A device, method and circuit for detecting wear particles in lubricating oil

Abstract

The application relates to a lubricating oil abrasive particle detection device, which comprises an electromagnetic detection unit, a capacitive detection unit and a shell. The electromagnetic detection unit comprises a diameter-gradually-changing heterogeneous skeleton, a plurality of excitation coils are coaxially sleeved on the heterogeneous skeleton, and an induction coil is coaxially arranged in the heterogeneous skeleton and is suitable for electromagnetic detection of metal abrasive particles. The capacitive detection unit comprises a support skeleton, a plurality of tooth-shaped polar plates are coaxially and staggeredly arranged on the support skeleton, and the capacitive detection unit is suitable for capacitive detection of non-metal abrasive particles. The shell is arranged outside the electromagnetic detection unit and the capacitive detection unit, a long shaft is coaxially and internally arranged through the shell, and the electromagnetic detection unit and the capacitive detection unit are coaxially and sequentially arranged on the long shaft. When the abrasive particles flow through a detection area, the capacitive detection unit can output a signal reflecting dielectric constant disturbance caused by the abrasive particles in real time, and the electromagnetic detection unit can output a signal reflecting the change of induced voltage when the abrasive particles pass through an alternating magnetic field. After joint analysis of the two types of information, the size and material category of different material abrasive particles can be cooperatively recognized.

Description

Technical Field

[0001] This invention belongs to the field of engine technology and relates to lubricating oil abrasive particles, particularly a detection device, method, and circuit for lubricating oil abrasive particles. Background Technology

[0002] As a core component of an aircraft, the engine needs to operate for extended periods in high-temperature, high-pressure, high-load, and complex and harsh environments. Under prolonged high-speed and high-load conditions, critical components such as bearings and gears inevitably experience wear, generating metallic or non-metallic abrasive particles in the lubrication system. Under complex lubrication conditions, sensors based on a single detection principle can typically only characterize local features of the abrasive particles, making it difficult to simultaneously acquire multi-dimensional information such as particle size, material properties, and response strength. Consequently, these sensors have limitations in terms of abrasive particle identification accuracy, detection completeness, and applicability. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a detection device, method and circuit for lubricating oil abrasive particles with a wide detection range and high identification accuracy.

[0004] To solve the above problems, the technical solution of the present invention is as follows:

[0005] A device for detecting abrasive particles in lubricating oil, comprising:

[0006] The electromagnetic detection unit includes a heterogeneous frame with a gradually changing diameter, several excitation coils coaxially mounted on the heterogeneous frame at intervals, and induction coils coaxially arranged inside the heterogeneous frame, which is suitable for electromagnetic detection of abrasive particles in metal materials.

[0007] The capacitance detection unit includes a support frame with several toothed plates coaxially and alternately arranged on the support frame, which is suitable for capacitance detection of non-metallic abrasive particles.

[0008] The outer casing is located outside the electromagnetic detection unit and the capacitance detection unit. A long axis is coaxially arranged inside the casing, and the electromagnetic detection unit and the capacitance detection unit are coaxially arranged sequentially on the long axis.

[0009] In a further embodiment, a second protective layer is fixedly installed in the middle of the outer casing. The second protective layer divides the internal space of the outer casing into two parts, and an electromagnetic detection unit and a capacitance detection unit are respectively arranged in the two parts.

[0010] In a further embodiment, the heterogeneous skeleton includes a first sub-skeleton and a second sub-skeleton, both of which have gradually increasing diameters, and the ends of the first and second sub-skeletons with the largest diameters are connected together.

[0011] In a further embodiment, a pair of annular plates are coaxially mounted on the support frame. Each pair of annular plates is provided with a number of toothed plates at intervals, and the toothed plates on the pair of annular plates are arranged alternately.

[0012] In a further embodiment, a plurality of limiting blocks are spaced apart on the two end surfaces of the support frame, and the plurality of limiting blocks are respectively disposed between adjacent toothed plates.

[0013] The annular electrode plate is fitted between the limiting block and the end of the support frame.

[0014] A method for detecting abrasive particles in lubricating oil, using a lubricating oil abrasive particle detection device, characterized by comprising the following steps:

[0015] Connect the excitation coil to the excitation signal generator, set the output frequency and excitation level of the excitation signal generator, which is suitable for establishing an alternating excitation field in the electromagnetic detection unit; The weak AC signal output by the induction coil is amplified by the pre-amplifier, synchronously demodulated, amplified by the post-amplifier and filtered to obtain electromagnetic detection data. The capacitance change signal is output through the toothed plates, and the capacitance detection data is obtained after capacitance digital conversion and filtering. Electromagnetic and capacitive detection data are simultaneously sent to a host computer for joint analysis, which is suitable for identifying the size parameters and material type of abrasive particles.

[0016] In a further embodiment, synchronous demodulation employs a balanced demodulation module, using the same frequency signal output by the excitation signal generator as a reference signal. Weak abrasive particle signals are extracted through phase-sensitive detection, and peak value extraction is performed to obtain the induced voltage peak or corresponding characteristic quantity, which is used to acquire electromagnetic detection data.

[0017] In a further embodiment, the capacitance-to-digital conversion uses a capacitance-to-digital conversion chip, which is configured and read by a microcontroller to obtain the capacitance peak value or corresponding characteristic value, which is used to acquire capacitance detection data.

[0018] A detection circuit for lubricating oil abrasive particles, using a lubricating oil abrasive particle detection method, includes:

[0019] The electromagnetic detection branch, whose input end is used to connect to the induction coil and whose output end is used to output electromagnetic detection data, includes a balanced demodulation module, a signal amplifier module, and an adjustable signal filter module connected in sequence.

[0020] The capacitance detection branch includes a capacitance-to-digital conversion circuit and a control and reading circuit. Its input terminal is used to connect to the toothed plate, and its output terminal is used to output capacitance detection data. The power supply unit provides operating power to the electromagnetic detection branch and the capacitance detection branch, respectively. The host computer receives electromagnetic detection data and capacitance detection data respectively, and performs joint analysis.

[0021] In a further embodiment, the balanced demodulation module includes a synchronous demodulation circuit, the signal amplifier module includes a pre-amplifier circuit and a post-amplifier circuit, and the adjustable signal filtering module includes a filtering and conditioning circuit.

[0022] The preamplifier circuit, synchronous demodulation circuit, power amplifier circuit, and filter circuit are connected in sequence.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. This detection device integrates a capacitance detection unit and an electromagnetic detection unit. When abrasive particles flow through the detection area, the capacitance detection unit outputs a signal reflecting the disturbance of the dielectric constant caused by the abrasive particles in real time, while the electromagnetic detection unit simultaneously outputs a signal reflecting the change in the induced voltage generated when the abrasive particles pass through an alternating magnetic field. After joint analysis of these two types of information, the size and material type of abrasive particles of different materials can be collaboratively identified. This method significantly improves detection accuracy and reduces the false negative rate, effectively detecting iron particles larger than 150 micrometers, copper particles larger than 350 micrometers, and non-metallic particles larger than 100 micrometers in oil, achieving broad-spectrum detection of both metallic and non-metallic abrasive particles.

[0025] 2. This detection device integrates a capacitance detection unit composed of toothed plates with an electromagnetic detection unit composed of heterogeneous coils. When abrasive particles pass through the detection area, it can simultaneously acquire dielectric constant disturbance information and induced voltage change information, achieving dual-parameter joint detection. Compared with single-principle sensors, this integrated structure eliminates the need for time-division or position-division measurement, improving detection efficiency and information synchronization.

[0026] 3. This detection device uses a capacitor detection unit consisting of a ring-shaped electrode and a toothed electrode to obtain a relatively uniform electric field by utilizing the edge effect between the toothed electrodes. This results in good response capability to non-metallic abrasive particles and non-ferromagnetic particles (such as copper particles), thus overcoming the defect of electromagnetic detection being insensitive to non-metallic and non-ferromagnetic materials.

[0027] 4. The electromagnetic detection unit in this detection device is composed of heterogeneous coils, which effectively complements the detection of metal abrasive particles (especially ferromagnetic particles). The synergy of these two types of signals improves the ability to distinguish abrasive particles of different materials, enhances detection accuracy and information completeness, and solves the problem of missed detections that arises with a single detection principle.

[0028] 5. This testing device is suitable for online monitoring scenarios under complex lubricating oil conditions. It can expand the types of abrasive particles that can be identified while maintaining system integration and online monitoring capabilities, and boasts advantages such as high speed, high accuracy, low cost, and wide applicability.

[0029] 6. This detection device obtains a uniformly distributed alternating magnetic field by setting excitation coils of different diameters, and uses several staggered toothed plates to utilize the edge effect of capacitance, thereby improving the field uniformity and the accuracy of abrasive particle detection, realizing full-range monitoring of lubricating oil abrasive particles, and effectively reducing the missed detection rate.

[0030] 7. This detection method has advantages such as high speed, high accuracy, low cost, and wide applicability. By detecting and analyzing the information of metal and non-metal particles in the oil, it can quickly, accurately, cost-effectively, and maintenance-free detect contaminants in lubricating grease online, thereby judging the wear condition of mechanical equipment and preventing major failures. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a device for detecting abrasive particles in lubricating oil.

[0032] Figure 2 A schematic diagram of a toothed electrode plate in a device for detecting abrasive particles in lubricating oil;

[0033] Figure 3 A schematic diagram of a heterogeneous skeleton for a device for detecting abrasive particles in lubricating oil;

[0034] Figure 4 A schematic diagram of the support frame for a device for detecting abrasive particles in lubricating oil;

[0035] Figure 5 This is one of the schematic diagrams of a detection circuit for abrasive particles in lubricating oil;

[0036] Figure 6 This is a second schematic diagram of a detection circuit for lubricating oil abrasive particles;

[0037] Figure 7(a) is one of the schematic diagrams of the capacitance detection unit results of a method for detecting abrasive particles in lubricating oil;

[0038] Figure 7(b) is a schematic diagram of the results of the capacitance detection unit in a method for detecting abrasive particles in lubricating oil (Part 2).

[0039] Figure 8 This is a schematic diagram of the electromagnetic detection unit results for a method of detecting abrasive particles in lubricating oil.

[0040] Figure 9 This is a flowchart of a method for detecting abrasive particles in lubricating oil;

[0041] Figure 10 This is a block diagram of a detection circuit for abrasive particles in lubricating oil.

[0042] In the diagram: 1. Excitation coil; 2. Induction coil; 3. First protective layer; 4. Second protective layer; 5. Heterogeneous frame; 6. Outer shell; 7. Lubricating oil pipeline; 8. Annular electrode plate; 9. Toothed electrode plate; 10. First sub-frame; 11. Second sub-frame; 12. Support frame; 13. First side groove; 14. First middle groove; 15. Second middle groove; 16. Third middle groove; 17. Fourth middle groove; 18. Fifth middle groove; 19. Sixth middle groove; 20. Second side groove; 21. Coil channel; 22. First support frame; 23. Second support frame; 24. Limiting block; 25. Cylindrical frame. Detailed Implementation

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0044] Aero engines consist of multiple critical components and systems, with maintenance costs accounting for over 50% of their total lifecycle value. As a core component of an aircraft, the engine must operate for extended periods in high-temperature, high-pressure, high-load, and complex and harsh environments. Under prolonged high-speed, high-load conditions, critical components such as bearings and gears inevitably experience wear, generating metallic or non-metallic abrasive particles in the lubrication system. Extensive engineering experience and accident statistics indicate that approximately 40% of major aircraft accidents are related to engine failure, and over 80% of these failures are caused by abnormal engine wear. The abrasive particles generated during the wear process circulate within the engine via the lubrication system, carrying a wealth of important information reflecting the engine's wear condition and directly characterizing the wear status and evolution trend of components. Therefore, online lubrication particle monitoring technology has become one of the important technical approaches for achieving engine health management (PHM) and predictive maintenance.

[0045] Existing capacitance sensors have strong anti-interference capabilities and are universally applicable to non-ferromagnetic materials, enabling them to detect changes in dielectric constant caused by abrasive particles. However, their sensitivity remains limited. Electromagnetic sensors have better sensitivity and can detect changes in induced voltage generated by metal abrasive particles. However, the accuracy of the detection results is limited, and the coverage of abrasive particle information is insufficient under a single principle.

[0046] In complex lubricating oil operating conditions, sensors based on a single detection principle can typically only characterize local features of abrasive particles, making it difficult to simultaneously acquire multi-dimensional information such as particle size, material properties, and response strength. Therefore, they have limitations in terms of abrasive particle identification accuracy, detection completeness, and applicability. Integrating sensing units with different detection mechanisms can leverage their respective response advantages to different particle materials to create a complementary effect. This approach maintains online monitoring capabilities while improving material identification, detection accuracy, and information completeness, making it more suitable for online monitoring of lubricating oil abrasive particles under complex operating conditions.

[0047] For fusion sensors, abrasive particles passing through the detection area simultaneously cause changes in dielectric characteristics and electromagnetic induction response. Specifically, the signal output from the capacitance unit reflects the dielectric constant disturbance caused by the abrasive particles, while the signal output from the electromagnetic unit reflects the induced voltage change generated when the abrasive particles pass through an alternating magnetic field. Joint analysis of these two types of signals allows for the coordinated identification of abrasive particle size and material type, thus providing a more complete monitoring basis for determining engine wear conditions.

[0048] Example 1:

[0049] A device for detecting abrasive particles in lubricating oil, such as Figures 1 to 4As shown, the system includes an oil piping 7, a housing 6, an electromagnetic detection unit, and a capacitance detection unit. The housing 6 is a horizontally positioned cylindrical structure, with the oil piping 7 coaxially threaded through its center. The oil piping 7 runs horizontally through the housing 6. The electromagnetic detection unit and the capacitance detection unit are sequentially fixed inside the housing 6 to shield against external electromagnetic noise interference. The signal output by the capacitance detection unit reflects the dielectric constant disturbance caused by abrasive particles, while the signal output by the electromagnetic detection unit reflects the induced voltage change when abrasive particles pass through an alternating magnetic field. Joint analysis of these two types of information enables collaborative identification of the size and material type of abrasive particles of different materials, improving detection accuracy and reducing the false negative rate. It can detect iron particles larger than 150 micrometers, copper particles larger than 350 micrometers, and non-metallic particles larger than 100 micrometers in the oil. The outer casing 6 has a first protective layer 3 fixedly installed on both sides. The outer casing 6 is divided into two sections, which are connected by threads. During threaded installation, a second protective layer 4 is fixedly installed on the inner end of the inner section to prevent collision deformation or frictional loss caused by vibration. Both the first protective layer 3 and the second protective layer 4 are circular structures and perpendicular to the inner wall of the outer casing 6. The electromagnetic detection unit and the capacitance detection unit are located within the two sections of the outer casing 6, respectively. Specifically, the first protective layer 3 is made of polytetrafluoroethylene (PTFE); the outer casing 6 and the second protective layer 4 are both made of a high-magnetic-flux nickel-iron alloy.

[0050] like Figure 1 , Figure 4 As shown, the capacitance detection unit includes: a support frame 12 coaxially mounted on the lubricating oil pipeline 7, the support frame 12 matching the outer wall of the lubricating oil pipeline 7; the support frame 12 is provided with an axial groove and a lead wire port to achieve stable integration with the lubricating oil pipeline 7 and form a lead wire arrangement space. The support frame 12 includes a cylindrical frame 25 and a first support frame 22 and a second support frame 23. The diameter of the cylindrical frame 25 is larger than the diameter of the lubricating oil pipeline 7. The first support frame 22 and the second support frame 23 are fixedly installed at both ends of the cylindrical frame 25, respectively. The first support frame 22 and the second support frame 23 are both annular structures, and the inner diameters of the first support frame 22 and the second support frame 23 correspond to the diameter of the lubricating oil pipeline 7. The outer diameters of the first support frame 22 and the second support frame 23 are both larger than the diameter of the cylindrical frame 25. Several protruding limiting blocks 24 are formed on the outer surface of both ends of the cylindrical frame 25.

[0051] like Figure 1 , Figure 2As shown, a pair of annular electrode plates 8 are coaxially mounted on the support frame 12, one of which is a driving electrode and the other is a sensing electrode. Several toothed electrode plates 9 are spaced apart on the pair of annular electrode plates 8, and these toothed electrode plates 9 are staggered. This arrangement aims to change the concentrated electric field distribution in ordinary annular electrodes or single arc-shaped electrodes, allowing the capacitance detection area to be divided into multiple corresponding edge electric field sensitive areas around the lubricating oil pipeline 7. Since abrasive particles changing the dielectric properties of the local oil medium when passing through the capacitance detection area further alters the induced capacitance between the electrode plates, the edge electric field formed between the toothed electrode plates 9 and adjacent annular electrode plates 8 enhances the response to such dielectric disturbances. When several toothed electrode plates 9 are inserted together, gaps are left between adjacent toothed electrode plates 9 to utilize the edge effect. Several limiting blocks 24 on the support frame 12 are located in several gaps, and the pair of annular electrode plates 8 are respectively clamped between the limiting blocks 24 and the first support frame 22 and the second support frame 23, suitable for fixing the pair of annular electrode plates 8. Preferably, the width of the limiting block 24 corresponds to the width of the adjacent toothed electrode 9, which is suitable for firmly fixing several toothed electrode 9s and preventing the pair of annular electrode 8s and several toothed electrode 9s from shifting, so as to maintain the electrode gap, achieve stable integration with the lubricating oil pipeline 7, and form a lead wire arrangement space; the number of limiting blocks 24 corresponds to the number of toothed electrode 9s. Further, the toothed electrode 9 has an arc-shaped structure and the circumferential coverage angle of the toothed electrode 9 is 60 degrees, so that the potential distribution in the detection area is more uniform, forming a capacitance detection unit; there are a total of four toothed electrode 9s; the toothed electrode 9s are made of highly conductive copper sheets. The staggered toothed electrode 9s make the sensitive area between the electrodes no longer concentrated in a single direction, but divided into multiple fan-shaped detection areas along the cross section of the lubricating oil pipeline 7, so that the abrasive particles can induce a relatively stable capacitance response when passing through different radial positions. Therefore, the interleaved structure can improve the circumferential coverage and distribution uniformity of the capacitance detection field while maintaining the integrated form of the sensor pipeline, reduce the influence of the difference in the movement trajectory of abrasive particles on the amplitude of the capacitance signal, thereby improving the detection sensitivity, consistency and recognition stability of the capacitance detection unit for non-metallic abrasive particles and non-ferromagnetic metallic abrasive particles.

[0052] like Figure 1 , Figure 3As shown, the electromagnetic detection unit includes: a heterogeneous frame 5 coaxially mounted on an oil pipeline 7; several excitation coils 1 coaxially mounted on the heterogeneous frame 5; and an induction coil 2 disposed inside the heterogeneous frame 5. The induction coil 2 is coaxially mounted on the oil pipeline 7 and located at the center of the base of the oil pipeline 7. Specifically, the oil pipeline 7 has a groove suitable for accommodating the induction coil 2; both the excitation coil 1 and the induction coil 2 are made of copper core enameled wire, and the number of turns of the excitation coil 1 is greater than the number of turns of the induction coil 2. The heterogeneous frame 5 includes a first sub-frame 10 and a second sub-frame 11. The diameters of the first sub-frame 10 and the second sub-frame 11 gradually increase from one end to the other. The first sub-frame 10 and the second sub-frame 11 are mounted together opposite each other, that is, the ends with the largest diameters of the first sub-frame 10 and the second sub-frame 11 are mounted together. An opening is provided at the connection end of the first sub-frame 10 and the second sub-frame 11, forming a coil channel 21. The first sub-frame 10 and the second sub-frame 11 have first side grooves 13 and second side grooves 20 respectively at their smallest diameter ends. The first sub-frame 10 has first central grooves 14, second central grooves 15, and third central grooves 16 with successively increasing diameters. The second sub-frame 11 has fourth central grooves 17, fifth central grooves 18, and sixth central grooves 19 with successively decreasing diameters. Excitation coils 1 are coaxially mounted in the first side grooves 13, second side grooves 20, first central grooves 14, second central grooves 15, third central grooves 16, fourth central grooves 17, fifth central grooves 18, and sixth central grooves 19. Each groove wall is provided with a lead wire opening. The excitation coils 1 in the first middle slot 14, the second middle slot 15, the third middle slot 16, the fourth middle slot 17, the fifth middle slot 18, and the sixth middle slot 19 are connected in series with the excitation coils 1 in the first side slot 13 and the second side slot 20, respectively. The winding direction of the excitation coils 1 in the first middle slot 14, the second middle slot 15, the third middle slot 16, the fourth middle slot 17, the fifth middle slot 18, and the sixth middle slot 19 is the same, while the winding direction of the excitation coils 1 in the first side slot 13 and the second side slot 20 is opposite to that of the excitation coils 1 in the first middle slot 14, the second middle slot 15, the third middle slot 16, the fourth middle slot 17, the fifth middle slot 18, and the sixth middle slot 19.

[0053] like Figure 1 , Figure 3As shown, the diameters of the first side groove 13 and the second side groove 20 are larger than those of the first middle groove 14 and the sixth middle groove 19, while the diameters of the first side groove 13 and the second side groove 20 are smaller than those of the second middle groove 15 and the fifth middle groove 18. The inner diameter of the lubricating oil pipeline 7 is set as the reference dimension D; the inner diameter of the annular electrode plate 8 is 2D, the outer diameter is 2.2D, and the width is 0.1D; the length of the toothed electrode plate 9 is 1.6D, the circumferential coverage angle of the toothed electrode plate 9 is 60 degrees, and the distance between the toothed electrode plates 9 on one annular electrode plate 8 and another annular electrode plate 8 is 0.1D; the inner diameter of the cylindrical frame 25 is 0.9D, the outer diameter is 1D, and the width is 2.1D; the width of the limiting block 24 is 0.1D; the width of the sixth middle groove 19 is 0.4D, and the diameters of the first middle groove 14, the second middle groove 15, and the fifth middle groove 18 are smaller than those of the first middle groove 14 and the sixth middle groove 19. The groove lengths of grooves 15, 16, 17, 18, and 19 are all 0.4D. Among them, the inner diameter of the groove in the first groove 14 is 1.4D and the outer diameter is 2D; the inner diameter of the groove in the second groove 15 is 1.3D and the outer diameter is 2D; the inner diameter of the groove in the third groove 16 is 2D and the outer diameter is 2.7D; and the inner diameter of the groove in the fourth groove 17 is 2.4D and the outer diameter is 3D. Since the configurations of the first sub-framework 10 and the second sub-framework 11 are completely identical, the remaining groove dimensions are set accordingly. From the edge to the center, the thicknesses of the walls of the first central groove 14, the second central groove 15, the third central groove 16, the fourth central groove 17, the fifth central groove 18, and the sixth central groove 19 are 0.1D, 0.15D, 0.1D, 0.15D, and 0.1D, respectively; the inner diameter of the second protective layer 4 is 1.2D, the outer diameter is 3.2D, and the width is 0.3D; the inner diameter of the first protective layer 3 is 1.2D, the outer diameter is 3.2D, and the width is 0.2D; the inner diameter of the outer shell 6 is 3.2D, and the outer diameter is 3.6D.

[0054] Example 2:

[0055] A detection circuit for abrasive particles in lubricating oil, such as Figure 5 , Figure 6 , Figure 10 As shown, the system includes a 3V linear power supply, a DDS excitation signal generator, a sensor unit, a capacitance detection branch, an electromagnetic detection branch, and a host computer. Specifically, the capacitance detection branch mainly includes a capacitance-to-digital converter chip and an STM32F103C8T6 microcontroller, which uses the capacitance-to-digital converter chip to detect weak capacitance signals. The electromagnetic detection branch contains three sub-modules: a balanced demodulation module, a signal amplifier module, and an adjustable signal filter module.

[0056] like Figure 5As shown, the capacitance detection branch includes a PCAP01AD capacitance-to-digital converter circuit, an STM32F103C8T6 control and reading circuit, and power supply, reset, and decoupling circuits that work in conjunction with it. The capacitance change signal output from the toothed plate 9 is input to the PCAP01AD, which is used to perform digital conversion of the capacitance signal and provide excitation voltage. The STM32F103C8T6 is connected to the PCAP01AD through a serial interface, which includes at least a clock line, data input / output lines, and a chip select control line. The STM32F103C8T6 is used to perform configuration control of the PCAP01AD, read the conversion results, and finally upload the data to the host computer.

[0057] like Figure 6 As shown, the electromagnetic detection branch includes a pre-amplifier circuit, an AD630 synchronous demodulation circuit, an AD8421 post-amplifier circuit, and a low-pass filter and signal conditioning circuit composed of LF353. The weak AC signal output from induction coil 2 is first fed into the pre-amplifier for preliminary conditioning and amplification. The amplified detection signal is then fed into the AD630. The excitation signal generator DDS provides a reference signal with the same frequency as the excitation coil 1 and is fed into the AD630 to complete synchronous demodulation. The demodulated signal output from the AD630 is sent to the AD8421 for post-amplification, and then fed into the filter and conditioning circuit composed of LF353. The conditioned electromagnetic detection signal is then output to the host computer.

[0058] The power supply unit provides operating power to the capacitance detection branch and the electromagnetic detection branch respectively. The PCAP01AD and STM32F103C8T6 receive stable power through a voltage regulation and decoupling network, while the preamplifier circuit, AD630, AD8421, and LF353 receive operating voltage through a dual power supply network, thus ensuring the synchronous and stable operation of the two detection branches. During actual testing, the host computer receives capacitance detection data uploaded from the STM32F103C8T6 and electromagnetic detection data output from the electromagnetic detection branch, and performs timing correspondence and joint analysis on the two types of signals to identify different types of abrasive particles in the oil.

[0059] The circuit setup includes the following steps:

[0060] (1) Set the output frequency and excitation level of the excitation signal generator DDS according to the working condition of the oil to be tested, and connect its output terminal to the excitation coil 1 to establish an alternating excitation field in the detection area;

[0061] (2) Install the sensor unit in the lubricating oil pipeline 7, so that both ends of the sensor unit are connected to the lubricating oil pipeline 7, and arrange the toothed electrode plate 9, the excitation coil 1 and the induction coil 2 in the same detection area.

[0062] (3) Connect the +5V power supply and GND to the VDD and GND terminals of STM32F103C8T6 and PCAP01AD respectively, and connect the V+, V- or +VS, -VS working voltages to the preamplifier, AD630, AD8421 and LF353 respectively to complete the system power-on preparation.

[0063] (4) The weak AC signal output by the induction coil 2 is sent to the input terminal of the pre-amplifier through the input node IN to perform preliminary amplification and conditioning of the electromagnetic detection signal;

[0064] (5) Send the detection signal output from the preamplifier to the signal input channel of AD630, and send the synchronous reference signal output from the excitation signal generator DDS to the reference input channel of AD630, so that AD630 can complete synchronous demodulation and output the demodulated signal from VOUT terminal 27;

[0065] (6) The output of VOUT terminal 28 of AD630 is sent to port 29 of AD8421 for amplification. Then, the output of AD8421 via port 30 is sent to the filter circuit composed of 2IN+ terminal 31 and 2IN- terminal 32 of LF353. The OUT output is formed by 2OUT terminal 33 of LF353 to obtain electromagnetic detection data.

[0066] (7) Connect the capacitance change signal output by the toothed electrode plate 9 to the capacitance detection terminal of PCAP01AD so that the dielectric disturbance caused by the wear particles in the oil is converted into the capacitance change signal to be measured.

[0067] (8) Connect the MOSI terminal 34, MISO terminal 35, SCK terminal 36 and SSN terminal 37 of PCAP01AD to the PA7 terminal 38, PA6 terminal 39, PA5 terminal 40 and PA041 terminal of STM32F103C8T6 respectively.

[0068] (9) The STM32F103C8T6 initializes and configures the PCAP01AD and reads the conversion results; during the detection process, the electromagnetic detection branch and the capacitance detection branch work in parallel, and the electromagnetic detection data output by 2OUT terminal 33 and the capacitance detection data uploaded by STM32F103C8T6 are synchronously sent to the host computer.

[0069] Example 3:

[0070] A method for detecting abrasive particles in lubricating oil, as shown in Figures 7 to 8. Figure 9 As shown, it includes the following steps:

[0071] Step S101: Connect excitation coil 1 to the excitation signal generator, and set the output frequency and excitation level of the excitation signal generator to establish an alternating excitation field within the electromagnetic detection unit.

[0072] Connect the excitation coil 1 to the excitation signal generator, and set the output frequency and excitation level of the excitation signal generator. At this time, the electromagnetic detection unit forms an induced voltage signal link. The voltage signal link uses two input signals: one is the sensor detection signal, and the other is the reference signal. Apply a DC voltage with a frequency of 100KHz and a level of 5V to the excitation coil 1 located in the first side slot 13 and the second side slot 20.

[0073] Step S103: A weak AC signal is output through induction coil 2, which is then amplified, synchronized, amplified, and filtered to obtain electromagnetic detection data.

[0074] The induced voltage signal link is based on a balanced demodulation module. It extracts weak abrasive particle signals through phase-sensitive detection, and obtains the induced voltage peak value or corresponding characteristic quantity after filtering, amplification and peak extraction.

[0075] Step S105: The capacitance change signal is output through the toothed electrode 9, and after capacitance digital conversion and filtering, the capacitance detection data is obtained.

[0076] The capacitance detection unit forms a capacitance signal link. This link uses the capacitance change signal output from the toothed electrode 9. Using a capacitance digital conversion module as its core, it obtains the capacitance peak value or corresponding characteristic quantity through capacitance digital conversion, filtering, and feature extraction. Based on the induced voltage peak value or corresponding characteristic quantity and the capacitance peak value or corresponding characteristic quantity, a correspondence is established between the abrasive particle size parameters and material type, and the induced voltage and capacitance values. A DC voltage with a frequency of 50Hz and a level of 3V is applied to the toothed electrode 9.

[0077] Step S107: Simultaneously send the electromagnetic detection data and capacitance detection data to the host computer for joint analysis, suitable for identifying the size parameters and material type of abrasive particles.

[0078] When both the electromagnetic detection signal and the capacitance detection signal exhibit upward pulse characteristics, they are identified as ferromagnetic metal abrasive particles; when the electromagnetic detection signal exhibits downward pulses while the capacitance detection signal exhibits upward pulses, they are identified as non-ferromagnetic metal abrasive particles; when the electromagnetic detection branch has no obvious pulses while the capacitance detection branch outputs upward pulses, they are identified as non-metallic abrasive particles, thereby achieving joint identification of abrasive particles in the oil.

[0079] In this embodiment of the invention, the detection results of the abrasive particle lower limit are shown in Figure 7, where Figure 7(a) shows the detection results of iron abrasive particles and Figure 7(b) shows the detection results of copper abrasive particles; the accuracy results of the oil detection system are as follows: Figure 8As shown, the detection method based on the hybrid detection principle of dielectric constant and electromagnetic induction in this embodiment of the invention can detect iron particles with a diameter of more than 150 micrometers, copper particles with a diameter of more than 350 micrometers, and non-metallic particles with a diameter of more than 100 micrometers in oil, and the accuracy of the detection results is as high as 96.05%.

[0080] The present invention also provides a computer device, including a processor component comprising at least one processor; a storage component comprising a memory; program instructions comprising a computer program stored in the memory; the processor component being configured to read and execute the program instructions in the storage unit to implement steps S101 to S107.

[0081] The present invention provides a computer program product including computer-executable instructions, which, when executed on a processor of an electronic device, enable the electronic device to perform steps S101 to S107.

[0082] This invention also provides a computer-readable storage medium storing computer program instructions. The storage medium includes non-volatile memory (e.g., solid-state drives, flash memory) or temporary storage media (e.g., memory cache). The computer-readable storage medium stores an independent product, which implements steps S101 to S107 in the form of software functional units. Essentially, the part of the technical solution of this invention that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute steps S101 to S107. The aforementioned storage medium includes, but is not limited to, semiconductor memories (e.g., ROM, RAM, Flash), magnetic storage media (e.g., hard disks, magnetic tapes), optical storage media (e.g., CDs, DVDs), and other physical storage devices capable of carrying program code (e.g., USB flash drives, portable hard drives, etc.).

[0083] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A device for detecting abrasive particles in lubricating oil, characterized in that, include: The electromagnetic detection unit includes a heterogeneous frame (5) with a gradually changing diameter. Several excitation coils (1) are coaxially mounted on the heterogeneous frame (5) at intervals. An induction coil (2) is coaxially arranged inside the heterogeneous frame (5), which is suitable for electromagnetic detection of abrasive particles of metal materials. The capacitance detection unit includes a support frame (12), on which several toothed plates (9) are coaxially and alternately arranged, which is suitable for capacitance detection of non-metallic abrasive particles. The outer casing (6) is located outside the electromagnetic detection unit and the capacitance detection unit, and the inner casing is coaxially connected to the lubricating oil pipeline (7). The electromagnetic detection unit and the capacitance detection unit are coaxially connected to the lubricating oil pipeline (7) in sequence.

2. The device for detecting abrasive particles in lubricating oil according to claim 1, characterized in that, A second protective layer (4) is fixedly installed in the middle of the outer shell (6). The second protective layer (4) divides the internal space of the outer shell (6) into two parts, and the electromagnetic detection unit and the capacitance detection unit are respectively arranged in the two parts.

3. The device for detecting abrasive particles in lubricating oil according to claim 2, characterized in that, The heterogeneous skeleton (5) includes a first sub-skeleton (10) and a second sub-skeleton (11). The diameters of the first sub-skeleton (10) and the second sub-skeleton (11) gradually increase, and the ends of the first sub-skeleton (10) and the second sub-skeleton (11) with the largest diameters are connected together.

4. The device for detecting abrasive particles in lubricating oil according to claim 3, characterized in that, A pair of annular plates (8) are coaxially mounted on the support frame (12). Each pair of annular plates (8) is provided with a number of toothed plates (9) spaced apart. The number of toothed plates (9) on the pair of annular plates (8) are arranged alternately together.

5. The device for detecting abrasive particles in lubricating oil according to claim 4, characterized in that, The two ends of the support frame (12) are provided with a plurality of limiting blocks (24) spaced apart, and the plurality of limiting blocks (24) are respectively arranged between adjacent toothed pole plates (9). The annular electrode plate (8) is fitted between the limiting block (24) and the end of the supporting frame (12).

6. A method for detecting abrasive particles in lubricating oil, comprising using the detection apparatus for abrasive particles in lubricating oil as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Connect the excitation coil (1) to the excitation signal generator, and set the output frequency and excitation level of the excitation signal generator to establish an alternating excitation field in the electromagnetic detection unit; The weak AC signal output by the induction coil (2) is amplified by the pre-amplifier, synchronous demodulated, amplified by the post-amplifier and filtered to obtain electromagnetic detection data; The capacitance change signal is output through the toothed plate (9), and the capacitance detection data is obtained after capacitance digital conversion and filtering. The electromagnetic detection data and the capacitance detection data are simultaneously sent to the host computer for joint analysis, which is suitable for identifying the size parameters and material type of abrasive particles.

7. The device for detecting abrasive particles in lubricating oil according to claim 6, characterized in that, The synchronous demodulation adopts a balanced demodulation module, using the same frequency signal output by the excitation signal generator as a reference signal, extracting weak abrasive particle signals through phase-sensitive detection, and obtaining the induced voltage peak value or corresponding characteristic quantity through peak extraction, which is used to acquire the electromagnetic detection data.

8. The device for detecting abrasive particles in lubricating oil according to claim 7, characterized in that, The capacitance-to-digital conversion uses a capacitance-to-digital conversion chip, which is configured and read by a microcontroller to obtain the capacitance peak value or corresponding characteristic value, which is used to acquire the capacitance detection data.

9. A detection circuit for lubricating oil abrasive particles, wherein the detection is performed using the lubricating oil abrasive particle detection method as described in any one of claims 6 to 8, characterized in that, include: The electromagnetic detection branch has an input end for connecting to the induction coil (2) and an output end for outputting electromagnetic detection data, including a balanced demodulation module, a signal amplifier module, and an adjustable signal filter module connected in sequence. The capacitance detection branch includes a capacitance digital conversion circuit and a control reading circuit. Its input end is used to connect to the toothed plate (9), and its output end is used to output capacitance detection data. The power supply unit provides operating power to the electromagnetic detection branch and the capacitance detection branch, respectively. The host computer receives the electromagnetic detection data and the capacitance detection data respectively, and performs joint analysis.

10. The detection circuit for lubricating oil abrasive particles according to claim 9, characterized in that, The balanced demodulation module includes a synchronous demodulation circuit, the signal amplifier module includes a pre-amplifier circuit and a post-amplifier circuit, and the adjustable signal filtering module includes a filtering and conditioning circuit. The preamplifier circuit, the synchronous demodulation circuit, the postamplifier circuit, and the filter and conditioning circuit are connected in sequence.

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