Locks for securing aircraft engines, including paired encapsulated anti-friction coatings, and aircraft including such locks.

Abstract

The aircraft engine fastening latch (100) includes a ball joint with a shaft (170), the ball joint comprising: - a ring (110) including a first hole and a sleeve (120) fitted into the first hole and having a second hole, the second hole being configured to receive the shaft and having a gradually increasing diameter to have a flared inner surface at each end thereof, the fastening latch being arranged such that: - the spherical outer surface of the ring carries an anti-friction coating (111), the anti-friction coating being formed on a region extending beyond the contact area with the body of the latch, this first region being defined by an edge (112) forming a protrusion around the coating, and / or - the second hole carrying an anti-friction coating (121) on a region extending beyond its contact area with the shaft, this region being defined by an edge (122) forming a protrusion around the end of the flared inner surface of the anti-friction coating. Advantageously, this allows for an increase in the lifespan of the anti-friction coating by preventing peeling or flaking.

Description

Technical Field

[0001] This invention relates to a fastening latch for connecting an aircraft engine to an engine mount. More particularly, this invention relates to the arrangement of an anti-friction coating on the ball joint of such a latch, and to an aircraft including such a latch. Background Technology

[0002] Two-point or three-point fastening latches, sometimes called connectors or linkages, are commonly used to secure aircraft engines to engine mounts that are fixed to the aircraft's structure. These engine mounts participate in a so-called "isostatic" mechanical interface system, used to transfer forces, remain stationary in six degrees of freedom, and ensure stress-free installation while meeting certification and safety requirements. The mechanical interface system between the engine and the engine mount has specific characteristics that withstand high temperatures, taken into account its proximity to the engine, particularly regarding the so-called rear engine mount. Premature aging occurs, especially as these aircraft components undergo numerous thermomechanical cycles. Recent fastening techniques have enabled rapid installation and removal of aircraft engines using engine fastening latches, with the latches inserted and passing through U-shaped clips on the engine mounts or engines. These engine fastening latches use anti-friction coatings to limit wear on the contact surfaces between the connecting elements and improve the characteristics of the connection interface. Unfortunately, these coatings gradually degrade or peel off, primarily at or starting from their edges, resulting in stripping or delamination that compromises the quality of the achieved mechanical connection. This necessitates the replacement of the connecting parts bearing the coating.

[0003] Therefore, the situation can be improved. Summary of the Invention

[0004] The present invention is specifically designed to encapsulate the anti-friction surface coating of the connecting elements used for fastening aircraft engines with latches, and thus protect these coatings from premature wear.

[0005] Accordingly, the subject of this invention is a latch for securing an aircraft engine to a pylon attached to a structure of the aircraft via at least one axle. The latch includes a body and a point for fastening to the axle via a ball joint. The ball joint includes a ring having a spherical outer region and a first hole. The ring is fitted into a cavity in the body of the latch, the cavity having a shape complementary to the spherical outer region.

[0006] The latch further has the following features:

[0007] The ball joint includes a sleeve fitted into the first hole and having a second hole configured to receive the shaft and having a gradually increasing diameter to have a flared inner surface at each end.

[0008] - The spherical outer surface of the ring carries a first anti-friction coating, the first anti-friction coating being formed on a first region extending beyond the contact area between the ring and the body of the latch, and the first region being defined by a first edge that protrudes around the first coating relative to the spherical outer surface of the ring to form a protective stop around the first coating and encapsulate the first coating, and / or

[0009] - The second hole of the sleeve carries a second anti-friction coating in a second region extending beyond its contact area with the shaft, and the second region is defined by a second edge that forms a protrusion relative to the surface of the second hole at the end of the flared inner surface of the sleeve surrounding the second anti-friction coating.

[0010] Advantageously, the edges of the anti-friction coating applied to the surface of the mechanical connecting element can thus be protected by forming the boundaries of the protrusions and flanges, and the coating life can thus be increased by avoiding or reducing peeling or depolymerization. This can therefore reduce maintenance operations and related costs. Furthermore, it seems easier to recoat the surface in question in the event of coating wear.

[0011] The fastening latch according to the invention may also include the following features, individually or in combination:

[0012] - The first edge and the second edge have a height greater than or equal to 0.1 mm.

[0013] The surface of the cavity of the latch body, having a shape complementary to the spherical outer region of the ring, carries a third anti-friction coating. This advantageously improves the quality of the connection interface between the surface of the spherical region of the ring and the surface of the latch body that accommodates the ring.

[0014] - The first anti-friction coating is made of a copper-nickel-indium alloy of the Cu36Ni5In type or a cobalt alloy, and has a thickness between 50 μm and 300 μm, preferably 100 μm.

[0015] - The second anti-friction coating is made of a copper-nickel-indium alloy of the Cu36Ni5In type, a copper-aluminum-Fe alloy of the CuAlFe type, or a cobalt alloy, and has a thickness between 50 μm and 300 μm, preferably 100 μm.

[0016] - The third anti-friction coating is produced by integral processing or made of WC:CH type nanocomposite material, and has a thickness between 0.2 μm and 50 μm, preferably 5 μm.

[0017] - The body of the latch, the ring, and the sleeve are made of the same material, which is selected from titanium alloy or steel alloy.

[0018] Another subject of the invention is a fastening assembly comprising a latch as described above and a shaft bearing a fourth anti-friction coating on its outer surface, the fourth anti-friction coating being made of a nanocomposite material of the type WC:CH or WcCo and having a thickness between 0.2 μm and 50 μm, preferably 5 μm.

[0019] According to one embodiment, the shaft of the fastening assembly is made of a material selected from titanium alloy or steel alloy.

[0020] Another subject of the invention is an aircraft that includes the latches or fastening components described above. Attached Figure Description

[0021] The above and other features of the invention will become clearer from the following description of at least one exemplary embodiment, which is given with reference to the accompanying drawings, in which:

[0022] Figure 1 A component according to one embodiment is schematically and three-dimensionally shown for securing an aircraft engine to an engine pylon that is fixed to a structure of the aircraft.

[0023] Figure 2 The front view shows what has already been done. Figure 1 The fastening assembly is shown in three-dimensional form, and this planar front view defines a cutting plane A-A that is useful for the embodiments described below;

[0024] Figure 3 yes Figure 1 and Figure 2 The ball joint of the fastening assembly already shown in the diagram... Figure 2 The local section of section A-A;

[0025] Figure 4 It is shown schematically in an enlarged manner. Figure 3 Details of the implementation of the components shown;

[0026] Figure 5 The diagram schematically illustrates a ball joint used for securing a locking mechanism to an aircraft engine; and

[0027] Figure 6This is a top view showing an aircraft including a latch for securing the aircraft engine according to one embodiment. Detailed Implementation

[0028] Figure 1 The fastening assembly 10 is schematically shown, comprising: a fastening latch 100 having a generally flat body, a first ball joint having a shaft 170, and a second ball joint having a shaft 180. This type of fastening latch is commonly referred to as a two-point latch. It should be noted that the invention described herein can be applied to any connecting element including at least one ball joint, and is not limited to the case of a latch. The fastening assembly 10 is provided and configured to establish a fastening point between an aircraft engine and an aircraft engine pylon fixed to a structure of the aircraft. Thus, for example, shaft 170 is intended to be inserted through a through-hole in a fitting of the engine pylon or more precisely through a through-hole arranged in the side of a fastening U-shaped clip of the engine pylon, and shaft 180 is intended to be inserted through a through-hole in a fastening fitting of the aircraft engine or more precisely through a through-hole arranged in the side of a fastening U-shaped clip fixed to this engine. For example, the fastening assembly shown herein is used to establish a fastening point in the so-called "front" portion or the so-called "rear" portion of an aircraft engine. The front part of an aircraft engine is understood here as the part of the engine located on the side that the aircraft is facing during flight, while the rear part of the aircraft engine is understood as the part of the engine located on the opposite side that the aircraft is facing during flight, that is, on the side from which the aircraft originates.

[0029] The front part of an engine typically consists of a fan and a compressor stage of a turbine, while the rear part typically consists of a turbine stage of a turbine.

[0030] The ball joint between the body of the latch 100 and the fastening shaft 170 is formed by a ring 110, also known as an inner ring, which is generally spherical in shape and arranged in a through cavity having a surface shape complementary to the surface of the spherical region of the ring 110. The ring 110 includes a bore into which a sleeve 120 is inserted, the sleeve intended to receive the shaft 170. Similarly, the ball joint between the body of the latch 100 and the fastening shaft 180 is formed by a ring 130, also referred to as an inner ring, which is generally spherical in shape and arranged in a through cavity having a surface shape complementary to the surface of the spherical region of the ring 130. The ring 130 includes a bore into which a sleeve 140 is inserted, the sleeve intended to receive the shaft 180.

[0031] Rings 110 and 130 thus have spherical regions designed to contact surfaces of complementary shapes with the through-cavities, into which these rings are respectively inserted. Rings 110 and 130, thus arranged, rotate freely within their housings and are configured to achieve ball joints.

[0032] Advantageously, the anti-friction coating is used for the described ball joint, located between shaft 170 and sleeve 120, and between shaft 180 and sleeve 130.

[0033] Specifically, this anti-friction coating can create a lubrication and hardness-matching interface, which, for example, is inserted between two parts made of titanium or titanium alloys, thereby allowing relative movement between them.

[0034] This type of interface most often includes two coatings that form the adapter layer, wherein:

[0035] - A first adapter layer is deposited on the first part and has a hardness lower than that of the first part. This first layer includes a microporous morphology, which imparts lubrication adaptation function by fixing the grease of the liquid lubricant in the micropores.

[0036] - A second adapter layer that mates with the first layer and is deposited on the second part, the second layer having a harder hardness than the first layer, and further including a lubrication adapter function that releases solid lubricant under friction with the first part.

[0037] Typically, the fastening points at the rear of the engine are subjected to greater temperature stress due to the high temperatures generated by engine operation, and certain characteristics of such fastening components can vary depending on whether the fastening component is designed to achieve a connection at the front point (of the front part) or the rear point (of the rear part) of the aircraft engine.

[0038] Therefore, for example, the body of the latch 100, the rings 110 and 130, and the sleeves 120 and 140 are preferably made of titanium (Ta6V or, in another variant, a titanium alloy) when used to achieve a fastening point at the front of the engine; in the case of the so-called "cold latch" usage mode, when used to achieve a fastening point at the rear of the engine, the same elements are preferably made of Inconel 718 (or, in another variant, a steel alloy); and in the case of the so-called "hot latch" usage mode.

[0039] In the same manner as with regard to the materials used to manufacture the body, rings 110 and 130, and sleeves 120 and 140 of the latch 100, the characteristics of the anti-friction coating used may differ when there is a so-called "cold latch" usage mode in the front part of the engine or a "hot latch" usage mode in the rear part of the engine.

[0040] According to one embodiment, the following anti-friction coating is used for the "cold lock" arrangement on the front part of the engine:

[0041] - The coating applied to the body of the latch 100 onto a surface having a shape complementary to the spherical region of the ring is made of a nanocomposite material WC:CH.

[0042] - The coating applied to the spherical regions of each ring 110 and 130 is made of a copper-nickel-indium alloy of the Cu36Ni5In type.

[0043] - The coating applied to the surfaces of the holes in sleeves 120 and 140, including the flared portions applied to the holes, is made of a copper-nickel-indium alloy of the Cu36Ni5In type or a copper-aluminum-Fe alloy of the CuAlFe type.

[0044] - The coating applied to each shaft at 170 and 180 is made of a WC:CH type nanocomposite material.

[0045] Furthermore, the following anti-friction coating is used for the "thermal lock" located at the rear of the engine:

[0046] - The coating applied to the body of the latch 100 onto a surface having a shape complementary to the spherical region of the ring is produced by integrally treating the body of the latch 100, which is low-pressure carburizing.

[0047] - The coating applied to the spherical regions of each ring 110 and 130 is made of a cobalt alloy.

[0048] - The coating applied to the surfaces of the holes in sleeves 120 and 140, including the flared portions applied to the holes, is made of a cobalt alloy.

[0049] - The coating applied to each shaft at 170 and 180 is made of a WcCo-type nanocomposite material.

[0050] According to one embodiment, the thickness of the coating applied to the surfaces of the spherical regions of rings 110 and 130 and to the holes of the sleeve is between 50 μm and 300 μm, preferably 100 μm, and the thickness of the coating applied to the surfaces of the holes of the body of the latch 100 having a shape complementary to the shape of the surfaces of the spherical regions of rings 110 and 130 and to the outer surfaces of the shafts 170 and 180 is between 0.2 μm and 50 μm, preferably 5 μm.

[0051] Figure 2 This is a front view showing the fastening latch 100, and defining a section plane A-A relative to the latch body, also relative to the ring 110 and relative to the sleeve 120, which are configured to be aligned with the shaft 170 ( Figure 2 (Not shown in the image) together form a ball joint. The cutting plane A-A is used in conjunction with the plane described below. Figure 3 , Figure 4 and Figure 5 Related illustrative purposes.

[0052] Figure 3This is a partial cross-section of the fastening latch 100 along the cutting plane A-A, showing a ball joint located between the body of the latch 100 and the shaft 170, achieved by the arrangement of a ring 110 and a sleeve 120. The sleeve 120 is inserted into a hole in the ring 110, which has an overall external shape of a ball received within a spherical cavity of the body of the latch 100, the cavity having a shape generally complementary to that of the ring 110. The sleeve 120 includes a hole arranged around a longitudinal axis 123, configured to receive the shaft 170. Thus, a contact surface exists on one hand between the spherical region of the ring 110 and the body of the latch 100, and on the other hand, a contact surface exists between the inner surface of the sleeve 120 and the shaft 170. The arrangement of the ball joint achieved by the ring 130 and the sleeve 140 is not shown here, as it is similar to the arrangement of the ring 110 and the sleeve 120. For the purpose of better describing certain implementation details, Figure 3 The rectangular window 150 in Figure 4 Presented in a magnified format.

[0053] Figure 4 Shown in an enlarged manner Figure 3 A window is provided to more clearly display the implementation details.

[0054] Regarding the connection between the ring 110 and the body of the latch 100, the surface of the spherical region of the ring 110 carries a so-called "thick" coating 111 with a thickness on the order of 100 μm (between 50 μm and 300 μm), and is made of a copper-nickel-indium alloy of the Cu36Ni5In type when the latch 100 is used at the front fastening point of the engine, or a cobalt alloy when the latch is used at the rear fastening point of the engine. The surface of the body of the latch 100, having a shape complementary to the surface of the spherical region of the ring 110, carries a so-called "thin" coating 101 with a thickness on the order of 5 μm (between 0.2 μm and 50 μm), and the latch for the front fastening point in the so-called "cold latch" application is made of the nanocomposite material WC:CH, or the latch for the rear fastening point in the so-called "hot latch" application is produced by integral treatment (low-pressure carburizing) of the latch body. Cleverly, the edge 112 forms a protrusion and flange relative to the surface of the spherical region of the ring 110 to encapsulate the thick coating 111 applied to the surface of the spherical region of the ring 110, thereby preventing the edges of the coating 111 from peeling or flaking off and from gradually decomposing over even larger areas. Advantageously, the edge 112 forming the protrusion and flange on the surface of the spherical region of the ring 110 is circumferential, that is, it has an edge along the entire periphery of the free end edge of the ring 110. Advantageously, the protrusion of the edge 112 allows for the simultaneous formation of a bowl-shaped part with the bottom covered by the coating 111 and a lateral protective stop for the coating 111.

[0055] Regarding the connection between the sleeve 120 and the shaft 170, the inner surface of the sleeve 120, in other words, the surface of the bore of the sleeve 120, bears a so-called "thick" coating 121, with a thickness on the order of 100 μm (between 50 μm and 300 μm). When a latch is used at the front fastening point of the engine, it is made of a copper-nickel-indium alloy of the Cu36Ni5In type or a copper-aluminum-iron alloy of the CuAlFe type, or a cobalt alloy when a latch is used at the rear fastening point of the engine. Cleverly, the edge 122 forms protrusions and flanges to enclose the surface of the bore of the sleeve 120, including the thick coating 121 applied in region 120a, where the diameter of the bore gradually increases towards the end of the sleeve 120 and has an flared shape up to the edge 122. Again, this prevents the edges of the coating 121 from peeling or flaking off, or subsequently decomposing gradually over even larger areas. Advantageously, the edge 122 forming the protrusion and flange on the surface of the hole of sleeve 120 is circumferential, that is, it has an edge on the entire periphery of the free end edge of the hole. Advantageously, the protrusion of the edge 122 allows for the simultaneous formation of a bowl-shaped part with a bottom covered by coating 121 and a lateral protective stop for coating 121.

[0056] The shaft 170, which is engaged in the sleeve 120, carries a so-called “thin” coating 171. Figure 4 The arrangement of the components and the position of the coating only on one side of the ring 110, or in other words, only at one end of the sleeve 120, are shown. However, the described arrangement is identical on the other side of the ring 110, that is, at the other end of the sleeve 120, resulting in two edges 112 and two edges 122 respectively machined on the ring 110 and the hole in the sleeve 120. It should be noted, however, that the sleeve 120 is not entirely similar at its two ends, as it includes a shoulder 120' on the hole side of the ring 110 through which the sleeve is inserted into the ring. The flared shape of the hole in the sleeve 120 exists on both sides of the sleeve 120 to simplify the insertion of the shaft 170 by facilitating guidance and preventing any risk of damage to the coating during insertion along the longitudinal axis parallel to the hole in the sleeve 120. Of course, the dimensions of the components shown in the figures do not correspond to reference scale, and features are shown in an oversized manner to aid in the readability of the embodiment description. For example, the heights of edges 112 and 122 are deliberately exaggerated in the figure, as are the flared shapes at the ends of the inner surface of sleeve 120, or in other words, the flared shapes at the ends of the holes in sleeve 120.

[0057] Figure 5The entirety of the ball joint, i.e., ring 110, which forms the space between the body of latch 100 and shaft 170, is shown. Sleeve 120 is inserted into the ring and has a flared end hole around axis 123. The surfaces bearing the thick coatings 111 and 121 are defined by edges 112 and 122, respectively.

[0058] Figure 6 An aircraft 1 was shown, which includes at least a latch 100, or a similar latch for securing the engine, thereby advantageously increasing the lifespan of the engine mounting components.

[0059] This invention is not limited to the embodiments and examples described above, but more generally relates to any mechanical part, such as a latch for fastening, for example, an aircraft engine, the latch comprising an anti-friction coating applied to an area defined by an edge for the purpose of encapsulating the coating and limiting the risk of premature wear, peeling, separation, or depolymerization of the coating. In particular, variations may include anti-friction coatings other than those illustrated in the described examples. According to variations, the latch for fastening an engine according to the invention may also be configured to include more than two points for fastening to a shaft, for example, three points for fastening to a shaft.

[0060] According to a further variant, the surface of the spherical region of the ring of the described ball joint is supported by a friction-reducing coating defined by a protective edge, and the surface of the bore of the sleeve of the same ball joint is either not supported by a friction-reducing coating or is supported by a friction-reducing coating not defined by a protective edge.

[0061] According to a further variant, the surface of the bore of the sleeve of the described ball joint is supported by a friction-reducing coating defined by a protective edge, and the surface of the spherical region of the same ball joint ring is either not supported by a friction-reducing coating or is supported by a friction-reducing coating not defined by a protective edge.

Claims

1. A latch (100) for securing an engine of an aircraft (1) to a pylon attached to a structure of the aircraft (1) via at least one shaft (170), the latch (100) comprising a body and a point for fastening to the shaft (170) via a ball joint, the ball joint comprising a ring (110) having a spherical outer region and a first hole, the ring (110) being fitted into a cavity in the body of the latch (100), the cavity having a shape complementary to the spherical outer region. The latch (100) is characterized in that: The ball joint includes a sleeve (120) fitted into the first hole and having a second hole configured to receive the shaft (170) and having a gradually increasing diameter to have a flared inner surface at each end. - The spherical outer surface of the ring (110) carries a first anti-friction coating (111), the first anti-friction coating being formed on a first region extending beyond the contact area between the ring and the body of the latch (100), and the first region of the ring (110) being defined by a first edge (112) that protrudes around the first anti-friction coating (111) relative to the spherical outer surface of the ring (110) to form a stop for protecting and encapsulating the first anti-friction coating, and / or - The second hole of the sleeve (120) carries a second anti-friction coating (121) in a second region extending beyond its contact area with the shaft (170), and the second region is defined by a second edge (122) that protrudes relative to the surface of the second hole at the end of the second anti-friction coating (121) around the flared inner surface of the hole of the sleeve (120) to form a stop for protecting and encapsulating the second anti-friction coating.

2. The latch (100) for securing an aircraft engine according to claim 1, characterized in that, The first edge (112) and the second edge (122) have a height greater than or equal to 0.1 mm.

3. The latch (100) for securing an aircraft engine according to any one of claims 1 and 2, characterized in that, The surface of the cavity of the body of the latch, which has a shape complementary to the spherical outer region of the ring, carries a third anti-friction coating (101).

4. The latch (100) according to any one of claims 1 to 3, characterized in that, The first anti-friction coating (111) is made of a copper-nickel-indium alloy of the Cu36Ni5In type or a cobalt alloy, and has a thickness between 50 μm and 300 μm.

5. The latch (100) according to any one of claims 1 to 4, characterized in that, The second anti-friction coating (121) is made of a copper-nickel-indium alloy of the Cu36Ni5In type, a copper-aluminum-Fe alloy of the CuAlFe type, or a cobalt alloy, and has a thickness between 50 μm and 300 μm.

6. The latch (100) according to claim 3, characterized in that, The third anti-friction coating (101) is produced by integral processing or made of WC:CH type nanocomposite material and has a thickness between 0.2 μm and 50 μm.

7. The latch (100) according to any one of claims 1 to 6, characterized in that, The body, the ring, and the sleeve are made of the same material, which is selected from titanium alloy or steel alloy.

8. A fastening assembly (10) comprising a latch (100) according to any one of claims 1 to 7, and a shaft (170) having a fourth anti-friction coating (171) on its outer surface, the fourth anti-friction coating being made of a nanocomposite material of the type WC:CH or WcCo and having a thickness between 0.2 μm and 50 μm.

9. The fastening assembly (10) according to claim 8, characterized in that, The shaft (170) is made of a material selected from titanium alloy or steel alloy.

10. An aircraft (1) comprising a latch (100) according to any one of claims 1 to 7 or a fastening assembly (10) according to any one of claims 8 and 9.

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