Abstract: A fuel injector has a metering valve arranged to open under a predetermined feed pressure which constitutes a first threshold pressure, and to remain open in response to said feed pressure increasing so as to deliver fuel to fuel utilization means. The flow rate of fuel passing through the injector is metered to feed said utilization means so long as the feed pressure remains below a second threshold pressure greater than the first threshold pressure. Above the second threshold pressure, the metering valve behaves like a fixed diaphragm as a function of the fluid flow sections formed therethrough. Individual adjustment means are provided so as to enable said second threshold pressure to be adjusted for each injector to ensure that fuel is injected at a uniform flow rate by all of the injectors in a combustion chamber.
Type:
Application
Filed:
November 20, 2001
Publication date:
May 23, 2002
Applicant:
SNECMA MOTEURS
Inventors:
Alain Lavie, Stephanie Martelli, Marion Michau, Jose Rodrigues, Alain Tiepel
Abstract: To control the separation of a hot gas ejection jet within a rocket engine nozzle, the device comprises a jettisonable annular structure for placing around the outside wall of the nozzle at the gas outlet section thereof, which structure defines a radial extension around the nozzle so that in the presence of an outlet jet coming from the nozzle, it creates a low pressure zone in the vicinity of the bottom face of the device, thereby reducing jet separation inside the nozzle.
Abstract: In a turbomachine compressor stator comprising a plurality of variable-pitch vanes (36), each vane mounted in rotation, about an axis of pivoting (38), in a wall (34) forming a surface of revolution about a longitudinal central axis of rotation of the turbomachine (32), being inclined by a specified angle (&agr;) with respect to a plane perpendicular to this longitudinal central axis, there is provision for this wall to be machined locally opposite an end part of each vane (42) so as to form a spherical portion or pocket (40) whose center is positioned on the axis of pivoting and whose radius is determined so as to ensure, over the entire range of operation of the vane, a predetermined minimum clearance between this end part of each vane and the opposite machined spherical pocket while limiting the depth of machining of this pocket.
Type:
Application
Filed:
September 17, 2001
Publication date:
May 23, 2002
Applicant:
SNECMA MOTEURS
Inventors:
Jean-Pierre Caubet, Daniel Dao, Antoine Jean, Didier Merville
Abstract: A hydraulic fuel control unit (100) for an aircraft engine comprises means (14, 2, 16) for controlling cutoff on stop and cutoff on overspeed of a fuel flow transferred by an output (1) to the engine injectors. A logic module (140) controls the position of a state switch (121, 143) into a test position or a normal position. The state module is managed such that the operation of the overspeed module can be tested each time the system is started on the ground. The architecture of the hydraulic unit (100) is such that operation of the cutoff on stop can be tested during each landing. Correct operation in the overspeed test and in the cutoff on stop test is observed by detecting a difference between a control value (153) of an allowable fuel flow that depends mainly on the engine speed, and a real flow value detected by sensors (22).
Type:
Grant
Filed:
March 17, 2000
Date of Patent:
May 21, 2002
Assignee:
SNECMA Moteurs
Inventors:
Jean-Marie Brocard, Alain Pierre Garassino, Christian Denis Le Boeuf, Alain Patrick Paya, Alain Michel Varizat
Abstract: A stator suitable for high-pressure compressors in gas turbine engines includes two points of ventilation at different temperatures. It is recommended that the upstream section of the stator be constructed with a casing and a shroud, both of which are unbroken around a circumference and made of a material with a low degree of thermal expansion. Downstream the shroud is, however, constructed using angular sectors in a material with a higher degree of thermal expansion.
Type:
Grant
Filed:
June 5, 2000
Date of Patent:
May 21, 2002
Assignee:
Snecma Moteurs
Inventors:
Pascal Gérard Gervais, Pascal Michel Daniel Lejeune, Carmen Miraucourt, Jacky Serge Naudet, Patrice Suet, Monique Andrée Thore
Abstract: A process for the early detection of a possible fault in a rotary component of an engine wherein a signal representing an acceleration is stored in a sequential manner; the stored signal is transformed into a frequency signal a spectral coherence calculation is performed between said frequency signal and the same frequency signal shifted by frequency values predetermined as a function of the speed of the engine; the sequences are counted for which a correlation peak appears for one of the predetermined frequencies and a fault is deemed to be present if for a number P of consecutive sequences the number of sequences with a correlation peak is greater than a predetermined threshold.
Type:
Grant
Filed:
March 22, 2000
Date of Patent:
May 21, 2002
Assignee:
Snecma Moteurs
Inventors:
Guy Franck Paul Dusserre-Telmon, David Flores, Frédéric Prieux
Abstract: The present invention concern a method using powder metallurgy for producing molded parts intended to be assembled by self-brazing to metal parts capable of receiving them and said receiving parts. The method comprises forming a homogenous mixture of a basic metal powder, brazing powder and a liquid binding agent which is injection molded to form a self-brazing part.
Type:
Grant
Filed:
July 7, 2000
Date of Patent:
May 21, 2002
Assignees:
Metal Process Systems, Snecma Services
Inventors:
François David, Yves Leroy, Jean-Pierre Huchin, André Malie
Abstract: A method for peening the tops of cooled blades which include cooling air passage orifices. Peening is performed by means of the mobilization of a plurality of beads in a sealed chamber containing at least one blade tip. Said plurality of beads is mobilized by the active surface of a sonotrode which delimits part of said chamber. Said beads have a diameter greater than that of said cooling air passage orifices.
Type:
Application
Filed:
November 16, 2001
Publication date:
May 16, 2002
Applicant:
SNECMA MOTEURS
Inventors:
Benoit J. H. Berthelet, Francis L. G. Chareyre, Willy L. Fradin, Hakim Hoffmann, Stephane Michel Kerneis, Marie-Christine M. Ntsama-Etoundi, Guillaume F. R. Simon
Abstract: The invention relates to an apparatus and to a method for the surface treatment and compressive prestressing by peening of a wall of at least one oblong cavity formed in a part, said cavity opening to the outside via a lateral mouth and having two ends presenting frontal openings. The wall of the cavity is ultrasonically peened by mobilizing a plurality of beads in a chamber delimited by said wall of said cavity, a vibratory surface closing off said mouth of said cavity, and closing-off means closing off said openings, by means of a sonotrode excited by means for producing ultrasonic oscillations. The method and the apparatus are particularly intended for treating a turbine disk comprising a number of axial recesses formed in the periphery of said disk and having wall portions which diverge from each mouth.
Type:
Application
Filed:
November 16, 2001
Publication date:
May 16, 2002
Applicant:
SNECMA MOTEURS
Inventors:
Benoit Jean, Henri Berthelet, Francis Lucien, Guy Chareyre, Willy Lionel Fradin, Hakim Hoffman, Stephane Michel Kerneis, Marie-Christine Marcelle Ntsama-Etoundi, Guillaume Francois, Roger Simon
Abstract: The ventilation assembly designed to cool a stator ring (1) of a turbine machine, finishes on gas blower manifolds (3) composed of symmetric half-shells (7 and 8) attached by welding at their opposite edges and joined together by distributors (4) composed mainly of cylindrical coils acting as spacers placed between the manifolds (3) and welded to them. Finally, the flexible support means comprise rules (6) to complete the assembly of the manifolds to the ring (1).
Abstract: An aircraft engine fuel supply circuit includes a high pressure pump for supplying the engine fuel injectors and supplying a plurality of servovalves for operating various auxiliary mechanisms. In an in-flight re-ignition configuration, with the rotational speed of the engine drops below a threshold value, a fuel economizer valve receives a command to close, thereby shutting off the supply of high pressure fuel to the servovalves. Consequently, the dimensions of the high pressure pump and other associated components in the circuit, especially heat exchangers, may be reduced.
Type:
Application
Filed:
October 25, 2001
Publication date:
May 2, 2002
Applicant:
SNECMA MOTEURS
Inventors:
Marie-Trinite Rose Blot-Carretero, Philippe Galozio, Jean-Marie Brocard, Claude Marcel Maillard
Abstract: The invention concerns a method for producing parts made of thin, light and rigid metal alloy essentially having the following steps: producing a core having the part shape; producing cavities in the core; producing shells made of metal alloy combined with reinforcing fibers with high modulus of elasticity; densifying the shells; and diffusion welding of the shells on the core by compression at temperature and pressure conditions for isothermal forging of the metal alloy used.
Type:
Grant
Filed:
June 15, 2000
Date of Patent:
April 30, 2002
Assignee:
Societe National d'Etude et de Construction de Moteurs
d'Aviation “snecma”
Inventors:
Daniel Georges Girault, Gérard Philippe Gauthier, Ludovic Edmond Camille Molliex
Abstract: A process for attenuating noise generated in a turbomachine by the interaction of rotor blades with stator vanes downstream of the rotor blades comprises the injection of a fluid in continuous jets upstream of the blades through a number of orifices equal to the number of vanes. The orifices are arranged in a ring and are capable of pivoting about the rotor axis by an angle at least equal to the angular pitch between two consecutive vanes. The angular position is controlled so that the sound waves produced by the interaction between the jets and the blades are of opposite phase to those produced by the interaction of the blades with the vanes.
Type:
Application
Filed:
September 21, 2001
Publication date:
April 25, 2002
Applicant:
SNECMA MOTEURS
Inventors:
Angelique Helene Antoine, Eric Jean-Louis Bouty, Alain Alphonse Leopold Thomas
Abstract: A strut (1) fixed to a main portion of turbojet stator carries a ring (5) by a pair of hooks (4, 6) on one side and joining lips (7 and 8) on the other side. In accordance with the invention, the seal is made on the flat sides (10, 11) adjacent to the lips by elastic deflection of the tabs (13) pushing back one of the lips (7). The tabs (13) can also determine the tangential positioning of the ring (5).
Type:
Application
Filed:
October 15, 2001
Publication date:
April 25, 2002
Applicant:
SNECMA MOTEURS
Inventors:
Fabrice Michel Olivier Cot, Alain Dominique Gendraud, Philippe Jean-Pierre Pabion
Abstract: A fuel valve for a fuel flow injection circuit, operating on electrical energy rather than hydraulic energy. The fuel valve has a valve body, a first fuel inlet opening, and a distribution assembly having a plug rotating in a bushing, the plug and bushing each having an opening slit. The valve body includes a fuel outlet opening section made by an overlapping area between the opening in the bushing and the opening in the plug. A plug position unit is provided to control a position of the plug in rotation, and the plug position unit is disposed in the valve body. The valve body further contains an electric motor that drives a rotation of a reduction gear assembly, the reduction gear assembly comprising an input shaft and an output pinion. The plug comprises a toothed sector engaging on the splines of the reduction gear assembly output pinion such that rotating the electric motor causes a rotation of the plug.
Type:
Grant
Filed:
July 21, 2000
Date of Patent:
April 9, 2002
Assignee:
Societe Nationale d'Etude et de Construction de Moteurs
d'Aviation “SNECMA”
Inventors:
Jean-Marie Brocard, Guy D'Agostino, Bertrand Esquevin, Christian Leboeuf, Philippe Prades
Abstract: A protective coating forming a thermal barrier is made on a superalloy metal substrate by forming a bonding underlayer on the substrate, the bonding underlayer being constituted by an intermetallic compound comprising at least aluminum and a metal from the platinum group, and by forming a ceramic outer layer which is anchored on a film of alumina present on the surface of the bonding underlayer. The bonding underlayer preferably has a thickness of less than 50 &mgr;m and is made by using physical vapor deposition, e.g. by cathode sputtering, to deposit a plurality of individual layers alternately of aluminum and of a metal from the platinum group, and by causing the metals in the resulting layers to react together exothermally.
Abstract: An axisymmetric, converging-diverging exhaust nozzle swiveled by a guided vectoring ring (20). The guides comprise three axial apertures (44) which are each located in a base firmly joined to relatively fixed structure and of which the center planes intersect along the longitudinal axis of the turbojet-engine. The side walls (45) of the apertures (43) guide three mutually equidistant spherical rollers (41) fastened to radial stubs (40) firmly affixed to the vectoring ring (20).
Type:
Grant
Filed:
April 14, 2000
Date of Patent:
March 26, 2002
Assignee:
Snecma Moteurs
Inventors:
Didier Georges Feder, Guy Jean-Louis Lapergue, Bertrand Pierre Renaud Monville, Laurent Claude Patrick Salperwyck
Abstract: To support and point a load on a support element, the pointing device comprises distinct link arms distributed around the load. Each link arm comprises a flexible element having a first end connected to the support element via a first hinge having a single degree of freedom, and a second end connected to the load via a second hinge having a single degree of freedom. The pointing device also comprises at least one movement transmission means disposed between the support element and the load to point the load relative to the support element.
Abstract: A flexible rod (20) is articulated at a first end to a control ring (30) and is fixed at a second end to a pivot of a blade (10) that is to be controlled. At this second end, it is held so that it can rotate without play on the blade pivot by holding means (44; 52; 54). The articulation means comprise a pivot (24) passing through a first orifice (22) pierced in this first end and engaged in a radial housing (28) of the control ring, the pivot being held in position by a locking ring (34) which has openings (36) for the passage of this pivot and which slides on this control ring. The fixing means comprise a fixing screw (40) passing through a second orifice (38) pierced in the second end of the rod and introduced into a hole (42) of the pivot of the blade that is to be controlled.
Abstract: In a fluid metering device for metering a fluid from a supply source to means of use of this fluid comprising a metering valve able to slide in a sleeve over a travel C, this valve comprising an intake orifice (16) for admitting the fluid from the said supply source and an orifice (18) for ejecting this fluid to the means of use, there are provided means (20) for channelling the fluid intended to allow, during the movement of the metering valve in its sleeve, a sweeping of the fluid over all the contacting surfaces of the valve and of the sleeve. The means of channelling the fluid advantageously comprise a helical groove of width L and of pitch P.
Type:
Application
Filed:
September 17, 2001
Publication date:
March 21, 2002
Applicant:
SNECMA MOTEURS
Inventors:
Marion Michau, Jose Rodrigues, Alain Tiepel