RU2576716C1 - Method of making impeller of centrifugal compressor from composite material - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to the turbine machine building, namely to production of impellers of centrifugal compressor. Method of fabrication of impeller from composite material including cutting blade material layers, pressing in mold and pressing the wheel. When cutting layers of material extends beyond the blade circuit on the side of the root section length, larger arc length of the bearing ring between adjacent blades, and on the side of peripheral section at length, larger arc length of the cover disk between adjacent blades. Aerodynamic profile blades are made in the mold, then blades are placed into mold separator and in cavities of the separator formed support wheel and cover disc. Then on the cover disc are covered with layers of circle with sectors and strip with teeth, after which the separator is placed in the mold and compacted.

EFFECT: invention allows to create high-load structure of the impeller at considerable reduction of weight and increased stiffness and strength of the cover disk.

2 cl, 13 dwg

Description

The invention relates to the field of turbine engineering, and in particular to a method of manufacturing the impellers of a centrifugal compressor, in particular gas turbine engines, and can be used in aviation, rocket technology, automotive engines and other industries.

A 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). In the impeller of a centrifugal compressor made of composite material containing working blades attached by their supporting elements respectively to supporting elements radially spaced relative to each other, the working blades are made longitudinal, integrally with the leg connecting the feather and the supporting elements of the blade, while the wheel is equipped with profile spacers, each of which follows the shape of the legs of the scapula, made between adjacent legs of the scapula and connected by them. It has supporting elements and at least one cavity of relief. In this case, the supporting element is a wheel, and each supporting element of the blades and spacers is made in the form of a groove, the width of which is not less than the width of the ring. The legs of the blades and spacers are made with a reinforcing element.

For the manufacture of the proposed impeller of a centrifugal compressor, a method is proposed that allows the production of light cavities in the wheel structure without violating the integrity of the material structure. This goal is achieved by the fact that in the method of manufacturing the impeller of a centrifugal compressor from composite material, which includes cutting layers of material of the blades with supporting elements and supporting elements in an assembly mold, followed by connecting the supporting elements and supporting elements of the blades on the contact surfaces and pressing the wheel. The blade with the leg is completely cut out with a spacer and layers of various sizes of material, laid out in the mold and a spacer element is installed in the spacer, removed after pressing, and after installation and centering of the blades with supporting elements of the spacer and supporting elements in the assembly mold, they are connected between each other on contacting surfaces, while the supporting element is made by winding long-drawn composite materials on a mandrel, followed by pressing the elements in a mold.

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

The closest in technical essence to the claimed impeller is a "Method of manufacturing an impeller of a centrifugal compressor from composite material" (patent RU No. 2432502, CL F04D 29/28, published on 10.27.2011), taken as a prototype. A method of manufacturing an impeller of a centrifugal compressor from a composite material, including cutting layers of material of the blades, pressing them in a mold, placing and aligning the blades in an assembly mold and pressing the wheel. When cutting layers, the material 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, and from the side of the peripheral section to a length greater than the length of the arc of the covering disk between adjacent blades, while the outer surfaces of the support ring and the cover disk perform equidistant aerodynamic surfaces of the gas path. The aerodynamic profile of the blades is formed in the mold, then the blades are placed in the mold separator and the support ring and the 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 , in the punch, the outer surfaces of the support ring, and in the separator, the internal aerodynamic surfaces of the gas path of the casing disk and the support ring are formed.

The proposed method for manufacturing the impeller of a centrifugal compressor from composite material allows you to create a highly loaded structure with a significant reduction in its mass and increased rigidity and strength. However, the impeller made in this way has a cover disk formed of a composite material laid sequentially on each other in a spiral, and during operation, different forces act on the impeller, and especially the cover disk, including centrifugal and from the action of high-speed air currents, which can violate the solidity of the composite material and create the prerequisites for its destruction.

The problem solved by this invention is the creation of a monolithic wheel of a centrifugal compressor made of composite material with increased strength characteristics of the cover disk.

The task is achieved in that additional layers of composite material are applied to the outer surface of the casing disk, the cutting of which is made of two types of blanks: one represents a circle with a central hole in the form of a polygon, from the vertices of which cuts are created in the diametrical direction, creating sectors connected by an annular surface ; the second represents a strip, on one side of which teeth are cut. When laying these blanks into the mold, a continuous surface of the covering disk is formed.

A method of manufacturing an impeller of a centrifugal compressor made of composite material includes cutting layers of material of the blades. When cutting layers of material, they extend 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 disk between adjacent blades. The material is impregnated with a binder along the contour of the blade and fits into the mold, in which the aerodynamic profile of the blade is formed, and a part of the support ring and the cover disk from 1 to 20 mm in length are formed on the root and peripheral sections of the pen. In addition, the layers of material are cut to strengthen the cover disk: a circle is cut out, a central hole is made in the form of a polygon, from the vertices of which the material is cut in the diametrical direction, as a result, sectors are connected by an outer ring; strips are cut, on one side of which the teeth are made. Next, the blades are placed in a separator, providing a nominal location of the blades in the mold. Then, the material that extends beyond the contour of the blades is impregnated with a binder, and a support ring and a cover disk are preliminarily formed in the separator cavities. Then, a circle with sectors is applied to the latter from the injection cavity, and a strip with teeth is laid on the suction side, while the latter lie between the sectors, forming a continuous layer of composite material. After these operations, the separator together with the composite material is placed in the mold and pressed, and the outer surfaces of the cover disk are formed in the matrix, the outer surfaces of the support ring are formed in the punch, and the internal aerodynamic surfaces of the gas path of the cover disk and the support ring are formed in the separator.

In FIG. 1 shows a General view of the impeller of a centrifugal compressor made of composite material. Figure 2 presents the cross section of the impeller of a centrifugal compressor. In FIG. 3 - cutting material for working blades. In FIG. 4 - a mold for the manufacture of blades. In FIG. 5 - the blade after pressing. In FIG. 6 - section of the blade after pressing. In FIG. 7 - separator. In FIG. 8 is a plan view of a separator. In FIG. 9 cutting a circle with sectors for the cover disk. In FIG. 10 - open strips with teeth. In FIG. 11 is a view of the cover disk after laying on it a circle with sectors and strips with teeth. In FIG. 12 - mold in assembled condition, top view. In FIG. 13 is a cross-section BB of the mold in the assembled state.

The impeller of a centrifugal compressor (Fig. 1) consists of rotor blades 1, a support ring 2 and a cover disk 3, which is reinforced on the side of the injection cavity in a circle with sectors 32 (Fig. 9), and on the suction side, with a strip with teeth 33 (Fig. 1). 10). In section AA (Fig. 2), a support ring 2 and a cover disk 3 are shown, which are formed from material 8, 9 (Fig. 2, Fig. 3, Fig. 6) that extends beyond the contour in the root 5 and peripheral sections 6 blades, respectively, and also shows the strengthening of the cover disk 3 in a circle with sectors 32 (Fig. 9) and a strip with teeth 33 (Fig. 10). In this case, the material 8, 9 (Fig. 3, Fig. 6), extending beyond the blade, has a length in the root section greater than the length of the arc of the support ring between adjacent blades, and in the peripheral section more than the length of the arc of the cover disk between adjacent blades. The outer surfaces of the support ring and the casing disk are equidistant to the aerodynamic surfaces 18, 20 of the gas path 7 (Fig. 1, Fig. 2), respectively. Thus, a monolithic impeller of a centrifugal compressor of a rigid and durable construction with a reinforced casing disc and a calibrated gas path is obtained, which is very important, especially in the aircraft engine industry.

A method of manufacturing an impeller of a centrifugal compressor consists in cutting various sizes of layers of material 10 (Fig. 3) of the blades, the layers being cut taking into account that part of the material 8, 9 will accordingly form a support ring 2 (Fig. 1, Fig. 2) and cover disk 3 (Fig. 1, Fig. 2). In FIG. 3 shows the cutting of one layer of the scapula. The number and size are calculated for each specific wheel and blade configuration. Each layer is impregnated with a binder in zone 10 and outside the blade contour by 1 ... 20 mm (Fig. 3). After that, the layers are laid out in the matrix 11 (Fig. 4) of the mold, the punch 12 is installed and pressing is carried out in accordance with the technological regime for the applied composite material. After extrusion, a blade 1 is obtained (Fig. 4, Fig. 5), on the root section 16 of which a notch 14 (Fig. 6) of the support ring 2 (Fig. 1) is formed, and on the peripheral section 15 (Fig. 5), a notch 13 is formed (Fig. 6) a cover disk; basting 13, 14 are obtained with a length of 1 ... 20 mm. Part of the material 8, 9 remains in the initial state, from which the support ring 2 and the cover disk 3 will be completely formed in the future (Fig. 1, Fig. 2). Next, the material 8, 9, (FIG. 6), which is used to form the support ring 2 (FIG. 1, FIG. 2) and the cover disk 3 (FIG. 1, FIG. 2), is impregnated with the binder, and the blades 1 are installed in the separator ( Fig. 7), the main dimensions of which correspond to the dimensions of the gas path 7 (Fig. 2). The surface 17 (Fig. 7) forms the surface of the gas path 18 (Fig. 1, Fig. 2), and the surface 19 (Fig. 7) forms the surface 20 (Fig. 1, Fig. 2) of the gas path of the wheel. Surfaces 21 and 22 (Fig. 7) form the surfaces of the wheels 23 and 24 (Fig. 1), respectively, and surfaces 25 and 26 (Fig. 7) form the surfaces 27 and 28 (Fig. 1), respectively. The blades 1 are installed in the grooves 29 (Fig. 8), while the notch 13 (Fig. 6) of the cover disk and the notch 14 of the support ring fix the blade in the radial direction. Then, the material 9 (Fig. 6) is placed in the cavity between the surfaces 17, 21, 22 (Fig. 2, Fig. 7), in which a cover disk is formed, and the material 8 (Fig. 6) is placed in the cavity between the surfaces 19, 25 , 26 (Fig. 2, Fig. 7), in which the support ring is formed. Next, blanks are applied to the casing disk (Fig. 9, Fig. 10): from the side of the injection cavity, a circle with sectors, and from the side of the suction cavity, a strip with teeth. In the center of the circle of composite material (Fig. 9), a hole is cut out in the form of a polygon 34, from the vertices of which are made in the diametrical direction of the slot 35, so that sectors 36 are united by a peripheral ring 37 with an outer diameter equal to the overall diameter of the cover disk. From the side of the suction cavity, a blank (Fig. 10) of composite material is laid in the form of a strip with teeth, between which there is a platform 39, equal to the side 40 of the polygon (Fig. 9). Thus, on the cover disk, a composite layer is obtained (Fig. 11). The number of layers is determined by strength, and each subsequent layer is shifted relative to the previous one by an angle equal to:

360 °: n: m, where n is the number of sectors, m is the number of layers, determined by strength calculation. After laying additional layers on the cover disk, the separator together with the preformed wheel is mounted on the punch 31 (Fig. 13) and in the matrix 30. Pressing is carried out according to the regime appropriate for the material and binder of which the impeller of the centrifugal compressor consists.

This invention solves the problem of creating a highly loaded wheel structure of a centrifugal compressor made of composite material with increased strength of the cover disk.

Claims (2)

1. A method of manufacturing an impeller of a centrifugal compressor made of composite material, including cutting layers for the blades, the material extends beyond the contour of the blades from the root section to a length greater than the length of the arc of the support ring between adjacent blades, and from the peripheral section to a length of a large arc of the cover disk between adjacent blades, the aerodynamic profile of the blade is formed in the mold, then the blades are placed in the mold separator and in the separator cavities the support ring and the cover disk are formed, after which the separator is placed in the mold and pressed, the outer surfaces of the cover disk are formed in the matrix, the outer surfaces of the support ring in the punch, and the internal aerodynamic surfaces of the gas path of the cover disk and the support are formed in the separator rings, characterized in that before laying the separator in the mold, a circle is applied to the cover disk from the discharge cavity, in the center of the latter there is a hole in the form of a polygon, from ershin which are made in the diametrical direction of the slit are formed as a result of the sector, the combined circumferential ring having an outer diameter equal to the overall diameter of the disk coating, and by the suction cavity is applied to the strip with teeth between which there are platforms equal to the side of the polygon. 2. The method according to p. 1, characterized in that each subsequent layer from the circle with sectors and strips with teeth is shifted relative to the previous one by an angle equal to 360 °: n: m, where n is the number of sectors of the circle, m is the number of layers defined strength calculation.

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