Abstract:
A device for plugging an axially-aligned bore in a shaft of a gas turbine engine comprises a plug. A sealing body of the plug is sealingly received in a bore of the shaft. Legs project from the sealing body and are displaceable between a normally contracted position in which the legs are radially inward relative to a periphery of the bore, and a deployed position in which the legs project radially outward and engage with shaft projections within the bore of the shaft. A wedge is operatively engaged to the plug for movement of the wedge relative to the plug. The wedge comprises a portion in operative contact with the legs of the plug unit to displace the legs between positions as a response to movement of the wedge. A gas turbine engine and a method for plugging a shaft are provided.

Description:
FIELD OF THE INVENTION 
       [0001]    The present application pertains to plug devices to plug shafts in gas turbine engines. 
       DESCRIPTION OF THE PRIOR ART 
       [0002]    In some instances, it may be required to plug gas turbine engine shafts to keep the oil within the shaft. For instance, a first shaft may require a plug when a mating second shaft is not connected to the shaft. However, the plug is exposed to oil and oil pressures and temperatures. The design of a plug must take such factors into consideration. 
       SUMMARY 
       [0003]    Therefore, in accordance with a general aspect, there is provided a device for plugging an axially-aligned bore in a shaft of a gas turbine engine, comprising: a plug comprising a sealing body shaped to be sealingly received in a bore of the shaft, and legs projecting from the sealing body and being displaceable between a normally contracted position in which the legs are radially inward relative to a periphery of the bore, and a deployed position in which the legs project radially outward and are adapted to engage with shaft projections within the bore of the shaft; and a wedge operatively engaged to the plug for movement of the wedge relative to the plug, the wedge comprising a portion in operative contact with the legs of the plug unit to displace the legs between said positions as a response to said movement of the wedge. 
         [0004]    Further in accordance with the present disclosure, there is provided A gas turbine engine comprising: a shaft defining an axially-aligned bore with projections within the bore; and a device for plugging the shaft comprising: a plug comprising a sealing body sealingly received in the bore of the shaft, and legs projecting from the sealing body and being displaceable between a normally contracted position in which the legs are radially inward relative to a periphery of the bore, and a deployed position in which the legs project radially outward in engagement with said projections within the shaft; and a wedge operatively engaged to the plug for movement of the wedge relative to the plug, the wedge comprising a portion in operative contact with the legs of the plug to displace the legs between said positions as a response to said movement of the wedge. 
         [0005]    Still further in accordance with the present disclosure, there is provided a method for plugging a shaft of a gas turbine engine with a plug device, comprising: sealingly engaging the plug device in the shaft by inserting the plug device in an axially-aligned bore of the shaft; and securing the plug device to the shaft by deploying legs of the plug device radially into contact with shaft projections within the bore. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a schematic view of a gas turbine engine, illustrating a shaft of the type plugged by a plug device of the present disclosure; 
           [0007]      FIG. 2  is a perspective view of the plug device of the present disclosure in an assembled condition; 
           [0008]      FIG. 3  is an exploded view of the plug device of  FIG. 2 ; 
           [0009]      FIG. 4  is a sectional view of the plug device of  FIG. 2 , with legs in a deployed position in a shaft; and 
           [0010]      FIG. 5  is a sectional view of the plug device of  FIG. 2  with the legs being in a contracted position. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0011]      FIG. 1  illustrates a turbofan gas turbine engine  10  of a type preferably provided for use in subsonic flight, generally comprising in serial flow communication a fan  12  through which ambient air is propelled, a multistage compressor  14  for pressurizing the air, a combustor  16  in which the compressed air is mixed with fuel and ignited for generating an annular stream of hot combustion gases, and a turbine section  18  for extracting energy from the combustion gases. 
         [0012]    Referring concurrently to  FIGS. 2 and 3 , a plug device in accordance with the present disclosure is generally shown at  20 . The plug device  20  is used with a hollow shaft  23  ( FIG. 1  and  FIG. 4 ) that is located within the gas turbine engine  10 . The plug device  20  has an annular plug unit  24  with a wedge unit  26  inserted into the annular plug unit  24 . A nut  28  may secure the wedge unit  26  to the annular plug unit  24 . 
         [0013]    The annular plug unit  24  is the main component of the plug device  20  blinding the shaft  23 , and is sealingly inserted in the shaft  23 . 
         [0014]    The wedge unit  26  expands the diameter of the annular plug unit  24  for the plug device  20  to be releasably connected to the shaft  23 . 
         [0015]    Referring to  FIG. 4 , the shaft  23  is of the type being hollow, with an inlet end  31 . The inlet end  31  may form a female end for the shaft  23  to be connected to other components, such as another shaft. Accordingly, the shaft  23  has an axially-aligned bore  32  with inner projections, such as splines  33 . The shaft  23  may feature other types of projections, such as inner flanges, shoulders of channels, etc. 
         [0016]    Referring concurrently to  FIGS. 2 to 5 , the annular plug unit  24  has an annular body  40 , also referred to as a sealing body. An annular channel  41  is defined in an outer surface of the annular body  40  and is devised to receive one or more annular seals  42 . The annular seal  42  is any appropriate type of seal suited to be in contact with the fluid which must be kept within the shaft  23 , such as oil. For instance, the annular seal  42  is an O-ring, wiper seal, etc. 
         [0017]    A throughbore  43  is defined in the annular body  40 . The throughbore  43  may be tapped as shown by tapping  44 . The annular body  40  may further have counterbores  45  and  46  on opposite sides of the throughbore  43 . Locating pins  47  project axially from the annular body  40  and are oriented towards the wedge unit  26 . Other arrangements are possible for the annular body  40 . For instance the annular body  40  may be without the counterbores  45  and/or  46 . Moreover, the throughbore  43  may not have any tapping  44 , and may not be concentric relative to the annular body  40 . The annular body  40  is made of any appropriate material to sustain the pressures and temperatures of a gas turbine engine. For instance, the annular body  40  may be machined from a metallic material. The body  40  may have other configurations as alternatives to being annular, as long as the body  40  is sized to plug the shaft  23  with its outer surface. 
         [0018]    Still referring to  FIGS. 2 to 5 , legs  50  project axially from one end of the annular body  40 . The legs  50  may be integral with the annular body. The annular plug unit  24  is shown having five legs  50  radially spaced apart along a radius of the annular body  40 . The annular plug unit  24  may have more or less than the five legs  50  shown in  FIG. 3 . Feet  51  are part of the legs  50  and project radially outward at the free end of each of the legs  50 . The feet  51  are projections by which the annular plug unit  24  will grasp projections within the shaft  23 . Each of the feet  51  may feature a ramp  52  facing toward the annular body  40 . 
         [0019]    Referring to  FIGS. 3 to 5 , the wedge unit  26  is shown having a stem  60 . The stem  60  may be a threaded rod, as shown in the illustrated embodiment. A skirt  61  is at one end of the stem  60 . The skirt  61  has a base  62 . The base  62  has a periphery that matches that of the counterbore  45  of the annular body  40 . An annular channel  63  is defined in a peripheral surface of the base  62  and accommodates a portion of one or more seals  64 . Therefore, as shown in  FIG. 4 , when the wedge unit  26  is mated to the annular plug unit  24 , the base  62  of the skirt  61  is matingly received in the counterbore  45 , with the seal  64  closing the gap therebetween. The skirt  61  has a wedge portion  65  extending from the base  62 . 
         [0020]    According to another embodiment, the wedge unit  26  is made of a metallic material. The material of the wedge unit  26  must be chosen to sustain the pressures and temperatures related to gas turbine engine use. It is pointed out that the annular seal between the wedge unit  26  and the annular plug unit  24  may be located at other positions. Moreover, it is considered to size of the annular plug unit  24  and the wedge unit  26  such that the seal  64  is not required. 
         [0021]    The wedge unit  26  and the annular plug unit  24  are sized such that the legs  50  of the annular plug unit  24  do not contact the wedge  65  at the end of the skirt  61  in a contracted configuration of the plug device  20  shown in  FIG. 5 . In the contracted configuration, the stem  60  of the wedge unit  26  is engaged into the throughbore  43 . Therefore, a rotation of the wedge unit  26  along its longitudinal axis will cause it to move along the longitudinal axis of the plug device  20  and thus of the shaft  23 , by the screwing engagement between the stem  60  and the tapped bore  43 . For this reason, the stem  60  has a tooling end  66  (i.e., flat engagement surfaces) by which an appropriate tool may be used to rotate the wedge unit  26 . It is pointed that other types of joints may be formed between the wedge unit  26  and the plug unit  24 . According to an embodiment, any appropriate one-degree-of-freedom translational joint may be used, such as a sliding joint, a cylindrical joint, etc, as alternatives to the screw joint. 
         [0022]    The plug device  20  in the contracted configuration of  FIG. 5  is sized to be inserted in the bore  32  of the shaft  23 , with the legs  50  being in a contracted position. The bore  32  of the shaft  23  defines a throat by the presence of the splines  33  or like projections. However, the diameter of the plug device  20  is small enough for the feet  51  to move axially beyond the splines  33  in the shaft  23 . 
         [0023]    Once the feet  51  are beyond the splines  33 , the wedge unit  26  is moved axially relative to the annular plug unit  24 . In the illustrated embodiment, the wedge unit  26  is screwingly rotated. The annular plug unit  24  does not rotate because of the alignment pins  47  being engaged with the splines  33 . As the wedge unit  26  moves axially along the shaft  23 , the wedge portion  65  will contact the end of the legs  50 , thereby pushing the feet  51  radially outwardly, to a deployed position of the legs. The feet  51  therefore come into contact with the splines  33 , causing the plug device  20  to remain captive in the shaft  23 . The nut  28  may then be used to block the wedge unit  26  and the annular plug unit  24  in the deployed configuration. 
         [0024]    Accordingly, the plug device  20  being in the deployed configuration of  FIG. 4  is held captive inside the shaft  23 , and the nut  28  prevents any substantial movement between the annular plug unit  24  and the wedge unit  26 . The seal  42  blocks the gap between the bore  32  of the shaft  23  and the outer surface of the annular body  40  of the plug unit  24 . Similarly, the seal  64  blocks the gap between the base  62  of the wedge unit  26  and the peripheral surface of the counter bore  45  of the annular plug unit  24 . 
         [0025]    In order to remove the plug device  20 , the nut  28  is removed if there is such a nut  28 . Then, the wedge unit  26  is rotated in the opposite direction so as to bring the plug device  20  to the contracted configuration of  FIG. 5 . Once the contracted configuration of  FIG. 5  is reached, the plug device  20  may be pulled out of the annular shaft  23 . 
         [0026]    The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.