RU2602470C2 - Turbo-fan engine fan rotor front support - Google Patents

Abstract

FIELD: engines.

SUBSTANCE: invention relates to aircraft turbo-fan engines (TFE). Disclosed is turbo-fan engine fan rotor front support containing hub, bearing housing, two resilient elements, connected in parallel so that their stiffnesses are summed, roller bearing, lubricated by bubbling, trunnion, shaped bushing fixed on trunnion and inner bearing race fixed by flange and segmented contact seal rotating parts, segmented contact seal, consisting of threaded bushing fixed on trunnion, ring connected with said bushing by thread, three graphite o-rings composed of separate segments, pressed to ring contacting with them by two springs so that between these rings faces remains gap of 0.05÷0.1 mm, two of them are inserted one into another without clearance, and third ring is butt-to-butt installed to these two rings, wherein joints of these rings segments are spaced apart in circumferential direction, support pre-oil cavity labyrinth seal consisting of labyrinth ring and stator element, pipe located inside trunnion and forming air cavity in it, and openings are made in shaped bushing and trunnion, through which oil is supplied for cooling of ring in contact with graphite seal rings, and in pipe, trunnion and labyrinth ring openings are made, through which air is supplied for support pre-oil cavity supercharging, characterized by that bearing housing is made integral with both resilient elements made in form of resilient rings with evenly alternating external and internal ledges, tightness between bearing outer race and resilient rings inner projections is equal to 0÷h/2 mm, where h is resilient rings ledges height equal to h = 0.15÷0.3 mm, in bores made in bearing outer race from its both sides, press-fitted two bushings with polished ends made of steel or bronze BrS30, and ends of gap between hub and bearing outer race, in which resilient rings are arranged, are sealed by metal o-rings, which are pressed by mating polished ends to polished ends of these bushings by rubber o-rings, arranged in annular grooves in bearing housing collar and segmented contact seal housing, and on each metal o-ring projection is made, which accordingly enters into mating slot made in bearing housing collar or segmented contact seal housing with gap along slot perimeter, smaller than metal sealing ring displacement, at which mutual slippages of metal and rubber o-rings occur, and equal to 0÷0.05 mm, and at outer bearing race ends projections are made entering mating slots in metal sealing rings with gap along slot perimeter, equal to or slightly larger than permitted trunnion offset in hub, with gap of 0.15÷0.3 mm, and radial gap between metal o-rings and bearing casing is less than metal sealing ring displacement, at which of metal and rubber o-rings mutual slippages occur, less than 0.1 mm, and radial distance from outer surface that limits rubber o-ring with metal sealing ring contact zone, to of metal sealing ring external cylindrical surface is such, that hydraulic pressure acting on each metal sealing ring on side of rubber sealing ring, balances in case of joint opening between metal sealing ring and bearing external ring hydraulic pressure acting on metal sealing ring on side of bearing external ring, and bushing thread inner diameter fixed on trunnion is equal to or larger than inner bearing ring outer diameter, and threaded joint is sealed by rubber o-ring arranged in bushing and ring circular bores, and between ring and labyrinth ring split resilient ring is installed, in free state centered by labyrinth ring belt, cylindrical surfaces of two graphite rings, inserted into each other, by which they are in contact, are made with eccentricity relative to said pair internal ring cylindrical surface, by which it is in contact with ring screwed onto bushing, and as springs pressing graphite sealing rings segments to ring contacting with them, two circular multilayer corrugated packages are applied assembled "corrugation in corrugation" from ground hard drawn steel tapes or tapes, made from hardened stainless steel, wherein tapes ends joints are uniformly distributed along corrugations tops, each corrugated tapes package with radial tension along corrugations tops, created identical by simultaneous compression of all package corrugations in radial directions, is inserted into annular gap between segmented contact seal housing and graphite sealing ring, on which it thrusts against stop into each other and in this housing wall so that its tops are arranged in mating semicircular segmented grooves, made in parts contacting with packages, and segmented contact seal on side of support pre-oil cavity is closed by cover and sealed by rubber o-rings, arranged in cover annular grooves, and segmented sealing cover and housing are made from steel of same grade or bronze BrS30, wherein annular gap between segmented sealing housing and cover is also less than 0.1 mm, and blind slot is made in cover, in which enters stop with total gap on slot lateral sides of less than 0.1 mm, tightly part with conical pipe thread secured in segmented sealing housing and secured by resilient ring, and cover by elastic forces created by resilient split ring arranged in segmented sealing housing annular groove, and air pressure supplied into pre-oil chamber through openings in pipe, trunnion and labyrinth ring, is pressed with polished end to graphite o-rings mating polished ends, and in bearing housing collar throttling orifice is made communicated with gap along slot perimeter made in metal sealing ring.

EFFECT: rotor support.

1 cl, 8 dwg

Description

The invention relates to aircraft dual-circuit turbojet engines (turbofan engines).

The design of the front support of the rotor support of the high-pressure compressor of the AI-25 turbofan engine (see A.S. Vinogradov. Design of the AI-25 turbofan engine. Electronic textbook. Samara State Aerospace University. Samara, 2013. - p. 46, 47), comprising a bearing housing, a ball bearing, an elastic ring with protrusions on the outer and inner diameters arranged so that the protrusion on the outer diameter falls in the middle between the protrusions on the inner diameter. A cup is pressed into the bearing housing with special windows for draining the oil and a collar to absorb axial loads acting on the ball bearing. A pin is pressed into the end of the collar, which fixes a smooth ring from rotation, fitted with an interference fit on the outer race of the bearing. An elastic ring with protrusions is installed between the glass and the smooth ring and secured against twisting relative to the latter by two end protrusions included in the mating grooves made on the shoulder of the smooth ring. The radial-mechanical contact seal of the support consists of a sleeve mounted on the rotor shaft, a split graphite sealing ring, which is pressurized by the end face against the flat surface of this sleeve, and the outer surface is against the cylindrical surface of the sleeve installed in the glass, thus preventing oil from entering from the bearing cavity to the air path. An adjusting ring is installed between the sleeve installed in the cup and other non-rotating parts of the support, which serves to ensure a guaranteed minimum clearance between the end face of the outer race of the bearing and this sleeve.

The disadvantages of this elastic support of the rotor of the turbomachine are: its slight damping ability, due to the fact that the oil during deformation of the ring is freely extruded from the gaps formed by the protrusions of the elastic ring into their loose ends;

large radial dimensions of the support, due to the presence, in addition to the most elastic ring, of another glass and a smooth ring fixed respectively in the housing and on the bearing.

Also known is the design of the front elastic damper support of the rotor of a fan of a turbojet dual-circuit engine with an afterburner AL-31F (see Turbojet dual-circuit engine with an afterburner AL-31F. Study guide. Edited by A.P. Nazarov. Edition of VVIA named after Akad. N .E. Zhukovsky, publ. 12/29/1994, p. 55). The supporting element of the support is a roller bearing lubricated by bubbling. The inner ring of the bearing, the rotating elements of the segment contact seal, which seals the oil cavity of the support, are mounted on the front axle. From axial movements, they are fixed by a flange of a figured sleeve mounted on a pin. The outer ring of the bearing and the non-rotating elements of the segment contact seal are mounted in one steel housing that is attached to the bearing housing. The bearing housing is elastically movable and connected to the fixed hub flange through fifty elastic jumpers of the “squirrel wheel” type. A multi-support elastic ring with calibrated holes made in the spans of the ring between the protrusions is installed in the gap between the bearing housing and the hub. When the rotor vibrates, the multi-support elastic ring is deformed, the oil flows through calibrated holes from one cavity to another, dissipating the energy of rotor vibrations. To cool the ring mounted on the pin, to which the graphite O-rings of the segment contact seal are in contact, through the holes in the figured sleeve, pin and the sleeve fixed on the pin and fixing the bearing inner ring from axial displacement, oil is supplied from the oil cavity inside the pin, which Clearances in the thread along which the ring is connected to this sleeve are discharged into the oil cavity of the support. The segment seal contains three graphite rings, two of which are inserted into each other without a gap, and the third ring is installed end-to-end with them. The segments that make up the graphite o-rings are pressed against the ring in contact with two bracelet springs so that there are 0.05–0.1 mm gaps between the ends of the segments. Moreover, the joints of the segments of these rings in the circumferential direction are spaced from each other. The third graphite sealing ring with compression springs equally spaced around the circle presses the other two sealing graphite rings with their ends against the mating end of the segment seal housing. At the other end, the springs abut against the washer and the paranitic gasket fixed in the glass. The oil cavity of the support is pressurized by drained air from the pre-oil cavity of the support, into which it enters through the labyrinth seal. The pre-oil cavity of the support, in turn, is pressurized by air from the pressurization cavity, sealed with its labyrinth seal. Air enters the pressurization cavity from a pipe located inside the axle and forming an air cavity in it, through the openings in it and the axle.

This support has two elastic elements - a multi-support elastic ring and a squirrel-wheel-type sleeve, the stiffnesses of which are connected in parallel (summed). This allows you to obtain the required greater rigidity of the support, and at the same time lower stresses are provided in these elements.

But this greatly complicates the construction of the support, leads to the appearance of various "intermediate" parts and significantly increases its overall dimensions, especially the axial ones, due to the use of a squirrel-wheel-type sleeve.

In this construction of the support, several sealing rubber gaskets were used, which not only work on cyclic compression, but on which during the trunnion precession, the steel parts in contact with them slip with dry friction, which reduces the operating time of these seals until they are replaced.

The implementation of a large number of calibrated holes of small diameter in a multi-support elastic ring significantly complicates the technology of its manufacture, increases the likelihood of their coking during support operation at elevated temperatures.

The damper of the bearing is filled with oil through the holes in the bearing housing directly from the oil cavity of the bearing. The hydraulic resistance of this tract is small. Due to this, the pressure drops across the calibrated holes and hydraulic losses in them are reduced. Therefore, the damping properties of the support are reduced.

Note that this drawback - filling the damper with oil directly, through elements with low hydraulic resistance from the oil cavity of the support or connecting the cavity of the damper with the oil cavity of the bearing through these elements, in our opinion, is typical for the supports of modern turbomachines.

Among the disadvantages of this support should also include the possibility of rotation of the multi-support elastic ring during precession of the rotor.

This elastic support of the rotor of the turbomachine by technical essence is the closest to the proposed invention and is taken as a prototype.

The task is to create a front support for the turbofan fan rotor with good elastic and strength characteristics, simpler in design, with smaller radial and axial dimensions, with higher damping characteristics than the prototype, and with a simpler design than that of it, segmented contact seal , with the exception of the design of the rubber sealing rings, along which the parts in contact with them slip with dry friction, with reliable fixation from the rotation of the elastic element and high wear ykostyu its projections, with convenient technology, its assembly and routine maintenance to replace worn parts support, during which do not require a fan rotor rebalancing.

The problem is solved by the fact that it is proposed that the front support of the rotor of the fan of the turbofan engine contains a hub, a bearing housing, two elastic elements connected in parallel so that their stiffnesses are summed, a roller bearing lubricated by bubbling, a pin, a figured sleeve mounted on a pin and fixing the flange of the inner ring of the bearing and the rotating parts of the segment contact seal, the segment contact seal, consisting of a sleeve with a thread mounted on the axle, to the ring, by the thread connected to this sleeve, of three graphite o-rings made up of separate segments pressed against two rings by a spring so that a gap of 0.05–0.1 mm remains between the ends of the segments of the rings, two of which without the gap are inserted into each other, and the third ring is installed end-to-end to these two rings, and the joints of the segments of these rings in the circumferential direction are spaced from each other, the labyrinth seal of the pre-oil cavity of the support, consisting of a labyrinth ring and a stator element, pipes located inside the journal and forming an air cavity in it, and in the figured sleeve and the journal holes are made through which oil is supplied to cool the ring in contact with the graphite sealing rings, characterized in that the bearing housing is made in one piece with both elastic elements made in the form of elastic rings with uniformly alternating external and internal protrusions in such a way that its middle part is made in the form of these rings and the end cylindrical part of the housing with a flange for fastening I have it to the hub and the other end part of the body with an inner collar is rigidly connected to these elastic rings along the length of each outer protrusion, and on the length of each inner protrusion and the adjacent two spans, each elastic ring is separated from these parts of the body through openings, the outer cylindrical the surface of these parts and the outer cylindrical surface of the outer protrusions of the elastic ring is one and the same surface along which the housing is tightly fixed in the hub, and the magnitude of this interference the wound is possibly smaller, but such that with additional fastening of the housing to the hub with bolts and self-locking nuts at all engine operating modes, the reliability of the housing – hub connection is ensured, and the diameter of the inner cylindrical surface of the cylindrical part of the housing with the flange is either equal to or larger than the diameter the surfaces of the depressions between the inner protrusions of the elastic ring, and the diameter of the inner cylindrical surface of the cylindrical part of the housing with the inner shoulder is either equal to or less than the diameter of the outer the surface of the inner protrusions of the elastic ring, the interference between the outer ring of the bearing and the inner protrusions of the elastic rings is 0 ÷ h / 2 mm, where h is the height of the protrusions of the elastic rings, equal to h = 0.15 ÷ 0.3 mm, in bores made in on the outer ring of the bearing on both sides, two bushings with polished ends made of steel or bronze BrС30 are pressed in, and the ends of the gap between the hub and the outer ring of the bearing, in which the elastic rings are located, are sealed with metal sealing rings that are pressed by the mating polishes end faces to the polished ends of these bushings with rubber sealing rings located in the annular grooves in the shoulder of the bearing housing and the housing of the segment contact seal, and on each metal sealing ring one or two rectangular protrusions are located, located on its diametrically opposite halves, which are respectively included in the response grooves made in the shoulder of the bearing housing or the housing of a segmented contact seal with a gap around the groove perimeter less than the displacement of the metal of the O-ring, in which mutual slippage of the metal and rubber O-rings occurs, and equal to 0 ÷ 0.05 mm, and at the ends of the outer ring of the bearing protrusions are made, which enter into the mating grooves in the metal O-rings with a gap around the groove equal to or slightly greater than the permissible offset of the trunnion in the hub and equal to 0.15 ÷ 0.3 mm, and the radial clearance between the metal o-rings and the bearing housing in the case of one rectangular protrusion on each metal the o-ring is less than the displacement of the metal o-ring, in which mutual slippage of the metal and rubber o-rings occurs, less than 0.1 mm, and in the case of two rectangular protrusions - less than 0.2 mm, and the radial distance from the outer circumference limiting the contact zone a rubber o-ring with a metal o-ring, to the outer cylindrical surface of the metal o-ring, such that the hydraulic pressure acting and each metal O-ring on the side of the O-ring, balances in the case of a joint between the metal O-ring and the outer ring of the bearing opening, the hydraulic pressure acting on the metal O-ring on the side of the outer ring of the bearing, and this is the radial distance of the metal O-ring in contact with the shoulder bearing housing, equal to or more than half the radial size of the annular contact area of the sleeve, pressed into the outer ring of the bearing, with a metal sealing ring, and on the other end of the bearing it is larger than that described for h / 2, and on the outer cylindrical surface of the metal sealing rings two, three or more equally spaced circular grooves of 4 ÷ 5 mm wide can be made and 0.2–0.5 mm high, metal o-rings are made of the same material as the bearing housing, and in the manufacture of bushings pressed into the outer ring of the bearing, steel has a hard contact surface The number of metal O-rings is less than the hardness of the contact surfaces of the bushings, and oil is fed into the gap occupied by elastic rings through holes and an annular groove made in the hub above the slots located between the elastic rings from a sealed container made in the tide on its outer surface, the number the holes made in the hub, and their diameter, are selected as small as possible, but such that at all engine operating modes, the cavities between the protrusions of the elastic rings and the core are completely filled the segmented contact seal housing is centered on the bearing housing and fastened to the hub flange with bolts, lock washers and self-locking nuts, for which the bearing housing flanges and the segmented seal housings are made with troughs evenly spaced along the periphery of the flanges, and the troughs of one flange are offset from the troughs of the other flange so, that the bolt heads securing the bearing housing are located in the depressions of the flange of the housing of the segment contact seal, and on the protrusions formed by the depressions of the flange of the housing contact seal, bosses are made, in the holes of which there are bolts fastening this flange, and the height of these bosses is such that this housing is pressed with its flange to the bearing housing flange, and the bosses are pressed against the hub flange, and the joints between all these flanges are sealed with rubber sealing rings, and the inner diameter of the thread of the sleeve fixed on the axle is equal to or greater than the outer diameter of the inner ring of the bearing, and the direction of winding of the threads is such that for a given direction of rotation of the fan h Oil particles from the threaded connection of this sleeve and the ring in contact with graphite sealing rings made up of separate segments were thrown into the oil cavity, and the moment of friction forces acted on this ring to screw it on, and the threaded connection itself was sealed with a rubber sealing ring placed in the ring bores of the sleeve and the ring, and between the ring and the labyrinth ring there is a split elastic ring, in the free state centered along the belt of the labyrinth ring, cylindrical the surfaces of two graphite rings inserted into each other, on which they contact, are made with eccentricity with respect to the cylindrical surface of the inner ring of this pair, along which it is in contact with the ring screwed onto the sleeve, and as springs, pressing the segments of the graphite o-rings to the ring in contact with them, two ring multilayer corrugated bags are used, assembled “corrugations into corrugations” of polished steel cured tapes or tapes made of hardened stainless steel and, moreover, the joints of the ends of the tapes are evenly distributed over the vertices of the corrugations, and there is a gap between the ends of each tape, the size of which is selected as small as possible, but to avoid overlapping the ends of each tape against each other when creating an interference fit on the vertices of the corrugations of the packet and the maximum allowable radial displacement of graphite O-rings, and a wear-resistant coating is applied to the surface of the tapes, each packet of corrugated tapes with a radial interference over the corrugated tops, created by the same simultaneous compression of all The ditch of the packet in radial directions is inserted into the annular gap between the housing of the segmented contact seal and the graphite sealing ring on which it rests against each other and into the wall of this housing so that its vertices are located in reciprocal recesses made in contact with packages of parts in the form of segments with an arc of a circle of radius R, determined from the relation:

where H ₁ is the maximum value of the additional displacement of the corrugation tip in the radial direction obtained by precessing the trunnion in the support with the maximum allowable displacement amplitude due to the displacement in the circumferential direction of the vertex of that corrugation in the recess that is maximally displaced in this direction, S ₁ is the half of the maximum chord displacements of this corrugation in the circumferential direction, and a chord notch, of a larger magnitude:

where H is the greatest depth of the recess, less than 1.5 mm, and the maximum size of the gap in the hollows of the corrugations, measured along the radius from its top to the part in contact with the package, is greater than the height of the protrusions of the elastic rings, and holes or recesses are made in the wall in places corresponding to corrugation hollows, and between the wall and the ring in contact with graphite o-rings made up of separate sectors, there is an annular gap greater than the permissible displacement of the ring in the support, and a segmented contact seal on the pre-oil side the support cavities are closed by a lid and sealed with rubber sealing rings located in the annular grooves of the lid, and the lid and the segment seal housing are made of steel of the same grade or BrC30 bronze, and the annular gap between the segment seal housing and the cover is also less than 0.1 mm, and the cover is made with a non-through groove, in which with a total clearance on the sides of the groove less than 0.1 mm, an emphasis enters, tightly secured with a conical pipe thread, fixed in the segment seal housing and locked elastic m ring, and the lid by elastic forces created by an elastic split ring placed in the annular groove of the segment seal housing and the pressure of the air entering the pre-oil cavity of the support through the holes in the pipe, trunnion and labyrinth ring, is pressed by the polished end to the mating polished ends of the graphite sealing rings and a throttle hole is made in the shoulder of the bearing housing, communicating with a gap around the perimeter of the groove made in the metal sealing ring, or in the outer ring of the bearing le orifice communicating with a slot in the middle cross-section of the bearing housing.

The prototype already uses a damper made in the form of an elastic ring with alternating outer and inner protrusions equally distributed around the circumference and throttle gauge holes.

Naturally, it is advisable to perform the second elastic element of the support in the form of a similar design, which allows, compared with the prototype, while providing the same required stiffness of the support, at least double its damping ability and, significantly, simplify the design of the support and reduce its axial dimension

This is done in the proposed support, and its damping ability is increased significantly more than twice, due to the fact that when the axle is precessed in the support, oil from the high-pressure region in the damper, organized by elastic rings, is forced through with large hydraulic losses through the depressions formed external and internal protrusions, moving along the "long path" in the circumferential direction, falling from the depressions formed by the external protrusions, into the depressions formed by the internal protrusions, and vice versa. In this case, there is no need to perform throttled calibrated holes in the elastic rings.

The proposed front fan rotor support of the turbofan engine has a significantly smaller radial size of the annular space between the hub and the outer ring of the bearing due to the absence of the proposed support cup, mounted on the outer ring of the bearing, and the implementation of both elastic rings in one piece with the bearing housing fixed in the hub. This embodiment of the elastic rings and the housing eliminates the possibility of their rotation during the precession of the journal.

An important feature of the proposed support is also the separation of the paths supplying oil to the damper and the oil cavity of the support, which communicates with the damper path only through throttling elements with high hydraulic resistance - a gap around the perimeter of the protrusion on the outer ring of the bearing and a throttle hole made in the shoulder of the bearing housing through which oil is drained from the damper. Due to this, the hydraulic resistance of the damper path is increased, and, therefore, its damping ability is increased.

For the proposed support, slipping with dry friction in the damper can occur only along the internal protrusions of the elastic rings, but at the proposed interference values along these protrusions, during the trunnion precession, part of the internal protrusions located opposite to the dynamic and static forces acting on the support will detach. In this case, abundant lubrication of the contacting surfaces of these protrusions occurs, due to which the rate of their wear is significantly reduced. In addition, the contacting surfaces of these protrusions may be nitrided and a wear resistant coating may be applied to them.

When making bushings pressed into bores in the outer ring of a bearing made of BrС30 bronze, the coefficient of sliding friction between the metal sealing rings and these bushings decreases by a factor of ten, and, therefore, the wear rate of parts of this pair decreases by a factor of ten.

If the sealing joints are opened between the metal sealing rings and the bushings pressed into the outer ring of the bearing and the oil gets into the joint in the contact zone, hydraulic pressure is generated, distributed along the length of the radial size of the zone along a right triangle with a leg equal to the oil pressure at the end sections of the damper clearance, and in the gaps between the metal sealing rings and the housing of the segmented contact seal and the shoulder of the bearing housing in areas from the outer th circle bounding the contact zone of the rubber sealing ring to the outer cylindrical surface of the metallic sealing rings on the radial size of the zone, the hydraulic pressure will be distributed by the diagram of a rectangular with a side of the rectangle, equal oil pressure in the end sections of the damping gap.

Therefore, with the outer diameter of the rubber rings selected above and concentric with respect to the axis of the trunnion of the rubber rings, the resultant hydraulic pressure forces acting on the metal O-ring when opening the joint sealing the damper gap will balance each other, and the joint will close under the resultant elastic forces created by the rubber o-ring.

The proposed support excludes the possibility of slipping parts with dry friction on the contact surfaces of all rubber sealing rings used in the support, due to which their wear is eliminated or significantly reduced and the operating time between successive replacements of these rings is increased.

Inadmissible wear of metal o-rings is achieved over a period of time that is several times longer than the period during which unacceptable wear of rubber o-rings that seal the damper gap of the prototype is achieved, and in the case of split metal o-rings, most often used in the construction of modern rotor supports turbomachines, due to the fact that the proposed metal rings have a contact area several times larger and a contact pressure several times smaller. At the proposed support, the time interval between routine maintenance on the support is determined by the aging time of the rubber of the o-rings. Replacement of metal o-rings due to their unacceptable wear can be combined in time with one of the replacement o-rings.

The time to achieve unacceptable wear of metal sealing rings at the proposed support can be increased by applying to their surface in contact with the bushings pressed into the outer ring of the bearing a wear-resistant coating, for example, solid lubricant or silver plating.

When performing metal o-rings with one rectangular protrusion, the radial clearance between them and the bearing housing must be less than the displacement of the metal o-ring, in which mutual slippage of the metal and rubber o-rings occurs, i.e. be less than or equal to 0.1 mm. In the case of manufacturing two opposite rectangular protrusions on each metal sealing ring, when choosing the size of this gap, there is no need to take this condition into account, and the range of permissible values of radial clearances is chosen to be large (less than or equal to 0.2 mm) and one that eliminates the need for selective selection of metal o-rings.

Here, a rectangular protrusion is understood to mean a protrusion in which the sides forming a gap with a reciprocal groove are sides of a rectangular parallelepiped. The implementation of the protrusions and reciprocal grooves with such a geometric shape, firstly, simplifies the manufacturing technology of the groove, and secondly, is one of the conditions that ensure the exclusion of selective assembly during their execution.

The implementation of the metal sealing rings and the bearing housing from the same material ensures the constancy of the maximum value of the annular gap between them at all operating temperatures of the support and, therefore, ensures the absence of mutual slipping between the sealing rubber and metal rings in all operating modes of the turbofan engine.

The lower hardness of the material of the metal sealing rings in comparison with the hardness of the material of the bushings in contact with them reduces the wear of these bushings.

We also note that the manufacturing technology of metal sealing rings is not more complicated than the manufacturing technology of split metal sealing rings, and their application in this case allows us to simplify the design of the bearing, since in this case there is no need to produce ring grooves in its outer ring.

The use of metal sealing rings, elastically pressed by the sealing rubber rings to the bushings pressed into the outer ring of the bearing, provides more comfortable working conditions for the bearing and eliminates the possibility of burning in it.

The ring multilayer multi-span corrugated bag used in the proposed support in the segment contact seal instead of bracelet springs is structurally simple. The technology of its manufacture is known (an annular multilayer corrugated bag, although of a different design, is used in rotor bearings of commercially available gas turbine engines NK-12 MB, NK-12 ST, etc. as a damper) and can be significantly simplified by manufacturing the package from standard steel polished quartered tapes and reducing the requirements for the accuracy of the manufacture of the package - the assumption of small gaps between the tapes in the assembled package, which is acceptable, since it has little effect on its elastic damping characteristics. In the case of using a corrugated bag as a spring compressing segments of a contact segment seal, in our opinion, it is permissible to make bags by rolling a pack of cured tapes through a pair of gears, then compressing them between two planes and unloading and folding them into a ring when they are assembled into a seal.

The proposed design of the package due to the uniform placement of the joints of the ends of the tapes at the corrugation tops has isotropic stiffness and damping properties and therefore uniformly presses the segments of the graphite sealing ring to the steel ring in contact with it, which, in turn, ensures uniform distribution of wear in the circumferential direction of the segments of the graphite ring and reduces the intensity of their wear.

In addition, uniform wear of the segments to the point where, due to this wear, the segments end up against each other, only reduces leakage through the segment contact seal.

The placement of the corrugation vertices of each package in semicircular segment grooves, respectively made in the segment contact seal housing and in the segments of the graphite O-ring contacting it during pre-processing of the journal in the support, fixes the packet and this graphite O-ring, and the execution of the cylindrical surfaces of two graphite rings inserted to each other, on which they contact, with an eccentricity, for example, 1 ÷ 1.5 mm relative to the cylindrical surface of the inner ring this pair, through which it is in contact with the ring, screwed onto the sleeve, fixes this ring from turning. In our opinion, such a constructive solution is preferable to fixing in rotation of the graphite sealing rings of the segment contact seal with stops, which is used in modern gas turbine engines.

When performing the maximum gap size in the corrugations of the corrugations, measured along the radius from its top to the part in contact with the package, greater than the height of the protrusions of the elastic rings, the limiter of permissible axle displacements in the support during its precession is the depth of the hollows of the elastic rings (the height of their protrusions).

The presence of an elastic split ring, pressing the cover of the segment contact seal to the graphite sealing rings, ensures the reliability of its operation when the engine is idle, when it starts and in transitional modes of the engine.

The diameter of the Central hole in the wall of the housing of the segmented contact seal and in its cover more than two permissible displacements of the journal in the support of the outer diameter of the ring in contact with the graphite sealing rings, allows axial displacement of the rotating parts of the bearing relative to the stator parts of the bearing, due to the temperature elongations of the engine parts in work, and allows you to dismantle from the support a node assembled from all the stator elements of the support, and a worn ring in contact with graphite with O-rings, without dismantling parts rotating together with the pin, mounted on it with a high interference. This makes it possible to replace the worn parts of the support during routine maintenance on the engine, since this operation of the proposed support is quite simple and eliminates the need for rebalancing of the fan rotor. Accordingly, the assembly of this assembly and the ring into the support is quite simple as well.

The installation order in front of the oil cavity of the support is first one graphite ring, and then two different from the prototype and is selected because one graphite ring allows oil leakage in radial directions from the cracks between the ends of the segments. This oil enters the cavity occupied by the corrugated bags and lubricates their contact surfaces.

The hub of the proposed support is made of titanium, and the bearing housing is made of steel, since the coefficient of thermal expansion of titanium is less than that of steel, in the operating modes of the turbofan engine the interference between these parts will only increase. Therefore, with additional fixing of the housing with bolts and self-locking nuts, the value of this interference can be chosen convenient for dismantling and mounting the housing when replacing it in case of unacceptable wear of the inner protrusions of the elastic rings.

In order to improve the cooling of the ring in contact with graphite o-rings, a front support for the fan rotor of a double-circuit turbojet engine is proposed, characterized in that the tops of the threads made on the sleeve, on which the ring in contact with the graphite o-rings is screwed, are cut flat, or the tops of the threads of the thread cut both on the sleeve and on the ring are cut flat.

Cutting the vertices of the threads of these parts increases the clearance of the spiral channel between the peaks and troughs in the threaded pair, and, consequently, the oil flow through the channel increases and the cooling of these parts improves.

The proposed design of the front support of the rotor of the fan of a dual-circuit turbojet engine is illustrated by figures. In the figures, parts not described in the description of the structures of the proposed supports are made similarly to the design of these parts of the prototype, and in FIG. are depicted by a thin solid line as “decor” in the assembly drawing.

In FIG. 1 shows a longitudinal section of the proposed front support of the turbine fan rotor.

In FIG. 2 shows a section along AA in FIG. one.

In FIG. 3 shows a section along BB in FIG. 1. The image is enlarged.

In FIG. 4 shows the bearing housing of the front fan rotor support.

In FIG. 5 is a view according to page B in FIG. one.

In FIG. 6 is a view taken along page D in FIG. 3.

In FIG. 7 shows a section along DD in FIG. one.

In FIG. 8 shows a section along EE in FIG. 1. The image is enlarged.

The proposed front fan rotor support of a turbofan engine (see Fig. 1) contains a hub 1, a bearing housing 2, mounted on the hub 1 with bolts 3, washers 4 and self-locking nuts 5, two elastic rings 6 with uniformly alternating outer 7 (see Fig. .2) and internal protrusions 8 connected in parallel so that their stiffnesses are summed, a roller bearing 9 (see Fig. 1) lubricated by sparging, pin 10, a figured sleeve 11 mounted on pin 10 and fixing the inner ring 13 of the bearing flange 12 9 and rotating the other parts of a segmented contact seal, a segmented contact seal, consisting of a sleeve 14 with a thread fixed on the pin 10, a ring 15, threaded to a sleeve 14, three graphite o-rings 16, 17 and 18, composed of individual segments 19 (see Fig. 3), pressed against the ring 15 in contact with them (see Fig. 1) by two springs made in the form of annular multilayer multi-span corrugated bags 20, so that a gap 21 remains between the ends of the segments 19 (see FIG. 3), equal to 0.05 ÷ 0.1 mm, the housing of the segment contact seal 22 (see Fig. 1), mounted on the bearing housing 2, and the cover 23. The proposed support also includes a labyrinth seal pre-oil cavity 24 of the support, formed by a labyrinth ring 25 mounted on a pin 10 and a housing of a segmented contact seal 22, a pipe 26 located inside the pin 10 and forming an air cavity 27 therein. In the figured sleeve 11 separating the oil 28 and the air cavity 27 in the pin 10, the holes 29 are made in the sleeve 14 and the pin 10 itself, through which oil is supplied to cool the ring 15 in contact with the graphite sealing rings 16 and 17. In the pipe 26, the pin 10 and the labyrinth ring 25, holes 30 are made through which air is supplied to pressurize the pre-oil cavity 24 of the support. The bearing housing 2 is made in one piece with both elastic rings 6 (see Fig. 4) so that its middle part is made in the form of these rings and the end cylindrical part 31 of the housing 2 with a flange 32 for attaching it to the hub and the other end part 33 of the housing 2 with the inner collar 34 are rigidly connected to the elastic rings 6 along the length of each outer protrusion 7, and on the length of each inner protrusion 8 and the adjacent two spans 35, each elastic ring 6 is separated from these parts of the housing 2 through openings 36, the outer cylindrical the surface of these parts and the outer cylindrical surface of the outer protrusions of the elastic ring 6 is the same surface 37 along which the housing 2 (see Fig. 1) is tightened in the hub 1. The value of this interference is selected as small as possible, but such that with additional mounting of the housing 2 to the hub using bolts and self-locking nuts at all operating modes of the engine, the reliability of the housing-hub connection was ensured. The diameter of the inner cylindrical surface 38 of the cylindrical part of the housing 2 with the flange 32 is either equal to or greater than the diameter of the surfaces of the depressions 39 (see Fig. 4) between the inner protrusions 8 of the elastic ring 6. The diameter of the inner cylindrical surface 40 of the cylindrical part of the housing 2 with an inner shoulder 34 or equal to or less than the diameter of the outer surface of the inner protrusions 8 of the elastic ring 6. The interference between the outer ring 41 of the bearing 9 and the inner protrusions 8 of the elastic rings 6 (see Fig. 2) is 0 ÷ h / 2 mm, where h is the height of the protrusions of the elastic rings equal to h = 0.15 ÷ 0.3 mm. Two bores 42 with polished ends made of steel or bronze BrС30 are pressed into the bores made in the outer ring 41 of the bearing 9 on both sides of it (see Fig. 1). The ends of the gap between the hub 1 and the outer ring 41 of the bearing 9, in which the elastic rings 6 are located, are sealed with metal sealing rings 43, which are pressed by the polished ends to the polished ends of the bushings 42 with rubber sealing rings 44 located in the annular grooves in the shoulder 34 of the bearing housing 2 and the housing of the segment contact seal 22. On each metal sealing ring 43 (see Figs. 1 and 5), a protrusion 45 is made, which enters, respectively, in the return groove 46 (see Fig. 5), made in mouth 34 of the bearing housing 2 or the housing of the segmented contact seal 22 with a gap 47 around the perimeter of the groove less than the displacement of the metal sealing ring 43, at which mutual slippage of the metal 43 and rubber 44 of the sealing rings (see Fig. 1), and equal to 0 ÷ 0 , 05 mm. A variant with two protrusions and grooves in these details in FIG. not shown. At the ends of the outer ring 41 of the bearing 9 (see FIGS. 1 and 5), protrusions 48 are formed that are included in the response grooves 49 (see FIG. 5) of the metal sealing rings 43 with a gap 50 along the circumference of the groove 49 equal to or slightly larger than the permissible displacement pins 10 in the hub 1 with a gap of 0.15 ÷ 0.3 mm. The radial clearance 51 (see FIG. 1) between the metal o-rings 43 and the bearing housing 2 is less than the displacement of the metal o-rings, in which mutual slippage of the metal 43 and rubber 44 o-rings occurs, less than 0.1 mm. The radial distance from the outer circumference limiting the contact area of the rubber o-ring 44 with the metal o-ring 43 to the outer cylindrical surface of the metal o-ring 43 is such that the hydraulic pressure acting on each metal o-ring 43 from the side of the o-ring 44 balances disclosure of the joint between the metal sealing ring 43 and the outer ring 41 of the bearing 9 hydraulic pressure acting on and the metal sealing ring 43 from the side of the outer ring 41 of the bearing 9. For example, the radial distance of the metal sealing ring 43 in contact with the shoulder 34 of the bearing housing 2 is equal to or greater than half the radial size of the annular contact area of the sleeve 42, pressed into the outer ring 41 of the bearing 9, with a metal sealing ring 43, and on the other end of the bearing 9 it is larger than that described for h / 2. On the outer cylindrical surface of the metal sealing rings 43, two, three or more equally spaced circumferential through grooves 52 can be made of width 4 ÷ 5 mm and a height of 0.2 ÷ 0.5 mm. The metal sealing rings 43 are made of the same material as the bearing housing 2, and the hardness of their contact surfaces is less than the hardness of the contact surfaces of the bushings 42 pressed into the outer ring 41 of the bearing 9. Oil in the gap occupied by the elastic rings 6 (see Fig. 1 and 2), is fed through holes 53 and an annular groove 54 made in the hub 1 above the slots 36 located between the elastic rings 6 from a sealed container 55 made in the tide 56 on its outer surface. The oil supply pipe and plug sealing the container 55, in FIG. not shown. The number of holes 53 and their diameter are selected, possibly the smallest, but such that at all engine operating modes the cavities between the protrusions of the elastic rings are completely filled with oil 6. The housing of the segment contact seal 22 (see Fig. 1) is centered on the bearing housing 2 and is fixed to the flange 57 of the hub 1 with bolts 3, lock washers 4 and self-locking nuts 5, for which the flanges 32 and 58 of the bearing housing 2 and the housing of the segment seal 22 (see FIGS. 3 and 6) are made with troughs 59 evenly spaced along the periphery of the flanges, and at the hollows of one flange are offset from the hollows of the other flange so that the heads of the bolts 3 securing the bearing housing 2 are located in the hollows of the flange 58 of the housing of the segmented contact seal 22, and bosses 61 are made on the protrusions 60 formed by the hollows of the flange 58 of the housing of the segmented contact seal 22 (see Fig. 6), in the holes of which there are bolts 3 fastening this flange, and the height of these bosses is such that this housing with its flange 58 is pressed against the flange 32 of the bearing housing 2, and the bosses are pressed against the flange 57 of the hub 1. The joints between these all sealing flanges are interconnected with rubber o-rings 62 and 63 (see FIG. one). The inner diameter of the thread of the sleeve 14, mounted on the pin 10, is equal to or greater than the outer diameter of the inner ring 13 of the bearing 9, and the direction of winding of the threads is such that for a given direction of rotation of the fan, oil particles from the threaded connection of this sleeve and the ring 15 in contact with the segments 19 graphite o-rings 16 and 17 were thrown into the oil cavity 28, and the moment of friction acted on the ring 15 to screw it on, and the threaded joint itself was sealed with a rubber o-ring 64, placed m in the annular bores of the sleeve 14 and the ring 15. Between the ring 15 and the labyrinth ring 25 a split elastic ring 65 is installed, in the free state centered on the girdle of the labyrinth ring 25. The graphite O-rings 17 and 18 are inserted into each other without a gap, and the graphite O-ring 16 (see Fig. 1) is installed end-to-end to these two rings, and the joints of the segments 19 (see Fig. 7) of these rings in the circumferential direction are spaced from each other. The cylindrical surfaces of the graphite o-rings 17 and 18, on which they are in contact with each other, are made with an eccentricity of 1 ÷ 1.5 mm with respect to the cylindrical surface of the inner ring of this pair, on which it is in contact with the ring 15, screwed onto the sleeve 14. O-rings multilayer corrugated bags 20 are composed of “corrugations into corrugations” of polished steel tapes 66, cured or made of hardened stainless steel, and the joints of the ends of the tapes 66 are evenly distributed over the corrugation tops. Between the ends of each tape 66 there is a gap 67, the size of which is selected, possibly the smallest, but sufficient to avoid overlapping the ends of each tape against each other when creating an interference fit on the tops of the corrugations of the bags 20 and the maximum allowable radial displacement of the graphite o-rings. A wear-resistant coating is applied to the surface of the tapes 66, preferably silvering. The preferred thickness of the tapes is 66 h ₁ = 0.2 ÷ 0.4 mm. Packages of corrugated tapes 20 (see Fig. 3) with a radial tightness along the corrugation tops, created by equal simultaneous compression of all corrugations of each packet in radial directions, are inserted into the annular gap between the housing of the segment contact seal 22 and the graphite sealing rings 16 and 18 until they stop in the wall 68 (see Fig. 1) of this case, and the tops of the corrugations of the package are located in reciprocal recesses 69 (see Fig. 3) made in parts in contact with the packages in the form of segments with an arc of a circle of radius R, determined from the ratio and I:

where H ₁ is the maximum value of the additional displacement of the corrugation tip in the radial direction obtained by precessing the journal in the support with the maximum allowable displacement amplitude due to the displacement in the circumferential direction of the vertex of that corrugation in the recess that is maximally displaced in this direction, S ₁ is the half of the maximum chord displacements of this corrugation in the circumferential direction, and a chord notch, of a larger magnitude:

where H is the greatest depth of the excavation, less than 1 mm The maximum gap size 70 (see Fig. 3) in the corrugations of the corrugations, measured along the radius from its top to the part in contact with the package, is greater than the height of the protrusions of the elastic rings 6 (see Fig. 2). In the wall 68, holes or taps 71 are made (see Fig. 1) in places corresponding to the hollows of the corrugations. Between the wall 68 and the ring 15 in contact with the graphite sealing rings 16 and 17, there is an annular gap 72 greater than the allowable displacement of the ring 15 in the support. The segmented contact seal on the side of the pre-oil cavity 24 of the support is sealed by a cover 23 and rubber o-rings 73 located in the annular grooves of the cover. The cover 23 by elastic forces created by an elastic split ring 74 placed in the annular groove of the housing of the segment seal 22, and the pressure of the air entering the pre-oil cavity 24 of the support through the holes 30 in the pipe 26, axle 10 and the labyrinth ring 25, is pressed by the polished end to the polished response the ends of the graphite sealing rings 17 and 18. The housing of the segment seal 22 and the cover 23 are made of steel of the same grade or bronze BrС30, and the annular gap between the housing of the segment seal and the cover is also less than 0.1 mm. An end-to-end groove 75 is made in the cover 23 (see Fig. 8), into which, with a total clearance on the sides of the groove less than 0.1 mm, an emphasis 76 is inserted, which is hermetically sealed with a conical pipe thread and fixed in the housing of the segment seal 22 and locked with an elastic the ring 77. In the shoulder 34 (see Fig. 1) of the bearing housing 2, a throttle bore 78 is made, communicating with a gap along the perimeter of a groove 49 made in a metal sealing ring 43, or a throttle bore, communicating with a slot 36 in the middle cross section of the bearing housing 2, execution EHO in the outer ring 41 of the bearing 9 (Fig. not shown).

A front support for the rotor of a fan of a dual-circuit turbojet engine is also proposed, characterized in that the tops of the threads made on the sleeve 14 (see Fig. 1), on which a ring 15 is screwed onto it, in contact with the graphite o-rings 16 and 17, are cut flat, or the tops of the threads of a thread cut both on a sleeve 14 and on a ring 15 are cut flat.

The assembly of the proposed front support of the rotor of the fan of a dual-circuit turbojet engine is technologically quite simple and is described briefly without details.

All parts located in it are installed in the bearing housing 2 (see Fig. 1). A sealing rubber ring 62 is installed in the hub 1, and then a bearing housing 2 is installed with an interference fit and fastened to the hub 1 by bolts 3, washers 4 and self-locking nuts 5.

In the housing of the segmented contact seal 22 install all located in it parts. Moreover, multi-layer multi-span corrugated bags 20 are pre-assembled in a device (not shown in FIG.) And each corrugation of both packages is simultaneously radially compressed by sectors that are pushed apart by a punch made in the form of a truncated cone. Then, the packages 20 thus assembled (see Fig. 1) are pushed out of the device into the housing of the segmented contact seal 22 into the gap between the housing and the graphite sealing rings 16 and 18 assembled from the individual segments 19, against the stop in the wall 68 of the housing, and the segments 19 the elastic forces created by the packages 20, the ends are tightly pressed against each other, forming a continuous ring. An emphasis 76 with an elastic ring 77 mounted on it is wrapped in a segmented contact seal housing 22. A cover 23 with rubber sealing rings 73 installed therein is installed in the housing 22 until it stops at the ends of the graphite sealing rings 17 and 18, and an elastic groove is installed in the annular groove in the housing 22 split ring 74. In the case of the segmented contact seal 22, sealing rubber rings 44 and 63 and bolts 3, washers 4 and self-locking nuts 5 are mounted to the hub 1. In this case, the elastic split ring 74 compresses ripped apart in the axial direction and presses the cap 23 to the seal rings 17 and 18 and the entire packet graphite sealing ring to the wall of the housing 68 contact seal segment 22. This completes assembly of the stator unit support.

On the axle 10 install all located on it parts (see. Fig. 1) and fix it on the rotor of the fan (Fig. Not shown).

The stator assembly of the support is pushed onto the trunnion 10 with the assembled parts all the way into the fan housing and fastened to it (not shown in FIG.). At the same time, graphite sealing rings 16 and 17, composed of segments 19, are radially tightened on the ring 15 and gaps 21 equal to 0.05–0.1 mm appear between the ends of the segments 19.

The main aspects of the proposed support and its advantages compared to the prototype are discussed above.

Most of the vibrational energy of the fan rotor dissipated by the support is dissipated, as already indicated, during precessing of the axle 10 when oil is pressed through with large hydraulic losses through narrow throttle slots - troughs formed by the outer 7 and inner protrusions 8 of the elastic rings 6, from the troughs formed by the outer protrusions, into depressions formed by the inner protrusions, and, conversely, along the "long" path in the circumferential direction of the support.

There are known types of throttle dampers of turbomachine rotor bearings - with calibrated throttle holes (see prototype), with throttle grooves (see RF patent for invention 860566, IPC ³ F16F / 15/04. Hydrodynamic damper / ID Eskin, A.I. Belousov, D.K. Novikov, P.D. Vilner, E.A. Emelyanov, V.N. Snigirev. - Publish. March 20, 2001).

The damper of the proposed support, in our opinion, can be attributed to a completely new type of throttle dampers of the bearings of the rotors of turbomachines, namely, to the damper with narrow throttle slots.

In addition, the energy of the transverse vibrations of the fan rotor is dissipated due to hydraulic losses when squeezing oil out of the corrugations of the corrugations of the multilayer corrugated bags 20 and the dry friction forces work on mutual slippage during the precessing of the axle 10 of the inner protrusions 8 of the elastic rings 6 and the outer ring 41 of the bearing 9, bushings 42 and metal sealing rings 43, tapes 66 packets 20, the corrugation tops of the packets and parts in contact with them - the housing of the segment contact seal 22 and segments 19 of the graphite seal s rings 16 and 18, and also works to dry friction forces slippage graphite packing rings along the wall 68 of the housing 22 and cover 23.

The oil in the damper is constantly changed through the throttle hole 78.

The pre-oil cavity of the support 24 is vented (not shown in FIG.).

Among the advantages of the proposed support can also include the calculated stiffness of the elastic rings 6, the magnitude of the load pressing the segments 19 of the graphite sealing rings 16 and 17 to the ring 15, leaks through the sealing joints of the sealing graphite rings and the wear rate of their contact surfaces (see Lezhin D.S. Development of calculation methods and computer modeling of mechanical contact seals of multi-mode turbomachines. Thesis for the degree of candidate of technical sciences. Samara. - 2002).

In addition, modern editors designed to solve dynamic and static problems by the finite element method, for example, such as Ansys, contain the algorithms of all finite elements necessary to determine the hydrodynamic resistance forces of the throttle damper of the proposed support, and to construct loading processes of the multilayer corrugated packet 20 , leaks through the contact seal during the precession of the pin 10 in the support and solving the dynamic problem of forced oscillations of an unbalanced rotor tilyatora turbofan with the proposed front pillar.

In conclusion, we note that in the proposed front support of the turbofan engine rotor for sealing the oil cavity of the support, all currently known contact and non-contact seals can be used: mechanical contact seal (TKU), or radial-mechanical contact seal (RTKU), or gas-dynamic mechanical seal seal (TGDU).

Claims (2)

1. The front support of the rotor of the fan of a dual-circuit turbojet engine, comprising a hub, a bearing housing, two elastic elements connected in parallel so that their stiffnesses are summed, a roller bearing lubricated by bubbling, a trunnion, a figured bush mounted on a trunnion and fixing the inner ring of the bearing and flange rotating parts of the segment contact seal, segment contact seal, consisting of a sleeve with a thread fixed on a pin, a ring, three threads connected to this sleeve, Afitovy sealing rings, composed of separate segments, pressed to the ring in contact with them by two springs so that between the ends of the segments of these rings there is a gap of 0.05 ÷ 0.1 mm, two of which are inserted into each other without a gap, and the third ring is installed butt to these two rings, and the joints of the segments of these rings in the circumferential direction are spaced from each other, the labyrinth seal of the pre-oil cavity of the support, consisting of a labyrinth ring and a stator element, a pipe located inside the journal and forming an air a hollow cavity in it, and in the figured sleeve and trunnion holes are made through which oil is supplied to cool the ring in contact with graphite o-rings, characterized in that the bearing housing is integral with both elastic elements made in the form of elastic rings with uniformly alternating external and internal protrusions in such a way that its middle part is made in the form of these rings and the end cylindrical part of the body with a flange for attaching it to the hub and the other end part of the body with the inner collar are rigidly connected to these elastic rings along the length of each outer protrusion, and on the length of each inner protrusion and the adjacent two spans, each elastic ring is separated from these parts of the body through openings, the outer cylindrical surface of these parts and the outer cylindrical surface of the outer protrusions of the elastic the ring is one and the same surface along which the body with an interference fit is fixed in the hub, and the value of this interference fit is selected as small as possible, but such that with by securing the housing to the hub by means of bolts and self-locking nuts at all engine operating modes, the reliability of the housing – hub connection was ensured, and the diameter of the inner cylindrical surface of the cylindrical part of the housing with the flange was either equal to or greater than the diameter of the surfaces of the depressions between the inner protrusions of the elastic ring, and the diameter of the inner cylindrical surface of the cylindrical part of the housing with the inner shoulder is either equal to or less than the diameter of the outer surface of the inner protrusions of the elastic tsa, the tightness between the outer ring of the bearing and the inner protrusions of the elastic rings is 0 ÷ h / 2 mm, where h is the height of the protrusions of the elastic rings equal to h = 0.15 ÷ 0.3 mm into the bores made in the outer ring of the bearing on both of its sides, two bushings with polished ends, made of steel or bronze BrС30, are pressed in, and the ends of the gap between the hub and the outer ring of the bearing, in which the elastic rings are placed, are sealed with metal sealing rings that are pressed by the polished ends to the polished ends of these bushings p rubber rings located in the annular grooves in the shoulder of the bearing housing and the housing of the segment contact seal, and on each metal sealing ring there is one or two rectangular protrusions located on its diametrically opposite halves, which respectively enter the mating grooves made in the shoulder of the bearing housing or a housing of a segmented contact seal with a gap along the perimeter of the groove less than the displacement of the metal sealing ring, at which there are mutual slippages of the metal and rubber o-rings, and equal to 0 ÷ 0.05 mm, and at the ends of the outer ring of the bearing there are protrusions included in the mating grooves in the metal o-rings with a gap around the groove perimeter equal to or slightly larger than the permissible offset of the journal in the hub and equal to 0.15 ÷ 0.3 mm, and the radial clearance between the metal sealing rings and the bearing housing in the case of one rectangular projection on each metal sealing ring is less than the displacement of the metal the sealing ring, in which mutual slippage of the metal and rubber sealing rings occurs, is less than 0.1 mm, and in the case of two rectangular protrusions - less than 0.2 mm, and the radial distance from the outer circumference, limiting the contact zone of the rubber sealing ring with metal O-ring to the outer cylindrical surface of the metal O-ring is such that the hydraulic pressure acting on each metal O-ring with the torons of the sealing rubber ring, if the joint between the metal sealing ring and the outer ring of the bearing opens, the hydraulic pressure acting on the metal sealing ring from the side of the outer ring of the bearing is equal to or more than half the radial distance of the metal sealing ring in contact with the shoulder of the bearing housing radial size of the annular contact area of the sleeve, pressed into the outer ring of the bearing, with a metal seal an integral ring, and on the other end of the bearing it is larger than that described for h / 2, and on the outer cylindrical surface of the metal sealing rings two, three or more equally spaced circular grooves 4–5 mm wide and 0.2–0.0 mm wide can be made , 5 mm, metal O-rings are made of the same material as the bearing housing, and in the manufacture of bushings pressed into the outer ring of the steel, the hardness of the contact surfaces of the metal O-rings is less than reaching the contact surfaces of the bushings, and the oil in the gap occupied by the elastic rings is fed through holes and an annular groove made in the hub over the slots located between the elastic rings from a sealed container made in the tide on its outer surface, the number of holes made in the hub , and their diameter is chosen as small as possible, but such that in all engine operating modes the cavities between the protrusions of the elastic rings are completely filled, and the housing of the segment contact seal is centered I’m mounted on the bearing housing and fastened to the hub flange with bolts, lock washers and self-locking nuts, for which the bearing housing flanges and the segment seal housings are made with cavities evenly distributed on the periphery of the flanges, and the cavities of one flange are offset from the cavities of the other flange so that the bolt heads, securing the bearing housing are located in the hollows of the flange of the housing of the segmented contact seal, and bosses are made on the protrusions formed by the hollows of the flange of the housing of the segmented contact seal , in the holes of which there are bolts holding this flange, and the height of these bosses is such that this housing is pressed with its flange to the bearing housing flange, and the bosses to the hub flange, and the joints between all of these flanges are sealed with rubber o-rings, and the internal diameter of the thread of the sleeve mounted on the pin is equal to or greater than the outer diameter of the inner ring of the bearing, and the direction of winding of the threads is such that for a given direction of rotation of the fan, oil particles from the threaded connection of this sleeve and rings in contact with graphite o-rings made up of individual segments were thrown into the oil cavity, and the moment of friction acted on this ring to screw it on, and the threaded joint was sealed with a rubber o-ring placed in the annular bores of the sleeve and the ring, and between the ring and a labyrinth ring installed split elastic ring, in the free state centered on the belt of the labyrinth ring, the cylindrical surface of two graphite rings inserted each the other, on which they contact, are made with eccentricity with respect to the cylindrical surface of the inner ring of this pair, along which it contacts the ring screwed onto the sleeve, and two springs are applied as springs pressing the segments of the graphite sealing rings to the ring in contact with them annular multilayer corrugated bags assembled “corrugations into corrugations” of brushed steel cured tapes or tapes made of hardened stainless steel, and the joints of the ends of the tapes are evenly distributed on the corrugation tops, and between the ends of each tape there is a gap, the size of which is selected as small as possible, but sufficient to eliminate overlapping ends of each tape on each other when creating an interference fit on the tops of the corrugations of the bag and the maximum allowable radial displacement of graphite o-rings, and on the surface of the tapes wear-resistant coating, each packet of corrugated tapes with a radial interference over the corrugated vertices created by the same simultaneous compression of all the corrugations of the packet in radial directions is inserted into The front gap between the housing of the segmented contact seal and the graphite sealing ring on which it rests, against each other and into the wall of this housing so that its vertices are located in reciprocal recesses made in parts in contact with the packages in the form of segments with an arc of a circle radius R, determined from the relation:

where H ₁ is the maximum value of the additional displacement of the corrugation tip in the radial direction obtained by precessing the journal in the support with the maximum allowable displacement amplitude due to the displacement in the circumferential direction of the vertex of that corrugation in the recess that is maximally displaced in this direction, S ₁ is the half of the maximum chord displacements of this corrugation in the circumferential direction, and a chord notch, of a larger magnitude:

where H is the greatest depth of the recess, less than 1.5 mm, and the maximum size of the gap in the hollows of the corrugations, measured along the radius from its top to the part in contact with the package, is greater than the height of the protrusions of the elastic rings, and holes or recesses are made in the wall in places corresponding to corrugation hollows, and between the wall and the ring in contact with the graphite o-ring, made up of separate sectors, there is an annular gap greater than the permissible displacement of the ring in the support, and a segmented contact seal on the side of the pre-oil cavity and the supports are closed by a lid and sealed with rubber o-rings located in the annular grooves of the lid, and the lid and the segment seal housing are made of steel of the same grade or BrC30 bronze, and the annular gap between the segment seal housing and the cover is also less than 0.1 mm, and in the lid a non-through groove is made, in which, with a total clearance on the sides of the groove less than 0.1 mm, an emphasis is included, which is hermetically sealed with a conical pipe thread fixed in the housing of the segment seal and locked by an elastic the ring and the cover by elastic forces created by an elastic split ring placed in the annular groove of the segment seal housing and the pressure of the air entering the pre-oil cavity of the support through the holes in the pipe, trunnion and labyrinth ring, is pressed by the polished end to the mating polished ends of the graphite sealing rings, and in the shoulder of the bearing housing a throttle hole is made, communicating with a gap around the perimeter of the groove made in the metal sealing ring, or in the outer ring of the bearing is made o throttle bore, communicating with a slot in the middle cross section of the bearing housing. 2. The front support of the rotor of the fan of a dual-circuit turbojet engine according to claim 1, characterized in that the tops of the threads of the thread made on the sleeve, on which the ring in contact with the graphite o-rings is screwed on it, are cut flat, or the tops of the threads of the thread cut both on the sleeve and on the ring.

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