Power divider shaft protective cover mounting structure with damping function for aero-engine

Abstract

The invention relates to an aero-engine power divider shaft protective cover mounting structure with a damping function, which comprises a split protective cover, and a hoop is sleeved on the split protective cover; the hoop comprises a holding ring, the two ends of the holding ring are tightly attached connecting plates, and connecting through holes are formed in the connecting plates. The middle part of the holding ring is an annular plate; a metal rubber bushing ring is attached to the inner side of the annular plate; the hoops are screwed through screws and nuts to fix the split type protective cover, the embracing ring and the metal rubber lining ring are completed through the spot welding technology, spot welding positions are evenly distributed between the embracing ring and the metal rubber lining ring, and the hoops are arranged on the split type protective cover in a sleeved mode and located at the front end, the middle end and the rear end of the split type protective cover. According to the invention, by utilizing the vibration reduction characteristic of the metal rubber, the vibration reduction requirement of the installation and fixation of the existing aviation FDJ power divider shaft protection cover is realized; the metal wires in the metal rubber bushing ring are directly made of stainless steel materials, do not need special treatment to meet the requirements of the use environment, and are fixed on the original hoop through spot welding.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation engine accessories and relates to an aviation engine power take-off shaft protective cover installation structure with a shock absorbing function. Background Art

[0002] In addition to providing thrust for the aircraft, aircraft engines also need to provide power to the aircraft through a power take-off shaft device for use by aircraft accessories. In some usage scenarios, in order to allow the aircraft to obtain more power from the engine in advance and arrange more accessories, an additional aircraft accessory gearbox will be designed. The engine accessory gearbox is connected to the aircraft accessory gearbox through a power take-off shaft. During operation, the power take-off shaft is a high-speed rotating rotor. In order to prevent the high-speed speed from being damaged by pipelines or other surrounding objects during the operation process, a protective cover is generally designed outside the power take-off shaft.

[0003] Since aircraft and aero engines have strict requirements on important parts and compact space requirements, the protective cover is generally made of thin-walled shell sheet metal, which is stamped from cold-rolled plates and spot welded. It has the advantage of light weight and is installed on the aircraft accessory gearbox and engine accessory gearbox with a clamp. The traditional clamp is an open metal ring, which is tightened by screws and nuts to clamp the connection part to complete the installation and fixation of the protective cover.

[0004] Since the vibration energy generated by the engine covers a wide frequency band of 10-2000Hz, and the protective cover is a thin-walled sheet metal part, when it vibrates under the large vibration environment of the engine, the thin-walled sheet metal parts and spot welds are prone to vibration fatigue cracking. How to reduce vibration is a difficult problem in the installation and fixation of the protective cover.

[0005] In order to achieve the installation and fixation of the protective cover to reduce vibration, a technical solution is to use rubber to introduce damping between the clamp and the protective cover to reduce vibration. However, the problem of rubber aging is dealt with during use, and the temperature in the operating environment of the aircraft engine is between -55°C and about 200°C, and general rubber does not meet the operating environment. Summary of the invention

[0006] The purpose of the present invention is to provide a power take-off shaft protective cover installation structure for an aircraft engine with a shock absorbing function, which can solve the problem that when the protective cover, as a thin-walled sheet metal part, vibrates in a large vibration environment of the engine, the thin-walled sheet metal parts and spot welds are prone to vibration fatigue cracking.

[0007] According to the technical solution provided by the present invention: a power take-off shaft protective cover installation structure for an aircraft engine with a shock-absorbing function includes a split protective cover, on which a clamp is sleeved; the clamp includes a clamp ring, and the two ends of the clamp ring are tightly connected plates, and the connecting plate is provided with a connecting through hole; the middle part of the clamp ring is a ring plate, and the inner side of the ring plate is covered with a metal rubber lining ring; the clamp is tightened and fixed to the split protective cover by screws and nuts.

[0008] As a further improvement of the present invention, the holding ring and the metal rubber liner ring are completed by a spot welding process, and the spot welding positions are evenly distributed between the holding ring and the metal rubber liner ring.

[0009] As a further improvement of the present invention, a clamp is sleeved on the split protective cover and is located at the front, middle and rear ends of the split protective cover.

[0010] As a further improvement of the present invention, the split protective cover is composed of a first protective half shell and a second protective half shell; a positioning member is provided between the two; the positioning member is a side plate, which is evenly distributed on both sides of the first protective half shell and extends out of the first protective half shell.

[0011] As a further improvement of the present invention, heat dissipation holes are provided on the first protective half shell and the second protective half shell.

[0012] As a further improvement of the present invention, the first protective half shell and the second protective half shell are made of a thin-walled plate with a thickness between 0.2 mm and 0.8 mm by stamping.

[0013] As a further improvement of the present invention, the metal wire in the metal rubber liner ring is made of stainless steel.

[0014] The positive effects of this application are: 1. The present invention utilizes the vibration reduction characteristics of metal rubber to achieve the vibration reduction requirements of the existing aviation FDJ power take-off shaft protection cover installation and fixation.

[0015] The metal wire in the metal rubber liner ring of the present invention is directly made of stainless steel material, does not need special treatment to meet the requirements of the use environment, and is fixed on the original clamp by spot welding.

[0016] 3. The present invention can adjust the mechanical performance parameters of the metal wire gasket mesh element by adjusting the spiral warp and wire diameter of the metal wire and adjusting the density and thickness of the metal wire gasket mesh element according to the vibration isolation requirements of different types of protective covers, and has strong universality and engineering applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure 2 It is a schematic diagram of the decomposition of the present invention.

[0019] Figure 3 It is a schematic structural diagram of the split protection cover of the present invention. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, similar terms such as "including" and "having" mean that in addition to those contents already listed in "including" and "having", other contents that have not been listed may also be "included" and "having"; for example, a process, method, system, product or device that may include a series of steps or units is not necessarily limited to those steps or units that have been clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] Due to the angle of the drawing, some components may not be drawn, but their positions and connection relationships can be partially understood based on the text expression.

[0024] like Figure 1 As shown, the present invention is a power take-off shaft protective cover installation structure for an aircraft engine with a shock absorbing function, comprising a split protective cover 9, on which a clamp 4 is sleeved.

[0025] The hoop 4 includes a ring 1, and the two ends of the ring 1 are tightly connected plates, and the connecting plates are provided with connecting through holes for passing bolts. The middle part of the ring 1 is a ring plate, which is used to clamp the split protective cover 9. The inner side of the ring plate is covered with a metal rubber liner ring 2, and the metal rubber liner ring 2 is made of metal rubber. The ring 1 and the metal rubber liner ring 2 are completed by a spot welding process, and the spot welding positions 3 are evenly distributed between the ring 1 and the metal rubber liner ring 2. The metal rubber liner ring 2 performs vibration isolation and vibration reduction and energy absorption.

[0026] Metal rubber is a porous, functional and efficient damping material, which is made of metal wire through the processes of wire selection, wire winding, stretching, weaving and molding. Its special molding process gives it many excellent properties: 1) High elasticity. Through the optimized design of metal rubber components, its elastic modulus can be changed within the range of 104~109Pa, that is, the stiffness is adjustable.

[0027] 2) High damping. The loss factor can generally reach 0.2~0.5 (0.06 for general steel springs and 0.22~0.47 for natural rubber), and it has good absorption capacity for transient impact loads.

[0028] 3) High sound absorption coefficient. Its sound absorption coefficient can reach α=0.6~1.0, which is a highly efficient sound absorption material, and its porosity is controllable, that is, the sound absorption performance can be designed.

[0029] 4) Low thermal conductivity. The thermal conductivity of metal rubber is much lower than that of metal wire, generally 1%~2% of the thermal conductivity of metal wire material.

[0030] 5) Low expansion coefficient. The volume expansion coefficient of metal rubber is 30% of the volume expansion coefficient of its metal wire.

[0031] 6) Low weight. Its density is less than 0.3 of the wire material.

[0032] 7) Strong environmental adaptability. It does not evaporate in the space environment, is not afraid of space radiation and particle impact, is resistant to high and low temperatures, corrosion, and is not easy to age, and can be stored for a long time.

[0033] 8) Strong plasticity. It can be made into various complex shapes according to the characteristics of the installation space.

[0034] The metal rubber exhibits nonlinear stiffness-damping characteristics. As the vibration energy increases, the compression of the metal rubber increases, and the stiffness-damping improves, thereby effectively dissipating and isolating the vibration energy. The performance parameters of the metal rubber liner 2 can be adjusted by adjusting the spiral diameter and wire diameter of the metal wire and adjusting the density and thickness of the metal rubber liner 2.

[0035] The metal wire in the metal rubber liner ring 2 is directly made of stainless steel without special processing to meet the requirements of the use environment, and is fixed to the original clamp by spot welding, so the structure is simple.

[0036] Three clamps 4 are sleeved on the split protective cover 9, located at the front, middle and rear ends of the split protective cover 9. The front and rear ends of the split protective cover 9 are provided with mounting rings for matching the clamps 4. The clamps 4 are tightened and fixed to the split protective cover 9 by screws 7 and nuts 8.

[0037] The split protective cover 9 is composed of a first protective half shell 5 and a second protective half shell 6, and a positioning member is arranged between the two. The positioning member is a side plate 10, which is evenly distributed on both sides of the first protective half shell 5. The side plates 10 extend outward from the first protective half shell 5 to position the second protective half shell 6, so as to facilitate the assembly of the two.

[0038] The first protective half shell 5 and the second protective half shell 6 are formed by stamping and spot welding thin-walled plates with a thickness between 0.2 mm and 0.8 mm, and have the advantage of being light in weight. The first protective half shell 5 and the second protective half shell 6 are both provided with heat dissipation holes.

[0039] When vibration is transmitted from the engine to the split protective cover 9, on the one hand, the rigidity of the metal rubber lining ring 2 is relatively small, and compared with the structure without the metal rubber lining ring 2, the rigidity of the installation contact surface is reduced, which is conducive to vibration isolation; on the other hand, the metal rubber lining ring 2 is compressed during the process, and the friction between the metal wires in the metal rubber lining ring 2 provides damping energy dissipation. The friction of the contact interface between the metal rubber lining ring 2 and the holding ring 1 can also provide damping energy dissipation.

[0040] By adjusting the tightening torque of the bolt 7, different pre-compression amounts can be applied to the metal rubber liner ring 2 to ensure the stability of the mechanical properties of the metal rubber liner ring 2 during use.

[0041] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A power take-off shaft protective cover installation structure for an aircraft engine with a shock absorbing function, comprising a split protective cover (9), wherein a clamp (4) is sleeved on the split protective cover (9); the feature is that: The hoop (4) comprises a hoop (1), the two ends of the hoop (1) are tightly attached connecting plates, and the connecting plates are provided with connecting through holes; the middle part of the hoop (1) is a ring plate, and the inner side of the ring plate is covered with a metal rubber lining ring (2); the hoop (4) is tightened and fixed with a split protective cover (9) by means of screws (7) and nuts (8).

2. The mounting structure of the power take-off shaft protective cover for an aircraft engine with a shock absorbing function as claimed in claim 1, characterized in that: The holding ring (1) and the metal rubber lining ring (2) are completed by a spot welding process, and the spot welding positions (3) are evenly distributed between the holding ring (1) and the metal rubber lining ring (2).

3. The mounting structure of the power take-off shaft protective cover with a shock absorbing function for an aircraft engine according to claim 1, characterized in that: Three holding hoops (4) are sleeved on the split protective cover (9) and are located at the front, middle and rear ends of the split protective cover (9).

4. The power take-off shaft protective cover installation structure with a shock absorbing function for an aircraft engine according to claim 1, characterized in that: The split protection cover (9) is composed of a first protection half shell (5) and a second protection half shell (6); a positioning member is provided between the two; the positioning member is a side plate (10), the side plates (10) are evenly distributed on both sides of the first protection half shell (5), and the outer side of the side plates (10) extends out of the first protection half shell (5).

5. The mounting structure of the power take-off shaft protective cover with a shock absorbing function for an aircraft engine according to claim 1, characterized in that: The first protective half shell (5) and the second protective half shell (6) are both provided with heat dissipation holes.

6. The mounting structure of the power take-off shaft protective cover for an aircraft engine with a shock absorbing function as claimed in claim 1, characterized in that: The first protective half shell (5) and the second protective half shell (6) are made of a thin-walled plate with a thickness between 0.2 mm and 0.8 mm by stamping.

7. The power take-off shaft protective cover installation structure with a shock absorbing function for an aircraft engine according to claim 1, characterized in that: The metal wire in the metal rubber lining ring (2) is made of stainless steel.

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