RU2293885C1 - The body of an aviation engine's fan - Google Patents

Abstract

FIELD: the invention refers to the field of aviation mechanical engineering and may be used at designing, manufacturing and exploitation of turbo-fan engines.

SUBSTANCE: the body of the fan of an aviation engine has a casing out of composite material, zones of fastening with mated units and aggregates. It is fulfilled solid along the depth and multi-layer in the thickness of alternating spiral layers of organic braid and packets of organic cloth on epoxy binder. At that in the zone of the location of the blades spiral layers and cloth packets are repeatedly alternate with each other, and the inner and the exterior layers are fulfilled spiral, the end face zones are reinforced with cloth packets which are fastened with ring layers and elements of the pin-bolt connection are located in them.

EFFECT: the invention allows provision of fulfillment of demands of international norms at providing reliability and safety of the flight of a plane at the expense of containment of a turned off blade or its fragment by a fan's body.

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Description

The invention relates to the field of aircraft engineering and can be used in the design, manufacture and operation of turbofan engines.

Known technical solutions aimed at holding the collapsed blades and their fragments by the fan casing. US patent 5431532 dated July 11, 1995 proposes to use the material of the fan housing based on organ fiber, Kevlar, to hold off the torn fragments of the blades. The disadvantage of the proposed solution is a very complex rib design of the middle layer of the fan casing. Jamming of fragments of the blade between the ribs of the fan casing is not excluded, which can lead to destruction of the casing and the entire fan.

Closest to the claimed design of the fan casing made of composite materials (KM) are the solutions used on the D-36, D436K, D436T engines of the Zaporizhzhya Machine-Building Design Bureau (ZMKB) "Progress" described in the article by G. Peychev, S. Nikolaev ., Wiganta Yu.V. ZMKB Progress: composites in aircraft engines of the D-36 family (Technological Systems magazine 2/2000 - Anniversary collection dedicated to the 55th anniversary of the ZMKB Progress, pp. 15-21). The metal shell, which is a strength frame - a means for attaching a fan casing with adjacent nodes and a screen for the final retention of detached blades or their fragments is located above the KM insert. The disadvantages of fan cases of this design are the thermal and deformation incompatibility of metal composite materials. Thermal incompatibility is associated with a large difference in the linear expansion coefficients of metals and composite materials. The joint work of metal and composite shells in a wide temperature range (from minus 60 to plus 100 ° C) leads to high stresses at the metal-plastic interface and, as a result, to the possibility of delamination at this interface. The deformative incompatibility is due to a significant difference (by a factor of 2–3) in the elastic moduli of metal and composite materials.

The impact of the detached fragments of the blades on the combined shell of the body can significantly accelerate the process of its destruction.

The technical task of the invention is to increase the reliability of the design during operation of the fan.

The technical result is achieved in that the aircraft engine fan housing, comprising a sheath made of composite material, attachment zones with mating units and assemblies, is made integral in length and multilayer in thickness from alternating spiral layers of organ-bundle and organic tissue packets on an epoxy binder, while in the area of location the blades spiral layers and fabric bags are repeatedly alternated with each other, and the inner and outer layers are made spiral, end zones are reinforced with fabric bags, which They are fixed with annular layers and the elements of the pin-bolt connection are placed in them.

The inner and outer shells of the case are reinforced with spiral layers of Rusar, between them in the zone of the fan location an organic fabric is laid out, at the edges of the case the spiral layers are supplemented with fabric bags and are connected by an annular winding, forming a closed strength structure.

The implementation of the casing as one-piece in length and multi-layer in thickness from alternating spiral layers of organ-bundle and packages of organ-tissue allows you to create a solid structure that varies in physical and mechanical characteristics in the radial direction - the direction of alternation of layers. Repeated alternation of layers of spiral and fabric packets with each other allows you to organize numerous boundaries of different stiffness, crossing which the blade or its fragment lose energy. The implementation of spiral (single) inner and outer layers connected at the edges, allows you to get a closed rigid and durable construction of the housing. Strengthening the end zones with fabric bags allows you to develop thickenings in them to accommodate the pin-bolt connection.

The drawing shows a fan casing, where indicated:

1 - spiral layers of the rope "Rusar";

2 - fabric bags "Rusar";

3 - fasteners;

4 - panel noise reduction.

The work of the proposed design to hold the fan blade or its fragment, crashed tangentially into the fan housing, can be represented as follows.

1. When a small fragment of the fan blade breaks, it (the fragment) gives its energy to the elastic deformation of the fan casing, then flies out of it.

2. When a larger fragment of the fan blade breaks off, it (the fragment) partially gives up its energy to the elastic deformation of the case, partially damages the strong inner and hard layer, and then flies out of the fan case.

3. When the fan blade breaks, it breaks through numerous alternating layers reinforcing the fan casing, starting with the inner strong and hard layer of the zone spiral winding of the Rusar type organ-bundle and Rusar-type organ-tissue packages of longitudinally transverse laying and winding on the UP-2217 epoxy binder . The blade, tearing numerous layers of tourniquet and fabric, loses its energy and is held within the fan casing by covering with an inextricable layer of spiral winding of an organ-harness of the Rusar type.

Thus, the proposed design of the fan housing made of KM makes it possible to meet the requirements of international standards for ensuring the reliability and safety of flight of an aircraft by holding the torn-off blade or its fragment by the fan body. In addition, the proposed design allows to reduce the mass of the fan housing of the aircraft engine.

Claims (1)

Aircraft engine fan housing containing a shell made of composite material, attachment zones with mating units and assemblies, characterized in that the housing is made integral in length and multilayer in thickness from alternating spiral layers of organ-bundle and organic tissue packets on an epoxy binder, while in the area where the blades are located spiral layers and fabric bags are repeatedly alternated with each other, and the inner and outer layers are made spiral, end zones are reinforced with fabric bags that are fixed ring layers and in them the elements of the pin-bolt connection are placed.