FAN CASE FOR AN AIRCRAFT ENGINE

Abstract

The invention relates to a fan case for an aircraft engine in the region of the fan thereof, comprising a plurality of substantially cylindrically arranged fiber-reinforced plastic layers that are joined together, wherein a reinforcement ply made of glass fiber-reinforced plastic is disposed between an inner layer and an outer layer. According to the invention, the reinforcement ply consists of at least 20 plies of a glass fiber-reinforced plastic, and that deformation layers are disposed on both sides of the reinforcement ply, which deformation layers have a lower strength than the reinforcement ply.

Claims

1. A fan case for an aircraft engine in a region of a fan thereof, comprising a plurality of substantially cylindrically arranged fiber-reinforced plastic layers that are joined together, wherein a reinforcement ply made of a glass fiber-reinforced plastic is disposed between an inner layer and an outer layer, wherein the outer layer and the inner layer are made of a carbon fiber-reinforced plastic, the reinforcement ply consists of at least 20 plies of a glass fiber-reinforced plastic, that deformation layers are disposed on both sides of the reinforcement ply, which deformation layers have a lower strength than the reinforcement ply, and that a deflection ring made of a material having a higher strength than the deformation layers is disposed between the inner layer and the reinforcement ply in the region of the fan, wherein the deflection ring has a wedge-shaped cross-section with an inclined surface oriented towards the fan.

2. The fan case according to claim 1, wherein at least one deformation layer is formed by a honeycomb structure.

3. The fan case according to claim 1, wherein at least one deformation layer is formed by a foam material.

4. The fan case according to claim 1, wherein at least one fastening flange is integrated within the outer layer.

5. The fan case according to claim 1, wherein on the inner layer an abrasive layer made of a deformable material is disposed in the region of the fan.

6. The fan case according to claim 5, wherein the abrasive layer is made of a glass fiber-reinforced resin.

7. The fan case according to claim 1, wherein the deflection ring is made of metal.

8. (canceled)

9. The fan case according to claim 1, wherein the deflection ring is made of an aramid fiber-reinforced plastic.

10. (canceled)

11. (canceled)

12. The fan case according to claim 2, wherein at least one deformation layer is formed by a foam material.

13. The fan case according to claim 2, wherein on the inner layer an abrasive layer made of a deformable material is disposed in the region of the fan.

14. The fan case according to claim 4, wherein on the inner layer an abrasive layer made of a deformable material is disposed in the region of the fan.

15. The fan case according to claim 4, wherein the deflection ring is made of metal.

16. The fan case according to claim 5, wherein the deflection ring is made of metal.

17. The fan case according to claim 4, wherein the deflection ring is made of an aramid fiber-reinforced plastic.

18. The fan case according to claim 5, wherein the deflection ring is made of an aramid fiber-reinforced plastic.

19. The fan case according to claim 15, wherein the deflection ring is made of steel.

20. The fan case according to claim 16, wherein the deflection ring is made of steel.

21. The fan case according to claim 2, wherein the deflection ring is made of an aramid fiber-reinforced plastic.

22. The fan case according to claim 3, wherein the deflection ring is made of an aramid fiber-reinforced plastic.

23. The fan case according to claim 7, wherein the deflection ring is made of steel.

Description

[0020] The invention is explained in more detail by means of an exemplary embodiment below. Therein:

[0021] FIG. 1 shows an aircraft engine, partially in section, in an arrangement having a fan case disposed in the region of the fan; and

[0022] FIG. 2 shows a part of a fan case designed according to the invention, illustrated in section.

[0023] FIG. 1 illustrates an aircraft engine 2, partially in section, in an arrangement having a fan case 1 disposed in the region of the fan 3. Typically, a fan case 1 consists of a cylindrical jacket having fastening flanges and possible strengthening ribs or the like integrated therein and/or attached thereto. The fan case 1 is connected to the remaining engine housing, which is again arranged on corresponding fastening elements, usually wings.

[0024] FIG. 2 shows a part of a fan case 1 designed according to the invention, illustrated in section. The fan case 1 includes an inner layer 4 designed according to the aerodynamic requirements of the aircraft engine 2 and an outer layer 5 as well as a reinforcement ply 6 disposed between the inner layer 4 and the outer layer 5, and deformation layers 7 disposed on both sides of the reinforcement ply 6. Depending on the aircraft engine 2, the reinforcement ply 6 is formed by at least 20 plies of a glass fiber-reinforced plastic and is mainly used to withstand an impact of a part of the fan 3 in case of damage. The deformation layers 7, which may be formed by a honeycomb structure or suitable foam materials or combinations thereof, are used to absorb the kinetic energy originating from a disconnected part of the fan 3. The inner layer 4 may be made of a carbon fiber-reinforced plastic. The outer layer 5, which is mainly used to ensure residual strength of the fan case 1 in case of damage and to allow a safe landing with the damaged aircraft engine 2, is preferably made of a carbon fiber-reinforced plastic as well.

[0025] To simplify the work for production and mounting, the fastening flanges 8, 9 required for fastening the fan case 1 may be integrated within the outer layer 5 and be produced in one manufacturing process together with the outer layer 5. Due to the functional separation of the reinforcement ply 6 and the outer layer 5, tearing of the outer layer 5, in particular in the region of the fastening flanges 8, 9, can be prevented in case of damage, or at least the risk of damage can be reduced.

[0026] To reduce the air gap between the fan 3 and the inner layer 4, an abrasive layer 10 made of a deformable material may be disposed in the region of the fan 3, with the fan blade having the largest outer diameter cutting into the abrasive layer 10, resulting in a vanishingly small air gap between the fan 3 and the inner layer 4 and/or the abrasive layer 10. The abrasive layer 10 may be made of a glass fiber-reinforced resin or filled honeycomb cores.

[0027] In the region of the fan 3, a deflection ring 11 made of a material having a higher strength than the deformation layers 7 may be disposed between the inner layer 4 and the reinforcement ply 6, by which deflection ring 11 the radial forces occurring in case of damage are deflected to the sides. The deflection ring 11 may be made of metal, in particular steel, or also an aramid fiber-reinforced plastic, for example Kevlar®. For an ideal deflection of the radially acting forces, the deflection ring 11 may have a wedge-shaped cross-section with an inclined surface 12 oriented towards the fan 3, as illustrated.

[0028] At the rear end of the fan case 1, an extension element 13 may be disposed and preferably glued to the inner layer 4.