RU2579646C1 - Elastic damper rotor support turbomachinery - Google Patents

Abstract

FIELD: motors and pumps.

SUBSTANCE: elastic damper support of the gas turbine engine (GTE) GTE refers to aviation and land use, namely the construction of the compressor GTE elastic damper support. Support comprises body (1) mounted on rotor (2) rolling bearings (3), sleeve (4) fixed on housing (1) having internal shoulder (5), damper gap (6), sealed at the ends, nozzle ring (10) for supplying lubricant to bearing (3) mounted on housing (1) radially-mechanical contact seal in the form attached to rotor hub (14), a graphite seal of split ring (15), cover (16), rings (18 ) labyrinth seal mounted on rotor (2). Gap (6) is formed by external bearing ring (3) and sleeve (4). Ends of gap (6) sealed by metal sealing rings (7) and pressed against the ends of outer bearing ring (3) mating polished ends (8), rubber seals (9) arranged in annular grooves of ring (10) and piles (5). On rings (7) are one or two rectangular lugs (21) which include counter groove (22) formed in ring (10) and clamp (5) with gap (23) around the perimeter of the groove, the smaller displacement of ring (7) at which there are mutual slip rings (7) and (9), for example with a clearance of 0÷0.05 mm. Outer ring of bearing (3) projection (24) belongs to the reciprocal of blind groove (25) in ring (7) with gap (26) around the perimeter of the groove equal to or slightly larger than gap (6), for example with a clearance of 0.15÷0.2 mm. Radial gap (27) between rings (7) and sleeve (4) in the case of performing one rectangular projection at each metallic sealing ring is less than or equal to 0.1 mm, and in the case of performing two rectangular protrusions - less than or equal to 0.2 mm . Oil in ring (10) and gap (6) is supplied at a supply pressure of individual sealed cavities (28) in the casing tightness which ensures an interference fit between hub (4) and housing (1), the value of which is chosen such that a certain amount of this interference It retained at operating temperatures elastic damper support.

EFFECT: creating designs of elastic damper support the rotor of a turbomachine with smaller radial dimensions, higher elastic-damping properties and sealed with a substantially greater operating time to replace them.

2 cl, 6 dwg

Description

The elastic damper support of a gas turbine engine (GTE) refers to the GTE of aviation and ground applications, namely, to the design of the elastic-damper support of the GTE compressor.

Known elastic damper support for a gas turbine engine (see RF patent for utility model No. 92696, IPC F01D 25/16. Elastic damper support for a gas turbine engine. Volchenkova EG, Bukreev AN, Internet, file 92696. html) containing a bearing the outer ring of which is attached to the shell connected to the stator element using a split sleeve, forming with it a damping cavity bounded by seals. The shell is provided with a restrictive element made in the form of protrusions installed with a gap in the reciprocal grooves of the stator element, while the protrusions of the shell and grooves of the stator element are placed in the axial direction, and plates are rigidly attached to the side surfaces of the grooves.

The disadvantages of this elastic damper support are its large dimensions both in the axial and in the radial directions, obtained due to the presence of a shell and a split sleeve in the support structure. In addition, rubber sealing rings are used as a seal for the damping cavity in the bearings of the aircraft engine rotors, which during precession of the rotor slip with dry friction along the stator element, which leads to their wear and, therefore, to the need for their multiple replacement when the engine runs out of life.

Also known is the elastic damper support of a gas turbine engine (RF Patent for the invention RU 2151896 C1, IPC 7 F02C 7/06. Gas turbine engine support. V. Kuznetsov, patent holder: Aviadvigatel OJSC. Publish. 06/27/2000), containing the bearing housing, a cover mounted on the housing that separates the oil cavity of the support, a rolling bearing mounted on the rotor, a damper placed between them from two bushings concentrically arranged with a clearance, one of which is fixed in the housing and the other on the outer ring of the bearing, nozzles for supplying lubricant to the ipnik fixed on the housing, radially-contact mechanical seal as a sleeve mounted on the shaft, the sealing split graphite ring cap fixed to the bearing, the labyrinth seal. The ends of the damper clearance are sealed with split metal sealing rings located in the annular grooves on the outer surface of the sleeve mounted on the outer ring of the bearing. Oil is supplied under pressure from the cavity in the housing to the damper gap and to the nozzles. Each of the bushes of the support is made in one piece with an elastic element of the "squirrel wheel" type, which are fastened to each other by the ends.

Among the disadvantages of this elastic-damper support are its large dimensions in the radial and axial directions and the fact that the damper gap through the cavity in the housing is connected with nozzles by a path with a small hydraulic resistance, which leads to a significant decrease in the elastic-damper properties of the damper.

In addition, split metal O-rings are subject to wear, since during precession of the rotor they slip with dry friction along the sleeve fixed in the housing, which leads to the need for their multiple replacement when the resource is exhausted by the engine.

This elastic-damping support in technical essence is the closest to the proposed and adopted as a prototype.

The task is to create an elastic-damper support for the rotor of a turbomachine with radial dimensions smaller than that of the prototype, higher than that of it, elastic-damping properties and seals with significantly greater operating time before replacing them.

The problem is solved in that an elastic damper support for a gas turbine engine is proposed, comprising a housing, a rolling bearing mounted on the rotor, a sleeve mounted on the housing, having an inner shoulder, a damper gap sealed at the ends, an injector ring for supplying lubricant to the bearing mounted on the housing, radial-mechanical contact seal in the form of a sleeve mounted on the rotor, a sealing split ring, a cover, a labyrinth seal ring mounted on the rotor, characterized in that Mpfer clearance is formed by the outer ring of the bearing and the sleeve fixed in the housing, the ends of the gap are sealed with metal sealing rings made of the same material as the sleeve, and pressed against the ends of the outer ring of the bearing by the polished ends of the rubber sealing rings located in the annular grooves of the nozzle ring and in the collar of the sleeve, one or two rectangular protrusions located on diametrically opposite halves of the each metal o-ring, which are included in the mating grooves made in the nozzle ring and the collar collar with a gap along the perimeter of the groove less than the displacement of the metal o-ring, in which mutual slippage of the metal and rubber o-rings occurs, for example, with a gap of 0 ÷ 0.05 mm and a protrusion is made on the outer ring of the bearing, which enters the reciprocal non-through groove in the metal sealing ring with a gap around the circumference of the groove equal to or slightly larger than the damper gap, for example p with a gap of 0.15 ÷ 0.2 mm, and the radial clearance between the metal o-rings and the sleeve mounted on the housing, in the case of one rectangular projection on each metal o-ring, is less than or equal to 0.1 mm, and in the case of two protrusions - less than or equal to 0.2 mm, the hardness of the material of the metal o-rings is less than the hardness of the material of the outer ring of the bearing, and the oil enters the nozzle ring and damper clearance under the supply pressure from individual sealed cavities in the housing, g The tightness of which is ensured by the interference between the sleeve and the housing, the value of which is chosen such that a certain value of this interference is maintained at the working temperatures of the elastic damper support.

The implementation of the annular grooves for the sealing rings and ensuring the strength of the sleeve, fitted with an interference fit on the outer ring of the bearing, leads to the prototype that the radial dimension of the cross section of the wall of the sleeve is 8 ÷ 9 mm

It is two such radial dimensions that the inner diameter of the housing of the proposed support is reduced, along which the sleeve is fixed in it.

Inadmissible wear of metal O-rings is achieved over a period of time, many times greater than the period of time during which unacceptable wear of split metal O-rings in the prototype is achieved, due to the fact that the contact area is several times larger and the contact pressure is several times less . At the proposed elastic damper support, the time interval between routine maintenance on the support is determined by the aging time of the rubber of the sealing 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 the metal sealing rings of the proposed elastic damper support can be increased by applying to their surface in contact with the outer ring of the bearing a wear-resistant coating, for example, solid lubricant or silver.

The lower hardness of the material of the metal O-rings compared to the hardness of the material of the outer ring of the bearing reduces the wear of this ring.

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.

When performing metal o-rings with one rectangular protrusion, the radial clearance between them and the sleeve fixed in the 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 rectangular protrusions on each metal o-ring when choosing the size of this gap, there is no need to take this condition into account and the range of permissible radial clearance values is chosen to be large (less than or equal to 0.2 mm) and such 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 oil supply of the nozzle ring and the damper gap of each of its sealed cavities significantly increases the damping ability of the proposed elastic damper support of the turbomachine rotor.

In addition, in order to increase the reliability of the seal of the damper gap, to exclude the possibility of the damper gap with open sealing joints on the operating modes of the turbomachine, an elastic-damper support of the rotor of the turbomachine is proposed, characterized in that the outer diameter of the sealing rubber rings is chosen such that the radial distance from the outer circumference the contact area of the rubber o-ring with the metal o-ring, to the outer cylindrical surface of the metal of the sealing ring is equal to or less than half of the radial size of the annular contact zone of the metal sealing ring with the outer bearing ring, and two, three or more through rectangular grooves 4–5 mm wide and several tenths wide are arranged on the outer cylindrical surface of the metal sealing rings fractions of a millimeter, for example 0.2 ÷ 0.5 mm.

If the sealing joint opens between the metal sealing ring and the outer ring of the bearing and oil enters 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 in the end sections of the damper gap, and in the gap between the metal sealing ring and the nozzle and the same ring and the collar collar in the area from the outer circumference, limiting the contact area of the rubber seal to the ring of 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 in the above manner and concentric with respect to the axis of the rotor of the rubber rings, the resultant hydraulic 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 rubber o-ring.

The presence of gaps between the metal sealing ring and the nozzle ring or the collar collar on the outside of the rubber sealing ring, in which there is no cavitation zone and hydraulic pressure everywhere is greater than zero, and through grooves on the outer cylindrical surface of the metal sealing rings connecting the damper gap to these gaps, makes it difficult the appearance and expansion of cavitation zones in the damper gap and thereby improves the elastic-damping properties of the damper and, therefore, the elastic mod Fern support and the whole GTD.

The possibility of using rubber o-rings with an outer diameter at which the radial distance from the outer circumference, which limits the contact area of the rubber o-ring with the metal o-ring to the outer cylindrical surface of the metal o-ring, is less than half the radial size of the annular contact zone of the metal o-ring with the outer bearing ring all the fact that the working, cruising and maximum modes of operation of the gas turbine engine the extruded film damper operates in the “half-film” mode, when in the damper gap in the cavitation zone approximately 180 ° wide, the hydraulic pressure can be taken equal to zero. As already indicated, in the gap between the metal sealing ring and the nozzle ring or the collar collar outside the sealing rubber ring, there is no cavitation zone and the hydraulic pressure in it is everywhere greater than zero. Therefore, at these operating modes, the sealing joints will be closed and at a specified distance less than half the radial size of the annular contact zone of the metal sealing ring with the outer bearing ring.

The use of rubber sealing rings with a specified outer diameter in some cases may be useful, as it will provide more comfortable working conditions for the bearing and eliminate the possibility of burning in it.

The proposed design of elastic-damping bearings of the rotor of the turbomachine is illustrated by figures, where the rotor of the turbomachine is shown by a thin solid line as a “situation” in the assembly drawing.

In FIG. 1 shows a longitudinal section of the elastic damper support of the rotor with RTKU.

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

In FIG. 3 is a view according to page B in FIG. 1. Details of the RTKU are not shown.

In FIG. 4 is a view along page B in FIG. one.

In FIG. 5 shows a section along G-D in FIG. one.

In FIG. 6 shows a longitudinal section of an elastic damper of a rotor with an outer diameter of rubber o-rings such that the radial distance from the outer circumference that defines the contact area of the rubber o-ring with the metal o-ring and the outer cylindrical surface of the metal o-ring is less than half the radial size of the annular contact area of the metal o-ring rings with an outer ring of the bearing.

The proposed elastic damper support for a gas turbine engine (see Fig. 1) comprises a housing 1, a rolling bearing 3 mounted on the rotor 2, a sleeve 4 mounted on the housing 1, having an inner shoulder 5, a damper gap 6, sealed at the ends by metal sealing rings 7 made from the same material as the sleeve 4, and pressed against the ends of the outer ring of the bearing 3 by the mating polished ends 8 of the rubber sealing rings 9 located in the annular grooves of the nozzle ring 10 and in the shoulder 5 of the sleeve 4, fix on the housing 1 together with the sleeve 4 with studs 11, nuts 12 and lock washers 13 and the nozzle ring 10 centered in the sleeve 4 for supplying lubricant to the bearing 3 and to the radial-mechanical contact seal (RTKU), RTKU in the form of fixed on the rotor 2 and a sleeve 14 rotating with it, a sealing split ring 15 made of graphite, a cover 16, which serves as a RTKU stator, mounted on the housing 1 and centered on the flange 17 of the sleeve 4, the secondary labyrinth seal formed by the cover 16 and the labyrinth ring 18, fixed nym on the rotor 2 and rotates with it. The sealing split ring 15 is pressed against the sleeve 14 and the cover 16 by the pressure of the compressed air supplied through the hole 19 in the ring 18. The cover 16 forms an oil cavity 20. The damper clearance 6 (see FIGS. 1 and 2) is formed by the outer bearing ring 3 and the sleeve 4. On the metal sealing rings 7, rectangular protrusions 21 (see FIG. 1) are made, which enter the mating grooves 22 made in the nozzle ring 10 (see FIG. 3) and the collar 5 of the sleeve 4 (see FIG. 4) with a gap 23 around the perimeter of the groove less than the displacement of the metal sealing ring 7, at Hur arise mutual slippage metal 7 and a rubber O-ring 9, for example with a clearance of 0 ÷ 0,05 mm. A protrusion 24 is made on the outer ring of the bearing 3 (see Figs. 1 and 5), which enters the reciprocal non-through groove 25 in the metal sealing ring 7 with a gap 26 along the perimeter of the groove 25, equal to or slightly larger than the damper gap 6, for example, with a gap of 0, 15 ÷ 0.2 mm. The radial clearance 27 between the metal o-rings 7 and the sleeve 4 (see Fig. 1) is less than the displacement of the metal o-rings 7, in which mutual slippage of the metal 7 and rubber 9 o-rings occurs, for example less than or equal to 0.1 mm The hardness of the material of the metal sealing rings 7 is less than the hardness of the material of the outer ring of the bearing 3. Oil under the supply pressure enters from the sealed cavity 28 in the housing 1 through the hole (or holes) 29 in the sleeve 4 (see Fig. 1) into the groove 30 in the nozzle ring 10 (see Fig. 3), occupying the sector where the nozzles 31 are located, and from it through the openings 32 and 33 in the nozzles 30 (see Fig. 1) into the bearing 3 and onto the conical surface of the sleeve 14 of the RTKU, where from under the action of centrifugal forces enters through the hole 34 in the sleeve 14 to the grease tight a poke between the sleeve 14 and the sealing split ring 15. Oil is supplied to the damper gap 6 (see FIGS. 1 and 2) from the sealed cavity 35 in the housing 1, through an annular groove 36 made on the outer surface of the sleeve 4, and the holes 37 equally distributed around the circumference. The number of holes 37 is selected from the condition of full filling with an oil film at a given supply pressure of the entire damper gap in the operating modes of the turbomachine, where there is no rupture of the oil film, and the entire sector of the damper gap in which there is no rupture of the film, in modes with a rupture of the oil film, for example, operating modes of the turbomachine when the damper operates in the “half-film” mode. The value s of the damper gap 6 in the elastic damper bearings of the rotors of the turbomachines with compressive film dampers is selected from the range of 0.15≤s≤0.2 mm, with the size s = 0.15 mm being preferred. The tightness of the cavities 28 and 35 (see Fig. 1) is ensured by an interference fit between the sleeve 4 and the housing 1, the value of which is chosen such that a certain value of this interference is maintained at the working temperatures of the elastic damper support, and the sealing rubber ring 38. The tightness of the groove 30 of the nozzle ring 10 is provided by a rubber sealing ring 39 and an interference fit between the nozzle ring 10 and the inner surface of the sleeve 4. Moreover, this interference will decrease on the operating modes of the turbomachine, since the nozzle ring 10 is made INDICATES of titanium, and the sleeve 4 of steel and the thermal expansion coefficient of titanium is less than that of steel. The tightness of the oil cavity 20 is provided by the RTKU and the rubber sealing ring 40. The volume of the oil cavity 20 is made large, as foamed oil is pumped out of it. The housing 1 is made of a magnesium alloy and the coefficient of thermal expansion of this alloy is significantly greater than that of the steel of which the sleeve 4 is made, therefore the interference between the sleeve 4 and the housing 1 is significantly weakened in the operating modes of the turbomachine and the additional fastening of the sleeve 4 to the housing 1 with pins 11, nuts 12 and lock washers 13 provides in these modes the strength and reliability of the connection of the sleeve 4 with the housing 1.

A support variant with metal sealing rings with two rectangular protrusions is not shown in the figures.

In addition, an elastic damper support of the rotor of the turbomachine is proposed (see Fig. 6), characterized in that the outer diameter of the rubber sealing rings 9 in contact with the metal sealing rings 7 is chosen such that the radial distance from the outer circle bounding the contact area of the rubber sealing ring 9 with a metal sealing ring 7, to the outer cylindrical surface of the metal sealing ring is equal to or less than half the radial size of the annular contact zone of an all-round sealing ring 7 with an outer ring of the bearing 3, and on the outer cylindrical surface of the metal sealing rings 7, two three or more through circular grooves 41 are equally spaced around the circumference 41 4-5 mm wide and a few tenths of a millimeter high, for example 0.2-0 5 mm.

The assembly technology of the proposed elastic damping supports is clear from the structure of the support and is not specifically described.

When the rotor 2 is precessed (see Fig. 1), the bearing 3 will precessively move in the damper gap 6. In this case, the oil from the high pressure zone will be squeezed out in the gap 6 into the low pressure zone, flowing mainly in the circumferential direction - along the “long” paths with high hydraulic resistance, due to which the proposed supports will have very high elastic-damping characteristics. Oil change in the damper gap 6 during the operation of the turbomachine will occur constantly - in the low pressure zone, oil from the groove 36 through the holes 37 enters the damper gap 6 and flows out of it through the gap 26 along the perimeter of the groove 25 in the metal sealing ring 7. Other operating features and The advantages of the proposed elastic damping supports are discussed above.

Note that all the proposed fundamental distinguishing features that appear in the claims after the word “different” can be used without difficulty in a wide range of known designs of supports for rotors of turbomachines, for example, with radial and angular contact ball bearings, bearings with labyrinth seals in the oil zone supports, etc.

Claims (2)

1. An elastic damper support for a gas turbine engine, comprising a housing mounted on a rotor of a rolling bearing, a sleeve mounted on the housing having an internal collar, a damper gap sealed at the ends, an injector ring for supplying lubricant to the bearing mounted on the housing, a radial-mechanical contact seal in the form of a sleeve fixed to the rotor, a graphite sealing split ring, a cover, a labyrinth seal ring mounted on the rotor, characterized in that the damper gap is formed by an external ring The bearing ends and the sleeve fixed in the housing, the ends of the gap are sealed with metal sealing rings made of the same material as the sleeve, and pressed against the ends of the outer ring of the bearing by the response polished ends of the rubber sealing rings located in the annular grooves of the nozzle ring and in the collar of the sleeve , one or two rectangular protrusions located on diametrically opposite halves of each metal sealing ring are made on metal sealing rings rings that enter the reciprocal grooves made in the nozzle ring and the collar of the sleeve with a gap around the perimeter of the groove less than the displacement of the metal o-ring, at which mutual slippage of the metal and rubber o-rings occurs, for example, with a gap of 0 ÷ 0.05 mm, and the outer ring of the bearing has a protrusion that enters the reciprocal non-through groove in the metal sealing ring with a gap around the circumference of the groove equal to or slightly larger than the damper gap, for example, with a gap of 0.15 ÷ 0.2 mm, and a radial gap p between the metal sealing rings and the sleeve mounted on the housing, if one rectangular protrusion is made on each metal sealing ring, it is less than or equal to 0.1 mm, and if two rectangular protrusions are made, it is less than or equal to 0.2 mm, the material hardness metal O-rings are less than the hardness of the material of the outer ring of the bearing, and the oil enters the nozzle ring and the damper gap under the supply pressure from individual sealed cavities in the housing, the tightness of which is about It is ensured by an interference between the sleeve and the housing, the value of which is chosen such that a certain value of this interference is maintained at the working temperatures of the elastic damper support. 2. The elastic-damper support of the rotor of the turbomachine according to claim 1, characterized in that the outer diameter of the sealing rubber rings is chosen such that the radial distance from the outer circumference, which limits the contact area of the rubber sealing ring with the metal sealing ring, to the outer cylindrical surface of the metal sealing ring is equal to or less than half the radial size of the annular contact zone of the metal sealing ring with the outer ring of the bearing, and on the outer cylindrical On the surface of the metal sealing rings, two three or more through rectangular grooves 4–5 mm wide and several tenths of a millimeter wide, for example 0.2–0.5 mm, are equally spaced around the circumference.

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