Helicopter drive shaft radial vibration displacement measuring device

Abstract

The application belongs to the technical field of helicopter comprehensive test, and particularly relates to a kind of helicopter transmission shaft radial vibration displacement measuring device, including base, two symmetrical distribution left support and right support are arranged on the upper end of base, and the laser displacement sensor of inclination is arranged on the upper end of left support and right support, and the laser displacement sensor on left support and right support points to the axis of helicopter transmission shaft, the universality of the present application is strong, can be installed in helicopter tail transmission shaft and tail inclined shaft and the like position, the on-board installation interface is simple, and installation adjustment is convenient, the structure is stable and small in deformation, and the measurement precision is high, can install sensor under limited space and monitor the radial vibration displacement of two directions of helicopter transmission shaft.

Description

Technical Field

[0001] This invention belongs to the field of helicopter integrated testing technology, and specifically relates to a radial vibration displacement measuring device for a helicopter drive shaft. Background Technology

[0002] The helicopter transmission system is one of the three major moving components of a helicopter, mainly comprising the engine power output shaft, main gearbox, tail driveshaft, intermediate gearbox, tail swashplate shaft, and tail gearbox. Its primary function is to transmit power generated by the engine to the main rotor system, tail rotor, and other accessories. During helicopter ground joint tests and scientific research flight tests, to ensure helicopter safety, it is necessary to monitor the vibration of the helicopter transmission system in real time, including the radial vibration displacement of the helicopter driveshaft in both directions. If the radial vibration displacement of the driveshaft exceeds the limit, the over-limit situation must be recorded in real time and an alarm signal issued. The helicopter driveshaft is generally fixed to the mounting platform by driveshaft bearing supports at both ends and connected to other components of the transmission system via diaphragm couplings. During rotation, the radial vibration of the driveshaft is generally greatest at the 1 / 2 mark of the driveshaft. To monitor the radial vibration displacement of the driveshaft in both directions in real time, laser displacement sensors need to be placed at the middle or other locations on the driveshaft, and a radial vibration displacement measuring device needs to be designed.

[0003] The conventional approach involves placing two laser displacement sensors horizontally and vertically on the helicopter's driveshaft, respectively, and designing two brackets to mount the sensors. However, due to the required mounting distance between the laser displacement sensors and the outer surface of the driveshaft, it's impossible to mount the sensors directly below or horizontally on the driveshaft if the driveshaft is close to the mounting platform or the engine compartment firewall. If the laser displacement sensors are mounted directly above the driveshaft, the distance between the sensor and the mounting platform is large, resulting in a large bracket. This not only poses a risk of interference with the driveshaft fairing but also risks significant vibration and deformation of the sensor bracket during test flights, potentially compromising measurement accuracy. Therefore, how to install laser displacement sensors to monitor the radial vibration displacement of the driveshaft within limited space while meeting measurement accuracy requirements has become a problem that needs to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide a radial vibration displacement measuring device for a helicopter drive shaft, which enables the installation of laser displacement sensors in two directions and the measurement of radial vibration displacement of the helicopter drive shaft within a limited installation space and while meeting measurement accuracy requirements.

[0005] The technical solution of the present invention:

[0006] A radial vibration displacement measuring device for a helicopter drive shaft includes a base 1. Two symmetrically distributed left supports 3 and right supports 9 are provided on the upper end of the base. Inclined laser displacement sensors 4 are provided on the upper ends of the left supports 3 and right supports 9, and the laser displacement sensors 4 on the left supports 3 and right supports 9 point towards the axis of the helicopter drive shaft.

[0007] Furthermore, the base 1 is provided with four sets of base mounting bolt assemblies 2, and the base 1 is mounted to the sensor mounting platform of the helicopter through the four sets of base mounting bolt assemblies 2.

[0008] Furthermore, the upper ends of the left bracket 3 and the right bracket 9 are set as inclined planes, and the installation adjustment pad 5 is installed on the inclined plane at the upper end of the left bracket 3 or the inclined plane at the upper end of the right bracket 9.

[0009] Furthermore, it also includes a peelable pad 7, which is respectively installed on the upper and lower surfaces of the laser displacement sensor 4.

[0010] Furthermore, the peelable pad 7 and the laser displacement sensor 4 are mounted to the inclined plane at the upper end of the left bracket 3 and the adjusting pad 5 at the upper end of the right bracket 9 via the sensor mounting bolt assembly 6.

[0011] Furthermore, the peelable pad 7 and the laser displacement sensor 4 are mounted on the adjusting pad 5 at the upper end of the left bracket 3 and the inclined plane at the upper end of the right bracket 9 via the sensor mounting bolt assembly 6.

[0012] Furthermore, it also includes a crossbeam 8, the two ends of which are connected to the inclined planes at the upper ends of the left bracket 3 and the right bracket 9 respectively through the sensor mounting bolt assembly 6.

[0013] Furthermore, it also includes left and right bracket mounting bolt assemblies 10, wherein the left bracket 3 and the right bracket 9 are respectively mounted to the base 1 via the left and right bracket mounting bolt assemblies 10.

[0014] Furthermore, the laser displacement sensors 4 on the upper ends of the left support 3 and the right support 9 are arranged symmetrically on the left and right sides, forming a 45° angle with the vertical direction.

[0015] Furthermore, the base 1, left bracket 3, adjusting pad 5, peelable pad 7, crossbeam 8, and right bracket 9 are all made of aluminum alloy or alloy steel.

[0016] The beneficial effects of this invention are:

[0017] This invention provides a radial vibration displacement measuring device for helicopter drive shafts. This invention is highly versatile and can be installed on helicopter tail drive shafts and tail slant shafts, etc. It has a simple onboard installation interface, is easy to install and adjust, has a stable structure with minimal deformation, and provides high measurement accuracy. It can install sensors in limited spaces and monitor the radial vibration displacement of helicopter drive shafts in two directions.

[0018] The present invention has the following advantages:

[0019] 1. The radial vibration displacement measuring device of the transmission shaft of the present invention is an integral independent frame structure. Two laser displacement sensors are symmetrically arranged on the left and right, forming a 45° angle with the vertical direction. It can measure the radial vibration displacement of the transmission shaft in two directions. The structure is stable, easy to install, has high rigidity and small deformation, can adapt to the vibration environment on the machine, and has good measurement effect and high accuracy.

[0020] 2. In order to improve the rigidity and installation stability of the base 1, the base 1 can be designed as a box or frame structure, and can be a machined part or a welded part. The design and installation of the base 1 should avoid interference with the components of the installation platform.

[0021] 3. The left support 3 and the right support 9 are connected into a whole by the crossbeam 8, which improves the rigidity and stability of the measuring device, effectively reduces the vibration and deformation of the measuring device itself in the working environment, and improves the measurement accuracy.

[0022] 4. The device of the present invention is simple and convenient to assemble and disassemble, requiring only four mounting holes to be opened on the machine, causing little damage to the machine structure, and making sensor installation and adjustment convenient;

[0023] 5. The device of the present invention is ingeniously designed. While ensuring measurement accuracy, it avoids interference with the engine compartment firewall and transmission system fairing, and will not interfere with structures such as the engine compartment firewall and the aircraft fairing. Attached Figure Description

[0024] Figure 1 Schematic diagram of laser displacement sensor installation;

[0025] Figure 2 A schematic diagram of the installation of the radial vibration displacement measuring device for the drive shaft;

[0026] Figure 3 This is a schematic diagram of a device for measuring radial vibration displacement of a drive shaft.

[0027] Figure 4 This is an exploded view of the structure of the radial vibration displacement measuring device for the drive shaft.

[0028] The components are: 1. Base; 2. Base mounting bolt assembly; 3. Left bracket; 4. Laser displacement sensor; 5. Adjustment pad; 6. Sensor mounting bolt assembly; 7. Peelable shim; 8. Crossbeam; 9. Right bracket; 10. Left and right bracket mounting bolt assembly; 11. Drive shaft; 12. Sensor mounting platform; 13. Left firewall; 14. Right firewall. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] One embodiment of the present invention is as follows: Taking a certain type of helicopter as an example, based on the requirements for monitoring the radial vibration displacement of the helicopter's driveshaft, two laser displacement sensors are positioned at the 1 / 2 mark of this driveshaft section, near the left and right firewalls of the engine compartment. Due to limited space on board, the sensors cannot be installed directly below the driveshaft 11 or in a horizontal position. This technical solution proposes to install the two sensors symmetrically on the left and right, at a 45° angle to the sensor mounting platform. The sensor installation diagram is shown below. Figure 1 A radial vibration displacement measuring device for helicopter drive shaft was designed, and its onboard installation diagram is shown below. Figure 2 As shown. The helicopter drive shaft radial vibration displacement measuring device mainly includes a base 1, a base mounting bolt assembly 2, a left bracket 3, a laser displacement sensor 4, an adjusting shim 5, a sensor mounting bolt assembly 6, a peelable shim 7, a crossbeam 8, a right bracket 9, and left and right bracket mounting bolt assemblies 10. See the detailed structural diagram below. Figure 3 .

[0031] 1. The base 1 is used to connect the left bracket 3 and the right bracket 9, and is fixed to the helicopter mounting platform by four sets of base mounting bolt assemblies 2;

[0032] 2. The left bracket 3 and the right bracket 9 are symmetrically installed on both sides of the helicopter drive shaft, and each is installed on the base 1 by 4 sets of left and right bracket mounting bolt assemblies 10, for mounting the laser displacement sensor 4;

[0033] 3. In this example, the installation diagram of the laser displacement sensor is as follows: Figure 1 As shown, the laser displacement sensor light source is not located in the center of the sensor, and its distances from the two sides of the laser displacement sensor are a and b (by convention, b > a). The distance between the two laser displacement sensor light sources and the outer surface of the drive shaft is L. When the two laser displacement sensors are installed on the left bracket 3 and the right bracket 9 respectively, if the light beam emitted by the light source of one sensor can point to the center of the drive shaft, then the light beam emitted by the light source of the other sensor cannot point to the center of the drive shaft. Therefore, an adjustment shim 5 is needed to adjust the installation height of the other sensor to ensure that the light beam emitted by the light source of that sensor can point to the center of the drive shaft. The thickness of the adjustment shim 5 is b - a. In particular, when the laser displacement sensor light source is exactly in the center of the sensor, it is not necessary to adjust the shim 5 to ensure that the light beams emitted by both laser displacement sensors point to the center of the drive shaft.

[0034] 4. Peelable pads 7 are installed on both sides of the laser displacement sensor 4 for fine-tuning the installation of the laser displacement sensor 4;

[0035] 5. The crossbeam 8 is installed directly above the drive shaft. It is connected and fixed to the left bracket 3, laser displacement sensor 4, adjusting shim 5, and peelable shim 7 via two sets of sensor mounting bolt assemblies 6. It is also connected and fixed to the right bracket 9, laser displacement sensor 4, and peelable shim 7 via two sets of sensor mounting bolt assemblies 6. The U-shaped hole design on the crossbeam 8 ensures reliable connection and fixation after sensor installation and adjustment.

[0036] Key points of this invention:

[0037] 1. The radial vibration displacement measuring device of the drive shaft is an integral independent frame structure. Two laser displacement sensors are symmetrically arranged on the left and right, forming a 45° angle with the sensor mounting platform. It can measure the radial vibration displacement of the drive shaft in two directions. The structure is stable, easy to install, has high rigidity and small deformation, can adapt to the vibration environment on the machine, and has good measurement effect and high accuracy.

[0038] 2. In order to improve the rigidity and installation stability of the base 1, the base 1 can be designed as a box or frame structure, and can be a machined part or a welded part. The design and installation of the base 1 should avoid interference with the components of the installation platform.

[0039] 3. The left support 3 and the right support 9 are connected into a whole by the crossbeam 8, which improves the rigidity and stability of the measuring device, effectively reduces the vibration and deformation of the measuring device itself in the working environment, and improves the measurement accuracy.

[0040] 4. The device is simple and convenient to assemble and disassemble, requiring only four mounting holes to be drilled on the machine, causing minimal damage to the machine structure, and making sensor installation and adjustment convenient;

[0041] 5. The device is ingeniously designed. While ensuring measurement accuracy, it avoids the engine compartment firewall 14 and the transmission system fairing, and will not interfere with the engine compartment firewall and the aircraft fairing.

[0042] During installation, first, mount the base 1 onto the drive shaft mounting platform with the pre-embedded inserts using bolts. Then, mount the left bracket 3 and right bracket 9 onto the base 1 using left and right bracket mounting bolt assemblies 10. Next, mount the adjusting shim 5 and the peelable shim 7 onto the left bracket using sensor mounting bolt assemblies 6, and mount the peelable shim 7 onto the right bracket using sensor mounting bolt assemblies 6. After installation, install the laser displacement sensor 4 and the peelable shim 7 onto the installed peelable shim in sequence. Finally, install the crossbeam 8 and secure it with nuts. After the sensor is powered on, the installation position of the laser displacement sensor can be adjusted to meet the usage requirements by adjusting the thickness of the peelable shim 7.

Claims

1. A radial vibration displacement measuring device for a helicopter drive shaft, characterized in that: The system includes a base (1), on which two symmetrically distributed left supports (3) and right supports (9) are provided at the upper end. Inclined laser displacement sensors (4) are provided at the upper ends of the left supports (3) and right supports (9), and the laser displacement sensors (4) on the left supports (3) and right supports (9) point towards the center of the helicopter drive shaft. The upper ends of the left supports (3) and right supports (9) are set as inclined planes, and mounting adjustment pads (5) are installed on the inclined plane at the upper end of the left support (3) or the inclined plane at the upper end of the right support (9). The system also includes peelable pads (7), which are respectively... Installed on the upper and lower surfaces of the laser displacement sensor (4); the peelable shim (7) and the laser displacement sensor (4) are installed on the inclined plane at the upper end of the left bracket (3) and the adjusting shim (5) at the upper end of the right bracket (9) through the sensor mounting bolt assembly (6); the peelable shim (7) and the laser displacement sensor (4) are installed on the adjusting shim (5) at the upper end of the left bracket (3) and the inclined plane at the upper end of the right bracket (9) through the sensor mounting bolt assembly (6); the laser displacement sensors (4) at the upper ends of the left bracket (3) and the right bracket (9) are arranged symmetrically on the left and right, forming a 45° angle with the vertical direction.

2. The radial vibration displacement measuring device for a helicopter drive shaft according to claim 1, characterized in that: The base (1) is provided with four sets of base mounting bolt assemblies (2), and the base (1) is mounted to the sensor mounting platform of the helicopter through the four sets of base mounting bolt assemblies (2).

3. The radial vibration displacement measuring device for a helicopter drive shaft according to claim 2, characterized in that: It also includes a crossbeam (8), the two ends of which are connected to the inclined planes at the upper ends of the left bracket (3) and the right bracket (9) respectively by sensor mounting bolt assembly (6).

4. The radial vibration displacement measuring device for a helicopter drive shaft according to claim 3, characterized in that: It also includes left and right bracket mounting bolt assemblies (10), wherein the left bracket (3) and right bracket (9) are respectively mounted on the base (1) via the left and right bracket mounting bolt assemblies (10).

5. The radial vibration displacement measuring device for a helicopter drive shaft according to claim 4, characterized in that: The base (1), left bracket (3), adjusting pad (5), peelable pad (7), crossbeam (8), and right bracket (9) are all made of aluminum alloy or alloy steel.

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