A test method and system for assessing the wear reliability of large water-lubricated bearings

Abstract

This invention relates to the field of testing technology for large ship propulsion systems, specifically to a test method and system for assessing the wear reliability of large water-lubricated bearings. This invention ensures the similarity in lubrication and cooling performance among three pairs of friction pairs tested—material test blocks, scaled-down samples, and full-scale prototypes—in terms of test objects. When comparing and analyzing wear, the influence of relative sliding speed on wear is simplified by using a linear velocity cyclic test design with the same time span, thus simplifying the wear rate model of the water-lubricated bearing. Compared to solely relying on the durability cyclic test data of the full-scale prototype, the addition of scaled-down sample tests reduces the randomness of test data, and the use of the maximum average wear value as input to determine the wear model of the water-lubricated bearing improves the engineering reliability of the assessment method. This invention can shorten the testing and assessment cycle for the wear reliability of large water-lubricated bearings, save testing costs, and provide highly accurate assessment results.

Description

Technical Field

[0001] This invention relates to the field of testing technology for large ship propulsion systems, specifically to a test method and system for assessing the wear reliability of large water-lubricated bearings. Background Technology

[0002] During the navigation of large ships, the main failure mode of water-lubricated bearings is wear failure. Wear failure of water-lubricated bearings is a long-term cumulative process, mainly manifested by direct or indirect contact between the bearing liner and abrasive particles in the shaft system or lubricating fluid, resulting in the loss of the bearing liner material. Like other mechanical materials, the liner material of water-lubricated bearings in large ships follows a "bathtub curve" of failure rate. The wear process of water-lubricated bearings can be divided into three stages: the break-in stage, the stable wear stage, and the severe wear stage.

[0003] Existing test schemes for the wear reliability of water-lubricated bearings in large ships have long analysis and evaluation cycles and high test costs. With the continuous development of propulsion systems for large ships, they are increasingly unable to meet the needs of the industry. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a test method and system for evaluating the wear reliability of large water-lubricated bearings, which can shorten the test and evaluation cycle of the wear reliability of large water-lubricated bearings, save test costs, and provide high accuracy of evaluation results, in order to address the shortcomings of the existing technology.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] I. A Test Method for Wear Reliability Assessment of Large Water-Lubricated Bearings

[0007] This invention provides a test method for evaluating the wear reliability of large water-lubricated bearings, comprising the following steps:

[0008] S1, Design the test object, which includes a full-scale prototype of the water-lubricated bearing to be tested, a scaled-down sample, and a material test block;

[0009] S2, Establish a wear rate model for water-lubricated bearings under the stable wear stage;

[0010] S3, by limiting the test conditions, the wear rate model of the water-lubricated bearing is optimized to obtain a simplified wear rate model of the water-lubricated bearing;

[0011] S4, conduct multiple wear tests on the full-scale prototype, scaled-down prototype and material test block respectively;

[0012] S5. Based on the simplified model of the wear rate of the water-lubricated bearing and the wear data from the multiple wear tests, solve the wear reliability life model of the water-lubricated bearing.

[0013] Preferably, in step S1, the shape and size of the scaled-down sample are obtained by proportionally reducing the scaled-down version of the water-lubricated bearing prototype to be tested, and the material test block is obtained by uniformly dividing the scaled-down version of the water-lubricated bearing prototype to be tested into multiple segments along the circumferential direction.

[0014] Preferably, in step S1, the test shafts of the full-scale prototype, the scaled-down sample, and the material test block are made of the same material and have the same shaft diameter, and the inner lining grooves of the full-scale prototype, the scaled-down sample, and the material test block are distributed at the same angle along the circumferential direction.

[0015] Preferably, in step S2, the wear rate model of the water-lubricated bearing under the stable wear stage is as follows:

[0016]

[0017] In the formula:

[0018] —Wear amount / wear time;

[0019] k—wear coefficient, which is related to the bearing structure dimensions;

[0020] P—Radial load on the bearing friction surface;

[0021] v — relative sliding speed;

[0022] a, b — constants.

[0023] Preferably, in step S3, the limiting test conditions specifically include: the cooling water environment, relative sliding speed, test cycle, and test time allocation ratio at each test speed within the test cycle are kept consistent when the full-scale prototype, scaled-down prototype, and material test block undergo multiple wear tests.

[0024] Preferably, in step S3, the simplified model for the wear rate of the water-lubricated bearing is as follows:

[0025]

[0026] k0 — Simplified wear coefficient.

[0027] Preferably, in step S4, both the full-scale prototype and the scaled-down prototype undergo n wear tests, and the wear data of the full-scale prototype is recorded as M1 to M... n The wear data of the scaled-down sample are denoted as m1 to m2. n ;

[0028] The material specimen was subjected to n-1 wear tests, with the load conditions applied in each test being P1 to P2. n-1Wear data are recorded as h1 to h2. n-1 , where n≥5.

[0029] Preferably, in step S5, solving the wear reliability life model of the water-lubricated bearing specifically includes the following steps:

[0030] S11, the material test block is subjected to different load conditions P1 to P2. n-1 The wear data h1~h below n-1 Substitute them into the simplified model of material specimen wear rate respectively. In the process, the parameter k is obtained by fitting and solving. 01 and a;

[0031] S12, calculate the average wear amount of the full-scale prototype and the scaled-down prototype in n wear tests respectively. and

[0032] S13, take the maximum average wear value According to the formula Solving for the parameter k 02 ;

[0033] S14, according to parameter k 02 Establish a wear reliability life model for water-lubricated bearings.

[0034] S15. Based on the actual load P0 and allowable wear amount h0 of the water-lubricated bearing to be tested, the wear life T0 of the water-lubricated bearing to be tested is calculated.

[0035] II. A test system for assessing the wear reliability of large water-lubricated bearings

[0036] Based on the same inventive concept, this invention also provides a large water-lubricated bearing wear reliability assessment test system, used to implement the large water-lubricated bearing wear reliability assessment test method as described above, mainly including:

[0037] 1) Real-scale prototype testing module, used to conduct functional performance tests and wear and durability tests on real-scale prototypes;

[0038] 2) Scaled-down sample testing module, used to conduct functional performance tests and wear durability tests on scaled-down samples;

[0039] 3) Material test block testing module, used to conduct wear model tests, accelerated wear tests and wear durability comparison tests on material test blocks.

[0040] Preferably, the full-scale prototype test module, the scaled-down prototype test module, and the material block test module all use the same test shaft material, test shaft diameter, cooling water environment, relative sliding speed, test cycle, and test time allocation ratio at each test speed within the test cycle.

[0041] Compared with the prior art, the present invention has the following main advantages:

[0042] 1. Compared with simply relying on the durability cycle test data of a full-scale prototype, this invention reduces the randomness of test data and saves test costs by adding scaled-down prototype tests and material block tests. Furthermore, by taking the maximum average wear value as the input to determine the wear model of the water-lubricated bearing, the reliability of the evaluation method in engineering is improved.

[0043] 2. This invention ensures the similarity of three pairs of friction pairs in terms of lubrication and cold energy performance, using material test blocks, scaled-down samples, and full-scale prototypes as test objects, while reducing the influence of lubricant factors on friction and wear in the friction pairs;

[0044] 3. When comparing and analyzing wear, this invention simplifies the influence of relative sliding speed on wear by using a linear velocity cyclic test design with the same time span, thereby simplifying the wear rate model of water-lubricated bearings and effectively reducing the test and evaluation cycle. Attached Figure Description

[0045] Figure 1 This is a cross-sectional schematic diagram of a real-scale prototype in an embodiment of the present invention;

[0046] Figure 2 This is a cross-sectional schematic diagram of a scaled-down sample in an embodiment of the present invention;

[0047] Figure 3 This is a cross-sectional schematic diagram of the material test block in an embodiment of the present invention;

[0048] Figure 4 This is a flowchart of the test method for evaluating the wear reliability of large water-lubricated bearings in an embodiment of the present invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0050] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0051] Example 1: This example provides a test method for evaluating the wear reliability of large water-lubricated bearings. Based on a water-lubricated bearing wear model, and combined with functional performance tests, scaled-down sample and material block test data of large water-lubricated bearings, the reliability analysis and evaluation of water-lubricated bearings for large ships are conducted.

[0052] Its main features are as follows:

[0053] 1) When designing the test objects, all test shafts are made of the same material. The shaft diameters of the shafts used for the material block test and the scaled-down sample test are the same. The material block, scaled-down sample and the inner lining groove of the full-scale prototype are distributed at the same angle along the circumferential direction.

[0054] 2) During reliability testing, the relative sliding speeds of the material test blocks, scaled-down samples, and full-scale prototypes are kept the same, the test cycle is fixed, and the test time allocation ratio under each rotational speed condition within the test cycle is constant.

[0055] 3) The cooling water environment is the same for material test blocks, scaled-down samples and full-scale prototypes during reliability testing.

[0056] 4) When conducting reliability assessment and determining the prototype wear model, two test objects are selected: a scaled-down sample and a full-scale prototype. The maximum value among the average values ​​of the wear amounts in six sets of durability test cycles is used as the assessment input.

[0057] After the break-in period, water-lubricated bearings of large ships enter the stable wear stage. In the stable wear stage, the wear amount of water-lubricated bearings follows an approximately linear relationship with the wear time.

[0058] The wear rate model for water-lubricated bearings is as follows:

[0059]

[0060] In the formula:

[0061] —Wear amount / wear time;

[0062] k—wear coefficient, which is related to the bearing structure type;

[0063] P—Radial load on the bearing friction surface;

[0064] v — relative sliding speed;

[0065] a, b — constants.

[0066] This invention optimizes the wear rate model of the water-lubricated bearing by limiting experimental conditions, resulting in a simplified wear rate model for the water-lubricated bearing:

[0067]

[0068] k0 — Simplified wear coefficient.

[0069] The present invention will now be described in further detail with reference to the accompanying drawings.

[0070] (1) Test subjects

[0071] The test objects in this experiment included material specimens, scaled-down samples, and full-scale prototypes. Their cross-sectional structures are shown in the attached figure. The three test objects have similar distribution of water tanks along the circumference and are manufactured using the same process.

[0072] (2) Test items, working conditions, and methods

[0073] by Figure 1 The tests conducted on the full-scale prototype shown included functional performance and durability tests. Figure 2 The tests conducted on the scaled-down sample shown included functional performance and durability tests. Figure 3 The tests conducted on the material specimens shown included wear model tests, accelerated wear tests, and durability comparison tests.

[0074] During the test, the cooling water environment conditions and relative sliding linear velocities of the three test objects were the same. The test time distribution ratio under each linear velocity condition within a single cycle was constant, and the total test time for each cycle was constant at T. The test loads for the scaled-down prototype and the full-scale prototype were the same.

[0075]

[0076] (3) Data processing and evaluation analysis

[0077] 1) Determine the wear model

[0078] Based on the wear data (h1, h2, h3, h4, h5) of the material specimen under five different specific pressure conditions (P1, P2, P3, P4, P5), a wear model of the material specimen was obtained through fitting. The parameter k in 01 and a.

[0079] 2) Solving the wear reliability life model of water-lubricated bearings

[0080] according to Determine the average wear of the full-scale prototype and the scaled-down prototype during durability cycles, and take... Based on the wear test results h n and h7, according to the formula Determine k 02 .

[0081] According to k 02 a) Determine the prototype bearing wear model

[0082] Based on the working specific pressure P0 and allowable wear h0 of the prototype, according to The wear life T0 of the prototype was calculated.

[0083] Example 2: This example provides a test method for evaluating the wear reliability of large water-lubricated bearings, such as... Figure 4 As shown, the specific steps include the following:

[0084] S1, Design the test object, which includes a full-scale prototype of the water-lubricated bearing to be tested, a scaled-down sample, and a material test block;

[0085] S2, Establish a wear rate model for water-lubricated bearings under the stable wear stage;

[0086] S3, by limiting the test conditions, the wear rate model of the water-lubricated bearing is optimized to obtain a simplified wear rate model of the water-lubricated bearing;

[0087] S4, conduct multiple wear tests on the full-scale prototype, scaled-down prototype and material test block respectively;

[0088] S5. Based on the simplified model of the wear rate of the water-lubricated bearing and the wear data from the multiple wear tests, solve the wear reliability life model of the water-lubricated bearing.

[0089] Furthermore, in step S1, the shape and size of the scaled-down sample are obtained by proportionally reducing the scaled-down version of the water-lubricated bearing prototype to be tested, and the material test block is obtained by uniformly dividing the scaled-down version of the water-lubricated bearing prototype to be tested into multiple segments along the circumferential direction.

[0090] Furthermore, in step S1, the test shafts of the full-scale prototype, the scaled-down sample, and the material test block are made of the same material and have the same shaft diameter, and the inner lining grooves of the full-scale prototype, the scaled-down sample, and the material test block are distributed at the same angle along the circumferential direction.

[0091] Furthermore, in step S2, the wear rate model of the water-lubricated bearing under the stable wear stage is as follows:

[0092]

[0093] In the formula:

[0094] —Wear amount / wear time;

[0095] k—wear coefficient, which is related to the bearing structure dimensions;

[0096] P—Radial load on the bearing friction surface;

[0097] v — relative sliding speed;

[0098] a, b — constants.

[0099] Furthermore, in step S3, the limiting test conditions specifically include: the cooling water environment, relative sliding speed, test cycle, and test time allocation ratio at each test speed within the test cycle remain consistent when the full-scale prototype, scaled-down prototype, and material test block undergo multiple wear tests.

[0100] Furthermore, in step S3, the simplified model for the wear rate of the water-lubricated bearing is as follows:

[0101]

[0102] k0 — Simplified wear coefficient.

[0103] Preferably, in step S4, both the full-scale prototype and the scaled-down prototype undergo n wear tests, and the wear data of the full-scale prototype is recorded as M1 to M... n The wear data of the scaled-down sample are denoted as m1 to m2. n ;

[0104] The material specimen was subjected to n-1 wear tests, with the load conditions applied in each test being P1 to P2. n-1 Wear data are recorded as h1 to h2. n-1 , where n≥5.

[0105] Furthermore, in step S5, solving the wear reliability life model of the water-lubricated bearing specifically includes the following steps:

[0106] S11, the material test block is subjected to different load conditions P1 to P2. n-1 The wear data h1~h below n-1 Substitute them into the simplified model of material specimen wear rate respectively. In the process, the parameter k is obtained by fitting and solving. 01 and a;

[0107] S12, calculate the average wear amount of the full-scale prototype and the scaled-down prototype in n wear tests respectively. and

[0108] S13, take the maximum average wear value According to the formula Solving for the parameter k 02 ;

[0109] S14, according to parameter k 02 Establish a wear reliability life model for water-lubricated bearings.

[0110] S15. Based on the actual load P0 and allowable wear amount h0 of the water-lubricated bearing to be tested, the wear life T0 of the water-lubricated bearing to be tested is calculated.

[0111] Example 3, based on the same inventive concept, also provides a large water-lubricated bearing wear reliability assessment test system, used to implement the large water-lubricated bearing wear reliability assessment test method as described above, mainly including:

[0112] 1) Real-scale prototype testing module, used to conduct functional performance tests and wear and durability tests on real-scale prototypes;

[0113] 2) Scaled-down sample testing module, used to conduct functional performance tests and wear durability tests on scaled-down samples;

[0114] 3) Material test block testing module, used to conduct wear model tests, accelerated wear tests and wear durability comparison tests on material test blocks.

[0115] Furthermore, the full-scale prototype test module, the scaled-down prototype test module, and the material block test module all use the same test shaft material, test shaft diameter, cooling water environment, relative sliding speed, test cycle, and test time allocation ratio at each test speed within the test cycle.

[0116] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0117] In summary:

[0118] 1. Compared with simply relying on the durability cycle test data of a full-scale prototype, this invention reduces the randomness of test data and saves test costs by adding scaled-down prototype tests and material block tests. Furthermore, by taking the maximum average wear value as the input to determine the wear model of the water-lubricated bearing, the reliability of the evaluation method in engineering is improved.

[0119] 2. This invention ensures the similarity of three pairs of friction pairs in terms of lubrication and cold energy performance, using material test blocks, scaled-down samples, and full-scale prototypes as test objects, while reducing the influence of lubricant factors on friction and wear in the friction pairs;

[0120] 3. When comparing and analyzing wear, this invention simplifies the influence of relative sliding speed on wear by using a linear velocity cyclic test design with the same time span, thereby simplifying the wear rate model of water-lubricated bearings and effectively reducing the test and evaluation cycle.

[0121] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A test method for evaluating the wear reliability of large water-lubricated bearings, characterized in that, Includes the following steps: S1, Design the test object, which includes a full-scale prototype of the water-lubricated bearing to be tested, a scaled-down sample, and a material test block; S2, Establish a wear rate model for water-lubricated bearings under the stable wear stage; S3, by limiting the test conditions, the wear rate model of the water-lubricated bearing is optimized to obtain a simplified wear rate model of the water-lubricated bearing; S4, conduct multiple wear tests on the full-scale prototype, scaled-down prototype and material test block respectively; S5. Based on the simplified model of the wear rate of the water-lubricated bearing and the wear data from the multiple wear tests, solve the wear reliability life model of the water-lubricated bearing.

2. The test method for evaluating the wear reliability of a large water-lubricated bearing according to claim 1, characterized in that... In step S1, the shape and size of the scaled-down sample are obtained by scaling down the full-scale prototype of the water-lubricated bearing to be tested, and the material test block is obtained by uniformly dividing the full-scale prototype of the water-lubricated bearing to be tested into multiple segments along the circumferential direction.

3. The test method for evaluating the wear reliability of a large water-lubricated bearing according to claim 2, characterized in that... In step S1, the test shafts of the full-scale prototype, the scaled-down sample, and the material test block are made of the same material and have the same shaft diameter, and the inner lining grooves of the full-scale prototype, the scaled-down sample, and the material test block are distributed at the same angle along the circumferential direction.

4. The test method for evaluating the wear reliability of a large water-lubricated bearing according to claim 1, characterized in that... In step S2, the wear rate model of the water-lubricated bearing under the stable wear stage is as follows: In the formula: —Wear amount / wear time; k—wear coefficient, which is related to the bearing structure dimensions; P—Radial load on the bearing friction surface; v — relative sliding speed; a, b — constants.

5. The test method for evaluating the wear reliability of a large water-lubricated bearing according to claim 4, characterized in that... In step S3, the limiting test conditions specifically include: the cooling water environment, relative sliding speed, test cycle, and test time allocation ratio at each test speed within the test cycle are kept consistent when the full-scale prototype, scaled-down prototype, and material test block undergo multiple wear tests.

6. The test method for evaluating the wear reliability of a large water-lubricated bearing according to claim 5, characterized in that... In step S3, the simplified model for the wear rate of the water-lubricated bearing is as follows: k0 — Simplified wear coefficient.

7. The test method for evaluating the wear reliability of a large water-lubricated bearing according to claim 6, characterized in that... In step S4, both the full-scale prototype and the scaled-down prototype undergo n wear tests, and the wear data of the full-scale prototype is recorded as M1 to M2. n The wear data of the scaled-down sample are denoted as m1 to m2. n ; The material specimen was subjected to n-1 wear tests, with the load conditions applied in each test being P1 to P2. n-1 Wear data are recorded as h1 to h2. n-1 , where n≥5.

8. The test method for evaluating the wear reliability of a large water-lubricated bearing according to claim 7, characterized in that... Step S5, which involves solving the wear reliability life model of the water-lubricated bearing, specifically includes the following steps: S11, the material test block is subjected to different load conditions P1 to P2. n-1 The wear data h1~h below n-1 Substitute them into the simplified model of material specimen wear rate respectively. In the process, the parameter k is obtained by fitting and solving. 01 and a; S12, calculate the average wear amount of the full-scale prototype and the scaled-down prototype in n wear tests respectively. and S13, take the maximum average wear value According to the formula Solving for the parameter k 02 ; S14, according to parameter k 02 Establish a wear reliability life model for water-lubricated bearings. S15. Based on the actual load P0 and allowable wear amount h0 of the water-lubricated bearing to be tested, the wear life T0 of the water-lubricated bearing to be tested is calculated.

9. A test system for assessing the wear reliability of large water-lubricated bearings, used to implement the test method for assessing the wear reliability of large water-lubricated bearings as described in any one of claims 1 to 8, characterized in that, include: 1) Real-scale prototype testing module, used to conduct functional performance tests and wear and durability tests on real-scale prototypes; 2) Scaled-down sample testing module, used to conduct functional performance tests and wear durability tests on scaled-down samples; 3) Material test block testing module, used to conduct wear model tests, accelerated wear tests and wear durability comparison tests on material test blocks.

10. The large water-lubricated bearing wear reliability assessment test system according to claim 9, characterized in that, The full-scale prototype test module, scaled-down prototype test module, and material block test module all use the same test shaft material, test shaft diameter, cooling water environment, relative sliding speed, test cycle, and test time allocation ratio at each test speed within the test cycle.

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