RU196830U1 - Axial fan impeller - Google Patents

Abstract

The utility model relates to the field of fan engineering, in particular to the impellers of axial fans (hereinafter referred to as the RC), and can be used to create new designs of fan installations for enterprises of the chemical, petrochemical and other industries. The technical result of the utility model is the creation of an RC that meets the current level fan engineering according to technical and economic indicators, the manufacturability of its manufacture. The specified technical result in the implementation of the utility model is achieved due to the fact that in the RK, containing a sleeve with blades fixed to it with bolts with a tightening bolt, made of composite material, its metal sleeve is assembled integrally with bolts with a tightening of standardized forming elements in the form of a hub, a disk with evenly distributed over it along one of its sides of the bases, the number of which is equal to the number of attached blades. The bases are made in the form of rectangular parallelepipeds, the end surfaces of which are connected to the hub, form a plane to which the mating surfaces of the flanges of the cylindrical butt of the blades are adjacent. The possibility of fastening and turning with subsequent fixation in a predetermined position of the blades relative to the bases is ensured by the fact that they are aligned with their longitudinal axis under the butt of the blades in the cross section is an arc of a circle with a radius equal to the radius of the cylindrical butt of the blades, and the fixing of the blades is performed using pads having recesses, representing which in shape in their cross section have an arc of a circle with a radius also equal to the radius of the cylindrical butt of the blades and bolted connection with a tightening. Structural and technological solutions incorporated in the design of the Republic of Kazakhstan contribute to the expansion of its model range to the required dimensions, which are determined by the specific tasks of a particular enterprise .

Description

The utility model relates to the field of fan engineering, in particular, to the impellers of axial fans and can be used to create new designs of fan installations for enterprises in the chemical, petrochemical and other industries.

From the prior art it is known the impeller of an axial fan (see the description of the invention to patent No. 2205298, CL F 04D 29/32, published 27. 05. 2003 Bull. No. 15) containing a hub made of a Central sleeve and articulated with it two parallel plates with protrusions according to the number of blades. The axis of symmetry of each protrusion is parallel offset with respect to the corresponding diametrical axes of the sleeve. Inside each protrusion there are two inserts with the possibility of forming a channel between them to accommodate the shank of the blade and having grooves located perpendicular to the plates for the passage of the studs. Each liner has a profiled surface area, providing its movement along the guides installed on the inner surfaces of the protrusions of the plates.

A disadvantage of the known device is the lack of information on the relationship of the geometric parameters of the parts of the impeller, which does not allow it to be created without additional research.

There is no uniformity in the interpretation of fundamental basic concepts and terms in the subject of activity, which is the reason for misunderstanding, misunderstanding - the terms “hub” and “sleeve” are technically incorrectly used in the patent.

The term - a word or phrase - a name that denotes a strictly defined concept of any special field of science, technology, art (1).

Terms with corresponding definitions used in this context throughout the description, including the utility model formula:

The term “hub” should be understood as the central, usually thickened part of the wheel with a hole for landing on an axle or shaft. The hub is connected to the wheel rim with spokes or a disk (2).

The term "sleeve" should be understood as a part of a machine or device in the form of a hollow cylinder (cone) into the hole of which mating parts are included. The bushings are continuous and split. (2)

The term "axial fan" should be understood as a fan in which the direction of the meridional velocity of the gas-air mixture at the entrance to the impeller and at the exit of the impeller is parallel to the axis of its rotation. (3)

The term "fan impeller" should be understood as the rotating part of the fan, in which mechanical energy is transmitted to the air through the dynamic action of its blades. (4)

The term "helicopter rotor hub" should be understood as the central rotor assembly connecting the blades to the gear shaft. (5)

The term "axial fan impeller sleeve" should be understood as the central impeller assembly connecting its blades to the drive shaft.

The term "diaphragm" should be understood as a detail of machines, devices, apparatuses, structures, representing a wall or plate (solid or with a hole). (2)

The term "shank" should be understood as the name of the ends of some parts of machines (for example, X. crankshaft), tools (for example, X. drill, tap) or work tools (for example, X. stamp) to secure them or attach other elements or mechanisms. (2)

The term “screw blade comel” should be understood to mean the part of the screw blade used to fasten the blade in the screw hub (6)

The term "comel of the blade of the impeller of the axial fan" should be understood as the part of the blade of the impeller, which serves to fasten the blade in the hub of the impeller of the axial fan.

The term “rectangular box” should be understood as a straight box, in which all six faces are rectangles. (7)

The term "mating surfaces" should be understood surfaces that are in contact with the surfaces of other parts, but not being covered or covering. (8)

The term "arc of a circle" should be understood as part of a circle. (9)

The term "central angle" should be understood as the angle in the circle formed by two radii. (10)

The term "composite material" should be understood as material obtained by impregnation with a polymeric binder (mainly polyester resins) of fiberglass of different weaving, various glass mat and roving.

In view of the foregoing, in patent No. 2205298, class. F04D 29/32 the term “hub” incorrectly designates an axial fan impeller bushing made of a central hub (and not a bushing) and two parallel plates with protrusions articulated with it, whose symmetry axes for redistributing the centrifugal load are parallel offset with respect to the corresponding diametric axes hubs.

The offset of the axis of symmetry of the protrusions from the axis of rotation of the impeller for redistributing the centrifugal load is borrowed in the above patent from the design of the rotor bushings of helicopters, for example Mi-4, Mi-8, made according to the classical scheme with articulated mounting of the blades with the rotor hub, which allows them to oscillate relative to horizontal and vertical hinges under the action of the variable aerodynamic and inertial forces applied to them during helicopter flight at translational speed. As a result of this, the values of alternating stresses in the rotor blades are significantly reduced.

The rotor hub of the aforementioned helicopters has spaced horizontal as well as vertical and axial joints. In this case, the spacing (distance from the axis of rotation) of horizontal and vertical joints is used to ensure a more uniform load distribution between the needle bearings of the horizontal joint and thereby significantly increase their durability (11).

The axial fan impeller bushing according to the scheme adopted in the fan industry corresponds in design to the rigid helicopter rotor bushing having only an axial joint, which serves to change the operation angle of its blades in the fan impeller.

In the impeller of the axial fan, the blade oscillates in the plane of rotation and swing not by turning in the hinges, but due to the deformation of the blade. These deformations of the blades for the impellers of axial fans in all operating modes of their operation, in contrast to the rotors of helicopters, are permissible due to the sufficient strength of the materials used for their manufacture and there is no need to displace the longitudinal axis of the impeller blades from the axis of rotation.

An important advantage of this design of the axial fan impeller sleeve is its simplicity, which facilitates and reduces the cost of manufacturing the impeller and its maintenance in operation.

During its rotation, a certain pressure differential always takes place in the impeller of the axial fan in front of and behind the blade ring. In this case, when the impeller sleeve is leaking, parasitic flows occur, significant additional pressure losses and the fan efficiency decreases.

A disadvantage of the known device is also that the design of the articulated plates due to the presence of protrusions in them in this impeller of the axial fan does not form the diaphragm of its sleeve and thereby does not ensure its tightness.

Leakage of the impeller sleeve of the known device due to the lack of a diaphragm causes a decrease in fan efficiency by about 14% and an even greater decrease in pressure. (12)

Thus, the technical result set forth in the patent is not achieved in this impeller of the axial fan.

The closest in technical essence and the achieved result to the claimed utility model is the impeller of an axial fan, disclosed in patent RU No. 2205299, class. F04D 2 9/32 published May 27, 2003 Bull. Number 15.

In connection with the foregoing, regarding the use of the terms “hub” and “sleeve”, the axial fan impeller according to the aforementioned patent comprises an impeller hub in the form of a disk with a central hub and blades fixed in the hub with their cylindrical shanks with flanges, one of the disk surfaces being made with lodges having a cylindrical surface. Above each lodgement, an insert is installed with a reciprocal cylindrical surface, forming a lodgement with a space for placing the blade shanks with the possibility of rotation. Each liner and the corresponding lodgement are connected by studs installed with the possibility of fixing the shanks in a given position. The disc and liners are attached to the hub by means of bolts having a common axis. The blades, disc and liners of the impeller bush are made of fiberglass.

A disadvantage of the known device adopted for the prototype is the complexity of the design and, as a consequence, its low manufacturability, caused by the design of the liner, disk with lodgements, which lead to an increased cycle and the complexity of their manufacture, the complexity of the work during its installation and operation.

Excessive use of fiberglass in the design of the impeller sleeve, because it is sensitive to the technological conditions of manufacture and its cost is 2-3 times higher than the cost of metal.

A disadvantage of the known device is the lack of information about the relationship of the geometric parameters of the parts of the impeller, which does not allow it to be created without additional research.

The task to which the claimed technical solution is directed is to expand the arsenal of technical means in this area, as well as to increase the technical and economic indicators of the axial fan impeller by reducing the amount of fiberglass used and the complexity of manufacturing the structure.

The technical result is to expand the arsenal of technical means in this area, to obtain an impeller of an axial fan of an optimal design that meets the current level of fan building in terms of manufacturability, and simplifies its maintenance as part of the fan.

The specified technical result in the implementation of the utility model is achieved due to the fact that the impeller of the axial fan containing the impeller bushing, mounted on it with bolted joints with their cylindrical knots with shoulders with the ability to rotate the blades made of composite material, characterized in that the metal sleeve is assembled in one piece with the help of bolted connections with a tightening of the forming elements in the form of a hub with a height Hc having a dimension ratio HB + (3-5) mm where Hv is the height of the drive output shaft, and with a diameter Dc having a dimensional ratio of Dc ≤ 2.5 Hs, a disk whose thickness is in the dimensional range t = 8-45 mm, and a diameter Dd has a dimensional ratio of Dd ≤ 0.25 Drc, where Drk is the diameter of the impeller, with bases evenly distributed over it on one of its sides and mated with it using a bolt connection with a draw, the number of which is equal to the number of attached blades from 3 to 12, made in the form of a rectangular parallelepiped with a length dimension ratio a = 0.75d-1.5d, width s b = 1,1d-1,5d and heights h = 0,5d-0,75d each, where d is the diameter of the cylindrical butt of the blade, while the end surfaces of the bases facing the hub form a plane to which the mating surfaces of the shoulders are adjacent cylindrical butt of the blades, the intersection points of the longitudinal axes of which are located on the axis of rotation of the impeller, and the possibility of rotation with subsequent fixation in a predetermined position of the blades relative to the bases is ensured by the fact that they are coaxial with their longitudinal axis under the butt of the blades in cross-sectional shape representing an arc of a circle with a radius r equal to d / 2 and a central angle α in the dimensional range 165-170 degrees, and the fixing of the blades is performed using overlays having recesses that are in shape in their transverse a cross-section is an arc of a circle with a radius r equal to d / 2 and a central angle β within the dimensional limits of 160-180 degrees and a bolted connection with a puff.

The essence of the utility model is illustrated by graphic materials, which depict the following:

in FIG. 1 shows a layout of an impeller that has at least three blades. An example is a four-blade impeller;

in FIG. 2 depicts the uniform forming elements of the impeller.

in FIG. 3 shows a section AA in FIG. 1;

in FIG. 4 shows a section bB in FIG. 2.

The list of items for the description of the utility model:

1. Axial fan impeller bushing

2. The blade

3. Hub

4. Disk

5. The basis

6. Bolts of fastening of a disk with a nave

7. Bolts of fastening of the basis

8. Comet blades

9. Pads

10. Bolts of fastening of blades

The list of designations for the description of the utility model:

1. Hc - hub height

2. Dc - diameter of the hub

3. Dd - disk diameter

4. Drk - impeller diameter

5. d - diameter of the butt of the blade

6. r - radius of the butt of the blade

7. a - base length

8. b - width of the base

9. h - base height

10. α is the central angle of the circular arc at the base

11. β is the central angle of the circular arc in the patch

The impeller of the axial fan contains a sleeve 1 with blades 2 fixed to it with bolt connections with a tightening, the intersection points of the longitudinal axes of which are located on the axis of rotation of the impeller (Fig. 1).

According to a utility model, the hub 3 (Fig. 2) is made with a height Hc having a dimension ratio HB + (3-5) mm, where HB is the height of the drive output shaft, and a diameter Dc having a dimension ratio Dc ≤ 2.5 Hc.

The indicated hub size Hc is determined by the geometric dimensions of the working end of the output shaft HB of the impeller drive onto which it is installed during the assembly of the fan.

The diameter of the disk Dd 4 (Fig. 2) of the sleeve, the thickness of which is in the dimensional range t = 8-45 mm, has a dimensional ratio Dd ≤ 0.25 Drk, where Drk is the diameter of the impeller.

The dimensional ratio Dd allows in each case of manufacturing the impeller sleeve to place on it the necessary number of bases 5 evenly distributed over it along one of its sides (Fig. 2), equal to the number of attached blades from 3 to 12 (in Fig. 2 as an example The sleeve of a 4-blade impeller is shown).

The disk 4 with the help of bolts 6 with a tightening is connected to the hub 3, and then the bases 5 are evenly mounted on it, which are also connected to it with the help of bolts 7 with a tightening (Fig. 2, Fig. 3).

The base 5 is made in the form of rectangular parallelepipeds with a dimensional ratio of length a = 0.75d-1.5d, width b = 1.1d-1.5d and height h = 0.5d-0.75d each, where d is the diameter cylindrical butt 8 blades 2 and the dimensions of which, in turn, depend on the technical parameters of the fan (Fig. 2).

The end surfaces of the bases facing the hub form a plane to which the mating surfaces of the flanges of the cylindrical butt 8 of the blades 2 (Fig. 2) are adjacent and which are mounted on the sleeve with the possibility of rotation with the help of plates 9 and bolts 10 with a tightening (Fig. 3, Fig. 4).

The ability to rotate the blades 2 with subsequent fixation in a predetermined position relative to the bases 5 is ensured by the fact that in them coaxially with their longitudinal axis under the butt of the blades, recesses are made in cross-sectional shape representing an arc of a circle with a radius r equal to d / 2 and a central angle a, located in the dimensional range of 165-170 degrees (Fig. 4), and the fixing of the blades is carried out using a bolted connection with a puff and pads 9 having recesses, which are circular in shape in their cross section tee having a radius r equal to d / 2, and the central angle in the size range 160-18 0 degrees (FIG. 4).

Due to such a design, the proposed impeller of the axial fan has a simple design, the laboriousness of its manufacture, installation and replacement of the blades during assembly and repair is reduced.

The indicated dimensional limits and the ratio of the dimensions of the impeller allow you to create their technological standard range with a diameter of up to 10.4 meters, mainly for air cooling units and cooling towers.

The impeller of the axial fan (Fig. 1) works as follows: it is installed in the fan on the working end of the drive output shaft (not shown in the drawing), and when it is started, it is rotated. When rotating its blades 2 (Fig. 1) create an air flow in the fan casing (not shown), moving axially along the venting parts of the fan to its destination.

To switch to a different working mode of the impeller, it is necessary to change the angle of installation of its blades, for example, from the summer mode to the winter mode;

The design of the mounting of the blades on the sleeve allows the stationary state of the impeller to smoothly adjust the angle of installation of its blades within the limits determined by the operating mode of the heat exchanger.

To change the installation angle of the blade, it is necessary to loosen the bolts 10 of its fastening on the sleeve (Fig. 2), turn the blade 2 to the required angle and fix it by tightening the bolts 10 with a tightening.

Since the number of pads 9 a, respectively, and the bolts for fastening the blades on them 10 is selected depending on the layout of the impeller in the normal design process, it is not mentioned in the utility model formula.

The results of design and production and technological work indicate that the creation of an axial fan impeller according to the proposed technical solution will make it easy to constructively and technologically due to the simplicity that ensures its widespread use in fan building, to increase the manufacturability of its manufacture, reduce operating costs and achieve modern level of fan building.

Thus, the use of this impeller of the axial fan will allow to achieve the task, and the claimed solution can be recommended for use in the design of the impellers of axial fans of both general industrial and special purposes, mainly for air cooling units and cooling towers.

LITERATURE

1. Ozhegov S.I., Shvedova N.Yu. Explanatory dictionary of the Russian language. M. 1992, p. 823.

2. A large encyclopedic polytechnical dictionary.

3. GOST 22270-2018. Heating, ventilation and air conditioning systems. Terms and Definitions. paragraph 2.10.21.

4. GOST 22270-2018. Heating, ventilation and air conditioning systems. Terms and Definitions. Section 2.7 8.

5. GOST 21892-76 Helicopter propellers and transmission. Terms and Definitions. p. 12.

6. GOST 21664-7 8 Propellers for aircraft engines. Terms and Definitions. p. 26.

7. Vygodsky M.Ya. Handbook of elementary mathematics. M. 1975, p. 306.

8. Romanicheva E.T., Sokolova T.Yu., Shandurina G.F. Engineering and computer graphics. M. DMK Press, 2001. p. 434.

9. Vygodsky M.Ya. Handbook of elementary mathematics. M. 1975, p. 282.

10. Vygodsky M.Ya. Handbook of elementary mathematics. M. 1975, p. 283.

11. Danilov V.A. Mi-8 helicopter. Device and maintenance. M. Transport. 1988, p. 125.

12. Brusilovsky I.V. Aerodynamics of axial fans. M. 1984, p. 140.

Claims (1)

An impeller of an axial fan, comprising an impeller bushing, bolted to it with a bolt and tightened by its cylindrical lugs with flanges with the ability to rotate the blades, made of composite material, characterized in that the metal bushing is assembled integrally using bolted bolts from unified forming elements in the form of a hub with a height Hc having a dimensional ratio Нв + (3-5) mm, where Нв is the height of the drive output shaft, and a diameter Dc having a dimensional s the ratio of Dc≤2.5Hc, a disk whose thickness is in the dimensional range t = 8-45 mm, and the diameter Dd has a dimensional ratio Dd≤0.25Drk, where Drk is the diameter of the impeller, with one equally distributed over it sides and bases connected with it by means of a bolt with a tightening, the number of which is equal to the number of attached blades from 3 to 12, made in the form of a rectangular parallelepiped with a dimensional ratio of length a = 0.75d-1.5d, width b = 1, 1d-1,5d and heights h = 0,5d-0,75d each, where d is the diameter of the cylindrical butt of the lopas and, while the end surfaces of the bases facing the hub form a plane to which are adjacent the mating surfaces of the shoulders of the cylindrical butt of the blades, the intersection points of the longitudinal axes of which are located on the axis of rotation of the impeller, and the possibility of rotation with subsequent fixing in a predetermined position of the blades relative to the bases is provided the fact that in them coaxially with their longitudinal axis under the butt of the blades, recesses are made in shape, in cross section representing an arc of a circle with som r, equal to d / 2, and a central angle α, which is in the dimensional range of 165-170 degrees, and the fixing of the blades is performed using pads having recesses, which are in shape in their cross section in a circular arc with a radius r equal to d / 2, and a central angle β within the dimensional range of 160-180 degrees and a bolted connection with a puff.

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