Tool for measuring abrasion loss of bearing bush of water-lubricated bearing engineering prototype

Abstract

The utility model relates to the field of transmission system detection, and particularly discloses a bearing bush abrasion loss measuring tool for a water-lubricated bearing engineering prototype, which comprises a shell of the water-lubricated bearing engineering prototype and a bearing bush positioned in the shell, and a through measuring hole is arranged at the highest point of the top of the shell in the vertical direction of the bearing bush. The lower section of the positioning block is inserted into the upper section of the measuring hole, the upper section is a flange section positioned outside the measuring hole, and a through inner hole is also formed in the positioning block. The device is simple in structure, easy to operate, high in precision and low in equipment investment and test cost.

Description

Technical Field

[0001] This utility model relates to the field of transmission system testing, specifically a tooling for measuring the wear of a water-lubricated bearing prototype. Background Technology

[0002] Water-lubricated bearings, as important components of marine propulsion systems, primarily utilize water or water-based lubricants as the lubrication medium to reduce frictional resistance and bearing wear. During the design process, water-lubricated bearings require testing the bearing wear of engineering prototypes.

[0003] CN109813232A discloses a method for detecting the wear of sliding bearings based on the length of a fiber Bragg grating. This method involves inserting the wear detection end of a grating wear sensor into a wear detection hole in the bearing bush, periodically obtaining data on the change in the length of the grating region to determine the wear amount. However, this method focuses more on obtaining wear information at the location where the wear detection end is embedded, making it difficult to obtain overall bearing bush wear data. Furthermore, it requires pre-embedding the wear detection end of the grating wear sensor during bearing bush fabrication, resulting in complex processes and high testing costs.

[0004] CN114518084A discloses a method for simultaneous ultrasonic measurement of the lubricating film thickness and bearing liner wear in sliding bearings. Utilizing the characteristic that liner wear only changes the phase of the reference signal without altering its amplitude, a method is established to simultaneously obtain the sliding bearing oil film thickness and liner wear degree. First, based on the amplitude ratio of the reflected signal from the worn oil film to the reference signal before wear, the oil film thickness is calculated using an amplitude model of the ultrasonic reflection coefficient. Then, based on the phase difference between the reflected signal from the worn oil film and the reference signal before wear, a wear model is established for different film thicknesses to quantify the wear degree of the sliding bearing liner. This method requires specialized operators to perform the testing with ultrasonic equipment, resulting in high equipment costs, complex operation, and a high degree of specialization, thus limiting its applicability.

[0005] Therefore, there is a need for a method that is easy to operate, highly accurate, and requires low equipment investment and testing costs to measure bearing wear. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned technical problems and provide a tooling for measuring the wear of water-lubricated bearing prototype bearing bushes that is simple in structure, easy to operate, highly accurate, and has low equipment investment and testing costs.

[0007] This utility model measuring fixture includes a housing of a water-lubricated bearing engineering prototype and a bearing bush located inside the housing. A through measuring hole is provided at the highest point of the top of the housing and the bearing bush in the vertical direction. The lower section of the positioning block is inserted into the upper section of the measuring hole. The upper section is a flange section located outside the measuring hole. The positioning block also has a through inner hole. The distance rod is inserted into the measuring hole through the inner hole of the positioning block.

[0008] Preferably, the lower section of the positioning block is provided with an external thread, and the upper section of the measuring hole is provided with an internal thread. During measurement, the lower section of the positioning block is threadedly connected to the upper section of the measuring hole. Before the test, a plug is used to thread-connect the upper section of the measuring hole to seal the measuring hole.

[0009] Preferably, the upper end face of the spacer is a plane and the lower end face is a sphere.

[0010] Preferably, the periphery of the measuring hole on the housing is provided with a countersinking hole, and the bottom of the flange section of the upper part of the positioning block is located in the countersinking hole.

[0011] Preferably, the outer diameter of the spacer rod is 0.1 to 0.2 mm smaller than the inner diameter of the positioning block.

[0012] Preferably, the upper end of the spacer rod extends out of the measuring hole and is lower than the top surface of the positioning block flange section.

[0013] The specific measurement method is as follows:

[0014] 1. Before the test, the stern shaft is installed into the bearing bush. Under the action of gravity, the bottom outer circular surface of the stern shaft contacts the lower surface of the inner circular surface of the bearing bush, and a gap δ is left between the top outer circular surface of the stern shaft and the upper surface of the inner circular surface of the bearing bush.

[0015] 2. Insert the lower section of the positioning block into the measuring hole, and insert the distance rod through the inner hole of the positioning block. At this time, the lower end of the distance rod is in contact with the outer circular surface of the top of the stern shaft, and the upper end of the distance rod is lower than the top surface of the flange section of the positioning block.

[0016] 3. Using a digital depth micrometer, align the base of the digital depth micrometer with the top surface of the flange section of the positioning block, insert the measuring rod of the digital depth micrometer into the inner hole of the positioning block, and have the end of the measuring rod contact the upper end of the distance measuring rod. Measure the distance from the upper end of the distance measuring rod to the top surface of the flange section of the positioning block to obtain the first measurement value X1.

[0017] 4. Remove the digital depth micrometer, positioning block, and distance rod, seal the measuring hole, and drive the stern shaft for a long-term operation test; after the test, unseal the measuring hole, reinsert the positioning block, and repeat steps two and three to obtain the second measurement value X2;

[0018] V. Calculate the wear amount of the water-lubricated shaft bearing: X = X2 - X1.

[0019] Preferably, in steps three and four, the stern shaft is rotated uniformly N times, with an angle M each time. The distance from the upper end of the spacer rod to the top surface of the flange section of the positioning block is then measured to obtain N+1 measurement values. The arithmetic mean of these measurements is then taken as the final first measurement value X1 and the second measurement value X2.

[0020] Beneficial effects:

[0021] The measuring fixture of this invention is extremely simple and reusable. It uses a positioning block to accurately position the distance measuring rod. Before and after the test, the distance measuring rod is used to obtain the change in the gap δ between the outer surface of the stern shaft top and the upper surface of the inner surface of the bearing bush. This change is reflected in the change in the distance from the upper end of the distance measuring rod to the top surface of the flange section of the positioning block, i.e., the difference between X1 and X2. This data can be accurately measured using a digital depth micrometer. This difference is actually the wear amount X of the water-lubricated bearing bush. The entire measurement and calculation process is extremely simple and can be operated by ordinary workers. It does not require pre-embedded wear detection ends during bearing bush manufacturing, nor does it require professional operators skilled in ultrasonic testing. It does not involve complex signal reading, conversion, or calculation processes, making it easy to operate, highly accurate, and with low equipment investment and testing costs. This invention has a simple structure, is easy to operate, highly accurate, and has low equipment investment and testing costs. Attached Figure Description

[0022] Figure 1 This is an assembly drawing of the measuring fixture of this utility model.

[0023] Figure 2 This is a schematic diagram of the positioning block.

[0024] Figure 3 This is a schematic diagram of the installation of the measuring hole.

[0025] Figure 4 This is a schematic diagram of the installation of the spacer rod.

[0026] Figure 5 This is a cross-sectional view of the stern shaft and bearing.

[0027] Among them, 1. Stern shaft; 2. Bearing bush; 3. Housing; 3-1. Countersunk hole; 4. Positioning block; 4-1. Flange section; 4-2. Lower section; 4-3. Inner hole; 5. Displacement rod; 6. Measuring hole; 6-1. Internal thread. Detailed Implementation

[0028] The present invention will be further explained below with reference to the accompanying drawings:

[0029] See Figures 1-5 The measuring fixture includes the housing 3 of the water-lubricated bearing engineering prototype and the bearing bush 2 located inside the housing 3. A through measuring hole 6 is provided at the highest point of the top of the housing 3 and the bearing bush 2 in the vertical direction. The upper section of the positioning block 4 is a flange section 4-1, the outer diameter of which is larger than the diameter of the measuring hole 6 and is located outside the measuring hole 6. The lower section 4-2 is inserted into the measuring hole 6. The lower section 4-2 is provided with external threads, and the upper section of the measuring hole 6 is provided with internal threads 6-1. The two are connected by threads.

[0030] The positioning block 4 also has a through inner hole 4-3. The distance measuring rod 5 is inserted into the measuring hole 6 through the inner hole 4-3 of the positioning block 4 and positioned therein. Preferably, the outer diameter of the distance measuring rod 5 is 0.1-0.2 mm smaller than the inner diameter of the positioning block 4 to maintain the verticality of the distance measuring rod 5 as much as possible and improve the detection accuracy. Preferably, the upper end face of the distance measuring rod 5 is a plane, which can better match the end plane of the measuring rod of the digital depth micrometer. The lower end face of the distance measuring rod 5 is a spherical surface. Considering the characteristic that the outer circle of the stern shaft 1 is an arc surface, point contact is used instead of surface contact, which can further reduce interference and improve measurement accuracy.

[0031] An internal thread 6-1 is provided on the upper section of the measuring hole 6. During measurement, the positioning block 4 can be quickly inserted and positioned into the measuring hole 6. Before the test, after removing the positioning block 4 and the spacer rod 5, the upper section of the measuring hole 6 can also be connected by a screw plug to quickly seal the measuring hole 6 in preparation for the test.

[0032] In another embodiment, the periphery of the measuring hole 6 on the housing 3 is provided with a countersunk hole 3-1, and the bottom of the flange section 4-1 of the upper section of the positioning block 4 is located in the countersunk hole 3-1, so that the positioning block 3 is limited from the top of the housing 3, which facilitates quick positioning.

[0033] In another embodiment, the upper end of the spacer rod 5 extends out of the measuring hole 6 but is lower than the top surface of the flange section 4-1 of the positioning block 4. During measurement, the upper end of the spacer rod 5 being lower than the top surface of the flange section 4-1 of the positioning block 4 allows for convenient measurement using a digital depth micrometer. After the measurement is completed, the depth micrometer and the positioning block 4 are removed in sequence. The upper end of the spacer rod 5 extending out of the measuring hole 5 allows for convenient and quick removal of the spacer rod 5. Then, a screw plug is inserted to connect the upper section of the measuring hole 6, quickly sealing the measuring hole 6 in preparation for the test.

[0034] Measurement method:

[0035] Before the test, the lower section 4-2 of the positioning block 4 is placed into the measuring hole 6. The positioning block 4 is rotated so that the external thread of the lower section 4-2 is threadedly connected to the internal thread 6-1 of the upper section of the measuring hole 6, and at the same time, the bottom surface of the flange section 4-1 of the positioning block 4 is aligned with the bottom plane of the countersunk hole 3-1 of the water-lubricated bearing engineering prototype housing. Insert the spacer rod 5 through the inner hole 4-3 of the positioning block 4. At this time, the lower end (spherical surface) of the spacer rod 5 is in contact with the outer circular surface of the top of the stern shaft 1, and the upper end of the spacer rod 5 is lower than the top surface of the flange section 4-1 of the positioning block 4. Use a digital depth micrometer, with the bottom surface of the base of the digital depth micrometer flush with the top surface of the flange section 4-1 of the positioning block 4. Insert the measuring rod of the digital depth micrometer through the inner hole 4-3 of the positioning block 4, with the end of the measuring rod in contact with the upper end of the spacer rod 5. Measure the distance from the upper end of the spacer rod 5 to the top surface of the flange section 4-1 of the positioning block 4 to obtain the first measurement value. Multiple measurements can be taken and recorded as needed (a total of 3 measurements are taken in this embodiment). Mark the outer surface of the stern shaft 1 with a marker, with one line evenly spaced every 90° along the circumference. Rotate the stern shaft 3 times evenly, each time rotating it 90°, and measure the first measurement three times each time, obtaining a total of 3*(3+1) sets of data. Take the arithmetic mean of the 12 sets of data as the first measurement value X1.

[0036] After the measurement is completed, remove the positioning block 4 first, then remove the measuring rod 5. Seal the measuring hole 6 with a screw plug and conduct a long-term operation test.

[0037] After the test is stopped, the screw plug is removed again, and the above measurement steps are repeated to obtain the second measurement value X2. The wear amount of the water-lubricated shaft bearing is calculated as X = X2 - X1.

[0038] The following example uses the measurement of bearing wear in a water-lubricated bearing prototype to illustrate the specific measurement steps:

[0039] Before the 1000-hour alternating speed cyclic long-term operation test, marks were made evenly on the circumference of the stern shaft end face (0°, 90°, 180°, 270°). Following the aforementioned method, the stern shaft was positioned at the 0°, 90°, 180°, and 270° positions relative to the measuring hole in the water-lubricated bearing housing. The distance from the upper end face of the positioning block to the upper end face of the measuring rod was measured using a depth micrometer and recorded (a total of four positions, measured three times for each position, for a total of 12 data points, as shown in the table below). The arithmetic mean X1 = 6.350 mm was taken. After measurement, the positioning block 4 was removed first, followed by the measuring rod 5. The measuring hole 6 was sealed with a screw plug, and the stern shaft was driven for a 1000-hour alternating speed cyclic operation test, with each cycle lasting 100 hours, for a total of 10 cycles. After the 1000-hour alternating speed cycle long-term operation test was stopped, the screw plug was removed again. The stern shaft was placed at 0°, 90°, 180°, and 270° in the measuring hole position of the water-lubricated bearing housing. Using the above method, the distance from the upper end face of the positioning block to the upper end face of the measuring rod was measured with a depth micrometer and recorded (a total of four positions, three measurements for each position, for a total of 12 data points, as shown in the table below). The arithmetic mean X2 = 6.365 mm was taken. The wear amount X = X2 - X1, and the calculated wear amount X value is 0.015 mm.

[0040]

Claims

1. A water-lubricated bearing engineering prototype bushing wear amount measuring tool, characterized by, The prototype includes a housing of a water-lubricated bearing and a bearing bush located inside the housing. A through measuring hole is provided at the highest point of the top of the housing and the bearing bush in the vertical direction. The lower section of the positioning block is inserted into the upper section of the measuring hole. The upper section is a flange section located outside the measuring hole. The positioning block also has a through inner hole. The spacer rod is inserted into the measuring hole through the inner hole of the positioning block.

2. The water-lubricated bearing pilot bushing wear measurement fixture of claim 1, wherein, The lower section of the positioning block is provided with external threads, and the upper section of the measuring hole is provided with internal threads. During measurement, the lower section of the positioning block is threadedly connected to the upper section of the measuring hole. Before the test, a plug is used to thread-connect the upper section of the measuring hole to seal the measuring hole.

3. The water-lubricated bearing pilot bushing wear measurement fixture of claim 1, wherein, The upper end face of the spacer is a plane, and the lower end face is a sphere.

4. The water-lubricated bearing pilot bushing wear measurement fixture of claim 1, wherein, The periphery of the measuring hole on the housing is provided with a countersinking hole, and the bottom of the flange section of the upper part of the positioning block is located in the countersinking hole.

5. The water-lubricated bearing pilot bushing wear measurement fixture of claim 1, wherein, The outer diameter of the spacer rod is 0.1 to 0.2 mm smaller than the inner diameter of the positioning block.

6. The water-lubricated bearing engineering prototype bushing wear measurement tool of any one of claims 1-5, wherein, The upper end of the distance measuring rod extends out of the measuring hole and is lower than the top surface of the positioning block flange section.

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