Fan blade mounting structure, fan blade mounting method and open type rotor engine

Abstract

The invention relates to a fan blade mounting structure, a fan blade mounting method and an open rotor engine. The fan blade mounting structure is used for mounting a fan blade on a hub, the fan blade comprises a blade handle, the blade handle is mounted on the hub through the fan blade mounting structure, the fan blade mounting structure comprises a bearing device, and the bearing device comprises a bearing inner ring, a rolling body and a bearing outer ring from inside to outside in the radial direction; the two ends of the rolling body are respectively connected with the bearing inner ring and the bearing outer ring in a rolling manner; the bearing inner ring is used for being in interference fit with the blade handle, and the bearing outer ring is used for being connected with the inner wall of a hole of a hub; the bearing outer ring comprises an upper section, a middle section and a lower section which are sequentially distributed in the axial direction.

Description

Technical Field

[0001] The invention relates to a fan blade mounting structure, a mounting method and an open rotor engine. Background Art

[0002] The open rotor engine is a new type of engine between turboprops and turbofans, also known as propfan engines or unducted fan engines. The open rotor engine can achieve a very large bypass ratio (30-90), has higher propulsion efficiency than turbofan engines under high subsonic cruise conditions, and has a fuel consumption rate that is 25%-30% lower than that of current engines in service. It is an important technical approach to achieve aviation carbon emission reduction.

[0003] The open fan blades are set into the hub hole through the mounting structure, and the blades can rotate in the hub hole under the drive of the variable pitch mechanism. The open fan blades have a long radius and a large sweep angle of the leading and trailing edges. The bending moment caused by the misalignment between the blade mass center and the blade handle rotation axis at different pitch angles is also large. The moving blade mounting structure needs to bear huge axial force (corresponding to centrifugal force) and radial force (corresponding to bending moment), as well as the torque transmitted by the variable pitch mechanism.

[0004] The fan components of an open rotor engine do not have an external casing. The airworthiness clauses require that the open fan blades and their mounting structures still have sufficient structural integrity and safety when they are subjected to unexpected situations such as bird strikes. Under extreme operating conditions, the fan blades may partially fly off after being hit by foreign objects, which may cause the engine to shut down. At this time, the blades need to be able to rotate and maintain an appropriate pitch angle to ensure flight safety. Specifically, during the operation of the engine, it is inevitable that the fan rotor will generate huge impact and unbalanced loads due to unavoidable reasons such as foreign object inhalation and fatigue. The impact and unbalanced loads generated by the fan rotor are transmitted to the hub through the moving blade mounting structure, and then transmitted to the load-bearing casing through the fulcrum. Excessive impact loads may cause jamming between the blade stalk and the hub hole, which may cause the fan blades to be located at an unfavorable pitch angle, endangering flight safety. Therefore, the fan blades should still be able to rotate and maintain an appropriate pitch angle under impact and unbalanced loads.

[0005] Therefore, there is a need in the art for a fan blade mounting structure, mounting method, and open rotor engine to achieve a fan blade mounting structure with heavy load and high impact bearing capacity to ensure sufficient functional integrity after being subjected to large loads. Summary of the invention

[0006] An object of the present invention is to provide a fan blade mounting structure.

[0007] An object of the present invention is to provide a mounting method.

[0008] An object of the present invention is to provide an open rotor engine.

[0009] According to a first aspect of the present invention, a fan blade mounting structure is used to mount a fan blade on a wheel hub, the fan blade includes a blade handle, the blade handle is mounted on the wheel hub through the fan blade mounting structure, the fan blade mounting structure includes: a bearing device, radially from the inside to the outside including: a bearing inner ring, a rolling body, and a bearing outer ring, the rolling body rollingly connects the bearing inner ring and the bearing outer ring at both ends; the bearing inner ring is used to have an interference fit with the blade handle, and the bearing outer ring is used to connect with the inner wall of the hole of the wheel hub; wherein the bearing outer ring includes an upper section, a middle section and a lower section sequentially distributed along the axial direction, the upper section of the bearing outer ring cooperates with a pressing member, the middle section and the lower section cooperate with the inner wall of the hole of the wheel hub, a first mechanical weak portion is provided between the upper section and the middle section of the bearing outer ring, and the lower section has a second mechanical weak portion; the middle section has a first spherical joint surface, the inner wall of the hole of the wheel hub has a second spherical joint surface, the first spherical joint surface and the second spherical joint surface cooperate with each other to form a spherical joint pair, and an energy absorption layer is provided between the first spherical joint surface and the second spherical joint surface.

[0010] In one or more embodiments of the fan blade mounting structure, the fan blade mounting structure is coaxial with the stalk of the fan blade and can withstand axial force and radial force from the fan blade at the same time.

[0011] In one or more embodiments of the fan blade mounting structure, the rolling body includes an inclined cylindrical rolling body and a ball rolling body, and the inclined cylindrical rolling body and the ball rolling body are arranged axially to jointly support the blade handle.

[0012] In one or more embodiments of the fan blade mounting structure, the energy absorbing layer is an artificial cartilage foam material.

[0013] In one or more embodiments of the fan blade mounting structure, when the fan is in a normal state, the outer ring of the bearing is relatively fixed to the inner wall of the hole of the hub, and the blade handle can rotate relative to the hub through the rolling body.

[0014] In one or more embodiments of the fan blade mounting structure, when the impact load transmitted from the fan blade to the bearing outer ring exceeds a threshold value, the first mechanically weak portion and / or the second mechanically weak portion of the bearing outer ring fails, and the bearing outer ring is now connected to the inner wall of the hole of the wheel hub via a ball joint pair formed by the inner wall of the hole of the wheel hub and the middle section, so that the bearing outer ring and the inner wall of the hole of the wheel hub can rotate and tilt relative to each other.

[0015] In one or more embodiments of the fan blade mounting structure, when the impact load transmitted from the fan blade to the bearing outer ring exceeds a threshold value, the first mechanically weak portion and / or the second mechanically weak portion of the bearing outer ring fails, and the relative movement of the ball joint pair squeezes the energy absorption layer.

[0016] In one or more embodiments of the fan blade mounting structure, when the rolling fit between the rolling element and the inner ring and outer ring of the bearing fails under the action of an impact load, the ball joint pair between the outer ring of the bearing and the inner wall of the hole of the hub allows the blade handle to rotate in the hole of the hub.

[0017] According to an installation method of the second aspect of the present invention, the fan blade is installed to the hub using the fan blade installation structure introduced above.

[0018] An open rotor engine according to the third aspect of the present invention comprises a fan blade mounting structure as described above, as well as fan blades and a hub, wherein the fan blade comprises a blade handle, and the blade handle is mounted to the hub via the fan blade mounting structure so that the fan blade is mounted and connected to the hub.

[0019] The improvement effect of this case is that it reduces the impact energy transmitted to the hub under large impact load and prevents blade jamming. Specifically, the improvement effect includes but is not limited to: 1. Reduce impact load: When the load exceeds the threshold, the outer ring of the bearing is decoupled from the fan hub, and the two are matched with each other through the energy-absorbing structure, and the impact energy is absorbed by the energy-absorbing layer, while reducing the load transmitted to the hub to ensure the safety of the hub.

[0020] 2. Anti-stuck: When the load exceeds the threshold, the ball joint surface allows the blade handle to rotate with the fan blade mounting structure and the fan hub, preventing the blade handle and the hub hole from getting stuck due to the failure of the rolling fit between the rolling element and the inner and outer rings of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments. It should be noted that the drawings are only examples and are not drawn to scale, and should not be used as a limitation on the actual scope of protection required by the present invention, wherein: Figure 1 It is a schematic structural diagram of an open rotor engine according to an embodiment.

[0022] Figure 2 It is a structural schematic diagram of a fan blade mounting structure of an embodiment.

[0023] Reference numerals: 100-Open Rotor Engine 10-Fan blade mounting structure 20-Fan blades 30-Wheel Hub 40-Petiole 50-Inner wall of the wheel hub hole 501-Second ball joint surface 1-Bearing device 11-Bearing inner ring 12-Rolling element 121- inclined cylindrical rolling element 122-Ball Roller 13-Bearing outer ring 131-upper section 132-Middle 1320-First ball joint surface 133-Next section 141-First mechanical weak point 142-Second mechanical weak point 15-Energy absorbing layer 2-Compression fittings. DETAILED DESCRIPTION

[0024] Reference will now be made in detail to the various embodiments of the application, the examples of which are shown in the accompanying drawings and are described below. Although the application will be described in conjunction with the exemplary embodiments, it should be appreciated that this specification is not intended to limit the application to those exemplary embodiments. On the contrary, the application is intended to not only cover these exemplary embodiments, but also to cover various alternative forms, modified forms, equivalent forms and other embodiments that may be included in the spirit and scope of the application defined by the appended claims.

[0025] In addition, it should be understood that, for example, "one embodiment", "an embodiment", and / or "some embodiments", "one or more embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "some embodiments" or "one or more embodiments" mentioned twice or more in different places in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of the present application may be appropriately combined.

[0026] In the description of the embodiments of the present application, the technical terms "first" and "second", such as the first paragraph, the second paragraph, etc., are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0027] In the following description, the directions or positional relationships indicated by "upstream", "downstream" or other directional terms are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present application. In addition, in the specification of the present application, "upstream", "downstream", "front" and "rear" are distinguished based on the general flow direction of air during engine operation, that is, during engine operation, air generally flows from "upstream" to "downstream" and from "front" to "rear", and this direction is also roughly the "intake" to "exhaust" direction of the engine turbine.

[0028] like Figure 1 As shown, in some embodiments, the open rotor engine 100 includes a fan blade mounting structure 10 , a fan blade 20 , a hub 30 , a variable pitch device 60 , an intake cone 70 , and the fan blade 20 includes a blade handle 40 .

[0029] The inlet cone 70 is generally located at the front end of the open rotor engine 100, and the fan blade 20 is adjacent to the inlet cone 70. The blade stalk 40 of the fan blade 20 is connected to the hub 30 through the fan blade mounting structure 10 which will be described in detail in the following embodiments; the end of the blade stalk 40 cooperates with the pitch device 60 to achieve the axial rotation of the blade stalk 40 under the drive of the pitch device 60 to adjust the pitch angle of the fan blade 20.

[0030] The fan blades 20 of the open rotor engine 100 are usually designed with a wide chord, thin blade shape and long span. The impact and unbalanced load generated when encountering unexpected situations such as bird strikes are transmitted from the stalk 40 to the hub 30 through the fan blade mounting structure 10, and further transmitted to the fulcrum and the load-bearing casing through the fan shaft 80.

[0031] refer to Figure 1 as well as Figure 2 As shown, the fan blade mounting structure 10 is coaxial with the blade handle 40 and can withstand the axial force (corresponding to the centrifugal force) and radial force (corresponding to the bending moment) from the fan blade 20 at the same time.

[0032] Continue to refer Figure 1 as well as Figure 2 As shown, in some embodiments, the fan blade mounting structure 10 includes: a bearing device 1, which includes radially from the inside to the outside: a bearing inner ring 11, a rolling body 12, and a bearing outer ring 13, and the rolling body 12 is rollingly connected to the bearing inner ring 11 and the bearing outer ring 13 at both ends.

[0033] The bearing inner ring 11 is used for interference fit with the petiole 40 .

[0034] The bearing outer ring 13 is used to connect with the inner wall 50 of the hole of the wheel hub; wherein the bearing outer ring 13 includes an upper section 131, a middle section 132 and a lower section 133 which are sequentially distributed along the axial direction, and the upper section 131 of the bearing outer ring cooperates with the clamping member 2, and the clamping member 2 can be, for example, the clamping nut shown in the figure, but is not limited thereto. The middle section 132 and the lower section 133 cooperate with the inner wall 50 of the hole of the wheel hub, and there is a first mechanical weak point 141 between the upper section 131 and the middle section 132 of the bearing outer ring, and there is a second mechanical weak point 142 in the lower section 133.

[0035] The specific structures of the first mechanical weak point 141 and the second mechanical weak point 142 are, for example, Figure 2 As shown, there may be an arc-shaped thinning section between the upper section 131 and the middle section 132, the thickness of which is thinner than the upper section 131 and the middle section 132, and the lower section 133 may have an arc-shaped thinning section that is thinner than the lower section 133, but this is not limited to it, and it may also be other shapes of thinning, or it may be in the form of a material that is thinner than the upper section 131, the middle section 132, and the lower section 133, which is not limited to this.

[0036] The middle section 132 has a first spherical joint surface 1320 , and the inner wall 50 of the hole of the wheel hub has a second spherical joint surface 501 . The first spherical joint surface 1320 and the second spherical joint surface 501 cooperate with each other to form a spherical joint pair, and an energy absorption layer 15 is arranged between the first spherical joint surface 1320 and the second spherical joint surface 501 .

[0037] The beneficial effect of adopting the above embodiment is to reduce the impact energy transmitted to the hub under large impact load and prevent the blade from getting stuck. Specifically, the beneficial effects include but are not limited to: it can reduce the impact load. When the load exceeds the threshold, the outer ring of the bearing is decoupled from the fan hub, and the two are matched by the energy-absorbing structure through the spherical joint surface, and the impact energy is absorbed by the energy-absorbing layer, while reducing the load transmitted to the hub to ensure the safety of the hub. In addition, it can also prevent jamming. When the load exceeds the threshold, the spherical joint surface allows the blade handle to rotate with the fan blade mounting structure and the fan hub, preventing the blade handle and the hub hole from getting stuck due to the failure of the rolling fit between the rolling body and the inner and outer rings of the bearing.

[0038] In some embodiments, the material of the energy absorbing layer 15 can be artificial cartilage foam (ACF), which is a typical soft matrix mixed cell material, and is also a three-dimensional ultra-microstructure bionic metamaterial designed based on the function and structure of human knee cartilage. There are micron-sized holes inside the material, and there is a certain degree of connectivity between the holes. There are gully-shaped protrusions distributed on the hole surface, and these heights are all at nanometer heights. The beneficial effect of this is that it can better achieve the effect of energy absorption.

[0039] In some embodiments, the specific structure of the rolling body 12 can be that the rolling body 12 includes an inclined cylindrical rolling body 121 and a spherical rolling body 122. The inclined cylindrical rolling body 121 and the spherical rolling body 122 are arranged axially to jointly support the petiole 40. The beneficial effect of this is that a more stable support effect can be provided.

[0040] In some embodiments, when the fan is in a normal state, the bearing outer ring 13 and the inner wall 50 of the hub hole are relatively fixed without relative sliding. The blade handle 40 can rotate relative to the hub 30 through the rolling body 12, that is, the relative rotation between the blade handle 40 and the hub hole required for the pitch angle adjustment of the fan blade 20 is achieved by the rolling body 12 in the fan blade mounting structure 10, ensuring the normal operation of the fan blade 20.

[0041] When the impact load transmitted from the fan blade 20 to the bearing outer ring 13 exceeds a threshold value, the first mechanical weak point 141 and / or the second mechanical weak point 142 of the bearing outer ring 13 fail, that is, at this time, the upper section 131 and the lower section 133 of the bearing outer ring 13 are disconnected from the inner wall 50 of the hole of the hub, and the bearing outer ring 13 is connected to the inner wall 50 of the hole of the hub through a ball joint pair formed by the inner wall 50 of the hole of the hub and the middle section 132, so that the bearing outer ring 13 and the inner wall 50 of the hole of the hub can rotate and tilt relative to each other, and at the same time can provide partial constraints to ensure that the petiole 40 does not fly out.

[0042] In addition, when the impact load transmitted from the fan blade 20 to the bearing outer ring 13 exceeds a threshold value, the first mechanical weak point 141 and / or the second mechanical weak point 142 of the bearing outer ring 13 fails, and the relative movement of the ball joint pair squeezes the energy absorption layer 15 to absorb the impact energy and reduce the load transmitted to the hub 30.

[0043] That is, the first mechanical weak point 141 and / or the second mechanical weak point 142 on the bearing outer ring 13 fails. On the one hand, the load transfer path from the petiole 40 to the hub 30 is reduced, and the relative movement of the ball joint pair squeezes the energy-absorbing layer 15 to absorb the impact energy, reduce the load transferred to the hub 30, and ensure the safety of the hub 30.

[0044] In addition, when the rolling fit between the rolling body 12 and the bearing inner ring 11 and the bearing outer ring 13 fails under the action of impact load, the ball joint pair between the bearing outer ring 13 and the inner wall 50 of the hole of the hub allows the blade handle 40 to rotate in the hole of the hub 30, that is, the ball joint pair allows the blade handle 40 to still rotate in the hub hole under the drive of the variable pitch device 60, so that the fan blade 20 can be adjusted to the appropriate pitch angle, ensuring the safety of the engine.

[0045] It can be understood that, as described above, the present application also provides an installation method, which uses the fan blade installation structure 10 described in the above embodiment to install the fan blade 20 to the hub 30.

[0046] In summary, the beneficial effects of the above embodiments are to reduce the impact energy transmitted to the hub under a large impact load and prevent the blade from getting stuck. Specifically, the beneficial effects include but are not limited to: 1. Reduce impact load: When the load exceeds the threshold, the outer ring of the bearing is decoupled from the fan hub, and the two are matched with each other through the energy-absorbing structure, and the impact energy is absorbed by the energy-absorbing layer, while reducing the load transmitted to the hub to ensure the safety of the hub.

[0047] 2. Anti-stuck: When the load exceeds the threshold, the ball joint surface allows the blade handle to rotate with the fan blade mounting structure and the fan hub, preventing the blade handle and the hub hole from getting stuck due to the failure of the rolling fit between the rolling element and the inner and outer rings of the bearing.

[0048] Although the present invention is disclosed as above with the above embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A fan blade mounting structure (10), characterized in that: Used to mount a fan blade (20) on a wheel hub (30), the fan blade (20) comprising a blade handle (40), the blade handle (40) being mounted on the wheel hub (30) via the fan blade mounting structure (10), the fan blade mounting structure (10) comprising: The bearing device (1) comprises, from the inside to the outside in a radial direction: a bearing inner ring (11), a rolling element (12), and a bearing outer ring (13), wherein the rolling element (12) is rollingly connected to the bearing inner ring (11) and the bearing outer ring (13) at two ends thereof; The bearing inner ring (11) is used for interference fit with the petiole (40); The bearing outer ring (13) is used to connect with the inner wall (50) of the hole of the wheel hub; The bearing outer ring (13) comprises an upper section (131), a middle section (132) and a lower section (133) which are sequentially distributed along the axial direction; the upper section (131) of the bearing outer ring cooperates with the pressing member (2); the middle section (132) and the lower section (133) cooperate with the inner wall (50) of the hole of the wheel hub; a first mechanical weak portion (141) is provided between the upper section (131) and the middle section (132) of the bearing outer ring; and the lower section (133) has a second mechanical weak portion (142); The middle section (132) has a first spherical joint surface (1320), and the inner wall (50) of the hole of the wheel hub has a second spherical joint surface (501). The first spherical joint surface (1320) and the second spherical joint surface (501) cooperate with each other to form a spherical joint pair, and an energy absorption layer (15) is provided between the first spherical joint surface (1320) and the second spherical joint surface (501).

2. The fan blade mounting structure (10) according to claim 1, characterized in that: The fan blade mounting structure (10) is coaxial with the blade handle (40) of the fan blade and can simultaneously withstand the axial force and radial force from the fan blade (20).

3. The fan blade mounting structure (10) according to claim 2, characterized in that: The rolling body (12) comprises an inclined cylindrical rolling body (121) and a ball rolling body (122); the inclined cylindrical rolling body (121) and the ball rolling body (122) are arranged along the axial direction and jointly support the petiole (40).

4. The fan blade mounting structure (10) according to claim 1, characterized in that: The energy absorbing layer (15) is made of artificial cartilage foam material.

5. The fan blade mounting structure (10) according to claim 1, characterized in that: When the fan is in a normal state, the bearing outer ring (13) and the inner wall (50) of the hole of the hub are relatively fixed, and the blade handle (40) can rotate relative to the hub (30) through the rolling body (12).

6. The fan blade mounting structure (10) according to claim 1, characterized in that: When the impact load transmitted from the fan blade (20) to the bearing outer ring (13) exceeds a threshold value, the first mechanical weak point (141) and / or the second mechanical weak point (142) of the bearing outer ring (13) fails, and the bearing outer ring (13) is now connected to the inner wall of the hole (50) of the wheel hub via a ball joint formed by the inner wall of the hole (50) of the wheel hub and the middle section (132), so that the bearing outer ring (13) and the inner wall of the hole (50) of the wheel hub can rotate and tilt relative to each other.

7. The fan blade mounting structure (10) according to claim 6, characterized in that: When the impact load transmitted from the fan blade (20) to the bearing outer ring (13) exceeds a threshold value, the first mechanical weak point (141) and / or the second mechanical weak point (142) of the bearing outer ring (13) fails, and the relative movement of the ball joint pair squeezes the energy absorption layer (15).

8. The fan blade mounting structure (10) according to claim 1, characterized in that: When the rolling fit between the rolling element (12) and the bearing inner ring (11) and the bearing outer ring (13) fails under the action of an impact load, the ball joint pair between the bearing outer ring (13) and the inner wall (50) of the hole of the wheel hub allows the blade handle (40) to rotate in the hole of the wheel hub (30).

9. An installation method, characterized in that: The fan blade (20) is mounted on the hub (30) using the fan blade mounting structure (10) according to any one of claims 1 to 8.

10. An open rotor engine (100), characterized in that: The fan blade mounting structure (10) comprises a fan blade (20) and a hub (30), wherein the fan blade (20) comprises a blade stalk (40), and the blade stalk (40) is mounted on the hub (30) through the fan blade mounting structure (10), so that the fan blade (20) is mounted and connected to the hub (30).

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