RU2384750C1 - Composite light-weight vane, primarily for aircraft engine fans - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to aircraft engines and can be used in designs of aircraft engine fan designs. Proposed composite fan consists of shank and vane comprising carcass that forms the vane inner spatial geometry, inner and outer layers of composite reinforcing material applied onto said carcass on its both convex and concave sides to make the vane outer spatial geometry. Said carcass is made up of two parts, i.e. shank part made from easy and rigid material, for example mineral composite. Note here that both aforesaid parts are glued together.

EFFECT: expanded operating performances, reduced weight, ease and lower costs of manufacture.

2 cl, 4 dwg

Description

Technical field

The invention relates to mechanics, in particular to the structural elements of pumps and compressors of continuous displacement, and can be used in the construction of blades made of polymer materials for aircraft engines, as well as for industrial ventilation systems of large industrial buildings, vehicles, etc., to increase their operational characteristics.

State of the art

The well-known "Method of manufacturing composite propeller blades" according to the patent for the invention of the Russian Federation No. 2058250, class. F02K dated 03/19/92., In which the design of a composite propeller blade is disclosed. The blade contains a spar with a butt and casing. In this case, the cavities inside the spar and between the spar and the casing are filled with foam inserts.

The design of the blade is complex, and the manufacturing process is time-consuming. In addition, the use of a homogeneous filler material and non-optimal reinforcement of the bearing layers of the blade impairs the mechanical properties of the blade, which does not allow the use of such a design for fan blades.

The design of the propeller blade is disclosed in the "Method for the manufacture of all-plastic composite blades" according to the patent for the invention of the Russian Federation No. 1827982, class. B29C 70/24 from 09/30/1997. According to this invention, the blade consists of a system of layers of a reinforced prepreg parallel to each other but oriented at different angles with different orientations of the reinforcing threads wrapped around the core and the locking part, and additional compensating layers.

The disadvantages of the design is the complexity of its manufacture due to the presence of void zones between the layers of the blade and the gap of the reinforced material in the butt part, which reduces the strength characteristics of the structure. In addition, the blade has a large mass.

According to US patent No. 5279892, class. BVB 7/00 of January 18, 1994, the design of the fan blade of a gas turbine aircraft engine consists of outer layers of a composite prepreg surrounding a three-dimensional woven core made of fiber layers intertwined with reinforcing fibers, while the prepreg of the outer layers contains hydrocarbon fibers coated with rubber compound forming a unidirectional sheet. The core forms the internal spatial geometry of the scapula. A group of reinforced outer layers forms the outer geometry of the scapula.

The main disadvantage of this design of the blade is the large mass of the core, which increases the total weight of the blade, the cost and complicates the technology of its manufacture.

SUMMARY OF THE INVENTION

The objective of the invention is to develop such a design of the fan blades, which would have a small mass and would be easy to manufacture.

In addition, the design of the blade should provide its high strength characteristics, have a low cost.

The problem is achieved in that in a composite blade mainly for aircraft engine fans, consisting of a butt and a blade containing a core that forms the internal spatial geometry of the blade, the outer and inner layers of the composite reinforced material superimposed on the core respectively from both its convex and concave sides, and forming the external geometry of the blade, the core is made of two parts - the butt part of a light and hard material, such as polystyrene, and the blade hour it is made of a strong rigid material, for example, a mineral composite, while the butt and lobed parts are connected by an adhesive joint.

Moreover, in the composite blade, the outer and inner layers are pairwise combined into single layers of solid fabric of composite reinforced material, enveloping the butt part of the core with their middle part.

This embodiment of the fan blade allows to reduce its weight, as well as reduce the cost of manufacturing due to simplification of the design. This increases the fatigue strength of the scapula.

The invention is illustrated by drawings, in which:

figure 1 shows a General view of the fan blades;

figure 2 shows a section bB of figure 1;

figure 3 shows a section aa figure 1 is a cross section of a fan blade;

figure 4 shows a scan of the layers of composite reinforced material forming the external geometry of the scapula.

The implementation of the invention

In accordance with the invention, a composite lightweight blade mainly for aircraft engine fans is performed as follows.

The blade 1 (figure 1) consists of the aerodynamic part - the blade 2, made integral with the butt 3. The thickness of the blade 2 decreases to the front edge 7, the free end 4 and the trailing edge 6 and increases to its center and to the base of the butt 5. The blade 1 made of a composite reinforced material material having a carbon fiber base embedded in a polymer binder. The blade contains a core 9 of lightweight material that forms the internal spatial geometry of the scapula, and the outer and inner layers that form the bearing power part of the scapula superimposed on the core from both its convex and concave sides, respectively, and form the outer geometry of the scapula. The core 9 is made in the shape of a scapula with the exception of the thickness of the external power reinforcing layers ΔX, the thickness of which over the entire surface of the scapula is determined by calculations and experimental studies. The core is made of two parts - the butt part 11 of light and hard material, such as polystyrene, and the blade part 10 of a durable hard material, such as mineral composite, while the butt and lobe parts are connected by an adhesive joint.

The outer and inner layers are pairwise combined into single layers 21, 22, 23, 24, 25, 26 (Figs. 3, 4) of solid fabric composite reinforced material, enveloping the middle part of the butt part of the core with their middle part. The layers are made of woven carbon material with an elastic modulus (E> 9000 kgf / mm ² ) and are connected by a binder.

The manufacture of the blades can be made of the following materials: reinforcing fabric filler T-25; (VM) -73 TU-6-11-380-70, binder ВС-2561С TU-585-25-278-89, material with a reduced specific gravity PU-10 according to the instructions of VIAM PI 1.2.219-82, VK- glue 50 TU-1-595-24-201-85.

The configuration of the layers (see Fig. 4) of the fan blades is obtained by the topographic method used to determine embossed surfaces by sequentially laying the layers of curved surfaces on the curved shape of a double curvature core with a certain pitch H equal to the thickness of the layer of unidirectional fibers or fabric. The development of curved surfaces of the layers to obtain patterns of details of the cut of the blade is carried out by the model-breadboard method of designing reamers taking into account the deformation ability of the material (the ability of the fabric to change the network angle between the warp and weft threads when donning a curved surface without folds and seams).

Layers of the material are stacked sequentially with different angles of reinforcement of the fabric fibers or unidirectional material in a percentage of 0 ° (α3) - 60-80%, 90 ° (α2) - 10-20%, ± 45 ° (α1) - 10-20% that allows you to optimize the distribution of loads and the bearing capacity of the blade as a whole. The layers are oriented relative to the line of maximum thicknesses 8, which runs from the middle of the base of the butt 5 to the free end 4 of the blade 2. The configuration of the line of maximum thicknesses 8 is determined by the results of measurements of the spatial-spatial model of the blade and shows the maximum thicknesses in the longitudinal and transverse directions. This line shows the points of influence of maximum loads on the blade configuration, therefore, the threads are oriented relative to this line. The orientation of the filaments 0 ° and 90 ° is advisable in the central layers 24-26 of the “back” and “trough” of the pen 2 blades and 0 ° -45 ° in the subsequent layers 21-23, taking into account the direction of influence of power loads, the curvature of the surface of the blade, the thickness of the power layer and deformation properties of fabrics with the maximum possible skew angle between the warp and weft threads, which allows you to achieve a curved shape of the layers of the scapula without additional forming elements (folds, seams and tucks) and increase the shear, strength characteristics of the scapula. On the oriented layers, the locations of the control notch marks 21 ', 22', 23 ', 24', 25 ', 26' are determined, along which the layers 21, 22, 23, 24, 25, 26 are laid along line 8. The preform is assembled by sequentially laying the layers of fabric (or unidirectional material) 21-26 in accordance with the notches on the plane, then insert the core 9 and close the preform by combining the layers of fabric "back" and "trough" relative to the bend line 13. The layers are laid so that each the subsequent layer relative to the core completely covers the contours of the previous one. For high-quality laying in the mold, the obtained fan blade preform is subjected to vacuum processing followed by impregnation by known methods.

The blade according to the invention has the following advantages:

- low weight due to the lightened core;

- simple design and due to this high technological effectiveness in production;

- increase in strength characteristics due to the combination of external and internal power layers.

Claims (2)

1. A composite lightweight blade mainly for aircraft engine fans, consisting of a butt and a blade, containing a core that forms the internal spatial geometry of the blade, the outer and inner layers of the composite reinforced material, superimposed on the core from both its convex and concave sides, and forming the external geometry of the blade, characterized in that the core is made of two parts - the butt part of the light and hard material, for example, foam, and the blade part and durable hard material, such as mineralokompozita, wherein the blade portion and the butt linked adhesive compound. 2. Composite lightweight blade mainly for aircraft engine fans according to claim 1, characterized in that the outer and inner layers are pairwise combined into single layers of solid fabric composite reinforced material enveloping the middle part of the butt part of the core.

Images