FIELD: engines and pumps.
SUBSTANCE: group of inventions relates to gas turbine engines and gas turbine plants, including to aircraft turbojets and bypass turbojet, namely to devices for controlling radial clearance between ends of working blades of compressor rotor or turbine and stator of gas turbine engine. Disclosed is an automatic device for thermomechanical control of a radial gap between ends of working blades of rotor and stator of gas turbine engine, comprising segments composed in a ring, enclosing rotor blades of compressor or turbine stage with a given radial gap at ends of blades, and with given gaps between ends of adjacent segments, radially located rods connected to these segments, positioning mechanisms connected to the rods and displacing the rods and segments in radial directions, towards the longitudinal axis of the engine or from it, characterized by that the rods are hermetically and rigidly fixed in the segments in the boss of each segment with interference by pipe thread and resilient split safety lock washer, and rods are made hollow and on their free end of smaller diameter pipe thread is also cut, each segment covers only working blades of the stage impeller, or is made in the form of segment GA of compressor or NA of turbine, segment of external ring of which is made with such width, that its part, free from blades GA or NA with specified initial radial clearance encloses working blades of mating sector rotor, and its segment of internal ring of GA or NA covers with preset initial radial gap in mating sector of rotor teeth of labyrinth seal, and segment of outer ring of segment has radial section in form of U-profile, and segments themselves are located in annular cavity of step body section, formed by two vertical annular flanges, which are either fixed in same flange joints as body section, or by means of radially located pins are fixed on body section, wherein segments are arranged with minimum possible gap on lateral sides of segment, they are made in ring with possibility of displacement in radial directions relative to annular flanges and free thermal expansion, with gaps along their ends located along radial directions, wherein value of each of these gaps is selected as low as possible, providing their allowable value in all operating modes of the engine, with all permissible shifts of segments in radial directions – providing an allowable value of unbalanced force acting on the rod on the side of the gas path of the stage at any moment in time of operation of the engine, and on outer surface of body section there are flat support platforms, on which supports, using pins, screws and lock washers and sealing ring, are tightly fixed, and the rods pass into the second bypass turbojet circuit or into the outside of the outer turbojet body through the holes in the platforms and the central holes in the supports with the least possible clearance, but such that excludes their jamming in all engine operating modes, and the possibility of the segment skewing relative to the axis parallel to the longitudinal engine axis located in a radial plane passing through the point of attachment of the rod to the segment, leading to an emergency situation – collision of the working blades with the end of the segment, the first in direction rotation of the rotor, or recessing the working blades in a segment, or an unacceptable reduction stage efficiency wherein in the bypass turbojet engine the support height and the rod length are such that they do not reach the inner surface of the engine secondary body, and in turbojet engine and bypass turbojet engine, the support height is such that both inner cylindrical surfaces of the support, on which the rod rests on the rod, are spaced along the axis of the rod at a distance between the initial cross-section of one support surface and the end other, approximately equal to the length of the greater arm of the segment, measured from the point attachment of rod to its end, and connection of rod and support is sealed by two pairs of piston rings located in annular grooves of rod, wherein in each pair of piston rings sections of these rings are located diametrically opposite, wherein in case of attachment of annular flange to body section by means of radially located pins, which are fixed against falling out either by lugs made on supports, or by rolling, and on outer surface of body section, or adjacent body section, in plane perpendicular to motor longitudinal axis, there are bosses arranged in the same radial planes as the rods, and in them along threads by means of elastic split lock washers parallel to rods are fixed rods, on free ends of rods and rods by thread with the help of resilient split washers are fixed supports, wherein for each support screwed on the tie-rod, a spacer washer is installed, the thickness of which is selected so that the flat support surfaces of the supports screwed on the rod and tie-rod located in one radial plane, were perpendicular to the longitudinal axes of the rod and tie-rod and located on one radial size, measured from engine longitudinal axis, and each positioning mechanism consists of a lever of the second kind and rod and tie rod hinged to it by their supports, and each lever of the second kind consists, in fact, of a lever made in the form of a flat plate, supports with lugs, and hinged connection of supports of rods and rods with levers, providing displacement of rods and thermal elongation of rods strictly in radial directions to longitudinal axis of the engine and from it, is made by means of axles, with tension of the supports fixed in the lugs holes, and freely passing through the through slots in the lever, wherein the width of each slot is equal to the diameter of the axis, and its length is such that when the levers are rotated, the axles are freely slid about the sides of the slot, through which the lever contacts the axes, and all axes in the holes in which they are fixed are additionally locked from their displacement and rotation with lock screws, wrapped in lugs, and locking screws themselves are locked from turning by rolling or coring, and lever itself is fixed in its support with possibility of free rotation relative to axis similarly fixed in its support, and with zero gap passing through hole in lever, wherein lever is located between eyes with clearance along its sides 0.05÷0.15 mm, and using pins, screws and lock washers, the lever support is fixed on the device housing support platform, and supports of rod and tie rod, hingedly connected to lever, are fixed on bearing sites of supports, screwed on rod and tie-rod, and housing of proposed device is made of composite material with coefficient of temperature expansion, several times less coefficient of temperature expansion of material of body section, on which traction rods are fixed, and is made in form of ring, in bypass turbojet enclosing ring shell of first engine and part of proposed device, and in turbojet enveloping outer body of engine and parts of said device, wherein on inner surface of said ring there are distributed in circumferential direction flat support areas, on bearing planes of which, perpendicular to central radial planes of sites, are fixed by pins, screws and retainers of support levers, and on one of the ends of the body rectangular flanges are made, by which the body using bolts and self-locking nuts is fixed to rectangular flanges of heat compensators located in the same radial planes as rods and rods, and the heat compensator itself is made of a ground polished tape made from heat-resistant stainless steel, which is bent into an accordion, and the compensators are fixed to rectangular flanges by rivets, the rectangular flange is also made of composite material, and the compensator is centered and secured to the body section in the same flange joint, as the body section itself is attached to the outer body of the first bypass turbojet circuit or to the outer housing of the turbojet engine, and in three supports screwed on tie rods equally spaced along circumference, by thread with the help of resilient split lock washers in the same radial planes as tie rods, parallel to them rods are fixed, passing through holes in steel bushings pressed in body, with as small as possible gap, but such that eliminates possibility of jamming of rod in body at thermal extension of thrust, each group of parts of the device located inside the body is closed by a fairing made of composite material, made in the form of a hollow blade with a symmetrical profile of the cross section, and fixed on the body or on the body and support sites of the body section by screws and lock washers, and in the body above the attachment points of supports positioning mechanisms to supports screwed on rods, process holes are made, and to use the device on two adjacent stages, it is simply replicated except for body, compensator, rods and fairings, but with other required design parameters, which can be changed quantitatively, and wherein body, compensator, rods and fairings are made common for devices of both stages.
EFFECT: enabling the design simplification.
15 cl, 25 dwg
