Abstract: Method for forming a protective layer on a metallic turbine substrate, comprising the steps of: preparing an aqueous solution comprising a first component comprising a soluble salt or alkoxide; dissolving in the solution a second component based on an organic substance comprising a carbonyl group or an amine group; bringing the solution into contact with the metallic substrate; and heating the metallic substrate to a temperature in the range from 300° C. to 800° C. to form a layer of oxide on the metallic substrate. The first component is preferably a nitrate. The second component is preferably selected from the group consisting of urea, amino-acids, organic acids, hydrazine and its derivatives, azine and its derivatives, amines and mixtures of these.

Abstract: A transmission gearbox (1) has a casing (2) that tilts around a tilting axis (B—B) via two bearings (19). Each of the bearings includes: a fixed part (20) having a sleeve (20a); and a trunnion (21a) which belongs to a pivoting part (21) and which pivots around the sleeve, the pivoting part being solidly connected to the casing (2). A shouldered wear ring (22) is disposed between the sleeve (20a) and the trunnion (21a) of each bearing (19). The invention is suitable for use in the pivot mounting of a power transmission gearbox (1) that is used to rotate the tilting rotor (14) of a convertible aircraft.

Abstract: An installation includes at least a pressurized lubricating circuit for elements housed in the rocking crankcase, each circuit including a radial transfer bearing between two opposite cylindrical journals coaxial about the rocking axis, one fixed journal on a fixed part and one pivoting journal on a pivoting part integral with the pivoting crankcase. Each transfer bearing has two U-shaped annular gaskets facing each other and spaced apart along the rocking axis so as to define between them an annular pressurized liquid lubricant chamber. The annular chamber is supplied with pressurized liquid lubricant by at least a supply duct integrated in the fixed part and whose upstream part is connected to a pressurized lubricant source, and feeds the rocking crankcase with pressurized lubricant through a dispensing duct emerging into the rocking crankcase. The invention is useful for lubricating rocking power transmission boxes for convertible aircraft tilt rotors.

Abstract: Mechanical transmission for aeronautical applications, in which a kinematic chain housed inside a leakproof casing has a main power input shaft actuated by a thermal propulsion unit and a secondary power input shaft which can be actuated externally by means of a rotating head which can be coupled to the secondary shaft in a releasable manner by means of a magnetic assembly so as to allow rotation of the secondary shaft at low speed and when the main propulsion unit is inactive.

Abstract: The invention provides a system for passively controlling pressure oscillations of hydrodynamic origin in a solid propellant thruster comprising a body containing a charge of solid propellant, the system comprising at least one insert disposed in the thruster body transversely relative to the flow direction of the combustion gases of the solid propellant. The insert has an opening of non-axisymmetric shape so as to generate a three-dimensional effect on the flow and prevent axisymmetric turbulent modes from forming in the thruster. Thus, the control system of the invention serves to break the symmetry of the flow and thus prevents axisymmetric turbulence forming which is the source of instability that the present invention seeks to control. The present system is applicable to existing thrusters.

Abstract: A blade for a stator of a variable-geometry turbine, particularly for aircraft engines; the blade has an airfoil profile hinged to a structure of the stator to rotate about an axis, and having a pressure front wall and a suction rear wall; the blade also has two end walls, which are located at opposite ends of the airfoil profile, cooperate in sliding manner with the structure of the stator, and are cooled, in use, by air flowing through a number of holes; the outlets of the holes are located close to the outer edges between the end walls and the front wall to generate a tangential stream of cooling air by virtue of the pressure difference acting on the front and rear walls.

Abstract: 14A method of producing a bearing housing from a worn housing extending along an axis and having an intermediate portion; four end portions located at opposite axial ends of the intermediate portion; and an inner shield, the ends of which are integral with the intermediate portion and one end portion. According to the method, the intermediate portion and the shield are detached from the end portions and replaced with a new shield and a new intermediate portion, whereas the end portions are used again; and, to weld the new intermediate portion to the salvaged end portions, a fixture is provided for ensuring the necessary parallelism, squareness, flatness, concentricity, and dimensions of the portions.

Abstract: An axial turbine for aeronautical applications has a casing housing a stator, which is provided with an array of airfoil profiles, which are positioned angularly equidistant from one other about the axis of the turbine, define associated spaces between one another for the passage of a flow of gas and are hinged to an annular structure, each one about an associated hinge axis incident to the axis of the turbine; in service, the airfoil profiles are simultaneously actuated to rotate by an identical angle of adjustment by means of a ring actuated by actuators outside the casing and connected to each airfoil profile via an associated lever.

Abstract: A method of producing and assembling a cooling device inside an axial-flow gas turbine blade; the airfoil profile of the blade has an inner surface defining a chamber, and is connected to a supporting structure by two opposite end pins having respective openings for the passage of cooling air and which come out inside the chamber; the method provides for forming an insert having a number of holes and defined by a first and at least a second body separate from each other, and each of a size approximating but no larger than that of at least one of the openings; the bodies are inserted successively through the openings in the pins, and are positioned inside the chamber to direct a relative stream of air through each hole on to the inner surface of the airfoil profile.

Abstract: A hinge device for a rotary member of an aircraft engine having a conduit housing the rotary member and for conducting a stream of gas, and a cavity outside the conduit and for receiving a mass of air having, in use, a higher pressure than the conduit; the device having a seat formed in a platform interposed between the cavity and the conduit, and a pin integral with the rotary member and engaging the seat to rotate about an axis; the pin is cooled by a stream of air, which flows inside a passage having an inlet which comes out inside the cavity, an outlet which comes out inside the conduit, and at least one number of channels formed outside the pin and spaced angularly apart; and part of the passage is formed on a collar portion fitted to the pin to calibrate the flow of air inside the passage.

Abstract: A blade for a stator of a variable-geometry turbine, particularly for aircraft engines; the blade has an airfoil profile hinged to a structure of the stator to rotate about an axis, and having a pressure front wall and a suction rear wall; the blade also has two end walls, which are located at opposite ends of the airfoil profile, cooperate in sliding manner with the structure of the stator, and are cooled, in use, by air flowing through a number of holes; the outlets of the holes are located close to the outer edges between the end walls and the front wall to generate a tangential stream of cooling air by virtue of the pressure difference acting on the front and rear walls.

Abstract: A vane for a stator of a variable-geometry turbine, in particular for aeronautical engines, has an airfoil profile and a pair of hinge portions, which are carried by the airfoil profile and enable the airfoil profile to be coupled to a support structure of the stator so as to be rotatable about an axis of adjustment; the vane also has internal channels that allow a flow of air to pass through in order to cool the hinge portions.

Abstract: A speed reducer has a sun gear for connection to a turbine of an engine and a planet carrier supporting a number of planetary gears meshing with the sun gear and with the ring gear fitted to the engine mounting. According to the present invention, the planet carrier has a first annular element having pairs of seats for pins on each of which rotates one of the planetary gears. A second annular element for connection to a compressor of the engine has a number of axial arms fitted inside respective cavities of the first annular element. An end of each axial arm is connected to a portion of the first annular element that is substantially equidistant between to the seats of each of the pairs of seats.