FR2657119A1 - IMPROVED ARRANGEMENT FOR SEALING INTERSTICES SEPARATING ADJACENT CIRCUMFERENTIAL SEGMENTS FROM TURIENTS AND TURBINE REINFORCEMENT RINGS. - Google Patents

Abstract

An arrangement for sealing a gap (50) defined between the spaced ridges of two adjacent segments (54) includes two opposing slanted rims (66) on the edges of the segments, having oppositely sloped planar surfaces (68) defined. on their top, a cylindrical sealing rod (70) resting on the rims, so as to cover and close the gap between the rims, and an elastic clamp (72) having in a cross section a shape resembling that of a canal. The clamp is anchored below the flanges and covers the rod so as to bias it to bring it into sealing contact with the flat surfaces of the flanges and to create a sealing relationship with the gap. The opposing side portions (72A) of the clip are hook-like in shape, one being the reverse of the other, to extend around and below the edges, while the middle portion (72B) of the clamp is in contact with the shank and has a configuration to conform to the shape of one side of the shank in contact with the middle part of the clamp. Application to the circumferential segments of the nozzles and reinforcement rings of the turbines of gas turbine engines.

Description

The present invention relates to gas turbine engines in general and,

  more particularly, an improved arrangement for sealing gaps between adjacent circumferential segments of turbine nozzles and reinforcing rings. The efficiency of a gas turbine engine is a function of many factors One of the factors is the degree to which the high-pressure cooling air produced by the compressor section of the gas turbine engine is intended primarily to drive its operation. turbine section, is taken for other uses in the engine One of the uses of this air is to cool the metal surfaces along the main flow path of the gas generator so as to keep them below the temperature of melting The greater the amount of cooling air spent on other jobs in the engine, the lower the amount of air used to drive the turbine, which results in less operation.

effective of it.

  Therefore, it is important to limit the amount of cooling air that is not used to

  driving the turbine to the absolutely necessary value

  to meet other auxiliary functions

  proposed in the prior art of the arrangements of

  In order to avoid the loss of air diverted into the interstices separating the adjacent segments of the engine components. Representative of prior art sealing devices are US Pat. Nos. 3,728,041. Nos. 4,311,432, 4,537,024, 4,662,658, 4,759,687, and 4,767,260. The tongue-like joint arrangement is known in the prior art as a sealing arrangement frequently used to seal a gap separating the edges. Adjacent segments of turbine nozzles and reinforcement rings An advantage of this arrangement is the simplicity of its construction. However, it constitutes an inefficient sealing mechanism because it is prone to leak when there is a geometry far less than to be optimum at the edges of the segments, for example as a result of machining processes employed, tolerances used, and movements in the absence of segment alignment As a result, there remains a need for an arrangement to effectively seal the interstices of the edges of the segments while avoiding the

problems just described.

  The present invention provides a perfective arrangement

  The purpose of the improved arrangement of the present invention is to maintain an effective seal across the gap formed between the edges of adjacent segments.

  while they suffer a limited displacement and

  lack of alignment with each other

  In view of these possibilities, the perfect arrangement

  This sealing arrangement is particularly suitable for sealing gaps between adjacent turbine nozzle segments and reinforcement rings where such relative movements and misalignment will occur as a result of expansion and thermal contraction.

segments.

  The sealing arrangement is therefore effective to prevent leakage of the cooling air passing through the

  interstices, and entering the main flow path.

  The present invention is applicable to all turbine engines employing segmented nozzles and cooled reinforcement rings. The efficiency of the turbine engine increases due to the better sealing of the engine. In addition, the arrangement provides improved wear characteristics and improved performance of the refrigerant in the improved arrangement of the present invention.

  improved cooling of the edges of the segments.

  Accordingly, an object of the present invention is an improved arrangement for sealing the gap separating the adjacent edges of segmented compounds which comprises: (a) a pair of inclined flanges being opposed on the edges of the segments having on their surfaces surfaces respective planar, inclined being opposite; (b) a sealing member disposed between the inclined plane surfaces of the flanges, sitting thereon, so as to cover and close the gap between the flanges and (c)

  an elastic clip anchored below the edges and covered

  the sealing member so as to urge it into sealing engagement with the flat surfaces of the

  flanges, in sealing relationship with the gap.

  More specifically, the resilient clip has a channel-like shape in a cross-section and includes a pair of opposing longitudinal side portions and a medial portion interconnecting the side portions. The opposing side portions of the clip are hook-shaped. one being the opposite of the other, to extend around and below the edges of the segmented components The middle part of the clip covers and is in contact with the sealing element and its shape matches that of one side of the sealing element that is in contact with

the middle part of the clamp.

  In addition, the sealing member is an elongate linear shank having rounded surfaces in contact with the flat surfaces of the rims of the edges of the segments. More specifically, the sealing rod has a cross-section of circular shape so as to create a substantially linear tight contact with the flat surfaces of the flanges.

  The following description refers to the figures

  FIG. 1 is a schematic view of a gas turbine engine, FIG. 2, a partial sectional view of a prior art sealing arrangement for sealing gaps between adjacent circumferential segments of nozzles and reinforcing rings of the turbine, FIG. 3, a partial perspective view of a

  improved sealing arrangement according to the present invention.

  Figure 4, an end view, on a large scale, of

  the improved sealing arrangement of FIG.

  In the following description, the same references

  designate identical or corresponding parts in

  all the views Moreover, in the following description, we

  understand that expressions such as "anterior", "posterior", "backward", "right", "upward", "downward", etc., are given as a convenience and

  not be considered as limiting.

  In the drawings, and more particularly in FIG. 1, there is shown as a whole by reference numeral 10 a gas turbine engine, to which the present invention can be applied. The motor 10 has a longitudinal axis A and comprises an annular housing 12 arranged co-axially and concentrically about the axis A The engine 10 comprises a gas generator 14, consisting of a compressor 16, a combustion chamber 18, and a high pressure turbine 20, or a stage or several stages, all these elements being arranged along the longitudinal axis A of the motor 10 in an axial flow relationship, serial A

  drive shaft 22 interconnects the compressor

  16 and the high pressure turbine 20.

  The gas generator 14 has the function of producing

  flue gases Pressurized air from the compressor

  16 is mixed with the fuel in the combustion chamber 18 and ignited, hence the production of the combustion gases Some work is extracted from the gases by the high pressure turbine 20, which drives the compressor 16 The rest of the combustion gases is discharged from the generator

  14 in a power turbine 24 at low pressure.

  The low pressure turbine 24 comprises a rotor 26 with an annular drum and a stator 28. The rotor 26 rotates on bearings 30 and comprises a multitude of rows of blades 34.

  extending radially outwardly and spaced axially

  The stator 28 is arranged radially

  outside the rotor 26 and comprises a plurality of rows of blades 26 fixed to the stationary housing 12 extending in the radial direction of its interior. The rows 36 of the stator vanes are axially spaced apart from one another. alternating with the rows 34 of the blades of the turbine The rotor 26 is fixed to a drive shaft 38 and interconnected to the drive shaft

  22 via differential bearings 32.

  The drive shaft 38 rotates an anterior auxiliary compressor rotor 39 which is part of an auxiliary compressor 40 and which also supports rows 41 of anterior fan blades housed within a nacelle 42 supported by the fixed casing 12 by a multitude of spacers 43, a single spacer being shown The auxiliary compressor 40 consists of a multitude of rows of fins 44, fixed to the rotor 39 of the compressor extending radially outwards in order to rotate with it and a multitude of rows 46 6 - compressor stator vanes attached to the housing 12 extending radially inwardly The rows 44 and 46 are spaced axially from each other and arranged

alternately.

  We will now describe a sealing arrangement of the

prior art.

  FIG. 2 shows an arrangement of

  which is often used in the prior art

  the invention, which is shown generally by reference numeral 48 and hereinafter referred to as a tongue-and-groove arrangement, for the purpose of preventing leakage of the cooling air between the outer refrigerant side 14 A and the flow path side The purpose of the arrangement 48 is to seal each interstice of a multitude of interstices 50 (only one of them is shown) between the adjacent edges 52 of a multitude of gaps. circumferential segments 54 (only a pair of segments is shown) including portions of

  nozzles and reinforcement rings (not shown entirely

  of the gas turbine engine 10.

  The gaps 50 constitute a path for cooling air leaks between the high-pressure outer side 14a and the low-pressure inner side 14B of the gas generator 14 The cooling air is generally conveyed at low speed and under high pressure to hit the impact baffles 56 overlying the segments 54 to be cooled While the air passes through orifices 58 formed in the baffles, it accelerates and strikes the outer side of the segments 54 at a higher speed, which increases the transfer of the

heat from the segments.

  To prevent cooling air from going through

  50, the arrangement 48 employs an element of

  60 linguiform cheetah, flat, elongated, thin.

  The element 60 is inserted by its opposite longitudinal edges 7 - A in grooves 62 formed in the edges 52 of the adjacent segments to cover the gap 50 between the edges and press sealingly on the surfaces.

Inner 62 has grooves 62.

  However, because of the inability to provide a common plane relationship between the grooves 62 of the edges 52 of adjacent segments, the arrangement 48 constitutes an ineffective sealing arrangement, which may leak. The inability to maintain the alignment of the grooves Adjacent 62 in the same plane is due to machining tolerances and movements of the segments The tongue-like sealing element 60 will therefore not sit properly in the grooves 62 and will not properly seal and it will result In addition, the grooves 62 are generally obtained by using an electric discharge machining method which causes a certain roughness of their surfaces, including the inner surfaces 62 A on which the element 60 rests roughness. lower surfaces 62 A thus contributes to the formation of a path

  for cooling air leaks.

  In the tongue-like sealing arrangement 48 the geometry at the edges 52 of the segments is difficult to cool

  effectively because of this difficulty of cooling

  and the increase in operating temperatures

  The edges 52 are capable of being oxidatively eroded from the turbine. The modifications to be made to the prior art tongue seal arrangement for the purpose of improving the cooling of the edges of the segments.

  are limited by this inherent geometry.

  The sealing arrangement will now be described.

  of the present invention.

  In FIGS. 3 and 4, there is shown the improved sealing arrangement, generally designated by the reference numeral 64, according to the present invention, which avoids the problems described above from which the arrangement 48 of the present invention The arrangement 64 comprises a pair of flanges 66, inclined in opposite directions, on the

  edges 52 circumferential segments 54 which are normally

  The flanges 66 define on their surfaces flat surfaces inclined in

  opposite directions, directed upwards.

  The sealing arrangement 64 also comprises a sealing element 70 which is preferably under the

  shape of an elongated cylindrical rod 70 extending generally

  The rod 70 is seated on the flat surfaces 68 of the inclined flanges 66 so as to cover and close the gap 50 separating the flanges. The circular shape in a cross section of the rod 70 and the orientation of the flat surfaces 68 that they are inclined in opposite directions, facilitate contact

  rectilinear sealing between the incur-

  70 A, distant from each other, from the rod 70 and the

flat surfaces 68.

  The sealing arrangement 64 further comprises an elastic clip 72 anchored beneath the flanges 66 and covering the rod 70 so as to urge it to bring it into a rectilinear sealing contact with the flat surfaces 68 of the flanges 66 and In addition, in FIG. 3, plates 74 are shown that are struck by the cooling air (the holes they comprise being omitted to make the figure clearer) that do not form part of the gap. of the sealing arrangement 64 of the

present invention.

  The elastic clip 72 has, in a transverse section

  1a, the shape of a channel and comprises two opposite longitudinal side portions 72A and a middle portion 72B interconnecting the portions 72A As seen in Figure 4, the portions 72A of the clamp 72 have the general shape of a hook, one of the parts being the opposite of the other 9-parts 72A extend around and below the flanges 66 of the segments 54 and are in contact with the lower surfaces 69 of the flanges at the ends of the parts 72 A for anchoring the gripper 72 The surfaces 69 are also substantially planar and substantially parallel to the surfaces

flat upper 68.

  The median portion 72 B of the clip 72 covers the upper side of the cylindrical rod 70 in contact with it. The portion 72 B has the shape of an arc in a cross-section so as to conform to the curved shape of the side.

  upper stem 70 where contact is made with it.

  The pint-e 72 flexes relatively easily and has a relatively low stiffness so that it does not exert

  that a load or slight stress on the rod 70.

  The flexibility of the resilient clip 72 holds the sealing rod 70 in the slot formed by the flat surfaces 68 of the flanges 66. The sealing arrangement is held relatively even while the flanges are relatively straight relative to each other. the other because the planes of the surfaces 68 will always cut off during the operation of the motor Therefore, the segments 54 can move radially or circumferentially to deviate from one another, or angularly, and the arrangement operates from In the same way as if there were maintaining a perfect alignment The bias, exerted downwards, by the clamp 72 on the rod 70 allows the rod to go up and down on the flanges 66 as they get closer or closer to each other. away from each other, which has the effect of

  to enlarge () u to narrow the gap 50, respectively.

  The lateral portions 72 A of the clamp can be slidably or fixedly supported on the lower surface

  69 flanges 66, depending on the operating conditions

  expected, and still maintain the arrangement of

  chéité. It will appear that the spring clip 72 and the sealing rod 70 do not need to have the same length.

  clip 72 may consist of short lengths.

  In addition, the shape, in a cross section of the clamp, can be varied to impart various values to the actuating force of the seal. In addition, the sealing surfaces of the flanges 66 can be made by grinding, providing a finish smoother surface for better sealing and a lower cost price The ends of the clamp can be coated with

  way to avoid air leaks to their right.

  we think we will understand the present invention and the

  most of its benefits by reading the description

  previous and that it will appear that one can make various changes in the form, construction and arrangement of parts without departing from the spirit and scope of the invention For example, the present invention is sealed , or can be easily adapted for this purpose, the gap separating adjacent segments, and not just

circumferential segments.

he -

Claims (15)

  An arrangement (64) for sealing a gap (50) between adjacent edges (52) of segmented components (54) having opposite planar surfaces (68) on top thereof, characterized in that it comprises: (a) a sealing member (70) disposed between, seated, the inclined plane surfaces of the edges of the segmented components to cover and close the gap separating the ridges, and (b) a resilient clip (72). anchored beneath the edges of the segmented components and covering the sealing member (70) so as to urge the sealing member (70) into sealing engagement with the flat surfaces of the   edges and in sealing relationship with the gap.   Arrangement according to claim 1, characterized in   the segmented components (54) comprise components   circumferentially segmented, and the elastic clip   (72) has two lateral, longitudinal, oppo-   (72 A) and a middle part (72 B) interconnecting the side parts.   3 Arrangement according to claim 2, characterized in that the opposite side portions (72 A) of the resilient clip have the shape of a hook, one being the opposite of the other to extend around and below edges of segmented components.   Arrangement according to Claim 2, characterized in that the middle part (72 B) of the clamp is in contact with the sealing element (70) and shaped to conform to the shape of one side of the element. sealing in contact with the middle part of the clamp.   Arrangement according to claim 1, characterized in that the sealing element is an elongated linear rod having rounded surfaces in contact with the surfaces plane of edges.   An arrangement according to claim 5, characterized in that the sealing rod has a circular cross-section to make the contact substantially linear.   sealing with the flat surfaces of the edges.   Arrangement according to claim 1, characterized in that the elastic clip (72) has a transverse section   dirty a shape resembling that of a channel.   Sealing arrangement in combination with two adjacent segments (54) spaced from one another and having spaced edges defining a gap (50) therebetween, characterized in that it comprises: (a) two flanges (66) on the edges of the segments having on their surfaces respective planar, inclined opposite surfaces (68); (b) a sealing member (70) disposed between the flanges and seated on the flat surfaces (68) so as to seal and seal the interstice separating the ridges, and (c) a resilient clip (72) anchored beneath the flanges and covering the sealing member so as to urge it into sealing engagement with the flat surfaces (68) of the flanges and form a sealing relationship with the gap (50).   Arrangement according to claim 8, characterized in   the gripper has lateral, longitudinal   opposite (72 A) and a middle part (72 B) intercon- nectant the side parts.   Arrangement according to claim 9, characterized in that the opposite side parts have a shape resembling that of a hook, one being the opposite of the other, to extend around and below the edges   (52) segmented components (54).   Arrangement according to claim 9, characterized in that the middle part (72 B) of the clamp is in contact with the sealing element (70) and shaped to fit the shape of one side of the element sealing in 13 -   contact with this middle part of the clamp.   Arrangement according to claim 8, characterized in that the sealing element is an elongated linear rod (70) having rounded portions of its surface which are in contact with the flat surfaces (68) of the flanges. Arrangement according to Claim 12, characterized in that the rod has a circular cross-section in a cross-section so as to make the straight line substantially straight.   sealing contact with the flat surfaces of the flanges.   Arrangement according to claim 8, characterized in that the clamp (72) has in a cross-section a   shape resembling that of a channel.   Sealing arrangement (64) in a gas turbine engine having a plurality of contiguously spaced apart segments (54) which define between them interstices (50) through which a pressurized gas can flow between the high pressure side and the low pressure side of the segments, characterized in that it comprises: (a) two flanges (66) inclined at opposite ends on   the segments, having respective planar surfaces, inclined   born opposite (68) which are defined on their top. (b) a sealing member (70) seated on the   flat surfaces inclined edges and covering the inter-   stice (50) between the edges to close it, and c) an elastic clip (72) anchored beneath the   flanges and covering the sealing element for the stress   ter and bring it into sealing contact with the flat surfaces (68) of the flanges, in order to close the gap (50) sealingly. Arrangement according to Claim 15, characterized in that the resilient clamp (72) has two opposite longitudinal longitudinal portions (72 A) and a portion 14 -   median (72 B) interconnecting the lateral parts.   An arrangement according to claim 16, characterized in that the opposite side portions of the resilient clip have a shape resembling that of a hook, one being the opposite of the other, so as to extend around and   below the edges of the segmented components.   Arrangement according to claim 16, characterized in that the middle part (72 B) of the clamp is in contact with the sealing element (70) and has a configuration   to fit the shape of one side of the watertight element   cheeks in contact with the middle part of the forceps.   Arrangement according to claim 15, characterized in that the sealing element is an elongated linear rod (70) having rounded portions of its surface   which are in contact with the flat surfaces of the flanges.   Arrangement according to Claim 19, characterized in that the cylindrical rod has a circular cross sectional shape in order to make the sealing contact substantially linear with the flat surfaces of the flanges.   Arrangement according to claim 15, characterized in that the elastic clip in a section   cross-section a shape resembling that of a channel.