An integrated device for detecting hydraulic damper motion displacement

Abstract

The present application relates to the technical fields of hydraulic damper motion displacement dynamic performance detection, and discloses an integrated device for detecting the motion displacement of a hydraulic damper, which comprises an outer cylinder, a damper end cover arranged at one end of the outer cylinder, a piston rod arranged in the outer cylinder in a sliding mode, a tail connecting rod connected with the piston rod and arranged at the other end of the outer cylinder, a plurality of throttle holes arranged on the piston rod, a displacement sensor arranged in the piston rod, one end of the displacement sensor connected with the damper end cover, and a sensor detection rod connected with the other end of the displacement sensor.The displacement sensor is integrated with the hydraulic damper, the damper body structure strength is not changed, the device is compact and integrated, and is installed without damage, and meanwhile, the external envelope size of the damper and the interface are not changed, the device meets the installation space, weight and assembly constraints of the helicopter rotor system area, and no external installation space is additionally reserved for the sensor.

Description

Technical Field

[0001] This invention relates to the field of dynamic performance testing technology for hydraulic dampers, and particularly to an integrated device for detecting the motion position of a hydraulic damper during reciprocating motion. Background Technology

[0002] When a helicopter rotor system is in operation, the blades generate reciprocating oscillation motion around the vertical hinge. When the blade motion frequency is coupled with the natural frequency of the rotor system, it may cause serious resonance that threatens flight safety. The hydraulic damper is a key component that provides damping to eliminate this risk when the rotor system is in operation.

[0003] During the long-term service of hydraulic dampers, the motion displacement characteristics of the damper are key parameters for evaluating its damping capability and health status. Existing testing methods are limited by the spatial structure of helicopter rotor components. External displacement sensors are difficult to install, and the cables are prone to wear and occupy external space, making them unsuitable for helicopter installation. Laser or visual inspection methods are easily affected by hydraulic fluid contamination and vibration, resulting in low reliability. Existing testing methods mostly involve ground-based bench testing, which cannot achieve real-time displacement and velocity detection of the damper under flight conditions, thus making it impossible to grasp the performance degradation of the damper under actual flight load spectrum.

[0004] Therefore, the inventors have discovered at least the following problems in the prior art: Currently, aircraft hydraulic dampers have virtually no real-time detection and recording capabilities. The basic detection method is ground bench testing, which cannot achieve real-time displacement and velocity monitoring of the damper during flight, nor can it monitor the health status of the damper. At the same time, external sensors are difficult to install in the space of the helicopter rotor system, and the cables are prone to wear. Summary of the Invention

[0005] The purpose of this invention is to provide an integrated device for detecting the motion displacement of a hydraulic damper, which can realize real-time displacement detection and recording of the hydraulic damper during flight, and monitor the health status of the damper. This solves the problems of existing helicopter hydraulic dampers being unable to achieve real-time detection capabilities and the difficulty in installing external sensors, fundamentally improving the reliability and safety of the system's hydraulic control system.

[0006] To solve the above-mentioned technical problems, the present invention provides an integrated device for detecting the motion displacement of a hydraulic damper, comprising: An outer cylinder has a damper end cap at one end, a piston rod slidably disposed inside the outer cylinder, and a tail rod connected to the piston rod at the other end of the outer cylinder; the piston rod has multiple throttling orifices. A displacement sensor is installed inside the piston rod. One end of the displacement sensor is connected to the damper end cap, and the other end of the displacement sensor is connected to a sensor detection rod. A sensor connector mounting structure is provided on the damper end cover and is used to lead out the electrical signal of the displacement sensor. The piston rod has a hollow inner hole extending along its axial direction, and the displacement sensor is fitted with multiple guide rings; the guide rings are located between the displacement sensor and the hollow inner hole, and the multiple guide rings are respectively arranged at both ends of the displacement sensor to form a two-point support structure; the displacement sensor is a magnetically encoded displacement sensor, and a magnetic encoding strip is provided on the displacement sensor, and the sensor detection rod slides axially along the surface of the magnetic encoding strip.

[0007] The damper end cap is provided with mounting holes.

[0008] The displacement sensor is located in the hollow inner hole, and one end of the displacement sensor is connected to the mounting hole.

[0009] The displacement sensor and the hollow inner hole are fitted with a clearance, and the displacement sensor and the mounting hole are connected by a thread.

[0010] The sensor detection rod is connected to the piston rod via a connecting plate.

[0011] The sensor detection rod and the connecting plate are connected by a thread.

[0012] The tail rod is pressed onto the connecting plate by a sleeve and a locking nut. An adjusting shim is provided between the sleeve and the connecting plate to adjust the installation length of the hydraulic damper.

[0013] The sensor connector mounting structure includes a socket and a plug. The socket is located on the damper end cover, and the plug is detachably connected to the socket. The plug is equipped with a tail accessory for connecting external cables.

[0014] There are two guide rings, namely guide ring one and guide ring two.

[0015] The guide ring is made of a low-friction coefficient composite material, which is PTFE composite material.

[0016] Compared to existing technologies, this invention integrates the displacement sensor with the hydraulic damper, without altering the damper's structural strength. It achieves compact integration and non-destructive installation, without increasing the damper's external envelope dimensions or requiring interface modifications. This meets the installation space, weight, and assembly constraints of the helicopter rotor system area, eliminating the need for additional external installation space for the sensor. Compared to traditional ground-based bench testing for displacement inspection, this invention enables automated and digital precise displacement-velocity measurement, facilitating full-life displacement and velocity inspection of the damper during flight. This has substantial engineering application value in improving the flight safety and packaging efficiency of helicopter rotor systems.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0018] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 yes Figure 1 A schematic diagram of the electrical interface of a medium displacement sensor.

[0020] In the diagram: 1-Damper end cap, 2-Piston rod, 2a-Throttle orifice, 3-Displacement sensor, 3a-Sensor detection rod, 4-Guide ring, 4a-Guide ring one, 4b-Guide ring two, 5-Outer cylinder, 6-Connecting plate, 7-Sleeve, 8-Adjusting shim, 9-Locking nut, 10-Tail connector rod, A1-Sensor connector mounting structure, A2-Socket, A3-Plug, A4-Tail accessory. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of this invention to facilitate a better understanding of this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this invention. The embodiments can be combined with and referenced by each other without contradiction.

[0022] Example 1 like Figure 1 The device shown is an integrated device for detecting the motion displacement of a hydraulic damper. The displacement sensor 3 is integrated inside the hydraulic damper. The piston rod 2 has reserved space for the installation of the displacement sensor 3, and a sensor connector mounting structure A1 is provided on the damper end cover 1 to ensure electrical signal access and feedback.

[0023] Specifically, when the piston rod 2 moves, the sensor detection rod 3a moves synchronously with the piston rod 2 in real time to achieve the ability to detect displacement. A guide ring 4 is set on the reciprocating friction surface between the displacement sensor 3 and the piston rod 2 to prevent the displacement sensor 3 from dry grinding with the piston rod 2 and damaging the base material. The displacement sensor 3 is connected and fixed to the hydraulic damper end cap 1 by threads to realize the integrated installation structure of the displacement sensor 3.

[0024] Furthermore, the hydraulic damper is installed on the rotor system via the damper end cap 1 and the tail rod 10. It relies on the pressure difference generated when the oil flows through the two internal throttling orifices 2a to provide damping force. When the piston rod 2 moves relative to the outer cylinder 5, the viscous oil flows in the throttling orifices 2a, and a pressure drop occurs due to pipe friction and cross-sectional changes. This pressure difference acts on the piston rod to form an axial damping force, reducing the damping and vibration of the aircraft rotor system. During the movement of the hydraulic damper, the piston rod 2 performs axial reciprocating linear motion relative to the outer cylinder 5. The displacement sensor 3 is threaded onto the end cap 1 and is placed entirely inside the piston rod 2. The sensor detection rod 3a of the displacement sensor 3 extends through the internal channel of the piston rod 2 and is fixed inside the piston rod 2 by the connecting plate 6. During operation, the displacement sensor 2 remains stationary, while the sensor detection rod 3a, connected to the piston rod 2, performs reciprocating motion, thus realizing the displacement detection of the hydraulic damper.

[0025] Preferably, the present invention adopts an integrated installation form, with a hollow structure designed inside the piston rod 2. The aperture is determined according to the outer diameter of the displacement sensor 3, and space is reserved for the installation of the displacement sensor 3. This allows the displacement sensor 3 to be installed as a whole inside the hydraulic damper. The hollow structure of the piston rod 2 itself serves as a protective cover for the displacement sensor 3, eliminating the risk of external collisions and oil impacts. The displacement sensor 3 is a slender cylinder with a clearance fit between its outer diameter and the inner hole of the piston rod 2, ensuring smooth assembly and no radial wobble. The tail end of the displacement sensor 3 is threaded and connected to the internal threaded hole of the end cover 1 for fixation, ensuring that the displacement sensor 3 is in a fixed state. During operation, the end cover 1, the outer cylinder 5, and the displacement sensor 3 are stationary, while the piston rod 2 and the tail rod 10 are in reciprocating motion. The sensor detection rod 3a moves in a reciprocating linear motion in the axial direction with the piston rod 2. The magnetic coding strip on the displacement sensor body 3 remains stationary. As the piston rod 2 moves, the sensor detection rod 3a sweeps axially along the surface of the coding strip. The number of magnetic poles swept by the sensor detection rod 3a is the displacement distance of the hydraulic damper piston rod 2 relative to the outer cylinder 5. The speed of the hydraulic damper can be calculated by the number of fixed magnetic poles swept and the time taken.

[0026] Specifically, the displacement sensor 3 is fully integrated inside the hydraulic damper, without changing the external dimensions and interface of the damper, and has no impact on the helicopter rotor system.

[0027] Furthermore, under the condition that relative axial sliding occurs between the displacement sensor 3 and the inner hole of the piston rod 2, two guide rings, 4a and 4b, are set up. The two guide rings are respectively arranged on both sides of the housing of the displacement sensor 3 to form a two-point support structure, ensuring that the axial movement direction of the displacement sensor 3 coincides with the axial direction of the inner hole of the piston rod 2, reducing the phenomenon of uneven wear, and at the same time effectively suppressing the radial tilting and swinging of the displacement sensor 3 during the movement.

[0028] Specifically, the guide ring 4 is made of low-friction coefficient PTFE composite material. During operation, it keeps the metal substrate of the displacement sensor 3 housing isolated from the metal substrate of the piston rod 2 inner hole, reducing friction and wear in unlubricated conditions. Simultaneously, given the harsh vibration environment of the aircraft rotor system, the guide ring 4 material possesses a certain elastic modulus, providing directional vibration damping during operation and protecting the displacement sensor 3. Achieving high cylindricity and straightness during the machining of the long inner hole of the piston rod 2 is difficult, and the displacement sensor 3 housing is a precision-ground part. Simply ensuring a clearance fit to improve machining accuracy would be costly. By adopting the guide ring 4 structural design, its wear-resistant nature allows it to adapt to different inner hole roundnesses. In the initial short-term wear phase, the guide ring 4 surface conforms to the actual contour of the piston rod 2 inner hole, forming the optimal fit clearance.

[0029] Furthermore, the front end of the sensor detection rod 3a is connected to the connecting plate 6 via a thread, so that the sensor detection rod 3a moves synchronously with the piston rod 2 when the piston rod 2 reciprocates, thus achieving the purpose of checking the displacement of the hydraulic damper. At the same time, the tail rod 10 is pressed onto the connecting plate 6 by the sleeve 7 and the adjusting shim 8 to prevent internal movement. Since the installation length of the hydraulic damper may be incorrect due to the error of different processed parts, this solution can set multiple adjusting shims 8 to adjust the installation length of the hydraulic damper.

[0030] Furthermore, such as Figure 2 As shown, the sensor connector mounting structure A1 is installed on the outside of the damper end cover 1. The socket A2 is fixedly installed on the damper end cover 1, forming a rigid integral with the damper end cover 1 and remaining stationary. The plug A3 and the tail accessory A4 are connected to the socket A2 to connect the external cable.

[0031] As described above, this invention achieves significant advantages such as compact structure, space saving, and weight reduction. In terms of maintenance and management, it adopts plug-in connection, which simplifies installation, optimizes working hours, and reduces costs.

[0032] Those skilled in the art will understand that the above embodiments can be modified in form and detail in practical applications without departing from the spirit and scope of the invention.

Claims

1. An integrated device for detecting the motion displacement of a hydraulic damper, characterized in that: include, The outer cylinder (5) has a damper end cap (1) at one end, a piston rod (2) is slidably arranged inside the outer cylinder (5), and a tail rod (10) connected to the piston rod (2) at the other end of the outer cylinder (5); the piston rod (2) has multiple throttling holes (2a). Displacement sensor (3), the displacement sensor (3) is installed inside the piston rod (2), one end of the displacement sensor (3) is connected to the damper end cap (1), and the other end of the displacement sensor (3) is connected to the sensor detection rod (3a). Sensor connector mounting structure (A1), which is provided on the damper end cover (1) and is used to lead out the electrical signal of the displacement sensor (3); The piston rod (2) has a hollow inner hole extending along its axial direction, and the displacement sensor (3) is fitted with multiple guide rings (4); the guide rings (4) are located between the displacement sensor (3) and the hollow inner hole, and the multiple guide rings (4) are respectively arranged at both ends of the displacement sensor (3) to form a two-point support structure; the displacement sensor (3) is a magnetically encoded displacement sensor, and a magnetic encoding strip is provided on the displacement sensor (3), and the sensor detection rod (3a) slides axially along the surface of the magnetic encoding strip.

2. The integrated device for detecting the motion displacement of a hydraulic damper as described in claim 1, characterized in that: The damper end cap (1) is provided with mounting holes.

3. The integrated device for detecting the motion displacement of a hydraulic damper as described in claim 2, characterized in that: The displacement sensor (3) is located in the hollow inner hole, and one end of the displacement sensor (3) is connected to the mounting hole.

4. The integrated device for detecting the motion displacement of a hydraulic damper as described in claim 3, characterized in that: The displacement sensor (3) is clearance-fitted with the hollow inner hole, and the displacement sensor (3) is threadedly connected to the mounting hole.

5. The integrated device for detecting the motion displacement of a hydraulic damper as described in claim 1, characterized in that: The sensor detection rod (3a) is connected to the piston rod (2) via a connecting plate (6).

6. The integrated device for detecting the motion displacement of a hydraulic damper as described in claim 5, characterized in that: The sensor detection rod (3a) and the connecting plate (6) are connected by a thread.

7. The integrated device for detecting the motion displacement of a hydraulic damper as described in claim 1, characterized in that: The tail rod (10) is pressed onto the connecting plate (6) by the sleeve (7) and the locking nut (9). An adjusting shim (8) is provided between the sleeve (7) and the connecting plate (6) to adjust the installation length of the hydraulic damper.

8. The integrated device for detecting the motion displacement of a hydraulic damper as described in claim 1, characterized in that: The sensor connector mounting structure (A1) includes a socket (A2) and a plug (A3). The socket (A2) is located on the damper end cap (1), and the plug (A3) is pluggably connected to the socket (A2). The plug (A3) is provided with a tail accessory (A4), which is used to connect external cables.

9. The integrated device for detecting the motion displacement of a hydraulic damper as described in claim 1, characterized in that: The guide ring (4) is provided in two parts, namely guide ring one (4a) and guide ring two (4b).

10. The integrated device for detecting the motion displacement of a hydraulic damper as described in claim 1, characterized in that: The guide ring (4) is made of a low-friction coefficient composite material, which is a PTFE composite material.

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