CN118564305A - Shaft sleeve for adjustable blade, adjustable blade and aviation turbofan engine - Google Patents

Abstract

The present invention discloses a sleeve for adjustable blades, an adjustable blade and an aviation turbofan engine, which relates to the technical field of aviation turbofan engines, and comprises a sleeve body; a blind hole for mounting an upper shaft diameter or a lower shaft diameter of the adjustable blade is provided on the sleeve body, and the blind hole for mounting includes at least one opening, and the opening is arranged through the side wall of the sleeve body to form a mounting groove for inserting the upper shaft diameter or the lower shaft diameter of the adjustable blade. The sleeve for adjustable blades provided by the present invention can effectively increase the width of the upper shaft diameter or the lower shaft diameter of the adjustable blade by penetrating the blind hole for mounting on the sleeve body to the side wall of the sleeve body, thereby maximizing the width of the upper shaft diameter or the lower shaft diameter of the adjustable blade while ensuring that the size of the sleeve remains unchanged, thereby improving the mechanical properties such as the strength and stiffness of the adjustable blade shaft diameter.

Description

A shaft sleeve for adjustable blades, adjustable blades and aviation turbofan engine

Technical Field

The present invention relates to the technical field of aviation turbofan engines, and more specifically, to a shaft sleeve for adjustable blades, an adjustable blade and an aviation turbofan engine.

Background Art

Aviation turbofan engines are usually equipped with adjustable blades, and the upper shaft diameter of the adjustable blades is inserted into the outer ring component of the engine, and the lower shaft diameter is inserted into the inner ring component of the engine. The upper shaft diameter is driven by the engine's adjustment device so that the adjustable blades can rotate around the shaft diameter at a certain angle, thereby achieving pressure expansion and rectification, changing the airflow direction for the next stage rotor blades, and at the same time adjusting the airflow intake angle and angle of attack of the airflow to improve the flow field and inter-stage matching, ensuring stable engine operation and avoiding surge.

Conventional adjustable blades are generally connected to the inner and outer ring components of the engine by sleeves mounted on the lower and upper shaft diameters of the adjustable blades. The mechanical properties of the adjustable blade shaft diameter are mainly determined by the width and thickness of the upper and lower shaft diameters of the adjustable blades. However, due to the limitation of the aperture of the openings on the inner and outer ring components of the engine, the size of the sleeve is limited, so the expansion of the size of the mounting hole on the sleeve for mounting the lower or upper shaft diameter of the adjustable blade has limitations, resulting in poor effect on improving the mechanical properties of the adjustable blade shaft diameter and low safety of the adjustable blade.

Therefore, how to improve the mechanical properties of the adjustable blade shaft diameter while ensuring that the sleeve size remains unchanged has become a technical problem that needs to be solved urgently by those skilled in the art.

Summary of the invention

In view of this, an object of the present invention is to provide a sleeve for an adjustable blade, so as to improve the mechanical properties of the shaft diameter of the adjustable blade while ensuring that the size of the sleeve remains unchanged.

Another object of the present invention is to provide an adjustable blade having the above-mentioned shaft sleeve.

Another object of the present invention is to provide an aviation turbofan engine having the above-mentioned adjustable blades.

To achieve the above object, the present invention provides the following technical solutions:

A shaft sleeve for an adjustable blade, comprising:

A shaft sleeve body, wherein a mounting blind hole for mounting the upper shaft diameter or the lower shaft diameter of the adjustable blade is provided on the shaft sleeve body, wherein the mounting blind hole comprises at least one opening, and the opening is arranged to penetrate the side wall of the shaft sleeve body to form a mounting groove for inserting the upper shaft diameter or the lower shaft diameter of the adjustable blade.

Optionally, in the above-mentioned sleeve for adjustable blades, the mounting blind hole includes two coaxially arranged openings, and the two openings are respectively and coaxially arranged through the side wall of the sleeve body to form the mounting groove.

Optionally, in the above-mentioned sleeve for adjustable blades, the sleeve body is bonded to the upper shaft diameter or the lower shaft diameter of the adjustable blade by adhesive.

Optionally, in the above-mentioned sleeve for adjustable blades, a plurality of drainage holes are provided on the sleeve body, and the drainage holes are communicated with the mounting blind holes so that the adhesive flows out from the drainage holes.

Optionally, in the above-mentioned shaft sleeve for adjustable blades, a limiting ring is provided on the shaft sleeve body for facilitating the installation of the adjustable blades.

Optionally, in the above-mentioned sleeve for adjustable blades, the limiting ring is arranged on the sleeve body for being installed on the upper shaft diameter of the adjustable blade.

Optionally, in the above-mentioned sleeve for adjustable blades, the limiting ring and the sleeve body are an integrated structure.

Optionally, in the above-mentioned sleeve for adjustable blades, the material of the sleeve body is a metal material, a wear-resistant plastic material or a resin-based composite material.

An adjustable blade, comprising:

A shaft diameter, the shaft diameter comprising an upper shaft diameter for connecting to an outer ring component of an aviation turbofan engine and a lower shaft diameter for connecting to an inner ring component of an aviation turbofan engine, and the upper shaft diameter and the lower shaft diameter of the shaft diameter are respectively sleeved with a shaft sleeve for an adjustable blade as described in any one of the above items;

The guide plate includes at least one blade, and the blade is arranged on the shaft diameter along the length direction of the shaft diameter.

Optionally, in the above-mentioned adjustable blade, the guide vane includes two blades, and the two blades are arranged opposite to each other on the shaft diameter.

Optionally, in the above-mentioned adjustable blade, the blade and the shaft diameter are an integrated structure; and/or,

The material of the adjustable blade is a resin-based composite material.

An aviation turbofan engine comprises the adjustable blades as described in any one of the above items.

The shaft sleeve for adjustable blades provided by the present invention has a mounting blind hole opened on the shaft sleeve body, and an opening is provided on the mounting blind hole, and the opening is connected to the side wall of the shaft sleeve body to form a mounting groove into which the upper shaft diameter or the lower shaft diameter of the adjustable blade can be inserted, so that the width of the upper shaft diameter or the lower shaft diameter of the adjustable blade can be increased to the side wall position of the shaft sleeve body, and then the mechanical properties of the adjustable blade shaft diameter are effectively improved by increasing the width of the adjustable blade.

Compared with the prior art, the sleeve for adjustable blades provided by the present invention can effectively increase the width of the upper shaft diameter or the lower shaft diameter of the adjustable blade by setting an opening on the installation blind hole on the sleeve body, and the opening is set through the side wall of the sleeve body. By removing the redundant part of the sleeve for constraining the upper shaft diameter or the lower shaft diameter of the adjustable blade, the inner and outer ring components of the aviation turbofan engine are fully utilized to constrain the upper shaft diameter and the lower shaft diameter of the adjustable blade of the sleeve removal part, so that the width of the upper shaft diameter and the lower shaft diameter of the adjustable blade is maximized while ensuring that the size of the sleeve remains unchanged, thereby improving the mechanical properties such as the strength and stiffness of the adjustable blade shaft diameter.

The technical features mentioned above, the technical features to be mentioned below, and the technical features shown separately in the drawings can be combined with each other arbitrarily, as long as the combined technical features are not contradictory. All feasible feature combinations are technical contents clearly recorded in this article. Any of the multiple sub-features contained in the same sentence can be applied independently, and does not have to be applied together with other sub-features.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

FIG1 is a structural schematic diagram of a shaft sleeve provided in Embodiment 1 of the present invention;

FIG2 is a second structural schematic diagram of a shaft sleeve provided in Embodiment 1 of the present invention;

FIG3 is a first structural diagram of a shaft sleeve provided in Embodiment 2 of the present invention;

FIG4 is a second structural schematic diagram of a shaft sleeve provided in Embodiment 2 of the present invention;

FIG5 is a schematic diagram of the structure of an adjustable blade provided in Embodiment 1 of the present invention;

FIG6 is a schematic diagram of the assembly of the adjustable blade and the shaft sleeve provided in the first embodiment of the present invention;

FIG7 is a schematic diagram of the structure of an adjustable blade provided in Embodiment 2 of the present invention;

FIG8 is a schematic diagram of the assembly of the adjustable blade and the shaft sleeve provided in the second embodiment of the present invention;

FIG9 is a schematic diagram of the structure of an aviation turbofan engine provided by an embodiment of the present invention;

FIG. 10 is a comparison diagram of the bending and torsion performance of blades with adjustable edge shafts provided in an embodiment of the present invention.

Wherein, 100 is a shaft sleeve, 101 is a shaft sleeve body, 1011 is a mounting blind hole, 1012 is an opening, 1013 is a mounting groove, 1014 is a drainage hole, and 102 is a limiting ring;

200 is an adjustable blade, 201 is a shaft diameter, 2011 is an upper shaft diameter, 2012 is a lower shaft diameter, 202 is a guide vane, and 2021 is a blade;

300 is an aviation turbofan engine, 301 is a cap cover assembly, 302 is an air intake casing assembly, 3021 is an air intake casing support plate, 303 is a fan assembly, 3031 is a first-stage rotor blade, 3032 is a second-stage rotor blade, 3033 is a fan casing support plate, 304 is a core engine, and 305 is a tail cone.

DETAILED DESCRIPTION

The core of the present invention is to provide a shaft sleeve for an adjustable blade, so as to improve the mechanical properties of the shaft diameter of the adjustable blade while ensuring that the size of the shaft sleeve remains unchanged.

Another core of the present invention is to provide an adjustable blade having the above-mentioned shaft sleeve.

Another core of the present invention is to provide an aviation turbofan engine with the above-mentioned adjustable blades.

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

As shown in FIG9 , the aviation turbofan engine 300 mainly includes a cap assembly 301, an air intake casing assembly 302, a fan assembly 303, a core engine 304 and a tail cone 305. Specifically, the air intake casing assembly 302 includes an air intake casing support plate 3021 and an adjustable blade 200; the fan assembly 303 includes a first-stage rotor blade 3031, a second-stage rotor blade 3032 and a fan casing support plate 3033; the core engine 304 includes a compressor chamber, a combustion chamber and a turbine chamber assembly. It should be noted that FIG9 is only a schematic diagram of a typical structure of an aviation turbofan engine, and also includes other structural components, which are not specified in detail. In the present invention, it is only to point out the position of the adjustable blade 200 in the aviation turbofan engine 300.

As shown in Fig. 5 and Fig. 7, the adjustable blade 200 can realize pressure expansion and rectification by rotating around the shaft diameter 201 at a certain angle, change the airflow direction for the next stage rotor blade, and adjust the appropriate airflow inlet angle and angle of attack of the airflow, improve the flow field and interstage matching, ensure the stable operation of the engine, and avoid the purpose of surge. Specifically, the shaft diameter 201 of the adjustable blade 200 includes an upper shaft diameter 2011 and a lower shaft diameter 2012. During installation, the upper shaft diameter 2011 of the adjustable blade 200 is inserted into the outer ring component of the aviation turbofan engine 300, and the lower shaft diameter 2012 of the adjustable blade 200 is inserted into the inner ring component of the aviation turbofan engine 300, and the upper shaft diameter 2011 is driven by the adjustment device arranged on the outer ring component, so that the adjustable blade 200 can rotate around the shaft diameter 201 at a certain angle.

The conventional adjustable blade 200 is generally provided with sleeves on the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200, so that the adjustable blade 200 is connected to the inner and outer ring components of the aero-turbofan engine 300 through the sleeves, so as to ensure that the shaft diameter 201 of the adjustable blade 200 has stable mechanical properties. The mechanical properties of the shaft diameter 201 of the adjustable blade 200 are mainly determined by the width and thickness of the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200. However, due to the limitation of the aperture of the opening on the inner and outer ring components of the aero-turbofan engine 300, the size of the sleeve is limited, so that the size of the mounting hole on the sleeve for mounting the upper shaft diameter 2011 or the lower shaft diameter 2012 of the adjustable blade 200 has limitations, so that the effect of improving the mechanical properties of the shaft diameter 201 of the adjustable blade 200 is poor, and the use safety of the adjustable blade 200 is low.

In order to improve the mechanical properties of the shaft diameter 201 of the adjustable blade 200 while ensuring that the size of the shaft sleeve remains unchanged, as shown in Figures 1 to 4, the embodiment of the present invention discloses a shaft sleeve 100 for the adjustable blade 200, including a shaft sleeve body 101. By providing an opening 1012 on the mounting blind hole 1011 on the shaft sleeve body 101, and the opening 1012 is connected to the side wall of the shaft sleeve body 101, the width of the upper shaft diameter 2011 or the lower shaft diameter 2012 of the adjustable blade 200 can be effectively increased. By removing the redundant portion of the shaft sleeve 100 for constraining the upper shaft diameter 2011 or the lower shaft diameter 2012 of the adjustable blade 200, the inner and outer ring components of the aviation turbofan engine 300 are fully utilized to constrain the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 where the shaft sleeve is removed, so that the width of the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 is maximized while ensuring that the size of the shaft sleeve remains unchanged, thereby improving the mechanical properties of the shaft diameter 201 of the adjustable blade 200, such as strength and stiffness.

The shaft sleeve 100 for the adjustable blade 200 disclosed in the embodiment of the present invention will be specifically explained and illustrated below in conjunction with FIGS. 1 to 8 .

As shown in Figures 1 to 4, a mounting blind hole 1011 is provided on the sleeve body 101, so that when the upper shaft diameter 2011 or the lower shaft diameter 2012 of the adjustable blade 200 is installed on the sleeve 100, the upper shaft diameter 2011 or the lower shaft diameter 2012 of the adjustable blade 200 can be inserted into the mounting blind hole 1011 on the sleeve body 101, and adhesive is poured into the mounting blind hole 1011 to bond and fix the sleeve 100 to the upper shaft diameter 2011 or the lower shaft diameter 2012 of the adjustable blade 200.

It should be noted that the cross-sectional shape of the mounting blind hole 1011 matches the cross-sectional shape of the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200. In the present embodiment, the cross-sectional shape of the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 is approximately a rectangular shape, and the cross-sectional shape of the mounting blind hole 1011 on the sleeve body 101 is approximately a rectangular shape that is the same as the cross-sectional shape of the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200, so as to ensure that the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 can be inserted into the corresponding mounting blind hole 1011 of the sleeve body 101, thereby realizing the assembly between the shaft diameter 201 of the adjustable blade 200 and the sleeve 100.

At the same time, in order to increase the width of the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 and improve the mechanical properties such as the strength and stiffness of the shaft diameter 201 of the adjustable blade 200, as shown in Figure 1, at least one opening 1012 is provided on the mounting blind hole 1011, and the opening 1012 penetrates to the side wall of the sleeve body 101 along the length direction of the cross section of the mounting blind hole 1011, thereby forming a mounting groove 1013 on the side wall of the sleeve body 101 with an opening 1012. When the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 are inserted into the mounting groove 1013 of the corresponding sleeve body 101, the width of the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 can be extended to the opening 1012 position of the side wall of the sleeve body 101, and the inner and outer ring components of the aviation turbofan engine 300 are used to constrain the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 at the opening 1012 position of the side wall of the sleeve body 101, thereby achieving the purpose of increasing the width of the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 and improving the mechanical properties such as strength and stiffness of the shaft diameter 201 of the adjustable blade 200.

Of course, the number of openings 1012 provided on the installation blind hole 1011 can be adopted but is not limited to one. In order to further improve the mechanical properties of the shaft diameter 201 of the adjustable blade 200, as shown in FIG3, two openings 1012 are coaxially provided on the installation blind hole 1011, and the two openings 1012 are respectively penetrated along the length direction of the cross section of the installation blind hole 1011 to the side wall of the sleeve body 101 on the corresponding side of the opening 1012, thereby forming a mounting groove 1013 on the sleeve body 101 that penetrates along the radial direction of the sleeve body 101. When the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 are inserted into the mounting groove 1013 of the corresponding sleeve body 101, the width of the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200 can be extended to the opening 1012 position on both sides of the mounting groove 1013, thereby maximizing the width of the upper shaft diameter 2011 and the lower shaft diameter 2012 of the adjustable blade 200, and further improving the mechanical properties such as strength and stiffness of the shaft diameter 201 of the adjustable blade 200.

Further, in order to improve the bonding performance between the sleeve 100 and the adjustable blade 200, as shown in Figures 1 to 4, a plurality of drainage holes 1014 are provided on the sleeve body 101, and the drainage holes 1014 are connected to the mounting blind holes 1011, so that the adhesive flows out from the drainage holes 1014, thereby avoiding air from being mixed in the adhesive layer, and improving the bonding performance. Specifically, the number of drainage holes 1014 on the side wall and the bottom wall of the mounting groove 1013 can be one, two, three or more. It can be understood by those skilled in the art that the more the number of drainage holes 1014, the more adhesive flows out, the less effective adhesive remains in the mounting groove 1013, and the lower the strength of the sleeve 100; similarly, the larger the aperture of the drainage hole 1014, the more adhesive flows out, the less effective adhesive remains in the mounting groove 1013, and the lower the strength of the sleeve 100. In this embodiment, preferably, a drainage hole 1014 is respectively provided on the side wall and the bottom wall of the installation groove 1013, and the aperture of the drainage hole 1014 is 1 mm to 2 mm to ensure that the adhesive can flow out of the drainage hole 1014 smoothly, avoid air being mixed in the adhesive layer, and leave more effective adhesive in the installation groove 1013, thereby improving the bonding performance between the sleeve 100 and the adjustable blade 200.

Further, as shown in FIG. 2 and FIG. 4 , in order to facilitate the installation and positioning between the adjustable blade 200 and the sleeve 100 and prevent the adjustable blade 200 from being offset by the position of the opening 1012 on the sleeve body 101 when being installed, a limiting ring 102 is provided on the sleeve body 101. Specifically, the limiting ring 102 is sleeved on the notch end of the mounting groove 1013 on the sleeve body 101, so that the adjustable blade 200 can be constrained when being inserted into the mounting groove 1013 of the sleeve body 101 by the limiting ring 102, thereby avoiding the problem of the adjustable blade 200 being offset by the position of the opening 1012 on the sleeve body 101 when being installed. Among them, the material of the sleeve body 101 can be a metal material, a wear-resistant plastic material or a resin-based composite material. In addition, the limiting ring 102 can be designed as an integral structure with the sleeve body 101, or of course, a split structure design can be adopted. In this embodiment, preferably, the sleeve body 101 is made of metal material, and the limiting ring 102 is designed as an integral structure with the sleeve body 101 to improve the overall strength and rigidity of the sleeve 100, thereby ensuring the stability of the connection between the adjustable blade 200 and the inner and outer ring components of the aviation turbofan engine 300, and improving the safety of the adjustable blade. At the same time, the limiting ring 102 is only arranged on the sleeve body 101 installed on the upper shaft diameter 2011 of the adjustable blade 200, so that the limiting ring 102 can cooperate with the step hole in the outer ring component of the aviation turbofan engine 300 while playing the role of installation positioning, thereby improving the installation efficiency of the adjustable blade 200 and the inner and outer ring components of the aviation turbofan engine 300. The lower shaft diameter 2012 of the adjustable blade 200 can be installed and positioned with the sleeve 100 and the adjustable blade 200 by means of a positioning tool. Of course, a limiting ring 102 can also be provided on the sleeve body 101 of the lower shaft diameter 2012 of the adjustable blade 200 without using a positioning tool. In this case, it is only necessary to design the mounting hole of the inner ring component of the aviation turbofan engine 300 as a stepped hole matching the limiting ring 102, thereby saving installation costs and improving the installation efficiency of the adjustable blade 200.

As shown in FIG. 5 to FIG. 8 , the embodiment of the present invention further discloses an adjustable blade 200 , including a shaft diameter 201 and a guide vane 202 .

Among them, as shown in Figures 6 and 8, the shaft diameter 201 includes an upper shaft diameter 2011 connected to the outer ring component of the aviation turbofan engine and a lower shaft diameter 2012 connected to the inner ring component of the aviation turbofan engine, and the upper shaft diameter 2011 and the lower shaft diameter 2012 of the shaft diameter 201 are respectively provided with shaft sleeves, which are the shaft sleeves 100 for adjustable blades disclosed in the above embodiment, and therefore have all the technical effects of the above-mentioned shaft sleeves 100 for adjustable blades, which will not be repeated herein.

Meanwhile, as shown in FIG5 , the guide vane 202 includes at least one blade 2021, and the blade 2021 is arranged on the shaft diameter 201 along the length direction of the shaft diameter 201. In order to improve the overall stability of the adjustable blade 200, in this embodiment, the blade 2021 and the shaft diameter 201 adopt an integrated structure, and the material of the adjustable blade 200 adopts a resin-based composite material, thereby reducing the weight of the adjustable blade 200 and improving its vibration fatigue performance and anti-bending and torsion performance. Of course, the material of the adjustable blade 200 can also adopt other materials, such as metal materials such as aluminum alloy or plastic materials.

Of course, the number of blades 2021 of the guide vane 202 can be but is not limited to one. When the adjustable blade 200 is an edge shaft adjustable blade, the guide vane 202 includes one blade 2021, and the blade 2021 is arranged on the shaft diameter 201 along the length direction of the shaft diameter 201, that is, the long side of the blade 2021 is arranged parallel to the length direction of the shaft diameter 201, as shown in Figures 5 and 6. When the adjustable blade 200 is an intermediate shaft adjustable blade, the guide vane 202 includes two blades 2021, and the two blades 2021 are arranged oppositely on the shaft diameter 201, that is, the long sides of the two blades 2021 are arranged parallel to the length direction of the shaft diameter 201, and the two blades 2021 are coplanar, as shown in Figures 7 and 8. It should be noted that, in this embodiment, when the adjustable blade 200 is an intermediate shaft adjustable blade, as shown in Figure 8, preferably, a sleeve 100 with a through mounting groove 1013 is arranged along the radial direction of the sleeve body 101 to maximize the width of the shaft diameter 201 of the intermediate shaft adjustable blade, thereby effectively improving the mechanical properties of the intermediate shaft adjustable blade.

Furthermore, a test experiment was carried out on the mechanical properties of the adjustable blade after the shaft sleeve 100 disclosed in the embodiment of the present invention was set, and a comparative analysis was conducted with the mechanical properties of the adjustable blade after the traditional shaft sleeve was set, as shown in Figure 10, wherein the solid line is the bending and torsion performance test curve of the adjustable blade disclosed in the embodiment of the present invention, and the dotted line is the bending and torsion performance test curve of the traditional adjustable blade. It can be seen from the curve comparison results in the figure that, under the condition that other conditions of the adjustable blade remain unchanged, the maximum bending and torsion failure load of the adjustable blade disclosed in the embodiment of the present invention is 2018N, while the maximum bending and torsion failure load of the traditional adjustable blade is 1738N. The maximum bending and torsion failure load of the adjustable blade after adopting the shaft sleeve 100 disclosed in the embodiment of the present invention increases by 17.8%, and relevant technical personnel in the field can understand that in the load-displacement curve in Figure 10, the greater the slope of the curve, the greater the stiffness of the adjustable blade. It can be seen from Figure 10 that the slope of the bending and torsion performance test curve of the adjustable blade disclosed in the embodiment of the present invention is greater than the slope of the bending and torsion performance test curve of the traditional adjustable blade. Therefore, the stiffness of the adjustable blade disclosed in the embodiment of the present invention is greater than the stiffness of the traditional adjustable blade. It can be seen that the mechanical properties of the adjustable blade disclosed in the embodiment of the present invention are significantly improved compared with the mechanical properties of the traditional adjustable blade. It should be noted that the above-mentioned mechanical property test experiment is only for the method of setting a through-type mounting groove 1013 on the shaft sleeve 100 shown in Figures 3 and 4 and is used for the bending and torsion experiment on the edge shaft adjustable blade. For the bending and torsion test of the edge shaft adjustable blade using the shaft sleeve 100 shown in Figures 1 and 2, the test results are similar to those in Figure 10, that is, the stiffness of the adjustable blade is greater than that of the traditional adjustable blade, and the mechanical properties of the adjustable blade are greatly improved compared to the mechanical properties of the traditional adjustable blade. At the same time, the mechanical property test results of the intermediate shaft adjustable blade are basically consistent with the mechanical property test results of the edge shaft adjustable blade, and will not be repeated in this article.

As shown in FIG9 , an embodiment of the present invention further discloses an aviation turbofan engine 300, including adjustable blades. The adjustable blades are the adjustable blades 200 disclosed in the above embodiment, and therefore have all the technical effects of the above adjustable blades 200, which will not be described in detail herein.

The terms "first" and "second" and the like in the specification and claims of the present invention and the above drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but may include steps or units that are not listed.

The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims (12)

1. A sleeve for an adjustable blade, comprising: A shaft sleeve body (101), wherein the shaft sleeve body (101) is provided with a mounting blind hole (1011) for mounting an upper shaft diameter (2011) or a lower shaft diameter (2012) of the adjustable blade (200), wherein the mounting blind hole (1011) comprises at least one opening (1012), and the opening (1012) is arranged to be connected to a side wall of the shaft sleeve body (101) to form a mounting groove (1013) for inserting the upper shaft diameter (2011) or the lower shaft diameter (2012) of the adjustable blade (200). 2. The sleeve for adjustable blades according to claim 1 is characterized in that the mounting blind hole (1011) includes two coaxially arranged openings (1012), and the two openings (1012) are respectively coaxially arranged through the side walls of the sleeve body (101) to form the mounting groove (1013). 3. The sleeve for an adjustable blade according to claim 1, characterized in that the sleeve body (101) is bonded to the upper shaft diameter (2011) or the lower shaft diameter (2012) of the adjustable blade (200) by an adhesive. 4. The sleeve for adjustable blades according to claim 3 is characterized in that a plurality of drainage holes (1014) are provided on the sleeve body (101), and the drainage holes (1014) are connected to the mounting blind holes (1011) so that the adhesive flows out from the drainage holes (1014). 5. The shaft sleeve for adjustable blades according to claim 1, characterized in that a limiting ring (102) is provided on the shaft sleeve body (101) for facilitating the installation of the adjustable blade (200). 6. The shaft sleeve for adjustable blades according to claim 5, characterized in that the limiting ring (102) is arranged on the shaft sleeve body (101) for being installed on the upper shaft diameter (2011) of the adjustable blade (200). 7. The shaft sleeve for adjustable blades according to claim 5, characterized in that the limiting ring (102) and the shaft sleeve body (101) are an integrated structure. 8. The shaft sleeve for adjustable blades according to any one of claims 1 to 7, characterized in that the material of the shaft sleeve body (101) is a metal material, a wear-resistant plastic material or a resin-based composite material. 9. An adjustable blade, characterized by comprising: A shaft diameter (201), the shaft diameter (201) comprising an upper shaft diameter (2011) for connecting to an outer ring component of an aviation turbofan engine and a lower shaft diameter (2012) for connecting to an inner ring component of the aviation turbofan engine, and the upper shaft diameter (2011) and the lower shaft diameter (2012) of the shaft diameter (201) are respectively sleeved with a shaft sleeve (100) for an adjustable blade according to any one of claims 1 to 8; A guide plate (202), wherein the guide plate (202) comprises at least one blade (2021), and the blade (2021) is arranged on the shaft diameter (201) along the length direction of the shaft diameter (201). 10. The adjustable blade according to claim 9, characterized in that the guide vane (202) comprises two blades (2021), and the two blades (2021) are arranged opposite to each other on the shaft diameter (201). 11. The adjustable blade according to claim 9, characterized in that the blade (2021) and the shaft diameter (201) are an integrated structure; and/or, The material of the adjustable blade (200) is a resin-based composite material. 12. An aviation turbofan engine, characterized by comprising an adjustable blade (200) as claimed in any one of claims 1 to 11.