An on-line engine oil cerametric wear ultrasonic detection sensor and method

Abstract

The present application relates to the field of oil detection, and discloses an online engine oil ceramic wear debris ultrasonic detection sensor and a detection method, which adopts an ultrasonic detection sensor to perform online detection on ceramic wear debris in a lubricating oil system, a plurality of ultrasonic generators and ultrasonic receivers are arranged in a ring array or a multi-stage cascade mode in the sensor, each group corresponds to a focusing area, and a plurality of piezoelectric ceramic chips are arranged in each group, sound waves are split into a plurality of sub-waves to form a plurality of transmitting / receiving units; the lubricating oil is used as a propagation medium, when ceramic grinding exists in the lubricating oil in the corresponding focusing area, the signal received by the ultrasonic receiver is distorted, the signal received by the ultrasonic receiver is amplified and denoised by a signal processor, the processed signal is analyzed, the number and size of the wear debris in the lubricating oil system are indirectly evaluated, and the remaining life of an aero-engine bearing is predicted. The detection method is simple and reliable, and has high detection capability for small ceramic wear debris.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil debris detection, and particularly relates to an online engine oil ceramic debris ultrasonic detection sensor and method. BACKGROUND

[0002] The number and size of the debris in the lubricating oil system of an aero-engine are a key parameter for representing the bearing wear or failure. Since most bearings are made of ferromagnetic materials, the oil debris in the aero-engine running rotation is mostly detected by an electromagnetic detection method, and the failure time of the ferromagnetic bearing can be reliably warned. With the progress of technology, the emergence of ceramic bearings makes the design of aero-engines have more choices. The wear resistance of ceramic bearings is much higher than that of conventional bearings made of ferromagnetic materials, but at the same time, it also brings another problem, that is, the existing electromagnetic monitoring technology cannot be used to monitor the ceramic debris in the lubricating oil. This is because the ceramic debris does not have the properties of electrical conductivity and magnetism, so it cannot be monitored online. As a modern aero-engine structure health and safety monitoring, the bearing debris monitoring in the lubricating oil is very important. So far, there is no relevant research report on the online nondestructive detection / monitoring technology of the ceramic debris in the lubricating oil of the aero-engine. The present application researches a detection method of the ceramic debris in the lubricating oil on the basis of the prior art to realize the structure health and safety monitoring of the aero-engine. SUMMARY

[0003] To solve the above problems, the present application provides an online engine oil ceramic debris ultrasonic detection sensor and method, which is realized in the following way.

[0004] An online engine oil ceramic debris ultrasonic detection sensor adopts an ultrasonic detection sensor to perform online detection on the ceramic debris in the lubricating oil system of an aero-engine, and the ultrasonic detection sensor is connected in series in the oil circuit of the lubricating oil system. The ultrasonic detection sensor comprises a sensor shell and a plurality of groups of ultrasonic generators and ultrasonic receivers arranged oppositely and arranged in the sensor shell, and each group of ultrasonic generators and ultrasonic receivers corresponds to a detection focusing area. The plurality of groups of ultrasonic generators and ultrasonic receivers are designed in an array, and the plurality of detection focusing areas comprehensively cover the entire area of the oil flowing through the ultrasonic detection sensor. Further, each group of ultrasonic generators and ultrasonic receivers is provided with a plurality of piezoelectric ceramic chips to form a plurality of transmitting / receiving units.

[0005] In one embodiment, the ultrasonic detection sensor further comprises an annular sensor skeleton adapted to the cross section of the oil guide pipe, and the plurality of groups of ultrasonic generators and ultrasonic receivers are arranged in an annular array on the inner wall of the annular skeleton and are in contact with the oil.

[0006] As a further improvement, in the ring array structure, the arrangement of the ultrasonic generator and the ultrasonic receiver is that the ultrasonic generator and the ultrasonic receiver are respectively arranged on one side, and the opposite ultrasonic generator and the ultrasonic receiver correspond to each other with the center of the ring as the axis.

[0007] Alternatively, the ultrasonic generator and the ultrasonic receiver are staggered, and the opposite ultrasonic generator and the ultrasonic receiver correspond to each other with the center of the ring as the axis.

[0008] Another embodiment is that the ultrasonic detection sensor comprises a sensor skeleton adapted to the cross section of the oil guide pipe, the sensor skeleton is in the form of a strip-shaped grid, and the oil can pass through the grid, and the corresponding ultrasonic generator and ultrasonic receiver are respectively arranged on two adjacent grid strips to form a multi-stage cascade arrangement.

[0009] As a further improvement, the ultrasonic generator and the ultrasonic receiver are respectively arranged in an array along the extension direction of the grid strip.

[0010] As a further improvement, the surface of the piezoelectric ceramic wafer is coated with an insulating layer, and the outside of the insulating layer is plated with a metal film to form a multi-stage capacitor stage.

[0011] The application also discloses an online engine oil ceramic abrasive ultrasonic detection method, which adopts the ultrasonic detection sensor as described above for online detection.

[0012] As a further improvement, the specific detection steps are as follows:

[0013] S1: The ultrasonic detection sensor is used to pre-set and encode the detection energy focusing area of the corresponding ultrasonic generator and ultrasonic receiver (AA', BB', CC'...I I'), and the area of the ultrasonic detection sensor in series on the oil guide pipe is defined as the detection area, and the plurality of focusing areas comprehensively cover the detection area.

[0014] S2: During detection, the controller controls the ultrasonic generator to emit an acoustic wave detection signal, the acoustic wave detection signal is split into a plurality of sub-waves, and the sub-waves are transmitted in the focusing area through the oil, and when the ceramic abrasive particles are encountered, the signal is distorted to generate scattered waves, and the corresponding ultrasonic receiver receives the echo signal.

[0015] S3: Signal amplification and processing are performed on the echo signals collected in each focus area, the processing mode is denoising, and the echo signals collected in each focus area are isolated and processed to remove stray signals and pipe wall echo signals in the focus area;

[0016] S4: The echo signals processed in the previous step are converted into analog signals, and the detected data are transmitted to an analysis display, and the number and size of ceramic abrasion in each focus area are calculated through a particle detection model.

[0017] As a further improvement, the data screening of step S3 further includes removing the signals detected by overlapping between focus areas.

[0018] As a further improvement, the ultrasonic generators are synchronized to emit signals, and the same frequency and waveform of the signal wave are adopted; the emission angle of the signal wave is adjusted according to the position of the different ultrasonic generators and the preset focus area.

[0019] The signal wave is a continuous wave or a pulse wave; when the signal wave is a pulse wave, it can be a rectangular wave, a sawtooth wave, a triangular wave, a sharp peak wave or a step wave.

[0020] Compared with the prior art, the present application can obtain the following technical effects:

[0021] Firstly, the present application creates a new device and method for online detection of engine oil ceramic abrasion, adopts ultrasonic transmission detection technology, and the ultrasonic transmission method can effectively detect ceramic abrasion in oil, the detection sensor is connected in series in the oil circuit of the oil system, and oil is directly used as a coupling agent, so that the structure is simple and the result is reliable.

[0022] Secondly, the present application sets multiple groups of corresponding ultrasonic generators and ultrasonic receivers, and the annular array is arranged to comprehensively cover the detection area, and the ultrasonic sensor adopts multiple piezoelectric ceramic chips to form multiple transmission and receiving units, which further improves the detection and monitoring sensitivity of the micro ceramic abrasion, obtains related information of the viscosity of the oil, and improves the detection capability of the device.

[0023] Thirdly, the present application sets a multi-cascade detection structure to form multiple detection channels, comprehensively covers the detection area, improves the integrity of the detection result, coats an insulating layer on the surface of the piezoelectric ceramic chip, and further coats a metal film layer on the outer surface of the insulating layer to form a multi-stage capacitor electrode, so that when the particle concentration in the oil changes, the capacitance value also changes, the abrasion concentration is indirectly measured by monitoring the change of the capacitance value, and the comprehensive evaluation capability of the present application is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the present application or the prior art or the description in the prior art, the accompanying drawings are briefly introduced, and obviously, for those skilled in the art, other drawings can be obtained without creative labor.

[0025] Figure 1 The external structure of the ultrasonic detection sensor used in the present application is briefly shown in the figure.

[0026] Figure 2 The figure is Figure 1 a schematic view in the top view direction.

[0027] Figure 3 The figure is Figure 1 a schematic view in the front view direction.

[0028] Figure 4 The figure is a schematic view of the ring array type ultrasonic detection sensor of the present application along Figure 2 the A-A line in the figure.

[0029] Figure 5 The figure is a schematic view of the ring array type ultrasonic detection sensor of the present application along Figure 2 the B-B line in the figure (ultrasonic generator and ultrasonic receiver arranged on one side).

[0030] Figure 6 The figure is a schematic view of another ring array type ultrasonic detection sensor of the present application along Figure 2 the B-B line in the figure (ultrasonic generator and ultrasonic receiver staggered arrangement).

[0031] Figure 7 The figure is a schematic view of the multi-stage cascade type ultrasonic detection sensor of the present application along Figure 2 the B-B line in the figure.

[0032] Figure 8 The figure is Figure 7 a schematic view of the sound wave detection focusing.

[0033] Figure 9 The figure is a schematic view of the multi-stage cascade type ultrasonic detection sensor of the present application along Figure 3 the C-C line in the figure.

[0034] Figure 10 The figure is a schematic view of the multi-stage cascade type ultrasonic detection sensor of the present application.

[0035] Figure 11 The figure is a schematic flow chart of the detection method of the present application.

[0036] In the figure:

[0037] 10 - oil guide pipe;

[0038] 20 - ultrasonic detection sensor, 21 - sensor housing, 22 - ultrasonic generator, 23 - ultrasonic receiver, 24 - sensor skeleton, 241 - grid bars;

[0039] 30 - ceramic wear debris. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application.

[0041] In the description of the present application, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0042] During the operation of the aero-engine equipment, contact friction between parts is prone to occur, especially the engine bearing. In extreme working conditions, particles generated by wear are common, and these particles will continuously circulate and accumulate with the engine oil system. If they are not detected and cleaned in time, it is easy to cause equipment failure. At the same time, the number and size of the abrasive particles are also important parameters reflecting the health condition of the engine equipment. Therefore, it is of great significance to monitor the engine oil online.

[0043] The traditional engine bearing is made of metal material, so the abrasive particles in the oil are mainly ferromagnetic metal particles. Based on various principles, a variety of abrasive particle monitoring sensors emerge in an endless stream, including electromagnetic type, optical type, and ray type. Among them, the electromagnetic detection method is currently a better method for monitoring oil abrasive. With the development of bearing technology and the use of new materials, ceramic bearings are applied in engines due to their superior performance. Ceramic abrasive is generated during the operation of the equipment, but ceramic abrasive does not have conductivity and magnetism, and obviously cannot be used for the original online monitoring method. The monitoring of oil abrasive also faces new research and development challenges. In the research of domestic and foreign experts, it can be seen that ultrasonic waves have good detection effect on particles in liquid, but so far there is no good design of ultrasonic particle sensor and related detection method. Based on this, further, combined with the current status of the development of bearing technology, that is, with the application of ceramic bearings, the online detection of ceramic abrasive in the aircraft engine oil system by using ultrasonic detection method is studied, and the specific detection scheme is as follows.

[0044] Reference to the accompanying drawings Figures 1-11 The application discloses an online engine oil ceramic abrasive wear ultrasonic detection sensor, which adopts an ultrasonic detection sensor 20 to detect ceramic abrasives in an aircraft engine lubricating oil system in an online mode, the ultrasonic detection sensor 20 is connected in series on an oil circuit of the lubricating oil system, and the ultrasonic detection sensor 20 comprises a sensor shell 21 and a plurality of groups of ultrasonic generators 22 and ultrasonic receivers 23 arranged oppositely and arranged in the sensor shell 21, and each group of the ultrasonic generators 22 and the ultrasonic receivers 23 corresponds to a detection focusing area, the plurality of groups of the ultrasonic generators 22 and the ultrasonic receivers 23 are designed in an array mode, and the plurality of detection focusing areas comprehensively cover all areas of oil flowing through the ultrasonic detection sensor 20; further, each group of the ultrasonic generators 22 and the ultrasonic receivers 23 is provided with a plurality of piezoelectric ceramic wafer groups to form a plurality of transmitting / receiving units.

[0045] Most of the existing ultrasonic abrasive particle detection models are established for single abrasives, and the assumption of the general model is that the abrasives are in the focusing area of the ultrasonic generator transmitting sound waves, and the focusing area of the sound waves is limited. When the number of particles is large and the distribution position is uncertain, the particles appearing in the non-focusing area are easy to be missed. Especially in the detection of ceramic abrasives 30 in the engine oil, the content of the abrasives in the oil is uncertain, and the activity area of the abrasives flowing with the oil cannot be predicted. On the basis of the traditional detection method and model, the application is improved, a plurality of groups of corresponding ultrasonic generators 22 and ultrasonic receivers 23 are arranged, the focusing area of the sound waves is comprehensively covered through the ingenious arrangement, meanwhile, the ultrasonic detection sensor 20 adopts a plurality of piezoelectric ceramic wafers to form a plurality of transmitting and receiving units, the emitted sound waves are further decomposed into a plurality of sub-waves, the detection area is comprehensively covered, and each detection unit is refined, the detection and monitoring sensitivity of the tiny ceramic abrasives is further improved, the content of the particles in the oil is calculated to obtain the related information of the viscosity of the oil, and the detection capacity of the device is improved.

[0046] Reference to the accompanying drawings Figures 4-6 One of the embodiments is a ring array detection, the ultrasonic detection sensor further comprises a ring-shaped sensor framework 24 matched with the cross section of the oil guide pipe 10, a plurality of groups of the ultrasonic generators 22 and the ultrasonic receivers 23 are arranged in a ring array on the inner wall of the ring-shaped sensor framework 24 and are in close contact with each other, and the ultrasonic generators 22 and the ultrasonic receivers 23 are in contact with the oil. Referring to the accompanying drawings, during detection, a plurality of ultrasonic generators 22 synchronously emit sound waves, the corresponding detection focusing areas cover all areas of the oil flowing through the ultrasonic detection sensor 20, when the sound waves collide with the ceramic abrasives 30, the signals are diffracted or scattered, and then the echo signals are received by the ultrasonic receivers 23, and the content and size of the ceramic abrasives 30 in the oil flowing through the ultrasonic detection sensor 20 are determined by analyzing the echo signals.

[0047] As a further improvement, referring to Fig. 5, in the ring array structure, the arrangement of the ultrasonic generator 22 and the ultrasonic receiver 23 is that the ultrasonic generator 22 and the ultrasonic receiver 23 are respectively arranged on one side, and the opposite ultrasonic generator 22 and the ultrasonic receiver 23 correspond to each other with the center of the ring as the axis.

[0048] Alternatively, referring to Fig. 6, in the ring array structure, the arrangement of the ultrasonic generator 22 and the ultrasonic receiver 23 is that the ultrasonic generator 22 and the ultrasonic receiver 23 are staggered, and the opposite ultrasonic generator 22 and the ultrasonic receiver 23 correspond to each other with the center of the ring as the axis. Figure 6 Alternatively, referring to Fig. 7, in the ring array structure, the arrangement of the ultrasonic generator 22 and the ultrasonic receiver 23 is that the ultrasonic generator 22 and the ultrasonic receiver 23 are staggered, and the opposite ultrasonic generator 22 and the ultrasonic receiver 23 correspond to each other with the center of the ring as the axis.

[0049] Figures 7-10 Alternatively, referring to Fig. 8, another embodiment is that the ultrasonic detection sensor 20 comprises a sensor skeleton 24 which is adapted to the cross section of the oil guide pipe 10, the sensor skeleton 24 is in the shape of a strip grid which can contain oil, and the corresponding ultrasonic generator 22 and the ultrasonic receiver 23 are respectively arranged on two adjacent grid strips 241 to form a multi-stage cascade arrangement. The multi-stage cascade arrangement also has a good overall detection effect. The ultrasonic generator 22 and the ultrasonic receiver 23 are respectively arranged in a linear array or a surface array along the extension direction of the grid strip 241.

[0050] Alternatively, referring to Fig. 9, the sensor skeleton 24 with the strip grid shape forms multiple oil passing channels, and when the oil flows into the sensor skeleton 24, it is divided into multiple streams, and the ultrasonic generator 22 and the ultrasonic receiver 23 on the side wall of the grid strip are used to detect the ceramic abrasion 30 in the oil to form multiple detection channels in a cascade manner, fully cover the detection area, improve the integrity of the detection result, and at the same time, the oil flow is divided by the division and grading manner, and the detection pressure is reduced. The cascade detection structure can reduce the overlapping part of the sound wave detection focusing area compared with the ring array, and effectively reduces the calculation workload in the processing of the detection data. As a further improvement, the surface of the piezoelectric ceramic wafer is coated with an insulating layer, and the outside of the insulating layer is plated with a metal film to form multiple capacitor stages. The insulating layer is coated on the surface of the piezoelectric ceramic wafer, and the metal film layer is further plated on the outer surface of the insulating layer to form multiple capacitor stages, and the abrasion concentration is indirectly measured by using the medium change in the oil, that is, when the number of ceramic abrasion 30 in the oil is relatively large, the capacitance value of the capacitor stage formed by the piezoelectric ceramic wafer changes when passing through the ultrasonic detection sensor 20, and the concentration of the ceramic abrasion 30 in the oil is indirectly obtained by monitoring the change of the capacitance value, and the comprehensive detection and evaluation ability of the invention for the abrasion is improved. Figure 9

[0051] ​​The application also discloses an online engine oil ceramic abrasion ultrasonic detection method.

[0052] The application adopts the ultrasonic transmission method in the oil return system pipeline of the in-flight engine, uses the hindering effect of the ceramic abrasion on the transmission of the sound wave to obtain the relevant information of the ceramic abrasion, and can effectively detect the ceramic abrasion in the oil by the ultrasonic method.

[0053] As a further improvement, the specific detection steps are as follows:

[0054] S1: the ultrasonic detection sensor is used to pre-set and encode the detection energy focusing areas of the corresponding ultrasonic generator and ultrasonic receiver (AA', BB', CC'...I I'), the area of the ultrasonic detection sensor in series on the oil guide pipe is defined as the detection area, and the plurality of focusing areas comprehensively cover the detection area;

[0055] S2: during the detection, the ultrasonic wave generator sends out the sound wave detection signal through the controller, the sound wave detection signal is split into a plurality of sub-waves, the sub-waves are transmitted in the focusing area through the oil, when the ceramic abrasion is encountered, the signal is distorted to generate the scattering wave, and the echo signal is received by the corresponding ultrasonic receiver;

[0056] S3: the echo signal collected in each focusing area is first amplified and processed, the processing mode is noise removal, the echo signal collected in each focusing area is isolated and processed, and the stray signal and the pipe wall echo signal in the focusing area are removed;

[0057] S4: the echo signal after the processing of the previous stage is converted into the analog electric signal, the detected data are transmitted to the analysis display, and the number and size of the ceramic abrasion in each focusing area are calculated by the particle detection model.

[0058] As a further improvement, the data screening of step S3 also includes the elimination of signals detected in the overlapping area between the focus areas. The range of the overlapping area between the focus areas is calculated in advance by simulating the emission of the sound waves by each ultrasonic generator, and is stored in the analysis display. During analysis, the system automatically eliminates the overlapping signals. This avoids repeated calculation of the number of ceramic particles in the oil, and improves the accuracy of the detection.

[0059] As a further improvement, the detection energy focus areas of the corresponding ultrasonic generators and ultrasonic receivers are preset and coded (AA', BB', CC', … I I') in step S1, where A, B, C, D, … I represent the ultrasonic generators, and A', B', C', D', … I' represent the ultrasonic receivers. In a ring array ultrasonic detection, the arrangement of the ultrasonic generators and the ultrasonic receivers can be that the ultrasonic generators correspond to the ultrasonic receivers in an up-down manner, or that the ultrasonic generators and the ultrasonic receivers are staggered. In a multi-stage ultrasonic detection, the arrangement of the ultrasonic generators and the ultrasonic receivers can be that the ultrasonic generators or the ultrasonic receivers are arranged separately in the same column, or that the ultrasonic generators and the ultrasonic receivers are staggered in the same column. The number of ultrasonic receivers and ultrasonic generators can be adjusted.

[0060] As a further improvement, the several ultrasonic generators emit signals synchronously, and the same frequency and waveform of the signal wave is adopted. The scattering angle of the signal wave is adjusted according to the position of the different ultrasonic generators and the preset focus area.

[0061] According to the length of the duration, the ultrasonic waves can be divided into continuous waves and pulse waves. In the present application, the signal wave is a continuous wave, and can also be a pulse wave. In the present embodiment, a pulse wave is adopted, and the vibration duration is limited. The pulse wave can be intermittent, and can be selected according to the flow rate of the oil and other characteristics. The waveform can be adjusted according to the actual detection situation. When the signal wave is a pulse wave, it can be a rectangular wave, a sawtooth wave, a triangular wave, a sharp peak wave, or a step wave. It can also be other waveforms.

[0062] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An on-line engine oil liquid ceramic wear debris ultrasonic detection sensor characterized by, The application discloses an ultrasonic detection sensor for on-line detection of ceramic abrasion particles in an oil system of an aircraft engine. The ultrasonic detection sensor is connected in series to an oil circuit of the oil system, and comprises a sensor shell and a plurality of sets of ultrasonic generators and ultrasonic receivers arranged oppositely in the sensor shell. Each set of ultrasonic generators and ultrasonic receivers corresponds to a detection focusing area, and the sets of ultrasonic generators and ultrasonic receivers are arranged in an array mode. The plurality of detection focusing areas comprehensively cover the whole area of the oil flowing through the ultrasonic detection sensor. Each set of ultrasonic generators and ultrasonic receivers is provided with a plurality of piezoelectric ceramic chips to form a plurality of transmitting / receiving units. The ultrasonic detection sensor further comprises a ring-shaped sensor framework matched with the cross section of an oil guide pipe. The sets of ultrasonic generators and ultrasonic receivers are arranged in a ring array on the inner wall of the sensor framework and are in contact with the oil. Alternatively, the ultrasonic detection sensor comprises a sensor framework matched with the cross section of the oil guide pipe. The sensor framework is in a strip grid shape and can allow the oil to pass through. Corresponding ultrasonic generators and ultrasonic receivers are arranged on two adjacent grid strips respectively to form a multi-stage cascading arrangement.

2. An on-line engine oil liquid ceramic wear debris ultrasonic detection sensor according to claim 1, wherein, In the ring array structure, the ultrasonic generators and ultrasonic receivers are arranged in a single-side mode. The ultrasonic generators and ultrasonic receivers are arranged oppositely with the center of the sensor framework as the axis. Alternatively, the ultrasonic generators and ultrasonic receivers are arranged in a staggered mode. The ultrasonic generators and ultrasonic receivers are arranged oppositely with the center of the sensor framework as the axis.

3. An on-line engine oil liquid ceramic wear debris ultrasonic detection sensor according to claim 1, wherein, The ultrasonic generators and ultrasonic receivers are arranged in an array mode along the extending direction of the grid strips.

4. An on-line engine oil liquid ceramic wear debris ultrasonic detection sensor according to claim 3, wherein, The surface of the piezoelectric ceramic chip is coated with an insulating layer. The outer part of the insulating layer is plated with a metal film to form a plurality of capacitor stages.

5. An on-line engine oil liquid ceramic wear debris ultrasonic detection method, using the ultrasonic detection sensor of any one of claims 1-4 for on-line detection, characterized in that, During detection, the ultrasonic generators generate sound waves which are transmitted to the ultrasonic receivers through the oil. When the oil in the corresponding focusing area contains ceramic abrasion particles, the signal received by the ultrasonic receivers is distorted. The signal received by the ultrasonic receivers is amplified and denoised by a signal processor. The processed signal is analyzed to indirectly evaluate the size and quantity of the abrasion particles in the oil system and predict the remaining life of the aircraft engine bearing.

6. An on-line engine oil liquid ceramic wear debris ultrasonic detection method according to claim 5, wherein, The specific detection steps are as follows: S1: The ultrasonic detection sensor is used to preset and encode the detection energy focusing areas of the corresponding ultrasonic generators and ultrasonic receivers (AA', BB', CC'... II'). The area of the ultrasonic detection sensor connected in series to the oil guide pipe on the oil guide pipe is defined as a detection area, and the plurality of focusing areas comprehensively cover the detection area. S2: During detection, the controller controls the ultrasonic generators to emit sound wave detection signals. The sound wave detection signals are split into a plurality of sub-waves which are transmitted in the focusing areas through the oil. When the ceramic abrasion particles are encountered, the signal is distorted to generate scattered waves which are received by the corresponding ultrasonic receivers. S3: The echo signals collected in each focusing area are first amplified and processed. The processing mode is denoising. The echo signals collected in each focusing area are isolated and processed to remove the stray signals and pipe wall echo signals in the focusing area. S4: the echo signal after the previous step is converted into electric signal, and the detected data is transmitted to the analysis display, and the number and size of the ceramic abrasion in each focus area are calculated through the particle detection model.

7. An on-line engine oil liquid ceramic wear debris ultrasonic detection method according to claim 6, wherein, The data screening of step S3 also includes removing the signals detected by overlapping between the focus areas.

8. An on-line engine oil liquid ceramic wear debris ultrasonic detection method according to claim 7, wherein, The signal waves are emitted by several ultrasonic generators synchronously, and the same frequency and waveform are adopted; the emission angle of the signal waves is adjusted according to the positions of the different ultrasonic generators and the preset focus areas. The signal waves are continuous waves or pulse waves; when the signal waves are pulse waves, the pulse waves are rectangular waves, sawtooth waves, triangular waves, sharp peak waves or step waves.

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