Abstract
A turbomachine rotor blade includes a radially outer end equipped with a heel, the heel being provided with at least one sealing wiper, the or each sealing wiper projecting beyond the heel along a first axis, the first axis being at ±15° with respect to a radial direction, and extending along a second axis, substantially perpendicular to the first axis, between a first upper-surface end and a second lower-surface end, the or each sealing wiper having a first upstream side and a second downstream side as well as a radially outer surface, wherein the or each sealing wiper includes a base attached to the heel and an end piece removably interlocked with the base.
Claims
1. A turbomachine rotor blade comprising a radially outer end equipped with a heel, the heel being provided with at least one sealing wiper, the at least one sealing wiper projecting beyond the heel along a first axis, the first axis being at any angle from −15° to +15° with respect to a radial direction, and extending along a second axis, substantially perpendicular to the first axis, between a first upper-surface end and a second lower-surface end, the at least one sealing wiper having a first upstream side and a second downstream side as well as a radially outer surface, wherein the at least one sealing wiper comprises a base attached to the heel and an end piece removably interlocked with the base, the end piece having a plurality of male portions and, for each male portion of the end piece, the base having a corresponding female portion, each male portion of the end piece removably interlocking in said corresponding female portion of the base, wherein each male portion of the end piece is a cylindrical shape extending radially along the first axis when the end piece is interlocked with the base.
2. The turbomachine rotor blade according to claim 1, wherein the at least one sealing wiper comprises a wear indicator.
3. A turbomachine rotor comprising the turbomachine rotor blade according to claim 1.
4. A turbomachine comprising the turbomachine rotor according to claim 3.
5. A turbomachine rotor blade comprising a radially outer end equipped with a heel, the heel being provided with at least one sealing wiper, the at least one sealing wiper projecting beyond the heel along a first axis, the first axis being at any angle from −15° to +15° with respect to a radial direction, and extending along a second axis, substantially perpendicular to the first axis, between a first upper-surface end and a second lower-surface end, the at least one sealing wiper having a first upstream side and a second downstream side as well as a radially outer surface, wherein the at least one sealing wiper comprises a base attached to the heel and an end piece removably interlocked with the base, the end piece having a plurality of male portions and, for each male portion of the end piece, the base having a corresponding female portion, each male portion of the end piece removably interlocking in said corresponding female portion of the base to form a male-female connection between the end piece and the base to prevent rotation of the end piece relative to the base when the end piece is interlocked with the base, wherein each male portion of the end piece is a cylindrical shape extending radially along the first axis when the end piece is interlocked with the base.
Description
BRIEF DESCRIPTION OF THE FIGURES
(1) The figures are presented for indicative purposes and in no way limit the invention.
(2) FIG. 1 shows a schematic representation in perspective of a turbomachine rotor blade.
(3) FIG. 2a shows a schematic representation in perspective of a sealing wiper according to a first embodiment of a first aspect of the invention.
(4) FIG. 2b shows a schematic representation in perspective of a sealing wiper according to a second embodiment of the first aspect of the invention.
(5) FIG. 2c shows a schematic representation in perspective of a sealing wiper according to an alternative of the first embodiment of the first aspect of the invention.
(6) FIG. 3a shows a schematic representation in perspective of a sealing wiper according to a third embodiment of the first aspect of the invention.
(7) FIG. 3b shows a schematic representation in perspective of a sealing wiper according to a fourth embodiment of the first aspect of the invention,
(8) FIG. 4a shows a schematic representation in perspective of a sealing wiper according to a first embodiment of a second aspect of the invention.
(9) FIG. 4b shows a schematic representation according to a side view of the sealing wiper of FIG. 4a.
(10) FIG. 5 shows a schematic representation according to a top view of a first upstream sealing wiper and a second downstream sealing wiper according to the first embodiment of the second aspect of the invention.
(11) FIG. 6a shows a schematic representation in perspective of a sealing wiper according to a first alternative of a second embodiment of the second aspect of the invention.
(12) FIG. 6b shows a schematic representation in perspective of a sealing wiper according to a second alternative of the second embodiment of the second aspect of the invention.
(13) FIG. 6c shows a schematic representation in perspective of a sealing wiper according to a third alternative of the second embodiment of the second aspect of the invention.
DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT OF THE INVENTION
(14) Unless stated otherwise, a same element appearing in the different figures has a single reference.
(15) FIG. 1 shows a schematic representation in perspective of a turbomachine rotor blade 1. The blade 1 comprises a radially outer end equipped with a heel 2. Generally speaking, the heel of a blade, also called “plateau”, forms a surface substantially perpendicular to the blade; the set of all the contiguous heels forms a sealed crown. The heel 2 is equipped with at least one sealing wiper. In the example of FIG. 1, the heel 2 is equipped with a first upstream sealing wiper 3 and a second downstream sealing wiper 4. When the heel 2 is thus equipped with a plurality of sealing wipers, “upstream sealing wiper” is taken to mean the sealing wiper which is situated, among the plurality of sealing wipers, the furthest upstream. Similarly, “downstream sealing wipe” is taken to mean the sealing wiper situated, among the plurality of sealing wipers, the furthest downstream. Alternatively, the heel 2 could only be provided with a single sealing wiper, for example only the first sealing wiper 3, which could then be qualified both as “upstream” or “downstream”. Each sealing wiper 3, 4 projects from the heel 2 along a first axis {right arrow over (z)}. The first axis {right arrow over (z)} extends to plus or minus 15°, preferentially plus or minus 10° and more preferentially plus or minus 5° with respect to a radial direction, the radial direction being defined with respect to the axis of the rotor of the turbomachine. Each sealing wiper 3, 4 extends circumferentially along a second axis {right arrow over (x)} substantially perpendicular to the first axis {right arrow over (z)}, between a first upper-surface end 31, 41 and a second lower-surface end 32, 42. Finally, as is more particularly shown in FIGS. 4a and 5, each sealing wiper has a first upstream side 33, 43 and a second downstream side 34, 44, as well as a radially outer surface 35, 45.
(16) A first aspect of the invention will now be described, in relation with FIGS. 2a, 2b, 3a and 3b.
(17) According to the first aspect of the invention, the or each sealing wiper 3, 4 comprises a base 7 attached to the heel 2 and an end piece 8 removably interlocked with the base 7.
(18) FIG. 2a shows a schematic representation in perspective of the first sealing wiper 3 according to a first embodiment of the first aspect of the invention. FIG. 2b shows a schematic representation in perspective of the first sealing wiper 3 according to a second embodiment of the first aspect of the invention. FIG. 2c shows a schematic representation in perspective of the first sealing wiper 3 according to an alternative of the first embodiment of the invention.
(19) According to the first embodiment of the first aspect of the invention, the end piece 8 has a single male portion 80 and the base 7 has a single female portion 70 corresponding to the male portion 80, the male portion 80 removably interlocking in the female portion 70. The male portion is for example of parallelepiped shape but may alternatively have any other type of shape. In particular, according to the alternative of the first embodiment of the invention, the male portion 80 has an inverted T shape, with a first portion having an essentially radial extension, along the first axis {right arrow over (z)}, and a second portion having an extension essentially perpendicular to the first portion, along the third axis {right arrow over (y)}.
(20) According to the second embodiment of the first aspect of the invention, the end piece 8 has a plurality of male portions 81, 82, 83 and the base 7 has, for each male portion of the end piece 8, a corresponding female portion 71, 72, 73, each male portion removably interlocking in its corresponding female portion. Each male portion is for example of cylindrical shape but may alternatively have any other type of shape.
(21) An example of dimensioning, expressed as a function of the total height (along the first axis {right arrow over (z)}) of sealing wiper and valid both for the first and second embodiments is the following: height of the base 7: ⅔±10% of the total height of the sealing wiper; depth of the or each female portion 70, 71, 72, 73: ⅓±10% of the total height of the sealing wiper; height of the or each male portion 80, 81, 82, 83 projecting beyond the end piece 8: ¼±10% of the total height of the sealing wiper; height of the end piece 8 without the or each male portion 80, 81, 82, 83: ⅓±10% of the total height of the sealing wiper.
(22) FIG. 3a shows a schematic representation in perspective of the first sealing wiper 3 according to a third embodiment of the first aspect of the invention. FIG. 3b shows a schematic representation in perspective of the first sealing wiper 3 according to a fourth embodiment of the first aspect of the invention.
(23) According to the third embodiment of the first aspect of the invention, the single male portion 80 projects from the base 7 whereas the single corresponding female portion 70 is arranged in the end piece 8.
(24) According to the fourth embodiment of the first aspect of the invention, the plurality of male portions 81, 82, 83 projects from the base 7 whereas each corresponding female portion 71, 72, 73 is arranged in the end piece 8.
(25) An example of dimensioning, expressed as a function of the total height (along the first axis {right arrow over (z)}) of sealing wiper and valid for the third and fourth embodiments is the following; height of the end piece 8: ⅔±10% of the total height of the sealing wiper; depth of the or each female portion 70, 71, 72, 73 of the end piece 8: ⅓±10% of the total height of the sealing wiper; height of the or each male portion 80, 81, 82, 83 projecting beyond the base 7: ¼±10% of the total height of the sealing wiper; height of the base 7 without the or each male portion 80, 81, 82, 83: ⅓± 10% of the total height of the sealing wiper.
(26) According to each of the first, second, third and fourth embodiments of the first aspect of the invention, as well as according to the alternative of the first embodiment of the first aspect of the invention, the end piece may notably be tightly fitted in the base, and/or weld points may be formed between the end piece and the base in order to retain the end piece radially when the turbomachine is in rotation and when a centrifugal force is exerted thereon. According to the alternative of the first embodiment of the invention, the inverted T shape of the male portion of the end piece makes it possible to retain the end piece radially including in the absence of tight mounting and/or weld points with the base.
(27) A second aspect of the invention will now be described, in relation with FIGS. 4a, 4b, 5, 6a, 6b and 6c. The second aspect of the invention relates to the problem of the measurement of the degree of wear of wipers in order to know if a replacement or a repair is necessary. At present, to measure the degree of wear of a part, it is known to measure said part before mounting it, then measuring it again during the maintenance operation: the difference between these two measurements is compared to a reference value in order to decide whether the wear is acceptable or not. This measurement may however be carried out in several ways, for example: a first way is to measure the height of the considered wiper with respect to the foot of the moving blade; a second way is to measure the height of the considered wiper with respect to the heel of the moving blade; a third way is to measure, once the moving blades are mounted on the wheel, the inner radius of the wheel at the level of the most upstream wiper and the outer radius at the level of the most downstream wiper, then to work out the average of these two measurements; a fourth way is to measure between two adjacent parts on a mounted wheel.
(28) If the measurements before mounting then during maintenance are not carried out in the same way, they are no longer comparable and the measurement of the degree of wear is flawed. If the measurement before mounting has not been carried out, it becomes impossible to measure the degree of wear. Finally, even if the measurements before mounting then after maintenance are indeed carried out and in the same way, this method requires measurement equipment and is quite long to implement because each part must be properly set before being measured and because the number of parts is important.
(29) The second aspect of the invention aims to propose a turbomachine blade provided with at least one sealing wiper of which the degree of wear is measurable in a more reliable and quicker manner than in the prior art.
(30) A first embodiment of a second aspect of the invention will now be described, in relation with FIGS. 4a, 4b and 5. According to the second aspect of the invention, the or each sealing wiper comprises a wear indicator; according to the first embodiment of the second aspect of the invention, the wear indicator is a geometric indicator, for example a notch. The first sealing wiper 3 according to the first embodiment of the second aspect 30 of the invention is schematically represented in perspective in FIG. 4a and according to a side view in FIG. 4b. In the case where the heel comprises a plurality of sealing wipers, FIG. 5 shows a schematic representation according to a top view of the first upstream sealing wiper 3 and of the second downstream sealing wiper 4 according to the first embodiment of the second aspect of the invention.
(31) FIGS. 4a and 4b show that the first sealing wiper 3 comprises a wear indicator in the form of a notch 36 formed in the radially outer surface 35 and in the first upstream side 33 of said first sealing wiper 3. This has the advantage of facilitating the visibility of the wear indicator during an inspection by endoscopy. If the first sealing wiper 3 is the single sealing wiper of the heel 2, the notch 36 may alternatively be formed in the radially outer surface 35 and in the second downstream side 34 of said first sealing wiper 3. The notch 36 has a height Ha1 which is measured along the first axis {right arrow over (z)}, a length Lo which is measured along the second axis {right arrow over (x)} and a width La which is measured along a third axis {right arrow over (y)} substantially perpendicular to the first and second axes {right arrow over (z)}, {right arrow over (x)}. The height Ha1 is preferentially comprised between 20% and 50% of the height of the sealing wiper 3, measured along the first axis {right arrow over (z)}. The length Lo is preferentially comprised between 10% and 25% of the length of the sealing wiper 3, measured along the second axis {right arrow over (x)}, the width La is preferentially comprised between 10% and 33% of the width of the sealing wiper 3, measured along the third axis {right arrow over (y)}. The notch 36 has a bottom from which an element 38 projects radially. This makes it possible to facilitate the measurement of wear. The element 38 is of height Ha2, measured along the first axis {right arrow over (z)}, less than the height Ha1 of the notch 36. The height difference between the height Ha1 of the notch 36 and the height Ha2 of the element 38 is preferentially comprised between 0% and 25% of the height of the notch 36. The element 38 may be of width, measured along the third axis {right arrow over (y)}, equal to or less than the width of the notch 36. The element 38 is typically of length, measured along the second axis {right arrow over (x)}, less than the length Lo of the notch 36 but may alternatively be of same length as the notch 36 as a function of the shape the notch 36—for example if the notch 36 has a rectangular profile and not a rounded profile.
(32) FIG. 5 shows that the first upstream sealing wiper 3 is equipped with the notch 36 in its radially outer surface 35 and in its first upstream side 33; whereas the second downstream sealing wiper 4 is equipped with a notch 46 in its radially outer surface 45 and in its second downstream side 44. In the same way as the notch 36 of the first sealing wiper 3, the notch 46 of the second sealing wiper 4 has a bottom from which an element 48 projects. The dimensioning of the notch 46 and the element 48 of the second sealing wiper 4 is preferentially done relative to the dimensions of the second sealing wiper 4, in an analogous manner to the dimensioning of the notch 36 and the element 38 of the first sealing wiper 3.
(33) A second embodiment of the second aspect of the invention will now be described in relation with FIGS. 6a, 6b and 6c. According to the second embodiment of the second aspect of the invention, the wear indicator is not a geometric indicator but a colorimetric indicator, for example in the form of an element 5 which is embedded in the or each sealing wiper. The element 5 is of a colour different from the sealing wiper in which it is embedded. The element 5 is for example made of a ceramic material or glass fibre. As long as the sealing wiper is not worn, the element 5 is not apparent from the radially outer surface of said sealing wiper. When the sealing wiper wears radially, the element 5 becomes apparent from the radially outer surface of said sealing wiper. The element 5 is preferentially covered, along the first axis {right arrow over (z)}, by a thickness of material of the sealing wiper comprised between 10% and 25% of the height of the wiper. Furthermore, the element 5 is preferentially dimensioned in the following manner: height, measured along the first axis {right arrow over (z)}, comprised between 10% and 30% of the height of the wiper; length, along the second axis {right arrow over (x)}, comprised between 10% and 30% of the length of the wiper; width, along the third axis {right arrow over (y)}, comprised between 30% and 100% of the width of the wiper.
(34) FIG. 6a shows a schematic representation in perspective of the first sealing wiper 3 according to a first alternative of a second embodiment of the second aspect of the invention. FIG. 6b shows a schematic representation in perspective of the first sealing wiper 3 according to a second alternative of the second embodiment of the second aspect of the invention. FIG. 6c shows a schematic representation in perspective of the first sealing wiper 3 according to a third alternative of the second embodiment of the second aspect of the invention,
(35) FIG. 6a shows that the element 5 according to the first alternative is entirely embedded in the first sealing wiper 3, in such a way that as long as the first sealing wiper 3 is not worn, the element 5 is not apparent from the radially outer surface 35, and is not apparent either from the first upstream side 33, the second downstream side 34, the first end 31 and the second end 32.
(36) FIG. 6b shows that the element 5 according to the second alternative is partially embedded in the first sealing wiper 3, in such a way that the element 5 is apparent from the first upstream side 33 independently of the wear of the first sealing wiper 3. If the first sealing wiper 3 is the single sealing wiper of the heel 2, the element 5 is equally well apparent from the first upstream side 33 or from the second downstream side 34 or both from the first upstream side 33 and the second downstream side 34. If the heel 2 comprises the first upstream sealing wiper 3 and the second downstream sealing wiper 4, the element 5 of the first upstream sealing wiper 3 is preferentially apparent at least from the first upstream side 33 of the first sealing wiper 3, whereas the element 5 of the second downstream sealing wiper 4 is preferentially apparent at least from the second downstream side 44 of the second sealing wiper 4.
(37) FIG. 6c shows that the element 5 according to the third alternative is partially embedded in the first sealing wiper 3, in such a way that the element 5 is apparent from the first upstream side 33, the second downstream side 34, the first end 31 and the second end 32 independently of the wear of the first sealing wiper 3.
(38) Each sealing wiper 3, 4 represented in FIGS. 4a, 4b, 5, 6a, 6b and 6c described previously has a first portion on the side of its first end 31, 41 and a second portion on the side of its second end 32, 42, the first portion being wider and higher than the second portion, the height being measured along the first axis {right arrow over (z)} and the width being measured along the third axis {right arrow over (y)}. In this case, the wear indicator in the form of a notch 36, 46 or in the form of an element partially or completely embedded 5 is arranged at least partially in the first portion. Indeed, the first wider and higher portion of each sealing wiper is then the portion intended to attack the abradable material of the inner surface of the stator and which is going essentially to undergo wear. However, the sealing wipers do not necessarily have the form that has been described, with first and second portions and the first portion wider and higher than the second portion; they may for example also be straight, depending on the engine. Generally speaking, the wear indicator according to an aspect of the invention is compatible with all types of wipers.
(39) The first and second aspects of the invention described previously may be implemented independently of each other, or instead in combination with each other in order to propose a sealing wiper comprising a base attached to the heel, an end piece removably interlocked with the base, and a wear indicator arranged on the end piece.
