Double-plane engine damping device

Abstract

The invention provides a double-plane engine damping device, and relates to the field of power device damping, the device comprises a front-row damper and a rear-row damper, the front-row damper is detachably fixed on a main mounting casing of an engine, close to the mass center of the engine and used for bearing thrust and torque load of the engine, and the rear-row damper is detachably fixed on the main mounting casing of the engine. The front-row shock absorbers fixed with the lower part of the engine are vertically arranged, so that the engine can be directly hoisted for installation; the rear-row shock absorber is fixed to an auxiliary installation casing of the engine, structurally releases the degree of freedom of the rear-row shock absorber in the thrust direction and is used for balancing the deformation posture of the engine and remarkably restraining relative deformation in the pitching posture. The double-plane engine vibration reduction device can effectively cope with multi-dimensional complex vibration such as axial thrust and pitching moment of an engine, and the overall vibration reduction efficiency and the system operation stability are remarkably improved. And part of the front-row shock absorbers are vertically arranged, so that butt joint installation of the engine and the aircraft pylon can be completed by directly hoisting the engine, and the installation process is simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aeronautical vibration reduction technology, and in particular to a double-plane engine vibration reduction device. BACKGROUND

[0002] The aero-engine is one of the main vibration sources of various aircraft pylons. The engine vibration is transmitted to the aircraft body through the vibration reducer, causing cabin noise and body vibration, resulting in damage to some airborne equipment and affecting flight safety. The vibration of the turboprop engine mainly comes from the rotation of the propeller (the first-order excitation frequency is about 70 Hz). This frequency is easily coupled with the natural frequency of the engine nacelle and the fuselage, resulting in the risk of structural resonance. At the same time, during the engine starting / stop process, the gear box and transmission system will produce instantaneous impact vibration due to the large change rate of the rotation speed, which seriously affects the service life of the engine and the comfort of flight.

[0003] Therefore, it is necessary to provide a vibration reduction device in the prior art to reduce the transmission of engine vibration to the aircraft body.

[0004] The applicant finds that the prior art at least has the following technical problems: the vibration reduction device in the prior art only has a certain vibration reduction effect in a single direction, and its vibration reduction capacity is relatively limited for complex multi-directional vibration. The vibration reduction device in the prior art can only consume vibration energy through a single path, and may not effectively absorb some high-frequency or large-amplitude vibrations, resulting in poor vibration reduction effect. SUMMARY

[0005] The present application aims to provide a double-plane engine vibration reduction device to solve the technical problem that the vibration reduction device in the prior art is difficult to reduce complex multi-directional vibration and has poor vibration reduction effect. The preferred technical solutions in the technical solutions provided by the present application can produce the technical effects described below.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions: The double-plane engine vibration reduction device provided by the present application comprises a front row of vibration reducers and a rear row of vibration reducers for fixedly connecting the engine and the aircraft pylon, wherein: The front row of vibration reducers is used to bear the thrust and torque load of the engine, and all the front row of vibration reducers are detachably fixed to the main mounting case of the engine and located near the center of mass of the engine, wherein the front row of vibration reducers fixed to the lower part of the engine are vertically arranged, thereby facilitating direct hoisting of the engine for installation; The rear row of vibration reducers is fixed to the auxiliary mounting case of the engine, and is released in the thrust direction on the structure to balance the deformation attitude of the engine and significantly suppress the relative deformation in the pitch attitude.

[0007] Preferably, all the front shock absorbers are arranged in a spaced manner on the main mounting brake of the engine, and are arranged in an inclined manner compared with the vertical line relative to the front shock absorbers fixed on the upper half of the engine. The number of the rear shock absorbers is one or two, and when the number of the rear shock absorbers is two, the rear shock absorbers are arranged in a symmetrical manner on the axis of the engine or in a symmetrical manner on the left and right sides.

[0008] Preferably, the front shock absorber comprises a bracket and a first rubber assembly, wherein: The bracket is used for detachable fixed connection with the engine, the first rubber assembly is fixed on the front side and / or the rear side of the bracket, a front locking member passes through the bracket and all the first rubber assemblies, and is used for fixed connection of the front shock absorber and the aircraft hanger, the center of the front shock absorber is arranged in an eccentric manner compared with the center of the front locking member, and is used for resisting the counter torque generated by the propeller rotation on the engine.

[0009] Preferably, the front shock absorber further comprises a limiting sleeve, the limiting sleeve passes through the first rubber assembly and the bracket, the bracket is provided with a limiting groove, the limiting sleeve extends into the limiting groove, the front locking member passes through the limiting sleeve to fixedly connect the front shock absorber and the aircraft hanger, and the limiting sleeve cooperates with the inner wall of the limiting groove, and is used for limiting the displacement amount of the front shock absorber.

[0010] Preferably, the first rubber assembly comprises a front supporting plate, an elastic rubber plate and a rear cover plate, wherein: The front supporting plate and the rear cover plate clampingly fix the elastic rubber plate, and the three are integrally formed by vulcanization.

[0011] Preferably, the bracket comprises an integrally formed base and a supporting plate, wherein: The base is arranged in a vertical manner with the supporting plate, and the base is provided with a hole position for fixed connection with the engine; The supporting plate and / or the base is provided with a lightening hole, the first rubber assembly is fixed on the front and rear sides of the supporting plate, a first gasket is clampingly fixed between the first rubber assembly and the supporting plate, a second gasket is installed on the bottom of the base, and a reinforcing rib is arranged between the supporting plate and the base.

[0012] Preferably, one of the bracket and the first rubber assembly is provided with a positioning hole, and the other is provided with a positioning column, the number of the positioning holes is at least two and the sizes of the positioning holes are different, the number of the positioning columns is at least two and the sizes of the positioning columns are different, the positioning hole is inserted and matched with the positioning column of the corresponding size, so as to ensure accurate installation of the first rubber assembly and the bracket. The bottom of the support is provided with a protruding shear positioning column groove for positioning with the engine.

[0013] Preferably, the rear row damper comprises a support frame and a second rubber assembly, wherein: The support frame has a first connecting end and a second connecting end, and a rear row locking member passes through the first connecting end and the support frame, so as to detachably and fixedly connect the rear row damper with the aircraft pylon. The number of the second connecting end is one or more than two, for detachable and fixed connection with the engine.

[0014] Preferably, the support frame comprises a tripod and an end frame, wherein: The second connecting end is located at the two bottom ends of the tripod, and the first connecting end is located at the top of the end frame, and the end frame is provided with fixed holes and mounting grooves arranged at intervals, and the rear row locking member passes through the fixed holes to fixedly connect or rotatably connect the end frame with the aircraft pylon, so as to release the rear row damper in structure from the freedom degree in the thrust direction.

[0015] The other end of the tripod extends into the mounting groove and is rotatably connected with the end frame, and the second rubber assembly is located on one side or opposite sides of the mounting groove, and a fixing member passes through the mounting groove and the second rubber assembly to fix the second rubber assembly at the mounting groove.

[0016] Preferably, the fixing member is sleeved with a T-shaped limiting cylinder, the cylinder body of the T-shaped limiting cylinder passes through the second rubber assembly, and the end of the T-shaped limiting cylinder abuts against the outside of the second rubber assembly. The support frame is provided with a weight-reducing hollow area.

[0017] The double-plane engine damper provided by the application has the following beneficial effects compared with the prior art: the front row damper and the rear row damper are arranged at the front end and the rear end of the engine, and are endowed with different stiffness characteristics, the front row damper is used to bear the thrust and torque load of the engine, the rear row damper is fixed to the auxiliary mounting case of the engine, is released in structure from the freedom degree in the thrust direction, is used to balance the deformation posture of the engine and significantly suppresses the relative deformation in the pitching posture, realizes the division of function and the cooperative matching, can simultaneously and effectively cope with the multi-dimensional complex vibration of the axial thrust, the pitching torque and the like of the engine, significantly improves the overall damping efficiency and the system operation stability. At the same time, the vertical arrangement of part of the front row damper realizes the direct hoisting of the engine to complete the docking installation with the aircraft pylon, greatly simplifies the installation process, shortens the assembly and maintenance time, ensures the operation stability, the installation accuracy and the structural integrity of the device in the harsh aviation environment, and improves the overall reliability and safety. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the accompanying drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained based on these drawings without creative labor.

[0019] Figure 1 Fig. 1 is a schematic diagram of the overall structure of a double-plane engine damping device; Figure 2 Fig. 2 is a schematic diagram of the structure assuming that all front-row dampers are arranged around the axis of the engine; Figure 3 Fig. 3 is a schematic diagram of the arrangement of the front-row dampers in the present embodiment; Figure 4 Fig. 4 is a schematic diagram of the overall structure of the front-row dampers; Figure 5 Fig. 5 is a schematic diagram of the exploded structure of the front-row dampers; Figure 6 Fig. 6 is a schematic diagram of the arrangement of the front-row dampers and front-row locking members; Figure 7 Fig. 7 is a schematic diagram of the cross-sectional structure of the front-row dampers; Figure 8 Fig. 8 is a schematic diagram of the cooperation structure of the limiting sleeve and the limiting groove; Figure 9 Fig. 9 is a schematic diagram of the structure of the bracket in the front-row dampers; Figure 10 Fig. 10 is a schematic diagram of the structure of the rear cover plate; Figure 11 Fig. 11 is a schematic diagram of the structure of the rear-row dampers; Figure 12 Fig. 12 is a schematic diagram of the cross-sectional structure of the rear-row dampers; Figure 13 Fig. 13 is a schematic diagram of the structure of the tripod; Figure 14 Fig. 14 is a schematic diagram of the structure of the end bracket; Figure 15 Fig. 15 is a curve of the relationship between the transmission rate and the frequency.

[0020] 100, front row shock absorber; 1, support; 10, reinforcing rib; 11, base; 111, hole site; 12, support plate; 121, positioning column; 13, lightening hole; 14, shear-resistant positioning column groove; 2, first rubber assembly; 21, front support plate; 22, elastic rubber plate; 23, rear cover plate; 231, positioning hole; 24, limiting groove; 3, front row locking piece; 4, limiting sleeve; 5, first gasket; 6, second gasket; 200, rear row shock absorber; 7, support frame; 701, first connecting end; 702, second connecting end; 71, tripod; 72, end frame; 721, fixing hole; 722, mounting groove; 73, lightening hollow area; 8, second rubber assembly; 91, rear row locking piece; 92, fixing piece; 93, T-shaped limiting cylinder; 94, bearing. DETAILED DESCRIPTION

[0021] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0022] In the description of the present application, it should be understood that the terms "center", "length", "width", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "side" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0023] The embodiment of the present application provides a double-plane engine shock absorber device, which is used for connecting an engine to an aircraft pylon, in particular, to a special load-bearing structure on the aircraft pylon, such as an aircraft pylon 300. In an embodiment of the present application, the device adopts a double-plane layout to realize decoupling processing and isolation of complex loads of the engine.

[0024] The technical solutions provided by the present application will be described in more detail below. Figures 1-15 The technical solutions provided by the present application will be described in more detail below.

[0025] As Figures 1-14As shown, the double-plane engine vibration damping device provided by the present application comprises front row dampers 100 and rear row dampers 200 for fixedly connecting the engine and the aircraft pylon 300, wherein: the front row dampers 100 are used to bear the thrust and torque load of the engine, all the front row dampers 100 are detachably fixed to the main mounting nacelle of the engine, specifically located at the front end of the engine and close to the mass center position of the engine, and the front row dampers 100 fixed to the lower part of the engine are vertically arranged, thereby facilitating the direct hoisting of the engine; the rear row dampers 200 are fixed to the auxiliary mounting nacelle of the engine, specifically located at the rear end of the engine, and are structurally released in the thrust direction freedom, used to balance the deformation posture of the engine and significantly suppress the relative deformation in the pitch posture.

[0026] As shown in Figure 1 As shown, the front row dampers 100 are arranged near the overall mass center of the engine, which is conducive to effectively isolating vibration and reducing additional torque generated by vibration. The front row dampers 100, as the main bearing structure, bear the axial thrust generated when the engine is working, such as Figure 1 As shown, the front row dampers 100 mainly bear the force in the X-axis direction (the thrust direction of the engine) and the torque load of the engine.

[0027] As shown in Figure 1 As shown, the rear row dampers 200 are arranged at a position away from the mass center of the engine, usually at the rear end of the engine. The rear row damping assembly mainly provides a restoring torque, is structurally released in the thrust direction freedom, is used to balance the deformation posture of the engine and significantly suppresses the relative deformation in the pitch posture, suppresses the pitch moment generated by the engine under the influence of factors such as thrust change and aerodynamic interference, and thereby maintains the posture stability of the engine. As shown in Figure 1 As shown, the rear row dampers 200 mainly damp in the Y-axis direction and the Z-axis direction.

[0028] Through such an axial double-plane layout and functional rigidity characteristic configuration, the front row dampers 100 and the rear row dampers 200 form a cooperative working relationship: the former mainly bears the thrust, isolates the high-frequency vibration near the mass center, and also considers resisting the torque; the latter mainly controls the posture and suppresses the pitch. It can be understood that, compared with the traditional single-plane damping system, this structure is helpful to more comprehensively cope with the multi-dimensional and coupled complex load specific to the turboprop engine, and the double-plane damping device can more effectively reduce the influence of engine vibration on the surrounding components.

[0029] As an optional implementation, as shown in Figure 1 and Figure 3As shown, all front shock absorbers 100 are arranged at intervals on the main mounting brake of the engine, and are inclined relative to the vertical line compared with the front shock absorbers 100 fixed to the upper part of the engine; the number of rear shock absorbers 200 is one or two. When the number of rear shock absorbers 200 is two, the rear shock absorbers 200 are arranged symmetrically about the engine axis, either vertically or horizontally.

[0030] See Figure 3 As shown in the figure, this illustrates the mounting method of the front shock absorber 100. As an optional implementation, the number of front shock absorbers 100 can be multiple (e.g., 3 to 4), see [link to relevant documentation]. Figure 3 As shown, the front shock absorber 100, which is fixed to the lower half of the engine, is vertically installed. When installing the engine and the aircraft pylon, the engine can be lifted directly from the bottom up, which is convenient for installation and the aircraft pylon structure is simple.

[0031] See Figure 2 As shown, assuming the front shock absorber 100 is set around the engine axis, that is, the front shock absorber 100 is set at an angle relative to the vertical line. During installation, since the two lower points are installed at an angle, the engine cannot be lifted directly. It is necessary to install the upper part of the aircraft rack first. After the engine is lifted, the lower part of the aircraft rack is installed with the upper part of the aircraft rack before fixing the front shock absorber 100. The structure is complex and the on-site installation is very cumbersome.

[0032] The layout of the front shock absorber 100 in this embodiment helps to simplify the installation process, reduce the need for complex alignment and multi-axial attitude adjustment, thereby shortening the assembly time and improving maintenance convenience.

[0033] Specifically, this dual-plane engine vibration damping device requires precise distribution of three-dimensional stiffness through geometric design. For example, the front damper can increase the x-axis stiffness by increasing the rubber bearing area, while the rear damper can optimize the y and z-axis flexibility through shear deformation design.

[0034] The following provides a specific implementation of the front shock absorber 100: See [link] Figures 4-7 As shown, the front shock absorber 100 includes a bracket 1 and a first rubber assembly 2, wherein: the bracket 1 is used for detachable fixed connection with the engine, the first rubber assembly 2 is fixed to the front and / or rear side of the bracket 1, and a front locking member 3 passes through the bracket 1 and all the first rubber assemblies 2 for fixed connection of the front shock absorber 100 and the aircraft rack.

[0035] Furthermore, to address the counter-torque unique to turboprop engines generated by propeller rotation, an eccentric design can be employed in the front shock absorber 100 in this embodiment. See also Figure 6, the center of the front shock absorber 100 is eccentrically arranged compared to the center of the front locking member 3, for resisting the counter torque generated by the propeller rotation to the engine.

[0036] As shown in Figure 6 , the purpose of the above structure is to resist the counter torque generated by the propeller rotation to the engine. The eccentric design can be understood as that the elastic center C1 of the first rubber assembly 2 (i.e. the center of symmetry of its geometry and elastic properties in the state of no force) has a preset offset distance relative to the center C2 of the locking member connected with the aircraft pylon (usually the axis center of the front locking member 3, such as the long bolt, passing through the entire front shock absorber 100). When the propeller rotates, the engine generates a counter torque, and the entire front shock absorber 100 will rotate slightly around the center C2 of the front locking member 3. Due to the offset of the elastic center C1, the first rubber assembly 2 will generate a restoring torque at this time, thereby effectively absorbing and balancing the counter torque and preventing it from being transmitted to the aircraft structure. After deflection, the center of the front shock absorber 100 coincides with the center of the front locking member 3. The structure integrates the anti-torque function into the shock absorber itself, and the structure is compact.

[0037] Wherein, the bracket 1 can be made of high-strength alloy material (such as titanium alloy or high-strength steel), and its shape can be optimized according to the installation position, for example, designed as T-shaped.

[0038] As an optional embodiment, as shown in Figure 4 , Figure 5 and Figure 7 , Figure 9 , the bracket 1 includes an integrally formed base 11 and a support plate 12, wherein: the base 11 is vertically arranged with the support plate 12, and the base 11 is provided with a hole site 111 for fixed connection with the engine; the support plate 12 and / or the base 11 is provided with a weight-reducing hole 13, the first rubber assembly 2 is fixed on the front and rear sides of the support plate 12, and a reinforcing rib 10 is arranged between the support plate 12 and the base 11.

[0039] Considering the high-temperature environment during engine operation, the embodiments of the present application further include a heat protection structure. As shown in Figure 5 , a first gasket 5 is clamped and fixed between the first rubber assembly 2 and the support plate 12, and a second gasket 6 is installed at the bottom of the base 11. The first gasket 5 and the second gasket 6 can be heat insulation pads, which are usually made of materials with extremely low thermal conductivity, such as mica sheets or ceramic fiber composite materials. In this embodiment, mica material with a thermal conductivity lower than 0.1 watt / meter·kelvin can be optionally used. By arranging a heat insulation pad with a thickness not exceeding 2 millimeters after compression, the surface temperature near the engine case, which can be as high as 400℃, can be effectively isolated, ensuring that the working temperature of the first rubber assembly 2 is maintained within its allowable range (for example, lower than 130℃), thereby ensuring its performance and service life.

[0040] The base 11 is fixed to the engine, for example, by high-strength bolts (e.g., 4 bolts) passing through the hole positions 111.

[0041] To ensure safety in extreme cases, a through-limiting structure is arranged inside the damper. As an optional embodiment, see Figure 8 As shown, the front damper 100 further comprises a limiting sleeve 4, which passes through the first rubber assembly 2 and the bracket 1, and the bracket 1 (specifically, the support plate 12) is provided with a limiting groove 24, the limiting sleeve 4 extends into the limiting groove 24, the front locking member 3 passes through the limiting sleeve 4 to fixedly connect the front damper 100 and the aircraft pylon, and the limiting sleeve 4 cooperates with the inner wall of the limiting groove 24 to limit the displacement of the front damper 100.

[0042] As shown, the limiting sleeve 4 passes through the central hole of the support plate 12 and the first rubber assembly 2, and the front locking member 3 passes through the limiting sleeve 4 and is locked with the aircraft pylon. In normal operation, the front damper 100 is elastically deformed, and the limiting sleeve 4 is not in contact with the limiting groove 24. However, if an accident occurs, the displacement of the engine will be limited by the limiting sleeve 4 and the limiting groove 24, and the bracket 1 will directly come into rigid contact with the limiting sleeve 4 or the front locking member 3, thereby maintaining the mechanical connection between the engine and the aircraft pylon and preventing the engine from moving too much to provide the final failure protection. Figure 8 The structure of the embodiment has a failure prevention function: the high-strength front locking member 3 passes through the first rubber assembly 2 and the limiting sleeve 4 to realize the connection with the aircraft pylon. It is ensured that the engine and the aircraft pylon will not be separated. Under the pre-tightening force of the front locking member 3, the two front support plates 21 + the limiting sleeve 4 + the bracket 1 are rigidly attached together, which can ensure the effective connection between the engine and the aircraft, and even in the case of complete damage or burning of the first rubber assembly 2, the engine and the aircraft pylon can be prevented from falling off and safety problems can be avoided.

[0043] As an optional embodiment, see

[0044] and Figure 5 As shown, the first rubber assembly 2 comprises a front support plate 21, an elastic rubber plate 22, and a rear cover plate 23, wherein: the front support plate 21 and the rear cover plate 23 clampingly fix the elastic rubber plate 22, and the three are a vulcanized one-piece structure. Figure 7 The front support plate 21 can be a metal material, mainly to bear various loads acting on the front damper 100, especially the heading load; the elastic rubber plate 22 is used to absorb the vibration generated by the engine and its matched propeller, and prevent the mutual transmission of the vibration between the fuselage and the engine; the rear cover plate 23 and the elastic rubber plate 22 together: play a limiting role.

[0045] ​

[0046] The first rubber assembly 2 is used to realize the damping function. In an embodiment of the present application, the front support plate 21, the elastic rubber plate 22 and the rear cover plate 23 are integrally formed by a high-temperature and high-pressure vulcanization process to ensure that the rubber has high bonding strength and reliability with the metal parts. It should be noted that the rubber material can be selected from silicon rubber or fluorine rubber which has high damping, high temperature resistance (for example, can work in an environment above 130°C for a long time) and excellent anti-aging performance.

[0047] At least one layer of spacers is added in the elastic rubber plate 22 between the front support plate 21 and the rear cover plate 23, which can effectively improve the carrying capacity and the service life of the first rubber assembly 2.

[0048] The geometry of the first rubber assembly 2 is also specially designed, for example, a rectangular cross-section is adopted, which can provide a larger force bearing area in a limited radial space compared to a circular cross-section, increase the axial and radial area of the first rubber assembly 2, increase the compression stiffness and shear stiffness, and thus achieve the required stiffness characteristics in different directions.

[0049] To improve the assembly accuracy and prevent incorrect installation, an error-proof assembly structure can also be provided between the first rubber assembly 2 of the front shock absorber 100 and the bracket 1. As an optional embodiment, one of the bracket 1 and the first rubber assembly 2 is provided with a positioning hole 231, and the other is provided with a positioning column 121, as shown in Figure 9 and Figure 10 In this embodiment, the bracket 1 is provided with the positioning column 121, and the rear cover plate 23 is provided with the positioning hole 231, the number of the positioning hole 231 is at least two and the sizes are different, the number of the positioning column 121 is at least two and the sizes are different, and the positioning hole 231 and the positioning column 121 of the corresponding size are inserted and matched, so as to ensure that the first rubber assembly 2 and the bracket 1 are accurately installed.

[0050] As shown in Figure 9 and Figure 10 Since the size and shape combination of the positioning column 121 and the positioning hole 231 is unique, the bracket 1 and the first rubber assembly 2 can only be assembled in the preset correct relative position and direction, so as to effectively avoid incorrect installation and ensure the correctness of the direction of the eccentric design and the realization of the overall performance.

[0051] The main force-bearing components are checked for ultimate strength, and the safety factor is greater than or equal to 2.

[0052] The damping device of the present embodiment also has large carrying capacity: as shown in Figure 9The front shock absorber bracket 1 (T-type) is the main load-bearing part. There are 4 bolts at the connection between the bracket 1 and the engine. It is easy to cause danger if the tangential load is supported by only 4 bolts. Therefore, the bottom of the bracket 1 is provided with a protruding anti-shear positioning column 121 groove for positioning with the engine.

[0053] The above structure can greatly improve shear resistance. The reinforcing ribs 10 at the bottom and vertical part of the support frame 7 are also designed to improve shear resistance.

[0054] See Figure 1 and Figure 11 As shown, the main function of the rear shock absorber 200 is to structurally release its own degree of freedom in the thrust direction, balance the deformation posture of the engine, and significantly suppress the relative deformation under pitch posture.

[0055] In this embodiment, see Figures 11-14 As shown, the rear shock absorber 200 includes a support frame 7 and a second rubber assembly 8. The support frame 7 has a first connecting end 701 and a second connecting end 702. A rear locking member 91 passes through the first connecting end 701 to detachably and securely connect the rear shock absorber 200 to the aircraft pylon. The number of second connecting ends 702 is one or more, used for detachably and securely connecting to the main engine mounting brake. The structure of the second rubber assembly 8 may include rubber blocks clamped between two plates, etc., and is not limited here.

[0056] See Figures 11-13 As shown, in this embodiment, there are two second connecting ends 702. The support frame 7 is A-shaped in general. The three ends of the A-shape are a first connecting end 701 and two second connecting ends 702. The second connecting ends 702 are located at the bottom of the support frame 7. Multiple holes for connecting to the engine are provided at the bottom end. The middle is a weight-reducing hollow area 73. The second connecting ends 702 are firmly connected to the main mounting brake of the engine.

[0057] When the engine pitches upwards or downwards, the rear shock absorber 200 is subjected to a vertical force, causing the second rubber assembly 8 to undergo shear or compression deformation, generating a restoring force. Because its mounting position is far from the center of gravity, this restoring force forms an effective restoring torque, thereby suppressing pitch movement.

[0058] As an alternative implementation, see [link to implementation details]. Figures 11-14As shown, the support frame 7 includes a tripod 71 and an end frame 72, wherein: the second connecting end 702 is located at two bottom ends of the tripod 71, the first connecting end 701 is located at the top of the end frame 72, the end frame 72 is provided with fixed holes 721 and mounting grooves 722 arranged at intervals, the rear row locking member 91 passes through the fixed holes 721 to fixedly connect or rotatably connect the end frame 72 with the aircraft pylon; the other end of the tripod extends into the mounting groove 722 and is rotatably connected with the end frame 72, the second rubber assembly 8 is located on one side or opposite sides of the mounting groove 722, and a fixed member 92 (which can be a high-strength bolt) passes through the mounting groove 722 and the second rubber assembly 8 to fix the second rubber assembly 8 at both sides outside the mounting groove 722.

[0059] The other end of the tripod 71 extends into the mounting groove 722 and is rotatably connected with the end frame 72 through a bearing 94, in the embodiment, the bearing 94 at the upper end of the support frame 7 of the rear row damper 200 is connected with the aircraft pylon, the tripod 71 is connected with the engine, and the middle is a flexible structure (the flexible structure is: the structure of the second rubber assembly 8, and the rotatable connection of the tripod 71 and the end frame 72), which can release the degree of freedom and realize the auxiliary damping function at the same time.

[0060] At the same time, considering that the engine will produce axial elongation or shortening due to thermal expansion and contraction during operation, Figure 12 As shown, a size gap is reserved at the matching position of the mounting groove 722 of the end frame 72 and the tripod 71 to form a thermal expansion gap. The gap allows the engine to have a small free movement in the axial direction to compensate for thermal deformation, avoids the generation of excessive thermal stress in the damper, and thus improves the reliability of the entire device under wide temperature range operation.

[0061] Similar to the front row damper 100, referring to Figure 12 The fixed member 92 of the rear row damper 200 is provided with a T-shaped limiting cylinder 93, the cylinder body of the T-shaped limiting cylinder 93 passes through the second rubber assembly 8, and the end of the T-shaped limiting cylinder 93 abuts against the outside of the second rubber assembly 8; the support frame 7 is provided with a weight-reducing hollow area 73.

[0062] The rear row damper 200 is also provided with a T-shaped limiting sleeve 4 as a failure protection mechanism. When the second rubber assembly 8 is partially damaged, it will not be separated from the support frame 7 (consistent with the above-mentioned failure prevention design principle).

[0063] Referring to Figure 1 and Figure 3As shown, the installation method can include the following steps: the engine pre-installed with the vibration damping device of the embodiment of the application is hoisted by ground hoisting equipment to the predetermined installation position under the aircraft pylon, and the engine is linearly lifted in a single vertical upward direction, in the process, the installation interface of the front row of vibration dampers 100 at the lower part of the engine is aligned with and enters the corresponding bearing structure on the aircraft pylon to complete the preliminary docking and positioning. The remaining vibration dampers are fixed, for example, all the front row of vibration dampers 100 are completely and firmly connected with the aircraft pylon through the front row of locking members 3. The rear row of vibration dampers 200 are connected and fixed, and after the fastening and inspection of all the connection points are completed, the installation process of the entire engine is completed. Accordingly, by using the above method, the installation process of the engine can be simplified as hoisting and docking in a single direction, which helps to reduce the need for complex tooling and multi-axial precise alignment, thereby improving the assembly efficiency.

[0064] In this embodiment, vibration damping efficiency analysis is also performed: The analysis of the overall machine vibration damping efficiency requires the following specific conditions: (1) Excitation frequency: combined with the working characteristics of the engine, the vibration load is mainly generated due to the imbalance of the rotor system, including the rotation of the high-pressure rotor, the low-pressure rotor and the propeller blades of the engine.

[0065] According to the project background, the engine excitation frequency mainly includes the frequency: 2000 r / min; (2) Calculate the natural frequency of the selected vibration damper: the natural frequency of the vibration damper depends on its design and material properties, and the modal shape analysis result of the overall machine natural frequency is obtained.

[0066] (3) Frequency ratio (λ): the frequency ratio λ is the ratio of the device disturbance frequency to the natural frequency of the vibration damper, i.e. z = f / f0.

[0067] (4) Calculate the force transmissibility (TA): the force transmissibility TA describes the effect of the vibration damper in reducing vibration transmission. According to the vibration damping principle, the calculation formula of the force transmissibility may be different for different types of vibration dampers.

[0068] (5) Calculate the damping efficiency: the damping efficiency can be calculated by subtracting the force transmissibility TA from 1, i.e. damping efficiency = 1-TA. This formula gives the percentage effect of the vibration damper in reducing vibration transmission.

[0069] Damping ratio and transfer function: the damping effect of the vibration damping installation system mainly considers the isolation of the total vibration energy at the main frequency point of the propeller and in the full frequency domain. The vibration transmissibility is determined by the vibration transmissibility of only two modes, i.e. the highest mode vibration transmissibility of force and torque. According to the modal transmissibility formula, the effectiveness of the engine damping system is commonly measured by the transmissibility, which is defined as:

[0070] Wherein, FT represents the acceleration value of the response point, F0 is the acceleration value of the input point, ζ is the damping ratio ζ = c / cc, the damping coefficient is c, the critical damping cc, and λ is the frequency ratio (i.e. the excitation frequency or the natural frequency of the engine and propeller / the natural frequency of the system or the natural frequency of the damper).

[0071] Wherein the damping ratio is the inherent property of the damping material, and the damping ratio (ζ) is an important concept in structural dynamics, mainly used to describe the standardized damping of the structure. It is the ratio of the damping coefficient to the critical damping coefficient, and has no unit dimension, indicating the form of vibration decay of the structure after being excited. The size of the damping ratio determines the vibration characteristics of the structure, and has an important influence on the stability and reliability of the structure. The size of the damping ratio is related to many factors such as the material, process and surrounding medium of the structure. The selection of the damping ratio is crucial to the stability of the vibration system. By selecting the appropriate damping ratio, the vibration amplitude can be effectively reduced, and the stability and reliability of the system can be improved.

[0072] According to the technical requirements: the damper should have appropriate damping, and try to avoid being in the resonance region, so that the response when the engine starts and stops through the transient resonance is not too large. According to the past experience data, the resonance amplification factor of the engine damping system is not greater than 5.

[0073] The damping ratio (ζ) and the resonance amplification factor are both important parameters in structural dynamics to describe the vibration characteristics of the system, but they each have different meanings and influences. The damping ratio is a dimensionless parameter that indicates the form of vibration decay of the structure after being excited. It is defined as the ratio of the damping coefficient to the critical damping coefficient, and is used to express the size of the structure damping, which is one of the dynamic characteristics of the structure. Referring to Figure 15 , Figure 15 is the relationship curve between the transmission rate and the frequency.

[0074] The size of the damping ratio determines the decay rate and form of vibration of the system, and has an important influence on the stability and reliability of the structure. The resonance amplification factor describes the degree of vibration amplitude amplification of the system at the resonance frequency. When the system is excited by an external excitation close to its natural frequency, the system will resonate, and the vibration amplitude will increase significantly. The resonance amplification factor is used to quantify the degree of amplitude increase. According to the material property requirements, the damping ratio of the damping rubber material is ; Combined with the main excitation frequency of the engine, the damping effect of the damping system at the main working frequency is calculated.

[0075] Table of frequency doubling damping efficiency (%)

[0076] The conclusion of the calculation is that the vibration absorber has a significant damping efficiency at one and two times the frequency, both of which are above 96%, meeting the technical index requirements. The overall damping efficiency is above 80%, meeting the functional requirements for absorbing and reducing the vibration generated by the engine and the supporting propeller.

[0077] In the description of the present specification, a specific feature, structure or characteristic can be combined in any one or more embodiments or examples in a suitable manner.

[0078] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific feature, structure, material or characteristic described can be combined in any one or more embodiments or examples in a suitable manner. Furthermore, the skilled person in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0079] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A dual-plane engine vibration damping device, characterized in that, Includes front and rear shock absorbers for connecting the engine and aircraft pylon, wherein: The front shock absorbers are used to bear the thrust and torque loads of the engine. All front shock absorbers are detachably fixed to the main mounting housing of the engine and located near the center of gravity of the engine. The front shock absorbers fixed to the lower part of the engine are vertically arranged to facilitate direct hoisting of the engine for installation. The rear shock absorber is fixed to the auxiliary mounting box of the engine, structurally releasing its own degree of freedom in the thrust direction, which is used to balance the deformation attitude of the engine and significantly suppress the relative deformation in the pitch attitude.

2. The dual-plane engine vibration damping device according to claim 1, characterized in that, All of the aforementioned front shock absorbers are arranged at intervals on the main mounting brake of the engine, and are inclined relative to the front shock absorbers fixed to the upper part of the engine. The number of rear shock absorbers is one or two. When the number of rear shock absorbers is two, the rear shock absorbers are arranged symmetrically about the axis of the engine, either vertically or horizontally.

3. The dual-plane engine vibration damping device according to claim 1, characterized in that, The front shock absorber includes a bracket and a first rubber assembly, wherein: The bracket is used for detachable and fixed connection with the engine. The first rubber assembly is fixed to the front and / or rear side of the bracket. A front locking member passes through the bracket and all the first rubber assemblies to fix the front shock absorber and the aircraft rack. The center of the front shock absorber is set off-center relative to the center of the front locking member to resist the counter-torque generated by the propeller rotation on the engine.

4. The dual-plane engine vibration damping device according to claim 3, characterized in that, The front shock absorber also includes a limiting sleeve, which passes through the first rubber assembly and the bracket. The bracket is provided with a limiting groove, and the limiting sleeve extends into the limiting groove. The front locking member passes through the limiting sleeve to fix the front shock absorber and the aircraft rack in place. The limiting sleeve cooperates with the inner wall of the limiting groove to limit the displacement of the front shock absorber.

5. The dual-plane engine vibration damping device according to claim 3, characterized in that, The first rubber assembly includes a front support plate, an elastic rubber plate, and a rear cover plate, wherein: The front support plate and the rear cover plate clamp and fix the elastic rubber plate, and the three are vulcanized integral molding structures.

6. The dual-plane engine vibration damping device according to claim 3, characterized in that, The bracket includes an integrally formed base and a support plate, wherein: The base is perpendicular to the support plate, and the base is provided with holes for fixed connection with the engine; The support plate and / or the base are provided with weight reduction holes. The first rubber assembly is fixed to the front and rear sides of the support plate. A first gasket is clamped and fixed between the first rubber assembly and the support plate. A second gasket is installed at the bottom of the base. A reinforcing rib is provided between the support plate and the base.

7. The dual-plane engine vibration damping device according to claim 3, characterized in that, Of the bracket and the first rubber component, one is provided with a positioning hole and the other is provided with a positioning post. There are at least two positioning holes of different sizes and at least two positioning posts of different sizes. The positioning holes and the corresponding positioning posts are inserted and matched to ensure that the first rubber component and the bracket are accurately installed. The bottom of the bracket is provided with a protruding shear positioning post for positioning with the engine.

8. The dual-plane engine vibration damping device according to claim 1, characterized in that, The rear shock absorber includes a support frame and a second rubber assembly, wherein: The support frame has a first connecting end and a second connecting end, and a rear locking member passes through the first connecting end and the support frame, thereby detachably and fixedly connecting the rear shock absorber to the aircraft rack. The number of the second connection ends is one or more, for detachable and fixed connection with the engine.

9. The dual-plane engine vibration damping device according to claim 8, characterized in that, The support frame includes a tripod and end frames, wherein: The second connecting end is located at the two bottom ends of the tripod, and the first connecting end is located at the top of the end frame. The end frame is provided with spaced fixing holes and mounting slots. The rear locking member passes through the fixing holes to fix or rotate the end frame to the aircraft rack, thereby allowing the rear shock absorber to structurally release its degree of freedom in the thrust direction. The other end of the tripod extends into the mounting groove and is rotatably connected to the end frame. The second rubber assembly is located on one side or opposite sides of the mounting groove. A fixing member passes through the mounting groove and the second rubber assembly fixes the second rubber assembly at the mounting groove.

10. The dual-plane engine vibration damping device according to claim 9, characterized in that, The fastener is fitted with a T-shaped limiting tube, the body of which passes through the second rubber assembly, and the end of which abuts against the outside of the second rubber assembly. The support frame is provided with a weight-reducing hollow area.

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