Novel oil liquid type shimmy damper

Abstract

The invention provides a novel oil liquid type shimmy damper which comprises a barrel, end covers are arranged at the two ends of the barrel, a piston is arranged in the barrel, and a first one-way valve body and a second one-way valve body are arranged at the two ends, along the center line of the piston, of the piston respectively. The two ends of the lower portion of the piston are each provided with a flow limiting plug, and the two ends of each flow limiting plug are provided with a first working oil chamber and a second working oil chamber respectively. According to the oil type shimmy damper, the problems that when a conventional shimmy damper works, the pressure dead hole phenomenon occurs, and the pressure adapts to temperature changes are solved, dynamic damping force can be stably output, and the oil type shimmy damper is precisely adjustable and can cooperate with a turning steering engine to work. And the reliability and the safety of the aircraft takeoff and landing transmission device are improved.

Description

Technical Field

[0001] This invention belongs to the field of aircraft takeoff and landing transmission devices, and specifically relates to a novel hydraulic damper. Background Technology

[0002] Throughout an aircraft's lifecycle, takeoff, landing, and taxiing are the periods with the highest risk of flight safety incidents, and the reliable operation of the landing gear transmission system plays a decisive role in ensuring flight safety. Among these incidents, the shimmy problem in the landing gear transmission system has always been a critical challenge that urgently needs to be addressed in the aviation industry. When an aircraft reaches a certain runway speed, the nose wheel of the landing gear can experience self-excited oscillations due to various complex factors, leading to shimmy. This shimmy not only accelerates the wear and tear on landing gear components, shortening their service life, but in severe cases, it can also cause loss of aircraft control, resulting in a major accident with the destruction of the aircraft and loss of life.

[0003] To address this issue, hydraulic sway dampers have been widely used in aircraft landing gear systems. However, existing hydraulic sway dampers generally suffer from several drawbacks. First, in terms of structural design, most products utilize heavy materials and complex constructions, which not only increases the aircraft's weight, leading to increased fuel consumption and operating costs, but also reduces the overall performance of the aircraft. Second, existing sway dampers have significant shortcomings in damping adjustment. They cannot flexibly and precisely adjust the damping force according to the aircraft's actual flight conditions, such as different takeoff and landing site conditions, aircraft load, and weather conditions, making it difficult to effectively suppress sway under various complex operating conditions.

[0004] Furthermore, during taxiing and turning, the landing gear's steering servo and yaw damper need to work together. However, current yaw dampers and steering servos are designed independently, lacking an effective linkage mechanism. This means that during turns, the yaw damper cannot respond to turning maneuvers in a timely manner and adjust damping forces, leading to yaw phenomena that severely affect the aircraft's handling stability and safety. Summary of the Invention

[0005] The purpose of this invention is to provide a novel hydraulic damper that solves the problems of pressure dead spots and pressure adaptability to temperature changes that occur in conventional dampers. This allows for stable and precisely adjustable dynamic damping force output. The hydraulic damper features a simple and reliable structure, lightweight characteristics, customizable damping, high control precision, and can work in conjunction with turning servos. This improves the reliability and safety of aircraft takeoff and landing transmission devices and meets the stringent requirements of the aviation industry.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a novel oil-type damper, comprising a cylinder, end caps at both ends of the cylinder, a piston inside the cylinder, and a first one-way valve body and a second one-way valve body respectively disposed at both ends of the piston along its center line; a flow-limiting plug is provided at each end below the piston, and a first working oil chamber and a second working oil chamber are respectively disposed at both ends of the flow-limiting plug; a compensation chamber communicating with the cylinder is also provided on the outer wall of the cylinder, the compensation chamber comprising a pressure cap, steel balls, a spring piston, an upper plug and a lower plug, the upper end of the pressure cap being provided with an upper plug and the lower end being sealed by a spring retainer ring, the upper end of the spring retainer ring being connected to the lower plug, and a spring piston and steel balls being disposed between the upper plug and the lower plug.

[0007] A further improvement is that one end of the first one-way valve body and the second one-way valve body is fixed with a one-way valve seat by a snap ring, and the other end is provided with a baffle.

[0008] A further improvement is that a lever is also provided on the outer wall of the cylinder.

[0009] A further improvement is that exhaust plugs are provided at the left and right ends of the top of the cylinder.

[0010] A further improvement is that a throttling orifice is provided in the middle of the flow restrictor, and the throttling orifice connects the first working oil chamber and the second working oil chamber.

[0011] A further improvement is that the piston is made of aluminum bronze.

[0012] A further improvement is that the lever is connected to the external landing gear cylinder.

[0013] A further improvement is that a pair of fixed lugs are provided on the outer cylinder of the cylinder.

[0014] Beneficial technical effects of the present invention: 1. By using a piston, flow restrictor, and throttling orifice structure, the flow of oil between the two working oil chambers is precisely controlled. When shimmy occurs in the landing gear, this precise throttling mechanism can quickly generate a stable and suitable damping force, effectively suppressing the shimmy phenomenon. Compared with traditional shimmy dampers, this invention has a more significant effect on suppressing shimmy, greatly improving the stability of the aircraft during takeoff, landing, and taxiing, and ensuring flight safety.

[0015] 2. Through the design of the compensation chamber, the pressure cap, steel balls, spring piston and other components work together to accurately replenish the working oil chambers under the control of the one-way valve when the gyroscope is working. This not only solves the pressure dead spot problem when conventional gyroscopes are working, but also enables the pressure to adapt to temperature changes and ensures stable output of dynamic damping force. No matter what complex flight conditions, the gyroscope can operate stably and the reliability is greatly improved.

[0016] 3. The piston is manufactured using materials such as aluminum bronze, which effectively reduces the weight of the damper while ensuring mechanical strength, achieving significant weight reduction and eliminating unnecessary parts and complex structures. This not only reduces the overall weight of the aircraft and improves fuel efficiency, but also reduces the probability of failure and maintenance costs due to the simplified structure.

[0017] 4. The transmission device design, which connects the lever to the landing gear cylinder via a linkage mechanism, enables the damper to work efficiently with the turning servo. During the aircraft's turn, the damper can adjust the damping force in a timely manner according to the turning action, simultaneously achieving the functions of turning and damping. This effectively avoids the control difficulties caused by yaw during turns, significantly enhances the aircraft's control stability during taxiing and turning, and improves flight safety and comfort. Attached Figure Description

[0018] Figure 1 This is a front view of the oil-type sway damper device of the present invention; Figure 2 This is a top view of the oil-type sway damper device of the present invention; Figure 3 This is a side view of the oil-type sway damper device of the present invention; Figure 4 yes Figure 1 Sectional view of AA; Reference numerals in the attached drawings: 1-End cap, 2-Cylinder body, 3-Flow limiting plug, 4-First one-way valve body, 5-Lever, 6-Piston, 7-Baffle, 8-One-way valve body, 9-Second one-way valve seat, 10-Spring snap ring, 11-Exhaust plug, 12-Upper cover, 13-Snap ring, 14-Lower plug cap, 15-Pressure cap, 16-Steel ball, 17-Spring piston, 18-Upper plug cap, First working oil chamber-19, Second working oil chamber-20, Compensation chamber-21, Fixed lug-22. Detailed Implementation

[0019] The present application will be further described in detail below with reference to the accompanying drawings.

[0020] like Figure 1-4As shown, a novel hydraulic damper includes a cylinder 2 with end caps 1 at both ends. A piston 6 is disposed inside the cylinder 2. A first one-way valve body 4 and a second one-way valve body 8 are respectively disposed at both ends of the piston 6 along its center line. A flow-limiting plug 3 is disposed at each end below the piston 6, with a first working oil chamber 19 and a second working oil chamber 20 respectively disposed at both ends of the flow-limiting plug 3. A compensation chamber 21 communicating with the cylinder 2 is also disposed on the outer wall of the cylinder 2. The compensation chamber 21 includes a pressure cap 15, a steel ball 16, a spring piston 17, an upper plug cap 18, and a lower plug cap 14. The upper end of the pressure cap 15 is provided with the upper plug cap 18, and the lower end is sealed by a spring retainer 13. The upper end of the spring retainer 13 is connected to the lower plug cap 14. The spring piston 17 and the steel ball 16 are disposed between the upper plug cap 18 and the lower plug cap 14.

[0021] One end of the first one-way valve body 4 and the second one-way valve body 8 is fixed with a one-way valve seat 9 by a snap ring 10, and the other end is provided with a baffle 7. A lever 5 and a pair of fixed lugs 22 are also provided on the outer wall of the cylinder 2. Exhaust plugs 11 are provided at the left and right ends of the top of the cylinder. A throttling hole is opened in the middle of the flow limiting plug 3. The throttling hole is connected to the first working oil chamber 19 and the second working oil chamber 20. The piston 6 is made of aluminum bronze. The lever 5 is connected to the external landing gear rotary cylinder.

[0022] Specifically: the cylinder 2 is securely mounted on the landing gear with bolts by means of the fixed lug 22, and the lever 5 is connected to the landing gear cylinder through the linkage mechanism. This connection method can efficiently transmit motion and ensure that the damper responds to the landing gear shimmy in a timely manner.

[0023] At the top left and right ends of the cylinder 2, there are exhaust plugs 11 that serve both exhaust and refueling functions. The end caps 1 at both ends of the cylinder 2 are fastened to the cylinder 2 by threaded connection.

[0024] Piston 6 is made of aluminum bronze, a material that combines good mechanical properties with corrosion resistance. At each end of the piston's centerline, a one-way valve body 8 is positioned for refueling. The one-way valve body 8 is tightly pressed against the one-way valve seat 9 by a snap ring, and a sealing ring is used between the one-way valve body 8 and the one-way valve seat 9 to ensure sealing and one-way flow during the refueling process. At each end below piston 6, a flow-limiting plug 3 is located. The flow-limiting plug 3 has a throttling orifice in its center. This orifice serves as the only channel connecting the two working oil chambers, playing a crucial throttling role during oil flow. When the damper is in operation, the pressure difference generated by the pressure change in the first working oil chamber 19 and the second working oil chamber 20 immediately activates the compensation chamber. The compensation chamber consists of a pressure cap 15, steel balls 16, a spring piston 17, and an upper plug 18, and is securely fixed to the outer cylinder of the cylinder body 2 via threaded connections. Below the spring retainer 13, there is also an upper cover 12 that communicates with the cylinder 2. Under the precise control of the one-way valve body 8, the oil in the compensation chamber can accurately replenish the working oil chamber, thereby ensuring that the damper can operate stably under different working conditions and effectively improving the reliability and adaptability of the damper.

[0025] During takeoff and landing, when the aircraft's runway speed increases and the landing gear shows signs of shimmy, the damper responds quickly. The piston 6, flow restrictor 3, and throttle orifice structure precisely regulate the oil flow, generating appropriate damping force to effectively suppress shimmy and ensure smooth taxiing. The compensation chamber 21, based on changes in the working oil chamber pressure, precisely replenishes oil through the one-way valve body 8, ensuring a stable output of dynamic damping force to cope with different operating conditions. The aluminum bronze piston 6 and its simplified structure achieve lightweight design, reducing aircraft weight, improving fuel efficiency, and reducing maintenance costs. When the aircraft turns, the lever 5 and linkage mechanism work in conjunction with the steering servo to allow the damper to adjust the damping force in a timely manner, preventing shimmy during turns and enhancing handling stability.

Claims

1. A novel oil-based sway damper, comprising a cylindrical body (2), wherein end caps (1) are provided at both ends of the cylindrical body (2), characterized in that, A piston (6) is provided inside the cylinder (2). A first one-way valve body (4) and a second one-way valve body (8) are respectively arranged at both ends of the piston (6) along the center line of the piston (6). A flow limiting plug (3) is provided at each end below the piston (6). A first working oil chamber (19) and a second working oil chamber (20) are respectively provided at both ends of the flow limiting plug (3). A compensation chamber (21) communicating with the cylinder (2) is also provided on the outer wall of the cylinder (2). The compensation chamber (21) includes a pressure cap (15), a steel ball (16), a spring piston (17), an upper plug cap (18) and a lower plug cap (14). The upper end of the pressure cap (15) is provided with an upper plug cap (18), and the lower end is sealed by a spring retainer (13). The upper end of the spring retainer (13) is connected to the lower plug cap (14). A spring piston (17) and a steel ball (16) are provided between the upper plug cap (18) and the lower plug cap (14).

2. The novel oil-based sway damper according to claim 1, characterized in that, One end of the first one-way valve body (4) and the second one-way valve body (8) are respectively fixed with a one-way valve seat (9) by a snap ring (10), and the other end is respectively provided with a baffle (7).

3. The novel oil-based sway damper according to claim 1, characterized in that, A lever (5) is also provided on the outer wall of the cylinder (2).

4. The novel oil-based sway damper according to claim 1, characterized in that, The top of the cylinder is provided with exhaust plugs (11) at the left and right ends respectively.

5. A novel oil-based sway damper according to claim 1, characterized in that, The flow restrictor (3) has a throttling hole in the middle, which is connected to the first working oil chamber (19) and the second working oil chamber (20).

6. A novel oil-based sway damper according to claim 1, characterized in that, The piston (6) is made of aluminum bronze.

7. A novel oil-based sway damper according to claim 3, characterized in that, The lever (5) is connected to the external landing gear rotary cylinder.

8. A novel oil-based sway damper according to claim 1, characterized in that, The outer cylinder of the cylinder (2) is also provided with a pair of fixed lugs (22).

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