the arcuately curved cross-sectional configuration of the ventilation grille 1, this can be manufactured in one operation. All that is necessary for the ventilation grille 1 lattice rings 2 inserted into the corresponding recesses 26 of the struts 24 and then the required struts 3, 17 are welded to the inserted lattice rings 2.

Claims (16)

Motor suspension for fans, preferably axial fans, with a ventilation grille (1) with radially extending struts (3) interconnecting coaxial grid rings (2),
characterized in that for adapting the engine mount to the vibration behavior of the fan (11) the number and / or the diameter of the struts (3) is varied with a view to reducing the acoustic noise and / or the self-resonance of the engine mount. Motor suspension according to claim 1,
characterized in that the number of preferably consisting of metal struts (3) is not equal to the number of wings (12) of the fan (11) is executed. Motor suspension according to claim 1 or 2,
characterized in that the struts (3) are fixed with their radially outer end (9) on an outer support ring (10), which advantageously has a cylindrical outer side, on which the radially outer ends (9) of the struts (3) are attached. Engine mounting according to claim 3
characterized in that the outer support ring (10) consists of flat material and is a curved into a cylinder strip. Motor suspension according to claim 3,
characterized in that the outer support ring (10) consists of flat material which lies in a radial plane of the ventilation grille (1). Motor suspension according to claim 3,
characterized in that the outer support ring (10) of at least one, preferably a plurality of grid rings (2 ') is formed. Motor suspension according to one of claims 1 to 6,
characterized in that the struts (3) to form the preferably not on the Außentragring (10) projecting radially outer ends (9) are bent. Motor suspension according to one of claims 1 to 7,
characterized in that the struts (3) are fastened with their radially inner end (4) to a raised Innentragring (5). Motor suspension according to one of claims 1 to 8,
characterized in that when using the Außentragringes (10), the engine mount is individually and independently of the mounting pitch of the customer interface executable. Motor suspension according to one of claims 1 to 9,
characterized in that when using the Innentragringes (5) the motor suspension is individually and independently of the mounting pitch of the fan (11) executable. Motor suspension for fans, preferably for axial fans, with a ventilation grille (1) with radially extending struts (3, 17) interconnecting coaxial grid rings (2), in particular according to one of claims 1 to 10,
characterized in that the ventilation grille (1) in axial section a has arched shape. Motor suspension according to claim 11,
characterized in that the preferably made of metal struts (3, 17) are curved arcuately convex over their length. Engine mounting according to one of claims 1 to 12,
characterized in that some of the struts (17) protrude radially inwardly and / or outwardly beyond the grating rings (2) and that advantageously the projecting ends (20, 21) of the struts (17) are provided with terminals (22, 23) are. Motor suspension according to one of claims 1 to 13,
characterized in that some of the struts (3) have a length which is smaller than the radius of the ventilation grille (1), and that preferably the short struts (3) have a smaller cross-section than the longer struts (17). Method for producing a ventilation grille (1) of the engine mount according to one of claims 1 to 14, in which coaxial grid rings (2) and radially extending struts (3, 17) are connected to each other,
characterized in that the number and / or the cross-section of the struts (3, 17) is varied with regard to the reduction of the acoustic noise and / or the self-resonance of the engine mount. Method according to claim 15,
characterized in that the radially outer ends (9) of the struts (3) are fastened to an outer support ring (10).

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