Method and system for evaluating wear of water-lubricated thrust bearing pad based on pressure field weighting

Abstract

The invention relates to a pressure field weighted water-lubricated thrust bearing pad wear evaluation method and system, and belongs to the technical field of water-lubricated thrust bearing state monitoring, and the method comprises the steps: obtaining a theoretical water film pressure distribution field of a water-lubricated thrust bearing pad under a rated working condition; defining M * N wear thickness measuring points which are distributed in a regular grid shape on the wear surface of the tile; mapping the coordinate of each wear thickness measuring point to a theoretical water film pressure distribution field to obtain a theoretical water film pressure value corresponding to each wear thickness measuring point; calculating a weight coefficient corresponding to each wear thickness measuring point according to the theoretical water film pressure value; according to the weight coefficient and the wear thickness value of each wear thickness measuring point, calculating the weighted average wear thickness of the tile; and the weighted average wear thickness is compared with a preset threshold value, and whether the water-lubricated thrust bearing tile needs to be replaced or not is judged.

Description

Technical Field

[0001] This application relates to the field of water-lubricated thrust bearing condition monitoring technology, and more specifically, to a pressure field-weighted method and system for evaluating the wear of water-lubricated thrust bearing pads. Background Technology

[0002] Water-lubricated thrust bearings are widely used in marine equipment such as ships and vessels due to their environmental friendliness, high cooling efficiency, and compact structure. However, because water has a low viscosity (approximately 1 / 20 to 1 / 100 that of oil), it is difficult to form a complete lubricating film. Especially during startup, shutdown, or operation under harsh conditions such as wave impact, water-lubricated bearings exhibit poor load-bearing capacity and stability, leading to uneven wear on the bearing pad surface. Excessive wear of the bearing pad can cause increased bearing clearance, intensified vibration, and even bearing failure.

[0003] Currently, the assessment of thrust bearing pad wear mainly relies on periodic shutdowns and disassembly inspections, judging by measuring pad thickness or observing surface wear marks. Chinese Patent Publication No. CN109813232A discloses a method for detecting sliding bearing wear based on fiber optic grating length, obtaining wear amount by periodically measuring changes in grating length; however, this method cannot distinguish between uneven wear distribution. Chinese Patent Publication No. CN114518084A proposes a method for simultaneously monitoring lubricating film thickness and bearing pad wear using ultrasonic technology. This method uses ultrasonic echo signals from the air interface of the substrate-unworn pad structure as a reference signal and oil film reflection signals from the substrate-worn pad-lubricating oil-steel structure as the test signal. The amplitude and phase spectra of the signals are obtained through FFT transformation, ultimately establishing a calculation method to simultaneously obtain the sliding bearing oil film thickness and pad wear degree. However, this method cannot directly reflect the influence mechanism of pressure distribution on wear, and uneven pressure distribution is a key factor leading to uneven wear. Ultrasonic methods struggle to capture these pressure-related wear characteristic differences. Therefore, developing a wear assessment method that can reflect pressure distribution characteristics is of great significance for improving assessment accuracy and extending bearing life. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a pressure-field weighted method and system for evaluating the wear of water-lubricated thrust bearing pads.

[0005] The technical solution of this invention is as follows: This invention proposes a pressure-field-weighted method for evaluating the wear of water-lubricated thrust bearing pads, comprising the following steps: Obtain the theoretical water film pressure distribution field of the water-lubricated thrust bearing pad under rated operating conditions; Define M×N regularly grid-like wear thickness measurement points on the worn surface of the tile; The coordinates of each wear thickness measurement point are mapped to the theoretical water film pressure distribution field to obtain the theoretical water film pressure value corresponding to each wear thickness measurement point. Based on the theoretical water film pressure value, calculate the weighting coefficient corresponding to each wear thickness measurement point; The weighted average wear thickness of the bearing pad is calculated based on the weighting coefficient and wear thickness value of each wear thickness measurement point. The weighted average wear thickness is then compared with a preset threshold to determine whether the water-lubricated thrust bearing pad needs to be replaced.

[0006] Preferably, the theoretical water film pressure distribution field is obtained by solving the Reynolds equation based on the shaft speed, axial load, dynamic viscosity of the lubricating medium, actual geometric dimensions of the bearing pad and its supporting structure characteristics of the water-lubricated thrust bearing, to obtain the theoretical water film pressure distribution field covering the entire working surface of the bearing pad.

[0007] Preferably, the coordinates of each wear thickness measurement point are mapped to the theoretical water film pressure distribution field, and the pressure value at the corresponding position in the theoretical water film pressure distribution field is calculated based on the coordinates of the wear thickness measurement points using a bilinear interpolation algorithm.

[0008] Preferably, the formula for calculating the weighting coefficient is: ; In the formula: Here is the weight coefficient at coordinate (i,j); Let be the theoretical pressure value at coordinate (i,j).

[0009] Preferably, the formula for calculating the weighted average wear thickness is: ; In the formula: This represents the weighted average wear thickness of the tile. The actual wear thickness at coordinate (i,j) is given.

[0010] Preferably, the wear safety threshold is determined based on the allowable wear amount and safety factor of the tile material.

[0011] Preferably, the method further includes: calculating the remaining service life of the water-lubricated thrust bearing pad based on the weighted average wear thickness and its rate of change over time.

[0012] On the other hand, the present invention also provides a pressure field-weighted water-lubricated thrust bearing pad wear assessment system, comprising: The pressure field acquisition module acquires the theoretical water film pressure distribution field of the water-lubricated thrust bearing pad under rated operating conditions. The measurement point division module defines M×N regularly grid-distributed wear thickness measurement points on the wear surface of the tile; The pressure mapping module maps the coordinates of each wear thickness measurement point to the theoretical water film pressure distribution field, and obtains the theoretical water film pressure value corresponding to each wear thickness measurement point. The weight calculation module calculates the weight coefficient corresponding to each wear thickness measurement point based on the theoretical water film pressure value. The safety assessment module calculates the weighted average wear thickness of the bearing pads based on the weighting coefficients and wear thickness values ​​of each wear thickness measurement point; it then compares the weighted average wear thickness with a preset threshold to determine whether the water-lubricated thrust bearing pads need to be replaced.

[0013] In another aspect, the present invention also provides an electronic device having a computer program stored thereon, which, when executed by a processor, implements the pressure field-weighted water-lubricated thrust bearing pad wear assessment method as described in any embodiment of the present invention.

[0014] In another aspect, the present invention also provides a computer-readable medium for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the pressure field-weighted water-lubricated thrust bearing pad wear assessment method as described in any embodiment of the present invention.

[0015] The present invention has the following beneficial effects: 1. This invention introduces a theoretical water film pressure distribution field as a weighting matrix to perform a weighted average calculation on the wear data at the measurement points, giving wear data from high-load-bearing areas a higher weight in the overall evaluation. This mechanism ensures that the evaluation results are directly related to the actual stress state and performance degradation of the tiles, fundamentally overcoming the shortcomings of traditional methods with large evaluation deviations, and achieving a leap from "rough estimation" to "precise quantification" of wear status.

[0016] 2. The calculated weighted average wear thickness is an "equivalent uniform wear thickness" with a clear physical meaning. Compared with the simple arithmetic mean, this index can more scientifically characterize the overall wear state of the tile, providing a reliable and intuitive quantitative basis for judging the remaining service life and formulating maintenance strategies, greatly improving the scientificity and guidance of condition assessment.

[0017] 3. This invention uses pressure field weighted calculation to identify wear trends in critical areas earlier and more accurately, thus issuing early warnings before wear develops to a dangerous level. This can effectively avoid unplanned downtime or even major accidents caused by sudden failure of bearings, and significantly improve the safety and reliability of equipment operation. Attached Figure Description

[0018] Figure 1This is a flowchart of the method of the present invention; Figure 2 This is a cloud map showing the pressure distribution of the water film. Figure 3 Structural diagram of a water-lubricated thrust bearing test bench; Figure 4 This is a structural diagram of a tile wear thickness measuring device; Figure 5 This is a distribution map of the measurement points for the wear thickness of the tile. Figure 6 This is a distribution map of the water film pressure measurement points on the tile blocks. Detailed Implementation

[0019] 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.

[0020] It should be understood that the step numbers used in the text are for ease of description only and are not intended to limit the order in which the steps are performed.

[0021] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0022] The terms “comprising” and “including” indicate the presence of the described feature, whole, step, operation, element and / or component, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0023] The term “and / or” refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes these combinations.

[0024] Example 1: To make the objectives, technical solutions, and advantages of this invention clearer, specific embodiments of this application will be described below, with reference to the accompanying drawings. Figure 1 The technical solution of the present invention will be clearly and completely described.

[0025] To address the problems in the existing technology, this embodiment provides a pressure-field weighted method for evaluating the wear of water-lubricated thrust bearing pads, including the following steps: Obtain the theoretical water film pressure distribution field of the water-lubricated thrust bearing pad under rated operating conditions; In a preferred embodiment of this invention, the theoretical water film pressure distribution field is obtained by solving the Reynolds equation based on the shaft speed, axial load, dynamic viscosity of the lubricating medium, actual geometric dimensions of the bearing pad, and characteristics of its supporting structure. The specific formula for solving the Reynolds equation is as follows: ; In the formula: P(x,y) is the water film pressure, which is the variable to be solved; h is the water film thickness; The viscosity of the lubricating water; is the shaft rotation speed; x, y are the tile surface coordinates; In this embodiment, the water film pressure distribution field of the bearing blocks under rated operating speed (1000 rpm, load 0.3 MPa) is calculated numerically to obtain the following results: Figure 2 The pressure cloud diagram shown shows the highest pressure. =1.445 MPa, located at the center of the tile, slightly off the exit side.

[0026] Define M×N regularly grid-like wear thickness measurement points on the worn surface of the tile; This embodiment uses a water-lubricated thrust bearing test bench to conduct a wear assessment experiment. The composition and main parameters of the test bench are as follows: Motor: A three-phase asynchronous motor with a rated power of 5.5kw and a maximum speed of 1500 rpm is selected, and a high-precision speed control system is provided.

[0027] Torque sensor: It can collect signals such as speed and torque, with a range of 0-100 N·m.

[0028] Test water tank and internal structure: The water tank adopts a closed structure; the friction pair adopts a thrust bearing structure, the pad material is Sailong material, and the pad contact surface size is 0.03 m * 0.04 m; the thrust disc material is aluminum bronze. Spring loading system: maximum loading capacity 3 kN, spring controlled, loading accuracy ±0.5%.

[0029] A self-built tile wear thickness measuring device (measurement accuracy ±1μm) was used, specifically as follows: Figure 4 As shown; including: Digital dial indicator: The core measuring unit. Its measuring probe directly contacts the surface of the tile being measured, converting minute vertical displacements into high-precision digital readings, enabling direct measurement of wear thickness. Its digital display function facilitates quick and accurate data reading.

[0030] Alloy clamp holder: Support and positioning unit. Used to securely clamp the dial indicator's stem and provide stable and reliable support. Its design allows for flexible adjustment of the dial indicator's height, angle, and horizontal position, ensuring that the measuring contacts are accurately aligned with the designated measuring points on the tile surface.

[0031] Marble platform: Reference plane unit. It provides an extremely stable, flat, and non-deformable reference platform for the entire measurement system. Its high rigidity and low coefficient of thermal expansion ensure the absolute flatness of the reference surface during measurement, forming the basis for ensuring that all measurement point data have a unified reference datum.

[0032] The steps for measuring wear thickness are as follows: Wear tests were conducted using a water-lubricated thrust bearing test bench. The rated operating conditions were set as follows: speed 1000 rpm, load 0.3 MPa, water temperature 23℃. The bearing was run continuously for 5 hours to simulate actual operating conditions and induce measurable wear on the bearing pads.

[0033] After the experiment, the machine was stopped and the thrust bearing pads were disassembled. The surface of the pads was thoroughly cleaned with a special cleaning agent to ensure that the measurement reference surface was clean and free of contamination. The pads were then dried in a drying oven for 8 hours to eliminate measurement errors caused by water absorption and expansion.

[0034] After drying, define 6×8 wear thickness measurement points on the worn surface of the tile, such as... Figure 5 As shown, the measurement points are arranged in a regular grid to ensure coverage of the entire actual wear contact area. The wear depth value at each grid measurement point is measured using a tile wear thickness measuring device. Each point is measured three times, and the average value is taken. The results are shown in Table 1.

[0035] Table 1. Measurement values ​​of wear thickness at the measuring points of the tile (unit: mm)

[0036] The coordinates of each wear thickness measurement point are mapped to the theoretical water film pressure distribution field to obtain the theoretical water film pressure value corresponding to each wear thickness measurement point. In this embodiment, the coordinates of each measurement point are... Mapping this data to the calculated theoretical pressure distribution field P(x,y), we obtain the theoretical water film pressure value corresponding to each measurement point. ,like Figure 6 As shown in the figure, the results are shown in Table 2.

[0037] Table 2 Pressure values ​​at water film pressure measurement points on tile blocks (Unit: MPa)

[0038] In a preferred embodiment of this invention, the coordinates of each wear thickness measurement point are mapped to the theoretical water film pressure distribution field, and the pressure value at the corresponding position in the theoretical water film pressure distribution field is calculated based on the coordinates of the wear thickness measurement point using a bilinear interpolation algorithm.

[0039] Based on the theoretical water film pressure value, calculate the weighting coefficient corresponding to each wear thickness measurement point; In this embodiment, the theoretical pressure values ​​for each measurement point are obtained from Table 2. Determine the weighting coefficient for each measurement point. The results are shown in Table 3.

[0040] Table 3 Weighting coefficients for tile measurement points

[0041]

[0042] In a preferred embodiment of this invention, the formula for calculating the weighting coefficient is as follows: ; In the formula: Here is the weight coefficient at coordinate (i,j); Let be the theoretical pressure value at coordinate (i,j).

[0043] The weighted average wear thickness of the bearing pad is calculated based on the weighting coefficient and wear thickness value of each wear thickness measurement point. The weighted average wear thickness is then compared with a preset threshold to determine whether the water-lubricated thrust bearing pad needs to be replaced.

[0044] In a preferred embodiment of this invention, the formula for calculating the weighted average wear thickness is as follows: ; In the formula: This represents the weighted average wear thickness of the tile. The actual wear thickness at coordinate (i,j) is given.

[0045] Based on the calculated weighted average wear thickness of the tiles Compare it with the preset material safety wear threshold. A comparison was made. The tile material is Sailon, and its allowable abrasion allowance is typically taken as... Selecting a safety factor based on engineering experience The safety threshold is: ; because: ; The bearing is still in safe service condition and has not reached the failure criteria. Therefore, it does not need to be replaced immediately and can continue to operate; it can be re-inspected at the next maintenance cycle to monitor its wear trend.

[0046] In a preferred embodiment of this invention, the wear safety threshold is determined based on the allowable wear amount and safety factor of the tile material.

[0047] In a preferred embodiment of this invention, the method further includes: calculating the remaining service life of the water-lubricated thrust bearing pad based on the weighted average wear thickness and its rate of change over time.

[0048] Example 2: This embodiment provides a pressure field-weighted water-lubricated thrust bearing pad wear assessment system, including: The pressure field acquisition module acquires the theoretical water film pressure distribution field of the water-lubricated thrust bearing pad under rated operating conditions. The measurement point division module defines M×N regularly grid-distributed wear thickness measurement points on the wear surface of the tile; The pressure mapping module maps the coordinates of each wear thickness measurement point to the theoretical water film pressure distribution field, and obtains the theoretical water film pressure value corresponding to each wear thickness measurement point. The weight calculation module calculates the weight coefficient corresponding to each wear thickness measurement point based on the theoretical water film pressure value. The safety assessment module calculates the weighted average wear thickness of the bearing pads based on the weighting coefficients and wear thickness values ​​of each wear thickness measurement point; it then compares the weighted average wear thickness with a preset threshold to determine whether the water-lubricated thrust bearing pads need to be replaced.

[0049] Example 3: This embodiment provides an electronic device that stores a computer program, which, when executed by a processor, implements a pressure field-weighted water-lubricated thrust bearing pad wear assessment method as described in any embodiment of the present invention.

[0050] Example 4: This embodiment provides a computer-readable medium for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the pressure field-weighted water-lubricated thrust bearing pad wear assessment method as described in any embodiment of the present invention.

[0051] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, A and B simultaneously, or B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0052] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0053] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0054] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part 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 all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0055] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method of pressure field weighted water-lubricated thrust bearing pad wear assessment, characterized by, The method comprises the following steps: obtaining a theoretical water film pressure distribution field of a water-lubricated thrust bearing pad under a rated working condition; defining M×N regularly grid-distributed wear thickness measurement points on the wear surface of the pad; mapping the coordinates of each wear thickness measurement point to the theoretical water film pressure distribution field to obtain a theoretical water film pressure value corresponding to each wear thickness measurement point; calculating a weight coefficient corresponding to each wear thickness measurement point according to the theoretical water film pressure value; calculating a weighted average wear thickness of the pad according to the weight coefficient and the wear thickness value of each wear thickness measurement point; and comparing the weighted average wear thickness with a preset threshold to determine whether the water-lubricated thrust bearing pad needs to be replaced.

2. The pressure field weighted water-lubricated thrust bearing pad wear assessment method of claim 1, wherein: The theoretical water film pressure distribution field is based on the shaft rotating speed, the axial load, the dynamic viscosity of the lubricating medium, the actual geometric size of the pad and the support structure characteristics of the water-lubricated thrust bearing, and is obtained by solving the Reynolds equation to cover the entire working surface of the pad.

3. The pressure field weighted water-lubricated thrust bearing pad wear assessment method of claim 1, wherein: The coordinates of each wear thickness measurement point are mapped to the theoretical water film pressure distribution field by a bilinear interpolation algorithm to calculate the pressure value of the corresponding position in the theoretical water film pressure distribution field according to the coordinates of the wear thickness measurement point.

4. The pressure field weighted water-lubricated thrust bearing pad wear assessment method of claim 1, wherein: The weight coefficient calculation formula is: ； where: is the weight coefficient at coordinate (i,j); is the theoretical pressure value at coordinate (i,j).

5. The pressure field weighted water-lubricated thrust bearing pad wear assessment method of claim 4, wherein: The weighted average wear thickness calculation formula is: ； where: is the weighted average wear thickness of the tile; is the actual wear thickness at coordinate (i,j).

6. The pressure field weighted water-lubricated thrust bearing pad wear assessment method of claim 1, wherein: The wear safety threshold is determined according to the allowable wear amount and the safety coefficient of the pad material.

7. The pressure field weighted water-lubricated thrust bearing pad wear assessment method of claim 1, wherein: The method further comprises calculating the remaining service life of the water-lubricated thrust bearing pad according to the weighted average wear thickness and the rate of change thereof over time.

8. A pressure field weighted water-lubricated thrust bearing pad wear assessment system, characterized by, The method comprises: a pressure field acquisition module that acquires a theoretical water film pressure distribution field of a water-lubricated thrust bearing pad under a rated working condition; a measurement point division module that defines M×N regularly grid-distributed wear thickness measurement points on the wear surface of the pad; a pressure mapping module that maps the coordinates of each wear thickness measurement point to the theoretical water film pressure distribution field to obtain a theoretical water film pressure value corresponding to each wear thickness measurement point; a weight calculation module that calculates a weight coefficient corresponding to each wear thickness measurement point according to the theoretical water film pressure value; a safety evaluation module that calculates a weighted average wear thickness of the pad according to the weight coefficient and the wear thickness value of each wear thickness measurement point; and compares the weighted average wear thickness with a preset threshold to determine whether the water-lubricated thrust bearing pad needs to be replaced.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor implements the pressure field weighted water-lubricated thrust bearing pad wear evaluation method as claimed in claims 1-7 when executing the program.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program implements the pressure field weighted water-lubricated thrust bearing pad wear evaluation method as claimed in claims 1-7 when executed by the processor.

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