RU2611495C2 - Method of fan impeller making - Google Patents

Abstract

FIELD: turbomachine building.

SUBSTANCE: performing reinforcing filler cutting to produce workpieces with sizes, exceeding blades dimensions on their root cross-section side. Placing workpieces into mold and whole impeller filler impregnation with binder is performed during one process cycle until moment of binder polymerization. Impeller blade consist of, at least, two layers of filler. Formation of blades and central disc elements is performed simultaneously by workpieces laying on mold working surface. Performing mold elements connection. Performing central disc finishing forming by individual filler workpieces laying on cylindrical and end parts of mold in disc area. After complete filler impregnation with binder all wheels uniform polymerization is carried out without polymerization boundaries with formation of monolithic impeller. Enabling reduction and simplification of process cycle, production of impeller with increased modulus of elasticity and ultimate strength.

EFFECT: invention can be used in production of fan impellers.

5 cl, 8 dwg

Description

The invention relates to the field of manufacture of impellers from composite material for fans, as well as for compressors of gas turbine engines.

Known invention according to patent No. 2374072 "Method for the production of blades."

The blade production method includes interconnected technological operations: preparation of the matrices of the upper and lower shells with the application of separation, decorative or protective layers, laying out the upper and lower shells of fiberglass impregnated with a binder with the placement of embedded elements.

The connection of the upper and lower shells with exposure and disassembly of the matrices. The calculation of the upper shell is carried out with the simultaneous shaping of the hollow elements along the perimeter and along the longitudinal axis of the shell. Hollow elements around the perimeter perform with a curved cross-section. Hollow elements along the longitudinal axis are made with a rectangular cross section. The connection of the laid uncured upper and lower shells is carried out with vertical collapse of the hollow elements. The gaps between the hollow elements, the lower and upper shells along the trailing edge are made with polymer aggregate. The invention is aimed at increasing the strength of the connection shells.

Obviously, with respect to the manufacture of impellers of a fan or compressor, this invention is directed to the manufacture of only an impeller element. Analysis of the invention allows to draw the following conclusions.

Obtained in the future, the impeller containing the blades according to the above patent will have a strength limit at the joints of the blades in the Central sleeve (disk).

Regarding production technology: the process of manufacturing the impeller will be long (consisting of many stages) and complicated, in the long run a long and complicated procedure for checking the assembly of the wheel as a whole will be required.

The blades made, and with them the impeller, will have manufacturing errors (discrepancies in weight, centering and other parameters will appear).

The closest analogue of the proposed claimed invention is a method of obtaining an impeller of a compressor according to the patent of Russia No. 2502601.

The essence of this invention lies in the fact that the cutting of the blanks from a composite material (it would be more correct to say, filler, since the composite material is a combination of filler and binder - note of the applicant) for the blades is carried out beyond the boundaries of the blades from the side of their root section to the length exceeding the arc length of the support ring between adjacent vanes. In this case, the pressing of the blades is carried out separately with the preservation of a part of the workpiece from the filler outside the blade contour, after which a support ring is formed with front and rear flanges, the blades are located with the layers of material laying outside the blade contour, and after installing the mold elements, the impeller is formed.

The main disadvantage of the closest analogue is that the impeller is "conditionally monolithic". Namely, being assembled from individual elements (including blades), after the final impregnation with a binder and subsequent polymerization, it contains within itself the boundaries of the polymerization of the binder. This negatively affects the strength of the impeller with an increase in the probability of rupture of the wheel along the boundaries of the polymerization of the binder.

In addition, the separate manufacture of the blades increases the technological cycle (total time) of the manufacture of the impeller, which, accordingly, increases the labor costs and, as a result, the total cost of the wheel. It should also be borne in mind that the separate formation of the blades requires a separate preparation of the binder. Given the inevitable error in the binder preparation process from individual components, as well as the binder polymerization process, one can make a statement about the presence of individual fragments with individual properties inside the impeller.

There are other disadvantages associated with the human factor, for example, in setting the angle of rotation of the blade, as a result of which the impeller will work significantly worse and with a reduced resource.

The objective of the invention is the development of such a method of obtaining the impeller, which would eliminate the above disadvantages, and also allowed to produce the impeller with higher technical characteristics, including modulus of elasticity, tensile strength and aerodynamic properties, low cost, reduced time costs, and also provide stable weight of the product.

This problem is achieved by the fact that in the method of manufacturing the impeller, including cutting reinforcing filler, for example, on the basis of fabric made of fiberglass or carbon fiber, to obtain blanks with dimensions exceeding the dimensions of the blades from the side of their root section, laying the blank in the mold, impregnation with a binder composition, for example epoxy or polyester resin, and pressing, the following are additionally introduced: laying the workpiece in a mold and impregnating the filler of the entire impeller with a binder, including the blades and the central disk, they are performed during one technological cycle until the binder is polymerized, while the wheel blades consist of at least two layers of filler, the formation of the blades and the elements of the central disk are performed simultaneously by laying blanks on the working surface of the mold, connect elements of the mold, perform the final formation of the Central disk by laying individual blanks of the filler on the cylindrical and end parts of the mold in the region disk, and after complete impregnation of the filler binder operate uniform polymerization entire wheel polymerization without boundaries within the impeller to form a monolithic impeller.

Additionally, the following process steps can also be applied.

1. Simultaneously with laying the filler on the working surface of the mold, partially impregnating the elements of the blanks from the filler with a binder, in turn, with the formation of the blades and elements of the central disk.

2. The upper part of the mold is made collapsible from the ratio that the number of elements of the upper part of the mold is equal to the number of impeller blades.

3. The final formation of the shape of the blades is carried out by laying several layers of filler of various sizes with the formation of the profile of the blades.

4. After completion of the polymerization of the binder, it is advisable to perform thermal stabilization of the monolithic impeller, which consists in the fact that the monolithic impeller is kept in the heating chamber in the range from 100 to 140 minutes at a temperature in the range from 70 to 90 degrees Celsius or in the range from 50 to 70 minutes at temperatures ranging from 110 to 130 degrees Celsius.

The following graphic materials are presented in the application, which show the appearance of the impeller, mold elements, and phased operations for the manufacture of a monolithic fan impeller.

Figure 1 - monolithic impeller.

Figure 2 - the lower part of the mold.

Figure 3 - application of the first layer of filler (for example, fiberglass).

Figure 4 - the upper part of the mold Assembly.

Figure 5 - application of the second layer of filler.

Figure 6 is a complete mold.

Figure 7 - applying a layer of filler for forming the Central disk (Central hub) of the impeller.

Figure 8 - removal and disassembly of the upper part of the mold.

In the drawings, the positions indicate the following elements.

1 - blade;

2 - the central disk (sleeve);

3 - formation of the blade;

4 - formation of a part of the central disk;

5 - formation of the blade;

6 - formation of a part of the central disk;

7 - the formation of the Central disk (Central sleeve) by applying filler to the walls of the mold;

8 - elements of the upper part of the mold.

The manufacture of a monolithic fan impeller (figure 1) of the claimed solution is as follows.

After preparatory work related to the preparation of equipment, cutting of the filler (the manufacture of blanks from the filler with dimensions exceeding the dimensions of the blades on the side of the root section by an amount not less than the height of the central disk, as well as the blanks from the filler to form the central disk) and the binder, proceed to laying the first layer of filler on the lower part of the mold (figure 2).

Laying (application) of the preform (figure 3) can occur both with and without impregnation of the filler with the binder (i.e., impregnation occurs after the preforms are laid in the assembled mold).

Simultaneously with the laying of the first layer (or immediately after laying the first layer) of the filler, the second layer (figure 5) of the filler is laid on the upper part of the mold (figure 4) similarly to the laying of the first layer.

Then the molds are interconnected so that the first and second layers of the filler are docked (figure 6).

The shape of the blades can be made "volumetric", i.e. the necessary (depending on the specific given characteristics) profile can be performed. For this, laying of several layers of filler of various sizes is performed (cutting of the filler, respectively, is performed in advance) between the lower and upper layers previously laid on the working surfaces of the mold. In this case, the necessary recesses can be formed inside the mold, the size and depth of which depends on the given final profile of the blades.

In the assembled mold, the filler is laid (from blanks designed to form the central disk) to form the central disk by overlaying the blanks on the walls in the inner part of the mold (figure 7). The blanks are overlapped with the formation of a single part without border design.

The binder is impregnated (if necessary under pressure) and the mold is left to polymerize the binder.

If necessary, the impeller is thermally stabilized, in that the monolithic impeller is kept in the heating chamber in the range from 100 to 140 minutes at a temperature in the range from 70 to 90 degrees Celsius or in the range from 50 to 70 minutes at a temperature in the range from 110 up to 130 degrees Celsius.

After polymerization, the mold is removed and disassembled (Figure 8), after which the monolithic impeller (Figure 1) is removed, mechanically eliminating possible binder cast-offs and prepared for operation.

As a result, the technical effect of the implementation of the proposed solution is as follows.

Complete and uniform reinforcement of the impeller elements by the filler simultaneously with the uniform polymerization of the binder increases the elastic modulus and tensile strength (including tensile strength) of the impeller as a whole, as well as its individual elements.

The most pronounced effect of the increase in strength is manifested in comparison with similar devices at the points of attachment of the blades to the central disk (hub), since the claimed technology for manufacturing the impeller virtually eliminates the assembly operations of individual assembly units of the wheel (for example, connecting the blades to the hub).

The uniform distribution of the filler with the simultaneous polymerization of the binder at all points of the impeller allows you to get a single part with the same strength characteristics, providing a special bond strength of the blades and the hub. As a result, not only the durability and margin of safety increases, but also there is the possibility of designing (with subsequent manufacture) fundamentally new devices (using fans or compressors) with improved characteristics.

For example, the resulting impeller with increased strength properties and having a minimum variation in parameters in serial production, a minimum deviation of the geometric center from the center of mass allows the creation of fans of increased dimensions (at least 0.6 m in diameter) operating at higher speeds compared to analogs (at least revolutions per minute) for a long time without loss of mechanical properties.

The inventive method of forming the impeller eliminates the possibility of the influence of the human factor on the occurrence of errors in setting the angle of rotation of the blade. As a result, the error in the geometrical form of the manufactured products is reduced, the spread of the products according to their characteristics is reduced, for example, a stable (permanently fixed) weight of the product is ensured, and the exclusion of fasteners from metal reduces the weight of the finished product.

The use of double-sided molding provides a smooth surface of the impeller, which increases its aerodynamic properties.

Performing thermal stabilization of the whole product additionally increases the strength of the impeller, increases the temperature of permissible deformation (HDT) of both the blades and the entire impeller.

The inventive method of manufacturing the impeller involves the exclusion from the manufacturing procedure of operations such as installation, molding and gluing of the blades, which ultimately reduces the time spent on the manufacture of the product, reduces labor costs and, consequently, the final cost of the impeller.

The inventive technology (method) of manufacturing the impeller is tested in production. The resulting impellers withstood the test program with increased requirements, which allows us to confidently confirm the superiority of manufactured products (monolithic impellers for cooling fans) over existing analogues in terms of declared characteristics.

Accordingly, the applicant substantiates the superiority of technological solutions set forth in the application over existing analogues.

Claims (5)

1. A method of manufacturing a fan impeller, including cutting reinforcing filler to obtain blanks with dimensions exceeding the dimensions of the blades from the side of their root section, laying the blank in a mold, impregnating with a binder composition and pressing, characterized in that the blank is placed in the mold and binder impregnation of the filler of the entire impeller, including the blades and the central disk, is performed during one technological cycle until the binder is polymerized, while the impeller blades They are made up of at least two layers of filler, the formation of the blades and elements of the central disk is performed simultaneously by laying the blanks on the working surface of the mold, the elements of the mold are connected, the final formation of the central disk is performed by laying the individual blanks of the filler on the cylindrical and end parts of the press forms in the region of the disk and after the filler is completely saturated with the binder, they uniformly polymerize the entire wheel without polymerization boundaries inside the working Olesa to form a monolithic impeller. 2. A method of manufacturing a fan impeller according to claim 1, characterized in that at the same time as filling the filler on the working surface of the mold, partially impregnating the elements of the workpieces from the filler with a binder, in parallel with the formation of the blades and central disk elements. 3. A method of manufacturing a fan impeller according to claim 1, characterized in that the final formation of the shape of the blades is carried out by laying several layers of filler of various sizes with the formation of the profile of the blades. 4. A method of manufacturing a fan impeller according to claim 1, characterized in that the upper part of the mold is collapsible from the ratio that the number of elements of the upper part of the mold is equal to the number of impeller blades. 5. A method of manufacturing a fan impeller according to claim 1, characterized in that after completion of the polymerization of the binder, thermal stabilization of the monolithic impeller is carried out, namely, that the monolithic impeller is kept in the heating chamber in the range from 100 to 140 minutes at a temperature in the range from 70 to 90 ° C or in the range of 50 to 70 minutes at a temperature in the range of 110 to 130 ° C.

Images