Pre-compression method for rubber assembly in rear shock absorber of turboprop engine

Abstract

The invention discloses a pre-compression method for rubber assemblies in a rear-side shock absorber of a turboprop engine, the rear-side shock absorber further comprises a main support assembly, the rubber assemblies comprise a first rubber assembly and a second rubber assembly, the main support assembly is arranged between the first rubber assembly and the second rubber assembly, and during installation, the main support assembly is arranged between the first rubber assembly and the second rubber assembly. A main bolt sequentially penetrates through the middle position of the second rubber assembly, the main support assembly and the middle position of the first rubber assembly and then is locked with a nut, so that the second rubber assembly and the first rubber assembly are tightly pressed on the bottom face and the top face of the main support assembly, and rubber bodies in the second rubber assembly and the first rubber assembly are in a pre-compressed state. The pre-compression structure of the rubber assembly is simplified, the installation steps are simplified, the weight of the whole rear side damping device is reduced, and the requirement for lightweight design is met.

Description

Technical Field

[0001] The present invention relates to a pre-compression method for a rubber component in a rear shock absorber, and more particularly to a pre-compression method for a rubber component in a rear shock absorber of a turboprop engine, belonging to the technical field of turboprop engine vibration reduction. Background Art

[0002] A turboprop engine is an engine that combines jet thrust and propeller thrust. It combines the characteristics of a jet engine and a propeller engine and has better performance in aspects such as low-speed flight and short takeoff and landing. Therefore, turboprop engines are widely used in aircraft such as small airplanes, helicopters, and unmanned aerial vehicles.

[0003] When a turboprop engine operates, due to the rotation of the propeller, large vibrations will be generated. Therefore, the vibration problem of a turboprop engine may be more prominent compared to other types of aeroengines. Vibration will have an adverse impact on the working performance of the engine itself, may cause wear and fatigue of engine components, thereby shortening its service life. At the same time, vibration will also cause damage to the aircraft airframe structure, such as inducing structural fatigue cracks, etc., and thus endanger the life and safety of the fuselage. Therefore, shock absorbers are generally installed between the engine and the aircraft frame to absorb and isolate vibration energy.

[0004] Along the length of the turboprop engine, the side close to the turboprop is set as the front side of the engine, and the opposite side is the rear side of the engine. After installing the shock absorber, according to its position relative to the engine, the shock absorber can be divided into a front shock absorber, a front upper shock absorber, and a rear shock absorber. Chinese Patent Application Publication No. CN116039935A, published on May 2, 2023, discloses a vibration reduction installation system for a large turboprop passenger aircraft engine, which includes: a turboprop engine having a front mounting surface on the side close to the propeller and a rear mounting surface on the side close to the turbine combustor. There are two mounting points and three front mounting joints on the front mounting surface, and two rear mounting joints on the rear mounting surface. Among them, a mechanical or hydraulic torque compensation device is installed at the two mounting points; the three front mounting joints include a first front mounting joint and two second front mounting joints. The first front mounting joint is located at the vertex of the front mounting surface, and the two second front mounting joints are symmetrically arranged on the left and right along the engine longitudinal vertical plane. A front upper shock absorption device is installed at the first front mounting joint, and a front shock absorption device is installed at the second front mounting joint; the two rear mounting joints are symmetrically arranged on the left and right along the engine longitudinal vertical plane, and a rear shock absorption device is installed at the two rear mounting joints.

[0005] A third rubber pile is provided in the rear side vibration reduction device of the patent document, and after installation, the third rubber pile is in a pre-compressed state. In the patent document, the third rubber pile is pre-compressed by a third connecting bolt and a fourth connecting bolt.

[0006] However, using two connecting bolts to pre-compress the rubber pile has problems such as complex structure and cumbersome installation steps. In addition, using two connecting bolts to pre-compress the rubber pile also increases the weight of the entire rear vibration damping device. In the application scenario of aircraft engines, an overly heavy rear vibration damping device is extremely detrimental to the flight of the aircraft.

[0007] In summary, how to design a pre-compression method for the rubber component in the rear shock absorber of a turboprop engine so that it can simplify the pre-compression structure of the rubber component, simplify the installation steps and reduce the weight of the entire rear shock absorber to meet the requirements of lightweight design is a technical problem that needs to be solved urgently. Summary of the invention

[0008] The technical problem to be solved by the present invention is to address the defects existing in the prior art and provide a pre-compression method for a rubber component in a rear shock absorber of a turboprop engine, which simplifies the pre-compression structure of the rubber component, simplifies the installation steps and reduces the weight of the entire rear shock absorber, thereby meeting the requirements of lightweight design.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for pre-compressing a rubber component in a rear shock absorber of a turboprop engine, wherein the rear shock absorber also includes a main bracket assembly, and the rubber component includes a rubber component one and a rubber component two. The main bracket assembly is arranged between the rubber component one and the rubber component two. During installation, a main bolt is sequentially passed through the middle position of the rubber component two, the middle position of the main bracket assembly and the rubber component one, and then locked with a nut, thereby pressing the rubber component two and the rubber component one against the bottom and top surfaces of the main bracket assembly, so that the rubber bodies in the rubber component two and the rubber component one are in a pre-compressed state.

[0010] Preferably, the rubber component 2 and the rubber component 1 both include a top plate, a bottom plate 1 and a bottom plate 2, the rubber bodies in the rubber component 2 and the rubber component 1 both include a rubber pile 1 and a rubber pile 2, the bottom plate 1 is vulcanized and bonded to the top plate through the rubber pile 1, the bottom plate 2 is vulcanized and bonded to the top plate through the rubber pile 2, the rubber pile 1 and the rubber pile 2 are respectively located at the two 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 main bracket component 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 are in contact with the bottom surface of the main bracket component, and the bottom plate 1 and bottom plate 2 of rubber component 1 are in contact with the top surface of the main bracket component.

[0011] Preferably, the main bolt passing through the main support assembly is connected in cooperation with one end of the mounting frame assembly through a first ball bearing. A first sleeve and a second sleeve are also sleeved outside the main bolt. The first sleeve is located between the top plate of the first rubber assembly and the first ball bearing, and the second sleeve is located between the top plate of the second rubber assembly and the first ball bearing. Before pre-compression, one end of the first sleeve contacts the top plate of the first rubber assembly, and a gap H1 is left between the other end of the first sleeve and the end face of the inner ring of the first ball bearing. One end of the second sleeve contacts the top plate of the second rubber assembly, and a gap H2 is left between the other end of the second sleeve and the other end face of the inner ring of the first ball bearing. After the main bolt is tightened for pre-compression, both the gap H1 and the gap H2 become zero. By designing the values of the gap H1 and the gap H2, the pre-compression amount of the rubber bodies in the second rubber assembly and the first rubber assembly is controlled.

[0012] Preferably, flanges are provided on the outer peripheral surfaces of one ends of the first sleeve and the second sleeve, and counterbores are provided on the top plates of the first rubber assembly and the second rubber assembly. When one ends of the first sleeve and the second sleeve contact the top plate, the one ends of the first sleeve and the second sleeve are respectively inserted into the counterbores on the top plates of the first rubber assembly and the second rubber assembly, and the flanges on the one ends of the first sleeve and the second sleeve are respectively in contact with the top plates of the first rubber assembly and the second rubber assembly. At this time, gaps H3 are left between the one ends of the first sleeve and the second sleeve and the bottom surfaces of the counterbores on the top plates of the first rubber assembly and the second rubber assembly.

[0013] Preferably, the main support assembly includes a main support frame body. A first through hole and a second through hole are formed in the main support frame body. First positioning protrusions and second positioning protrusions are respectively provided on the bottom plates of the second rubber assembly and the first rubber assembly. The shapes of the first positioning protrusions and the second positioning protrusions match the first through hole and the second through hole. During installation, the first positioning protrusions and the second positioning protrusions of the first rubber assembly are respectively inserted into one end of the first through hole and one end of the second through hole on the main support frame body, and the first positioning protrusions and the second positioning protrusions of the second rubber assembly are respectively inserted into the other end of the first through hole and the other end of the second through hole on the main support frame body, so that the bottom plates of the second rubber assembly are in contact with the bottom surface of the main support assembly, and the bottom plates of the first rubber assembly are in contact with the top surface of the main support assembly.

[0014] Preferably, the rear shock absorber further includes a mounting frame assembly. The mounting frame assembly is arranged on one side of the main support assembly. One end of the mounting frame assembly is inserted into the main support assembly, and the main bolt passing through the main support assembly is connected in cooperation with one end of the mounting frame assembly through a first ball bearing.

[0015] Preferably, the mounting frame assembly includes a mounting frame body. A first ball bearing mounting hole is provided at one end of the mounting frame body. A third through hole is also formed on the main support frame body at a position between the first through hole and the second through hole. After one end of the mounting frame assembly is inserted into one side of the main support assembly, the central axis of the first ball bearing mounting hole coincides with the central axis of the third through hole. After installation, the first ball bearing is arranged at a position between the rod body of the main bolt and the first ball bearing mounting hole, so that the main bolt passing through the main support assembly is cooperatively connected with one end of the mounting frame assembly through the first ball bearing.

[0016] Preferably, the other end of the mounting frame assembly is connected to the turboprop engine, and the other side of the main support assembly is connected to the aircraft frame through a first screw rod with a ball bearing and a second screw rod with a ball bearing.

[0017] The beneficial effects of the present invention are as follows: In the present invention, the connection position of the main bolt is set between the two rubber stacks of the second rubber component and the first rubber component. In this way, as long as a main bolt is used to press the second rubber component and the first rubber component against the bottom surface and the top surface of the main support assembly, the rubber bodies in the second rubber component and the first rubber component can be pre-compressed. Therefore, compared with the prior art, the connection structure of one connecting bolt is reduced, the pre-compression structure of the rubber component is simplified, the installation steps are simplified, and the weight of the entire rear shock absorber is reduced, meeting the requirements of lightweight design. In addition, such a setting also reduces the area of the third metal skeleton in the prior art, further reducing the weight of the entire rear shock absorber. By designing the cooperation of the positioning protrusion and the through hole, the positions of the second rubber component and the first rubber component when pressed against the bottom surface and the top surface of the main support assembly are positioned, which can further improve the assembly accuracy and assembly speed of the rear shock absorber. In addition, the weight of the main support frame body can also be reduced by the provided first through hole and second through hole, further meeting the requirements of lightweight design. By designing the values of the gap H1 and the gap H2, the pre-compression amount of the rubber bodies in the second rubber component and the first rubber component can be accurately controlled. After the bolt and nut reach the designed tightening torque, the sleeve generates metal rigid limit to ensure the designed compression state of the rubber, ensuring that the rubber parts do not loosen under the engine load condition of the rear shock absorber. Description of the Drawings

[0018] Figure 1 Is the pre-compression method in the prior art; Figure 2 Is the three-dimensional structure schematic diagram of the rear shock absorber in the embodiment of the present invention; Figure 3 Is the exploded decomposition structure schematic diagram of the rear shock absorber in the embodiment of the present invention; Figure 4 Schematic axial sectional view of the rear shock absorber in an embodiment of the present invention; Figure 5 Schematic three-dimensional structure of Rubber Component 1 in an embodiment of the present invention Figure 1 ; Figure 6 Schematic top view of the rear shock absorber in an embodiment of the present invention; Figure 7 Schematic three-dimensional structure of the main bracket assembly in an embodiment of the present invention; Figure 8 Schematic three-dimensional structure of Rubber Component 1 in an embodiment of the present invention Figure 2 ; Figure 9 Schematic three-dimensional structure of the mounting bracket assembly in an embodiment of the present invention; Figure 10 is Figure 4 Schematic partial axial sectional view at the main bolt in; Figure 11 is Figure 10 Enlarged structure diagram of part A in; Figure 12 is Figure 10 Enlarged structure diagram of part B in; In the figure: 1. Third connecting bolt, 2. Fourth connecting bolt, 3. Third metal skeleton, 4. Rubber body, 5. Rubber Component 1, 6. Rubber Component 2, 7. Main bracket assembly, 711. Main bracket frame, 712. First through hole, 713. Second through hole, 714. Third through hole, 715. Ball bearing two mounting hole, 716. Ball bearing three mounting hole, 8. Mounting bracket assembly, 811. Mounting bracket frame, 812. Ball bearing one mounting hole, 9. Main bolt, 10. Nut, 11. Ball bearing one, 111. Inner ring, 12. First screw rod, 13. Second screw rod, 14. Top plate, 141. Counterbore, 15. First bottom plate, 16. Second bottom plate, 17. First rubber stack, 18. Second rubber stack, 19. Through hole, 20. First positioning protrusion, 21. Second positioning protrusion, 22. Screw, 23. Ball bearing two, 24. Ball bearing three, 25. First bushing, 26. Second bushing, 27. Flange. Detailed implementation manners

[0019] The technical solutions of the present invention will be further elaborated in detail below with reference to the accompanying drawings and specific embodiments.

[0020] In the patent documents of the prior art mentioned in the background art, such as Figure 1As shown, the third metal skeleton 3 on both sides of the rubber stack is clamped by the third connecting bolt 1 and the fourth connecting bolt 2, so as to pre-compress the two rubber bodies 4 in the rubber stack. After further studying the positional distribution relationship between the third rubber stack and the two connecting bolts, the applicant found that the third connecting bolt 1 and the fourth connecting bolt 2 are respectively located on both sides of the two rubber bodies 4. In this positional distribution relationship, if any one of the connecting bolts is reduced, one side of the rubber body 4 will be compressed, and the other side will be in a loose state where it cannot be tightly pressed. Therefore, in this positional distribution relationship, two connecting bolts must be used to pre-compress the rubber body. As a result, the above-mentioned problems such as complex structure, cumbersome installation steps, and increased weight of the entire rear shock absorber device are caused.

[0021] Therefore, the applicant made further improvements: Embodiment: As Figures 2 to 4 shown, the rear shock absorber in this embodiment includes a first rubber component 5, a second rubber component 6, a main bracket component 7 disposed between the first rubber component 5 and the second rubber component 6, and a mounting frame component 8 disposed on one side of the main bracket component 7. One end of the mounting frame component 8 is inserted into the main bracket component 7. The main bolt 9 sequentially passes through the second rubber component 6, the main bracket component 7, and the first rubber component 5 and is locked with the nut 10, so as to press the second rubber component 6 and the first rubber component 5 against the bottom surface and the top surface of the main bracket component 7, making the rubber bodies in the second rubber component 6 and the first rubber component 5 in a pre-compressed state. The main bolt 9 passing through the main bracket component 7 is connected with one end of the mounting frame component 8 through a first ball bearing 11. The other end of the mounting frame component 8 is connected to a turboprop engine (not shown in the figure), and the other side of the main bracket component 7 is connected to an aircraft frame (not shown in the figure) through a first screw rod 12 with a ball bearing and a second screw rod 13 with a ball bearing. By installing the above-mentioned rear shock absorber between the turboprop engine and the aircraft frame to absorb and isolate vibration energy, the service life of the turboprop engine is improved, and the safety of the aircraft body is ensured.

[0022] The structures of the second rubber component 6 and the first rubber component 5 are the same. Taking the first rubber component 5 as an example, as Figure 5As shown, the first rubber component 5 includes a top plate 14, a first bottom plate 15, and a second bottom plate 16. The rubber body includes a first rubber stack 17 and a second rubber stack 18. The first bottom plate 15 is vulcanized and bonded to the top plate 14 through the first rubber stack 17, and the second bottom plate 16 is vulcanized and bonded to the top plate 14 through the second rubber stack 18. The first rubber stack 17 and the second rubber stack 18 are respectively located at both ends of the top plate 14, and a through hole 19 is formed in the middle position of the top plate 14. When installing, the main bolt 9 sequentially passes through the through hole 19 of the second rubber component 6, the main bracket component 7, and the through hole 19 of the first rubber component 5 and is then locked with the nut 10. After locking, the first bottom plate 15 and the second bottom plate 16 of the second rubber component 6 are in contact with the bottom surface of the main bracket component 7, and the first bottom plate 15 and the second bottom plate 16 of the first rubber component 5 are in contact with the top surface of the main bracket component 7. As Figure 6 shown, it can be seen that in this embodiment, the connection position of the main bolt 9 is set between the two rubber stacks of the second rubber component 6 and the first rubber component 5. In this way, as long as the second rubber component 6 and the first rubber component 5 are pressed against the bottom surface and the top surface of the main bracket component 7 by using one main bolt 9, the rubber bodies in the second rubber component 6 and the first rubber component 5 can be pre-compressed. Thus, compared with the prior art, the connection structure of one connecting bolt is reduced, the pre-compression structure of the rubber component is simplified, the installation steps are simplified, and the weight of the entire rear shock absorber is reduced, meeting the requirements of lightweight design. In addition, with such a setting, the area of the third metal skeleton (i.e., the top plate in this embodiment) in the prior art is also reduced, further reducing the weight of the entire rear shock absorber.

[0023] As Figure 7 and Figure 8As shown, the main support assembly 7 includes a main support frame 711. A first through hole 712 and a second through hole 713 are formed in the main support frame 711. On the bottom plates 15 and 16 of the second rubber assembly 6 and the first rubber assembly 5 respectively, a first positioning protrusion 20 and a second positioning protrusion 21 are provided. The shapes of the first positioning protrusion 20 and the second positioning protrusion 21 match the first through hole 712 and the second through hole 713. When the second rubber assembly 6 and the first rubber assembly 5 are pressed against the bottom surface and the top surface of the main support assembly 7, the first positioning protrusion 20 and the second positioning protrusion 21 of the first rubber assembly 5 are respectively inserted into one ends of the first through hole 712 and the second through hole 713 on the main support frame 711, and the first positioning protrusion 20 and the second positioning protrusion 21 of the second rubber assembly 6 are respectively inserted into the other ends of the first through hole 712 and the second through hole 713 on the main support frame 711, so as to position the positions of the second rubber assembly 6 and the first rubber assembly 5 when they are pressed against the bottom surface and the top surface of the main support assembly 7, which can further improve the assembly accuracy and assembly speed of the rear shock absorber; in addition, the weight of the main support frame can also be reduced by the formed first through hole and second through hole, thus further meeting the requirements of lightweight design.

[0024] As Figure 7 and Figure 9 shown, the mounting frame assembly 8 includes a mounting frame body 811. A first ball bearing mounting hole 812 is provided at one end of the mounting frame body 811. A third through hole 714 is also formed in the main support frame 711 at a position between the first through hole 712 and the second through hole 713; As Figure 4 shown, when one end of the mounting frame assembly 8 is inserted into one side of the main support assembly 7, the central axis of the first ball bearing mounting hole 812 coincides with the central axis of the third through hole 714; after installation, the first ball bearing 11 is arranged at a position between the rod body of the main bolt 9 passing through the main support assembly 7 and the first ball bearing mounting hole 812, so that the main bolt 9 passing through the main support assembly 7 is in fit connection with one end of the mounting frame assembly 8 through the first ball bearing 11. As Figure 9 shown, the other end of the mounting frame body 811 is connected to a turboprop engine (not shown in the figure) by screws 22.

[0025] As Figure 7As shown, a second ball bearing mounting hole 715 and a third ball bearing mounting hole 716 are provided on the other side of the main support assembly 7. The ball bearing in the screw rod one 12 with a ball bearing is the second ball bearing 23, and the ball bearing in the screw rod two 13 with a ball bearing is the third ball bearing 24. After installation, the second ball bearing 23 is arranged at the position between one end of the screw rod one 12 and the second ball bearing mounting hole 715, so that one end of the screw rod one 12 is cooperatively connected with the other side of the main support assembly 7 through the second ball bearing 23. The third ball bearing 24 is arranged at the position between one end of the screw rod two 13 and the third ball bearing mounting hole 716, so that one end of the screw rod two 13 is cooperatively connected with the other side of the main support assembly 7 through the third ball bearing 24. The other ends of the screw rod one 12 and the screw rod two 13 are both connected to an aircraft frame (not shown in the figure). Thus, through the above structure, the other side of the main support assembly 7 is connected to the aircraft frame (not shown in the figure) through the screw rod one 12 with a ball bearing and the screw rod two 13 with a ball bearing.

[0026] In order to further precisely control the pre-compression amount of the rubber bodies in the second rubber assembly and the first rubber assembly, the applicant has made further improvements. For example, Figure 10 and Figure 11 As shown, a first bushing 25 and a second bushing 26 are also sleeved outside the main bolt 9. The first bushing 25 is located at the position between the top plate 14 of the first rubber assembly 5 and the first ball bearing 11. The second bushing 26 is located at the position between the top plate 14 of the second rubber assembly 6 and the first ball bearing 11. Before pre-compression, one end of the first bushing 25 contacts the top plate 14 of the first rubber assembly 5, and a gap H1 is left between the other end of the first bushing 25 and one end face of the inner ring 111 of the first ball bearing 11. One end of the second bushing 26 contacts the top plate 14 of the second rubber assembly 6, and a gap H2 is left between the other end of the second bushing 26 and the other end face of the inner ring 111 of the first ball bearing 11. After the main bolt 9 is tightened for pre-compression, both the gap H1 and the gap H2 are zero, that is, the other end of the first bushing 25 contacts one end face of the inner ring 111 of the first ball bearing 11, and the other end of the second bushing 26 contacts the other end face of the inner ring 111 of the first ball bearing 11. In this way, by using the rigid limit between the bushing and the ball bearing, the pre-compression amount of the rubber bodies in the second rubber assembly and the first rubber assembly can be precisely controlled by designing the values of the gaps H1 and H2. After the bolt and nut reach the designed tightening torque, the bushing generates metal rigid limit to ensure the designed compression state of the rubber, and ensure that the rubber parts do not loosen under the engine load condition of the rear shock absorber. In addition, it should be noted that after pre-compression, the first bushing and the second bushing can also be used to axially limit the ball bearing.

[0027] For example, Figure 12As shown, flanges 27 are provided on the outer peripheral surfaces of one ends of the first bushing 25 and the second bushing 26. Countersunk holes 141 are provided on the top plates 14 of the first rubber component 5 and the second rubber component 6. When one ends of the first bushing 25 and the second bushing 26 contact the top plate 14, the one ends of the first bushing 25 and the second bushing 26 are respectively inserted into the countersunk holes 141 on the top plates 14 of the first rubber component 5 and the second rubber component 6, and the flanges 27 on the one ends of the first bushing 25 and the second bushing 26 are respectively in contact with the top plates 14 of the first rubber component 5 and the second rubber component 6. At this time, gaps H3 are left between the one ends of the first bushing 25 and the second bushing 26 and the bottom surfaces of the countersunk holes 141 on the top plates 14 of the first rubber component 5 and the second rubber component 6.

[0028] In summary, in the present invention, the connection position of the main bolt is set at the position between the two rubber stacks of the second rubber component and the first rubber component. In this way, as long as one main bolt is used to press the second rubber component and the first rubber component against the bottom surface and the top surface of the main bracket component, the rubber bodies in the second rubber component and the first rubber component can be pre-compressed. Thus, compared with the prior art, the connection structure of one connecting bolt is reduced, the pre-compression structure of the rubber component is simplified, the installation steps are simplified, and the weight of the entire rear shock absorber is reduced, meeting the requirements of lightweight design. In addition, with such a setting, the area of the third metal skeleton in the prior art is also reduced, further reducing the weight of the entire rear shock absorber. By designing the cooperation of the positioning protrusion and the through hole, the positions of the second rubber component and the first rubber component when pressed against the bottom surface and the top surface of the main bracket component are positioned, which can further improve the assembly accuracy and assembly speed of the rear shock absorber; in addition, the weight of the main bracket frame can also be reduced by the provided through hole 1 and through hole 2, thus further meeting the requirements of lightweight design. By designing the values of the gap H1 and the gap H2, the pre-compression amount of the rubber bodies in the second rubber component and the first rubber component can be accurately controlled. After the bolt and nut reach the designed tightening torque, the bushing generates metal rigid limit to ensure the designed compression state of the rubber, ensuring that the rubber parts do not loosen under the engine load condition of the rear shock absorber.

[0029] The "multiple" mentioned in the embodiments refers to the quantity of "two or more". The above embodiments are only for illustrating the present invention and not for limiting the present invention. Those skilled in the relevant technical fields can also make various changes or transformations without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also belong to the protection scope of the present invention, and the protection scope of the present invention should be defined by each claim.

Claims

1. A method for pre-compressing a rubber component in a rear shock absorber of a turboprop engine, wherein the rear shock absorber further comprises a main bracket component, the rubber component comprises a rubber component 1 and a rubber component 2, the main bracket component is arranged between the rubber component 1 and the rubber component 2, and is characterized in that: During installation, the main bolt is passed through the middle position of rubber component 2, the middle position of the main bracket component and the rubber component 1 in sequence and then locked with the nut, so that the rubber component 2 and the rubber component 1 are pressed against the bottom and top surfaces of the main bracket component, so that the rubber bodies in the rubber component 2 and the rubber component 1 are in a pre-compressed state.

2. The pre-compression method according to claim 1, characterized in that: The rubber component 2 and the rubber component 1 both include a top plate, a bottom plate 1 and a bottom plate 2, the rubber bodies in the rubber component 2 and the rubber component 1 both include a rubber pile 1 and a rubber pile 2, the bottom plate 1 is vulcanized and bonded to the top plate through the rubber pile 1, the bottom plate 2 is vulcanized and bonded to the top plate through the rubber pile 2, the rubber pile 1 and the rubber pile 2 are respectively located at the two 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 main bracket component 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 are in contact with the bottom surface of the main bracket component, and the bottom plate 1 and bottom plate 2 of rubber component 1 are in contact with the top surface of the main bracket component.

3. The pre-compression method according to claim 2, characterized in that: The main bolt passing through the main bracket assembly is connected with one end of the mounting frame assembly through the ball bearing 1, and the outer part of the main bolt is also sleeved with a shaft sleeve 1 and a shaft sleeve 2; the shaft sleeve 1 is located between the top plate of the rubber assembly 1 and the ball bearing 1, and the shaft sleeve 2 is located between the top plate of the rubber assembly 2 and the ball bearing 1; Before pre-compression, one end of the sleeve 1 contacts the top plate of the rubber component 1, and a gap H1 is left between the other end of the sleeve 1 and the end face of one end of the inner ring of the ball bearing 1; one end of the sleeve 2 contacts the top plate of the rubber component 2, and a gap H2 is left between the other end of the sleeve 2 and the end face of the other end of the inner ring of the ball bearing 1; after the main bolt is tightened for pre-compression, the gaps H1 and H2 are both zero; By designing the values ​​of the gap H1 and the gap H2, the pre-compression amount of the rubber body in the rubber component 2 and the rubber component 1 can be controlled.

4. The pre-compression method according to claim 3, characterized in that: A flange is provided on the outer peripheral surface of one end of the shaft sleeve 1 and the shaft sleeve 2, and a countersunk hole is provided on the top plate of the rubber component 1 and the rubber component 2; When one end of the sleeve 1 and the sleeve 2 contacts with the top plate, one end of the sleeve 1 and the sleeve 2 is respectively inserted into the countersunk holes on the top plates of the rubber components 1 and 2, and the flanges on one end of the sleeve 1 and the sleeve 2 are respectively contacted with the top plates of the rubber components 1 and 2. At this time, a gap H3 is left between one end of the sleeve 1 and the sleeve 2 and the bottom surface of the countersunk holes on the top plates of the rubber components 1 and 2.

5. The pre-compression method according to claim 2, 3 or 4, characterized in that: The main support assembly comprises a main support frame, a through hole 1 and a through hole 2 are formed on the main support frame, and a positioning protrusion 1 and a positioning protrusion 2 are respectively provided on the bottom plate 1 and the bottom plate 2 of the rubber assembly 2 and the rubber assembly 1, and the shapes of the positioning protrusion 1 and the positioning protrusion 2 match the through hole 1 and the through hole 2; During installation, the positioning protrusion 1 and the positioning protrusion 2 of the rubber component 1 are respectively inserted into one end of the through hole 1 and one end of the through hole 2 on the main bracket frame, and the positioning protrusion 1 and the positioning protrusion 2 of the rubber component 2 are respectively inserted into the other end of the through hole 1 and the other end of the through hole 2 on the main bracket frame, so that the bottom plate 1 and the bottom plate 2 of the rubber component 2 are in contact with the bottom surface of the main bracket assembly, and the bottom plate 1 and the bottom plate 2 of the rubber component 1 are in contact with the top surface of the main bracket assembly.

6. The pre-compression method according to claim 5, characterized in that: The rear shock absorber also includes a mounting frame assembly, which is arranged on one side of the main bracket assembly. One end of the mounting frame assembly is inserted into the main bracket assembly, and a main bolt passing through the main bracket assembly is connected to one end of the mounting frame assembly through a ball bearing.

7. The pre-compression method according to claim 6, characterized in that: The mounting frame assembly includes a mounting frame body, a ball bearing first mounting hole is arranged at one end of the mounting frame body, and a through hole third is also opened on the main support frame body and located between the through hole first and the through hole second; When one end of the mounting frame assembly is inserted into one side of the main bracket assembly, the central axis of the ball bearing 1 mounting hole coincides with the central axis of the through hole 3; after installation, the ball bearing 1 is arranged at a position between the outside of the rod body of the main bolt and the ball bearing 1 mounting hole, so that the main bolt passing through the main bracket assembly is connected with one end of the mounting frame assembly through the ball bearing 1.

8. The pre-compression method according to claim 7, characterized in that: The other end of the mounting frame assembly is connected to the turboprop engine, and the other side of the main bracket assembly is connected to the aircraft frame through a screw rod 1 with a ball bearing and a screw rod 2 with a ball bearing.

Images