Patent Publication Number: US-8529210-B2

Title: Air cycle machine compressor rotor

Description:
BACKGROUND 
     This disclosure generally relates to rotor for an air cycle machine. An air cycle machine may include a centrifugal compressor and a centrifugal turbine mounted for co-rotation on a shaft. The centrifugal compressor further compresses partially compressed air, such as bleed air received from a compressor of a gas turbine engine. The compressed air discharges to a downstream heat exchanger or other use before returning to the centrifugal turbine. The compressed air expands in the turbine to thereby drive the compressor. The air output from the turbine may be utilized as an air supply for a vehicle, such as the cabin of an aircraft. 
     SUMMARY 
     A disclosed compressor rotor for an air cycle machine (ACM) includes a plurality of blades that each includes a root, a tip, a first surface and a second surface. The first and second surfaces are defined as a set of X-coordinates, Y-coordinates and Z-coordinates set out in any of Table M-1 and M-2 or Table S1 and S-2 scaled by a desired factor. The X-coordinates being in the tangential direction, the Y-coordinates being in the axial direction and the Z-coordinates being in the radial direction. 
     The plurality of blades includes a plurality of main blades and a plurality of splitter blades disposed between the main blades. The main and splitter blades define a portion of a corresponding plurality of air passages through a compressor section of the disclosed ACM. 
     These and other features disclosed herein can be best understood from the following specification and drawings, the following of which is a brief description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of an example air cycle machine. 
         FIG. 2  is a perspective view of a front side of an example compressor rotor. 
         FIG. 3  is a perspective view of a back side of the example compressor rotor. 
         FIG. 4  is sectional view of a blade for the example compressor rotor. 
         FIG. 5  is plan view of the example compressor rotor. 
         FIG. 6  is a cross sectional view of the example compressor rotor. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an example air cycle machine  20  (“ACM”) that is incorporated into an air supply system  22  of a vehicle, such as an aircraft, helicopter, or land-based vehicle. The ACM  20  includes a compressor section  24 , a turbine section  26  and a fan section  28  that are generally disposed about a main shaft  30  that includes a tie rod. The compressor section  24  includes a compressor rotor  32 , the turbine section  26  includes a turbine rotor  34 , and the fan section  28  includes a fan rotor  36 . The compressor rotor  32 , turbine rotor  34 , and fan rotor  36  are secured on the main shaft  30  for co-rotation about an axis A. 
     The example compressor section  24  includes the compressor rotor  32 , a diffuser  38 , and compressor housing  40  that define a portion of a compressor air flow path. The diffuser  38  defines an inlet  42  into the ACM  20  to the compressor rotor  32 . The diffuser  38  further defines radial flow passages  44  that extend radially away from an outer periphery  46  of the compressor rotor  32 . 
     Referring to  FIGS. 2 and 3 , with continued reference to  FIG. 1 , the compressor rotor  32  includes a plurality of main blades  48  and a corresponding plurality of splitter blades  50 . The splitter blades  50  are disposed between the main blades  48  and do not extend the full length of the main blades  48 . The blades  48 ,  50  extend from a contoured surface  52  that transitions from an axially parallel portion  54  near a center of the compressor rotor  32  to a transverse surface  56  that is transverse to the axis A at the outer periphery  46  of the compressor rotor  32 . 
     Incoming airflow initially encounters the plurality of main blades  48  near the axial portion  54  of the compressor rotor  32  and is directed through passages defined between the plurality of main blades  48  and the plurality of splitter blades  50  to the outer periphery  46 . At the outer periphery  46  of the compressor rotor  32 , airflow is further directed radially outward through the passages  44  defined in the diffuser  38 . 
     The compressor rotor  32  includes a back side  58  that is not exposed to airflow and includes a surface substantially transverse to the axis of rotation A. A guide lug  60  extends axially from the back side  58  of the compressor rotor  32  and is received within a bore of a seal shaft  62  (Shown in  FIG. 1 ). The turbine rotor  34  is also secured to the seal shaft  62  such that both the turbine rotor  34  and the compressor rotor  32  rotate as a single unit. A fastening member  64  attached to an end of the main shaft  30  secures the compressor rotor  32  in place. 
     The main blades  48  and splitter blades  50  include a root  66 , a tip  68 , a leading edge  70 , a trailing edge  72 , a left surface  74  and a right surface  76  that are contoured to provide a desired airflow through the compressor section  24 . The main blades  48  and the splitter blades  50  extend from the contoured hub surface  52  that is defined between the main blades  48  and the splitter blades  50 . The contoured hub surface  52  along with the surfaces of the main blades  48  and the splitter blades  50  are defined utilizing computational fluid dynamics (CFD) analytical software and are tailored to providing the performance requirements for the specified ACM performance parameters. 
     The configuration of the left and right surfaces  74 , 76  of each main blade  48  and each splitter blade  50  changes in view of various dimensional parameters such as for example, curvature, thickness, twist, taper from the root tip, radius from the leading edge, radius from the trailing edge, and straightness of the leading and trailing edges from root to tip. Moreover, the example compressor rotor  32  may be directly scaled up or down to meet different ACM performance requirements. 
     Referring to  FIGS. 4 ,  5  and  6 , each of the plurality of main and splitter blades  48 ,  50  includes the left surface  74  and the right surface  76  that are shaped to provide a continuous contour from the leading edge  70  to the trailing edge  72 . In this disclosed example embodiment, Left and right is determined viewing the front ( FIG. 5 ) of the compressor rotor  32  including the main and splitter blades  48 ,  50 . 
     The shape of each of the main and splitter blades  48 ,  50  may be defined by a set of points such as in this example, Cartesian coordinates along a boundary of each of the surfaces. 
     Because a word description is difficult to construct that fully captures the three dimensional contours of each blade surface, one non-limiting dimensional embodiment is provided for the left and right blade surfaces in tables M1 and M2. 
     The Tables M1 and M2 are shown in a Cartesian coordinate system for X, Y and Z of each blade surface. The Cartesian coordinate system has orthogonally related X, Y and Z axes with the Z-axis extending generally in a radial direction relative to the axis of Rotation A and related with respect to Datum B. The X and Y coordinate values for determining the blade surface at each radial location are provided with respect to Z, wherein the Z coordinate values in the Tables disclosed represent a non-dimensionalized value equal to one (1) at Datum B. That is the disclosed, non-dimensionalized value Z in the Tables is provided as a ratio with respect to Datum B. It should be understood that a variety of reference Datums may alternatively or additionally be used. 
     By defining X and Y coordinate values at selected locations in the radial direction, i.e., in a Z direction with respect to Datum B, the left and right surfaces of the blades  48 ,  50  are ascertained. By connecting the X and Y values with smooth continuing arcs, each profile surface at the associated radial distance Z is defined. The surface profiles at the various radial locations between the radial distances Z are thereby ascertained by connecting adjacent surface profiles. Although the X, Y and Z axes are orientated in the disclosed fashion, it should be appreciated that the X, Y and Z axes may have any orientation provided that the axes are orthogonally oriented with respect to each other and one axis extends along a height of the blade. 
     The Table values are provided in inches and present actual airfoil profiles in ambient, non-operating or non-hot conditions for an uncoated airfoil, the coatings for which are described below. 
     
       
         
           
               
             
               
                 TABLES M1 
               
             
            
               
                   
               
               
                 Main Blade Right Surf 
               
            
           
           
               
               
               
            
               
                 X BSC 
                 Y BSC 
                 Ratio (Z BSC/-B-) 
               
               
                   
               
               
                 0.4281 
                 −0.1434 
                 1.7167 
               
               
                 0.4324 
                 −0.1684 
                 1.7154 
               
               
                 0.4542 
                 −0.2192 
                 1.6719 
               
               
                 0.4708 
                 −0.2452 
                 1.6302 
               
               
                 0.4931 
                 −0.2480 
                 1.5487 
               
               
                 0.5033 
                 −0.2019 
                 1.4626 
               
               
                 0.5094 
                 −0.1577 
                 1.3675 
               
               
                 0.5195 
                 −0.1667 
                 1.2771 
               
               
                 0.5383 
                 −0.2298 
                 1.2018 
               
               
                 0.5555 
                 −0.2894 
                 1.1711 
               
               
                 0.5613 
                 −0.3084 
                 1.0882 
               
               
                 0.5445 
                 −0.2783 
                 0.9892 
               
               
                 0.5336 
                 −0.2645 
                 0.9461 
               
               
                 0.5158 
                 −0.2689 
                 0.8422 
               
               
                 0.5073 
                 −0.3025 
                 0.7637 
               
               
                 0.5341 
                 −0.3727 
                 0.7565 
               
               
                 0.5690 
                 −0.4462 
                 0.7478 
               
               
                 0.5719 
                 −0.4863 
                 0.6811 
               
               
                 0.5253 
                 −0.4756 
                 0.5863 
               
               
                 0.4995 
                 −0.4731 
                 0.5376 
               
               
                 0.4691 
                 −0.4975 
                 0.4582 
               
               
                 0.4642 
                 −0.5745 
                 0.3719 
               
               
                 0.5321 
                 −0.6396 
                 0.3736 
               
               
                 0.6140 
                 −0.7178 
                 0.3316 
               
               
                 0.6269 
                 −0.7776 
                 0.2324 
               
               
                 0.5525 
                 −0.8002 
                 0.1579 
               
               
                 0.4736 
                 −0.8082 
                 0.1175 
               
               
                 0.4753 
                 −0.8575 
                 0.0567 
               
               
                 0.5162 
                 −0.8843 
                 0.0262 
               
               
                 0.5984 
                 −0.8893 
                 0.0262 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE M2 
               
             
            
               
                   
               
               
                 Main Blade Left Surf 
               
            
           
           
               
               
               
            
               
                 X BSC 
                 Y BSC 
                 Ratio (Z BSC/-B-) 
               
               
                   
               
               
                 0.3902 
                 −0.1185 
                 1.7323 
               
               
                 0.4004 
                 −0.1685 
                 1.7288 
               
               
                 0.4245 
                 −0.2193 
                 1.6832 
               
               
                 0.4424 
                 −0.2454 
                 1.6394 
               
               
                 0.4653 
                 −0.2486 
                 1.5541 
               
               
                 0.4739 
                 −0.2030 
                 1.4669 
               
               
                 0.4713 
                 −0.1556 
                 1.4185 
               
               
                 0.4771 
                 −0.1387 
                 1.3220 
               
               
                 0.4868 
                 −0.1697 
                 1.2798 
               
               
                 0.5038 
                 −0.2278 
                 1.2424 
               
               
                 0.5230 
                 −0.2885 
                 1.2043 
               
               
                 0.5292 
                 −0.3087 
                 1.1181 
               
               
                 0.5100 
                 −0.2789 
                 1.0229 
               
               
                 0.4870 
                 −0.2389 
                 0.9645 
               
               
                 0.4640 
                 −0.2596 
                 0.8285 
               
               
                 0.4858 
                 −0.3511 
                 0.7736 
               
               
                 0.5210 
                 −0.4282 
                 0.7581 
               
               
                 0.5445 
                 −0.4791 
                 0.7337 
               
               
                 0.5508 
                 −0.5236 
                 0.6677 
               
               
                 0.5287 
                 −0.5410 
                 0.5924 
               
               
                 0.4734 
                 −0.5613 
                 0.4759 
               
               
                 0.4093 
                 −0.5942 
                 0.3649 
               
               
                 0.4103 
                 −0.6516 
                 0.3130 
               
               
                 0.4888 
                 −0.7181 
                 0.3032 
               
               
                 0.5695 
                 −0.7522 
                 0.3104 
               
               
                 0.6220 
                 −0.8075 
                 0.2408 
               
               
                 0.5507 
                 −0.8487 
                 0.1421 
               
               
                 0.4703 
                 −0.8535 
                 0.1149 
               
               
                 0.4322 
                 −0.8928 
                 0.0495 
               
               
                 0.4736 
                 −0.9149 
                 0.0031 
               
               
                   
               
            
           
         
       
     
     Further, the contour of each of the first and second surfaces  48 ,  50  for the splitter blades is provided in tables S1 and S2 respectively. 
     
       
         
           
               
             
               
                 TABLES S1 
               
             
            
               
                   
               
               
                 Splitter Blade Right Surf 
               
            
           
           
               
               
               
            
               
                 X BSC 
                 Y BSC 
                 Ratio (Z BSC/-B-) 
               
               
                   
               
               
                 0.4279 
                 −0.1434 
                 1.7175 
               
               
                 0.4807 
                 −0.2463 
                 1.5954 
               
               
                 0.4969 
                 −0.2244 
                 1.5140 
               
               
                 0.5019 
                 −0.1540 
                 1.4181 
               
               
                 0.5142 
                 −0.1611 
                 1.3295 
               
               
                 0.5391 
                 −0.2465 
                 1.2659 
               
               
                 0.5571 
                 −0.2935 
                 1.1515 
               
               
                 0.5439 
                 −0.2517 
                 1.0898 
               
               
                 0.5272 
                 −0.2122 
                 1.0213 
               
               
                 0.5338 
                 −0.2603 
                 0.9525 
               
               
                 0.5430 
                 −0.2983 
                 0.9279 
               
               
                 0.5539 
                 −0.3377 
                 0.9045 
               
               
                 0.5677 
                 −0.4118 
                 0.8125 
               
               
                 0.5333 
                 −0.3798 
                 0.7428 
               
               
                 0.4951 
                 −0.3516 
                 0.6676 
               
               
                 0.4715 
                 −0.3492 
                 0.6107 
               
               
                 0.4655 
                 −0.3705 
                 0.5763 
               
               
                 0.5032 
                 −0.4368 
                 0.5878 
               
               
                 0.5504 
                 −0.5043 
                 0.5989 
               
               
                 0.5787 
                 −0.5486 
                 0.5892 
               
               
                 0.5499 
                 −0.5501 
                 0.5422 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE S2 
               
             
            
               
                   
               
               
                 Splitter Blade Left Surf 
               
            
           
           
               
               
               
            
               
                 X BSC 
                 Y BSC 
                 Ratio (Z BSC/-B-) 
               
               
                   
               
               
                 0.3904 
                 −0.1185 
                 1.7317 
               
               
                 0.4007 
                 −0.1685 
                 1.7276 
               
               
                 0.4253 
                 −0.2194 
                 1.6805 
               
               
                 0.4558 
                 −0.2470 
                 1.5912 
               
               
                 0.4649 
                 −0.1529 
                 1.4581 
               
               
                 0.4731 
                 −0.1348 
                 1.3619 
               
               
                 0.4942 
                 −0.1968 
                 1.2721 
               
               
                 0.5125 
                 −0.2567 
                 1.2293 
               
               
                 0.5246 
                 −0.2926 
                 1.1850 
               
               
                 0.5278 
                 −0.3030 
                 1.1404 
               
               
                 0.5101 
                 −0.2715 
                 1.0473 
               
               
                 0.4886 
                 −0.2300 
                 0.9930 
               
               
                 0.4715 
                 −0.2321 
                 0.8980 
               
               
                 0.4796 
                 −0.2760 
                 0.8641 
               
               
                 0.5067 
                 −0.3331 
                 0.8781 
               
               
                 0.5390 
                 −0.4120 
                 0.8496 
               
               
                 0.4784 
                 −0.4049 
                 0.6798 
               
               
                 0.4251 
                 −0.4181 
                 0.5540 
               
               
                 0.4462 
                 −0.4724 
                 0.5341 
               
               
                 0.5288 
                 −0.5372 
                 0.5965 
               
               
                 0.5597 
                 −0.5673 
                 0.6041 
               
               
                 0.5425 
                 −0.5788 
                 0.5251 
               
               
                   
               
            
           
         
       
     
     A tip contour of each of the main and splitter blades corresponds with a corresponding surface of the diffuser  38  ( FIG. 1 ) to define a portion of the airflow passages through the compressor section  24 . The contour of the tip surface  68  of both the main and splitter blades  48 ,  50  is defined relative to the hub contour surface  52 . In one non-limiting dimensional embodiment, the tip surface contour of each of the main and splitter blades  48 ,  50  are defined by a paired axial dimension K and radial dimensions J. 
     In one non-limiting dimensional embodiment, the hub contour surface  52  is defined by a set of paired axial dimensions M and radial dimensions L. The axial dimensions K and M are defined from the back side  58  of the compressor rotor  32  as specified by the datum surface E ( FIG. 6 ). The tip profile is disclosed in terms of the axial dimension K and the radial dimension J. The hub profile is disclosed in terms of the axial dimension M and the radial dimension L in the respective Tables. The J and L dimensions are defined in a generally radial direction relative to the axis of rotation A and as related to Datum B. The J and L coordinate values for determining the respective tip and hub profile at the associated axial coordinates K and M in the Tables are provided as a ratio with respect to Datum B. That is, the J and L coordinate values in the Tables represent a non-dimensionalized value equal to one (1) at Datum B. It should be understood that a variety of reference Datums may alternatively or additionally be used. The Table values are provided in inches, and represent actual blade profiles at ambient, non-operating or non-hot conditions for an uncoated airfoil, the coatings for which are described below. In this non-limiting dimensional embodiment, the set of paired dimensions K and J that define the tip surface  68  contour are defined in the table T-1. 
     
       
         
           
               
             
               
                 TABLE T-1 
               
             
            
               
                   
               
               
                 Tip 
               
            
           
           
               
               
               
            
               
                   
                 K 
                 Ratio (J Rad/-B-) 
               
               
                   
                   
               
               
                   
                 −1.0764 
                 0.9537 
               
               
                   
                 −0.9349 
                 0.9537 
               
               
                   
                 −0.9245 
                 0.9537 
               
               
                   
                 −0.9095 
                 0.9539 
               
               
                   
                 −0.8890 
                 0.9550 
               
               
                   
                 −0.7911 
                 0.9648 
               
               
                   
                 −0.7332 
                 0.9760 
               
               
                   
                 −0.6945 
                 0.9871 
               
               
                   
                 −0.6366 
                 1.0097 
               
               
                   
                 −0.5795 
                 1.0403 
               
               
                   
                 −0.4868 
                 1.1095 
               
               
                   
                 −0.4359 
                 1.1658 
               
               
                   
                 −0.3375 
                 1.2569 
               
               
                   
                 −0.3532 
                 1.3080 
               
               
                   
                 −0.3189 
                 1.4042 
               
               
                   
                 −0.3008 
                 1.4764 
               
               
                   
                 −0.2876 
                 1.5504 
               
               
                   
                 −0.2772 
                 1.6405 
               
               
                   
                 −0.2730 
                 1.7013 
               
               
                   
                 −0.2702 
                 1.7621 
               
               
                   
                 −0.2688 
                 1.8081 
               
               
                   
                 −0.2681 
                 1.8338 
               
               
                   
                 −0.2679 
                 1.8386 
               
               
                   
                 −0.2671 
                 1.8746 
               
               
                   
                   
               
            
           
         
       
     
     Moreover, in this non-limiting dimensional embodiment, the set of paired dimensions M and L that define the hub contour surface  52  are defined in table H-1. 
     
       
         
           
               
             
               
                 TABLE H-1 
               
             
            
               
                   
               
               
                 Hub 
               
            
           
           
               
               
               
            
               
                   
                 M 
                 Ratio (L Rad/-B-) 
               
               
                   
                   
               
               
                   
                 −1.1219 
                 0.4708 
               
               
                   
                 −1.0590 
                 0.4907 
               
               
                   
                 −0.9778 
                 0.4844 
               
               
                   
                 −0.9396 
                 0.4881 
               
               
                   
                 −0.9101 
                 0.4907 
               
               
                   
                 −0.8809 
                 0.4935 
               
               
                   
                 −0.7537 
                 0.5112 
               
               
                   
                 −0.6727 
                 0.5325 
               
               
                   
                 −0.5866 
                 0.5680 
               
               
                   
                 −0.4992 
                 0.6216 
               
               
                   
                 −0.4016 
                 0.7087 
               
               
                   
                 −0.2813 
                 0.8724 
               
               
                   
                 −0.2160 
                 0.9961 
               
               
                   
                 −0.1591 
                 1.1412 
               
               
                   
                 −0.1248 
                 1.2621 
               
               
                   
                 −0.0943 
                 1.4220 
               
               
                   
                 −0.0828 
                 1.5185 
               
               
                   
                 −0.0746 
                 1.6292 
               
               
                   
                 −0.0722 
                 1.6819 
               
               
                   
                 −0.0703 
                 1.7407 
               
               
                   
                 −0.0692 
                 1.7818 
               
               
                   
                 −0.0681 
                 1.8288 
               
               
                   
                 −0.0680 
                 1.8338 
               
               
                   
                 −0.0674 
                 1.8555 
               
               
                   
                 −0.0579 
                 2.2494 
               
               
                   
                   
               
            
           
         
       
     
     The contoured tip surface  68  and hub surface  52  are defined from the leading edge  70  to the trailing edge  72  by the disclosed dimensional embodiments defined in tables T-1 and H-1. The defined dimension can be directly scaled up or down to tailor compressor rotor configuration to ACM  20  specific requirements while remaining within the scope and contemplation of the disclosed dimensional embodiment. 
     As the blades heat up during operation, applied stresses and temperatures induced to the blades may inevitably cause some deformation of the airfoil shape, and hence there is some change or displacement in the table coordinate values. While it is not possible to measure the changes in the Table coordinate values in operation, it has been determined that the Table coordinate values plus the deformation in use, enables efficient, safe and smooth operation. 
     It is appreciated that the Table coordinate values may be scaled up or down geometrically in order to be introduced into other similar machine designs. It is therefore contemplated that a scaled version of the Table coordinate values set fourth may be obtained by multiplying or dividing each of the Table coordinates values by a predetermined constant n. It should be appreciated that the Table coordinate values could be considered a scaled profile with n set equal to 1, and greater or lesser dimensioned components are obtained by adjusting n to values greater or lesser than 1, respectively. 
     The Table values are computer-generated and shown to four decimal places. However, in view of manufacturing constraints, actual values useful for manufacture of the component are considered to be the values to determine the claimed profile. There are, for example, typical manufacturing tolerances which must be accounted for in the profile. Accordingly, the Table coordinate values are for a nominal component. It will therefore be appreciated that plus or minus typical manufacturing tolerances are applicable to the Table coordinate values and that a component having a profile substantially in accordance with those values includes such tolerances. For example, a manufacturing tolerance of about +−0.030 inches (0.76 mm) should be considered within design limits for the component. Thus, the mechanical and aerodynamic function of the component is not impaired by manufacturing imperfections and tolerances, which in different embodiments may be greater or lesser than the values set forth in the disclosed Tables. As appreciated by those in the art, manufacturing tolerances may be determined to achieve a desired mean and standard deviation of manufactured components in relation to the ideal component profile points set forth in the disclosed Tables. 
     In addition, the component may also be coated for protection against corrosion and oxidation after the component is manufactured, according to the values of the Tables and within the tolerances explained above. Consequently, in addition to the manufacturing tolerances for the Table coordinates values, there may also be an addition to account for the coating thickness. It is contemplated that greater or lesser coating thickness values may be employed in alternative embodiments of the invention. Consequently, in addition to the manufacturing tolerances, there is also a modification to the Table coordinate values to account for potential coating thicknesses. It is contemplated that greater or lesser coating thickness values may be employed in alternative embodiments of the invention. 
     Referring to  FIG. 1 , assembly of the compressor rotor  32  within the disclosed ACM  20  includes mounting of the turbine rotor  34 , fan rotor  36  to the main shaft  30 . The example turbine rotor  34  includes a guide lug portion  78  that is received into one end of the seal shaft  62 . The compressor rotor  32  is attached to the main shaft  30  such that the guide lug  60  is received within a second end of the seal shaft  62  opposite the side on which the turbine rotor  34  is secured. The fastener  64  is attached to the main shaft  30  and holds the compressor rotor  32  in place. The diffuser  38  is then secured to an ACM housing portion  80 . A portion of the diffuser  38  includes a contoured surface  82  that follows the tip surface  68  of the compressor rotor  32  with a clearance to provide for rotation. The example diffuser  38  defines the inlet  42  to the compressor rotor  32  and the radially extending outlet passages  44  into a compressor outlet passage  82  defined by the compressor housing  40 . The compressor outlet passage  82  is at least partially defined by the compressor housing  40  attached and sealed to the diffuser  38 . 
     Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the scope and content of this invention.