Composite material fan blade

Abstract

The composite material fan blade comprises a blade body, a metal reinforcing edge, a cushion layer and a connecting piece, and the metal reinforcing edge is arranged on the front edge and / or the tail edge of the blade body; the cushion layer is located between the blade body and the metal reinforcing edge. The connecting piece is used for connecting the blade body, the metal reinforcing edge and the cushion layer, and connecting holes matched with the connecting piece are formed in the blade body, the metal reinforcing edge and the cushion layer. According to the composite material fan blade structure, the mechanical connection mode of the connecting pieces and the connecting holes is adopted, the problems that a traditional bonding technology is unstable and the connection strength does not reach the standard can be solved, and the composite material blade body and the metal reinforcing edge are connected more stably.

Description

TECHNICAL FIELD

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

[0002] The mainstream composite fan blade includes a composite fan blade body and a metal reinforcing edge. The reinforcing edge and the composite blade are mainly bonded by various adhesives, but the bonding stability and bonding strength have always restricted the development of the composite blade. SUMMARY

[0003] One object of the utility model is to provide a composite fan blade, which makes the blade body of the composite material and the metal reinforcing edge have more stable connection.

[0004] To achieve the above-mentioned purpose, the composite fan blade includes a blade body, a metal reinforcing edge, a pad layer, and a connecting piece. The metal reinforcing edge is arranged on the leading edge and / or the trailing edge of the blade body. The pad layer is located between the blade body and the metal reinforcing edge. The connecting piece is used to connect the blade body, the metal reinforcing edge, and the pad layer. The blade body, the metal reinforcing edge, and the pad layer are all provided with connecting holes matched with the connecting piece.

[0005] In one or more embodiments, the connecting piece includes an external thread bolt, an internal thread bolt, and a bushing. The bushing is located in the connecting hole. The external thread bolt includes an external thread. The internal thread bolt includes an internal thread matched with the external thread. The external thread bolt and the internal thread bolt are jointly located in the bushing.

[0006] In one or more embodiments, the bushing is a rubber bushing.

[0007] In one or more embodiments, the external thread bolt and the internal thread bolt are titanium alloys.

[0008] In one or more embodiments, the external thread bolt and the internal thread bolt both include a plugging part located at the end, which is in contact with the metal reinforcing edge.

[0009] In one or more embodiments, the metal reinforcing edge includes a blade basin side reinforcing edge and a blade back side reinforcing edge. Both the blade basin side reinforcing edge and the blade back side reinforcing edge are provided with the connecting hole.

[0010] In one or more embodiments, the pad layer is a rubber pad layer.

[0011] In one or more embodiments, the blade body, the metal reinforcing edge, and the pad layer are uniformly provided with a plurality of connecting holes in the direction of blade height.

[0012] The composite fan blade adopts a mechanical connection mode of the connecting piece and the connecting hole, can solve the problems of unstable traditional bonding process and substandard connection strength, and makes the blade body and the metal reinforcing edge have more stable connection. 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.

[0014] Figure 1 is a schematic view of a traditional composite fan blade;

[0015] Figure 2 is a schematic view of a leading edge metal reinforcing edge and a blade body;

[0016] Figure 3 is a schematic view of a leading edge metal reinforcing edge, a pad layer, and a blade body;

[0017] Figure 4 is a schematic view of a connecting hole;

[0018] Figure 5 is a schematic view of an external thread bolt, an internal thread bolt, and a bushing;

[0019] Figure 6 is a schematic view of a connecting piece;

[0020] Figure 7 is a schematic view of a composite fan blade according to the present disclosure. DETAILED DESCRIPTION

[0021] The present application will be further described by reference to specific embodiments and to the accompanying drawings, which set forth a larger number of specific details in order to provide a thorough understanding of the present application. However, the present application can be practiced with the claimed scope and without using some or all of these specific details, and the scope of the present application is not intended to be limited to the described embodiments.

[0022] It should be noted that these and other accompanying drawings are merely illustrative, not drawn to scale, and should not be used to limit the scope of the claimed application.

[0023] Fan blades are one of the most important components of modern aeroengines, located near the engine air inlet. The fan blades suck in a large amount of air and compress and accelerate the incoming air to provide sufficient airflow and thrust for the engine.

[0024] The design of the fan blades has a significant impact on the efficiency of the engine.

[0025] Figure 1 and Figure 2 The current mainstream composite fan blade structure is shown, which includes a composite blade body 11 and a leading edge metal reinforcing edge 12.

[0026] The composite fan blade body is a full composite part, forming the main structure of the composite blade. Since the leading edge part of the fan blade bears the largest airflow impact force, increasing the leading edge metal reinforcing edge 12 can improve the damage resistance of the blade leading edge. The leading edge metal reinforcing edge is mainly made of stainless steel and titanium alloy, and its main function is to protect the blade edge and prevent foreign objects from being sucked into the blade during engine operation, thereby causing damage to the composite blade body. In addition, metal materials have good high-temperature resistance and corrosion resistance, so they can also enhance the corrosion resistance and high-temperature resistance of the fan blade.

[0027] The composite blade body 11 and the leading edge metal reinforcing edge 12 are generally mainly bonded using various adhesives, and the bonding strength affects the overall strength of the blade. In addition, the leading edge metal reinforcing edge is often damaged by sand, rain and other external impacts during operation, and under the traditional gluing scheme, if the leading edge metal reinforcing edge is damaged, the entire blade is close to scrap, so the glued blade also has a high cost.

[0028] Based on this, the present disclosure proposes a composite fan blade, which adopts a mechanical connection structure to make the blade body and the metal reinforcing edge have a more stable connection relationship.

[0029] Referring to Figures 3 to 4 , the composite fan blade includes a blade body 11, a metal reinforcing edge 12 and a pad layer 13, the metal reinforcing edge 12 is arranged on the leading edge and / or the trailing edge of the blade body, and the pad layer 13 is located between the blade body 11 and the metal reinforcing edge 12. The pad layer 13 can be a rubber pad layer, which is sandwiched between the leading edge metal reinforcing edge and the composite blade body. It can not only avoid the slippage between the reinforcing edge and the blade body and the internal pores of the bonding area caused by the flow of the adhesive during the bonding process, but also effectively reduce the transmission of impact energy to the composite blade after the blade leading edge is impacted by external objects. Such impact load is often the main load of blade damage.

[0030] The connecting piece 14 is used to connect the blade body 11, the metal reinforcing edge 12 and the pad layer 13, and the blade body 11, the metal reinforcing edge 12 and the pad layer 13 are all provided with connecting holes 15 matched with the connecting piece, as shown in Figure 3 .

[0031] As shown in Figure 5 and Figure 6As shown, the connecting member 14 includes an outer threaded bolt 141, an inner threaded bolt 142 and a bushing 143, the bushing 143 is located in the connecting hole 15, the outer threaded bolt 141 includes the outer thread 41, the inner threaded bolt 142 includes the inner thread 42, both are connected in opposite directions perpendicular to the blade surface and are located in the bushing 143.

[0032] In some embodiments, the bushing 143 is a rubber bushing. In actual work of the blade, it needs to bear a huge centrifugal load. Only the hard connection between the metal bolt and the blade can easily cause the extrusion stress between the bolt and the composite blade to be overloaded, resulting in delamination damage of the composite blade. Therefore, a rubber bushing is designed between the metal bolt and the blade to effectively disperse the extrusion stress at the connecting hole of the bolt and the blade.

[0033] The outer threaded bolt 141 and the inner threaded bolt 142 each include a sealing portion 40 located at the end, which is in contact with the metal reinforcing edge 12 to improve the fastening effect.

[0034] The outer threaded bolt 141 and the inner threaded bolt 142 are preferably made of titanium alloy to minimize galvanic corrosion between the metal and the composite. The metal reinforcing edge 12 can also be made of titanium alloy.

[0035] The metal reinforcing edge 12 includes a blade basin side reinforcing edge 121 and a blade back side reinforcing edge 122, both of which are provided with aligned connecting holes 15. The outer threaded bolt 141 passes through one of the blade basin side reinforcing edge 121 and the blade back side reinforcing edge 122, and the inner threaded bolt 142 passes through the other one.

[0036] Before installation, the connecting holes 15 are machined on the blade body 11, the metal reinforcing edge 12 and the pad 13, and the three parts are aligned at several radial connecting holes.

[0037] Then the rubber bushing is inserted into the aligned mounting hole 15 of the blade body 11, the metal reinforcing edge 12 and the pad 13, and then the outer threaded bolt 141 and the inner threaded bolt 142 are screwed in from two directions.

[0038] Finally, after all the fastening parts are installed along the radial direction, the fixing of the entire leading edge metal reinforcing edge and the composite blade body is completed.

[0039] It can be understood that the outer threaded bolt 141 and the inner threaded bolt 142 can be disassembled and separated, so that the mechanical connection scheme adopted by the above structure makes the blade have good maintainability. When the leading edge reinforcing edge of the blade is damaged, the outer threaded bolt 141 and the inner threaded bolt 142 can be disassembled, and the leading edge cover can be replaced. When the composite blade body is damaged, the leading edge can also be recycled.

[0040] The composite fan blade has the following advantages:

[0041] (1) The mechanical connection structure is adopted, the two parts are directly connected by using a metal connecting piece through punching in the assembled metal reinforcing edge and the blade body in the radial direction, and the connection structure is more stable than the adhesive connection;

[0042] (2) In order to solve the material delamination phenomenon caused by excessive local stress during mechanical connection of the composite part, a rubber bushing is installed between the connecting piece and the blade body;

[0043] (3) A rubber pad is arranged between the reinforcing edge and the blade body, which can reduce the impact force transmitted to the blade body when the reinforcing edge is subjected to impact load such as bird strike, compared with the traditional adhesive connection, the mechanical connection can also ensure that different parts are replaced very conveniently after the blade is damaged, and the maintenance cost of the blade is minimized.

[0044] 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 position relationship shown in the drawings, which is 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, therefore it 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 of the contour of each component itself.

[0045] Meanwhile, specific words are used in the present application to describe the embodiments of the present application. As "one embodiment", "an embodiment" and / or "some embodiments" mean a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "an embodiment" or "one embodiment" or "an alternative embodiment" mentioned in different positions in the specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be properly combined.

[0046] Although the utility model discloses the above-mentioned preferable embodiment, it is not used to limit the utility model, and any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the utility model. Therefore, any modification, equivalent change and modification made to the above-mentioned embodiment according to the technical essence of the utility model without departing from the technical scheme of the utility model, all fall within the protection scope defined by the claims of the utility model.

Claims

1. A composite fan blade, characterized by, The utility model relates to a blade structure, comprising: a blade body; a metal reinforcing edge arranged on a leading edge and / or a trailing edge of the blade body; a pad layer between the blade body and the metal reinforcing edge; and a connecting piece for connecting the blade body, the metal reinforcing edge and the pad layer, each of the blade body, the metal reinforcing edge and the pad layer being provided with a connecting hole matched with the connecting piece.

2. The composite fan blade of Claim 1, wherein The connecting piece comprises an externally threaded bolt, an internally threaded bolt and a bushing, the bushing being located in the connecting hole, the externally threaded bolt comprising an external thread, the internally threaded bolt comprising an internal thread matched with the external thread, the externally threaded bolt and the internally threaded bolt being jointly located in the bushing.

3. The composite fan blade of Claim 2, wherein The bushing is a rubber bushing.

4. The composite fan blade of Claim 2, wherein The externally threaded bolt and the internally threaded bolt are titanium alloys.

5. The composite fan blade of Claim 2 wherein, The externally threaded bolt and the internally threaded bolt each comprise a sealing portion at an end portion, the sealing portion being in contact with the metal reinforcing edge.

6. The composite fan blade of claim 1, wherein The metal reinforcing edge comprises a pressure surface side reinforcing edge and a suction surface side reinforcing edge, each of the pressure surface side reinforcing edge and the suction surface side reinforcing edge being provided with the connecting hole.

7. The composite fan blade of claim 1, wherein The pad layer is a rubber pad layer.

8. The composite fan blade of claim 1, wherein The blade body, the metal reinforcing edge and the pad layer are uniformly provided with a plurality of connecting holes in a blade height direction.

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