Abstract:
A fan holder for a fan includes a frame that has an opening through which a gaseous medium flows during operation. The opening forms an accommodating region that is designed to accommodate various replaceable inserts, in particular a filter insert and a flap device, and has at least one retaining device for fastening the particular insert.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a fan holder for a fan, in particular of a switch cabinet, and to a ventilating device, in particular for a switch cabinet, and to a set comprising a fan holder, at least one flap device and at least one filter mat. 
         [0003]    2. Discussion of the Related Art 
         [0004]    The prior art discloses fan devices comprising a fan holder and a fan, which is retained by the fan holder. In the case of such fan devices, cold air is taken in via a filter mat comparatively far down in the switch cabinet and is forced out via a (coarse) exit filter mat comparatively high up. This is intended to avoid the introduction of dust and to generate a positive pressure in the cabinet. The fans known in the prior art are considered to be comparatively ineffective and, in particular, not to be particularly variable. 
         [0005]    It is therefore an object of the invention to propose a fan holder, a fan device and a set comprising a fan holder, wherein effective cooling can take place, and wherein it is possible to cater in particular in a variable manner for the user&#39;s requirements. 
       SUMMARY OF THE INVENTION 
       [0006]    The object is achieved by a fan holder for a fan, in particular of a switch cabinet, said fan holder having a frame with an opening, through which a gaseous medium flows during operation, wherein the opening forms an accommodating region, which is adapted to accommodate different, interchangeable inserts, in particular a filter insert and a flap device, and has at least one retaining means for fixing the respective insert. 
         [0007]    A core idea of the invention is to provide a fan holder in which it is possible to introduce both a flap device and a filter insert. For this purpose, a corresponding retaining device is provided on the frame or in the accommodating region. This means that the user can insert a flap device into the fan holder. Overall, it is possible to cater in a variable manner for the user&#39;s particular requirements. It has been found here that the main task of a fan device for switch cabinets is that of cooling the switch cabinet by air circulation. The intention is to avoid the introduction of dust in the process. The latter, however, is not the main task. It has also been found that more effective cooling can be carried out if a filter device is installed in the upper third of a switch cabinet. It has therefore been considered that the air, rather than being expelled from a switch cabinet via a filter mat (which would result in reduced air throughput), should be expelled via a flap device, which results in improved air flow. Prior-art fan devices have always provided a filter mat, in order to achieve corresponding protection against dust. By virtue of an outlet filter being installed in the upper region of the switch cabinet (for example in the upper half, in particular in the upper third, of the switch cabinet), an air stream is distributed uniformly onto the inlet filter, which may be arranged in particular in the lower half, in particular in a lower third, of the switch cabinet. This renders an inlet-filter mat comparatively durable and less polluting. Since the fan holder can accommodate both a flap device and a filter insert, the user of the fan holder can make a choice. The user can therefore choose between improved air circulation or improved dust avoidance. 
         [0008]    It is particularly preferred to have a fan holder in which the opening is delimited laterally by retaining surfaces, which retain the respective insert in the frame. In particular, the accommodating region comprises a retaining device, in particular at least one elastic element or at least one latching nose, which subjects the respective insert to a retaining force during operation. This means that a user can readily change over the insert and adapt it to different applications. For example, in order to fix the inserts in the accommodating region, it is possible to arrange an elastic element in each of the corners of the accommodating region, said elastic elements connecting the retaining surfaces. 
         [0009]    It is particularly advantageous, moreover, to provide a separable, in particular pivotably mounted, cover, via which the fan holder, in particular the accommodating region thereof, can be closed in the outward direction. The frame of the fan holder forms preferably an, in particular all-round, step, on which the cover can be positioned. 
         [0010]    The aforementioned object is also achieved by a set. The set comprises a fan holder according to the invention, a flap device and a filter insert, wherein the flap device and filter insert can be accommodated in the same accommodating region of the fan holder. 
         [0011]    The aforementioned object is also achieved by a ventilating device. The ventilating device serves, in particular, for use in or on a switch cabinet and comprises a fan holder according to the invention and also a fan. It is particularly advantageous if the fan is connected to the fan holder via a fan funnel. The fan holder advantageously ensures homogenization of the air stream. 
         [0012]    The aforementioned object is also achieved by a flap device. The flap device is provided for use with a fan holder according to the invention and comprises a flap frame, which can be inserted into the accommodating region of the fan holder, and holds at least one, in particular more than one, flap, said flaps, for the purpose of deflecting the flow, at least partially covering over the flap frame. The flaps are advantageously connected in a releasable manner to the flap frame. Furthermore, the fan holder is arranged preferably in the upper half of the switch cabinet, in particular in an upper third of the switch cabinet. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The invention is explained in more detail hereinbelow with reference to the drawing, in which: 
           [0014]      FIG. 1  shows a schematic exploded illustration of a ventilating device; 
           [0015]      FIG. 2  shows a schematic exploded illustration of a fan holder; 
           [0016]      FIG. 3  shows a schematic exploded illustration of the fan holder with a flap device according to the invention; 
           [0017]      FIG. 4  shows a cross section through an assembled set comprising a fan holder with flap insert, a fan and a cover; and 
           [0018]      FIG. 5  shows a schematic illustration of a switch cabinet having two ventilating devices. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    The following description uses the same designations for like, and like acting, parts.  FIG. 1  shows a ventilating device comprising a fan holder  10  having a cover  11 , which is closed off in the direction of an outer side  12  by a front lattice  13 . In the direction of an inner side  14 , the fan holder  10  is followed by a fan funnel  15 . The fan funnel  15 , in turn, is followed by a fan  16 . The fan  16  may be designed, in particular, in the form of an axial fan. 
         [0020]    In one use example, the ventilating device is connected to a switch cabinet (not shown). The ventilating device here is inserted into an aperture in a switch-cabinet wall and fixed there by a suitable fastening means, which is located in particular on the fan holder  10 . The ventilating device thus establishes a connection between the interior of the switch cabinet and the outer region thereof. Depending on the direction of rotation of the fan  16  located in the switch cabinet, air can be taken into the switch cabinet, or expelled therefrom, by the ventilating device. 
         [0021]    The fan holder  10  has a frame  26  and an accommodating region  28 , which is formed by an opening  27  in the fan holder  10 . The fan holder  10  also has an all-round inner step  19 , which is formed on the frame  26  and against which the cover  11  can butt in the closed state of the accommodating region  28 . 
         [0022]    Different inserts can be inserted into the accommodating region  28  of the fan holder  10  and fixed there by suitable retaining means. In particular, the opening  27  is delimited by retaining surfaces  29 , which retain the respective insert in the frame. It is further possible to provide specific retaining devices, for example latching, clip-action, rubber or magnetic elements, in order to fix a respective insert in the accommodating region  28 . In that embodiment of the invention which is shown in  FIG. 1 , an insert is retained by elastic elements  30 , which subject the insert to a retaining force. The elastic elements  30  are arranged in corners  31  of the accommodating region  28  and, in this way, connect the retaining surfaces  29  to one another. 
         [0023]    The accommodating region  28  can be closed by means of the cover  11 . In an open state, the cover  11  allows access to the accommodating region  28 . The cover  11  is fastened in a removable, preferably pivotable, manner on the fan holder  10 , in particular on an edge of the frame  26  which, when the ventilating device is in the installed state, is directed toward the floor. The cover  11  can be arrested in a closed position on the fan holder  10  by suitable snap-fit and/or latching means or the like. The maximum opening angle of the cover  11  in relation to the frame  26  is preferably predetermined by suitable delimiting elements. This makes it possible overall for the inserts to be changed over particularly straightforwardly if required. 
         [0024]    As illustrated in  FIGS. 2 and 3 , a flap device  21  may be installed, in the form of an interchangeable insert, in the accommodating region  28 . The flap device  21  comprises a flap frame  32  and flap-retaining crosspieces  22  as well as a multiplicity of flaps (lamellae)  23  (of which, to give a better view, only five are illustrated). The flaps (lamellae)  23  are mounted, in particular clipped, in a pivotable manner on the retaining crosspieces  22  and can be pivoted by air flowing out from the direction of the arrow  33 . 
         [0025]    It is conceivable also to provide an active pivoting device (for example an electromotive one). In the installed state, the flap frame  32  has an outer surface butting preferably against the retaining surfaces  29 . 
         [0026]    As an alternative to the flap device  21 , the interchangeable insert used may also be a filter insert  24  (see  FIG. 2 ), which is inserted into the accommodating region  28 . The filter insert may be, for example, a filter mat or similar suitable filter element. Whereas, the main purpose of the filter insert is to filter out particles, such as dust or the like, the flap device  21  serves to realize an enhanced air throughput without any filtering of the air flowing through the flap device  21 . An end user of the ventilating device, consequently, can decide himself whether to equip the fan holder with a flap device, for optimized air circulation/cooling in a switch cabinet, or with a filter insert, for optimized dust avoidance. 
         [0027]    The front lattice  13  may also be in the form of a netting or similar air-permeable material. Furthermore, for cleaning or changeover purposes for example, it may be designed such that it can be released from the cover  11 . Without the front lattice  13 , the cover  11  forms a rectangular (all-round) frame (having two rectilinearly running edges and two curved edges, the rectilinearly running edges being located opposite one another, as are the curved edges). Similarly, a main body  25  of the fan holder  10  also forms an all-round (rectangular) frame. Two mutually opposite sides of the main body  25  are of rectilinear design; the other mutually opposite sides are curved. In the installed state of the cover  11 , the curved sides are in alignment with the curved sides of the main body  25  of the fan holder  10 . This achieves a homogeneous unit. 
         [0028]      FIG. 4 , in addition, shows a cross section through an assembled set comprising a fan holder  10  with a flap insert  21 , a fan  16  and a cover  11 . It is clear from  FIG. 4  that the cover  11 , and the front lattice  13  accommodated therein, is arranged in front of the fan holder  10 , as seen in the air-exit direction  39 . This arrangement with the cover  11  and the front lattice  13  in front of the fan holder advantageously prevents foreign bodies, in particular water, entering into the ventilating device through one or more open flaps  23 . 
         [0029]    In particular the front lattice  13  in the embodiment shown in  FIG. 4  is designed in the form of a diffuser, which prevents liquid, e.g. when it rains, from entering into the interior of the ventilating device and, in particular, into the fan. This is because, when the fan  16  is at a standstill, there is a risk of the flaps  23  opening as a result of a, for example, draft-induced negative pressure or of a mechanical blockage, wherein, consequently, the switch-cabinet interior is open, and dirt, water, etc., could penetrate, when the fan  16  is at a standstill. The diffuser is configured such that it conforms to relative standards, in particular in respect of the safety requirements, and has an ideal flow shape for the exit of air. As  FIG. 4  shows, the front lattice  13 , for this purpose, has a plurality of through-slots  39 , of, in particular, oval or elliptical cross section. The longitudinal axis L of the through-slots  39  is oriented in relation to the flaps  23  such that it is oriented essentially parallel to the flaps  23  in the (fully) open state (see line L′ in  FIG. 4 ). This minimizes the flow resistance of the through-slots  39 . 
         [0030]    The front lattice  13  can be opened from the outside preferably only with the use of a screwdriver and can be closed from the inside by the catch being locked. This provides for straightforward protection against vandalism. Furthermore, the front lattice  13  is mounted preferably in a rotatable manner in the frame of the cover  11 , in order to allow for servicing to be carried out. 
         [0031]      FIG. 5 , in addition, shows, schematically, a case where the invention is used with a switch cabinet  34  and two ventilating devices  35  and  36 . Whereas the lower ventilating device  35 , in the vicinity of the floor, engages through the switch-cabinet wall  37  in a lower third of the latter, the second ventilating device  36  is arranged in an upper third of the switch-cabinet wall  37 . Of course, the two ventilating devices need not be arranged in the same switch-cabinet wall. 
         [0032]    Provision may advantageously be made for the first, lower ventilating device  35  to form an inlet ventilating device, which has a filter insert, e.g. a filter mat, in the accommodating region  28  and in the case of which a fan takes air into the switch cabinet  34  in order to generate a positive pressure. The positive pressure in the switch cabinet is intended to prevent particles, in particular dust or the like, from entering into the switch cabinet through doors, cable ducts or other openings. 
         [0033]    Whereas the prior art, thus far, also equipped the upper ventilating device  36  with a filter insert, in order to reduce further the entrance of particles into the switch cabinet, the ventilating device  36  may advantageously comprise a flap device  21 , which is shown in  FIGS. 2 and 3 , in the accommodating region  28 . The upper ventilating device  36  serves as an outlet ventilating device and, consequently, the fan has a direction of rotation which causes air to be expelled from the switch cabinet  34 . The air stream which is established in the switch cabinet  34  by way of the lower and upper ventilating devices  35 ,  36  is indicated in  FIG. 5  by the arrow  38 . In contrast to a filter mat, the flap device  21  does not reduce the air throughput, and this makes it possible for the switch cabinet  34  to be cooled effectively in the upper region. The result is improved air flow in the switch cabinet, which also has a positive effect on the filter insert in the lower ventilating device  35 , since the amount of air taken in is smaller and therefore the air is filtered not just be way of that surface area of the filter insert which corresponds to the impeller of the fan  16 , but by way of the entire surface area of the filter. As a result, the air taken in is thus distributed more uniformly overall over the entry filter insert. The filter insert is thus more durable and contamination is reduced. Furthermore, the flap device  21  advantageously prevents undesired foreign bodies, in particular dust, water or the like, from penetrating into the switch cabinet when the fan is at a standstill. This advantageous effect is achieved in that, when the fan is at a standstill, the flaps  23  are closed and thus close off the fan, and the switch-cabinet interior, against foreign bodies. The pivotable mounting of the flaps means that the latter are thus retained in the closed state, preferably by the force of gravity or by an electric motor, when the fan  16  has been switched off. It is only when the fan is in the switched-on state that the flaps  23  are shifted into an open position by the resulting air stream. 
         [0034]    The flexible insert options and the modular construction with the aid of the fan holder according to the invention means that both systems can be readily realized by the present invention: on the one hand, it is possible to achieve optimized dust avoidance by it also being possible for the upper fan holder  10  to be readily provided, if required, with a filter insert  24 . Furthermore, for optimized air circulation, and thus for optimized cooling at the uppermost location, it is possible, as an alternative, to insert a flap insert  21  into the fan holder, in order to achieve the abovedescribed optimized-cooling function. 
         [0035]    The modularity of the system according to the invention provides for a particularly high level of flexibility, allowing a user to adapt the fan holder individually to existing requirements and, if necessary, to change over the inserts in the accommodating region  28  in a particularly straightforward manner. 
       LIST OF DESIGNATIONS 
       [0000]    
       
           10  Fan holder 
           11  Cover 
           12  Outer side 
           13  Front lattice 
           14  Inner side 
           15  Fan funnel 
           16  Fan 
           19  Step 
           21  Flap device 
           22  Retaining crosspieces 
           23  Flaps 
           24  Filter insert 
           25  Main body 
           26  Frame 
           27  Opening 
           28  Accommodating region 
           29  Retaining surfaces 
           30  Elastic element 
           31  Corners 
           32  Flap frame 
           33  Arrow 
           34  Switch cabinet 
           35  Ventilating device 
           36  Ventilating device 
           37  Switch-cabinet wall 
           38  Arrow 
           39  Air-exit direction 
           40  Through-slots 
         L Longitudinal axis