Method for producing a shielding cartridge for a turbomachine element and corresponding shielding cartridge and turbomachine element

Abstract

The invention relates to a method for producing a shielding cartridge (1) of a turbomachine element (10), said method comprising a step of winding a carbon wire (3) comprising a plurality of fibres about a longitudinal axis and a step of trapping and preserving the outside surroundings of the wound-up wire (3) in a housing (2).

Claims

1. A method for producing a shielding cartridge of a turbomachine element, the method including: winding a carbon wire about a longitudinal axis, the wound carbon wire including a plurality of fibers, and trapping and preserving the wound carbon wire in a housing, wherein the housing is closed by a cover, the housing and the cover comprising a metallic material or a metallic alloy, wherein the wound carbon wire is arranged in a plurality of rows in the housing, each row extending along a direction perpendicular to the longitudinal axis.

2. The method for producing according to claim 1, wherein closing the housing by the cover is carried out by welding in a vacuum or in a neutral non-oxidizing atmosphere.

3. A shielding cartridge of a turbomachine element, including a housing, a carbon wire wound about a longitudinal axis, wherein the wound carbon wire is trapped and preserved from outside surroundings in said housing, wherein the wound carbon wire includes a plurality of fibers, and a cover fixed to the housing, wherein the housing and the cover comprise a metallic material or a metallic alloy, wherein the wound carbon wire is arranged in a plurality of rows in the housing, each row extending along a direction perpendicular to the longitudinal axis, and wherein the wound carbon wire is not fixed to the housing.

4. The shielding cartridge according to claim 3, wherein the plurality of fibers include a polymeric material or a composite material.

5. The shielding cartridge according to claim 3, wherein the plurality of fibers are made of polyacrylonitrile.

6. The shielding cartridge according to claim 3, wherein a longitudinal section of the wound carbon wire is between 15,000 and 25,000 fibers per mm.sup.2.

7. The shielding cartridge according to claim 3, wherein the wound carbon wire includes two free ends in the housing.

8. A turbomachine element, including the shielding cartridge according to claim 3.

9. The shielding cartridge according to claim 3, wherein the wound carbon wire is a single wire.

10. A shielding cartridge of a turbomachine element, comprising: a housing, a carbon wire wound about a longitudinal axis, wherein the wound carbon wire is trapped and preserved from outside surroundings in said housing, wherein the wound carbon wire includes a plurality of fibers, and a cover fixed to the housing, wherein the housing and the cover comprise a metallic material or a metallic alloy, wherein the wound carbon wire is arranged in a plurality of rows in the housing, each row extending along a direction perpendicular to the longitudinal axis, wherein a longitudinal section of the wound carbon wire is between 15,000 and 25,000 fibers per mm.sup.2 to increase absorption of energy.

11. A shielding cartridge of a turbomachine element, comprising: a housing, a carbon wire wound about a longitudinal axis, wherein the wound carbon wire is trapped and preserved from outside surroundings in said housing, wherein the wound carbon wire includes a plurality of fibers, and a cover fixed to the housing, wherein the housing and the cover comprise a metallic material or a metallic alloy, wherein the wound carbon wire is free of resin around rows of said wound carbon wire, each row of said wound carbon wire extending along a direction perpendicular to the longitudinal axis, and and wherein the wound carbon wire is not fixed to the housing.

Description

5. BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood, and other purposes, details, characteristics and advantages of the invention will appear more clearly when reading the detailed explanatory description that follows, of the embodiments of the invention given as purely illustrative and not restrictive examples, with reference to the attached schematic drawings.

(2) On these drawings:

(3) FIG. 1 schematically illustrates an example of a shielding cartridge of a turbomachine element in axial section in accordance with the invention;

(4) FIG. 2 schematically illustrates a turbomachine element equipped with a shielding cartridge according to the invention;

(5) FIG. 3 shows a schematic representation of a wound-up wire;

(6) FIGS. 4a and 4b are perspective views of a cartridge and in axial section of the cartridge mounted on a turbomachine element following another embodiment; and,

(7) FIG. 5 shows a flowchart according to the methods of the invention.

6. DESCRIPTION OF EMBODIMENTS OF THE INVENTION

(8) A shielding cartridge 1 according to the invention is partially represented in axial section on FIG. 1. This shielding cartridge 1 is adapted to equip a turbomachine element such as a casing arranged facing a rotating blade member. Such a rotating blade member can be a compressor, turbine or fan rotor.

(9) The shielding cartridge 1 includes a housing 2 or an elongated gutter along a longitudinal axis X. FIG. 1 also shows an axis Y transverse perpendicular to the axis X and an axis Z, here vertical perpendicular to the axes X and Y. These axes X, Y, Z define an orthonormal mark. In the housing 2 is trapped and preserved from the outside surroundings a wound-up wire 3. The wound-up wire 3 is trapped in this example by means of a cover 4 attached to the housing 2. The cover 4 thus makes it possible to close the housing 2 in a sealed way and to preserve the carbon wire 3 from the outside surroundings. As illustrated, the housing 2 has a substantially U-shaped section with a base 6 extending along the longitudinal axis X and two side walls 7 extending from this base 3 along the vertical axis Z.

(10) The housing 2 is made of a metallic material or a metallic alloy. The metallic material can be titanium or steel, which can on one hand, provide good resistance to high temperatures and, on the other hand, resist to perforation and shearing. Titanium and steel are also lightweight materials. Alternatively, the material is a nickel-based metal alloy. An example of a metal alloy is Inconel 625, which also has good high temperature resistance properties. Advantageously, but not limited to, the housing 2 has a wall thickness of between 0.5 and 1.5 mm.

(11) The wire 3 wound-up in the housing 2 is made from a plurality of fibers allowing the shielding cartridge to resist deformations to absorb the energy of ejected fragments. The number of fibers composing this wire is included between 1,000 and 40,000. Each fiber has a diameter of between 4 and 8 μm. The wound-up wire 3 forms spirals of fibers with a high fiber density. The spirals of fibers are thus tightened to each other. The wire 3 is wound-up as a coil as shown schematically in FIG. 3 to optimize the number of spirals in a minimum volume. The wire 3 is wound-up along a longitudinal axis. The fibers are made of a polymeric or composite material. In this example the fibers include a polyacrylonitrile (PAN). The PAN fibers undergo several treatments to form the carbon wire. The PAN fibers have a high mechanical tensile strength of between 3,000 and 6,000 MPa. They also have a high elastic modulus of between 200 and 600 Gpa depending on the treatment used to obtain these fibers.

(12) Each spiral of the wire 3 includes, for a surface area of 1 mm.sup.2 between 15,000 and 25,000 fibers. In other words, the wound-up wire 3 includes in longitudinal section between 15,000 and 25,000 fibers per mm.sup.2.

(13) Thus, wound-up fibers can absorb about ten times more energy with a mass about four times lower than the shielding of the prior art.

(14) Alternatively, the fibers are made from any other equivalent carbonaceous member grouped together in the form of wire.

(15) The wire 3 includes two opposite ends that are free in the housing 2. In particular, the ends of the wire are arranged so that they are not fixed to housing 2 to avoid any delaminating effect of the fibers on potential interfaces. The mechanical assembly of the carbon wire 3 and housing 2 is carried out by the large number of spirals of the wire.

(16) In addition, no resin-based matrix is used to avoid any glass transition effect or the thermomechanical capacity of a matrix over time.

(17) The cover 4 makes it possible to seal the housing 2 when it is closed. The cover 4 is defined in a plane substantially parallel to the longitudinal axis X. The cover 4 is also made of a metallic material or a metallic alloy. Such a metallic material is steel or titanium to resist high temperatures. The latter are at least 500° C. A metallic alloy is a nickel-based titanium. The cover 4 is attached to the housing 2 to hold the wire wound-up in the housing 2. The fixing is carried out by means of a weld 5 performed preferably but not limited to, in a vacuum to isolate the fibers from the outside surroundings and in particular from oxidation. The cover 4 has a thickness of between 0.5 and 1.5 mm.

(18) FIG. 2 shows a partial illustration of a turbomachine element 10 in a cross-section. This element 10 is a turbomachine casing enclosing one or more compressor(s) and/or turbine(s) rotors. The compressor or turbine includes blades 11 on the periphery of a disc 13 driven in rotation along an axis O by a shaft of the turbomachine. The casing is equipped with a shielding cartridge 1 to ensure the retention of fragments of the blade and/or of the disc driven in rotation. The shielding cartridge 1 is fixed to the casing via fixing means 9 such as screws, bolts or other similar members. The fixing means 9 cooperate with the cover 4 for fixing the cartridge. In this example, the cover 4 includes lateral portions 14 of its wall extending on either side of the housing 2 with respect to the axis X. In other words, these cover portions overhang the side walls 7 of the housing 2. They extend along the axis X. These cover portions include openings 12 through which the fixing means 9 for fixing the cartridge 1 to the casing are inserted. These fixing means 9 only pass through these cover portions.

(19) Alternatively, as shown in FIGS. 4a and 4b, the shielding cartridge 1 is fixed to the casing via the fixing means 9 also cooperating with the cover 4. The latter includes lateral extensions 15 of its wall along the axis Y. These lateral extensions 15 extend only to one side of the cover 4 and the housing. These are evenly distributed on the periphery of one edge of the cover 4. The cover 4 in this example contains three lateral extensions 15. Each side extension 15 includes an opening 12′ to receive the fixing means 9. As in the previous example, the fixing means 9 include screws, bolts or other similar members. The lateral extensions 15 are fixed to the turbomachine casing via these fixing means 9. Once the lateral extensions are fixed, the housing 2 containing the wound-up wire 3 is arranged at a distance from the casing as the extensions protrude from a lateral wall of the housing.

(20) This shielding cartridge 1 is manufactured by a simple and inexpensive producing method. With reference to FIG. 5, the method includes a step E1 of winding of the carbon wire 3 including a plurality of fibers around a longitudinal axis and a step E2 of trapping and preserving the outside surroundings of the wire 3 wound-up in a housing 2. Before this step, one end of the wire is held temporarily attached in order to wind the wire more easily. The end of the wire can be temporarily attached, for example, with an adhesive.

(21) The step E2 of trapping and preserving includes a step E3 of closing the housing 3 with a cover 4 to ensure the tightness of the housing. Before closing the housing 2 with the cover 4, the end of the wire is held attached in the housing 2 is released. The closing step E3 is in this example performed by vacuum welding to avoid oxidation of the carbon wire 3.