Abstract:
An example portable boroscope assembly for inspecting passages within a turbomachine blade includes a boroscope probe and a display screen. The display screen is configured to show images of areas inspected by the boroscope probe. A battery powers the display screen. A protective case holds at least the display screen and the battery. The protective case defines an aperture. The display screen is viewable through the aperture.

Description:
BACKGROUND 
       [0001]    This disclosure relates generally to inspecting turbomachine components and, more particularly, to inspecting turbomachine blades using a portable boroscope. 
         [0002]    Turbomachines include various blades. Some blades rotate during operation. Other blades remain stationary. The blades may operate in high temperatures environments. Exposure to sufficiently high temperatures can damage the blades as is known. Accordingly, many blades include internal passages that communicate a flow of air through the blades. The flow of air removes thermal energy from the blades to cool the blades. 
         [0003]    Blades become worn over time, and some blades may become damaged. Operating the turbomachine with worn or damaged blades can reduce the efficiency of the turbomachine. Replacement blades are expensive to manufacture. Thus, it is often desirable to refurbish worn or damaged blades, rather than replacing worm or damaged blades with new blades. 
         [0004]    The internal passages in the blades are periodically inspected during a refurbishing procedure. The inspection identifies blockages, internal damage, etc. The internal passages of newly manufactured blades typically undergo a similar inspection. Technicians may use bench-based boroscopes to inspect the internal passages. Inspecting the blades using bench-based boroscopes is time consuming as the blades must be moved to the location of the bench-based boroscope. 
       SUMMARY 
       [0005]    An example portable boroscope assembly for inspecting passages within a turbomachine blade includes a boroscope probe and a display screen. The display screen is configured to show images of areas inspected by the boroscope probe. A battery powers the display screen. A protective case holds at least the display screen and the battery. The protective case defines an aperture. The display screen is viewable through the aperture. 
         [0006]    Another example portable boroscope assembly for inspecting passages within a turbomachine blade includes a camera and a probe tip operatively coupled with the camera. The assembly also includes a display and a light that are operatively coupled to the probe tip. A battery powers the camera, the display, and the light. The protective case holds at least the display and the battery. 
         [0007]    An example method of inspecting a turbomachine blade using a boroscope inspection assembly includes powering a boroscope inspection device using a battery and inspecting a fluid passage established within a turbomachine blade using the boroscope inspection device. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0008]    The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the detailed description. The figures that accompany the detailed description can be briefly described as follows: 
           [0009]      FIG. 1  shows a cross-section view of an example turbomachine. 
           [0010]      FIG. 2  shows a perspective view of an example blade from the  FIG. 1  turbomachine. 
           [0011]      FIG. 3  shows an end view of the  FIG. 2  blade. 
           [0012]      FIG. 4  shows an example boroscope inspection device used to inspect the  FIG. 2  blade. 
           [0013]      FIG. 5  shows another view of the  FIG. 4  boroscope inspection device. 
           [0014]      FIG. 6  shows a close-up view of a probe of the  FIG. 4  boroscope inspection device. 
           [0015]      FIG. 7  shows a section view at line  7 - 7  in  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Referring to  FIG. 1 , an example turbomachine, such as a gas turbine engine  10 , is circumferentially disposed about an axis  12 . The gas turbine engine  10  includes a fan  14 , a low pressure compressor section  16 , a high pressure compressor section  18 , a combustion section  20 , a high pressure turbine section  22 , and a low pressure turbine section  24 . Other example turbomachines may include more or fewer sections. 
         [0017]    During operation, air is compressed in the low pressure compressor section  16  and the high pressure compressor section  18 . The compressed air is then mixed with fuel and burned in the combustion section  20 . The products of combustion are expanded across the high pressure turbine section  22  and the low pressure turbine section  24 . 
         [0018]    The high pressure compressor section  18  includes a rotor  32 . The low pressure compressor section  16  includes a rotor  33 . The rotors  32  and  33  are configured to rotate about the axis  12 . The example rotors  32  and  33  include alternating rows of rotating airfoils or rotating blades  34  and static airfoils or static blades  36 . The static blades  36  may also be referred to as static vanes. 
         [0019]    The high pressure turbine section  22  includes a rotor  26 . The low pressure turbine section  24  includes a rotor  27 . The rotors  26  and  27  are configured to rotate about the axis  12  in response to expansion to drive the high pressure compressor section  18  and the low pressure compressor section  16 . The example rotors  26  and  27  include rotating arrays of blades  28 , for example. 
         [0020]    The example turbomachine described in this disclosure is not limited to the two spool gas turbine architecture described, however, and may be used in other architectures, such as the single spool axial design, a three spool axial design, and still other architectures. That is, there are various types of gas turbine engines, and other turbomachines, that can benefit from the examples disclosed herein. 
         [0021]    Referring to  FIGS. 2-3 , an example blade  50  from the  FIG. 1  turbomachine extends axially from a base  52  to a tip  54 . The blade  50  includes a radially extending airfoil  56 . 
         [0022]    In this example, the blade  50  is one of the rotating blades from the rotor  32 . In other examples, the blade  50  is a stationary blade, or a blade from the one of the turbine sections  26  and  27 . 
         [0023]    The example blade  50  has been used within the engine  10  and is being refurbished for the purpose of reinstallation into the engine  10 . Example refurbishing processes may include acid stripping blades, reapplying coatings to blades, adding new tips to blades, adding additional material to worn areas of blades. 
         [0024]    The example blade  50  establishes a plurality of internal passages  58 . In this example, apertures  60  established in the base  52  represent the starting point for internal passages  58 , and cooling holes  62  represent the termination point. During operation, a cooling airflow moves from an air supply  61  into the internal passages  58  through the apertures  60 . The cooling airflow exits the internal passages  58  through the cooling holes  62 . 
         [0025]    The cooling airflow moving through the internal passages  58  of the blade  50  cools the blade  50 . Also, air exiting the internal passages  58  through the cooling holes  62  may cool the blade  50  by film cooling, for example. The internal passages  58  are a type of fluid communication paths. 
         [0026]    Only a few internal passages  58  and cooling holes  62  are shown in this example. A person having skill in this art and the benefit of this disclosure would understand that many more internal passages  58  and cooling holes  62  may be established within the blade  50  depending on specific design requirements. Further, although the example internal passages  58  are relatively linear, other examples may include serpentine passages, or passages that follow other paths. 
         [0027]    Referring now to  FIGS. 4 and 5  with continuing reference to  FIGS. 2 and 3 , an example boroscope inspection device  66  is used to inspect the internal passages  58  of the blade  50 . The inspection device  66  may reveal internal passages  58  that are blocked, for example. Such blockages prevent a cooling airflow from moving through some portions of the blade  50 , which can undesirably result in thermal energy concentrations within the blade  50 . The inspection device  66  may be used to inspect a blade that is being refurbished or to inspect a newly manufactured blade. 
         [0028]    The example inspection device  66  includes a probe  68  having a probe tip  70 . A video camera  72  is removably attachable to the probe  68 . In some examples, an adapter may be required to attach the video camera  72  and the probe  68 . 
         [0029]    The example video camera  72  is operatively linked to a display  74  and a battery  76 . The display  74  includes a display screen  78  that shows images inspected by the probe  68 . A person having skill in this art and the benefit of this disclosure would understand how to display the images of the inspected areas on the display screen  78 . The display screen is a 7 inch (17.78 centimeter) display screen in this example. The images show a blockage within the internal passages  58 . 
         [0030]    In this example, the display  74  and the video camera  72  are both powered exclusively by the battery  76 . The example battery  76  is a 12 volt, 5.2 amp rechargeable battery. The life of the example battery  76  is about 3.0 hours. A recharging station may be used to recharge the battery  76  when the inspection device  66  is not in use. 
         [0031]    The example inspection device  66  also includes a light  80  that is removably attachable to the probe  68 . The light  80  is used to illuminate areas inspected by the probe  68 , such as the internal passages  58 . 
         [0032]    A wriststrap  81  is attached to the light  80  to help an inspector secure the probe  68  and the light  80  during an inspection procedure. 
         [0033]    The example inspection device  66  includes a protective case  82  that holds the battery  76 , the display  74 , and the video camera  72 . During an inspection procedure, the video camera  72  may be removed from the protective case  82  or may stay within the protective case  82 . The probe  68  typically remains outside the protective case  82 , along with the light  80 , regardless the location of the video camera  72 . 
         [0034]    The example protective case includes a lid  84  that establishes an aperture  86 . The aperture  86  allows a user, such as the inspector, to view at least a portion of the display screen  78  when the lid  84  is closed. A clear protective cover  87  is used in this example to protect against damage to the screen  78  through the aperture  86 , which is about 1.5 inches (3.81 cm) in this example. The example protective case  82  is 14 inches (45.56 cm) long, 10 inches (25.4 cm) wide, and 3.5 inches (8.89 cm) tall. 
         [0035]    In this example, the lid  84  of the protective case  82  is closed when the lid  84  is placed over a base  88  of the protective case  82 . The lid  84  is hinged to the base  88  in this example.  FIG. 4  shows the protective case  82  in an open position, and  FIG. 5  shows the protective case  82  in a closed position. Notably, an inspection may be carried out with the protective case  82  in a closed position. 
         [0036]    An on/off switch  90  is secured within the lid  84  of the example protective case  82 . An inspector actuates the on/off switch  90  to selectively supply power to the video camera  72  and the display  74  from the battery  76 . The protective case  82  also includes a charging location (not shown) for the battery  76  so that the battery  76  may be recharged at the 110V recharging station without requiring the operator to open the protective case  82 . Wiring connects the various components of the inspection device  66  where needed. 
         [0037]    During an inspection procedure utilizing the inspection device  66 , the inspector may transport the inspection device  66  to the blade  50  using a carrying handle  83  established within the protective case  82 . The probe tip  70  is then inserted through the aperture  60  established within the base  52  of the blade  50 . The inspector may be required to attach the probe  68  and light  80  to the video camera  72  prior to insertion of the probe tip  70 . Notably, the shape of the probe tip  70  allows the inspector to inspect the full radial length of the internal passages  58  by continuing to insert the probe tip  70  into the aperture  60 . The probe tip  70  is flexible, which also facilitates inspection. 
         [0038]    The inspection may reveal, for example, foreign material, corrosion, and damage within the internal passages  58 . The probe tip  70  may be used to inspect internal trip strips in some examples. In some examples, the inspection utilizing the inspection device  66  is coupled with inspections utilizing a magnitoscope, which may improve detection of corrosion. 
         [0039]    Typical blades inspected by the inspection device  66  are between 3 inches (76.2 mm) and 10 inches (254 mm) long. The example probe tip  70  is longer than the typical blades to provide the operator with adequate length to manipulate the position of the probe tip  70 . Although described as a inspection device  66  used to inspect the internal passages  58  of a blade  50 , the inspection device  66  may be used to inspect other areas of the engine  10  requiring a relatively slender probe tip. 
         [0040]    Referring now to  FIGS. 6 and 7  with continued reference to  FIG. 3 , an example probe tip  70  has a length l that is between 17⅜ inches (44.1325 cm) and 29⅜ inches (74.6125 cm). In one specific example, the probe tip  70  is 25 inches (63.5 cm) with a tolerance of +/−⅛ inch (3.175 cm). The diameter d of the example probe tip  70  is about 0.03 inches (0.762 mm). Other examples may include probe tips having diameters that are between 0.02 inches (0.508 mm) and 0.04 inches (1.016 mm). The relatively slender nature and flexibility of the example probe tip  70  facilitates insertion of the probe tip  70  into the internal passages of the blade  50 . Typically, a ratio of the length l of the probe tip  70  to the diameter d of the probe tip  70  is between 434 and 1,469. 
         [0041]    Features of the disclosed examples include an inspection device that may be transported to the location of a blade requiring inspection, rather than requiring transport of the blade to the inspection device. Another feature of the example inspection device is a probe tip suitable for inspection fluid communication paths within turbomachine blades. The inspection device displays images from a display screen within a protective case that also houses the battery. 
         [0042]    The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. Thus, the scope of legal protection given to this disclosure can only be determined by studying the following claims.