Boss with ring
The anti-wear ring addresses the issue of wear and damage in annular bosses by providing a protective layer that can be easily replaced, thereby extending the boss's lifespan and reducing maintenance costs.
Patent Information
- Application Number
- FR2023005256
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-05-26
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2043-05-26
AI Technical Summary
Annular bosses in certain applications, such as aircraft turbomachines, suffer from wear and indentation due to vibrating accessories, leading to premature damage and increased maintenance costs.
An anti-wear ring with an annular body solidified to the boss, featuring a relief for easy removal and replacement, is used to protect the internal side of the boss from damage.
The anti-wear ring extends the lifespan of the boss by absorbing shocks and preventing wear, allowing for cost-effective maintenance and replacement of the ring rather than the entire component.
Smart Images
Figure 00000010_0000 
Figure 00000010_0001 
Figure 00000010_0002
Abstract
Description
Title of the invention: Boss with ring
[0001] The present invention relates to an assembly comprising an annular boss having an internal face and an opening and extending along a longitudinal axis.
[0002] A part is known which comprises an annular boss on one of its walls. This boss extends in a longitudinal direction and is intended to receive an accessory which passes through the hole (central space) of this boss. For example, the hole of the boss passes through the wall, in which case the accessory opens out on either side of the wall. For example, this accessory is a pipe which is provided with a washer. The washer comes to bear and slides along the internal face of the boss, and thus contributes to keeping the accessory centered in the hole of the boss. The part comprising the annular boss is for example an aircraft turbomachine casing.
[0003] In operation, in certain situations the part vibrates and the accessory moves transversely in the boss and over time damages the internal face of the boss. This damage is for example wear and / or indentation. This damage is undesirable, on the one hand because it prevents the accessory from being correctly held in relation to the part, on the other hand because the accessory, no longer being centered, can come into contact with unwanted areas of the part which can be critical for the part. It is then necessary to replace the part as a precaution, which can involve very significant costs. Description of the invention
[0004] The present invention aims to remedy these drawbacks.
[0005] The invention aims to propose an assembly comprising a boss capable of receiving an accessory and for which the lifespan of the boss is extended compared to an existing assembly.
[0006] This object is achieved by the fact that the assembly further comprises an anti-wear ring which comprises an annular body which is secured to the boss and which covers the internal face of the boss, the annular body extending between a distal end and a proximal end which is located at the opening, the ring comprising a relief which extends from the proximal end outside the boss, the ring being capable of being detached from the boss by an action on the relief.
[0007] Thanks to these provisions, the accessory which is housed in the hole of the boss may damage the internal face of the annular body of the ring. The ring therefore protects the boss against wear and impacts caused by the accessory, so that the part can still be used. When the ring is too damaged, the relief of the ring allows, by acting on it using a tool, to remove the ring from the boss. It is then possible to replace the damaged ring with a new ring. Thus, the lifespan of the boss and therefore of the part fitted with this boss is not affected. In addition, the solution according to the invention is less expensive (cost of the ring plus cost of labor for its attachment to the boss) than other solutions such as plasma resurfacing of material on the internal face of the boss or adding material by welding.
[0008] Advantageously, the anti-wear ring is secured to the boss by friction of the annular body on the internal face.
[0009] Thus, the connection of the ring with the boss is easier to achieve.
[0010] For example, the relief is an annular collar which extends radially outwards.
[0011] This makes it easier to grasp the ring to extract it from the boss.
[0012] For example, the collar is extended at its radially external edge by a lip which extends longitudinally opposite the annular body.
[0013] This makes it even easier to grasp the ring to remove it from the boss.
[0014] For example, the internal face of the annular body is smooth.
[0015] Advantageously, the annular body comprises an external wall and an internal wall and a damping device located between these walls.
[0016] Thus, the ring is able to better absorb the shocks of the accessory, which protects the boss more effectively.
[0017] For example, the damping device comprises a plurality of separate blades which are distributed circumferentially and uniformly around the main axis of the body, each of these blades being in contact with the external wall and the internal wall and being shaped in a spiral around this main axis.
[0018] The invention also relates to a turbomachine casing comprising the above assembly.
[0019] The invention also relates to a device consisting of a casing above and an accessory comprising a conduit and a washer which is mounted on this conduit and which is capable of sliding in sliding connection along the internal face of the annular body of the anti-wear ring.
[0020] The invention also relates to a method for repairing an annular boss of a part, the boss having an internal face surrounding a central space extending along a longitudinal axis X and an opening on this central space, the boss being such that it comprises the following steps: (b) An anti-wear ring is provided which has an annular body extending between a distal end and a proximal end and which has a relief extending from the proximal end, and the annular body is inserted into the central space; (c) After step (b) the annular body is secured to the boss in such a way that the annular body covers the internal face, the proximal end is located at level of the opening and that the relief extends outside the boss.
[0021] The invention will be better understood and its advantages will appear better on reading the detailed description which follows, of embodiments shown as non-limiting examples. The description refers to the appended drawings in which:
[0022] [Fig-1] [Fig. 1] is a perspective view of a ring of an assembly according to the invention.
[0023] [Fig.2] [Fig.2] is a sectional view of a boss and a ring mounted on it boss of an assembly according to the invention.
[0024] [Fig.3] [Fig.3] is a variant of a ring of an assembly according to the invention.
[0025] [Fig.4] [Fig.4] is a perspective view of a casing carrying bosses, each boss which can be part of an assembly according to the invention.
[0026] [Fig.5] [Fig.5] is an enlarged view of region A of [Fig.4]. Detailed description of the invention
[0027] The invention is described below in the case where the part comprising the boss 80 is a casing 70 of an aeronautical turbomachine. However, the invention applies to any part. Such a casing 70 is illustrated in [Fig.4]. This casing 70 comprises several bosses 80 which are distributed over its side wall, and of which only one is visible.
[0028] In [Fig. 4], region A is a portion of the side wall of the casing 70 which includes a boss 80. [Fig. 5] is an enlarged view of region A. The boss 80 is annular, that is to say it has the shape of a tube whose wall has an internal face 81 which surrounds a hole. Thus, this hole is the central space 84 of the boss 80. The external face 82 of the wall of the boss 80 extends the external face 72 of the wall of the casing 70. The boss 80 extends along a longitudinal axis X. For example, the hole of the boss 80 is a cylinder (that is to say it has a constant section), for example of circular section. The central space 84 has an opening 83 which opens onto the exterior on the side of the external face 72 of the side wall of the casing 70. The boss 80 is capable of receiving an accessory 90, which can be of any type.For example, the hole in the boss 80 is a through hole that passes through the wall of the casing 70 and opens onto the inner face 71 of the side wall of the casing 70. In this case, the accessory 90 can pass through the wall of the casing 70. Such an accessory is visible in [Fig. 4]. For example, this accessory 90 is a pipe that comprises a conduit 91 that passes through the side wall of the casing 70 and a washer 92 that is mounted on this conduit 91. [Fig. 5] illustrates the accessory 90 before its insertion into the hole in the boss 80. The accessory 90 is illustrated in dotted lines when it is inserted into the hole in the boss 80. The washer 92 is able to slide in sliding connection in the hole in the boss 80 and its diameter is just less than the internal diameter of the hole. Thus, the washer 92 guides the accessory 90 along the internal face 81 of the boss 80 and holds the accessory 90 in a position. correct compared to the 70 crankcase.
[0029] In operation, in certain situations the casing 70 vibrates and the accessory 90 moves transversely (i.e. in a plane perpendicular to the longitudinal axis X) in the central space 84 of the boss 80 and over time the edge of the washer 92 damages the internal face 81 of the wall of the boss 80.
[0030] According to the invention, to prevent this damage to the boss 80, an anti-wear ring 10 is secured to each of the bosses 80, the function of which is to prevent wear and damage to the boss 80. This ring 10 is illustrated in [Fig. 1]. For the sake of brevity, the word “anti-wear” is omitted after each mention of the ring 10.
[0031] The ring 10 comprises an annular body 20 which extends between a distal end 22 and a proximal end 23 along a main axis C. The proximal end 23 is located at the opening 83, for example just outside the central space 84. The internal face 21 of the wall of the body 20 therefore extends between these two ends. Similarly, the external face 24 of the wall of the body 20 extends between these two ends. For example, the body 20 is a cylindrical cone of circular section which widens from the proximal edge towards the distal edge. For example, as illustrated in [Fig.l], the body 20 is a cylindrical tube of constant circular section. The main axis C is then the axis of revolution of the body 20.
[0032] For example, the internal face 21 of the annular body 20 is smooth, that is to say that the roughness of the internal face is not visible to the naked eye.
[0033] The ring 10 is secured to the boss 80 in such a way that the annular body 20 covers the internal face 81 of the boss 80. For example, the external face 24 of the body 20 is in contact over its entire surface with the internal face 81. Thus, the boss 80 is not in contact with the accessory 90 and is protected by the ring 10. In operation, the accessory 90 slides inside the annular body 20, along the internal face 21 of the wall of the body 20. If necessary, the geometry of the accessory 90 is modified to adapt to the ring 10.
[0034] The ring 10 also comprises a relief 30 which extends from the proximal end 23 outside the boss 80. Thanks to the fact that the relief 30 extends outside the boss 80, that is to say outside the central space 84, the relief 30 does not hinder the translation of the accessory 90 in the hole of the boss 80.
[0035] The relief 30 allows the ring 10 to be separated from the boss 80 by acting on this relief 30, as explained in more detail below.
[0036] The relief 30 may have various geometries. For example, as illustrated in [Fig.l], the relief 30 is an annular collar which extends radially outwards. The main axis C is then the axis of revolution of the ring 10. The reference 30 is used below to designate the collar. For example, this annular collar 30 extends in a plane perpendicular to the main axis C.
[0037] Thus, the assembly according to the invention comprises an annular boss 80 and an anti-wear ring 10, as described above.
[0038] A method for securing a ring 10 with an annular boss 80 (assembly method) is described below.
[0039] In a step (b), the annular body 20 is inserted into the central space 84. In a step (c), the annular body 20 is secured to the boss 80 in such a way that the annular body 20 covers the internal face 81 of the boss 80.
[0040] In one embodiment, in step (c), this joining is carried out by hooping so that there is frictional contact between the external face 24 of the annular body 20 and the internal face 81. This embodiment has the advantage of not using additional mechanical parts to achieve this joining.
[0041] For example, to achieve this hooping, the ring 10 is dimensioned such that the external radius R20 of the annular body 20 is just greater than the radius R80 of the central space 84 of the boss 80. By "just greater" is meant that R20 = R80 + d, where d is a distance less than for example one millimeter (mm), or for example 0.5 mm, or for example 0.3 mm, or for example 0.1 mm. The ring 10 is cooled such that the diameter of the annular body 20 decreases until R20 is less than R80. This cooling is for example carried out by immersing the ring 10 in liquid nitrogen (- 196°C). The annular body 20 is then inserted into the central space 84, then the ring 10 is heated to room temperature so that the annular body 20 returns to its initial dimensions and presses against the internal face 81. This situation is shown in [Fig.2]. A deformation of the annular body 20 and of the internal surface 81 occurs.For example, the annular body 20 deforms into a flared cone from the relief 30 towards the distal end 22 as shown in [Fig. 2], and presses against the internal surface 81. After securing the ring 10 with the boss 80, the longitudinal axis X and the main axis C are coaxial. The length of the body 20 is less than or equal to the length of the hole in the boss 80.
[0042] When the internal face 81 has defects, for example wear, before step (b) a step (a) is carried out in which this internal face 81 is machined until it is cylindrical with a constant cross-section. For example, this cylinder is circular. Thus, the internal face 81 is capable of matching the ring 10, the annular body 20 of which has an external face 24 which is circular cylindrical.
[0043] A method for separating a ring 10 from an annular boss 80 (disassembly method) is described below.
[0044] To achieve this separation of the ring 10 from the boss 80, in a step (d) an action is carried out on the relief 30 of the ring 10. For example, this action is a traction (and possibly a rotation) along the longitudinal axis X, this traction being directed towards the outside of the boss 80 so as to extract the ring 10 from the boss 80. This action is advantageously carried out by a tool.
[0045] In the case where the relief 30 is a collar, the tool is inserted under the collar 30 in order to exert the action of extracting the ring 10. Advantageously, the collar 30 is extended at its radially external edge 31 by a lip 40. The lip 40 is curved in such a way that it extends longitudinally (along the main axis C) opposite the annular body 20. The height of the lip 40 is less than the external height of the boss 80, that is to say the distance along the longitudinal axis X between the opening 83 of the boss 80 and the surface of the external wall 72 of the casing 70. The lip 40 contributes to holding the extraction tool in place on the collar 30 during the extraction action.
[0046] Thus, the invention relates more generally to a method for repairing a boss 80 which comprises steps (b), (c) and (d). Alternatively, this method further comprises step (a) before step (b) above. In the case where a ring 10 is already mounted on the boss 80 is already mounted on the boss, a prior step (d) is carried out before step (b), the ring 10 mounted in step (b) being distinct from the ring 10 removed in the prior step (d).
[0047] An alternative embodiment of the ring 10 according to the invention is described below, with reference to [Fig. 3].
[0048] The ring 10 has an annular body 20 and a relief 30. The difference with the ring 10 described above is that the annular body 20 has an external wall 26 and an internal wall 27 and a damping device 50 which is located in the space between these walls (26, 27).
[0049] For example, as illustrated in [Fig. 3], the damping device 50 comprises a plurality of disjointed blades 51 which are distributed circumferentially and uniformly around the main axis C of the body 20. Each of the blades 51 is in contact with the outer wall 26 and the inner wall 27 and is shaped in a spiral around the main axis C. Thus, each of the blades 51 is a portion of a tubular spiral which extends longitudinally along the main axis C over the entire length of the body 20. For example, the blades 51 are all identical and are superimposed by a fictitious rotation around the main axis C. The number of blades 51 is greater than two, for example greater than or equal to three, for example greater than or equal to four, for example greater than or equal to eight. For example, the number of blades 51 is equal to sixteen, as illustrated in [Fig. 3].
[0050] The damping device 50 makes it possible to absorb and dampen more effectively the movements and vibrations of the washer 92, and more generally of the accessory 90 in the body 20. Thus, the service life of the ring 10 is extended and it is necessary to replace it less often.
[0051] The ring 10 is manufactured by any means. For example, the ring 10 is manufactured by molding. For example, the ring 10 is manufactured by additive manufacturing. Thus, the manufacturing cost of the ring is reduced.
Claims
Claims
1. Assembly comprising an annular boss (80) having an internal face (81) and an opening (83) and extending along a longitudinal axis (X), said assembly being characterized in that it further comprises an anti-wear ring (10) which comprises an annular body (20) which is secured to said boss (80) and which covers said internal face (81), said annular body (20) extending between a distal end (22) and a proximal end (23) which is located at the level of said opening (83), said ring (10) comprising a relief (30) which extends from said proximal end (23) out of the boss (80), said ring (10) being capable of being detached from said boss (80) by an action on said relief (30).
2. Assembly according to claim 1 such that said anti-wear ring (10) is secured to said boss (80) by friction of said annular body (20) on said internal face (81).
3. An assembly according to claim 1 or 2 such that said relief (30) is an annular collar which extends radially outwards.
4. Assembly according to claim 3 such that said collar (30) extends at its radially external edge (31) by a lip (40) which extends longitudinally opposite said annular body (20).
5. Assembly according to any one of claims 1 to 4 such that the internal face (21) of said annular body (20) is smooth.
6. Assembly according to any one of claims 1 to 5 such that said annular body (20) comprises an external wall (26) and an internal wall (27) and a damping device (50) located between these walls (26, 27).
7. An assembly according to claim 6 such that said damping device (50) comprises a plurality of disjointed blades (51) which are distributed circumferentially and uniformly around the main axis (C) of said body (20), each of said blades (51) being in contact with said external wall (26) and said internal wall (27) and being shaped in a spiral around said main axis (C).
8. Turbomachine casing (70) comprising an assembly according to any one of the preceding claims.
9. Device consisting of a casing (70) according to the preceding claim and an accessory (90) comprising a conduit (91) and a washer (92) which is mounted on this conduit (91) and which is capable of sliding in connection slide along said internal face (21) of the annular body (20) of the anti-wear ring (10).
10. Method for repairing an annular boss (80) of a part, said boss (80) having an internal face (81) surrounding a central space (84) extending along a longitudinal axis (X) and an opening (83) on said central space (84), said boss (80) being characterized in that it comprises the following steps: (b) An anti-wear ring (10) is provided which comprises an annular body (20) extending between a distal end (22) and a proximal end (23) and which comprises a relief (30) which extends from said proximal end (23), and said annular body (20) is inserted into said central space (84); (c) After step (b), said annular body (20) is secured to said boss (80) in such a way that said annular body (20) covers said internal face (81), that said proximal end (23) is located at the level of said opening (83) and that said relief (30) extends outside of said boss (80).