CN-121977823-A - Gear traveling wave resonance measurement monitoring system based on derived noise measurement method

CN121977823ACN 121977823 ACN121977823 ACN 121977823ACN-121977823-A

Abstract

The invention provides a gear traveling wave resonance measurement monitoring system based on a derived noise measurement method, and relates to the technical field of aeroengine state detection and fault diagnosis. The device comprises a microphone, a preamplifier, a microphone base, an acoustic waveguide tube, a reflection-free tail end attenuation tube, a seven-core aviation plug, a seven-core special cable, a data acquisition instrument and a computer. Firstly, constructing a signal deriving channel based on an acoustic waveguide, realizing transmission and collection of acoustic signals through a microphone base, then configuring a reflection-free tail end attenuation tube to eliminate standing wave interference, integrating pressure direct current component measurement to perform signal compensation, collecting gear noise signals in real time by utilizing a microphone and a data acquisition instrument, and identifying travelling wave resonance characteristics through spectrum analysis. The invention improves the durability and the measurement reliability of the system, and can directly measure the frequency and the rotation speed of the gear when the gear generates traveling wave resonance. The reflection-free end attenuation tube design can effectively inhibit standing wave formation, and the measurement accuracy of noise signals is guaranteed.

Inventors

LUAN XIAOCHI
SHA YUNDONG
ZHAO FENGTONG
GUO XIAOPENG

Assignees

沈阳航空航天大学

Dates

Publication Date: 20260505
Application Date: 20251224

Claims (4)

1. The gear traveling wave resonance measurement monitoring system based on the derived noise measurement method is characterized by comprising a microphone (3), a preamplifier (2), a microphone seat body (4), an acoustic waveguide tube, a reflection-free tail end attenuation tube (1), a seven-core aviation plug (40), a seven-core special cable, a data acquisition instrument and a computer; The pressure sensor comprises a microphone seat body (4), a microphone (3) and a pre-amplifier (2), wherein the pressure inside a gear box to be measured is transmitted to the microphone seat body (4) through an acoustic waveguide, a pressure cavity (38) in the microphone seat body (4) is used for sensing a pressure direct current component in the acoustic waveguide through an internal pressure equalizing hole (5), the microphone diaphragm inside the microphone seat body (4) is balanced front and back, the microphone (3) and the pre-amplifier (2) are used for measuring sound pressure in the acoustic waveguide, the microphone seat body (4) is connected with all parts, one end of the microphone seat body (4) is connected with the acoustic waveguide, the other end of the microphone seat body is connected with a non-reflection end attenuation tube (1), the non-reflection end attenuation tube (1) is connected with the acoustic waveguide and the opposite side of the microphone seat body (4) to attenuate sound waves to prevent sound waves from reflecting in the tube to form standing waves to influence the dynamic range of a testing system, the microphone (3) is arranged in the microphone seat body (4) to ensure that the microphone is arranged flush with the seat body hole wall, the tail end of the non-reflection end attenuation tube (1) is used for sealing the microphone, the microphone seat body is connected with the acoustic waveguide, the microphone seat body (4) is connected with the inner diameter of the acoustic waveguide, the non-reflection end attenuation tube (1) is connected with the acoustic waveguide through a special data acquisition device, and the data acquisition device is connected with the seven-wire through a cable, and the special data acquisition device is connected with the aviation cable through the plug, and the data acquisition device is connected with the data acquisition device.
2. The gear traveling wave resonance measurement monitoring system based on the derived noise measurement method as set forth in claim 1, wherein the acoustic waveguide is constructed based on acoustic measurement and rigid wall acoustic wave, and the inner radius a of the acoustic waveguide is calculated according to formula (1) to ensure that the measured acoustic wave signals in the required frequency range can be propagated to the sensitive surface of the microphone in the form of plane waves, namely, the cut-off frequency of the required pipeline Greater than the highest frequency of the acoustic wave to be measured; (1); wherein a is the radius of the acoustic waveguide tube, m, c is the sound velocity, m/s; The design of the acoustic waveguide tube is divided into an outer region and an inner region of the gearbox to be tested, namely an outer section (6) of the acoustic waveguide tube and an inner section (7) of the acoustic waveguide tube, the total length of the inner acoustic waveguide tube and the outer acoustic waveguide tube is fixed, the outer length is equal to the inner length, the inner acoustic waveguide tube and the outer acoustic waveguide tube are respectively copper tubes (8), and a connecting section copper tube A (9), a nut (10), an adapter (11) and a transitional adapter (12) are sequentially adopted from the outer section to the inner section to connect the outer section with an inner short tube (13) together so as to complete the arrangement of the acoustic waveguide tube.
3. The gear traveling wave resonance measurement monitoring system based on the derived noise measurement method as set forth in claim 1, wherein the reflection-free end attenuation tube (1) is configured by setting the axial coordinates of points A and B on the axis of the tube cavity as And The reflection-free end attenuation tube is designed according to the formula (2) and the formula (3): (2); (3); In the formula, Is the difference of sound pressure levels of two ends on the axis of the circular tube; is the attenuation coefficient; the noise elimination coefficient is the noise elimination coefficient of the pipeline material; The circumference of the section of the pipeline is m; The unit is m 2 , which is the sectional area of the pipeline; When the attenuation constant is fixed, the length of the tube is increased to enable The method is large enough, and reverse waves in the tube cavity can be ignored, namely standing waves in the tube cavity are eliminated, and the dynamic range and the frequency response characteristic of the measuring system are ensured; the multiple adapters are connected through nuts, then the round copper pipe is connected with the adapter C through the connection section copper pipe B, and the reflection-free tail end attenuation pipe (1) is arranged.
4. The system for measuring and monitoring the traveling wave resonance of the gear based on the derived noise measurement method as set forth in claim 1, wherein in the design of the pressure cavity (38) and the equalizing hole (5) of the microphone base (4), the natural frequency of the pressure cavity (38) is determined according to the formula (4): (4); In the formula, Is the natural frequency of a pressure cavity (38) in the microphone seat body (4); is the cross section area of a pressure equalizing hole (5) in the microphone seat body (4); Is the volume of the pressure chamber (38); is the length of the pressure equalizing hole (5); determining the volume of a pressure cavity (38) according to the frequency lower limit value of the frequency response range designed by the monitoring system, and designing the size of a pressure equalizing hole (5) according to the volume of the cavity; The microphone seat body (4) is seen from bottom to top, three fixing threaded holes are reserved below the bottom of the supporting seat, a pair of transition adapter A (28) is connected to the opposite side and used for connecting an acoustic waveguide tube and a reflection-free tail end attenuation tube (1), a copper gasket (31) is arranged above the adapter, an O-shaped rubber gasket (33) is further used between a pressure cavity (38) and the supporting seat, an amplifier and a microphone (35) in the pressure cavity (38) are sequentially positioned and fixedly installed from bottom to top through a supporting screw (26), a compression nut (27), a positioning clamp ring (34), a spring (36) and a positioning cavity (37), the positioning clamp ring (34) is fixed through an inner hexagon screw M3x10 (29) and a nut M3 (30), the pressure cavity (38) and the upper side of the positioning cavity (37) are fixed through an inner hexagon screw M6 (21), an inner hexagon screw M3 (22) and an inner hexagon screw M2 (23), and the uppermost seven aviation plug (40) is fixedly installed and connected with the microphone seat body (35) through a clamping ring (24) and a clamping cover plate (25), and the microphone seat body is fixedly installed.

Description

Gear traveling wave resonance measurement monitoring system based on derived noise measurement method Technical Field The invention relates to the technical field of aeroengine state detection and fault diagnosis, in particular to a gear traveling wave resonance measurement monitoring system based on a derived noise measurement method. Background Modern aero-engines develop in the direction of large thrust-weight ratio, high load, high efficiency and high intelligence, and new requirements of high speed, heavy load and light weight are put forward for accessory transmission systems of the aero-engines. The gear is used as one of the most important parts in the transmission system, and the structure of the gear has the characteristics of light weight, thinness and small rigidity. Meanwhile, because the working environment is in high temperature, high rotating speed and alternating heavy load and is in a typical disc-shaped structure, traveling wave resonance easily occurs in the working rotating speed range, so that gear block breakage failure is caused, great potential safety hazards are brought to stable operation of an engine, and in recent years, a plurality of gear block falling faults of an accessory transmission system of an aeroengine, which are caused by the traveling wave resonance of the gear, occur. Because of the transmission characteristics of the central transmission bevel gear of the aeroengine and the transmission characteristics of the engine-attached box gear system of the aeroengine and the working environment of high-temperature oil mist, the traveling wave resonance characteristics of the central transmission bevel gear and the engine-attached box gear system of the aeroengine are difficult to monitor by a conventional vibration and stress measurement method. At present, the gear traveling wave resonant frequency and rotating speed testing method mainly comprises a strain testing method and a sound testing method. The strain test method has high test precision, but the strain gauge has high adhesion difficulty, low survival rate and complex test. The other method for measuring the travelling wave resonance frequency and the resonance rotating speed is a sounding method based on a non-contact measurement mode, and for the corresponding method, a measuring sensor of the sounding method is positioned in a static coordinate system, so that the travelling wave resonance frequency of the gear can be directly measured. As the acoustic method is a non-contact measurement method, the method has the advantages of simple test and easy installation, and is suitable for gear travelling wave resonance fatigue detection experiments. However, the existing acoustic device cannot accurately measure and monitor the traveling wave resonant frequency and the rotating speed of the gear under extremely complex working environments. Therefore, the simple (meeting the requirements of small change, easy installation and the like) and accurate gear traveling wave resonance monitoring device under the high-temperature oil mist environment is designed, and important support is provided for researching the gear traveling wave resonance fracture characteristics. Disclosure of Invention Aiming at the defects of the prior art, the technical problem to be solved by the invention is to provide the gear traveling wave resonance measurement monitoring system based on the derived noise measurement method, which has reasonable structure, strong anti-interference capability and high measurement precision and is suitable for high-temperature oil mist environments such as a gear box of an aeroengine. In order to solve the technical problems, the invention adopts the following technical scheme: A gear traveling wave resonance measurement monitoring system based on a derived noise measurement method comprises a microphone, a preamplifier, a microphone seat body, an acoustic waveguide tube, a reflection-free tail end attenuation tube, a seven-core aviation plug, a seven-core special cable, a data acquisition instrument and a computer; The method comprises the steps of firstly, utilizing an acoustic waveguide tube to transmit pressure in a gear box to be tested to a microphone seat body, enabling a pressure cavity in the microphone seat body to sense pressure direct current components in the acoustic waveguide tube through an internal pressure equalizing hole, balancing front and back of a microphone diaphragm in the microphone seat body, enabling the microphone to be used for measuring sound pressure in the acoustic waveguide tube, connecting each component through the microphone seat body, enabling one end of the microphone seat body to be connected with the acoustic waveguide tube, enabling the other end of the microphone seat body to be connected with a reflection-free tail end attenuation tube, enabling the reflection-free tail end attenuation tube to be connected with the opposite sides of the acoustic waveguide tube and the