Composite material blade balance structure and fan blade

Abstract

The composite material blade balance structure is arranged on a composite material blade body, the composite material blade body comprises a front edge metal reinforcing edge, the balance structure comprises a tail edge metal reinforcing edge, the tail edge metal reinforcing edge is arranged on the tail edge of the blade body, and the tail edge metal reinforcing edge and the blade body form a complete blade profile. The trailing edge metal reinforcement edge includes a coping region as a balanced de-material region. According to the structure, the balance material removing area can be provided under the condition that the function of the composite material fan blade is not affected, and the balance material removing requirement is met. The utility model further provides a fan blade and an aero-engine.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of aero-engine, specifically to the field of composite blade structure. BACKGROUND

[0002] In the processing and manufacturing process of the composite material fan blade of the aero-engine, due to the material characteristics of the composite material itself and the limitation of the processing technology of different suppliers, the profile of the formed composite blade is difficult to be as accurate as the metal blade, which will lead to a large difference in the final state of each composite material fan blade. For the fan blade, the rotor balance needs to be ensured. SUMMARY

[0003] An object of the utility model is to provide a composite blade balance structure, which can provide a balance material removal area without affecting the function of the composite material fan blade itself, to meet the balance material removal requirement.

[0004] The composite blade balance structure is arranged on the composite blade body, the composite blade body includes a leading edge metal reinforcing edge, the balance structure includes a trailing edge metal reinforcing edge arranged at the trailing edge of the blade body and forming a complete airfoil with the blade body. The trailing edge metal reinforcing edge includes a grinding area as a balance material removal area.

[0005] In one or more embodiments, the trailing edge metal reinforcing edge is bonded to the trailing edge of the blade body.

[0006] In one or more embodiments, the leading edge metal reinforcing edge includes a first part located on the pressure surface side of the blade body, a second part located on the suction surface side of the blade body, and a connecting edge connecting the first part and the second part.

[0007] In one or more embodiments, the trailing edge metal reinforcing edge is a T-shaped structure including a main body part and a protruding part, a surface of the main body part forms part of the pressure surface and the suction surface of the blade body, and the protruding part is located inside the blade body.

[0008] In one or more embodiments, a groove is provided on the trailing edge side of the blade body for cooperation with the protruding part.

[0009] In one or more embodiments, the top edge of the trailing edge metal reinforcing edge is located.

[0010] Another object of the utility model is to provide a fan blade including the above-mentioned composite blade balance structure.

[0011] Another object of the utility model is to provide an aero-engine including the above-mentioned fan blade.

[0012] The tail edge metal reinforcing edge of the composite blade balance structure and the original composite material fan blade form a complete fan blade airfoil together, so as to ensure the aerodynamic performance; the problem of excessive unbalance of different composite material fan blades of the same configuration can be effectively solved by increasing the grinding area as a balance material removal area without affecting the function of the composite material fan blade itself. BRIEF DESCRIPTION OF DRAWINGS

[0013] The above and other features, properties, and advantages of the present application will become more apparent by reference to the following description of embodiments in conjunction with the accompanying drawings wherein:

[0014] Figure 1 is a schematic diagram of a mainstream composite material fan blade structure;

[0015] Figure 2 is a schematic diagram of the relative relationship between the leading edge metal reinforcing edge and the blade body;

[0016] Figure 3 is a schematic diagram of a composite material blade balance structure;

[0017] Figure 4 is a schematic diagram of the relative relationship between the leading edge metal reinforcing edge, the tail edge metal reinforcing edge and the blade body;

[0018] Figure 5 is a schematic diagram of the airfoil at a certain blade height of the blade;

[0019] Figure 6 is an enlarged view of the cross section of the leading edge metal reinforcing edge;

[0020] Figure 7 is an enlarged view of the cross section of the tail edge metal reinforcing edge;

[0021] Figure 8 is a connection relationship diagram of the tail edge metal reinforcing edge and the blade body;

[0022] Figure 9 is a schematic diagram of the grinding area. DETAILED DESCRIPTION

[0023] The present application will be further described below in conjunction with specific embodiments and drawings, and more details are set forth in the following description in order to fully understand the present application, but the present application can obviously be implemented in various other ways different from the description, and those skilled in the art can make similar generalizations and deductions according to actual application conditions without departing from the connotation of the present application, so the protection scope of the present application should not be limited by the content of the specific embodiments.

[0024] It should be noted that these and other subsequent drawings are only as an example, which is not drawn in accordance with the conditions of the same scale, and should not be taken as the actual required protection of the present invention constitute a limit.

[0025] Fan blades are used to provide the main thrust of an aero-engine. Composite fan blades are composed of a variety of materials, usually including reinforcing fibers (such as carbon fibers, glass fibers, etc.) and matrix materials (such as resins, plastics, etc.). This design enables the fan blade to have the advantages of light weight, high performance, corrosion resistance, fatigue resistance, etc. while ensuring strength and toughness.

[0026] For large-size composite fan blades, rotor balancing has always been a problem that needs to be solved urgently for aero-engines. In actual engineering practice, the weight distance difference of different pieces of composite blades of the same configuration can reach tens of thousands of g.mm, thereby affecting the balance of the rotor.

[0027] The commonly used material removal balancing method will damage the integrity of the composite structure, causing a decrease in strength performance. For example, the thickness of different parts of the blade is optimized, or a local hollow or hollow structure is used. This will undoubtedly make the rotor imbalance problem of the composite fan blade more prominent.

[0028] As shown in Figures 1-2 , the current mainstream composite fan blade structure includes a composite fan blade body 11 and a leading edge metal reinforcing edge 12 arranged at the leading edge A of the blade. The composite fan blade body is a full composite part that forms the main structure of the composite blade, and the leading edge metal reinforcing edge is mainly made of stainless steel and titanium alloy. Its main function is to protect the blade edge and prevent foreign objects from being sucked into the blade during engine operation, causing damage to the composite blade body.

[0029] On the basis of this mature composite fan blade structure, the following content proposes a composite blade balancing structure for adjusting and correcting the unbalanced moment when the rotor rotates.

[0030] As shown in Figures 3-4 , the composite blade balancing structure includes a trailing edge metal reinforcing edge 13 arranged at the trailing edge B of the blade body 11. The trailing edge metal reinforcing edge 13 and the blade body 11 form Figure 5 a complete airfoil as shown, i.e. the trailing edge metal reinforcing edge 13 is not protruding relative to the pressure surface and the suction surface of the blade body, forming a smooth structure.

[0031] In this way, the leading edge A of the composite fan blade 10 is provided with the leading edge metal reinforcing edge 12, and the trailing edge B is provided with the trailing edge metal reinforcing edge 13, which is consistent with the blade airfoil and does not affect the aerodynamic performance of the blade.

[0032] In some embodiments, the trailing edge metal reinforcement 13 is bonded to the trailing edge B of the blade body 11, and the trailing edge metal reinforcement 13 and the blade body 11 are integrated by filling with adhesive film. After bonding, the composite material fan blade body 11, together with the leading edge metal reinforcement 12 and the trailing edge metal reinforcement 13, forms a complete blade shape.

[0033] In some embodiments, the leading edge metal reinforcing edge 12 is a thin-walled internal cavity structure, such as... Figure 6 The enlarged view of the leading edge C shown includes a first portion 121 located on the pressure side of the blade body, a second portion 122 located on the suction side of the blade body, and a connecting edge 123 connecting the first portion 121 and the second portion 122. This design increases the bonding area between the reinforcing edge and the composite blade body 11, preventing the leading edge metal reinforcing edge 12 from detaching from the composite blade body 11 when the leading edge cuts into external objects during fan blade operation. The first portion 121 and the second portion 122 of the leading edge metal reinforcing edge 12 are relatively thin wings, which are more easily deformed during actual processing, making the gap between the leading edge metal reinforcing edge 12 and the blade body 11 smaller and increasing the difficulty of bonding.

[0034] Compared to the leading-edge reinforcing edge 12, the trailing-edge metal reinforcing edge 13 does not have the structural requirement to withstand foreign object impacts. Therefore, it does not need to be designed as a thin-walled airfoil structure like the leading-edge reinforcing edge, but can instead use a "T"-shaped structure design, such as... Figure 7 The enlarged view of the trailing edge D shown.

[0035] The T-shaped structure includes a main body 131 and a protrusion 132. The surface of the main body 131 forms part of the pressure surface and suction surface of the blade body, and the protrusion 132 is located inside the blade body 11. Correspondingly, a groove 110 is provided on the trailing edge B side of the blade body 11 for engaging with the protrusion 132.

[0036] Compared to the thin-walled leading edge reinforcement, the "T"-shaped trailing edge metal reinforcement has a significantly improved overall rigidity, thus greatly improving its manufacturability. The "T"-shaped metal reinforcement effectively avoids deformation caused by residual stress in thin-walled parts such as the leading edge reinforcement, as well as assembly problems caused by deformation.

[0037] Because the composite blade balancing structure needs to provide a balancing material removal area for the fan blade to meet the balancing material removal requirements of the composite fan blade, the trailing edge metal reinforcing edge 13 also includes a grinding area 130 as a balancing material removal area. Figure 9 In the illustrated embodiment, the grinding area 130 is located at the top edge of the trailing edge metal reinforcing edge 13, i.e., the upper right corner of the figure. In other embodiments, the grinding area 130 may also be located at other positions. The trailing edge metal reinforcing edge 13 may also have multiple grinding areas 130 located at different positions.

[0038] When two pieces of composite fan blades have too large unbalance due to different supplier process and raw material, the fan blades can be balanced by properly grinding the tail edge metal reinforcing edge of the blades, so that the unbalance of any two pieces of composite fan blades can be controlled within an acceptable small amount before the rotor is assembled.

[0039] In the specific process implementation, first, the composite fan blade body 11 is cured and formed to the net size and then, as shown in the figure, the relative positions of the blade body 11 and the front edge metal reinforcing edge 12 and the tail edge metal reinforcing edge 13 are positioned, and the film is filled between the composite fan blade and the reinforcing edge and cured and formed. Figures 5-7

[0040] After the front-tail edge reinforcing edge bonding is completed, the blade balancing work is performed, the blade mass, centroid and weight distance are measured, the tail edge metal reinforcing edge of the blade is ground to remove the material area according to the difference between the measured weight distance and the theoretical weight distance, and the composite fan blade weight distance is ground to be within the theoretical allowable weight distance tolerance range.

[0041] The tail edge metal reinforcing edge of the above-mentioned composite blade balancing structure and the original composite fan blade form a complete fan blade airfoil together to ensure the aerodynamic performance; further, without affecting the function of the composite fan blade itself, by increasing the tail edge metal reinforcing edge, the problem of too large unbalance of different composite fan blades of the same configuration can be effectively solved.

[0042] It should be noted that the words "first", "second" and the like used in the above description are used to limit the parts only for the convenience of distinguishing the corresponding parts, and have no special meaning unless otherwise stated, and therefore cannot be understood as a limitation on the protection scope of the present application.

[0043] In the description of the present application, it should be understood that the orientation words such as "front, rear, upper, lower, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and in the absence of the opposite description, these orientation words do not indicate and imply that the indicated device or element must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection scope of the present application; the orientation words "inner, outer" refer to the inner and outer relative to the contour of each part itself.

[0044] ​Also, certain terminology has been used in the description for the purpose of reference only. As one skilled in the art will appreciate, the terms "one embodiment," "an embodiment,” "some embodiments,” and "one alternative” are not intended to refer to the same embodiments or to a single alterative unless explicitly so identified. Rather, the terms are used solely to distinguish different embodiments. Moreover, the use of the terms first, second, etc., merely designate the different steps in the methods for purposes of clarity and are not intended to be limiting.

[0045] The utility model discloses although the above-mentioned preferable embodiment is disclosed, but it is not used to limit the utility model, and any one skilled in the art can make possible change and modification without departing from the spirit and scope of the utility model. Therefore, all the modifications, equivalent changes and modifications of the above embodiment according to the technical essence of the utility model, all fall into the protection scope defined in the utility model claim without departing from the technical scheme of the utility model.

Claims

1. A composite blade balance structure provided on a composite blade body, the composite blade body comprising a leading edge metal stiffened edge, characterised in that, The balancing structure comprises: a trailing edge metal strip provided at a trailing edge of the blade body and forming a complete airfoil with the blade body, the trailing edge metal strip comprising a scarf region as a balancing material removal region.

2. The composite material blade balance structure according to claim 1, wherein The trailing edge metal strip is bonded to the trailing edge of the blade body.

3. The composite material blade balance structure according to claim 1, wherein The leading edge metal strip comprises a first portion on a pressure side of the blade body, a second portion on a suction side of the blade body, and a connecting edge connecting the first portion and the second portion.

4. The composite material blade balance structure according to claim 3, wherein The trailing edge metal strip is in a T-shaped structure, comprising a main body portion and a protruding portion, a surface of the main body portion forms a part of the pressure side and the suction side of the blade body, and the protruding portion is inside the blade body.

5. The composite material blade balance structure according to claim 4, wherein The trailing edge of the blade body is provided with a groove for cooperating with the protruding portion.

6. The composite material blade balance structure according to claim 1, wherein The top edge of the trailing edge metal strip.

7. A fan blade characterised in that, A composite blade balancing structure as claimed in any one of claims 1-6.

8. An aeroengine characterised in that, A fan blade as claimed in claim 7.

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