Abstract:
The disclosed subject matter relates to a hydraulic and electrical interface ring for a turbine engine, characterized in that said ring comprises fluid transfer pipes which axially pass therethrough and having axial ends that form axial interlocking means, the supporting means of at least one electrical device, and at least one electrical linking connector of the device, said connector being configured to engage by axial interlocking with a complementary electrical connector of another part.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a hydraulic and electrical interface ring for a turbine engine, which is particularly suitable but not exclusively for supplying fluid (such as oil) to an open-rotor type linear turbine engine actuator. 
       PRIOR ART 
       [0002]    An open-rotor type turbine engine mainly comprises, along a longitudinal axis and inside a cylindrical nacelle, supported by the structure of the aircraft (such as the rear portion of the fuselage of an aeroplane), a “gas generator” part and a “thruster” part (only the nacelle part covering the gas generator is fixed, whereas the nacelle parts in which the rotating casings are accommodated are rotational). The thruster part comprises two coaxial and counter-rotating propellers, which are upstream (front) and downstream (rear) respectively and comprise rotational casings having polygonal rings, and which propellers are set into opposite rotation from one another, for example, by a suitable mechanism which is driven by a power turbine which is located at the output of the gas generator part, the blades of the propellers extending radially outside the nacelle. 
         [0003]    To allow optimum operation of the turbine engine in the various flight phases encountered, the blades of the counter-rotating propellers can rotate in the radial compartments of the rings. For this purpose, they are set into rotation about their respective pivot axes, by a suitable orientation system for varying the pitch of the blades during flight, that is to say the pitch of the propellers. For example, the blades can vary according to the system, from +90° to 30° for the flight phases, from +30° to −30° for the ground and thrust reversal phases, and can have a rapid return to 90°, in the feathered position, in the event of a malfunction in flight, for which the blades are retracted relative to the direction of travel of the aeroplane and cause as little drag as possible. 
         [0004]    As a system for orienting the blades, that described in the French patent application of the applicant FR 11 58891 is known. 
         [0005]    This system for orienting the blades of a propeller comprises:
       a fluid power control mechanism having a linear actuator which is centred on the longitudinal axis of the turbine engine and is rigidly connected to a fixed casing supporting the propeller;   a connection mechanism for transforming the translation of the movable part of the actuator into a rotation of the blades in order to modify the pitch thereof, and comprising, for this purpose, a transfer bearing, the inner ring of which is rigidly connected to the movable part of the actuator, and a transmission means having connecting rods between the outer ring of the bearing and the blades, and   a means for lubricating said transfer bearing.       
 
         [0009]    As soon as the movable part of the actuator moves, the inner ring of the transfer bearing, which is rigidly connected to the movable part of the actuator, follows the movement and drives the rotational outer ring via the contact of the running gears, and pulls or pushes on the connecting rods of the transmission means, thereby making it possible to modify the pitch angle of the blades which rotate in their compartments. 
         [0010]    The lubrication means ensures the continuous lubrication and cooling of the bearing, irrespective of the axial position of the actuator. 
         [0011]    A technique allowing optimum lubrication of the bearing, which was developed by the applicant, was the subject matter of FR 12 56140 and consists in channelling the lubricating oil as far as the inside of the bearing, passing through the actuator. 
         [0012]    In particular, fixed rods or pipes are connected to a source of lubricant in order to interact in a sliding manner with the movable part of the actuator (through passages made in the movable part, through the inside of the anti-rotation rods provided between the movable and fixed parts of the actuator, or through an annular cavity located between the movable part of the actuator and a support of the inner ring of the bearing) and to inject the lubricant coming from the transportation rods thereof into radial holes in the inner ring as far as the inside of the bearing. 
         [0013]    The actuator has to be supplied with pressurised or actuating oil in order to ensure the operation thereof, that is to say to supply the chambers thereof with high-pressure oil and to cause the sliding of the movable part thereof on the fixed part thereof, as described in FR 12 56923. The fixed part of the actuator is rigidly connected to a fixed cylindrical structural casing by means of an annular collar, the sources of pressurised oil being located in front of and inside the casing. However, the movable part of the actuator, which is mounted around the fixed part and connected, by the bearing, to the blades of the propeller in question via a linkage system, is located on the rear, outer side of the collar, opposite the front, inner side of the collar, on which side power supplied towards the actuator arrives. The problem therefore arises of transferring actuating oil through the separating collar, in the present case, from the inside to the outside thereof. 
         [0014]    The aim of the present invention is to provide a solution to this problem by designing a fluid-transfer device thus acting as an interface in particular between an upstream supply and a downstream member intended for receiving the fluid, said fluid being for example lubricating oil and/or actuating oil. 
       SUMMARY OF THE INVENTION 
       [0015]    For this purpose, the invention proposes a hydraulic and electrical interface ring for a turbine engine, characterised in that it comprises ducts for transferring fluid passing axially through the ring, and the axial ends of which form axial interlocking means, the ring further comprising means for supporting at least one electrical equipment, and at least one connector for electrically connecting the equipment, said connector being designed to interact by means of axial interlocking with an electrical connector which is complementary to another part. 
         [0016]    The invention is particularly advantageous because it makes it possible to integrate a plurality of functions or pieces of ancillary equipment in one and the same part, that is to say the ring, said ring being used to transfer fluid, such as oil, but also to support at least one (piece of) electrical equipment and the electrical connection means thereof. In addition, said ring is designed to facilitate the mounting thereof by means of axial interlocking on another part, for example in a blind manner, as will be described in detail below. The manufacture of said other part can also be simplified thereby. 
         [0017]    In the present application, interlocking means is understood to mean means which are designed to engage in an interlocking manner in complementary means of another part or to receive in an interlocking manner complementary means of another part. The interlocking means are therefore of the male or female type. 
         [0018]    In addition, hydraulic or electrical interface element is understood to mean an element which is capable of transferring or distributing a fluid such as oil from at least one first part to at least one second part, and of ensuring a connection or electrical connection between at least one first part and at least one second part, the electrically connected parts not necessarily being parts which are intended to provide and receive fluid. The element may be inserted between two of said parts. In the present invention, the ring is a hydraulic and electrical interface element which provides a transfer of fluid and an electrical connection. 
         [0019]    Electrical equipment is understood to mean an equipment or a piece of equipment which is powered by electricity, which provides electrical power and/or which is designed to provide an electrical connection. Said (piece of) equipment may be an electric sensor, such as a position sensor, or merely an electrical conductor. 
         [0020]    In the present application, the term electrical connector is used to refer to either a socket or a plug, the socket being intended to interact in an interlocking manner with a plug in order to provide an electrical connection. 
         [0021]    The ring preferably comprises means for fastening to the other part. The ring comprises for example axial holes for the passage of screws which are intended to be screwed into nuts of the part. 
         [0022]    The equipment supported by the ring is for example an axial position sensor, for example of the LVDT (linear variable differential transformer) type. The ring may thus comprise means for supporting at least one sensor of this type. These support means are preferably articulated to one end of the sensor by means of a ball-joint connection. 
         [0023]    At least one of the ends of each duct is preferably tubular and projects axially on the ring. Said tubular ends form protrusions on the ring which form said interlocking means. 
         [0024]    The present invention also relates to an assembly comprising a ring as described above and an annular collar, characterised in that the collar comprises a cylindrical bearing surface for centring the ring and an annular face for axially supporting the ring, an electrical connector being designed to interact by axial interlocking with the connector of the ring when the ring is axially supported on the collar, and longitudinal channels for circulating fluid, which each have a longitudinal end which is opposite an end of a duct of the ring and is intended to be connected to said end, for example by means of a fluid or hydraulic connection. Said connection may be associated with a swivel connection at each of the axial ends thereof. 
         [0025]    Advantageously, the ring and the cylindrical bearing surface for centring the collar are designed to interact by means of sliding adjustment, that is to say with play, thereby making it possible to facilitate the mounting of the ring and to allow the dismounting thereof. 
         [0026]    The collar may comprise holes in which nuts or inserts are accommodated. As indicated above, the ring may comprise axial holes for the passage of screws which are intended to be screwed into said nuts or inserts. 
         [0027]    In a particular embodiment of the invention, a cavity for receiving fluid is made between the collar and the ring, said cavity being connected to the longitudinal ends of the channels in the collar and the ends of the ducts of the ring. The receiving cavity makes it possible to distribute the fluid from the collar towards the ring. Said receiving cavity may comprise a circular groove which is made in the collar and a circular groove which is made in the ring. Each of these grooves may extend over part of the circumference of the ring or of the collar. 
         [0028]    The longitudinal channels in the collar may comprise pipes which are attached to the collar or may be formed in bosses on the collar. 
         [0029]    The present invention also relates to a turbine engine module, comprising an assembly of the above-mentioned type which is mounted at an axial end of a linear actuator, said actuator comprising a fixed inner part and an outer part which can move in axial translation on the fixed part, the movable part defining chambers around the fixed part, at least one of said chambers being supplied with fluid by means of rods of which the axial ends opposite the actuator are designed to be interlocked in the ducts of the ring. The rods are preferably axial and telescopic. They may be associated with a swivel connection at each of the axial ends thereof. 
         [0030]    The movable part of the actuator can be fastened to an end of at least one axial position sensor, for example of the LVDT type, the opposite end of which is fastened to the interface ring. Said sensor makes it possible to recognise in real time the axial position of the movable part of the actuator (and thus the pitch of the blades of the propeller when the actuator is used to orientate the blades of the propeller). In the case of an LVDT sensor, the transformer of said sensor can be located on the side of the ring and fastened thereto. Said transformer is connected to an electric cable which can thus be connected to the connector of the ring. 
         [0031]    The present invention lastly relates to a method for mounting a module as described above, characterised in that said method comprises the steps consisting in:
       assembling the actuator and mounting the ring at an axial end of the actuator in such a way that the axial ends of the rods which are opposite the actuator are interlocked in the ducts of the ring,   moving the actuator and the ring in axial translation towards the collar until the ring is axially supported on the collar, the ducts of the ring are in fluid communication with the channels in the collar, and the connector of the ring is interlocked in the connector of the collar, and   fastening the ring to the collar.       
 
         [0035]    The method can additionally comprise one or more of the steps consisting in:
       tightening fastening flanges of the collar and of the actuator, and   pre-assembling a transfer bearing and transmission means of a system for orienting the blades of a propeller, before mounting the assembly on the actuator.       
 
         [0038]    Mounting the actuator and the ring on the collar can be carried out in a blind manner, that is to say without seeing said collar. The pre-mounting of the ring on the actuator makes it possible to rigidify the ancillary equipment (for example telescopic rods, LVDT sensors, etc.) between said parts during mounting and to simplify the mounting. As explained above, said mounting is relatively simple because it is sufficient for the elements of the ring to be interlocked in complementary elements of the collar to produce the assembly. The interlocking means of the ring and/or of the collar can form foolproofing means which allow correct angular positioning of the parts relative to one another. Another advantage is that the ring makes it possible to avoid carrying out complex machining operations on the collar and to transfer these operations to the ring, which has a simpler shape and smaller dimensions. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0039]    The invention will be better understood and other details, advantages and features of the invention will become apparent by reading the following description given by way of non-limiting example, with reference to the accompanying drawings, in which: 
           [0040]      FIG. 1  is a schematic perspective view of the hydraulic and electrical interface ring according to the invention, 
           [0041]      FIG. 2  is a schematic perspective view of an electrical sensor of the LVDT for the ring from  FIG. 1 , and of the support means thereof, 
           [0042]      FIGS. 3 and 4  are schematic perspective views of an annular collar of an assembly according to the invention, seen from upstream and from downstream respectively, 
           [0043]      FIGS. 5 and 6  are schematic perspective and axial cross-sectional views of the assembly comprising the ring from  FIGS. 1 and 2  and the collar from  FIGS. 3 and 4 , 
           [0044]      FIG. 7  is a very schematic view of a system for orienting the pitch of the blades of a turbine engine propeller, comprising a linear actuator and an assembly according to  FIGS. 5 and 6  which is mounted upstream of said actuator, 
           [0045]      FIG. 8  is a partial perspective view of the collar and of the ring according to a variant of the invention, 
           [0046]      FIG. 9  is a partial perspective and axial cross-sectional view of the ring and of the collar from  FIG. 8 , and 
           [0047]      FIG. 10  is a partial perspective view of the collar from  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION 
       [0048]    In the following description, the terms “upstream” and “downstream” refer to the direction of flow of the gases in a turbine engine. 
         [0049]      FIGS. 1 to 6  show an embodiment of an assembly  10  according to the invention, said assembly  10  which is visible in  FIGS. 5 and 6  essentially comprising two members; a hydraulic and electrical interface ring  12  shown in  FIG. 1  and an annular collar  14  shown in  FIGS. 3 and 4 . As will be described in greater detail below with reference to  FIG. 7 , said assembly  10  can be used to supply oil to a linear actuator  16  for setting the pitch of the blades  18  of an open-rotor type turbine engine propeller. 
         [0050]    The ring  12  having an axis of rotation A comprises tubular ducts  20  for transferring oil, means  22  for supporting LVDT sensors  24 , a connector  26  for electrical connection of said sensors  24 , and means  28  for fastening to the collar  14 . 
         [0051]    The ducts  20  are substantially parallel to one another and to the axis A, and there are at least four thereof in the example shown. Said ducts  20  pass axially through the ring  12  and the rear or downstream ends thereof are defined by cylindrical end fittings  30  which project axially on a downstream radial face  32  of the ring. Each end of each of the ducts  20  is designed in this case to receive a fluid connection by interlocking, which connection may be merely a bushing or a telescopic tubular rod, as will be described in greater detail below. 
         [0052]      FIG. 2  shows on a larger scale the means  22  for supporting an LVDT sensor  24  and said LVDT sensor. 
         [0053]    In a known manner, an LVDT sensor  24  comprises a ferromagnetic core which is mounted in an axially sliding manner inside a cylinder  34  comprising a transformer. The movement of the core leads to a modification of the distribution of the magnetic fields inside the transformer. The distribution of the fields thus depends on the axial position of the core in the transformer. This type of sensor can thus be used to determine the axial position of an integral part of the core of the sensor, relative to another integral part of the cylinder of the sensor. 
         [0054]    The support means  22  from  FIG. 2  comprise a socket  36 , one end of which is connected to a plate  38  for fastening to the ring  12 , and the other end of which comprises a yoke  40  for articulation on an end of the cylinder  34  of an LVDT sensor. 
         [0055]    The plate  38  is applied to an upstream boss (which could be used to mount another type of electrical equipment) on the ring  12  and is fastened to the ring by screws which pass through holes  42  in the plate and are screwed into inserts  43  which are accommodated in blind holes in the boss on the ring. The yoke  40  is preferably articulated on the end of the cylinder  34  by a ball-joint connection. 
         [0056]    In the mounting position, the longitudinal axes of the cylinders  34  of the sensors  24  are parallel to one another and to the axis A. The sensors  24  are located on the same (downstream) side as the end fittings  30  of the ducts  20 . 
         [0057]    The sensors  24 , and in particular the transformers of the cylinders  34 , are connected to the electrical connector  26  by electric cables, which are shown schematically by dotted lines  44  in  FIG. 1 . Said cables  44  preferably all pass in the same direction around the ring  12  as far as the connector  26  and merge with one another as soon as possible. 
         [0058]    The connector  26  comprises for example a (male or female) plug which is mounted in an axial hole  46  in the ring and is intended to interact with a (female or male) complementary socket of a connector which is mounted in an axial hole  48  in the collar ( FIG. 6 , the socket not being shown for the sake of clarity). 
         [0059]    The fastening means  28  of the ring  12  in this case have an annular row of tabs  50  which extend radially towards the outside from the outer periphery of the ring. Said tabs  50  comprise axial holes  52  for the passage of screws  54  which are intended to be screwed into nuts which are supported by the collar  14 . Said holes  54  can be used to fasten clamps for holding the electric cables  44 . 
         [0060]    The collar  14  has a generally frustoconical shape, the end thereof having a smaller diameter being located downstream. The ring  12  is intended to be mounted on said downstream end which comprises a downstream radial face  56  for axially supporting the ring and a cylindrical bearing surface  58  for centring the ring during the mounting thereof. 
         [0061]    The ring  12  comprises a cylindrical edge  60  on the outer periphery thereof which faces upstream and the free upstream end of which is intended to be axially supported by the face  56  of the collar  14 . The ring  12  further comprises a cylindrical edge  62  on the inner periphery thereof which faces upstream and the inner surface of which interacts in a sliding manner with the bearing surface  58  of the collar  14  during the mounting of the ring ( FIGS. 4 and 5 ). Due to the presence of said two respectively radially outer and inner cylindrical edges  60  and  62 , the ring  12  has a substantially U-shaped cross section, the opening of which faces axially upstream, the edges  60  and  62  defining an annular groove therebetween which is closed in the upstream direction by the collar  14 . 
         [0062]    The collar  14  also has an annular row of holes  63  in which nuts (not shown in the drawings) are fixed for screwing the screws  54  for fastening the ring  12 . In a variant, the collar could comprise bosses in which blind holes would be formed to accommodate inserts for screwing the screws  54 , said inserts being for example similar to the inserts  43  mentioned above. 
         [0063]    The collar further comprises, at each of the axial ends thereof, an annular fastening flange  64 ,  66  comprising holes for the passage of screw-nut type means. 
         [0064]    The collar  14  also comprises longitudinal channels  68  for circulating oil, substantially from the upstream flange  64  as far as the radial face  56 . There are four of said channels  68  in the example shown and said channels are formed in longitudinal bosses  70  which project on the inner frustoconical surface of the collar  14  ( FIGS. 3 and 5 ). Due to the frustoconical shape of the collar  14 , the upstream ends  72  of the channels  68  (forming oil inlets), which are located on a circumference having a diameter which is greater than that of the circumference on which the downstream ends  74  of the channels (which form oil outlets) are located. 
         [0065]    The upstream end  72  of each channel  68  receives in an interlocking manner an axial end of a tubular hydraulic connection  76 . The downstream end  74  of each channel  68  receives in an interlocking manner an axial end of another tubular hydraulic connection  78 , the opposite axial end of which is interlocked in the upstream end of a duct  20  of the ring  12 . In this case, the connections  76 ,  78  are in the form of bushings. Each connection  76 ,  78  may comprise a sealing joint at each of the axial ends thereof and an outer annular flange for axial support on the collar  14 . Preferably, the connections  76 ,  78  each have a passage cross section which is substantially the same as that of the end fitting  30  and of the duct  68  which are associated with said connection. The use of a connection  78  instead of an end fitting which is produced directly on the ring  12  has the advantage of facilitating the manufacture of the ring and of reducing the geometric constraints of the assembly. 
         [0066]    As explained above, the assembly  10  formed by the ring  12  and the collar  14  can be used for supplying oil to a linear actuator  16  for orienting the pitch of the blades  18  of an open-rotor type turbine engine propeller ( FIG. 7 ). 
         [0067]    The blades  18  of the propeller are of the variable-pitch type, that is to say that they can be orientated around the radial axes thereof by means of a system for controllably orienting the pitch of the blades, in such a way that they occupy a desired optimum angular position according to the operating conditions of the turbine engine and the flight phases in question (rotation of the blades in both directions with increasing and decreasing propeller angles, and return of the blades to the feathered position in the event of malfunction). 
         [0068]    The system for orienting the blades  18  of the propeller comprises the linear movement actuator  16  which is centred on the axis A, a bearing  80  for transferring movement, and transmission means  82  for providing the angular rotation of the blades. 
         [0069]    The actuator  16  is annular and comprises a cylindrical fixed part  84 , the upstream end of which comprises an annular flange  86  for fastening to the downstream flange  66  of the collar  14 . Around the fixed part  84  is located an annular part  88  which can move in an axially sliding manner on the fixed part  84 . 
         [0070]    The movable part  88  defines two annular chambers  90 ,  92  around the fixed part  84 , which chambers are upstream and downstream respectively and are filled with oil and are connected to means for supplying oil and discharging oil. For example, supplying oil to the upstream chamber  90  leads to an increase in the volume thereof and to a movement of the movable part  88  upstream. 
         [0071]    The transfer bearing  80  is mounted on the movable part  88  of the actuator, the bearing  80  in this case being a double-row ball bearing, the inner ring of which is fastened to the movable part  88  in that it is connected thereto for conjoint translational movement, and the outer ring is connected to the blades  18  by the transmission means  82 . 
         [0072]    Said transmission means  82  comprise for example connecting rods  36 . As the movable part  88  moves axially (in one direction or the other), the inner ring of the bearing  80 , which is rigidly connected to the movable part, drives the outer ring by contacting the balls, and pulls on the connecting rods, making it possible to modify the pitch angle of the blades  18 . 
         [0073]    The assembly  10  described above can be used in particular for transferring oil from an upstream source (arrow  94 ) as far as at least one of the chambers  90 ,  92  of the actuator  16  and the bearing  80  for the lubrication thereof. For this purpose, telescopic tubular rods  96  for fluid connection (shown schematically by dotted lines) extend parallel to the axis A and have downstream ends in fluid communication with the chamber  90  for example or means for lubricating the bearing  80 , and upstream ends which are interlocked in the above-mentioned tubular end fittings  30  of the ducts  20  of the ring. The number of rods  96  is equal to the number of ducts  20  of the ring  12  and there are therefore four thereof in the example shown; two for supplying oil to the chamber  90  and two for lubricating the bearing  80  for example. Preferably, the upstream end of each rod  96  is interlocked in an end fitting  30  by means of a swivel connection. Each duct  20  may comprise an inner thread for screwing a nut for fastening a telescopic rod  96 . 
         [0074]    Thus, the oil which penetrates the channels  68  in the collar  14  flows downstream and into the ducts  20  of the ring, then into the telescopic rods  96  so as to be transported as far as the chamber  90  and the bearing  80 . 
         [0075]    The reference sign  98  denotes a ferromagnetic core of one of the LVDT sensors  24 , said core extending parallel to the axis A and being fastened to the movable part  88 , preferably by a swivel connection. The core  98  is mounted in a sliding manner in one of the cylinders  34  which are supported by the ring  12 , as described above. 
         [0076]    The swivel connections for fastening the sensors  24  and the telescopic rods  96  make it possible to compensate any possible misalignments between the parts on which they are fastened, in order to avoid bowing thereof. 
         [0077]    The assembly  10  and the actuator  16  form a turbine engine module which can be assembled in the following manner:
       during a first step, the actuator  16  is assembled and the ring  12  is mounted upstream of the actuator in such a way that the axial ends of the ends of the telescopic rods  96  which are opposite the actuator are interlocked in the end fittings  30  of the ducts  20  of the ring,   the actuator and the ring are then positioned angularly around the axis A in such a way that, in particular, the connector  26  of the ring is aligned axially with that of the collar  14  (the ring can be equipped with foolproofing means which are intended to interact with complementary means of the collar so as to facilitate said positioning), the actuator and the ring are then moved in axial translation towards the collar  14  until the ring is axially supported on the collar, the connections  78  which were previously mounted on the collar then interlock in the ducts  20  of the ring, and the connector  26  of the ring interlocks in that of the collar,   the ring and the collar are then fastened together by tightening the screws  54 ; the tightening of the screws  54  provides the locking of the module and the electrical connection between the connectors of the ring and of the collar,   the flanges  66  and  86  are pressed against one another, and   the bearing  80  and the transmission means  82  are pre-assembled and can then be mounted on the actuator  16 .       
 
         [0083]    Said assembly can be produced vertically, during mounting, by the engine being oriented so that the axis A is vertical. 
         [0084]      FIGS. 8 to 10  show a variant of the invention in which the ring  112  is intended to collect the lubricant coming from the collar  114  and transfer it to telescopic rods  196  to supply the actuator (not shown). 
         [0085]    In order to provide such a transfer, the ring  112  is attached axially to the downstream or rear side of the collar  114 , rotated externally towards the actuator, relative to the flow passing through the engine of the turbine engine, by making, between the ring  112  and the collar  114 , a sealed cavity  100  for receiving the lubricant, connecting the input and output supplies, as will be seen later. 
         [0086]    Close to the outer flange  164 , on the side of the front or upstream face of the collar  114 , there is located a support  102  which is arranged on a retaining tab  104  of the collar to receive the end of a pipe  168 , the other end of which engages, in a sealing manner, in the hole  106  of a boss  170  which is close to the inner flange  166 . Thus, the pipe  168  radially follows the frustoconical wall of the collar, extending along the front face thereof. In the end of the pipe  168 , which is connected to the support  102 , the input supply of lubricant is connected in a sealing manner. In the bottom of the boss  170 , an axial through-hole  108  is pierced in the thickness of the wall of the collar, and opens into the inner cavity  100  in the ring, in such a way as to lead the oil into the cavity. The hole  108  is pierced from the rear side of the collar so as to open into the bottom of the hole  106  in the boss  170 , the wall of which prevents piercing from the front side of the collar. 
         [0087]    In the embodiment shown, the ring  112  is mounted concentrically in an annular support part  158  forming a receiving compartment for the ring and issuing axially from the wall of the collar. In order to ensure the placement and centring thereof, the ring also has an annular projection  171  which engages in a complementary receiving cutout  172  made in the collar. This takes place until the front transverse face  173  of the wall  176  of the ring  112  interacts with the rear face  174  of the wall of the collar, and, between said faces, the annular cavity  100  is provided, which extends substantially over half the circumference. The ring  112  is thus in axial abutment against the collar  114 . 
         [0088]    The cavity  100  is obtained in this case by a substantially semi-circular groove  175  which is made in the wall  176  of the front face  173  of the ring and by a corresponding groove  177  which is made in the wall of the rear face of the collar. The two joined grooves  175 ,  177  thus form the cavity  100  and the through-hole  106  communicating with the pipe  168  for the inflow of the lubricant opens in the bottom of the groove of the collar, as shown in  FIG. 8 . The sealing of the cavity  100  between the ring  112  and the collar  114  can be produced by the direct surface contact of the opposing faces  173 ,  174  thereof, in particular due to the fact that the lubricating oil pressure is relatively reduced, or, in a variant, by one or more joints (not shown). 
         [0089]    The axial pressing of the ring  112  against the collar  114  is obtained by a retaining nut  178  which is screwed into a thread of the support part  158  of the collar which is used for the centring, and which is applied against the rear outer face  179  of the ring, pressing said face against the collar. 
         [0090]    In addition, in order to provide a single possible assembly position during the mounting of the ring on the collar, ensuring in particular that the grooves  175 ,  177  correspond, a foolproofing means is provided, which additionally interconnects the collar and the ring for conjoint rotation. Although it is not shown, said means can comprise a specific male-female assembly (such as teeth and hollows provided in the ring and the collar) allowing the connection in rotation and the interaction of said teeth and hollows in a single position). 
         [0091]    As shown in  FIG. 9 , in the bottom of the semi-circular groove  175  of the ring are provided, in this example, two through-holes  180  which are substantially located at the ends of said groove, that is to say in diametrically opposite positions. 
         [0092]    Hydraulic connections or connectors  181  are engaged in said holes  180  for the connection between the cavity  100  and the telescopic rods  196 , as shown in particular in  FIG. 9 . 
         [0093]    The other ends of the rods  196 , which are opposite those which are connected to the connectors  181 , can each have a profile which makes it possible to receive a joint or the like to facilitate the sliding with the cavity to be supplied in the movable part of the actuator during movement. The joint cannot avoid potential misalignments but, by contrast, it advantageously compensates them by introducing a ball-joint function between the rod for injecting the lubricant and the channel to be supplied whilst preserving the sealing between the rod and the channel in the event of small misalignments therebetween. 
         [0094]    Providing two (or more) diametrically opposite holes  180  in the ring  112 , to which holes the rods  196  are connected, makes it possible to advantageously distribute the lubricant in a uniform manner in the bearing. Carrying out a supply at a plurality of points on the ring in order to supply a plurality of rods and, thus, a plurality of channels, from a single common supply source is one of the major advantages of the invention. 
         [0095]    In the front transverse face  173  of the ring  112 , a curved groove can be made, substantially on the remaining part of the ring where the semi-circular groove  175  for the lubricant is absent. Said curved groove substantially follows the lubricant groove  175 , by being approximately in the circular extension thereof, and can define an arc of less than 180°. Of course, said arc could take any other value according to requirements. At the centre of the groove, a site can be provided for receiving and fastening an electrical connector. 
         [0096]    The rear transverse face  179  of the ring  112  can comprise sites (compartments or holes) for receiving sensors and telescopic rods  196  respectively. Said sites face the control mechanism of the actuator and are arranged in such a way that the rods are opposite the receiving cavity of the actuator, leading to the bearing to be lubricated, and that the coaxiality of the parts of the sensors is ensured. With regard to the collar  114 , said collar may have, opposite the connector which is fastened to the ring  112 , a cutout which is made in the transverse wall thereof, in such a way as to be able to connect to the connector, which is fastened to the distribution ring, a cable which is equipped with a suitable complementary connector. 
         [0097]    Therefore, the invention not only makes it possible to transfer, from the inside of the collar  114  (from a single supply) to the outside thereof (through a plurality of outlets), and completely reliably, lubricant towards the bearing of the system for orienting the blades of the propeller in question, and high pressure lubricant towards the actuator through input supplies inside the casing of the turbine engine, but also to provide instrumentation support for sensors, making it possible to advantageously connect said sensors via a single connector to an electrical power supply coming from the inside of the casing.