TURBOMACHINE HOUSING EQUIPPED WITH AN ENDOSCOPIC INSPECTION AND A NUT MASKING DEVICE

Abstract

TURBOMACHINE HOUSING EQUIPPED WITH AN ENDOSCOPIC INSTRUMENT AND A NUT COVERING DEVICE. One aspect of the invention relates to a turbomachine housing (1) comprising: a wall (10); an endoscopic port formed in the wall (10); an endoscopic component (14) fixed to an external surface of the wall (10), the endoscopic component (14) comprising a conduit communicating with the endoscopic port and having an internal thread for screwing in a plug (28); and screw-nut type fastening means (22, 26) securing the component (14) to the wall (10). A covering device is press-fitted onto each nut (26) of the fastening means (22, 26) and configured to cover at least a portion of the nut (26) loosening notches. Figure to be published with the abbreviation: Figure 1

Description

Title of the invention: TURBOMACHINE HOUSING EQUIPPED WITH AN ENDOSCOPIC INSPECTION AND A NUT MASKING DEVICE. TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a turbomachine housing comprising one or more endoscopic organs. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] A turbomachine housing may include endoscopic ports and be equipped with endoscopic components commonly referred to as "endoscopic bosses". Each component is fixed to the outer surface of the housing and has an internal channel that communicates with an endoscopic port in the housing for the passage of an endoscope.

[0003] The component is fixed to the housing by means of screw-nut type fastening. It includes two screw passage holes whose heads bear against an internal surface of the housing and which receive nuts intended to bear against the component to tighten it against the housing.

[0004] The conduit of the organ includes an internal thread for screwing on an endoscopy plug. This plug is intended to be removed by an operator prior to passing an endoscope through the conduit and performing a turbomachine check.

[0005] During these inspection procedures, it was observed that an operator may mistakenly loosen the nuts on the component's mounting brackets when only the endoscopy plug should be loosened. This error can lead to the loss of the screws (and their corresponding nuts) within the engine, necessitating engine removal.

[0006] It was initially proposed to solve this problem by making two tack welds on each nut after it had been tightened. However, this solution proved ineffective because an attempt by an operator to loosen the nut could break the tack welds or cause the screw to break (and thus also necessitate removing the engine).

[0007] Patent EP3004567B1 describes a turbomachine housing equipped with an endoscopy device and a cover that at least partially covers the device's mounting means. The cover is arranged to allow free access to the device's conduit when the endoscopy plug is not screwed into the conduit. Furthermore, the plug includes means for bearing against the cover to keep it pressed against the device.

[0008] The solution described in patent EP3004567B1 requires additional locking elements to immobilize the cover and prevent it from falling into the engine after the cap is removed. It also requires adapting the shape of the cap. Summary of the invention

[0009] There is a need to provide an even simpler, more efficient and economical solution to the problem of the accidental loosening of the retaining nuts of an endoscopic organ.

[0010] According to a first aspect of the invention, this need is met by providing a turbomachine housing comprising: • a wall; • an endoscopy port made in the wall; • an endoscopic organ fixed to an external surface of the wall, the organ endoscopic comprising a conduit which communicates with the endoscopic port and which has an internal thread for screwing on a cap; and • screw-nut type fixing means holding the endoscopic organ to the wall.

[0011] The turbomachine housing is notable in that a masking device is tightly mounted on each nut of the fastening means and configured to mask at least part of the nut loosening notches.

[0012] In addition to the characteristics mentioned in the preceding paragraph, the turbomachine housing according to the first aspect of the invention may have one or more additional characteristics from among the following, considered individually or in all technically possible combinations: • the masking device is configured to completely mask the nut's loosening notches; • the masking device includes an orifice in which at least part of the nut is housed, the orifice having an internal surface of shape complementary to an external surface of the nut; • the masking device has the shape of a ring; • The masking device is in the shape of a cap.

[0013] A second aspect of the invention relates to a turbine comprising a casing according to the first aspect of the invention, the turbine preferably being a low pressure turbine.

[0014] A third aspect of the invention relates to a turbomachine, such as a turbojet or an aircraft turboprop, comprising a casing according to the first aspect of the invention. BRIEF DESCRIPTION OF THE FIGURES

[0015] Other features and advantages of the invention will become clear from the description given below, by way of example and not limitation, with reference to the accompanying figures, among which: • [Fig.1] is a schematic perspective view of a turbomachine housing equipped with endoscopic organs and endoscopy plugs; • [Fig.2] is a schematic perspective view of the housing of [Fig.1] without the endoscopic organs and endoscopy plugs; • [Fig.3] is a schematic perspective and axial section view along the longitudinal axis of the housing of [Fig.1]; • [Fig.4] represents a masking device mounted on a nut used to hold an endoscopic organ; • Figure 5 shows, in top view and half-section view, the masking device of Figure 4; and • Fig. 6 shows, in top view and in half-section view, the nut of Fig. 4.

[0016] For clarity, identical or similar elements are identified by identical reference symbols throughout the figures. DETAILED DESCRIPTION

[0017] Figures 1 to 3 show an embodiment of a housing 1 of a turbomachine. The turbomachine can be a turboprop or an aircraft turbojet, such as a twin-spool turbojet (one low-pressure spool and one high-pressure spool).

[0018] The housing 1 comprises a wall 10 and endoscopy ports 12, i.e., ports for the passage of an endoscope for inspecting parts inside the housing during an inspection operation. This inspection operation can be carried out under the wing, i.e., when the turbomachine is attached to a wing of the aircraft. The endoscopy ports 12 are formed in the wall 10 of the housing 1, and more particularly in a relatively thin portion of the wall 10.

[0019] The casing 10 can in particular be the casing of a turbine, preferably a low-pressure turbine in a twin-spool turbojet.

[0020] The endoscopy ports 12 are preferably spaced apart from each other along a longitudinal axis of the casing (the casing generally has an annular shape).

[0021] The number of endoscopy ports 12 in the housing 1 depends on the number of areas within the housing 1 for which endoscopy is desired. For example, there may be between one and ten endoscopy ports 12 for one turbine or between one and two endoscopy ports 12 per turbine stage. An endoscopy port 12 may be shaped cylindrical with a circular base, oval, polygonal... On [Fig.2], only three endoscopy orifices 12 have been represented.

[0022] An endoscopic organ 14 is attached to and fixed on the outer surface of the wall 10 of the housing 1, at each orifice 12, to define a protruding boss on the outer surface of the wall 10. This endoscopic organ 14, commonly called an "endoscopic boss," comprises a conduit 16 (also called a chimney), which communicates with the corresponding endoscopic orifice 12 of the housing 1, and two fixation orifices 18. The conduit 16 is preferably located between the two fixation orifices 18 (also called lateral orifices). The fixation orifices 18 of the organ 14 are aligned with fixation orifices 20 of the housing 1, also provided in the wall 10. The fixation orifices 18 and 20 serve as passageways for means of fixing the organ 14 to the housing 10.

[0023] The fastening means are of the screw-nut type. They comprise, for each fastening hole 18 of the component 14, a screw 22 and a nut 26. The screw 22 is engaged in a fastening hole 20 of the housing 10 and in the corresponding fastening hole 18 of the component 14, and comprises a head 24 which bears against the inner surface of the wall 10 of the housing 1. Each screw 22 receives the corresponding nut 26 which is screwed in from the outside and which is intended to bear against the component 14.

[0024] The conduit 16 includes an internal thread for screwing in a plug 28 for sealing the conduit. The plug 28 ensures the sealing of the housing 1. This plug 28 is intended to be removed from the conduit 16 to insert the endoscope for inspecting parts inside the housing during an inspection operation.

[0025] Figures 4 and 5 show a masking device 30 mounted on each nut 26 that secures the endoscopic organ 14, to prevent an operator from accidentally unscrewing the nuts 26. Figure 4 shows the masking device in position on a nut 26, and Figure 5 shows the masking device 30 alone. The nut 26 is shown alone in Figure 6.

[0026] With reference to Figures 4 to 6, the masking device 30 is configured to mask at least part of the loosening notches 36 of the nut 26, in other words, at least part of the notched area of ​​the nut 26 used for loosening. Preferably, the masking device 30 masks the entire notched area, i.e., the loosening notches 36 in their entirety.

[0027] By concealing at least part of the notches 36 of the nut 26, the masking device 30 indicates to the operator (responsible for the control operation) that this nut 26 is prohibited and complicates, or even makes impossible, the loosening of the nut 26. The risk of loss of the fastening means in the turbomachine is therefore eliminated.

[0028] The masking device 30 is arranged around and in contact with the notched area of ​​the nut 26. Furthermore, the masking device 30 can bear on the base of the nut 26, that is to say the part of the nut 26 having the largest diameter.

[0029] With reference to [Fig.5], the masking device includes an orifice 32 in which at least part of the nut 26 is housed. This orifice 32 advantageously has an internal surface 34 of complementary shape to an external surface of the nut 26, and more particularly an internal surface 34 of complementary shape to the serrated area of ​​the nut 26.

[0030] The masking device 30 is mounted tightly on the nut 26, in order to prevent any disengagement of the masking device 30, whether during the operation of the motor or during an endoscopic control operation.

[0031] The internal orifice 32 of the masking device 30 and the notched area of ​​the nut 26 have the same nominal dimensions, but different tolerances to obtain this tight fit (or adjustment).

[0032] In an embodiment shown in Figures 4 and 5, the masking device 30 has the shape of a ring. Its internal orifice 32 is therefore open. The ring can cover all or part of the serrated area of ​​the nut 26. It can also cover an area of ​​the nut without serrations.

[0033] In an alternative embodiment not shown in the figures, the internal orifice 32 of the masking device 30 is blind, i.e., not through-hole. Thus, the masking device 30 "caps" the nut and forms a cap.

[0034] The masking device 30 described above is simple to manufacture and easy to install. It thus provides a simple and economical solution to the problem of accidental loosening of the nuts securing endoscopic instruments. This solution requires no modification to the shape of the endoscopic plug or the shape of the endoscopic instrument.

[0035] The turbomachine housing according to the invention is not limited to a particular number of endoscopic ports or endoscopic components. It could comprise a single endoscopic port and a single endoscopic component. Similarly, the number of mounting holes in each component, and therefore the number of nuts to be concealed (per component), is not limited to 2.

Claims

Demands

1. Turbomachine housing (1) comprising: - a wall (10); - an endoscopy port (12) provided in the wall (10); - an endoscopic organ (14) fixed on an external surface of the wall (10), the endoscopic organ (14) comprising a conduit (16) which communicates with the endoscopy port (12) and which has an internal thread for screwing a plug (28); and - screw-nut type fixing means (22, 26) maintaining the organ (14) to the wall (10); characterized in that a masking device (30) is press-fitted onto each nut (26) of the fixing means (22, 26) and configured to mask at least part of the loosening notches (36) of the nut (26).

2. Housing (1) according to claim 1, wherein the masking device (30) is configured to mask the loosening notches (36) of the nut (26) in their entirety.

3. Housing (1) according to any one of claims 1 and 2, wherein the masking device (30) comprises an orifice (32) in which at least part of the nut (26) is housed, the orifice (32) having an internal surface of shape complementary to an external surface of the nut (26).

4. Carter (1) according to any one of claims 1 to 3, wherein the masking device (30) has the shape of a ring.

5. Carter according to any one of claims 1 to 3, wherein the masking device (30) has the shape of a cap.

6. Turbine comprising a casing (1) according to any one of claims 1 to 5, the turbine preferably being a low pressure turbine.

7. Turbomachine, such as a turbojet or turboprop, comprising a casing (1) according to any one of claims 1 to 5.

Images