Abstract:
A housing for use in an air machine includes a housing body for housing at least one rotor. The housing body has at least one conduit for connection to a connecting conduit. The conduit has a drain hole adjacent an end of the conduit. The drain hole is formed at an angle relative to a plane made perpendicular to a center axis of said conduit. An air machine, an air machine assembly and a method are also disclosed.

Description:
BACKGROUND 
       [0001]    This application relates to a housing for an air machine, wherein drain holes are provided to drain accumulated water. 
         [0002]    Air machines are known and are utilized to supply air for various uses on aircraft. In one known air machine, compressed air from another system on the aircraft is delivered to a compressor section on the air machine. The air is further compressed and then delivered across to a first stage turbine and then a second stage turbine. 
         [0003]    Since the air machines are mounted on an aircraft, space is at a premium. The “plumbing” associated with the air machine, including its housing, associated heat exchangers, and connecting conduits, are all tightly packed and communicate within a small space. 
         [0004]    Within the air machines, there are a number of locations in which water, and in particular, water having drained from the heat exchangers, may accumulate. When this accumulated water is ingested into the rotors, various operational concerns are raised. As an example, the compressor may experience surge conditions due to the water. Water is also undesirable in the turbines. 
       SUMMARY OF THE INVENTION 
       [0005]    A housing for use in an air machine includes a housing body for housing at least one rotor. The housing body has at least one conduit for connection to a connecting conduit. The conduit has a drain hole adjacent an end of the conduit. The drain hole is formed at an angle relative to a plane made perpendicular to a center axis of said conduit. 
         [0006]    An air machine, an air machine assembly, and a method are also disclosed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a cross-sectional view of an example air machine. 
           [0008]      FIG. 2A  is a vertically lower view of a combined air machine assembly. 
           [0009]      FIG. 2B  is a view looking vertically downwardly on the  FIG. 2A  assembly. 
           [0010]      FIG. 3  is a view of a turbine housing associated with the air machine. 
           [0011]      FIG. 4  is a cross-sectional view along lines  4 - 4  of  FIG. 3 . 
           [0012]      FIG. 5A  is a view along the circled area  5  of  FIG. 3 . 
           [0013]      FIG. 5B  is an enlarged portion of the area shown in  FIG. 5A . 
           [0014]      FIG. 6  is a view of a compressor housing. 
           [0015]      FIG. 7A  is a cross-sectional view through a portion of the  FIG. 6  housing. 
           [0016]      FIG. 7B  is an enlarged view of the  FIG. 7A  structure. 
           [0017]      FIG. 7C  shows the  FIGS. 7A and 7B  structure in an assembled position. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    An air machine  20  is illustrated in  FIG. 1 , having a fan  22  moving air. A compressor  24  receives compressed air in a compressor inlet  25  from another compressor, and delivers that air through compressor outlet  39 , and to a first stage turbine  26 . The air then passes across a second stage turbine  28 . The turbines  26  and  28  expand the compressed air, and drive the compressor  24  and fan  22 . 
         [0019]    A turbine housing  30  is illustrated that houses the two turbine stages  26  and  28 . An outlet  34  of the first turbine  26  is formed within the housing  30  and communicates with an inlet  31  of a second turbine stage. As shown in dashed outline in  FIG. 1 , a conduit  32  is connected to the turbine inlet  31 . A similar connection will be associated with the turbine outlet  34 . 
         [0020]    In addition, a compressor housing  38  houses the compressor rotor  24 . Compressor housing  38  includes compressor outlet  39 . A conduit  36  connects to the compressor outlet  39 , and is shown in phantom in this view. 
         [0021]      FIG. 2A  shows an assembly  40  which combines two of the air machines  121  and  122  of  FIG. 1 . The turbine housing  30  and the compressor housing  38  are shown in this view. As shown, there are three locations  52 ,  51  and  53  wherein water may accumulate at the vertically lower positions. The water may typically drain from heat exchangers  150 , which are mounted atop the combined system  40 . 
         [0022]    As shown in  FIG. 2B , the combined system  40  has the air machines  121  and  122  mounted in vertically reversed positions. Thus, the area  53  associated with the machine  122  is at a vertically upper location  53  in the machine  121 . Similarly, the areas  51  and  52  associated with machine  122  are in vertically upper locations. As such, the accumulation problems associated with areas  51 ,  52  and  53  of  FIG. 2A  are not a concern in the positions  53 ,  51  and  52  of  FIG. 2B . 
         [0023]      FIG. 3  shows an end view of the turbine housing  30 . A conduit  34  is illustrated having an inner radius R 1 . In one embodiment, R 1  was 2.120-2.130″ (5.384-5.410 cm). A cross-section  4 - 4  is taken through this conduit. The conduit  34  is formed in a flange  100 , which is centered at an angle C from a line X. Line X is drawn perpendicular to a plane through another conduit  31  with line X passing through a center D of the main housing. The angle C is 31-36° in one embodiment. The cross-section  4 - 4  is taken at a vertically lower portion of the conduit  34  in the flange  100 . 
         [0024]    At the opposed end of the housing  30  is the conduit  31 . Structure within a circle identified by the numeral  5  will be explained in detail below. 
         [0025]      FIG. 4  is taken along line  4 - 4  and shows detail of the conduit  34 . As shown, the conduit  34  has an enlarged portion  60  leading into a ledge  62 , which then leads into a smaller portion  162  at an axial end of the conduit  34 . As can be appreciated, this defines a well  59  in which water can accumulate. This is area  51  (see  FIGS. 2A and 2B ). Thus, a drain hole  64  is formed through the ledge  62 . In addition, a second drain hole portion  66  is formed through an outer lip  163  of the smaller portion  162 . The drain hole  64 / 66  has a diameter d 1 . In one embodiment, d 1  was 0.074-0.082″ (0.187-0.208 cm). As shown, the drain hole  64 / 66  is generally parallel to an axis Y extending through the center of the conduit  34 . 
         [0026]    In embodiments, a ratio of R 1  to d 1  was between 25 and 29. 
         [0027]      FIG. 5A  shows details of the conduit  31 . As shown, the conduit  31  is attached to another conduit  32  at this location. A drain hole  72  is formed through the conduit  31  to drain water from a potential sump area  71 . This is the area of concern  52 , as shown in  FIG. 2A . The central bore in conduit  31  has a radius R 2 . In one embodiment, R 2  was 2.400-2.460″ (6.096-6.248 cm). 
         [0028]      FIG. 5B  shows details of the drain hole  72 . As shown, there is an outer countersunk bore having a diameter d 2 , and inner smaller portion  82  having a diameter d 3 . Smaller portion  82  extends to the outer surface and provides the actual drain. The drain hole  72  is cut at an angle A relative to a plane extending perpendicular through a central axis Z (see  FIG. 5A ) of the conduit  31 . The angle A is 45° one embodiment. Angle A may be between 43 and 47° in embodiments. 
         [0029]    In one embodiment, d 2  was 0.074-0.122″ (0.187-0.310 cm) and d 3  was 0.074-0.082″ (0.187-0.208 cm). In embodiments, a ratio of d 2  to d 3  is between 0.9 and 1.7, and a ratio of R 2  to d 2  was between 19.5 and 33.5. 
         [0030]      FIG. 6  shows the compressor housing  38  and the conduit  39 . 
         [0031]      FIG. 7A  is a cross-section through line  7 - 7  of  FIG. 6 .  FIG. 7  illustrates a portion of the conduit  39 , and shows an outer lip  88 . The outer lip  88  receives a drain hole  100 . As shown in  FIG. 5B , the drain hole  100  is centered on an angle B relative to a plane drawn perpendicular to a central axis W of the conduit  39 . Angle B is 20° in one embodiment. Angle B may be between 18 and 22° in embodiments of this invention. 
         [0032]    As shown, the conduit  39  has a radius R 3  at an outer end. R 3  was 2.300-2.320″ (5.842-5.893 cm) in embodiments of this invention. 
         [0033]    As shown in  FIG. 7B , the drain hole  100  has an outer countersunk portion  98  of a diameter d 5 . In one embodiment, d 5  was 0.074-0.132″ (0.188-0.335 cm). This countersunk portion extends partially into a chamfer portion  94  of the conduit lip  88 . A portion of the countersunk portion  98  is also formed on an outer face  92  of the lip  88 . 
         [0034]    An inner drain portion  96  has a smaller diameter d 4 . In one embodiment, d 4  was 0.074-0.082″ (0.187-0.208 cm). Drain portion  96  extends to the outer periphery of lip  88 , and is the actual drain. 
         [0035]    In embodiments, a ratio of R 3  to d 4  was between 28 and 31.5. A ratio of d 4  to d 5  was between 0.5 and 1.2. 
         [0036]      FIG. 7C  shows the conduit  39  attached to the conduit  36 . As can be appreciated, there is a potential area  110  wherein water could accumulate and that water will drain outwardly of the drain hole  96 . This is the area of concern  53  as shown in  FIG. 2A . 
         [0037]    As can be appreciated, the drain holes provided to drain water from the areas of concern  51 ,  52  and  53  will provide drainage in the locations shown in  FIG. 2A . At the same time, within the machine  40 , the areas  51 ,  52  and  53  shown in  FIG. 2B  will not raise a concern. Still, those areas are provided with drain holes such that the same components can be utilized for both orientations without unduly interfering with the operation of the machine or its efficiency. The drain holes have been designed, positioned and sized to minimize any concerns. 
         [0038]    For purposes of interpreting the claims in this application, it should be understood that the specific dimensions would come with a margin of error for manufacturing tolerances, etc. This margin of error would be plus or minus 0.010″ (0.0254 cm). When interpreting the scope of any claims that may include a dimension, the margin of error should be taken into account. 
         [0039]    In a method of replacing either housing  30  or  38 , an existing housing is unbolted and removed from the air machine  20 . The fluid connections are disconnected. Then, the new housing is brought in, and positioned around the associated rotor. The new housing is then attached to the air machine  20 . Further, the fluid connections are reconnected to the new housing. 
         [0040]    Embodiments of this invention have been disclosed, however a worker of ordinary skill in the art would recognize that certain modifications will come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.