Abstract:
A device ( 10 ) for suspending gas channel elements, in particular for suspending guide blades or guide blade segments or gas channel segments, on a housing of a gas turbines is provided. The device comprises first plate-shaped elements ( 11, 12, 13, 14 ) and second plate-shaped elements ( 15, 16, 17 ), whereby the first plate-shaped elements ( 11, 12, 13, 14 ) and the second plate-shaped elements ( 15, 16, 17 ) are connected together by web-like elements ( 18 ) which extend in an essentially perpendicular manner in relation to the first and second elements and form a meandering or crenelated profile.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a device for suspending gas channel elements. 
     BACKGROUND 
     Gas channel elements, such as guide blades, guide blade segments, gas channel plates, or gas channel plate segments, are used among other things for forming a flow channel or gas channel of the gas turbine and must be suspended or mounted on the housing of the gas turbine. The first ends of the gas channel elements, e.g., the guide blades, protrude into the gas channel and their second ends are attached to the housing of the gas turbine. The gas channel elements are attached to the housing via a device for suspending gas channel elements which may also be referred to as a suspension device or a suspension element. 
     The gas channel elements, in particular the guide blades protruding into the gas channel, are subjected to extreme thermal stress, in particular in the area of the high-pressure turbine of the gas turbine. The gas channel elements are thus heated to high temperatures in particular in the area of the high-pressure turbine. In contrast, the housing is relatively cold and thus has a lower temperature. The suspension elements for suspending gas channel elements on a housing of a gas turbine are therefore in contact with the relatively hot gas channel elements and with the relatively cold housing. Therefore, a high temperature gradient is formed in the suspension devices or suspension elements, thereby exposing them to extreme thermal stresses. This may result in stress cracks within the suspension devices and consequently in a reduced service life. 
     The devices for suspending gas channel elements on a housing of a gas turbine known from the related art can only inadequately absorb the above-mentioned thermal stresses due to the differences between the relatively cold housing of the gas turbine and the relatively hot gas channel elements. The devices for suspending gas channel elements thus have a limited service life. 
     SUMMARY OF THE INVENTION 
     Based on this, an object of the present invention is to create a novel device for suspending gas channel elements. 
     In accordance with an embodiment of the present invention, a device for suspending gas channel elements on a housing of a gas turbine comprises a plurality of first plate-shaped elements connected to a plurality of second plate-shaped elements. The first plate-shaped elements and the second plate-shaped elements are connected to one another only by web-like elements and each web-like element extends approximately perpendicularly to the first and second plate shaped elements to which it is connected and forms a crenelated profile extending in a circumferential direction of the housing. Preferably, a length of the web-like element in the circumferential direction being greater, by a multiple greater than one, than a width of the web-like element in an axial direction. 
     By using the device according to the present invention for suspending gas channel elements it is achieved that the thermal expansion of the gas channel elements is not transferred to the device according to the present invention in such a way that the service life of the device according to the present invention is reduced. Moreover, the shape of the device according to the present invention is selected in such a way that different degrees of expansion within the device according to the present invention in the contact area of the relatively cold housing and in the contact area of the relatively hot gas channel are absorbed by avoiding a rigid ring structure in such a way that stresses due to the different thermal expansions are negligible and the service life of the device according to the present invention is thus not affected. 
     According to an advantageous refinement of the present invention, a second plate-shaped element is positioned between two adjacent first plate-shaped elements in such a way that the opposite ends of the second plate-shaped element are connected to each of the two adjacent first plate-shaped elements via a web-like element. The web-like elements advantageously extend over the entire width of the first plate-shaped elements and/or the second plate-shaped elements. 
     According to an advantageous refinement of the present invention, boreholes are introduced into the first plate-shaped elements into which bolt-like fastening elements are insertable on the housing side for the connection to the housing of the gas turbine. For the connection to the gas channel element or each gas channel element, the second plate-shaped elements are insertable into recesses assigned to projections of the gas channel elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention are explained in greater detail based on the drawing, without being restricted thereto. 
         FIG. 1  shows a perspective view of a device for suspending gas channel elements according to the present invention; 
         FIG. 2  shows the device for suspending gas channel elements according to the present invention together with a gas channel element and a housing of a gas turbine, and 
         FIG. 3  shows a cross section through the system according to  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a device  10  according to the present invention for suspending gas channel elements on a housing of a gas turbine in a simple perspective view. Device  10  according to the present invention shown in  FIG. 1  has multiple first plate-shaped elements  11 ,  12 ,  13 , and  14  and multiple second plate-shaped elements  15 ,  16 , and  17 . First plate-shaped elements  11 ,  12 ,  13 , and  14  are connected to second plate-shaped elements  15 ,  16 , and  17  via web-like elements  18  extending approximately perpendicularly to same and form a meandering or crenelated profile. 
     A device according to an embodiment of the present invention for suspending gas channel elements has first plate-shaped elements and second plate-shaped elements, the first plate-shaped elements and the second plate-shaped elements being connected to one another via web-like elements extending approximately perpendicularly to same and forming a meandering or crenelated profile. 
     As is apparent in  FIG. 1 , second plate-shaped elements  15 ,  16 , and  17  are positioned between two adjacent first plate-shaped elements  11  and  12 ,  12  and  13 , as well as  13  and  14 , respectively. Each of these second plate-shaped elements  15 , or  16 , or  17  is connected at its opposite ends to one of the two adjacent first plate-shaped elements  11  and  12 ,  12  and  13 , as well as  13  and  14  via a web-like element  18 . As mentioned above, web-like elements  18  extend approximately perpendicularly to first plate-shaped elements  11  through  14  and second plate-shaped elements  15  through  17 . Web-like elements  18  extend over the entire width of first plate-shaped elements  11 ,  12 ,  13 ,  14  as well as over the entire width of second plate-shaped elements  15 ,  16 , and  17  in the connecting area with same. 
     The above described meandering or crenelated profile or contour of device  10  according to the present invention for suspending gas channel elements on a housing of a gas turbine ensures to the highest possible degree the reduction of stresses due to temperature gradients which occur in the case of thermal differences between the relatively hot gas channel elements and the relatively cold housing. Web-like elements  18 , which extend essentially at right angles or perpendicularly to plate-shaped elements  11  through  17 , are deformed due to thermal stresses only in the elastic range so that no service life-reducing material stress occurs. 
     It should be noted in this connection that it is advantageous to design the web-like elements, which are used for connecting first plate-shaped elements  11  through  14  to second plate-shaped elements  15  through  17 , to be as long as possible. This makes it possible to reduce the thermal stresses in device  10  according to the present invention particularly well. 
     Device  10  according to the present invention for suspending gas channel elements shown in  FIG. 1  has four plate-shaped elements  11  through  14 , three second plate-shaped elements  15  through  17 , and six web-like elements  18  for connecting second plate-shaped elements  15  through  17  to first plate-shaped elements  11  through  14 . When device  10  shown in  FIG. 1  is used in a gas turbine, multiple such devices  10  are joined to form a ring-shaped suspension structure to fasten all required gas channel elements to the housing along the circumference of the housing. According to  FIG. 1 , device  10  is thus designed as a ring segment. In contrast to the shown exemplary embodiment, it is also possible to design device  10  according to the present invention directly in the form of a ring. 
     As mentioned repeatedly, device  10  according to the present invention is used for suspending gas channel elements on a housing of a gas turbine. First plate-shaped elements  11  through  14  are used for connecting device  10  according to the present invention to housing  19  of the gas turbine. This is particularly apparent in  FIG. 2 . For connecting device  10  according to the present invention to housing  19  of the gas turbine via first plate-shaped elements  11  through  14 , boreholes  20  are introduced into first plate-shaped elements  11  through  14 . Boreholes  20  are best seen in  FIG. 1 . Bolt-shaped fastening elements  21  assigned to housing  19  engage in boreholes  20  for mounting with housing  19 . The meandering or crenelated contour of device  10  according to the present invention enables in this connection a very direct flow of force in the direction of arrow  22  (see  FIG. 3  in particular) starting from fastening elements  21  into device  10  according to the present invention since the fastening elements are situated in the direct flow of force between housing  19  and device  10  according to the present invention. Therefore, bending stresses are reduced to a minimum within the scope of the present invention. 
     Second plate-shaped elements  15  through  17 , which are situated offset opposite first plate-shaped elements  11  through  14 , are used for connecting the device according to the present invention to at least one gas channel element.  FIGS. 2 and 3  show a profiled support as such a gas channel element  23 , multiple such profiled supports in a turbine-bearing intermediate housing, also referred to as a turbine center frame, forming a bearing star for bearing shafts and rotors of the gas turbine. It should be pointed out here that the device according to the present invention may of course be used for suspending other gas channel elements, e.g., gas channel plate segments or guide blade segments, or also individual guide blades and individual gas channel plates. 
     As is apparent in  FIGS. 2 and 3  in particular, second plate-shaped elements  15  through  17  are used for the connection with gas channel element  23 . For this purpose, second plate-shaped elements  15  through  17  are insertable into recesses assigned to gas channel element  23 . In the shown exemplary embodiment, the two outer second plate-shaped elements  15  and  17  are used for the connection with gas channel element  23 . Projections  25 , which essentially extend outward in the radial direction, are assigned to an outer shroud band  24  of gas channel element  23 , one recess  26  being introduced into each projection  25 , the two outer plate-shaped elements  15  and  17  being insertable into the recesses. Gas channel element  23  is thus hooked into second plate-shaped elements  15  and  17  via recesses  26 . 
     In the shown exemplary embodiment, a guide pin  27 , which extends inward in the radial direction, is assigned to the middle second plate-shaped element  16 . Guide pin  27  engages in a corresponding recess  28  which is assigned to outer shroud band  24  of gas channel element  23 . Circumferential adjustment or circumferential centering of the gas channel element  23  is possible by guide pin  27  engaging in recess  28 . As is apparent in  FIG. 2  in this connection, the middle second plate-shaped element  16  is radially offset inward with respect to outer second plate-shaped elements  15  and  17 . 
     The above connection of gas channel element  23  with device  10  according to the present invention has the advantage that fastening elements protruding into the gas channel, such as screws in which great thermal stresses are then induced, may be avoided. In addition, the above described fastening method makes a relative motion between gas channel element  23  and device  10  according to the present invention possible. This relative motion causes improved reduction in thermal circumferential stresses and may take on the function of a floating bearing in the flow direction. 
     The above described device according to the present invention may be manufactured in one piece as a casting using simple means. The one-piece design of device  10  according to the present invention makes simple assembly of same possible.