RU2502601C1 - Method of making compressor impeller - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of turbo machines and may be used in production of compressor impeller from composite materials. Layers of composite is cut to make blanks for making front and rear flanges, part of support ring and blade. Blades are pressed from the side of support ring mark root section. Billet is placed into mould for moulding support ring part, front and rear flanges. Note here that part of said billet is placed into mould separator cavity. Blades are placed in separator cutouts. Layers of material are impregnated and laid to ensure performing of support ring. Resilient male die is fitted in the mould to form inner surfaces of front and rear flanges and support ring. Material layers for rear flanges are laid on male die. Pressure male die in mounted and coupled with separator. Pressure is applied to said resilient male die for compaction and forming of compressor impeller.

EFFECT: lower weight, higher strength.

8 dwg

Description

The invention relates to the field of turbine engineering, and more specifically to methods of manufacturing impellers from composite material for a compressor of a gas turbine engine, mainly aircraft.

Known impeller of a centrifugal compressor made of composite material and a method for its manufacture (patent RU No. 2239100, class F04D 29/26, publ. 30.10.2002). The technical result is achieved by the fact that the profiled working blades are made integral with the leg connecting the feather and the supporting elements of the blade, while the wheel is equipped with profiled spacers, each of which follows the shape of the blade legs, is made between adjacent legs of the blades and connected to them, has supporting elements and at least one cavity of relief, while the supporting element is a ring, and each supporting element of the blades and spacers is made in the form of a groove whose width is not less than the width of the ring. In the method of manufacturing the impeller of a centrifugal compressor, a blade with a leg is cut out from material layers of various sizes completely with a spacer, laid out in a mold and a spacer element is installed in the spacer, removed after pressing, and after installation and centering of the blades with supporting elements and spacers and supporting elements in the assembly mold they are interconnected by contacting surfaces, while the supporting element is made by winding long composite materials s on the mandrel, followed by pressing the element into the mold.

According to this invention, obtaining a monolithic wheel is achieved, however, there are significant drawbacks in the design and method of its production: relatively increased mass of the wheel, to install the supporting element, it is necessary to groove an annular groove, while the fibers of the composite material are cut, which reduces the strength of the wheel.

The design of the impeller of the compressor (RU No. 2382910, class F04D 29/26, publ. 02/27/2010) contains individual sectors of a layered composite material on a polymer basis, combined into an impeller by at least four load bearing rings made of composite material, and each sector includes one working blade, the tail part of which is made in the form of a shank leg with curvilinear geometry defined by shelves separated by grooves placed along the height of the legs, under the corresponding power rings placed in quiet grooves.

According to this invention, obtaining a monolithic wheel is achieved, however, a massive hub increases the relative mass of the wheel, a complex technology for the manufacture of the shank of the blades.

A method of manufacturing an impeller of a centrifugal compressor made of composite material (patent RU No. 2432502, F04D 29/28, publ. 10/27/2011), including cutting layers of material of the blades, pressing them in the mold, placement and alignment of the blades in the assembly press the shape and pressing of the wheel, and when cutting layers of material they go beyond the contour of the blades from the side of the root section of the blade to a length greater than the length of the arc of the support ring between adjacent blades, and from the side of the peripheral section to a length greater than the length of the arc of the covering ska between adjacent blades, while the outer surfaces of the support ring and the cover disk are equidistant to the aerodynamic surfaces of the gas path, the aerodynamic profile of the blades is formed into a mold, then the blades are placed in the mold separator and the support ring and cover disk are pre-formed in the separator cavities, after which the separator is placed in the mold and pressed, the outer surfaces of the cover disk are formed in the matrix, and the outer surfaces of the bearing about the ring, and in the separator form the internal aerodynamic surfaces of the gas cycle of the cover ring and the support ring (prototype).

This invention solves the problem of creating a highly loaded design of the impeller of a centrifugal compressor made of composite material with a significant reduction in its mass and increased rigidity and strength. High strength characteristics are ensured by the presence of a cover disk, which can be strengthened by additional winding. However, there is no cover disk in the impellers of the compressor and fan, and without the latter, large loads will appear at the blade attachment point in the support ring, and at high centrifugal forces in the support ring, delamination of the composite material will begin, since the binder does not work well in tension.

The problem solved by this invention is the creation of a composite material of the impeller of the compressor, including the rotor blades, support ring, front and rear flanges, lightweight design with increased strength characteristics.

This goal is achieved in that the support ring, front and rear flanges are formed simultaneously in a single mold, and the flanges are formed from a single cutting material.

A method of manufacturing a compressor impeller from composite material includes cutting layers of material of the blade and flanges, pressing the blades in the mold, placing and centering them in the assembly mold. When cutting layers of material, part of their surface extends beyond the contour of the blades from the side of the root section of the blade to a length greater than the length of the arc of the support ring between adjacent blades. When designing the aerodynamic profile of the scapula, a part of the support ring with a length of 1 to 20 mm is formed on the root section of the scapular feather. When cutting layers of material for flanges, the dimensions of the front and rear flanges and the width of the support ring are taken into account in order to obtain them from a single layer. They impregnate layers of material that are intended for flanges and a support ring, and place them in a mold, while part of the composite material is placed in the cavity of the mold separator, which forms the front flange, and part of the material is placed in the separator cavity, which forms the aerodynamic profile of the support ring . Then the blades are inserted into the separator, which provides the nominal location of the blades in the mold, and this in turn fulfills the requirements of the design documentation for the impeller. After that, the material that extends beyond the contour of the blades is impregnated with a binder and preformed in the separator cavity in addition to the support ring material there. Next, an elastic punch is installed in the mold, which forms the front flange with the lower part, a support ring on the peripheral surface, and layers of composite material are laid on the upper part of the elastic punch to obtain the back flange, a pressure punch is installed, under the action of which the back flange is formed, and served pressure on the elastic punch forming the hub and flanges. Pressing is carried out according to the regime necessary for a particular composite material, disassembling by known technological methods. Thus, a monolithic impeller of the compressor of a rigid and robust design with a minimum specific gravity is obtained.

Figure 1 shows a General view of the impeller of the compressor. Figure 2 presents the cutting material of the scapula. In figure 3. Depicted is the cutting of a layer of composite material for forming the front and rear flanges and the support ring. Figure 4 shows a diagram of the pressing of the blades. In Fig.5 - the blade after pressing. Figure 6 - mold after laying in it blades and composite material for the design of the flanges and the support ring. 7 is a section aa of the mold. On Fig - mold, ready for pressing.

The impeller of the compressor (Fig. 1) consists of rotor blades 1, a support ring 2, a front flange 3 and a rear flange 4. A support ring 2 is formed of composite material 5 extending beyond the contour of the blade 1 during cutting (Fig. 2) and material 6 , which is formed from the workpiece (figure 3) and which forms the aerodynamic profile of the support ring. From the same blanks, front 3 and rear 4 flanges are formed (Fig. 1 and Fig. 3).

This design takes into account that composite materials have the greatest tensile strength along the fibers, and the most loaded due to the action of centrifugal forces is the place of attachment of the blades to the support ring, so the fibers in part 5 under the action of these forces will delaminate; in order to eliminate this drawback, the support ring is reinforced by flanges, which are combined by part 6 of the support ring and are made of a single cut material. Thus, the front 3, rear 4 flanges and part of the support ring 6 form a power element of the impeller, in which the fibers work in tension, because flanges are a fastener through which the forces arising from the rotation of the wheel are transmitted. The channel-shaped section of the power element (flanges 3, 4 and part of the support ring 6) provides high specific strength of the entire impeller structure.

A method of manufacturing a compressor impeller consists in cutting various sizes of material layers (FIG. 2) of the blades 1, while the layers are cut taking into account that part of the material 5 is intended to form part 5 of the support ring 2 (FIG. 1). Also, the layers of material are cut (Fig. 3) for the design of the front 3, rear 4 flanges and part of the support ring 6 (Fig. 1). The number of layers and their sizes (figure 2 and figure 3) are calculated for each specific wheel, taking into account the configuration of the blades, hubs, flanges and the required strength. Next, each layer that forms the feather of the blade (figure 2) is impregnated with a binder in zone 1 and 7 (figure 2), the cutting zone 7 will form part of the support ring 8 (figure 4) 1 ... 20 mm long and fix the blade in the separator 11 (6, 7) in the radial direction. Then the layers are laid out in the matrix 9 (figure 4) of the mold, the punch 10 is installed and pressing is carried out in accordance with the technological regime for the composite material used. After extrusion, a blade 1 is obtained (Fig. 5), a notch 8 is formed on its root section for part 5 of the support ring 2 (Fig. 1), part of the material 5 remains in its original state, from which part 5 of the support ring 2 will subsequently be formed (Fig. .one). Next, they impregnate the cutting of the layers (Fig. 3) and lay them out in the mold, while the annular part 3 (Fig. 3) is placed in the separator 11 (Fig. 6) in the cavity 12, where the front flange 3 (Fig. 1 and 6), and part 6 of the cutting is laid in the cavity 13 of the separator 11 (FIG. 6 and FIG. 7), in which part 6 of the support ring 2 is formed with the necessary aerodynamic profile (FIG. 1), when laying, the slots 14 are combined (FIG. .3) with slots 15 of the separator 11 (Fig.7). Then, in the slot 15 of the separator 11, the blades 1 (Fig. 6 and Fig. 7) are inserted all the way to the basting 8 in the cutting part 6 and the material 5 is laid in the cavity 13 (Fig. 5, Fig. 6 and Fig. 7), pre-impregnated with a binder . Part 5 of support ring 2 (FIG. 1, FIG. 6, FIG. 7, FIG. 8) is formed from material 5 (FIG. 5, FIG. 6 and FIG. 7). Next, an elastic punch 16 (Fig. 6, Fig. 7, Fig. 8) is installed in the mold, for example, from rubber, polyurethane, inflatable, etc. Part of the cutting 4 is laid on it (Fig. 3 and Fig. 8), a pressure punch 17 (Fig. 8) is installed, which provides the shape and dimensions of the rear flange and fasten together with the separator, for example, bolts (not shown). The elastic punch 16 is supplied with pressure, for example, by the cone 18 (FIG. 6, FIG. 7, FIG. 8), under the action of which the elastic punch 16 creates pressure on the composite material forming the support ring, the front and rear flanges. Pressing is carried out according to the regime corresponding to the applied composite material for the impeller.

After disassembling the mold, a monolithic impeller is obtained (Fig. 1), containing working blades, a support ring, front and rear flanges.

This invention solves the problem of creating a highly loaded compressor impeller design of composite material with a significant reduction in specific gravity and increase stiffness and strength.

Claims (1)

A method of manufacturing a compressor impeller from composite material containing rotor blades, a support ring, front and rear flanges, including cutting layers of composite material to produce a workpiece designed to form the front and rear flanges and part of the support ring with an aerodynamic profile, cutting layers of composite material for blades, which is carried out with the provision of going beyond the contour of the blades from the side of their root section by a length exceeding the length of the supporting arc the rings between adjacent blades, parts of the material intended to form part of the support ring, pressing the blades to obtain the outline of the support ring from the root section of the supporting section, while maintaining part of the material extending beyond the blade contour, intended to form part of the support ring, in the initial state, laying in the press the shape of the workpiece designed to form the front and rear flanges and part of the support ring, with the location of the parts of the said workpiece in the cavity of the mold separator, designed designed for the design of the front flange and the aerodynamic profile of the support ring, the subsequent laying of the blades in the slot of the separator, ensuring the nominal location of the blades on the supporting ring, the impregnation and laying of layers of material extending beyond the contour of the blades, with the preliminary formation of the supporting ring, installation of the a punch designed to form the inner surfaces of the front and rear flanges and the support ring, on which lay the material layers for the rear flange and, setting the pressure of the punch of the mold, bonding it to the separator and the formation of a monolithic impeller compressor compression by applying pressure on the elastic punch.

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