A turboprop engine layout method and vibration reduction system

Abstract

This invention discloses a turboprop engine arrangement method and a vibration reduction system. The turboprop engine is arranged through a vibration reduction system, which includes a front vibration damper, a front upper vibration damper, and a rear vibration damper installed between the aircraft frame and the turboprop engine. A torque compensation device is also provided on the aircraft frame and connected to the front vibration damper. The turboprop engine arrangement method includes optimizing the pre-compression method of the rubber components in the rear vibration damper. Specifically, the rear vibration damper includes a main support assembly, and the rubber components include rubber component one and rubber component two. The main support assembly is located between rubber component one and rubber component two. During installation, the main bolt passes through the middle position of rubber component two, the middle position of the main support assembly and rubber component one in sequence, and is then locked with a nut, thereby pressing rubber component two and rubber component one onto the bottom and top surfaces of the main support assembly, so that the rubber bodies in rubber component two and rubber component one are in a pre-compressed state.

Description

Technical Field

[0001] This invention relates to a turboprop engine arrangement method and vibration reduction system, belonging to the field of turboprop engine vibration reduction technology. Background Technology

[0002] A turboprop engine is an engine that combines jet thrust and propeller thrust, integrating the characteristics of both engines. This results in superior performance in low-speed flight and short takeoff and landing. Therefore, turboprop engines are widely used in small aircraft, helicopters, drones, and other aircraft.

[0003] When a turboprop engine is operating, the rotation of the propeller generates significant vibrations, making vibration issues more pronounced compared to other types of aero engines. Vibration adversely affects the engine's performance, potentially leading to wear and fatigue of engine components, thus shortening its service life. Simultaneously, vibration can damage the aircraft's structure, such as inducing structural fatigue cracks, thereby jeopardizing the airframe's lifespan and safety. Therefore, vibration damping systems are typically installed between the engine and the aircraft frame to absorb and isolate vibration energy. Furthermore, the propeller rotation generates a significant torque on the turboprop engine; therefore, the structural torsional resistance under high torsional conditions must be considered concurrently with the installation of vibration damping systems.

[0004] Chinese invention patent application CN116039935A, published on May 2, 2023, discloses a vibration damping mounting system for a large turboprop passenger aircraft engine. The system includes: a turboprop engine with a front mounting surface near the propeller and a rear mounting surface near the turbine combustion chamber; the front mounting surface has two mounting points and three front mounting sections; the rear mounting surface has two rear mounting sections; and mechanical or hydraulic torque compensation devices are installed at the two mounting points. The three front mounting sections include a first front mounting section and two second front mounting sections. The first front mounting section is located at the apex of the front mounting surface, and the two second front mounting sections are symmetrically arranged along the longitudinal vertical plane of the engine. A front upper vibration damping device is installed at the first front mounting section, and a front side vibration damping device is installed at the second front mounting sections. The two rear mounting sections are symmetrically arranged along the longitudinal vertical plane of the engine, and rear side vibration damping devices are installed at the two rear mounting sections.

[0005] Although the aforementioned patent document discloses a vibration reduction installation system for a large turboprop passenger aircraft engine, some problems have been found in actual use, so it is necessary to further optimize its design.

[0006] In summary, how to design a turboprop engine layout method and vibration reduction system to further optimize the product's performance, improve its practicality in propeller aircraft, and give it better application prospects is an urgent technical problem to be solved. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to address the deficiencies in the prior art by providing a turboprop engine arrangement method and vibration reduction system, which further optimizes the various performance characteristics of the product, improves its practicality in propeller aircraft, and gives it better application prospects.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a turboprop engine arrangement method, wherein the turboprop engine is arranged on the aircraft frame via a vibration damping system, the vibration damping system comprising: two front vibration dampers and one front upper vibration damper installed between the aircraft frame and the turboprop engine near the front side of the engine; two rear vibration dampers installed between the aircraft frame and the turboprop engine near the rear side of the engine; a torque compensation device is also provided on the aircraft frame at the front side of the engine, the torque compensation device being connected to the two front vibration dampers; the two front vibration dampers and the two rear vibration dampers are respectively located on both sides of the turboprop engine. The front upper shock absorber is located at the top of the turboprop engine. The turboprop engine arrangement method includes optimizing the pre-compression method of the rubber components in the rear shock absorber. Specifically, the rear shock absorber also includes a main support assembly. The rubber components include rubber component one and rubber component two. The main support assembly is located between rubber component one and rubber component two. During installation, the main bolt passes through the middle position of rubber component two, the middle position of the main support assembly and rubber component one in sequence, and is then locked with a nut. This presses rubber component two and rubber component one onto the bottom and top surfaces of the main support assembly, so that the rubber bodies in rubber component two and rubber component one are in a pre-compressed state.

[0009] Preferably, both the second rubber component and the first rubber component include a top plate, a bottom plate, and a bottom plate. The rubber body in both the second rubber component and the first rubber component includes a rubber stack and a rubber stack. The bottom plate is vulcanized and bonded to the top plate through the rubber stack, and the bottom plate is vulcanized and bonded to the top plate through the rubber stack. The rubber stack and the rubber stack are located at both ends of the top plate, and a through hole is opened in the middle of the top plate.

[0010] During installation, the main bolt passes through the through hole of rubber component two, the through hole of the main support component, and the through hole of rubber component one in sequence, and is then locked with the nut. After locking, the bottom plate one and bottom plate two of rubber component two contact the bottom surface of the main support component, and the bottom plate one and bottom plate two of rubber component one contact the top surface of the main support component.

[0011] Preferably, the main bolt passing through the main support assembly is connected to one end of the mounting bracket assembly via a ball bearing, and a bushing 1 and a bushing 2 are also sleeved on the outside of the main bolt; the bushing 1 is located between the top plate of the rubber assembly 1 and the ball bearing 1, and the bushing 2 is located between the top plate of the rubber assembly 2 and the ball bearing 1.

[0012] Before pre-compression, one end of bushing one is in contact with the top plate of rubber assembly one, and the other end of bushing one has a gap H1 between it and the end face of the inner ring of ball bearing one. One end of bushing two is in contact with the top plate of rubber assembly two, and the other end of bushing two has a gap H2 between it and the end face of the inner ring of ball bearing one. After the main bolt is tightened for pre-compression, both gaps H1 and H2 are zero.

[0013] By designing the values ​​of gaps H1 and H2, the pre-compression of the rubber bodies in rubber component two and rubber component one can be controlled.

[0014] Preferably, the optimization method for the turboprop engine vibration reduction system further includes optimizing the rigid limiting structure of the rubber component in the rear shock absorber, namely: the mounting bracket assembly includes a mounting bracket frame, and a ball bearing mounting hole is provided at one end of the mounting bracket frame; the main support assembly includes a main support frame, and a through hole is provided at the middle position of the main support frame; when one end of the mounting bracket assembly is inserted into one side of the main support assembly, the central axis of the ball bearing mounting hole coincides with the central axis of the through hole; after installation, the ball bearing is positioned between the outside of the main bolt and the ball bearing mounting hole, so that the main bolt passing through the main support assembly is connected to one end of the mounting bracket assembly through the ball bearing.

[0015] Both bushing one and bushing two are located in through hole three, and there is a gap H4 between the outer peripheral surface of bushing one and the inner peripheral surface of through hole three, and a gap H5 between the outer peripheral surface of bushing two and the inner peripheral surface of through hole three.

[0016] When subjected to excessive impact or vibration, a rigid limiting structure is formed through the contact between the outer circumferential surfaces of bushing one and bushing two and the inner circumferential surface of through hole three.

[0017] Preferably, the turboprop engine arrangement method further includes optimizing the installation method between the rear shock absorber and the aircraft frame, namely: providing a ball bearing second mounting hole and a ball bearing third mounting hole on the main support assembly, wherein the ball bearing in the screw with ball bearing is ball bearing second, and the ball bearing in the screw with ball bearing is ball bearing third.

[0018] After installation, ball bearing 2 is positioned between one end of screw 1 and the mounting hole of ball bearing 2, so that one end of screw 1 is connected to the main support assembly through ball bearing 2. Ball bearing 3 is positioned between one end of screw 2 and the mounting hole of ball bearing 3, so that one end of screw 2 is connected to the main support assembly through ball bearing 3. The other ends of screw 1 and screw 2 are both connected to the aircraft frame.

[0019] Preferably, a mounting arm one and a mounting arm two are provided on the aircraft frame, a mounting through hole one is provided at one end of the mounting arm one, and a mounting through hole two is provided at one end of the mounting arm two.

[0020] During connection, the other end of screw one is passed through mounting through hole one and locked with mounting nut one, and the other end of screw two is passed through mounting through hole two and locked with mounting nut two, so that the other ends of screw one and screw two are connected to the aircraft frame.

[0021] Preferably, the main support assembly further includes a rotating arm, a connecting arm and a hanging ear are provided on one side of the main support frame, the connecting arm and the hanging ear are integral with the main support frame, one end of the rotating arm is hinged to the hanging ear, a second ball bearing mounting hole is provided on the connecting arm, and a third ball bearing mounting hole is provided on the other end of the rotating arm.

[0022] During connection, first connect the first screw with ball bearing to the first mounting arm. After connection, adjust the installation position of the second screw with ball bearing according to the actual position of the second mounting through hole, and then connect the second screw with ball bearing to the second mounting arm.

[0023] Preferably, the turboprop engine arrangement method includes optimization of the hydraulic anti-torsion device of the engine vibration damping system. Specifically, the hydraulic anti-torsion device of the engine vibration damping system includes: an actuator, a connecting pipe, and an accumulator. The actuator includes a first actuator and a second actuator, each actuator having an actuating rod. The oil storage ends of the first actuator and the second actuator are at different vertical positions, and are connected via a connecting pipe. The accumulator is connected to the connecting pipe. The actuating rod includes a first actuating rod and a second actuating rod, both connected to the engine. The first actuating rod is located within the first actuator; the second actuating rod is located within the second actuator.

[0024] The optimization of the hydraulic anti-torsion device of the engine vibration reduction system involves designing the actuator as a piston sealing ring, a hydraulic chamber, and a radial support portion; the piston sealing ring is an annular structure that contacts the inner wall of the hydraulic chamber and is disposed on the actuating rod; the actuating rod extends upward to the outside of the hydraulic chamber; the radial support portion provides radial support for the actuating rod when it moves.

[0025] Preferably, the accumulator includes: an energy storage chamber, a spring, an indicator rod, and an accumulator piston; the energy storage chamber has a storage end and a pressure end, the storage end being connected to a hydraulic system connecting pipe; the indicator rod and the spring are disposed at the pressure end, the indicator rod is connected to the accumulator piston and moves with the accumulator piston, and the hydraulic system pressure can be detected by detecting the position of the indicator rod; the spring is sleeved on the indicator rod and presses against the accumulator piston to compensate for the hydraulic system pressure.

[0026] The present invention also discloses a vibration damping system, comprising: two front vibration dampers and one front upper vibration damper installed near the front of the engine between the aircraft frame and the turboprop engine; two rear vibration dampers installed near the rear of the engine between the aircraft frame and the turboprop engine; a torque compensation device is also provided on the aircraft frame at the front of the engine, and the torque compensation device is connected to the two front vibration dampers; the two front vibration dampers and the two rear vibration dampers are respectively located on both sides of the turboprop engine, and the front upper vibration damper is located at the top of the turboprop engine; the rear vibration dampers include a rubber assembly and a main support assembly; the rubber assembly includes rubber assembly one and rubber assembly two; the main support assembly is disposed between rubber assembly one and rubber assembly two; during installation, a main bolt is used to pass through the middle position of rubber assembly two, the middle position of the main support assembly and rubber assembly one in sequence, and then locked with a nut, thereby pressing rubber assembly two and rubber assembly one onto the bottom and top surfaces of the main support assembly, so that the rubber bodies in rubber assembly two and rubber assembly one are in a pre-compressed state.

[0027] The beneficial effects of this invention are as follows: By optimizing the connection method between the rear damper, the front damper, and the torque compensation device, and by optimizing the torque compensation device itself, this invention further optimizes the various performance aspects of the product, improves its practicality in propeller aircraft, and gives it better application prospects. By placing the main bolt connection position between the two rubber stacks of rubber assembly two and rubber assembly one, only one main bolt is needed to press rubber assembly two and rubber assembly one onto the bottom and top surfaces of the main support assembly. This allows for pre-compression of the rubber bodies in rubber assembly two and rubber assembly one, thus reducing the number of connecting bolts compared to existing technologies, simplifying the pre-compression structure of the rubber assemblies, simplifying the installation steps, and reducing the weight of the entire rear damping device, meeting the requirements of lightweight design. Furthermore, this arrangement also reduces the area of ​​the third metal frame in existing technologies, further reducing the weight of the entire rear damping device. By designing the values ​​of gaps H1 and H2, precise control is achieved over the pre-compression of the rubber components in rubber assembly one and two. After the bolts and nuts reach the designed tightening torque, the bushings create a rigid metal limit to ensure the rubber remains in its designed compression state, preventing the rubber components from loosening under engine load conditions. When subjected to excessive impact or vibration, a rigid limiting structure is formed through the contact between the outer circumferential surfaces of bushing one and two and the inner circumferential surface of through hole three. This limits the deformation of the shock absorber under excessive impact or vibration, protecting both the shock absorber and the engine from damage and ensuring the shock absorber operates within its predetermined stroke range, avoiding malfunctions or damage caused by exceeding the design limits. Through optimized connection methods, this invention enables the connection between the front shock absorber and the torque compensation device. This allows the torque compensator to automatically adjust its output torque when the load changes, maintaining stable engine operation, reducing vibration and noise levels, and thus improving flight safety and comfort. By designing the nut as an elastic nut, its elastic support rests on the inner circumference of the through hole. The through hole then acts as a limit for the rotation of the elastic nut, effectively preventing axial movement within the through hole. During operation, the elastic nut is moved to the inserted bolt shank, and then the rotating bolt engages with the limiting elastic nut for locking. This allows for convenient and quick bolt tightening in confined installation spaces, reducing workload and increasing efficiency. Furthermore, by using a positioning disc that mates with the positioning through hole to form a positioning structure, workload is further reduced, and efficiency is improved. An optimized torque compensation device limits the reaction torque generated by the engine propeller. The device also features a radial support section that provides radial support to the actuator rod, and this radial support section engages with the first limiting hole to provide radial support to the actuator rod. Specifically, the radial support section can be a support structure on the actuator rod or a support ring on the hydraulic chamber.It can prevent hydraulic oil leakage caused by the displacement of the hydraulic device actuator rod due to the radial force of the engine, and the gap between the piston sealing ring and the cylinder wall. Attached Figure Description

[0028] Figure 1 A three-dimensional structural diagram of an engine mounted on an aircraft frame via a vibration damping system according to an embodiment of the present invention;

[0029] Figure 2 This refers to the pre-compression method for rear-side shock absorbers in existing technologies.

[0030] Figure 3 This is a three-dimensional structural diagram of the rear shock absorber in an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the exploded disassembly structure of the rear shock absorber in an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the axial cross-sectional structure of the rear shock absorber in an embodiment of the present invention;

[0033] Figure 6 This is a three-dimensional structural diagram of rubber component one in an embodiment of the present invention. Figure 1 ;

[0034] Figure 7 This is a top view of the rear shock absorber in an embodiment of the present invention;

[0035] Figure 8 This is a three-dimensional structural diagram of the main support assembly in an embodiment of the present invention;

[0036] Figure 9 This is a three-dimensional structural diagram of rubber component one in an embodiment of the present invention. Figure 2 ;

[0037] Figure 10 This is a three-dimensional structural diagram of the mounting bracket assembly in an embodiment of the present invention;

[0038] Figure 11 for Figure 5 A schematic diagram of a partial axial section of the structure located at the main bolt;

[0039] Figure 12 for Figure 11 Enlarged structural diagram of section A in the middle;

[0040] Figure 13 for Figure 11 Enlarged structural diagram of section B;

[0041] Figure 14 This is a three-dimensional structural diagram of the installation connection between the main support assembly and the aircraft frame in an embodiment of the present invention.

[0042] Figure 15 This is a partial three-dimensional structural diagram of the connection between the front shock absorber and the torque compensation device in an embodiment of the present invention;

[0043] Figure 16 This is a partial cross-sectional view of the main mounting bracket of the front shock absorber in an embodiment of the present invention;

[0044] Figure 17 This is a partial cross-sectional view of the structure when the front shock absorber and the torque compensation device are connected in an embodiment of the present invention.

[0045] Figure 18 This is a partial cross-sectional view of the structure before the nut is inserted into the through hole during the connection process in this embodiment of the invention.

[0046] Figure 19 This is a partial cross-sectional view of the structure after the nut is inserted into the through hole during the connection process in an embodiment of the present invention.

[0047] Figure 20 This is a three-dimensional structural diagram of the elastic nut in an embodiment of the present invention;

[0048] Figure 21 This is a three-dimensional structural diagram of the right elastic part in an embodiment of the present invention;

[0049] Figure 22 This is a schematic diagram of the front view of the right elastic part in an embodiment of the present invention;

[0050] Figure 23 This is a schematic diagram of the axial cross-sectional structure of the left nut portion in an embodiment of the present invention;

[0051] Figure 24 This is a three-dimensional structural diagram of the left nut portion in an embodiment of the present invention;

[0052] Figure 25 This is a schematic diagram of the axial cross-sectional structure of the nut sleeve of the left nut portion in an embodiment of the present invention;

[0053] Figure 26 This is an exploded three-dimensional structural diagram of the left nut portion in an embodiment of the present invention;

[0054] Figure 27 This is a schematic diagram of the hydraulic anti-torsion device of the engine vibration reduction system hydraulic anti-torsion device in an embodiment of the present invention;

[0055] Figure 28 This is a three-dimensional structural diagram of the hydraulic anti-torsion device of the engine vibration reduction system in an embodiment of the present invention;

[0056] In the diagram: 1. Engine, 2. Aircraft frame, 211. Mounting arm one, 212. Mounting arm two, 3. Front shock absorber, 4. Front upper shock absorber, 5. Rear shock absorber, 6. Torque compensation device, 7. Third connecting bolt, 8. Fourth connecting bolt, 9. Third metal frame, 10. Rubber body, 11. Rubber assembly one, 12. Rubber assembly two, 13. Main support assembly, 131. Main support frame, 132. Through hole one, 133. Through hole two, 134. Through hole three, 135. Ball bearing two mounting hole, 136. Ball bearing three mounting hole, 137. Swing arm, 138. Connecting arm, 139. Hanger 14. Ear, 141. Mounting bracket assembly, 142. Ball bearing mounting hole 1, 15. Main bolt, 16. Main nut, 17. Ball bearing 1, 171. Inner ring, 18. Screw 1, 19. Screw 2, 20. Top plate, 201. Countersunk hole, 21. Base plate 1, 22. Base plate 2, 23. Rubber stack 1, 24. Rubber stack 2, 25. Through hole, 26. Positioning protrusion 1, 27. Positioning protrusion 2, 28. Screw, 29. Ball bearing 2, 30. Ball bearing 3, 31. Bushing 1, 32. Bushing 2, 33. Flange, 34. Mounting nut 1, 35. Mounting nut 2, 36. Connecting 37. Main mounting bracket, 38. Main mounting bracket through hole one, 39. Main mounting bracket through hole two, 40. Main mounting bracket through hole three, 41. Ball bearing four, 42. Connecting rod, 43. Bolt, 431. Bolt shank, 44. Nut, 45. Left nut part, 46. Right elastic part, 461. Spring body, 4611. Spring body cavity, 462. Upper clip, 463. Lower clip, 47. Nut seat, 471. Seat body, 472. Seat body top plate, 473. Seat body bottom plate, 474. Seat body inner cavity, 48. Nut sleeve, 481. Sleeve body, 482. Sleeve body flange, 483. Sleeve body 49. Cavity; 50. Thread; 51. Inner conical surface; 52. Stop bar one; 53. Stop bar two; 54. Stop bar mounting hole one; 55. Sleeve mounting space; 56. Positioning disc; 57. Connecting disc; 58. Positioning through hole; 59. Actuator; 60. Connecting pipe; 60. Accumulator; 601. Accumulation chamber; 602. Spring; 603. Indicator rod; 604. Accumulator piston; 605. Accumulator through hole; 61. Actuating rod; 62. Oil reservoir end; 63. Piston sealing ring; 64. Hydraulic chamber; 65. Radial support part; 66. First limiting hole; 67. Second limiting hole; 68. Connecting hole; 69. Throttling hole. Detailed Implementation

[0057] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0058] Example: Figure 1As shown, along the length of the turboprop engine 1, the side closer to the turboprop is designated as the engine's front side, and the opposite side is designated as the engine's rear side. A turboprop engine arrangement method involves mounting it to the aircraft frame via a vibration damping system. This system includes: two front-side vibration dampers 3 and one front upper vibration damper 4, installed near the engine's front side between the aircraft frame 2 and the turboprop engine 1; two rear-side vibration dampers 5, installed near the engine's rear side between the aircraft frame 2 and the turboprop engine 1; a torque compensation device 6 is also installed on the aircraft frame 2 at the engine's front side, connected to the two front-side vibration dampers 3; the two front-side vibration dampers 3 and the two rear-side vibration dampers 5 are located on opposite sides of the turboprop engine 1, and the front upper vibration damper 4 is located at the top of the turboprop engine 1. The turboprop engine 1 is connected to the aircraft frame 2 via these vibration dampers.

[0059] First, in this embodiment, the rear shock absorber was optimized:

[0060] As can be seen from the patent documents cited in the background section, existing rear shock absorbers include a rubber stack, such as the third rubber stack in this patent document. After the rear shock absorber is installed, this third rubber stack is in a pre-compressed state. To achieve this pre-compression state, the prior art uses two connecting bolts, such as the third and fourth connecting bolts in this patent document. However, using two connecting bolts to pre-compress the rubber stack results in complex structure and cumbersome installation steps; furthermore, using two connecting bolts to pre-compress the rubber stack increases the weight of the entire rear shock absorber, which is extremely detrimental to aircraft flight in aircraft engine applications.

[0061] The applicant, through further research, discovered in the patent literature of the prior art mentioned in the background section, such as Figure 2 As shown, the third metal frame 9 on both sides of the rubber stack is clamped by the third connecting bolt 43 and the fourth connecting bolt 8, thereby pre-compressing the two rubber bodies 10 in the rubber stack. Further research by the applicant revealed that the third connecting bolt 43 and the fourth connecting bolt 8 are located on opposite sides of the two rubber bodies 10. In this positional distribution, reducing the position of either connecting bolt would result in one side of the rubber body 10 being compressed while the other side remains loose. Therefore, in this positional distribution, two connecting bolts are necessary for pre-compression of the rubber bodies. This leads to the aforementioned problems of structural complexity, cumbersome installation steps, and increased weight of the entire rear vibration damping device.

[0062] Therefore, the applicant made the following optimizations:

[0063] like Figures 3 to 5 As shown, the rear shock absorber in this embodiment includes a rubber assembly 11, a rubber assembly 12, a main support assembly 13 disposed between the rubber assembly 11 and the rubber assembly 12, and a mounting bracket assembly 14 disposed on one side of the main support assembly 13. One end of the mounting bracket assembly 14 is inserted into the main support assembly 13. A main bolt 15 passes through the rubber assembly 12, the main support assembly 13, and the rubber assembly 11 in sequence and is then locked with a main nut 16, thereby pressing the rubber assembly 12 and the rubber assembly 11 against the bottom and top surfaces of the main support assembly 13. This results in the rubber bodies in the rubber assembly 12 and the rubber assembly 11 being in a pre-compressed state. The main bolt 15, passing through the main support assembly 13, is connected to one end of the mounting bracket assembly 14 via a ball bearing 17. The other end of the mounting bracket assembly 14 is connected to a turboprop engine (not shown in the figure). The other side of the main support assembly 13 is connected to the aircraft frame (not shown in the figure) via a screw 18 with a ball bearing and a screw 19 with a ball bearing. By installing the aforementioned rear-side vibration damper between the turboprop engine and the aircraft frame to absorb and isolate vibration energy, the service life of the turboprop engine is improved, ensuring the safety of the aircraft body.

[0064] The structures of rubber component 2 12 and rubber component 11 are the same. Taking rubber component 11 as an example, as follows: Figure 6 As shown, the rubber assembly 11 includes a top plate 20, a bottom plate 21, and a bottom plate 22. The rubber body includes a rubber stack 23 and a rubber stack 24. The bottom plate 21 is vulcanized and bonded to the top plate 20 via the rubber stack 23, and the bottom plate 22 is vulcanized and bonded to the top plate 20 via the rubber stack 24. The rubber stacks 23 and 24 are located at both ends of the top plate 20, and a through hole 25 is formed in the middle of the top plate 20. During installation, the main bolt 15 passes through the through hole 25 of the rubber assembly 12, the main support assembly 13, and the through hole 25 of the rubber assembly 11 in sequence, and is then locked with the main nut 16. After locking, the bottom plates 21 and 22 of the rubber assembly 12 contact the bottom surface of the main support assembly 13, and the bottom plates 21 and 22 of the rubber assembly 11 contact the top surface of the main support assembly 13. Figure 7As shown, in this embodiment, the connection position of the main bolt 15 is set between the two rubber stacks of rubber assembly 2 12 and rubber assembly 11. Thus, by using only one main bolt 15 to press rubber assembly 2 12 and rubber assembly 11 onto the bottom and top surfaces of the main support assembly 13, the rubber bodies in rubber assembly 2 12 and rubber assembly 11 can be pre-compressed. Compared with the prior art, this reduces the number of connecting bolts, simplifies the pre-compression structure of the rubber components, simplifies the installation steps, and reduces the weight of the entire rear vibration damping device, meeting the requirements of lightweight design. Furthermore, this arrangement also reduces the area of ​​the third metal frame (i.e., the top plate in this embodiment) in the prior art, further reducing the weight of the entire rear vibration damping device.

[0065] like Figure 8 and Figure 9 As shown, the main support assembly 13 includes a main support frame 131, on which a first through hole 132 and a second through hole 133 are provided. On the bottom plate 21 and bottom plate 22 of the second rubber assembly 12 and the first rubber assembly 11, respectively, a first positioning protrusion 26 and a second positioning protrusion 27 are provided. The shapes of the first positioning protrusion 26 and the second positioning protrusion 27 match the first through hole 132 and the second through hole 133. When rubber component 2 12 and rubber component 11 are pressed onto the bottom and top surfaces of the main support assembly 13, the positioning protrusions 1 26 and 27 of rubber component 11 are respectively inserted into one end of the through hole 132 and one end of the through hole 133 on the main support frame 131, and the positioning protrusions 1 26 and 27 of rubber component 2 12 are respectively inserted into the other end of the through hole 132 and the other end of the through hole 133 on the main support frame 131. This positions the rubber components 2 12 and 11 when pressed onto the bottom and top surfaces of the main support assembly 13, which can further improve the assembly accuracy and speed of the rear shock absorber. In addition, the through holes 1 and 2 can also reduce the weight of the main support frame, thereby further meeting the requirements of lightweight design.

[0066] like Figure 8 and Figure 10 As shown, the mounting bracket assembly 14 includes a mounting bracket frame 141, with a ball bearing mounting hole 142 at one end of the mounting bracket frame 141. A third through hole 134 is also provided on the main support frame 131, located between the first through hole 132 and the second through hole 133. Figure 5As shown, when one end of the mounting bracket assembly 14 is inserted into one side of the main support assembly 13, the central axis of the ball bearing mounting hole 142 coincides with the central axis of the through hole 134; after installation, the ball bearing 17 is positioned between the outside of the main bolt 15 and the ball bearing mounting hole 142, thereby allowing the main bolt 15, which passes through the main support assembly 13, to be connected to one end of the mounting bracket assembly 14 via the ball bearing 17. Figure 10 As shown, the other end of the mounting frame 141 is connected to the turboprop engine (not shown) by screws 28.

[0067] like Figure 8 As shown, a second ball bearing mounting hole 135 and a third ball bearing mounting hole 136 are provided on the other side of the main support assembly 13. The ball bearing in the first screw 18 with a ball bearing is a second ball bearing 29, and the ball bearing in the second screw 19 with a ball bearing is a third ball bearing 30. After installation, the second ball bearing 29 is positioned between one end of the first screw 18 and the second ball bearing mounting hole 135, so that one end of the first screw 18 is connected to the other side of the main support assembly 13 through the second ball bearing 29. The ball bearing 30 is positioned between one end of the screw 2 19 and the mounting hole 136 of the ball bearing 3, so that one end of the screw 2 19 is connected to the other side of the main support assembly 13 through the ball bearing 30. The other ends of the screw 1 18 and the screw 2 19 are both connected to the aircraft frame (not shown in the figure). Thus, through the above structure, the other side of the main support assembly 13 is connected to the aircraft frame (not shown in the figure) through the screw 1 18 with the ball bearing and the screw 2 19 with the ball bearing.

[0068] This embodiment connects the main support assembly to the aircraft frame by designing two screws with ball bearings, one with a ball bearing and the other with a ball bearing. This allows the rear shock absorber to have more installation redundancy in all directions, which can compensate for installation gaps and improve the safety, reliability and convenience of installing and using the rear shock absorber.

[0069] To further refine the control of the pre-compression of the rubber components in rubber component two and rubber component one, the applicant made further improvements, such as... Figure 11 and Figure 12As shown, a first bushing 31 and a second bushing 32 are also sleeved on the outside of the main bolt 15. The first bushing 31 is located between the top plate 20 of the rubber assembly 11 and the ball bearing 17, and the second bushing 32 is located between the top plate 20 of the rubber assembly 12 and the ball bearing 17. Before pre-compression, one end of the first bushing 31 is in contact with the top plate 20 of the rubber assembly 11, and a gap H1 is left between the other end of the first bushing 31 and one end face of the inner ring 171 of the ball bearing 17. One end of the bushing 32 contacts the top plate 20 of the rubber assembly 12, and the other end of the bushing 32 has a gap H2 between it and the other end face of the inner ring 171 of the ball bearing 17. When the main bolt 15 is tightened for pre-compression, both gaps H1 and H2 are zero, meaning that the other end of the bushing 31 contacts the end face of the inner ring 171 of the ball bearing 17, and the other end of the bushing 32 contacts the other end face of the inner ring 171 of the ball bearing 17. By using rigid limiting between the bushing and the ball bearing, the pre-compression of the rubber components in the rubber assembly 1 and 2 can be precisely controlled through the design of gaps H1 and H2. After the bolt and nut reach the designed tightening torque, the bushing generates a rigid metal limit to ensure the designed compression state of the rubber, ensuring that the rubber components of the rear shock absorber do not loosen under engine load conditions. Additionally, it should be noted that after pre-compression, bushing one and bushing two can be used to axially limit the ball bearing.

[0070] like Figure 13 As shown, flanges 33 are provided on the outer circumferential surfaces of one end of bushing 31 and bushing 32. Countersunk holes 201 are provided on the top plates 20 of rubber assembly 11 and rubber assembly 22. When one end of bushing 31 and bushing 32 contacts the top plate 20, one end of bushing 31 and bushing 32 is inserted into the countersunk holes 201 on the top plates 20 of rubber assembly 11 and rubber assembly 22 respectively. The flanges 33 on one end of bushing 31 and bushing 32 contact the top plates 20 of rubber assembly 11 and rubber assembly 22 respectively. At this time, a gap H3 is left between one end of bushing 31 and bushing 32 and the bottom surface of the countersunk holes 201 on the top plates 20 of rubber assembly 11 and rubber assembly 22.

[0071] like Figure 4 , Figure 8 and Figure 14As shown, in this embodiment, when connecting the aircraft frame, mounting arm 1 211 and mounting arm 212 are provided on the aircraft frame 2. A mounting through hole 1 (not shown in the figure) is provided on one end of mounting arm 1 211, and a mounting through hole 2 (not shown in the figure) is provided on one end of mounting arm 212. During connection, the other end of screw 18 is passed through mounting through hole 1 and locked with mounting nut 1 34, and the other end of screw 2 19 is passed through mounting through hole 2 and locked with mounting nut 2 35, so that the other ends of screw 18 and screw 2 19 are connected to the aircraft frame 2.

[0072] The main support assembly 13 also includes a rotating arm 137. A connecting arm 138 and a hanging ear 139 are provided on one side of the main support frame 131. The connecting arm 138 and the hanging ear 139 are integral with the main support frame 131. One end of the rotating arm 137 is hinged to the hanging ear 139 by a connecting pin 36. A second ball bearing mounting hole 135 is provided on the connecting arm 138, and a third ball bearing mounting hole 136 is provided on the other end of the rotating arm 137. Due to various factors, the relative positions of mounting through holes one and two on the aircraft frame 2 are uncertain. Therefore, in existing technologies, installation difficulties often arise during connection. In this embodiment, during installation, the screw 18 with ball bearing is first connected to the mounting arm 1. After connection, due to the hinge structure between the rotating arm 137 and the lug 139, the installation position of the screw 19 with ball bearing can be adjusted according to the actual position of the mounting through hole 2. This allows the screw 19 with ball bearing to be easily connected to the mounting arm 2, further improving the ease of installation and use of the rear shock absorber. In addition, the connecting arm 138 and the main support frame 131 are designed as an integral structure. Compared with existing technologies, this reduces one hinge point, making the rear shock absorber more stable during vibration damping operation.

[0073] like Figure 11 and Figure 12 As shown, both bushing 31 and bushing 32 are located in through hole 134, with a gap H4 between the outer circumferential surface of bushing 31 and the inner circumferential surface of through hole 134, and a gap H5 between the outer circumferential surface of bushing 32 and the inner circumferential surface of through hole 134. When subjected to excessive impact or vibration, a rigid limiting structure is formed by the contact between the outer circumferential surfaces of bushing 31 and bushing 32 and the inner circumferential surface of through hole 134. This allows the embodiment to limit the deformation of the shock absorber when subjected to excessive impact or vibration, thereby protecting the shock absorber and engine from damage, ensuring that the shock absorber operates within a predetermined stroke range, and avoiding malfunctions or damage caused by exceeding the design range.

[0074] Second, in this embodiment, the connection method between the front shock absorber and the torque compensation device has been optimized:

[0075] Because turboprop engines can be affected by various load changes during operation, such as variations in flight speed, altitude, and propeller speed, these changes can cause fluctuations in the torque generated by the engine. Therefore, a hydraulic torque compensation device is typically installed on the aircraft frame. The torque compensator is mainly used to reduce torque fluctuations caused by load changes. During operation, the hydraulic torque compensation device usually needs to be connected to the front shock absorber to achieve its function of automatically adjusting the output torque.

[0076] The patent documents cited in the background do not disclose in detail how the hydraulic torque compensation device is connected to the front shock absorber.

[0077] Therefore, the applicant made the following optimizations:

[0078] like Figure 15 and Figure 16 As shown, the front shock absorber 3 includes a main mounting bracket 37. The main mounting bracket 37 has a vertical main mounting bracket through-hole 38 and a horizontal main mounting bracket through-hole 39. The central axes of the main mounting bracket through-hole 38 and the main mounting bracket through-hole 39 are arranged in a cross shape, and one end of the main mounting bracket through-hole 39 is connected to the main mounting bracket through-hole 38. The main mounting bracket 37 also has a vertical main mounting bracket through-hole 40, located at the middle position of the main mounting bracket through-hole 39, and one end of the main mounting bracket through-hole 40 is connected to the main mounting bracket through-hole 39. Figure 15 and Figure 17 As shown, when connecting the front shock absorber and the torque compensation device, one end of the connecting rod 42 with ball bearing 41 is inserted from the main mounting bracket through hole 30 into the main mounting bracket through hole 29. The other end of the connecting rod 42 is connected to the torque compensation device. Then, the bolt shank 431 of the bolt 43 is inserted from the main mounting bracket through hole 29, passes through the inner ring of the ball bearing 41 on one end of the connecting rod 42, and connects with the inner ring of the ball bearing 41 before extending into the main mounting bracket through hole 18. Then, the nut 44 is locked onto the bolt shank 431 located in the main mounting bracket through hole 138, thereby locking the bolt 43 onto the main mounting bracket 37, thus connecting the front shock absorber and the torque compensation device. Through the above connection method, this embodiment can realize the connection function between the front shock absorber and the torque compensation device. Thus, when the load changes, the torque compensator can automatically adjust the output torque, maintain the smooth operation of the engine, reduce vibration and noise levels, and thus improve flight safety and comfort.

[0079] Another problem encountered during connection is that to tighten bolt 43, nut 44 must be secured and torque applied to bolt 43, or bolt 43 must be secured and torque applied to nut 44. However, due to certain reasons, the space in the through hole 38 of the main mounting bracket is very narrow, making it impossible for operators to insert their hands or wrenches to secure nut 44 or apply torque. Therefore, in this installation condition, it is difficult to tighten the bolt, increasing workload and reducing efficiency. Therefore, in this embodiment, the applicant designed nut 44 as an elastic nut 44, the shape of which matches the shape of the through hole 38 of the main mounting bracket; such as Figures 17 to 19 As shown, during connection, the elastic nut 44 is first inserted into the main mounting bracket through hole 38 from one end. After the elastic nut 44 enters the main mounting bracket through hole 38, due to the elasticity of the elastic nut 44, it is supported in the main mounting bracket through hole 38 and will not fall out. Then, a tool such as a rod is used to push the elastic nut 44 axially in the main mounting bracket through hole 38, so that it moves to one end of the main mounting bracket through hole 39. Then, the bolt 43 is inserted into the main mounting bracket through hole 39 so that the bolt shank 431 is located at the elastic nut 44. Then, torque is applied to the bolt 43. At this time, since the shape of the elastic nut 44 matches the shape of the main mounting bracket through hole 38, the main mounting bracket through hole 38 can be used to limit the rotation of the elastic nut 44, so that when the bolt 43 rotates, the elastic nut 44 is fixed and cannot rotate with the bolt 43. Finally, the bolt 43 is locked to the main mounting bracket by the elastic nut 44. This embodiment designs an elastic nut, which is elastically supported on the inner circumference of the through hole. The through hole is then used to limit the rotation of the elastic nut, effectively allowing the elastic nut to move axially within the through hole but not rotate. During operation, the elastic nut is moved to the inserted bolt shank, and then the rotating bolt and the rotationally limited elastic nut work together to lock the bolt. This allows for convenient and quick bolt locking in confined installation spaces, reducing workload and improving efficiency.

[0080] like Figure 20As shown, the elastic nut 44 is columnar, including a left nut portion 45 and a right elastic portion 46 connected to the left nut portion 45. The outer peripheral surface shape of the columnar elastic nut 44 matches the inner peripheral surface shape of the main mounting bracket through hole 38. In this embodiment, the inner peripheral surface of the main mounting bracket through hole 38 is circular. Therefore, both the left nut portion 45 and the right elastic portion 46 are semi-circular. When the inner peripheral surface shape of the main mounting bracket through hole 38 is square or other shapes, the corresponding outer peripheral surface shape of the elastic nut 44 is also set to square or other shapes. When the elastic nut 44 is placed into the through hole 38 of the main mounting bracket, the outer peripheral surface of the right elastic part 46 is compressed by the inner peripheral surface of the through hole 38 of the main mounting bracket, causing elastic deformation. After the elastic nut 44 is placed into the through hole 38 of the main mounting bracket, the outer peripheral surface of the left nut part 45 contacts the inner peripheral surface of the through hole 38 of the main mounting bracket, while the right elastic part 46, under the action of the elastic restoring force, makes its outer peripheral surface tightly and elastically contact the inner peripheral surface of the through hole 38 of the main mounting bracket, thereby supporting the elastic nut 44 on the inner peripheral surface of the through hole 38 of the main mounting bracket and preventing it from falling out.

[0081] like Figure 21 and Figure 22 As shown, the right elastic part 46 includes a spring body 461 and a spring connector disposed on the spring body 461, through which the spring body 461 is connected to the left nut part 45. In this embodiment, the spring connector consists of an upper clip 462 disposed at the top of the spring body 461 and a lower clip 463 disposed at the bottom of the spring body 461. When connected to the left nut part 45, as... Figure 20As shown, the left nut portion 45 is engaged between the upper clip 462 and the lower clip 463, thereby connecting the left nut portion 45 and the right elastic portion 46 into one unit. This engagement structure connects the spring body and the spring connector into one unit, simplifying the assembly structure. The outer surface of the spring body 461 is the outer peripheral surface of the right elastic portion 46. The shape of the outer surface of the spring body 461 matches the shape of the inner peripheral surface of the main mounting bracket through hole 38. Since the inner peripheral surface of the main mounting bracket through hole 38 is circular in this embodiment, the outer surface of the spring body 461 is correspondingly set as an arc-shaped surface. Here, when the inner peripheral surface of the main mounting bracket through hole 38 is square, the outer surface of the spring body 461 can also be set as square. In order to support the elastic nut 44 on the inner circumferential surface of the main mounting bracket through hole 38 through the elastic deformation of the outer peripheral surface of the right elastic part 46, the size of the spring piece 461 is slightly larger than the size of the main mounting bracket through hole 38. In this embodiment, the radius of the spring piece 461 is slightly larger than the radius of the main mounting bracket through hole 38, so that when the elastic nut 44 is placed in the main mounting bracket through hole 38, the spring piece 461 can be compressed and undergo elastic deformation. After the elastic nut 44 is placed in the main mounting bracket through hole 38, under the action of the elastic restoring force, the outer surface of the spring piece 461 elastically adheres to the inner circumferential surface of the main mounting bracket through hole 38, supporting the entire elastic nut 44 in the main mounting bracket through hole 38, and preventing it from falling off. In addition, along the axial direction, an elastic deformation gap L1 is left between the spring body 461 and the left nut part 45. In this way, when the outer side of the spring body 461 is deformed by the compression of the main mounting bracket through hole 38, the elastic deformation gap L1 can ensure that the spring body 461 has sufficient deformation space when it undergoes elastic deformation.

[0082] like Figure 23 and Figure 24As shown, the left nut portion 45 includes a hollow nut seat 47 and a nut sleeve 48 connected to one side of the nut seat 47. The aforementioned elastic deformation gap L1 is located between the nut seat 47 and the spring body 461. The nut seat 47 includes a hollow seat body 471, a seat top plate 472 disposed on one side of the seat body 471, and a seat bottom plate 473 disposed on one side of the seat body 471. The other side of the seat body 471 is the outer side of the seat body 471, which is the outer peripheral surface of the left nut portion 45. The shape of the outer side of the seat body 471 matches the inner peripheral surface shape of the main mounting bracket through hole 38. Since the inner peripheral surface of the main mounting bracket through hole 38 is circular in this embodiment, the outer side of the seat body 471 is correspondingly set as an arc surface. Here, when the inner peripheral surface of the main mounting bracket through hole 38 is square, the outer side of the seat body 471 can also be set as square. The dimensions of the base 471 match the dimensions of the through hole 38 of the main mounting bracket, so that when the elastic nut 44 is placed in the through hole 38, the outer surface of the base 471 contacts the inner circumferential surface of the through hole 38. Furthermore, the matching shape of the outer surface of the base 471 with the inner circumferential surface of the through hole 38 also creates a rotation-limiting structure for the left nut portion 45 between the base 471 and the through hole 38, preventing the left nut portion 45 from rotating during bolt tightening. When the left nut portion is connected to the right elastic portion, it is engaged between the upper clip 462 and the lower clip 463, so that the top plate 472 of the base 45 contacts the upper clip 462, and the bottom plate 473 of the base 45 contacts the lower clip 463, thereby connecting the left nut portion 45 and the right elastic portion 46 into one unit.

[0083] like Figure 23 and Figure 25As shown, the nut sleeve 48 includes a sleeve body 481 and a sleeve flange 482 disposed on one end of the sleeve body 481. The sleeve body 481 and the sleeve flange 482 are integral structures. A thread 49 is provided on the inner circumferential surface of the sleeve body 481. The inner cavity 483 of the sleeve body 481 is connected to the inner cavity 474 of the seat body 471, and the inner cavity 483 of the sleeve body 481 and the inner cavity 474 of the seat body 471 are located on the same central axis. During operation, the bolt shank of the bolt extends from the inner cavity 483 into the inner cavity 474 of the seat body. An inner conical surface 50 is provided on the inner circumferential surface of the sleeve 481, near the sleeve flange 482. When the bolt shank 431 extends in and there is a slight deviation between the central axis of the bolt shank 431 and the central axis of the sleeve 481, the end of the bolt shank 431 contacts and engages with the inner conical surface 50 during the extension process. This allows the position of the elastic nut to be automatically adjusted, causing the elastic nut to move slightly axially for fine adjustment. This ensures that the central axis of the bolt shank 431 coincides with the central axis of the sleeve 481, guaranteeing that the bolt shank 431 can smoothly enter the inner cavity of the sleeve 481 and engage with the thread 49, thus ensuring smooth operation.

[0084] like Figure 24 and Figure 25As shown, in order to facilitate the connection between the nut seat 47 and the nut sleeve 48, the applicant designed a simple connection method. That is, a first stop bar 51 and a second stop bar 52 are respectively provided on the top plate 472 and the bottom plate 473 of the nut seat 47. During connection, the nut sleeve 48 is first placed on one side of the nut seat 47, and then the first stop bar 51 and the second stop bar 52 are respectively connected to the top plate 472 and the bottom plate 473 of the nut seat 47, so that one side of the sleeve flange 482 of the nut sleeve 48 contacts the seat 471 of the nut seat 47, and the first stop bar 51 and the second stop bar 52 contact the other side of the sleeve flange 482 of the nut sleeve 48. One function of the two stop rods is to connect the nut sleeve. Another function is to prevent the nut sleeve from moving axially during operation, as the bolt exerts an axial force on it. The stop rods 51 and 52 prevent this axial movement, ensuring normal operation. To simplify the connection between the stop rods and the nut seat, this embodiment has stop rod mounting holes 53 and 52 (not shown in the figure) on the top plate 472 and bottom plate 473 of the seat body, respectively. During connection, a flexible metal sheet (such as an iron sheet or steel sheet) is first rolled into stop rods 51 and 52. Then, one end of the rolled stop rod 51 and one end of the rolled stop rod 52 are inserted into the stop rod mounting holes 53 and 52, respectively. The elastic restoring force of the rolled metal sheet causes the ends of the stop rods 51 and 52 to expand and lock into the stop rod mounting holes 53 and 52, greatly simplifying the connection structure.

[0085] like Figure 26 As shown, the base 471, top plate 472, and bottom plate 473 enclose a sleeve mounting space 54 on one side of the base 471. The outer circumferential shape of the sleeve flange 482 matches the shape of the sleeve mounting space 54. During connection, when the sleeve flange 482 is placed in the sleeve mounting space 54, the sleeve flange 482 and the sleeve mounting space 54 cooperate to form a second rotation limiting structure for the nut sleeve. The outer circumferential shape of the sleeve flange 482 can be polygonal. In this embodiment, the outer circumferential shape of the sleeve flange 482 is square. Therefore, the sleeve mounting space 54 is also square. This design is mainly to prevent the nut sleeve 48 from rotating circumferentially during operation, thus facilitating the tightening of the bolt. During operation, the rotation of the nut sleeve is restricted by the rotation limiting structure 2 formed between the sleeve flange 482 and the sleeve mounting space 54, and the rotation limiting structure 1 formed between the seat and the through hole 1 restricts the rotation of the left nut part, thereby ultimately realizing the function of limiting the rotation of the elastic nut 44 by the through hole 1 38 of the main mounting bracket.

[0086] like Figure 20 and Figure 21 As shown, a spring body cavity 4611 is formed on the spring body 461. A positioning disc 55 is disposed in the spring body cavity 4611. The positioning disc 55 is connected to the spring body 461 via a connecting piece 56, and the central axis of the positioning disc 55 coincides with the central axis of the inner cavity 483 of the nut sleeve 48. Here, the central axis of the positioning disc 55 and the central axis of the inner cavity 483 of the nut sleeve 48 may not coincide; the main function is positioning. Figures 16 to 19 As shown, a positioning through hole 57 is also provided on the main mounting bracket 37 at a position relative to the second through hole 39 of the main mounting bracket. The positioning through hole 57 is connected to the first through hole 38 of the main mounting bracket, and the central axis of the positioning through hole 57 coincides with the central axis of the second through hole 39 of the main mounting bracket. Here, the central axis of the positioning through hole 57 and the central axis of the second through hole 39 of the main mounting bracket may not coincide, mainly for positioning purposes. The shape of the positioning disc 55 on the spring body 461 matches the shape of the positioning through hole 57.

[0087] During operation, when the elastic nut 44 is moved down in the through hole 38 of the main mounting bracket, it is difficult to observe whether the elastic nut 44 has moved down to the correct position due to the limited space. Therefore, a positioning through hole 57 is set opposite to the through hole 39 of the main mounting bracket. During the downward movement of the elastic nut 44, when the positioning disc 55 on the spring body 461 is engaged in the positioning through hole 57, it indicates that the elastic nut 44 has moved down to the correct position. At this time, the inner cavity 483 of the nut sleeve 48, the inner cavity 474 of the seat, and the through hole 39 of the main mounting bracket are on the same central axis. After the elastic nut 44 has moved down to the correct position, the bolt shank 431 of the bolt is then inserted through the through hole 39 of the main mounting bracket into the inner cavity 474 of the seat and the inner cavity 483 of the nut sleeve 48 for assembly. This further reduces the workload and improves work efficiency.

[0088] Third, in this embodiment, the torque compensation device has also been optimized:

[0089] Aircraft turboprop engines are mounted on engine mounts via vibration isolation devices. During aircraft operation, the engine generates torque, which, if excessive, can damage the vibration isolation devices. In such cases, counter-torque is needed to counteract the engine's torque. To counteract torque while minimizing the impact on the vibration isolation devices, a hydraulic torque compensation device mounted on the engine mount is considered to limit the reaction torque generated by the engine propeller. However, existing hydraulic torque compensation devices can only resist hydraulic axial torque. When the engine generates radial force, the piston seals of the hydraulic device are easily damaged, leading to hydraulic oil leakage.

[0090] Chinese invention patent application publication number CN104976278A, published on October 14, 2015, discloses a hydraulic torque compensation device, which includes an oil reservoir, a metal spring disposed inside the oil reservoir, a piston connected to the metal spring, a throttle valve and an overflow valve integrated inside the oil reservoir, a short conduit and a long conduit connected to the oil reservoir, a left actuating cylinder connected to the other end of the short conduit, a right actuating cylinder connected to the long conduit, a first actuating rod disposed inside the left actuating cylinder, and a second actuating rod disposed inside the right actuating cylinder.

[0091] During operation, when the engine generates radial force, the first and second actuators in the hydraulic torque compensation device described in this patent document may swing radially, which could easily damage the piston seal of the hydraulic device and lead to hydraulic oil leakage.

[0092] Therefore, the applicant made the following optimizations:

[0093] like Figure 27 As shown, a hydraulic torque compensation device in this embodiment includes: an actuator 58, a connecting pipe 59, and an accumulator 60; the actuator 58 includes a first actuator and a second actuator, and the actuator 58 has an actuating rod 61; the oil storage ends 62 of the first actuator and the second actuator are at different vertical positions, and the oil storage ends 62 of the first actuator and the second actuator are connected by the connecting pipe 59, and the accumulator 60 is connected to the connecting pipe 59; the actuating rod 61 includes a first actuating rod and a second actuating rod, both connected by two connecting rods. Rod 42 is connected to the main mounting bracket 37 of the two front shock absorbers respectively. The first actuating rod is disposed in the first actuator; the second actuating rod is disposed in the second actuator; the actuator 58 also has a piston sealing ring 63, a hydraulic chamber 64, and a radial support part 65; the piston sealing ring 63 is an annular structure that contacts the inner wall of the hydraulic chamber 64 and is disposed on the actuating rod 61; the actuating rod 61 extends upward to the outside of the hydraulic chamber 64; the radial support part 65 provides radial support for the actuating rod 61 when the actuating rod 61 moves.

[0094] It should be noted that, referring to Figure 27 and Figure 28In this embodiment, the hydraulic anti-torsion device of the engine 1 vibration reduction system is fixedly installed on the aircraft frame. The hydraulic anti-torsion device provides unidirectional axial torsion resistance, reducing the impact on the vibration isolation device while resisting torsion. The connecting pipe 59 is made of metal. Each actuator 58 has a liquid reservoir end and an air reservoir end; when the liquid reservoir end of the first actuator 58 is at the top, the liquid reservoir end of the second actuator 58 is at the bottom, providing counter-torque when the engine 1 twists. The actuator rod 61 extends upward to the outside of the hydraulic chamber 64. The actuator 58 of the hydraulic anti-torsion device also has a radial support portion 65. When the engine 1 generates radial force, the radial support portion 65 supports and limits the upward extension end of the actuator rod 61, or supports and limits both the upward extension end and the lower end of the actuator rod 61, to radially limit and support the entire actuator rod 61, preventing damage to the hydraulic piston seal caused by the actuator rod 61 driving the piston sealing ring to twist or shift. In this embodiment and subsequent embodiments, both the actuator 58 and the accumulator 60 are provided with mounting holes and fixedly mounted on the aircraft engine mounting bracket.

[0095] Specifically, refer to Figure 27 When the engine 1 generates input torque Tin, the piston sealing ring 63 and the actuator rod 61 of the left actuator 58 move upward by XC, while the piston sealing ring 63 and the actuator rod 61 of the right actuator 58 move downward by XC.

[0096] In this embodiment, the hydraulic anti-torsion device of the engine 1 vibration damping system provides anti-torque when the engine 1 is under high torque conditions; it also has a radial support 65 to provide radial support for the actuator 61, which can prevent hydraulic oil leakage caused by the radial force of the engine 1 causing the hydraulic device actuator 61 to deviate and the piston sealing ring to form a gap with the inner wall of the hydraulic chamber 64.

[0097] Furthermore, the lower end of the hydraulic chamber 64 is provided with a first limiting hole 66, and the actuating rod 61 extends downward to the outside of the hydraulic chamber 64 through the first limiting hole 66; the radial support part 65 is disposed on the hydraulic chamber 64 and / or the actuating rod 61, and when the actuating rod 61 moves, the radial support part 65 cooperates with the first limiting hole 66 to provide radial support for the actuating rod 61.

[0098] It should be noted that the first limiting hole 66 provides axial limiting and axial support for the actuating rod 61. The radial support part 65 can be: when the actuating rod 61 extends upward, a support structure is provided above the hydraulic chamber 64, and the support structure, in conjunction with the first limiting hole 66, provides radial constraint and support for the upwardly extending actuating rod 61; when the actuating rod 61 extends upward, support structures are provided above and below the actuating cylinder to radially constrain the actuating rod 61. The support structure can specifically be a support ring or a support rod, etc., and is provided on the actuating rod 61 and / or the hydraulic chamber 64.

[0099] In this embodiment, the high-pressure piston dynamic seal structure has a first limiting hole 66 for axial limiting and axial support of the actuating rod 61, and a radial support portion 65 that cooperates with the first limiting hole 66 to provide radial support for the actuating rod 61. Specifically, the radial support portion 65 can be a support structure on the actuating rod 61 or a support ring provided on the hydraulic chamber 64. This prevents hydraulic oil leakage caused by hydraulic device actuating rod 61 shifting due to radial force from the engine 1, resulting in gaps between the piston sealing ring and the inner wall of the hydraulic chamber 64.

[0100] Further, the radial support portion 65 comprises: cavities at both the upper and lower ends of the hydraulic chamber 64; a ring-shaped support structure fixedly mounted on the actuating rod 61, the ring-shaped support structure being movable within the cavities; baffles at both the upper and lower ends of the hydraulic chamber 64; the ring-shaped support structure fixedly mounted on the actuating rod 61; the baffles providing radial support for the ring-shaped support structure; a support ring fixedly mounted at the upper end of the hydraulic chamber 64; the support ring providing radial support for the actuating rod 61; or the support ring fixedly mounted at both the upper and lower ends of the hydraulic chamber 64; the support ring providing radial support for the actuating rod 61.

[0101] It should be noted that when the actuator rod 61 moves up and down, the first limiting hole 66 axially limits the actuator rod 61. At this time, the actuator rod 61 has only one support point at the first limiting hole 66. Once the engine 1 generates radial force, the actuator rod 61 is prone to twisting or shifting off the central axis, causing the piston sealing ring to shift at a corresponding angle and no longer be perpendicular to the inner wall of the hydraulic chamber 64, thus forming a gap and causing hydraulic oil leakage. The radial support part 65 is an additional support point on the upward extension end of the hydraulic rod. This additional support point cooperates with the support point at the first limiting hole 66 to provide radial support for the actuator rod 61. In other feasible embodiments, in addition to supporting the upward extension end of the hydraulic rod, the radial support part 65 can also add a support point below the first limiting hole 66 to further provide radial support for the actuator rod 61. The upper end of the hydraulic chamber 64 is provided with an upper support ring to limit and support the upward extension end of the actuator rod 61, and a lower support ring is also provided below the first limiting hole 66 of the hydraulic chamber 64 to further limit and support the actuator rod 61.

[0102] Specifically, the annular support structure is fixedly installed at the upward extension end and the lower end of the actuating rod 61. Both the upward extension end and the lower end remain outside the hydraulic cavity 64 when the actuating rod 61 moves. The outer side of the annular support structure contacts the inner wall of the cavity or a baffle, which limits the movement of the annular support structure. When the actuating rod 61 moves up and down, the first limiting hole 66 axially limits the actuating rod 61, and the upper and lower cavities or baffles of the hydraulic cavity 64 cooperate with the annular support structure to provide radial support for the actuating rod 61.

[0103] When a support ring is fixedly installed at the upper end of the hydraulic chamber 64, the support ring limits and supports the upward extension end of the actuator 61 when the actuator 61 moves. The support ring and the first limiting hole 66 cooperate to provide more stable radial support for the actuator 61.

[0104] In this embodiment, the upper support ring, the first limiting hole 66 and the lower support ring cooperate to provide radial support for the actuating rod 61.

[0105] Furthermore, the upper end of the hydraulic chamber 64 has a second limiting hole 67, and the first limiting hole 66 and the second limiting hole 67 allow the actuating rod 61 to move longitudinally; the support ring is provided at the first limiting hole 66 and the support ring is provided at the second limiting hole 67.

[0106] It should be noted that the actuating rod 61 is a hollow rod structure. The upward extension end of the actuating rod 61 passes through the second limiting hole 67 to the outside of the hydraulic chamber 64. The first limiting hole 66 and the second limiting hole 67 radially constrain the actuating rod 61. In this embodiment, the support ring is fixedly disposed inside the limiting hole. In other feasible embodiments, the support ring can be disposed on the outside of the limiting hole away from the hydraulic chamber 64. Both the first limiting hole 66 and the second limiting hole 67 are provided with annular support grooves for fixing and installing the support ring. The support ring can be made of metal, ceramic, or wear-resistant polymer material.

[0107] In this embodiment, by radially limiting the upper and lower ends of the actuator rod 61, and by setting support rings at the first limiting hole 66 and the second limiting hole 67, radial support is provided for the upper and lower ends of the actuator rod 61.

[0108] Furthermore, both the first actuating rod 61 and the second actuating rod 61 have a connecting hole 68 at their lower ends. The connecting hole 68 is connected to the engine 1 through a tie rod bearing, and the actuating rod 61 transmits the force and torque of the engine 1.

[0109] In other feasible embodiments, the connecting hole 68 can be connected to the main bracket of the front damper 3 of the engine 1 via a tie rod bearing to connect to the engine 1. The main bracket of the front damper 3 is directly mounted on the engine 1 by bolts, and the actuating rod 61 is connected to the engine 1 via the main bracket of the front damper 3.

[0110] Further, the accumulator 60 includes: an energy storage chamber 601, a spring 602, an indicator rod 603, and an accumulator piston 604; the energy storage chamber 601 has a storage end and a pressure end, the storage end being connected to the hydraulic system connecting pipe 59; the indicator rod 603 and the spring 602 are disposed at the pressure end, the indicator rod 603 is connected to the accumulator piston 604 and moves with the accumulator piston 604, and the hydraulic system pressure can be detected by detecting the position of the indicator rod 603; the spring 602 is sleeved on the indicator rod 603 and presses against the accumulator piston 604 to compensate for the hydraulic system pressure.

[0111] It should be noted that the storage end stores hydraulic oil for the hydraulic system. Initially, the accumulator 60 is full of hydraulic oil, the level is at its maximum, and the spring 602 is compressed to its maximum. If hydraulic oil leakage occurs, and the leakage is minor, the pressure applied by the spring 602 to the accumulator piston 604 can compensate for the hydraulic system pressure and ensure that the storage end of the accumulator chamber 601 and the entire hydraulic system are filled with hydraulic oil. Even with a small amount of leakage from the hydraulic anti-torsion device, it can still provide anti-torsion protection. The indicator rod 603 is connected to the accumulator piston 604. When the liquid level in the accumulator 60 changes, the accumulator piston 604 moves the indicator rod 603. The hydraulic system pressure can be detected by detecting the movement distance or position of the indicator rod 603. A certain displacement distance range or position is marked on the indicator rod 603. When this displacement distance range or position is reached, a corresponding hydraulic position indication is output. The indication may include: adding hydraulic oil, replacing the hydraulic anti-torsion device, etc.

[0112] For example, the position of the indicator rod 603 can be determined by marking an indicator area on the indicator rod 603, and the hydraulic system pressure can be determined by the indicator area pointed to by the fixed point of the accumulator 60. The movement distance of the indicator rod 603 can be detected by a displacement detection device, and the hydraulic system pressure can be determined based on the movement distance.

[0113] In this embodiment, the indicator rod 603 is connected to the accumulator piston 604 and moves with it. The hydraulic system pressure can be detected by detecting the movement distance or position of the indicator rod 603. When the hydraulic system pressure decreases, hydraulic oil leaks, and a corresponding prompt is output in a timely manner when the pressure decreases to a certain range.

[0114] Furthermore, the pressure end is provided with a through hole, the top end of the indicator rod 603 passes through the through hole, and the display length of the indicator rod 603 outside the accumulator 60 changes as the accumulator piston 604 moves.

[0115] It should be noted that the indicating length of the external indicator rod 603 of the accumulator 60 changes with the position of the accumulator piston 604; when the liquid level drops, the indicating length decreases. In one feasible embodiment, the indicator rod 603 can point to different positions depending on the fixed position of the through hole.

[0116] In this embodiment, the pressure within the hydraulic system can be obtained by detecting the change in the length of the indicator rod 603 outside the accumulator through-hole 605. In other feasible embodiments, the accumulator 60 can adopt a viewing window with fixed point markings, and the indicator rod 603 has observable length scale markings inside the accumulator cavity 601. The pressure within the hydraulic system can be detected by the scale changes at the fixed points.

[0117] In other feasible embodiments, the indicator rod 603 and the accumulator piston 604 can be set separately and connected by a connection structure, such as a threaded connection or a key connection.

[0118] Furthermore, the indicator rod 603 is divided into indicator areas, which include a high hydraulic pressure area, a medium hydraulic pressure area, and a low hydraulic pressure area; as the indicator rod 603 moves, the accumulator 60 can indicate different current indicator areas to display the hydraulic system pressure of the current indicator area.

[0119] It should be noted that the high hydraulic pressure area, medium hydraulic pressure area, and low hydraulic pressure area can be distinguished by color. The current hydraulic system pressure can be displayed by pointing to different indicator areas using fixed points on the accumulator 60. These fixed points can be the aforementioned accumulator through-hole 605, the fixed point of the accumulator 60's viewing window, etc.

[0120] In this embodiment, the liquid level of the accumulator 60 is visualized by setting an indicator rod 603, which can intuitively determine the pressure of the hydraulic system and detect oil leakage in the hydraulic system in a timely manner.

[0121] In other feasible embodiments, the hydraulic system accumulator 60 is also provided with a displacement detection device to measure the displacement of the indicator rod 603.

[0122] It should be noted that in this embodiment, the indicator rod 603 is directly connected to the hydraulic system piston. The displacement of the indicator rod 603 is directly measured by the displacement detection device, which can detect the hydraulic system pressure and obtain the hydraulic system oil leakage status based on the system pressure.

[0123] In this embodiment and the above embodiments, the accumulator piston 604 has an annular groove. The annular groove is disposed on the contact surface between the accumulator piston 604 and the inner wall of the energy storage chamber 601. A sealing ring is installed in the annular groove to seal and fit the inner wall of the energy storage chamber 601, which can better maintain the sealing of the hydraulic system and prevent hydraulic oil leakage.

[0124] Furthermore, a throttling orifice 69 is provided at the connection between the accumulator 60 and the hydraulic system connecting pipe 59.

[0125] In this embodiment, the accumulator 60 is connected to the connecting pipe 59 through the throttling orifice 69 to slow down the flow rate of the accumulator 60 and prevent the accumulator 60 from being impacted by excessive pressure changes in the hydraulic system.

[0126] Based on the above embodiments, this application also provides a method for detecting the pressure of a hydraulic system accumulator, applied to the hydraulic system accumulator described above, the method comprising:

[0127] Step 10: Monitor the area indicated by the indicator rod to monitor the accumulator level;

[0128] Step 20: Output the corresponding accumulator pressure prompt based on the accumulator liquid level.

[0129] It should be noted that the accumulator's indicator rod is divided into multiple indicator zones, each representing a different accumulator fluid level. A decrease in the accumulator fluid level reduces the pressure within the accumulator, leading to hydraulic oil leakage in the hydraulic system. While the hydraulic system can still provide anti-torsion protection during minor leaks, excessive leakage necessitates timely replacement of the anti-torsion device. In this embodiment, the accumulator pressure is monitored by controlling the accumulator fluid level.

[0130] Furthermore, the indicator area of ​​the indicator rod includes a high liquid level area, a medium liquid level area, and a low liquid level area of ​​the accumulator;

[0131] Step 20 above, which outputs a corresponding accumulator pressure indication based on the accumulator liquid level, includes:

[0132] Step 201: If the area indicated by the indicator rod is detected to be the high hydraulic pressure area of ​​the accumulator, then continue monitoring;

[0133] Step 202: If the area indicated by the indicator rod is detected to be the hydraulic area in the accumulator, a prompt will be made indicating that the output pressure has decreased and fluid needs to be replenished.

[0134] Step 203: If the indicator rod is detected to be in the low hydraulic pressure area of ​​the accumulator, the output pressure is insufficient and the hydraulic system needs to be replaced.

[0135] In this embodiment, the indicator areas of the indicator rod are pre-calibrated based on experimental measurements. Each indicator area represents a different liquid level in the accumulator and a different hydraulic range in the hydraulic system. The hydraulic system pressure can be detected by detecting the indicator areas of the indicator rod. When the hydraulic system pressure decreases, hydraulic oil leaks; when the pressure drops to the calibrated range, a corresponding prompt is output in a timely manner.

[0136] In summary, this invention optimizes the connection method between the rear and front vibration dampers and the torque compensation device, as well as the torque compensation device itself. This further improves the product's performance and enhances its practicality in propeller aircraft, giving it better application prospects. By placing the main bolt between the two rubber stacks of rubber assembly two and rubber assembly one, a single main bolt can be used to press rubber assembly two and rubber assembly one against the bottom and top surfaces of the main support assembly, pre-compressing the rubber bodies in rubber assembly two and rubber assembly one. Compared to existing technologies, this reduces the number of connecting bolts, simplifies the pre-compression structure of the rubber assemblies, simplifies the installation process, and reduces the weight of the entire rear vibration damping device, meeting the requirements of lightweight design. Furthermore, this design also reduces the area of ​​the third metal frame in existing technologies, further reducing the weight of the entire rear vibration damping device. By designing the values ​​of gaps H1 and H2, precise control is achieved over the pre-compression of the rubber components in rubber assembly one and two. After the bolts and nuts reach the designed tightening torque, the bushings create a rigid metal limit to ensure the rubber remains in its designed compression state, preventing the rubber components from loosening under engine load conditions. When subjected to excessive impact or vibration, a rigid limiting structure is formed through the contact between the outer circumferential surfaces of bushing one and two and the inner circumferential surface of through hole three. This limits the deformation of the shock absorber under excessive impact or vibration, protecting both the shock absorber and the engine from damage and ensuring the shock absorber operates within its predetermined stroke range, avoiding malfunctions or damage caused by exceeding the design limits. Through optimized connection methods, this invention enables the connection between the front shock absorber and the torque compensation device. This allows the torque compensator to automatically adjust its output torque when the load changes, maintaining stable engine operation, reducing vibration and noise levels, and thus improving flight safety and comfort. By designing the nut as an elastic nut, its elastic support rests on the inner circumference of the through hole. The through hole then acts as a limit for the rotation of the elastic nut, effectively preventing axial movement within the through hole. During operation, the elastic nut is moved to the inserted bolt shank, and then the rotating bolt engages with the limiting elastic nut for locking. This allows for convenient and quick bolt tightening in confined installation spaces, reducing workload and increasing efficiency. Furthermore, by using a positioning disc that mates with the positioning through hole to form a positioning structure, workload is further reduced, and efficiency is improved. An optimized torque compensation device limits the reaction torque generated by the engine propeller. The device also features a radial support section that provides radial support to the actuator rod, and this radial support section engages with the first limiting hole to provide radial support to the actuator rod. Specifically, the radial support section can be a support structure on the actuator rod or a support ring on the hydraulic chamber.It can prevent hydraulic oil leakage caused by the displacement of the hydraulic device actuator rod due to the radial force of the engine, and the gap between the piston sealing ring and the cylinder wall.

[0137] In the embodiments, "multiple" refers to "two or more". The above embodiments are for illustrative purposes only and are not intended to limit the invention. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions should also fall within the protection scope of the invention, which is defined by the claims.

Claims

1. A method for arranging a turboprop engine, wherein the turboprop engine is arranged on an aircraft frame via a vibration damping system, the vibration damping system comprising: Near the front of the engine, there are two front side dampers and one front upper damper installed between the aircraft frame and the turboprop engine. Near the rear of the engine, two rear shock absorbers are installed between the aircraft frame and the turboprop engine; a torque compensation device is also installed on the aircraft frame at the front of the engine, and the torque compensation device is connected to the two front shock absorbers; the two front shock absorbers and the two rear shock absorbers are respectively located on both sides of the turboprop engine, and the upper front shock absorber is located at the top of the turboprop engine. The turboprop engine arrangement method includes optimizing the pre-compression method of the rubber assembly in the rear shock absorbers; the rear shock absorbers also include a main support assembly and a mounting bracket assembly disposed on one side of the main support assembly; the rubber assembly... The component includes rubber component one and rubber component two. The main support assembly is located between rubber component one and rubber component two. During installation, the main bolt passes through the middle position of rubber component two, the middle position of the main support assembly and rubber component one in sequence, and is then locked with a nut, thereby pressing rubber component two and rubber component one onto the bottom and top surfaces of the main support assembly. This results in the rubber bodies in rubber component two and rubber component one being in a pre-compressed state. The main bolt passing through the main support assembly is connected to one end of the mounting bracket assembly through ball bearing one. The other side of the main support assembly is connected to the aircraft frame through screw one with ball bearing and screw two with ball bearing. Both rubber component 2 and rubber component 1 include a top plate, a bottom plate 1 and a bottom plate 2. The rubber body in both rubber component 2 and rubber component 1 includes a rubber stack 1 and a rubber stack 2. The bottom plate 1 is vulcanized and bonded to the top plate through the rubber stack 1, and the bottom plate 2 is vulcanized and bonded to the top plate through the rubber stack 2. The rubber stack 1 and the rubber stack 2 are located at both ends of the top plate, and a through hole is opened in the middle of the top plate. During installation, the main bolt passes through the through hole of rubber component 2, the through hole of the main support assembly, and the through hole of rubber component 1 in sequence and is then locked with the nut. After locking, the bottom plate 1 and bottom plate 2 of rubber component 2 contact the bottom surface of the main support assembly, and the bottom plate 1 and bottom plate 2 of rubber component 1 contact the top surface of the main support assembly. Two bushings are fitted around the outside of the main bolt; bushing one is located between the top plate of rubber assembly one and ball bearing one, and bushing two is located between the top plate of rubber assembly two and ball bearing one. Before pre-compression, one end of bushing one is in contact with the top plate of rubber assembly one, and the other end of bushing one has a gap H1 between it and the end face of the inner ring of ball bearing one. One end of bushing two is in contact with the top plate of rubber assembly two, and the other end of bushing two has a gap H2 between it and the end face of the inner ring of ball bearing one. After the main bolt is tightened for pre-compression, both gaps H1 and H2 are zero. By designing the values ​​of gaps H1 and H2, the pre-compression of the rubber bodies in rubber component two and rubber component one can be controlled.

2. The turboprop engine arrangement method according to claim 1, characterized in that: The turboprop engine arrangement method also includes optimizing the rigid limiting structure of the rubber component in the rear shock absorber. The mounting bracket assembly includes a mounting bracket frame with a ball bearing mounting hole at one end. The main support assembly includes a main support frame with a through hole three at the middle position. When one end of the mounting bracket assembly is inserted into one side of the main support assembly, the central axis of the ball bearing mounting hole coincides with the central axis of the through hole three. After installation, the ball bearing is positioned between the outside of the main bolt and the ball bearing mounting hole, so that the main bolt passing through the main support assembly is connected to one end of the mounting bracket assembly through the ball bearing. Both bushing one and bushing two are located in through hole three, and there is a gap H4 between the outer peripheral surface of bushing one and the inner peripheral surface of through hole three, and a gap H5 between the outer peripheral surface of bushing two and the inner peripheral surface of through hole three. When subjected to excessive impact or vibration, a rigid limiting structure is formed through the contact between the outer circumferential surfaces of bushing one and bushing two and the inner circumferential surface of through hole three.

3. The turboprop engine arrangement method according to claim 2, characterized in that: The turboprop engine arrangement method also includes optimizing the installation method between the rear shock absorber and the aircraft frame. The main support assembly is provided with a ball bearing second mounting hole and a ball bearing third mounting hole. The ball bearing in the screw with ball bearing is ball bearing second, and the ball bearing in the screw with ball bearing is ball bearing third. After installation, ball bearing 2 is positioned between one end of screw 1 and the mounting hole of ball bearing 2, so that one end of screw 1 is connected to the main support assembly through ball bearing 2. Ball bearing 3 is positioned between one end of screw 2 and the mounting hole of ball bearing 3, so that one end of screw 2 is connected to the main support assembly through ball bearing 3. The other ends of screw 1 and screw 2 are both connected to the aircraft frame.

4. The turboprop engine arrangement method according to claim 3, characterized in that: Mounting arm one and mounting arm two are provided on the aircraft frame. Mounting through hole one is provided at one end of mounting arm one, and mounting through hole two is provided at one end of mounting arm two. During connection, the other end of screw one is passed through mounting through hole one and locked with mounting nut one, and the other end of screw two is passed through mounting through hole two and locked with mounting nut two, so that the other ends of screw one and screw two are connected to the aircraft frame.

5. The turboprop engine arrangement method according to claim 4, characterized in that: The main support assembly also includes a rotating arm. A connecting arm and a hanging lug are provided on one side of the main support frame. The connecting arm and the hanging lug are integral with the main support frame. One end of the rotating arm is hinged to the hanging lug. A second ball bearing mounting hole is provided on the connecting arm, and a third ball bearing mounting hole is provided on the other end of the rotating arm. During connection, first connect the first screw with ball bearing to the first mounting arm. After connection, adjust the installation position of the second screw with ball bearing according to the actual position of the second mounting through hole, and then connect the second screw with ball bearing to the second mounting arm.

6. The turboprop engine arrangement method according to any one of claims 1 to 5, characterized in that: The turboprop engine arrangement method includes optimization of the hydraulic anti-torsion device of the engine vibration damping system. The hydraulic anti-torsion device includes: an actuator, a connecting pipe, and an accumulator. The actuator includes a first actuator and a second actuator, each having an actuating rod. The oil storage ends of the first actuator and the second actuator are at different vertical positions and are connected by the connecting pipe. The accumulator is connected to the connecting pipe. The actuating rod includes a first actuating rod and a second actuating rod, both connected to the engine. The first actuating rod is located within the first actuator; the second actuating rod is located within the second actuator. The optimization of the hydraulic anti-torsion device of the engine vibration reduction system involves designing the actuator as a piston sealing ring, a hydraulic chamber, and a radial support portion; the piston sealing ring is an annular structure that contacts the inner wall of the hydraulic chamber and is disposed on the actuating rod; the actuating rod extends upward to the outside of the hydraulic chamber; the radial support portion provides radial support for the actuating rod when it moves.

7. The turboprop engine arrangement method according to claim 6, characterized in that: The accumulator includes: an energy storage chamber, a spring, an indicator rod, and an accumulator piston; the energy storage chamber has a storage end and a pressure end, the storage end being connected to a hydraulic system connecting pipe; the indicator rod and the spring are disposed at the pressure end, the indicator rod is connected to the accumulator piston and moves with the accumulator piston, and the hydraulic system pressure can be detected by detecting the position of the indicator rod; the spring is sleeved on the indicator rod and presses against the accumulator piston to compensate for the hydraulic system pressure.

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