摘要:
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.
摘要:
A rotary valve assembly is disclosed in which a rotary valve member is located within a casing having one or more fluid inlets and a plurality of fluid outlets. The rotary valve member has a fluid conduit which extends in a generally radial direction and which communicates with the fluid inlet. Fluid orifices communicate with the fluid conduit and exit through opposite sides of the rotary valve member to thereby minimize, or eliminate altogether, axial forces acting on the rotary valve member. Fluid outlet passages communicate with the two fluid orifices during at least part of the rotation of the rotary valve member to direct the pressurized fluid to the valve outlets. The rotary valve may include a pair of rotary valve members drivingly connected to each other such that they rotate synchronously. The connection may include gear teeth formed on the adjacent peripheries of the rotary valve members such that rotation of one of the valve members causes rotation of the other. Each valve member may have a separate fluid inlet and separate fluid outlets.
摘要:
This injector with two valves (7, 10) which open at different fuel pressures so as to establish a primary flow regime and then a secondary flow regime is characterized in that the primary regime is enriched with fuel via an orifice (21) which adds a branch to the primary flow path of the fuel, but which is closed when the secondary valve is displaced so as to prevent enrichment of the fuel in the secondary regime. This invention applies in particular to certain aircraft engines.
摘要:
A fuel injector for a turbomachine engine, the injector comprising an injector body having pressurized fuel admission means, a first valve mounted downstream from the pressurized fuel admission means and arranged to admit fuel into the injector body, a second valve mounted downstream from the first valve and capable of opening in order to meter at least a fraction of the fuel admitted into the injector body for utilization means for using the fuel, the metered fuel flow rate to the utilization means being a function of flow sections formed through the second valve, the injector further comprising a diaphragm placed between the pressurized fuel admission means and the first valve so as to set the rate at which fuel is admitted into the injector body at a determined value.
摘要:
A rotary valve assembly is disclosed in which a rotary valve member is located within a casing having one or more fluid inlets and a plurality of fluid outlets. The rotary valve member has a fluid conduit which extends in a generally radial direction and which communicates with the fluid inlet. Fluid orifices communicate with the fluid conduit and exit through opposite sides of the rotary valve member to thereby minimize, or eliminate altogether, axial forces acting on the rotary valve member. Fluid outlet passages communicate with the two fluid orifices during at least pan of the rotation of the rotary valve member to direct the pressurized fluid to the valve outlets. The rotary valve may include a pair of rotary valve members drivingly connected to each other such that they rotate synchronously. The connection may include gear teeth formed on the adjacent peripheries of the rotary valve members such that rotation of one of the valve members causes rotation of the other. Each valve member may have a separate fluid inlet and separate fluid outlets.
摘要:
This injector with two valves (7, 10) which open at different fuel pressures so as to establish a primary flow regime and then a secondary flow regime is characterized in that the primary regime is enriched with fuel via an orifice (21) which adds a branch to the primary flow path of the fuel, but which is closed when the secondary valve is displaced so as to prevent enrichment of the fuel in the secondary regime. This invention applies in particular to certain aircraft engines.
摘要:
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.
摘要:
A ball-type sealing device is disclosed for preventing fluid flow out of an orifice wherein the sealing ball is mounted in a body member so as to have both radial or transverse and axial degrees of freedom. The sealing ball, which has a diameter greater than that of the orifice, is mounted in a chamber defined by the body member such that a portion of the ball extends through an aperture in the end of the chamber to the exterior of the body member. The sealing ball is positioned by a pushrod slidably extending into an elongated hole defined by the body member such that one end of the pushrod, having a first contact surface S.sub.1, is in contact with the sealing ball. The opposite end of the pushrod is associated with a second contact surface S.sub.2 which has an area smaller than the contact surface S.sub.1. The sealing ball may be accurately placed in the orifice to be sealed since it has both a transverse degree of freedom, due to the diameter of the chamber in the body member being larger than the diameter of the sealing ball, as well as an axial degree of freedom. Pressure exerted on the sealing ball along the longitudinal axis of the body member exerts a force on the pushrod which, in turn, causes permanent axial deformation of a crush portion of the body member adjacent to the second end of the pushrod. This deformation provides the necessary axial play or clearance between the pushor and the ball.
摘要:
The invention provides an injection system for injecting an air/fuel mixture into a combustion chamber of a gas turbine engine, the injection system having a longitudinal axis and comprising fuel injection means, interposed between first and second air injection means, the fuel injection means being disposed in an annular internal cavity of a Venturi, the fuel injection means comprising at least a first fuel admission circuit provided with at least one fuel injection orifice, and a plurality of second fuel admission circuits independent from the first fuel admission circuit(s), each being provided with at least one fuel injection orifice so as to define a plurality of independent modes of injecting the air/fuel mixture depending on determined operating speeds of the engine, the fuel injection orifice of the first fuel admission circuit being formed in the upstream wall of the Venturi so as to inject fuel towards the combustion chamber in a general direction that is substantially perpendicular to a flow of air coming from the first air injection means, and the fuel injection orifices of the second fuel admission circuits being formed in the downstream wall of the Venturi so as to inject fuel towards the combustion chamber in a general direction that is substantially perpendicular to a flow of air coming from the second air injection means.
摘要:
An assembly method in which a brazing metal is initially filled into radial wells pierced in an annular injection piece having first injection orifices for discharging a primary fuel, and in a cylindrical endpiece surrounding the annular injection piece and having secondary injection orifices for discharging a secondary fuel; thereafter the annular injection piece is fitted inside the cylindrical endpiece and these pieces are together fitted on a first tube for feeding primary fuel and a second tube for feeding secondary fuel and surrounding the first tube, and also to an outer wall of the injector; finally, the end portion of the injector as assembled in this way is placed in an enclosure where it is heated so as to melt the brazing metal to unite the parts.