A detection device and method for a transmission stability multi-stage gearbox

Abstract

The present application relates to the technical fields of gear box state detection, in particular to a detection device and method for transmission stability multi-stage gear box, which comprises a fault feature extraction assembly as the core part of intelligent sensor, the fault feature extraction assembly contains an insulating carrier, a signal pickup coil wound on the insulating carrier, a detection sensitivity gain unit located at the upstream, the detection sensitivity gain unit is provided with a rectification channel for restraining the dispersed wear products to the insulating carrier; an adaptive stabilizer is arranged around the periphery of the fault feature extraction assembly and forms a flow bypass, the adaptive stabilizer responds to the fluid pressure fluctuation of the monitoring environment and performs axial compensation displacement. The present application realizes the oil bypassing and non-bypassing of abrasive particles by fluid acceleration and inertial separation, when the sleeve pressure sensing opens the bypass discharge oil, the high momentum abrasive particles are shot into the central detection area by using the inertial difference, so as to realize the oil bypassing and non-bypassing of abrasive particles, and ensure the accurate capture of weak fault features under all working conditions.

Description

Technical Field

[0001] This invention relates to the field of gearbox condition detection technology, specifically to a detection device and method for a multi-stage gearbox with transmission stability. Background Technology

[0002] In the field of full life-cycle health management for large wind power, ocean-going vessels, and heavy mining equipment, monitoring the structural integrity of the internal moving pairs of the transmission system is crucial to ensuring the safe operation of the equipment. As a core transmission component, the spalling material generated by the internal components of the gearbox in the early stages of fatigue failure is an important fault characteristic indicating the mechanical operating condition. Current technologies often use online condition monitoring systems to capture these fault characteristics in real time to assess the remaining lifespan of the equipment. Among these, wear condition monitoring units based on the principle of electromagnetic induction are widely used. They sense abnormal wear products flowing through the monitoring channel by exciting a magnetic field, converting mechanical damage into an electrical signal output, thereby achieving non-invasive diagnosis of the transmission chain's health status. To ensure the signal-to-noise ratio of the fault signal, the monitoring system is usually equipped with electromagnetic shielding measures to suppress the interference of environmental noise on the extraction of weak fault characteristics. As the core hardware of the monitoring system, high-performance intelligent sensors play a vital role in capturing very early signs of mechanical degradation.

[0003] To achieve effective early warning of subtle faults (such as the initiation signal of pitting corrosion at the microscopic scale), existing diagnostic technologies primarily focus on improving the signal pickup sensitivity of monitoring units. According to electromagnetic field theory, monitoring sensitivity depends on the signal coupling efficiency of the fault sample within the detection area. Therefore, the conventional technological evolution path involves limiting the cross-sectional size of the sampling channel to increase the concentration of fault features per unit volume, thereby amplifying the response amplitude of subtle damage signals. For example, existing high-sensitivity monitoring devices often employ sampling channels with micro-apertures, attempting to achieve precise capture of minute fault features under ideal experimental conditions.

[0004] However, in complex industrial field diagnostic environments, the above design faces a contradiction between data acquisition continuity and monitoring system robustness: especially when the device under test (DUT) experiences variable operating conditions (such as high-damping media environments during cold starts or high-throughput sampling requirements during full-speed operation), the sampling back pressure of the micro-sampling channel can rise sharply. To avoid overloading the sampling loop and affecting the normal operation of the DUT, engineering specifications require a protective shunt mechanism to be installed in parallel next to the monitoring unit. When environmental parameters fluctuate or samples accumulate in the sampling channel, the shunt mechanism will be passively opened under differential pressure, causing the medium carrying critical fault information to flow directly through the bypass and escape from the effective monitoring area. This sampling bypass phenomenon can cause the diagnostic system to fall into a "signal blind zone," meaning that the monitoring terminal displays that the equipment status is normal, but the characteristic data reflecting serious equipment faults are not actually captured by the system, resulting in distorted diagnostic conclusions and the risk of unplanned downtime.

[0005] Therefore, a detection device and method for the transmission stability of a multi-stage gearbox are proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a detection device and method for the transmission stability of a multi-stage gearbox. This invention solves the signal blind zone problem caused by the escape of abrasive particles due to bypass pressure relief in high-sensitivity monitoring. Through fluid acceleration and inertial sorting mechanism, when the sleeve pressure is activated to open the bypass and release oil, the high momentum abrasive particles are injected into the central detection area by the inertial difference, thereby achieving oil bypass but not abrasive particle bypass, ensuring accurate capture of weak fault characteristics under all working conditions.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A device for detecting the transmission stability of a multi-stage gearbox includes a fault feature extraction component, which is the core component of an intelligent sensor and independent of the gearbox transmission link. The fault feature extraction component includes an insulating carrier defining a precision sampling channel and a signal pickup coil wound on the insulating carrier. The signal pickup coil is used to capture electromagnetic disturbances caused by particles passing through the insulating carrier in real time. In conjunction with the rectification effect of the upstream, it gathers particles that were originally dispersed in the wide flow channel, overcoming the defect of particle signals being averaged and submerged due to the large pipe diameter in traditional bypass structures. This allows the device to effectively capture weak electromagnetic disturbances caused by early micro-pitting corrosion, thus improving detection sensitivity.

[0008] The detection sensitivity gain unit located upstream of the fault feature extraction component has a rectifier channel that constrains dispersed abnormal wear products to the insulating carrier. Even when the downstream adaptive stabilizer opens the bypass discharge, the high-momentum abrasive particles cannot follow the direction of the light oil due to inertia, but instead maintain a ballistic linear motion and are constrained into the insulating carrier. In this way, the fluid bypasses but the wear particles do not, thereby eliminating the detection blind zone under high viscosity or high flow conditions and improving the capture rate of wear particles under all operating conditions.

[0009] An adaptive stabilizer is arranged around the fault feature extraction component to form a flow bypass. The adaptive stabilizer performs axial compensation displacement in response to fluid pressure fluctuations in the monitored environment. When the pressure exceeds a threshold, the adaptive stabilizer automatically moves axially to open the bypass, which prevents damage to the internal flow channel of the sensor due to excessive back pressure and avoids the risk of gearbox lubrication interruption caused by sensor flow resistance. No additional electronic control actuator is required, which improves the reliability of the system.

[0010] Preferably, the inner wall of the rectifying channel is constructed as a streamlined curved surface with a continuously decreasing cross-sectional area along the fluid flow direction, and the outlet section of the rectifying channel is constructed as a straight cylindrical structure with a constant cross-section. The streamlined curved surface can eliminate fluid boundary layer separation and prevent turbulent vortices that interfere with the trajectory of abrasive particles from being generated at the inlet. The straight cylindrical structure of the outlet section is used to stabilize the velocity vector direction of the abrasive particles after they are accelerated, ensuring that the abrasive particles are injected into the insulating carrier in a state parallel to the central axis, thereby maximizing the cutting efficiency of the magnetic flux and making the amplitude of the induced electromotive force reach the theoretical maximum value.

[0011] Preferably, the inlet end of the rectifier channel is provided with pre-rectifier ribs distributed radially, and the flow-facing surface of the pre-rectifier ribs is constructed into a knife-edge wedge structure; the radial ribs can pre-crush large-sized bubbles mixed in the fluid, preventing bubbles from entering the signal pickup area and causing dielectric constant change noise, and the knife-edge wedge structure can reduce the impact resistance when the fluid enters, avoiding the formation of a local high-pressure stagnation zone at the inlet; at the same time, it can eliminate the swirling component generated by the fluid during pipeline transportation, prevent particles from being thrown towards the pipe wall due to centrifugal force, and ensure that all particles converge on the axis line to enter the insulating carrier.

[0012] Preferably, the adaptive stabilizer includes a hollow sleeve and an elastic element that provides a reset force for the sleeve. A sliding guide pair with a micro-gap fit is formed between the inner circumferential surface of the sleeve and the outer surface of the insulating carrier. The liquid film formed by the micro-gap fit provides radial support to prevent the adaptive stabilizer from deflecting or jamming during movement. Furthermore, the viscous damping characteristics of the liquid film can absorb the mechanical vibration caused by high-frequency pressure pulsation, thereby improving the smoothness of the movement process.

[0013] Preferably, the flow bypass is configured as an involute structure, and the opening area of ​​the flow bypass gradually increases along the oil flow direction; the involute design makes the bypass flow rate and axial displacement nonlinear, providing fine micro-flow adjustment in the initial stage of opening and preventing a sudden drop in system pressure; the gradually increasing opening shape can guide the fluid to smoothly change direction and reduce the cavitation noise generated at the moment of bypass opening.

[0014] Preferably, the sleeve is inserted into the rectifier channel, and the end face of the sleeve inserted into the rectifier channel is formed at an obtuse angle with the inner wall of the sleeve. The obtuse angle cone surface can not only decompose the fluid pressure of the positive impact into axial thrust and radial component force, optimizing the force distribution, but also guide the fluid to flow smoothly to the outside when the bypass is not opened, reducing dead angle eddy deposition at the end face.

[0015] Preferably, the outlet of the insulating carrier is provided with an anti-backflow hook, which extends inward at an acute angle to block the slight backflow caused by downstream fluid pressure fluctuations, ensuring the unidirectional stability of the flow field in the detection area; and forming a local flow separation zone at the outlet to prevent the outflowed abrasive particles from being re-entered into the insulating carrier due to turbulence, thus preventing detection errors.

[0016] Preferably, the inner wall surface of the insulating carrier is provided with a microtexture for disturbing the fluid near the wall surface. The microtexture is distributed circumferentially to disrupt the laminar flow layer at the pipe wall, prevent tiny abrasive particles from being adsorbed onto the pipe wall by viscous forces to form a deposit layer, thereby maintaining the long-term cleanliness of the inner wall of the channel and avoiding the reduction of the effective cross-section of the channel and signal baseline drift due to fouling.

[0017] Preferably, the insulating carrier includes a coil skeleton segment for winding the signal pickup coil, and the wall thickness of the coil skeleton segment is less than the wall thickness at both ends of the insulating carrier; the thinned wall shortens the distance between the abrasive grains and the coil, thereby improving the "fill factor" and signal amplitude of electromagnetic induction, and the concave structure plays a limiting and protective role for the signal pickup coil.

[0018] The detection method of the above-mentioned detection device includes the following steps: S1. Flow field pretreatment and particle acceleration: Lubricating oil in the gearbox is introduced into the detection sensitivity gain unit. The streamlined inner wall and straight section structure of the rectifier channel are used to rectify the flow field, eliminate the swirling component in the fluid and increase the flow velocity, so that the wear particles suspended in the lubricating oil can obtain the kinetic energy to move along the central axis of the channel. S2. Pressure Adaptive and Inertial Sorting: As fluid flows through the adaptive stabilizer area, the sleeve senses the fluid pressure. When the fluid pressure increases and pushes the sleeve to overcome the resistance of the elastic element and generate axial displacement, the peripheral flow bypass is opened for drainage. During this process, the momentum difference between wear particles and liquid oil is used to make the high-momentum wear particles maintain a ballistic linear motion due to inertia and enter the interior of the insulating carrier, while some liquid oil is turned and flows into the flow bypass under the pressure difference. S3. Weak Fault Feature Extraction: A sensitive magnetic field region is constructed using a signal pickup coil wound on an insulating carrier to capture electromagnetic disturbances caused by wear particles passing through the insulating carrier at high speed in real time, and converts the disturbances into electrical signals representing the wear state of the gearbox.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention resolves the conflict between bypass pressure relief and particle capture by utilizing the combination of a detection sensitivity gain unit and an adaptive stabilizer. The upstream rectifier channel guides wear particles in the oil to the central insulating carrier. When the oil pressure increases, pushing the sleeve to compress the elastic element and opening the peripheral flow bypass, heavier metal particles continue to enter the central detection area in a straight line due to inertia, while only liquid oil changes direction and enters the bypass. This ensures that even under cold start or high flow conditions, although the bypass is open for pressure relief, metal particles can still pass through the area where the signal pickup coil is located, preventing particles from being lost with the bypass oil.

[0020] 2. This invention improves the coil's ability to sense particles by optimizing the flow channel and coil mounting structure. The inner wall of the rectifier channel is designed as a streamlined straight cylindrical section with a constant cross-section. Combined with radially distributed pre-rectifier ribs at the inlet, this effectively smooths out turbulent fluid, allowing particles to pass through the detection zone parallel to the axis. Simultaneously, the wall thickness of the coil skeleton section wound on the insulating carrier is less than at both ends, thereby shortening the distance between the signal pickup coil and the particles in the internal fluid, resulting in a clearer induced signal generated by the coil.

[0021] 3. This invention utilizes a sliding guide fit between the sleeve and the insulating carrier in the adaptive stabilizer, and senses pressure changes to move axially under the action of the elastic element. The corresponding flow bypass employs an involute design with an opening area that gradually increases along the flow direction, ensuring a smooth flow transition when the bypass opens, avoiding sudden pressure drops or oscillations in the pipeline caused by the bypass opening instantaneously. Simultaneously, the anti-backflow hook located at the outlet of the insulating carrier uses its inward sharp angle to block fluid backflow, preventing already flowed abrasive particles from re-entering the detection area, thus ensuring unidirectional stability of the detection process. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall isometric structure of the present invention; Figure 2 This is a schematic diagram of the isometric structure with internal section of the present invention; Figure 3 This is a schematic diagram of the bypass closed state of the present invention; Figure 4 This is a schematic diagram of the bypass open state of the present invention; Figure 5 For the present invention Figure 3 Enlarged diagram of part A in the middle; Figure 6 For the present invention Figure 3 Enlarged diagram of section B; Figure 7 This is a schematic diagram of the overall left-side structure of the present invention; Figure 8 This is a schematic diagram of the entire invention from the right side.

[0023] In the diagram: 1. Fault feature extraction component; 11. Insulating carrier; 111. Anti-backflow hook; 112. Microstructure; 113. Coil frame segment; 12. Signal pickup coil; 2. Detection sensitivity gain unit; 21. Rectification channel; 211. Pre-rectification rib; 3. Flow bypass; 4. Adaptive stabilizer; 41. Sleeve; 42. Elastic element; 5. Housing. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Please see Figures 1 to 8 This invention provides a device and method for detecting the transmission stability of a multi-stage gearbox, the technical solution of which is as follows: A device for detecting the transmission stability of a multi-stage gearbox includes a fault feature extraction component 1, which is the core component of an intelligent sensor and is independent of the gearbox transmission link. The fault feature extraction component 1 includes an insulating carrier 11 defining a precision sampling channel and a signal pickup coil 12 wound on the insulating carrier 11. The signal pickup coil 12 is used to capture electromagnetic disturbances caused by particles passing through the insulating carrier 11 in real time. A detection sensitivity gain unit 2 is located upstream of the fault feature extraction component 1. The detection sensitivity gain unit 2 has a rectifier channel 21 that constrains dispersed abnormal wear products to the insulating carrier 11. An adaptive stabilizer 4 is arranged around the fault feature extraction component 1 and forms a flow bypass 3. The adaptive stabilizer 4 performs axial compensation displacement in response to fluid pressure fluctuations in the monitoring environment. The device also includes a housing 5 that provides mounting positions for the fault feature extraction component 1, the detection sensitivity gain unit 2, and the adaptive stabilizer 4.

[0026] In this embodiment, the rated operating flow rate of the detection device is designed to be 20–100 L / min. At this flow rate, the Reynolds number Re at the outlet of the rectifier channel 21 is > 2300. For density ρ p Ferromagnetic abrasive grains with a density of approximately 7.8 × 10³ kg / m³ are used to ensure a grain size d. p Particles ≥ 50 μm can overcome fluid drag and enter the insulating carrier 11. The design must satisfy the Stokes number Stk = τU0 / d_c ≫ 1, where τ is the particle relaxation time, U0 is the characteristic velocity, and the characteristic length d_c is chosen as the equivalent inner diameter at the outlet of the rectifying channel 21 in this device. The relaxation time τ can be estimated using the commonly used particle relaxation time expression in this field, which is mainly determined by the abrasive particle size, density, and oil viscosity. During the design process, the characteristic velocity U0 can be calculated based on the cross-sectional area of ​​the rectifying channel 21 outlet within the rated flow range, and the Stokes number Stk can be estimated accordingly. When the calculated Stk is significantly greater than 1, it ensures that ferromagnetic abrasive particles with a diameter of not less than 50 μm have sufficient inertial momentum when entering the insulating carrier 11 through the outlet of the rectifying channel 21, thereby overcoming fluid drag deflection and achieving the effect of entering the insulating carrier 11 along an approximately straight trajectory. This device is suitable for industrial gear oils with a kinematic viscosity range of 32 to 320 cSt.

[0027] As one embodiment of the present invention, refer to Figures 1 to 3The inner wall of the rectifying channel 21 is constructed as a streamlined curved surface with a continuously decreasing cross-sectional area along the fluid flow direction, and the outlet section of the rectifying channel 21 is constructed as a straight cylindrical structure with a constant cross-section. The streamlined curved surface can adopt a smooth contraction profile that satisfies the continuity of the inlet and outlet diameters and the first derivative. For example, in this embodiment, a high-order polynomial curve that meets the boundary conditions can be selected, so that the change in cross-sectional area of ​​the rectifying channel 21 in the length direction remains monotonous and smooth, so as to obtain a good acceleration effect and avoid boundary layer separation of the fluid during acceleration. The specific contraction ratio (ratio of inlet area to outlet area) of "continuously decreasing cross-sectional area" is preferably set between 4:1 and 8:1 to ensure that the fluid velocity increases by more than 2 times, thereby giving the suspended particles sufficient inertial momentum. The length of the straight cylindrical structure is preferably 3-5 times the pipe diameter. This length serves as a relaxation zone to eliminate the pulsation generated during fluid acceleration and ensure that the fluid enters the downstream insulating carrier 11 smoothly in a laminar flow state.

[0028] As one embodiment of the present invention, refer to Figure 3 and Figure 7 The inlet end of the rectifying channel 21 is provided with pre-rectifying ribs 211 arranged radially. The flow-facing surface of the pre-rectifying ribs 211 is constructed into a knife-edge wedge structure. In terms of manufacturing process, the rectifying channel 21 (including the pre-rectifying ribs 211) is preferably integrally injection molded or precision cast from high-strength engineering plastics (such as PEEK) or non-magnetic metals (such as austenitic stainless steel) to ensure structural strength. The rounding radius of the "knife-edge wedge structure" should be less than 0.2 mm to minimize impact disturbance to the fluid. In addition, the number of radially distributed pre-rectifying ribs 211 is preferably odd, so that it forms a non-perfectly asymmetrical disturbance distribution in the flow field, thereby weakening the resonance peak with downstream axisymmetric components (such as the insulating carrier 11 or the inner wall of the shell 5).

[0029] As one embodiment of the present invention, refer to Figure 3 and Figure 5 The adaptive stabilizer 4 includes a hollow sleeve 41 and an elastic element 42 that provides a restoring force to the sleeve 41. A sliding guide pair with a micro-gap fit is formed between the inner circumferential surface of the sleeve 41 and the outer surface of the insulating carrier 11. One end of the elastic element 42 abuts against the sleeve 41, and the other end abuts against the housing 5. A circumferential limiting structure is provided between the sleeve 41 and the insulating carrier 11 to prevent relative rotation. This limiting structure can be in the form of a longitudinal ridge on the inner wall of the sleeve 41 cooperating with a corresponding guide groove on the outer cylindrical surface of the insulating carrier 11, thereby ensuring that the sleeve 41 slides smoothly along the axial direction while restricting its circumferential rotation. Through the above structure, the circumferential torque generated by the fluid swirling component on the sleeve 41 can be offset, avoiding premature fatigue failure of the internal elastic element 42 due to repeated torsion, while not affecting the axial momentum transmission of the fluid itself.

[0030] Regarding the "micro-clearance fit," specifically, an H7 / g6 or H7 / f7 clearance fit is used between the inner bore of the sleeve 41 and the outer cylindrical surface of the insulating carrier 11, with the clearance value controlled within the range of 0.01mm to 0.03mm. This tiny gap allows some oil to seep in and form a "squeezed oil film," which not only provides lubrication but also utilizes the viscous damping effect of the oil to suppress chattering of the sleeve 41 under high-frequency pressure fluctuations. The sleeve 41 is preferably made of a material with a low coefficient of friction and high wear resistance, such as stainless steel with a Teflon coating or self-lubricating bronze, to prevent jamming caused by long-term sliding. The elastic element 42 is preferably a wave spring or a helical spring with customized stiffness, and its preload setting should correspond to the upper limit of the normal operating pressure of the gearbox, ensuring that the bypass is closed under normal operating conditions and only opens significantly during cold starts or pressure surges.

[0031] In this embodiment, the threshold pressure for bypass opening is set to P_set = 0.3 ~ 0.5 MPa. The preload force F_pre of the elastic element 42 is calculated as F_pre = P_set × S_eff, where S_eff is the effective pressure area of ​​the sleeve 41 end face. The selected helical spring stiffness k is approximately 10 ~ 15 N / mm, and the maximum compression stroke is designed to be 5 ~ 8 mm to ensure that the bypass flow area is greater than 1.5 times the cross-sectional area of ​​the upstream pipeline in the fully open state. The numerical ranges of P_set, k, and the maximum compression stroke are based on conventional small and medium-sized industrial gearbox lubrication systems as reference conditions, and are selected through empirical data under the premise that the normal lubrication pressure of the gearbox is not affected. For gearbox systems of different specifications or different working pressure levels, those skilled in the art can adjust the preload force and stiffness of the elastic element 42 appropriately according to the principle that "the bypass opening threshold is slightly higher than the upper limit of the normal working pressure of the system, and the bypass flow capacity in the fully open state is not less than 1.5 times the cross-sectional area of ​​the upstream pipeline".

[0032] As one embodiment of the present invention, refer to Figure 3 and Figure 4 The flow bypass 3 is configured as an involute structure, and the opening area of ​​the flow bypass 3 gradually increases along the oil flow direction; the outer wall of the sleeve 41 is configured as a conical structure, and the large-diameter end of the outer wall of the sleeve 41 is located on the oil outlet side. The inner wall of the housing 5 that cooperates with it to form the flow bypass 3 is a regular circumferential surface, so that the bypass flow coefficient and the axial displacement of the sleeve 41 are linear or quasi-linear, avoiding the system pressure shock caused by the sudden change in flow at the moment of opening of ordinary switching valves; in addition, the cone angle of the outer wall conical surface of the sleeve 41 is preferably designed to be between 15° and 30°. This angle range can ensure sufficient flow guiding capacity and further stabilize the centering of the sleeve 41 through the radial component force generated by the fluid.

[0033] As one embodiment of the present invention, refer to Figure 3 The sleeve 41 is inserted into the rectifier channel 21, and the end face of the sleeve 41 inserted into the rectifier channel 21 is at an obtuse angle to the inner wall of the sleeve 41. The obtuse angle surface, which is inclined inward, forms a converging guide port. In the bypass closed state, it actively and efficiently gathers the upstream flow and guides it into the sleeve 41, reducing the impact loss of the fluid at the inlet. Moreover, the obtuse angle surface serves as the fluid back pressure bearing surface. When the fluid flow rate increases or the viscosity increases, causing the back pressure to rise, the axial component of the fluid acting on the obtuse angle surface can quickly overcome the preload of the elastic element 42 and push the sleeve 41 to displace in order to open the bypass.

[0034] As one embodiment of the present invention, refer to Figure 3 , Figure 6 and Figure 8 An anti-backflow hook 111 is provided at the outlet of the insulating carrier 11. The anti-backflow hook 111 extends inward at an acute angle. The anti-backflow hook 111 is integrally formed at the outlet of the insulating carrier 11. Geometrically, it is a ring of barbed protrusions that converge radially from the inner wall of the channel towards the central axis and simultaneously tilt slightly upstream of the channel. This forms an annular backflow groove with an acute-angle cross-section at the junction of the outlet end face and the inner wall of the insulating carrier 11. When high-frequency pressure pulsation or local back pressure occurs downstream of the device due to the large opening of the adaptive stabilizer 4, the acute-angle hook structure can intercept the oil that climbs back up along the boundary layer of the pipe wall. At the same time, the sharp edge of the hook structure causes the fluid that has just flowed out of the insulating carrier 11 to quickly detach from the pipe wall, carrying metal abrasive particles. This eliminates the detection error caused by the abrasive particles repeatedly lingering in the edge area of ​​the signal pickup coil 12 due to the viscosity of the flow field at the outlet or the entrainment of the wake. This ensures the uniqueness of the single-pass signal and the stability of the detection baseline.

[0035] As one embodiment of the present invention, refer to Figure 5 The inner wall of the insulating carrier 11 is provided with a microtexture 112 for disturbing the fluid near the wall. The microtexture 112 can be a fine groove or stripe structure distributed axially or circumferentially, and its aspect ratio is preferably controlled within the range of 0.1 to 0.3, so as to break the stable laminar flow near the channel wall without significantly increasing the flow resistance. Combined with a coating material with good oleophobic properties, a low surface energy interface state can be formed on the inner wall, so that when the lubricating oil flows through this area, local micro-vortices are generated between the microstructures, which continuously scour the fine abrasive particles attached near the wall, thereby reducing the tendency of abrasive particles to deposit and accumulate on the wall. For clarity, Figure 3 The image only shows a portion of the structure of the microtexture 112; in actual production, the axial length of the microtexture 112 can be further extended.

[0036] As one embodiment of the present invention, refer to Figure 5The insulating carrier 11 includes a coil skeleton segment 113 for winding the signal pickup coil 12. The wall thickness of the coil skeleton segment 113 is less than the wall thickness at both ends of the insulating carrier 11. The signal pickup coil 12 is surrounded by an electromagnetic shielding layer, which is isolated from the signal pickup coil 12 by the insulating layer. This isolates stray electromagnetic interference from the external environment, improves the signal-to-noise ratio of the sensor in high-noise industrial environments, and simultaneously constrains the divergence of the coil's own magnetic field, concentrating the magnetic induction energy inside the insulating carrier 11.

[0037] The wall thickness of the coil bobbin section 113 should be reduced to meet the limit of withstand voltage, for example, 0.5mm to 1.0mm, to maximize the filling coefficient of the magnetic field. The insulating carrier 11 should be made of a high-molecular composite material (such as glass fiber reinforced nylon) to ensure mechanical rigidity in the thin-walled state. The electromagnetic shielding layer is preferably a multi-layer shield made of a high-permeability material (such as permalloy), and the shielding layer should be reliably grounded. To eliminate the fretting noise of the coil under fluid impact, the signal pickup coil 12 should be vacuum-encapsulated with epoxy resin or silicone after winding to solidify it with the insulating carrier 11.

[0038] The signal pickup coil 12 uses enameled copper wire with a diameter of Φ0.1~0.2 mm, tightly wound with 800~1200 turns, and has a static inductance of approximately 10~50 mH. The detection circuit applies a sinusoidal excitation signal with a frequency of 10~100 kHz, and identifies passing metal particles by detecting changes in the complex impedance (ΔZ) or induced electromotive force of the detection coil.

[0039] Working principle: Through the cooperation of the internal flow channel structure and movable parts, the wear particles of the gearbox are captured and detected. The specific process is as follows: The lubricating oil in the gearbox first enters the detection sensitivity gain unit 2 at the front end of the device. When the oil passes through the radially distributed pre-rectifying ribs 211 at the inlet, the blade-shaped flow-facing surfaces of the ribs break up large air bubbles mixed in the fluid. Subsequently, the oil enters the rectifying channel 21, whose inner wall gradually narrows. As the cross-sectional area of ​​the channel continuously decreases along the flow direction, the flow velocity of the oil increases, thereby accelerating the wear particles suspended in the oil and giving the particles a velocity that moves along the central axis of the channel.

[0040] The accelerated fluid rushes towards the obtuse-angled end face of the sleeve 41 in the adaptive stabilizer 4, which directly bears the thrust of the fluid. When the system pressure increases (such as during cold start or high-flow conditions), the oil thrust overcomes the resistance of the elastic element 42, pushing the sleeve 41 to slide axially backward, thereby opening the peripheral flow bypass 3; at the moment the bypass opens, the flow direction separates. The liquid oil flows into the bypass for pressure relief through the opened gap; while the heavier metal wear particles, due to inertia, are difficult to change direction sharply with the oil, but maintain their original straight-line trajectory and directly enter the interior of the central insulating carrier 11.

[0041] When abrasive particles pass through the insulating carrier 11, the signal pickup coil 12, wound on the coil frame section 113, captures the magnetic field changes caused by the particles and converts them into electrical signals. As the particles flow out of the detection channel, the anti-backflow hook 111 at the outlet of the insulating carrier 11 quickly removes the outflowing fluid and particles from the pipe wall, preventing particles from lingering at the outlet or being drawn in by the wake. At the same time, the anti-backflow hook 111 blocks the oil flowing back along the pipe wall, preventing detected particles from re-entering the coil area and ensuring accurate detection signals.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for detecting the transmission stability of a multi-stage gearbox, characterized in that, include: A fault feature extraction component independent of the gearbox transmission link, the fault feature extraction component comprising an insulating carrier defining a precision sampling channel and a signal pickup coil wound on the insulating carrier, the signal pickup coil being used to capture electromagnetic disturbances caused by particles passing through the insulating carrier in real time; The detection sensitivity gain unit located upstream of the fault feature extraction component is provided with a rectifier channel that constrains the dispersed abnormal wear products to the insulating carrier. An adaptive stabilizer is arranged around the fault feature extraction component and forms a flow bypass, the adaptive stabilizer performing axial compensation displacement in response to fluid pressure fluctuations in the monitored environment. The inner wall of the rectifier channel is constructed as a streamlined curved surface with a continuously decreasing cross-sectional area along the fluid flow direction, and the outlet section of the rectifier channel is constructed as a straight cylindrical structure with a constant cross-section. The adaptive stabilizer includes a hollow sleeve and an elastic element that provides a restoring force to the sleeve. A sliding guide pair with a micro-gap fit is formed between the inner circumferential surface of the sleeve and the outer surface of the insulating carrier. The flow bypass is configured as an involute structure, and the opening area of ​​the flow bypass gradually increases along the oil flow direction. The sleeve is inserted into the rectifier channel, and the end face of the sleeve inserted into the rectifier channel is formed at an obtuse angle with the inner wall of the sleeve.

2. The detection device according to claim 1, characterized in that: The inlet end of the rectifier channel is provided with pre-rectifier ribs distributed radially, and the frontal surface of the pre-rectifier ribs is constructed into a knife-edge wedge structure.

3. The detection device according to claim 1, characterized in that: The outlet of the insulating carrier is provided with an anti-backflow hook, which extends inward at an acute angle.

4. The detection device according to claim 1, characterized in that: The inner wall surface of the insulating carrier is provided with a microtexture for disturbing the fluid near the wall surface, and the microtexture is distributed circumferentially.

5. The detection device according to claim 1, characterized in that: The insulating carrier includes a coil skeleton segment for winding a signal pickup coil, the wall thickness of which is less than the wall thickness at both ends of the insulating carrier.

6. A detection method adapted to the detection device according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Flow field pretreatment and particle acceleration: Lubricating oil in the gearbox is introduced into the detection sensitivity gain unit. The streamlined inner wall and straight section structure of the rectifier channel are used to rectify the flow field, eliminate the swirling component in the fluid and increase the flow velocity, so that the wear particles suspended in the lubricating oil can obtain the kinetic energy to move along the central axis of the channel. S2. Pressure Adaptive and Inertial Sorting: As fluid flows through the adaptive stabilizer area, the sleeve senses the fluid pressure. When the fluid pressure increases and pushes the sleeve to overcome the resistance of the elastic element and generate axial displacement, the peripheral flow bypass is opened for drainage. During this process, the momentum difference between wear particles and liquid oil is used to make the high-momentum wear particles maintain a ballistic linear motion due to inertia and enter the interior of the insulating carrier, while some liquid oil is turned and flows into the flow bypass under the pressure difference. S3. Weak Fault Feature Extraction: A sensitive magnetic field region is constructed using a signal pickup coil wound on an insulating carrier to capture electromagnetic disturbances caused by wear particles passing through the insulating carrier at high speed in real time, and converts the disturbances into electrical signals representing the wear state of the gearbox.

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