Abstract:
A turbofan jet engine includes an outer casing supported by arms, an inner casing facing the outer casing, ancillaries, and an ancillaries distribution support. The ancillaries distribution support is formed along the axis of an arm on the inner casing. The ancillaries distribution support includes a first sole plate for reception of ancillaries on the outer side of the inner casing and a second sole plate for reception of ancillaries on the inner side of the inner casing. Such a turbofan jet engine reduces the longitudinal dimension necessary for the ancillaries to pass through.

Description:
TITLE OF THE INVENTION 
   The invention relates to a turbofan jet engine. 
   BACKGROUND OF THE INVENTION 
   I. Field of the Invention 
   A turbofan jet engine functionally comprises an air inlet duct, a fan, a compressor, a combustion chamber, a turbine and an exhaust nozzle. These various elements are contained in the casings. 
   The turbofan jet or turbojet engine also comprises an internal secondary flow casing around these casings, in the form of a ring that contains the secondary airflow on its external surface. The secondary airflow corresponds to air entrained by the fan that does not penetrate into the compressor. This ring comprises means of opening into two half-shells, so that the core of the turbojet engine can be accessed. The core of the turbojet engine means elements in the turbojet engine located within the chamber defined by the internal secondary flow casing. 
   Some fluids necessary for operation of the turbojet engine such as fuel and oil must be routed from the outside of the turbojet engine towards its core. These fluids are used particularly to supply the combustion chamber with fuel, the various elements of the engine with lubrication oil, various discharge valve actuation jacks, the compressor variable pitch, control of the clearance of high pressure and low pressure turbine casings, etc. 
   Fluids are routed through pipes commonly called ancillaries. The invention relates particularly to the passage of ancillaries along the support arm of a turbojet engine casing, called the intermediate casing. 
   II. Description of Related Art 
     FIG. 1  shows a partial view of a turbojet engine  1  according to prior art. This turbojet engine comprises the outer ring  2  of a so-called intermediate casing on the output side of the fan blade retention casing, to which the forward suspension of the turbojet engine is traditionally fixed to an aircraft. The intermediate casing also comprises radial arms  3 . An inner ring  4  is arranged adjacent to its outer ring  2 , this inner ring  4  comprising a bearing step  5  of the secondary flow inner casing, not shown. 
   Some ancillaries  6  have to be transferred from the outside of the intermediate casing to the core of the turbojet engine  1 . This transfer is usually made along an arm  3  of the intermediate casing, the ancillaries  6  opening up in the core of the turbojet engine  1  at the inner ring  4 . 
   The turbojet engine  1  presented will be installed on an aircraft with a fairly small ground clearance. Therefore, its nacelle is flattened near the bottom and spreads out on its sides. For safety reasons, the ancillaries  6  must not pass in the bottom part of the turbojet engine  1 , if the turbojet engine  1  rubs along the ground. Therefore, they are routed along an arm  3  of the intermediate casing separated from the global vertical plane of symmetry of the turbojet engine  1 . 
   The ancillaries  6  pass through the outer ring  2  of the intermediate casing and are contained between the outer ring  2  and the inner ring  4  within an arm  7 , which protects them and guides the secondary airflow. The ancillaries  6  are fixed at the inner ring  4  onto a plate  8 , by nuts on each side of the plate  8 . 
   There is a fairly large number of these ancillaries  6 , for example there may be eleven, and they must be guided in a fairly congested area. Furthermore, they cannot be located outside the section defined by projection on the transverse plane of the support arm  3  of the intermediate casing, in a plane transverse to the turbojet engine axis, for aerodynamic reasons related to the secondary airflow. Therefore, they have to be spread longitudinally on the plate  8 . The plate  8  extends longitudinally beyond the inner ring  4  and projects into the opening area of the secondary flow internal casing cowls, particularly due to the surface area necessary for screwing the nuts, since it cannot be located in the vertical plane of symmetry containing the cowl opening hinge, as we have seen above. 
   Therefore, a recess has to be formed on a cowl of the inner secondary flow casing, for the plate  8  to pass through when the cowls are opened and closed. The part  8  must be adapted and must fill this recess, to assure continuity of the airflow guidance between the inner ring  4  and the surface of the inner secondary flow casing, at the recess. Production costs of the said casing and maintenance cost of the turbojet engine are correspondingly increased. 
   BRIEF SUMMARY OF THE INVENTION 
   This invention is designed to reduce production costs of the inner secondary flow casing, to simplify turbojet engine maintenance and to facilitate access to the turbojet engine core at the ancillaries along the arm of the intermediate casing. 
   According to the invention, a double flow turbojet engine comprising an outer casing supported by arms, an inner casing facing the outer casing and ancillaries is characterised by the fact that an ancillaries reception support is formed along the axis of an arm, on the inner casing, comprising a first sole plate for reception of ancillaries on the outer side of the inner casing. 
   For the purposes of this description, axis means the centreline or the direction of the gas flow around the arm. 
   Thus, due to the ancillaries distribution support according to the invention, there is no longer any need to make a cut out in the inner secondary flow casing of the turbojet engine since the longitudinal dimension is reduced. 
   Preferably, the first sole plate comprises ancillary reception ducts. 
   Advantageously, the ancillaries distribution support comprises a second sole plate for the distribution of ancillaries on the internal side of the inner casing. 
   Advantageously in this case, the ancillaries reception ducts open up onto the second sole plate which comprises ancillary fittings. 
   In the preferred embodiment of the invention, the outer casing comprises an ancillaries passage assembly. 
   Preferably, the ancillaries passage assembly comprises an attachment flange supporting a seal, and a seal support. 
   Also preferably, the seal is made of an elastomer material and comprises ancillary passage ducts. 
   Advantageously, the turbojet engine comprises an ancillaries protection arm mounted between the ancillaries passage assembly and the ancillaries distribution support. 
   The invention is particularly applicable to an outer casing that is the outer ring of the intermediate casing of a turbojet engine, and an inner casing that is the inner ring of the intermediate casing, but the applicant does not intend to limit the scope of his rights to this application. 
   The invention also relates to an ancillaries distribution support for the turbojet engine mentioned above as an intermediate product, comprising a first sole plate for reception of the ancillaries and a second sole plate for the distribution of ancillaries. 
   Preferably, the ancillaries reception sole plate comprises ancillary reception ducts. 
   Also preferably, metallic locking plates fixing the ancillaries in translation are arranged on the ancillary reception sole plate. 
   Advantageously, the ducts open up on the distribution sole plate, that comprises ancillary fittings at the ends of the ducts. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood after reading the following description of the preferred embodiment of the turbojet engine and the ancillaries distribution support according to the invention, with reference to the attached drawing on which: 
       FIG. 1  shows the partial diagrammatic perspective view of a turbojet engine according to prior art; 
       FIG. 2  shows a partial diagrammatic perspective view of the intermediate casing, in a preferred embodiment of the turbojet engine according to the invention; 
       FIG. 3  shows a partial diagrammatic perspective view of the outer ring of the intermediate casing with its flange, its elastomer seal and its seal support, in the preferred embodiment of the turbojet engine according to the invention; 
       FIG. 4  shows a diagrammatic perspective view of the flange and the elastomer seal of the preferred embodiment of the turbojet engine according to the invention; 
       FIG. 5  shows a diagrammatic perspective view of the seal support in the preferred embodiment of the turbojet engine according to the invention; 
       FIG. 6  shows a perspective diagrammatic view of the sole plate of the ancillaries support in the preferred embodiment of the ancillaries distribution support according to the invention; 
       FIG. 7  shows a partial diagrammatic perspective view of the preferred embodiment of the turbojet engine according to the invention, without its ancillaries protection arm; 
       FIG. 8  shows a partial diagrammatic perspective view of the preferred embodiment of the ancillaries distribution support according to the invention; 
       FIG. 9  shows a partial diagrammatic perspective view of the preferred embodiment of the turbojet engine according to the invention, with its ancillaries protection arm; 
       FIG. 10  shows a sectional diagrammatic view of the preferred embodiment of the ancillaries distribution support according to the invention, and 
       FIG. 11  shows a diagrammatic bottom view of the preferred embodiment of the ancillaries distribution support according to the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   With reference to  FIG. 2 , the turbojet engine  10  according to the invention comprises a casing called the intermediate casing, on the output side of the fan blades retention casing, through which the forward suspension of the turbojet engine  10  is traditionally fixed to an aircraft; the intermediate casing comprises an outer ring  11  supported by radial arms  12 , at the bottom of which an inner ring  34  extends on the output side, facing the outer ring  11 . 
   The invention is particularly applicable to routing of ancillaries along a radial arm  12  of the intermediate casing. 
   To facilitate differentiation between the elements, we will denote the outer ring  11  of the intermediate casing simply by the term “intermediate casing  11 ”, and the internal ring  34  of the intermediate casing simply by the term “ring  34 ”, in the following description. 
   A globally rectangular recess  13  is formed on the intermediate casing  11  facing the ring  34 , from the output edge  14  of the intermediate casing  11 . The intermediate casing  11  comprises a gutter  28  along the circumference of its output edge  14 . 
   With reference to  FIG. 3 , the recess  13  is arranged to hold an ancillaries passage assembly  53  comprising an attachment flange  14  supporting an ancillaries guide and flange seal  15 , and a part  16  that will be called the seal support  16 . 
   The various parts of the turbojet engine according to the invention will be described in the turbojet engine coordinate system in the remainder of this description. Thus, when a figure shows parts not installed on the turbojet engine, their various portions will be denoted as a function of their placement when they are installed. The various qualifications such as inner, outer, radial, axial, longitudinal, upstream, output, should be considered within the turbojet engine coordinate system, particularly as a function of its centreline. 
   With reference to  FIG. 4 , the flange  14  is globally in the form of a metallic yoke, comprising a base  17  and two branches  20 ,  20 ′ slightly curved to adapt to the form of the intermediate casing  11 . The base  17  of the flange  14  is arranged to bear on the upstream bottom  19  of the recess  13  of the intermediate casing  11 . It comprises a longitudinal step  18 , for which the projecting part is on the internal side of the base  17 . The step  18  is shaped to bear in contact on the inner face of the intermediate casing  11  on the upstream side of the recess  13 . 
   A seal  15 , in this case made of an elastomer material, is installed between the branches  20 ,  20 ′ of its outer side of the flange  14 , the outer surface of the seal being at the same level as the outer surface of the flange  14 . Several radial ancillary passage ducts  25  pass through the elastomer seal  15 . At its output end, the flange  14  comprises a longitudinal step  21 ,  21 ′ at each of its branches  20 ,  20 ′, located at a shorter distance from the outer surface of the flange than the distance from the opposite step  18 . 
   Two radial drillings  22 ,  22 ′ are made on the steps  21 ,  21 ′ facing the branches  20 , for reception of a screw. Two lugs  23 ,  23 ′ project on the lateral faces of the branches  20 ,  20 ′, on the upstream side of the steps  21 ,  21 ′. A radial drilling  24 ,  24 ′ is made in each lug. 
   With reference to  FIG. 5 , the seal support  16  is in the form of a metallic plate. On its output edge, it comprises two radial protrusions  26 ,  26 ′ forming a gutter  27 , arranged to achieve continuity of the gutter  28  of the intermediate casing  11 . 
   On its upstream edge, the seal support  16  comprises a central radial protrusion  29  comprising two longitudinal dogs  30 ,  30 ′ extending towards the upstream side, at its outer end. The upstream face  31  of the protrusion  29  and its dogs  30 ,  30 ′ are shaped to come into contact on the output face and the outer face of the elastomer seal  15 , respectively. 
   The seal support  16  also comprises two radial drillings  32 ,  32 ′ for reception of screws  33 ,  33 ′ on its upstream edge on each side of the central protrusion  29 , the radial drillings being separated from each other by the same distance as the drillings  22 ,  22 ′ in the flange  14 . 
   The assembly of the flange  14  on which the elastomer seal  15  and the seal support  16  is arranged in the recess  13 , is as follows. The flange  14  is installed in the recess  13  with its base  17  bearing in contact on the upstream bottom  19  of the recess  13  and its step  18  bearing in contact with the inner face of the intermediate casing  11  on the upstream side of the recess  13 . The lugs  23 ,  23 ′ are in contact with the inner face of the intermediate casing  11 , and are fixed to it by screws in their drillings  24 ,  24 ′. The seal support  16  is fixed to the flange  14  by screws  33 ,  33 ′ in the drillings  22 ,  22 ′ of the flange  14  through the drillings  32 ,  32 ′ in the seal support  16 . The upstream face  31  of the protrusion  29  and its dogs  30 ,  30 ′ then bear on the output face and the outer face of the elastomer seal  15  and there is continuity between the two. Furthermore in this configuration, the gutter  27  of the seal support  16  makes the gutter  28  of the intermediate casing  11  continuous. 
   Thus mounted, the flange  14 , the elastomer seal  15  and the seal support  16  assure continuity of the intermediate casing  11  while providing ancillaries passage ducts  25 . They form an ancillaries passage assembly  53  through which ancillaries pass through the intermediate casing  11 , while keeping them clamped in contact with each other, depending to the distribution of ducts  25  on the elastomer seal  15 . It also makes the assembly seal, the ancillaries being force fitted into their ducts  25 . 
   With reference to  FIGS. 6 and 7 , an ancillaries distribution support  35  is arranged on the ring  34  of the turbojet engine  10 , placed adjacent to the ancillaries passage assembly  53 . 
   The support  35  comprises a first sole plate on the outer side of the ring  34  for reception of ancillaries  38  projecting outside the ring. The sole plate  36  has a rounded triangular shape, the base of which is located on the upstream side of the ring  34  at the arm  12 , and the vertex is on the output side of the ring  34 . The width of the base corresponds approximately to the transverse width of the arm  12 . The first sole plate  36  comprises ancillary reception duct  37 , opening up on its outer surface. 
   Ancillaries  38 , originating from outside the intermediate casing  11 , are inserted in the ducts  25  of the elastomer seal  15 , extending along a radial support  39  parallel to the arm  12  installed between the intermediate casing  11  and the ring  34 , and their ends are force fitted into the ducts  37  of the sole plate  36 . 
   With reference to  FIG. 8 , the end of the ancillaries  38  comprises a special end piece composed of an annular seal  40  comprising an annular groove  41 . The seal  40  is adapted to its reception duct  37  and its force fitted such that its groove  41  is flush with the surface of the first sole plate  36 . Metallic plates  42  comprising adapted recesses  43  are fixed using screws  44  onto the sole plate  36 , their recesses  43  being on the grooves  41  of the seals  40  of the ancillaries  38  in order to block them in radial translation. 
   With reference to  FIG. 9 , an ancillaries protection arm  45  is fixed to the sole plate  36 , to the radial support  39 , to the flange  14  and to the seal support  16 . This arm  45  is in the form of a plate adapted to all elements to which it is fixed, to protect the assembly. Its section is globally constant and corresponds to the contour of the sole plate  36 . It is arranged to complete the shape of the arm in order to guide the secondary airflow passing between the intermediate casing  11  and the ring  34 . This shape is adapted to dynamic constraints imposed on the flow, and depends on parameters related mainly to fluid mechanics. 
   With reference to  FIGS. 10 and 11 , the ancillaries distribution support  35  comprises a second sole plate  46  on the inner side of the ring, located facing the first sole plate  36 . The reception ducts  37  of the ancillaries  38  pass through the first external sole plate  36  and prolong in the second distribution sole plate  46 . They may be oriented in the second distribution sole plate by an elbow  47 , so as to open up onto a lateral face of the second sole plate  46 , or they may not change direction and open up onto the inner face of the second sole plate  46 . They may also change diameter if required. 
   Ancillaries fittings  48  are arranged on the open end of the ducts  37 , on the second sole plate  46 . These fittings  48  comprise a fitting seal  49 , a nozzle  50  and an ancyllary screw-in nut  51 . Thus, ancillaries  52  fitted with specially arranged end pieces can be used to connect the ancillary fittings  48  to the second sole plate  46 . 
   The invention provides a solution to the crossing of the ancillaries  38  passing between the intermediate casing  11  and the ring  34 . The ancillaries  38  are inserted in the ducts  25  of the elastomer seal  15 , extending in the chamber formed by the arm  45  and the radial support  39  between the intermediate casing  11  and the ring  34 , and are inserted in the ducts  37  of the ancillaries distribution support  35 , through their end pieces  40  adapted to this purpose, at which they are blocked in radial translation by metallic plates  42 . The ducts  37  make the link with the ancillaries  52  inside the ring  34 , in other words the core of the turbojet engine  10 , that are connected to them by the fittings  48  of the distribution sole plate  46 . 
   The ducts  25  of the elastomer seal  15 , the ducts  37  of the ancillaries distribution support  35 , the metallic plates  42  and the fittings  48  of the second sole plate  46  are sized and shaped as a function of the ancillaries  38 ,  52  that they have to connect. Therefore, the invention provides a solution in which the ancillaries are assembled very simply in a standard manner. 
   Furthermore, particularly due to the fact that the ancillaries  38 ,  52  are no longer fixed by nuts on each side of the ring  34  and instead are force fitted into the ducts  37  or end pieces  48 , a large amount of space is saved for their connection, resulting in an ancillaries distribution support  35  in which the longitudinal surface does not extend beyond the surface of the ring  34 . Therefore, there is no longer any need to form a recess in the cowls of the internal secondary flow casing, since the arm  45  adjacent to the ancillaries distribution support  35 , and particularly its first sole plate  36 , does not occupy any of the opening and closing areas. 
   The ancillaries distribution support  35  may indifferently be formed from a single piece with the ring  34  or it may be added onto the ring.