Abstract:
A compressor, in particular, of a turbomachine The compressor comprises at least one blade ring and at least two ring segments, wherein the blade ring has at least two equally large ring segments. The compressor also comprises blades, which are arranged in the ring segments of the blade ring in such a way that a first number of blades is arranged in a first ring segment and a second number of blades is arranged in a second ring segment. The first number of blades is not equal to the second number of blades.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of the German patent application No. 10 2013 224 081.3 filed on Nov. 26, 2013, the entire disclosures of which are incorporated herein by way of reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to a compressor, for example, a fluid kinetic machine as described in the document DE 103 26 533 A1. 
         [0003]    First, such a compressor can be installed in combination with a combustion chamber and a turbine in a gas turbine, for example. Second, however, such a compressor can also be constructed as an independent module to be driven by an independent machine. 
         [0004]    In rotation of a bladed rotor with respect to a stationary stator, in particular a stationary housing or stationary blades, the stationary modules are excited to vibration by the movement of the rotor and the blades of the rotor are excited to vibration by the stationary modules. However, vibrations within the fluid kinetic machine, in particular a gas turbine and/or a jet engine, are a disadvantage because gas turbine modules are exposed to a higher load and thus to greater wear as a result of vibrations. Resonant vibrations, in particular, must be prevented. 
         [0005]    With the state of the art referenced above, the blades of a rotor have different spacings (blade pitch spacing). Unfortunately this approach is not suitable for repeating stages, because with this approach the resonant vibration between the steps is not taken into account. Repeating steps are compressor steps whose blades are identical and are arranged one after the other. In the technical world we speak of “clocked” stages. The different stages typically have the same pitch. In general, this means that the excitation arrangement of the oncoming flow and the outgoing flow of each repeating stage are identical. 
       SUMMARY OF THE INVENTION 
       [0006]    Thus an object of the present invention is to provide an approach which will avoid blade vibration, in particular in repeating stages of a compressor. 
         [0007]    This object is achieved by the features of claim  1 . 
         [0008]    The invention relates to a compressor, in particular of a fluid kinetic machine This compressor includes at least one blade ring, at least two ring segments, wherein the blade ring is divided into at least two ring segments, in particular, of the same size. Furthermore, the compressor comprises blades which are arranged in ring segments of the blade ring in such a way that a first number of blades are arranged in a first ring segment and a second number of blades are arranged in a second ring segment. The first number of blades is not equal to the second number of blades. Segments in blade rings may preferably occur in pairs. 
         [0009]    In another advantageous embodiment of the invention, the compressor comprises at least two stages, each stage having a rotor blade ring and a guide vane ring. 
         [0010]    In another advantageous embodiment of the invention, each guide vane ring is divided into at least two ring segments, in particular, of the same size. 
         [0011]    In another advantageous embodiment of the invention, each rotor blade ring is divided into at least four ring segments, in particular, of the same size. 
         [0012]    This is advantageous, in particular, because this creates a phase shift in the flow at the circumference so that an excitation of vibration of the guide vane as well as the rotor blades is reduced. 
         [0013]    In an advantageous embodiment of the invention, the distances between the blades of the first ring segment are the same and/or the distances between the blades of the second ring segment are the same. This is advantageous, in particular, because in the case of two-piece housings (split cases), in particular, with industrial gas turbines or compressors in process engineering plants, the first ring segment is arranged in the top half of the housing and the second ring segment is arranged in the bottom half of the housing. Guide vane ring segments, in particular, may thus be provided with different numbers of blades on a grating. For example, the upper ring segment will have X blades and the lower ring segment will have X+a blades, where the following relationships hold: a≠0 and X&gt;2. 
         [0014]    In another advantageous embodiment of the invention, the compressor comprises an additional blade ring having at least two additional ring segments, wherein the additional blade ring is divided into at least two additional ring segments, in particular of the same size, which in turn have additional blades. It should be pointed out that the blade rings may be both guide vane rings and rotor blade rings. Furthermore, the additional blade ring for rotor blades may be divided into at least four additional ring segments, in particular, of the same size. 
         [0015]    In another advantageous embodiment of the invention, the second additional ring segment has the first number of additional blades and/or the first additional ring segment has the second number of additional blades. This is advantageous, in particular, because at least one additional phase shift of the flow on the circumference can be introduced beyond the mesh. 
         [0016]    In another advantageous embodiment of the invention, the angle positioning of the first ring segment on the blade ring is identical to the angle positioning of the second additional ring segment on the additional blade ring. 
         [0017]    This is advantageous, in particular, because at least one additional phase shift of the flow can be introduced at the circumference over the compressor stages. 
         [0018]    In another advantageous embodiment of the invention, the angular positioning of the second ring segment on the blade ring is identical to the angular positioning of the first additional ring segment on the additional blade ring. It is particularly advantageous that at least one additional phase shift of the flow on the circumference can be introduced over the compressor stages without having to alter the number of blades of the corresponding mesh. 
         [0019]    In another advantageous embodiment of the invention, the two blade rings are twist-secured relative to one another. If the blade rings are rotor blade rings, then these are connected to one another by means of the main shaft of the fluid kinetic machine If the blade rings are guide vane rings, then they are connected to one another via the housing of the fluid kinetic machine. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    Preferred exemplary embodiments of the invention are described in greater detail below on the basis of the schematic drawings, in which: 
           [0021]      FIG. 1 : shows a longitudinal section through a compressor. 
           [0022]      FIG. 2 : shows a developed view of two stages of the above compressor. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]      FIG. 1  shows a longitudinal section through a compressor  2 . A housing  4  runs horizontally in the upper area and the main shaft  6  runs in the lower area. The first guide vane ring  8  and the second guide vane ring  10  are mounted on the housing  4 , but only one of the guide vanes is visible, running vertically here in  FIG. 1 . The first rotor blade ring  12  and the second rotor blade ring  14  are mounted on the main shaft  6  but only one of the rotor blades is visible here, running vertically in the figure. The first rotor blade ring  12  and the first guide vane ring  8  form a compressor stage  16 , for example, the first compressor stage here. The second rotor blade ring  14  and the second guide vane ring  10  form another compressor stage  18 , here, for example, the second compressor stage. It should be pointed out that the compressor stages need not necessarily be arranged directly side by side so that at least one other compressor stage may be present between the compressor stages  16  and  18  shown here. 
         [0024]      FIG. 2  shows a top view of the development of the two compressor stages  16 ,  18  from  FIG. 1 . The lateral surface of all four laid rings  8  through  14  is shown in a horizontal developed view. The first row shows the first rotor blade ring  12 , the second row shows the first guide vane ring  8 , the third row shows the second rotor blade ring  14  and the fourth row shows the second guide vane ring  10 . 
         [0025]    The first rotor blade ring  12  here is preferably divided into two or four ring segments  20  and  22  of the same size. The direction of rotation of the rotor blade ring  12  is indicated with an arrow at the far left. These may, in fact, be separable components so that one ring segment preferably covers a circumference of 90° or 180°. The first ring segment  20  of the rotor blade ring  12  comprises a first number X+a of rotor blades  23 , and the second ring segment  22  of the rotor blade ring  12  comprises a second number X of rotor blades  23  wherein the following relationships hold in  FIG. 2 : X=2 and a=1. It is only necessary for the following conditions to be met: X&gt;2 and a&gt;0. The rotor blades  23  in the first ring segment  20  have a first pitch t 1 . The rotor blades  23  and the second ring segment  22  have a second pitch t 2 , wherein the second pitch t 2  is greater than the first pitch t 1  as can be seen in  FIG. 2 . It should be pointed out that the term “pitch” is understood to refer to the distance between two neighboring blades. In  FIG. 2  this refers to the distance t 1 , t 2 ; u 1 , u 2  in the circumferential direction between the two front edges of the blades. Ring segments with the same pitch should preferably be arranged opposite one another for the sake of balance. 
         [0026]    For the second rotor blade ring  14  the same thing applies as for the first rotor blade ring  12 . The second rotor blade ring  14  here is also preferably subdivided into two ring segments  24  and  26  of the same size. There may, in fact, be two separable components so that one ring segment preferably covers a circumference of 180°. The first ring segment  24  of the rotor blade ring  14  comprises the second number X of rotor blades  28 , and the second ring segment  26  of the rotor blade ring  14  comprises the first number X+a of rotor blades  24 , wherein the following holds in  FIG. 2 : X=2 and a=1. Only the following conditions must be met: X&gt;2 and a&gt;0. The rotor blades  28  in the first ring segment  24  have the second pitch t 2 . The rotor blades  28  in the second ring segment  26  have the first pitch t 1 , wherein as shown in  FIG. 2 , the second pitch t 2  is greater than the first pitch t 1 . The rotor blade ring  12  of the first compressor stage  16  is thus designed as the opposite of the rotor blade ring  14  of the next compressor stage  18  (the second here). It is now conceivable that the rotor blade ring of the third compressor stage (not shown) has the same rotor blade distribution of the first rotor blade ring  12 . Thus, the rotor blade rings of the uneven compressor stages may have the blade configuration of the first rotor blade ring  12  and the rotor blade rings of the even compressor stages may have the blade configuration of the second rotor blade ring  14 . Since the rotor blade rings of a high-pressure compressor are connected to the main shaft  6 , for example, their positions relative to one another do not change so that these rotor blade rings always have a configuration that is rotated by 180° from the first stage. 
         [0027]    The first guide vane ring  8  here is preferably subdivided into two ring segments  30  and  32  of the same size. Since the guide vane ring  8  does not rotate, there is no arrow at the left such as that shown with the rotor blade rings  12  and  14 . In fact, these may be two separable components so that one ring segment preferably covers a circumference of 180°. The first ring segment  30  of the guide vane ring  8  includes a first number Y+b of guide vanes  34 , and the second ring segment  32  of the guide vane ring  8  includes a second number Y of guide vanes  34 , wherein the following holds in  FIG. 2 : Y=2 and b=1. It is only necessary to satisfy the following conditions: Y≧2 and b&gt;0. The guide vanes  34  in the first ring segment  30  have a first pitch u 1 . The guide vanes  34  in the second ring segment  32  have a second pitch u 2 , wherein, as  FIG. 2  shows, the second pitch u 2  is greater than the first pitch u 1 . 
         [0028]    The second guide vane ring  10  here is also preferably subdivided into two ring segments  36  and  38  of the same size. These may, in fact, be two separable components so that one ring segment preferably covers a circumference of 180°. The first ring segment  36  of the second guide vane ring  10  includes the second number Y of guide vanes  40 , and the second ring segment  38  of the second guide vane ring  10  comprises the first number Y+b of guide vanes  40 , wherein the following holds in  FIG. 2 : Y=2 and b=1. Only the following conditions must be met: Y&gt;2 and b&gt;0. The guide vanes  40  in the first ring segment  36  have the second pitch u 2 . The guide vanes  40  in the second ring segment  38  have the first pitch u 1 , wherein as  FIG. 2  shows the second pitch u 2  is greater than the first pitch u 1 . The guide vane ring  8  of the first compressor stage  16  is thus designed the opposite of the guide vane ring  10  of the next compressor stage  18  (the second here). It is now conceivable for the guide vane ring of the third compressor stage (not shown) to have the same guide vane distribution of the first guide vane ring  8 . Thus, the guide vane rings of the odd-numbered compressor stages may have the blade configuration of the first guide vane ring  8  and the guide vane rings of the even-numbered compressor stages may have the blade configuration of the second guide vane ring  10 . Since the guide vane rings of a high-pressure compressor, for example, are connected to the housing  4 , there is no change in their position relative to one another so that these guide vane rings always have a configuration that is rotated by 90° from one stage to the next stage. 
         [0029]    Due to this blade configuration, vibrations can be prevented and thus the corresponding component may be designed to be thinner so that weight can be saved on such a compressor according to the invention in the fluid kinetic machine. 
         [0030]    As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art. 
       LIST OF REFERENCE NUMERALS 
       [0000]    
       
           2  compressor 
           4  housing 
           6  main shaft 
           8  first guide vane ring 
           10  second guide vane ring 
           12  first rotor blade ring 
           14  second rotor blade ring 
           16  first compressor stage 
           18  second compressor stage 
           20  first ring segment of  12   
           22  second ring segment of  12   
           23  blades of  12   
           24  first ring segment of  14   
           26  second ring segment of  14   
           28  blades of  14   
           30  first ring segment of  8   
           32  second ring segment of  8   
           34  blades of  8   
           36  first ring segment of  10   
           38  second ring segment of  10   
           40  blade of  10   
         X+a; Y+b a first number of blades 
         X; Y a second number of blades