A method for installing and adjusting a short-span asymmetric load shafting of a ship

Abstract

The application relates to a ship short-span asymmetric load shafting installation adjustment method, which comprises the following steps: connecting each shaft section based on shafting straight alignment requirements to form a short-span shafting; after the ship is launched, checking the intermediate bearing gap and the fit of the short-span shafting, and adjusting the position of the intermediate bearing to meet the position requirements according to the checking results; obtaining original load data of the short-span shafting through a strain method; obtaining a height theoretical value of the intermediate bearing and a height adjustment theoretical value of the thrust bearing based on the original load data and a shafting alignment model; respectively adjusting the height of the intermediate bearing and the thrust bearing to the corresponding height adjustment theoretical values, and obtaining corresponding actual load influence coefficients; adjusting the height of the intermediate bearing and the thrust bearing based on the corresponding height correction values obtained from the actual load influence coefficients of the intermediate bearing and the thrust bearing, and making the inclination state of the short-span shafting meet inclination requirements; and installing adjustment shims on the intermediate bearing and the thrust bearing to complete the installation adjustment of the short-span shafting.

Description

Technical Field

[0001] This application relates to the field of ship installation technology, and in particular to a method for installing and adjusting a short-span asymmetric load shafting system for ships. Background Technology

[0002] Traditional shaft alignment and installation methods that only consider bearing elevation adjustment are suitable for long-span shaft systems without asymmetrical loads, but their application in short-span shaft systems with asymmetrical loads presents the following problems:

[0003] First, in short-span asymmetrical load shaft systems, the initial installation of each bearing is completed after alignment in an unloaded state. Load installation follows the initial bearing installation, and the axis of the shaft changes under load. Therefore, some bearings are prone to becoming unsupported under asymmetrical loads. Since proper shaft alignment requires bearing load measurements to be performed without bearings being unsupported, unsupported bearings directly affect the accuracy of subsequent bearing load measurements. Second, due to the short distance between bearings in short-span asymmetrical load shaft systems, raising some bearings will change the angle between the axis and the bearing, thus affecting the load-bearing state of other bearings. This can easily lead to bearing edge loading. Edge loading alters the bearing's stress position, directly affecting the accuracy of bearing load measurements.

[0004] The two problems with the traditional method of adjusting the shaft system by adjusting the elevation directly affect the final installation state of the shaft system. Some bearings may experience localized overload, while other bearings may experience extremely low load or even be suspended. During operation, the bearings are prone to overheating, vibration, noise and other abnormalities. In extreme cases, the bearings may even burn out.

[0005] For short-span, asymmetrical load shaft systems, the traditional installation method of simply aligning the shaft system cannot ensure that the condition of each bearing meets the design requirements, which can lead to serious equipment failure. Therefore, it is urgent to explore a suitable method for aligning and adjusting short-span, asymmetrical load shaft systems to improve the installation accuracy of the shaft system. Summary of the Invention

[0006] This application provides a method for installing and adjusting short-span asymmetric load shafting systems for ships, which can solve the problem in related technologies that the traditional installation method of simply aligning the shafting system for short-span, asymmetric load shafting systems cannot ensure that the condition of each bearing meets the design requirements.

[0007] This application provides a method for installing and adjusting a short-span asymmetric load shafting system for ships, comprising:

[0008] Based on the requirement of straight alignment of the shaft system, each shaft segment is connected to form a short-span shaft system, which includes intermediate bearings and thrust bearings;

[0009] After the ship is launched, the intermediate bearing clearance and fit of the short span shafting system are checked, and the position of the intermediate bearing is adjusted according to the inspection results to meet the position requirements.

[0010] The original load data of the short-span shaft system was obtained by strain method;

[0011] Based on the original load data and shaft alignment model, the theoretical elevation values ​​of the intermediate bearing and the theoretical elevation adjustment values ​​of the thrust bearing are obtained.

[0012] Adjust the elevations of the intermediate bearing and the thrust bearing to their respective theoretical elevation adjustment values, and obtain their corresponding actual load influence coefficients.

[0013] Adjust the elevation based on the corresponding elevation correction value obtained from the actual load influence coefficient of the intermediate bearing and the thrust bearing, and make the tilt state of the short span shaft system meet the tilt requirements.

[0014] Install adjusting shims on the intermediate bearing and thrust bearing to complete the installation and adjustment of the short-span shaft system.

[0015] In one embodiment, the intermediate bearing includes a first intermediate bearing and a second intermediate bearing;

[0016] Before obtaining the theoretical elevation values ​​of the intermediate bearing and the theoretical elevation adjustment values ​​of the thrust bearing based on the original load data and shaft alignment model, the method further includes:

[0017] Based on the principle of risk control, the elevation of the second intermediate bearing and the thrust bearing were adjusted to complete the installation and adjustment of the short-span shaft system.

[0018] In one implementation, based on the requirement of straight alignment of the shaft system, connecting each shaft segment to form a short-span shaft system specifically includes:

[0019] Based on the requirement of straight alignment of the shaft system, the intermediate bearing and thrust bearing are initially aligned and positioned, and adjustment margin is reserved.

[0020] The remaining shaft system components are installed on the intermediate bearing and thrust bearing to form a short-span shaft system.

[0021] In one implementation, based on the requirement for straight alignment of the shaft system, initial positioning of the intermediate bearing and thrust bearing is performed, specifically including:

[0022] Based on the requirement for straight alignment of the shaft system, the stern shaft in the short-span shaft system is used as the reference, and the intermediate bearings and thrust bearings are initially aligned by offsetting and bending through the flanges of each section from stern to bow.

[0023] In one implementation, a fit inspection of the short-span shafting system is performed after the ship is launched, specifically including:

[0024] The shaft, which is connected to the intermediate bearing and has been coated with colorant in the colored portion, is rotated by a set angle.

[0025] Determine the ratio of the area of ​​the colorant scraped off the colored part to the contact area between the shaft and the intermediate bearing;

[0026] If the ratio is greater than the set threshold, the fit inspection result is qualified;

[0027] If the ratio is less than or equal to the set threshold, the fit inspection result is unqualified.

[0028] In one implementation, the elevations of the intermediate bearing and the thrust bearing are adjusted to their corresponding theoretical elevation adjustment values, and their corresponding actual load influence coefficients are obtained, specifically including:

[0029] Adjust the elevation of the intermediate bearing based on the theoretical value of the intermediate bearing elevation adjustment, and obtain the first load change value of each bearing in the short span shaft system before and after the intermediate bearing elevation adjustment.

[0030] Based on the first load change value of each bearing, the actual load influence coefficient corresponding to the intermediate bearing is obtained.

[0031] Adjust the elevation of the thrust bearing based on the theoretical value of the thrust bearing elevation adjustment, and obtain the second load change value of each bearing in the short span shaft system before and after the thrust bearing elevation adjustment.

[0032] Based on the first load change value and the second load change value of each bearing, the actual load influence coefficient corresponding to the thrust bearing is obtained.

[0033] In one implementation, the elevation is adjusted based on the corresponding elevation correction value obtained from the actual load influence coefficients of the intermediate bearing and the thrust bearing, and the tilt state of the short-span shaft system is made to meet the tilt requirements. Specifically, this includes:

[0034] Based on the actual load influence coefficients of the intermediate bearing and the thrust bearing, the corresponding elevation correction values ​​of the intermediate bearing and the thrust bearing are obtained so that the loads of each bearing in the short-span shaft system meet the design load requirements.

[0035] Adjust the elevation of the intermediate bearing and the thrust bearing based on the corresponding elevation correction values;

[0036] Perform an inspection of the intermediate bearing fit;

[0037] If the fit inspection results are qualified, the tilt state of the short span shaft system meets the tilt requirements;

[0038] If the fit inspection results are unqualified, adjust the height of the intermediate bearing shims to ensure that the loads of each bearing in the short-span shaft system meet the design load requirements.

[0039] In one embodiment, adjusting shims are installed on the intermediate bearing and the thrust bearing to complete the installation and adjustment of the short-span shaft system, specifically including:

[0040] Make the corresponding adjusting shims for the intermediate bearing and thrust bearing;

[0041] Install the corresponding adjusting shims on the intermediate bearing and thrust bearing respectively to complete the installation and adjustment of the short span shaft system.

[0042] In one embodiment, after the ship is launched, the intermediate bearing clearance and fit checks are performed on the short-span shafting system. Based on the check results, the intermediate bearing position is adjusted to meet the positional requirements. Before obtaining the original load data of the short-span shafting system using the strain method, the method further includes:

[0043] Verify the ship's baseline to ensure that the ship's hull attitude meets attitude requirements and the ship's propellers meet water entry requirements.

[0044] In one embodiment, the short-span shaft system further includes a water-lubricated forward stern shaft bearing and a water-lubricated aft stern shaft bearing, wherein the intermediate bearing, thrust bearing, water-lubricated forward stern shaft bearing, and water-lubricated aft stern shaft bearing are connected in sequence.

[0045] At least one set distance exists between multiple adjacent bearings. The set distance is configured such that, after the elevation of the intermediate bearing or thrust bearing is adjusted, the tilt angle of any bearing adjacent to it is greater than a set angle threshold.

[0046] The beneficial effects of the technical solutions provided in this application include:

[0047] This application provides a method for installing and adjusting a short-span asymmetric load shafting system for ships. Based on the traditional method of using the bearing load for reasonable shafting alignment as the installation target, the method dynamically corrects the theoretical value of elevation adjustment based on the actual load influence coefficient to compensate for the deviation between the shafting alignment model and the measured data. It also adds the processes of checking the intermediate bearing clearance, fitting check, and adjusting the tilt of the short-span shafting system. This method can ensure that each bearing is actually bearing the load according to the reasonable alignment requirements, and also ensure the installation clearance of the intermediate bearings and the overall load-bearing state, thereby improving the installation accuracy of the short-span shafting system. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1A flowchart illustrating the installation and adjustment method for a short-span asymmetric load shafting system of a ship, as provided in this application embodiment;

[0050] Figure 2 This is a schematic diagram of the overall short-span shaft system provided in an embodiment of this application.

[0051] In the diagram: 1. First flexible coupling; 2. First intermediate bearing; 3. First intermediate shaft; 4. Second intermediate shaft; 5. Second intermediate bearing; 6. Second flexible coupling; 7. Third intermediate shaft; 8. Thrust bearing; 9. Water-lubricated stern shaft front bearing; 10. Stern shaft; 11. Water-lubricated stern shaft rear bearing; 12. Propeller. Detailed Implementation

[0052] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0053] This application provides a method for installing and adjusting a short-span, asymmetric load shafting system for ships. This method solves the problem in related technologies where installing a short-span, asymmetric load shafting system using traditional methods of simply aligning the shafting system cannot ensure that the condition of each bearing meets the design requirements.

[0054] See Figures 1 to 2 This application provides a method for installing and adjusting a short-span asymmetric load shafting system for ships, comprising:

[0055] 101: Based on the requirement of straight alignment of the shaft system, connect each shaft segment to form a short span shaft system, wherein the short span shaft system includes an intermediate bearing and a thrust bearing 8;

[0056] 102: After the ship is launched, the intermediate bearing clearance and fit of the short span shafting system are checked, and the position of the intermediate bearing is adjusted according to the inspection results to meet the position requirements;

[0057] 103: Obtain the original load data of short-span shaft systems using the strain method;

[0058] 104: Based on the original load data and shaft alignment model, obtain the theoretical elevation values ​​of the intermediate bearing and the theoretical elevation adjustment values ​​of the thrust bearing 8;

[0059] 105: Adjust the elevations of the intermediate bearing and thrust bearing 8 to their corresponding theoretical elevation adjustment values, and obtain their corresponding actual load influence coefficients;

[0060] 106: Adjust the elevation based on the corresponding elevation correction value obtained from the actual load influence coefficient of the intermediate bearing and thrust bearing 8, and make the tilt state of the short span shaft system meet the tilt requirements.

[0061] 107: Install adjusting shims on the intermediate bearing and thrust bearing 8 to complete the installation and adjustment of the short span shaft system.

[0062] In this application, based on the traditional shaft system reasonable alignment bearing load as the installation target, the theoretical value of elevation adjustment is dynamically corrected based on the actual load influence coefficient to compensate for the deviation between the shaft system alignment model and the measured data. In addition, the process of intermediate bearing clearance inspection, fit inspection and short span shaft system tilt adjustment is added. This can not only ensure that each bearing is actually bearing the load according to the reasonable alignment requirements, but also ensure the intermediate bearing installation clearance and overall load condition, thereby improving the installation accuracy of short span shaft systems.

[0063] In this application, the intermediate bearing includes a first intermediate bearing 2 and a second intermediate bearing 5, see [link to application]. Figure 2 As shown, the short-span shaft system also includes a water-lubricated forward stern shaft bearing 9 and a water-lubricated aft stern shaft bearing 11, with the intermediate bearing, thrust bearing 8, water-lubricated forward stern shaft bearing 9, and water-lubricated aft stern shaft bearing 11 connected sequentially. Specifically, the short-span shaft system of this embodiment includes a first flexible coupling 1, a first intermediate bearing 2, a first intermediate shaft 3, a second intermediate shaft 4, a second intermediate bearing 5, a second flexible coupling 6, a third intermediate shaft 7, a thrust bearing 8, a water-lubricated forward stern shaft bearing 9, a stern shaft 10, a water-lubricated aft stern shaft bearing 11, and a propeller 12.

[0064] At least one set distance exists between multiple adjacent bearings. The set distance is configured such that after the elevation of the intermediate bearing or thrust bearing 8 is adjusted, the tilt angle of any bearing adjacent to it is greater than a set angle threshold.

[0065] In other words, the short span of the shaft system means that there is at least one short distance between each bearing. This can lead to a situation where, after calculating the proper alignment of the shaft system and raising a certain bearing, the tilt angle of any adjacent bearing exceeds 3.5 × 10⁻⁶. -4 rad.

[0066] In addition, under asymmetrical loads, such as high-elasticity couplings or clutches, wheel loads, etc., the load difference between two adjacent bearings in the lower part of the shaft system during straight alignment exceeds 60% of the allowable load of either of the two adjacent bearings.

[0067] Based on the above embodiments, in this embodiment, based on the requirement of straight alignment of the shaft system to connect each shaft segment to form a short-span shaft system, the specific steps include 1011 to 1012:

[0068] Step 1011: Based on the requirements for straight alignment of the shaft system, perform initial alignment of the intermediate bearing and thrust bearing 8, and reserve adjustment margin.

[0069] Specifically, during the slipway stage, based on the requirement for straight alignment of the shafting system, the stern shaft 10, positioned with the water-lubricated forward stern shaft bearing 9 and the water-lubricated aft stern shaft bearing 11 in the short-span shafting system, is used as a reference. Initial alignment of the intermediate bearings and thrust bearings 8 is performed from stern to bow through the offset and tortuous sections of the shaft flanges. The intermediate bearings here include the first intermediate bearing 2 and the second intermediate bearing 5. The following requirements also apply to the initial alignment:

[0070] The bolts and bolt holes on the thrust bearing 8, the first intermediate bearing 2, and the second intermediate bearing 5 are all in a state where machining allowances are reserved compared to the final installation state (not finally tightened) in order to facilitate subsequent adjustments.

[0071] Step 1012: Install the remaining shaft system components on the intermediate bearing and thrust bearing 8 to form a short-span shaft system.

[0072] The remaining components of the short-span shaft system are arranged as follows: Figure 2 Install as shown to form a short-span shaft system.

[0073] Based on the above embodiments, in this embodiment, in step 102, the water launching stage needs to be "reasonably calibrated" according to the actual working conditions, and the load distribution is optimized by adjusting the bearing position.

[0074] First, measure the left and right clearances at both ends of the first intermediate bearing 2 and the second intermediate bearing 5. The deviation of the left and right clearances should meet the technical requirements of the intermediate bearings. Then, check the fit between the bearing shells and the shaft of the first intermediate bearing 2 and the second intermediate bearing 5. Specifically, after the ship is launched, a fit inspection of the short-span shafting system is performed, including:

[0075] First, rotate the shaft connected to the intermediate bearing and coated with colorant on the colored part by a set angle: apply lead oxide to the upper cylindrical surface of the intermediate shaft (first intermediate shaft 3, second intermediate shaft 4) connected to the first intermediate bearing 2 and the second intermediate bearing 5, and then rotate the first intermediate shaft 3 and the second intermediate shaft 4 360° by turning the wheel, so that the colored part rotates over the bottom bearing bush.

[0076] Then determine the ratio of the area of ​​the colorant scraped off the colored part to the contact area between the shaft and the intermediate bearing: check the situation of the lead oxide being scraped off the colored part by the bearing bush, and ensure that the area of ​​the lead oxide scraped off part is greater than 75% of the contact area between the first intermediate shaft 3, the second intermediate shaft 4 and the bearing bush.

[0077] If the ratio is greater than the set threshold, the bonding inspection result is qualified; if the ratio is less than or equal to the set threshold, the bonding inspection result is unqualified. That is to say, if the area of ​​the lead oxide scraping strip is greater than 75% of the bonding area between the first intermediate shaft 3, the second intermediate shaft 4 and the bearing bush, it is qualified; if it is less than 75%, the position of the intermediate bearing should be adjusted until the requirement is met. If the bonding inspection result of the first intermediate shaft 3 is unqualified, the position of the first intermediate bearing 2 should be adjusted; if the bonding inspection result of the second intermediate shaft 4 is unqualified, the position of the second intermediate bearing 5 should be adjusted.

[0078] Based on the above embodiments, in this embodiment, after the ship is launched, the intermediate bearing clearance and fit checks are performed on the short-span shafting system. After adjusting the intermediate bearing position to meet the positional requirements based on the check results, and before obtaining the original load data of the short-span shafting system using the strain method, the method further includes:

[0079] Verify the hull baseline to ensure that the ship's hull attitude meets the attitude requirements and the ship's propeller 12 meets the water entry requirements.

[0080] Specifically, before obtaining the original load data of the short-span shafting system using the strain method, the hull attitude must be confirmed and the initial load measurement of the shafting system after launching must be carried out: after launching, the hull baseline must be checked to ensure that the hull attitude meets the requirements of longitudinal and transverse trim less than 1° and that the propeller 12 is fully submerged in water; during the bearing load measurement and subsequent adjustment, welding and hammering operations in the shafting arrangement area should be stopped. After the above conditions are met, the bearing load measurement in the original state is carried out using the strain method to obtain the original load data of the short-span shafting system.

[0081] Furthermore, before obtaining the theoretical elevation values ​​of the intermediate bearing and the thrust bearing 8 based on the original load data and shaft alignment model, the method further includes: based on risk control principles, selecting and adjusting the elevations of the second intermediate bearing 5 and the thrust bearing 8 to complete the short-span shaft system installation adjustment step.

[0082] Given that the water-lubricated aft bearing 11 and water-lubricated forward bearing 9 are external structures and cannot be adjusted, only the thrust bearing 8, the first intermediate bearing 2, and the second intermediate bearing 5 inside the cabin can be adjusted. Furthermore, since adjusting the power plant after launching is difficult, adjusting the first intermediate bearing 2 would directly affect the alignment of the shaft system with the power plant. Adjusting the remaining bearings also meets the design requirements; therefore, its elevation is not adjusted. Based on the bearing load measurement results in the initial state during launching, and with the goal of adjusting each bearing load to within ±15% of the design load, the load influence coefficients of the thrust bearing 8 and the second intermediate bearing 5 obtained from shaft alignment calculations can be used to calculate the theoretical values ​​for the elevation adjustment of the thrust bearing 8 and the second intermediate bearing 5. In this embodiment, considering the actual situation where only one bearing (thrust bearing 8 or the second intermediate bearing 5) needs adjustment, and given the greater complexity of adjusting the thrust bearing 8 in actual operation, a solution of adjusting only the elevation of the second intermediate bearing 5 is preferred.

[0083] Based on the above embodiments, in this embodiment, the elevations of the intermediate bearing and the thrust bearing 8 are adjusted to their corresponding theoretical elevation adjustment values, and their corresponding actual load influence coefficients are obtained, specifically including steps 1051 to 1054:

[0084] Step 1051: Adjust the elevation of the intermediate bearing based on the theoretical value of the intermediate bearing elevation adjustment, and obtain the first load change value of each bearing in the short span shaft system before and after the intermediate bearing elevation adjustment.

[0085] Step 1052: Based on the first load change value of each bearing, obtain the actual load influence coefficient corresponding to the intermediate bearing;

[0086] Specifically, the actual load influence coefficients of the second intermediate bearing 5 and the thrust bearing 8 are carried out in stages from bow to stern. First, the elevation of the second intermediate bearing 5 is adjusted according to the theoretical value of the elevation adjustment. The bearing load after the elevation adjustment of the second intermediate bearing 5 is measured by strain method. The actual load influence coefficient of the second intermediate bearing 5 on all bearings is calculated based on the change value of the load of each bearing before and after the adjustment.

[0087] Step 1053: Adjust the elevation of the thrust bearing 8 based on the theoretical value of the elevation adjustment, and obtain the second load change value of each bearing in the short span shaft system before and after the elevation adjustment of the thrust bearing 8.

[0088] Step 1054: Based on the first load change value and the second load change value of each bearing, obtain the actual load influence coefficient corresponding to the thrust bearing 8.

[0089] Specifically, the elevation of the thrust bearing 8 is adjusted according to the theoretically calculated elevation adjustment amount. The bearing load after the elevation adjustment of the thrust bearing 8 is measured by strain method. Based on the changes in the bearing load after the adjustment of the thrust bearing 8 and the bearing load after the adjustment of the second intermediate bearing 5, the actual load influence coefficient of the thrust bearing 8 on all bearings is calculated.

[0090] Based on the above embodiments, in this embodiment, the elevation is adjusted according to the corresponding elevation correction value obtained based on the actual load influence coefficient of the intermediate bearing and the thrust bearing 8, and the tilt state of the short span shaft system meets the tilt requirements. Specifically, steps 1061 to 1065 are included:

[0091] Step 1061: Based on the actual load influence coefficients of the intermediate bearing and the thrust bearing 8, obtain the elevation correction values ​​corresponding to the intermediate bearing and the thrust bearing 8 so that the loads of each bearing in the short-span shaft system meet the design load requirements.

[0092] Specifically, the elevation adjustment amount is corrected based on the actual load influence coefficient of the second intermediate bearing 5 and the thrust bearing 8 to obtain the elevation correction value, with the goal of adjusting the load of each bearing to within ±15% of the design load.

[0093] Step 1062: Adjust the elevation of the intermediate bearing and thrust bearing 8 based on the elevation correction value corresponding to the intermediate bearing and thrust bearing 8: Fine-tune the elevation of the second intermediate bearing 5 and thrust bearing 8 according to the elevation correction value corresponding to the elevation of the second intermediate bearing 5 and thrust bearing 8.

[0094] Step 1063: Perform intermediate bearing fit inspection: Check the fit between the first intermediate bearing 2 bush and the first intermediate shaft 3 according to the fit inspection steps in Step 102.

[0095] Step 1064: If the fit inspection result is qualified, the tilt state of the short span shaft system meets the tilt requirements.

[0096] Step 1065: If the fit inspection result is not qualified, adjust the height of the intermediate bearing shim so that the load of each bearing in the short span shaft system meets the design load requirements. If the fit inspection requirements in step 102 are not met, the first intermediate bearing 2 can be tilted by adjusting the height of the local shim of the first intermediate bearing 2 to adapt to the tilt angle of the first intermediate bearing 2 caused by the raising of the second intermediate bearing 5.

[0097] Based on the above embodiments, in this embodiment, adjusting shims are installed on the intermediate bearing and the thrust bearing 8 to complete the installation and adjustment of the short-span shaft system, specifically including steps 1071 to 1072:

[0098] Step 1071: Make the corresponding adjusting shims for the intermediate bearing and thrust bearing 8;

[0099] Step 1072: Install the corresponding adjusting shims of the intermediate bearing and thrust bearing 8 onto the intermediate bearing and thrust bearing 8 respectively to complete the installation and adjustment of the short span shaft system.

[0100] This step involves final bearing load measurement and acceptance. Specifically, strain gauges are installed on all bearings in the shafting system (first intermediate bearing 2, second intermediate bearing 5, thrust bearing 8, water-lubricated stern shaft forward bearing 9, and water-lubricated stern shaft aft bearing 11), and real-time load data for each bearing is collected through hydraulic loading or simulation of actual ship operating conditions.

[0101] Compare the measured load with the design load and calculate the deviation rate. The deviation rate must be ≤ ±20%. If the deviation of a bearing exceeds the limit, its elevation must be readjusted. After the standard is met, measure the thickness of the shims for the first intermediate bearing 2, the second intermediate bearing 5, and the thrust bearing 8, and make the shims. The thickness deviation of the shims must be ≤ ±0.03mm. After the shims are made and installed, carry out the final bearing load measurement and acceptance work. The deviation of each bearing load from the design load must be ≤ ±20%.

[0102] The following are specific embodiments of this application:

[0103] Short span axis system Figure 2 The layout is as shown.

[0104] Based on the shaft alignment calculations, the load on the first intermediate bearing 2 is 139.48 kN, the load on the second intermediate bearing 5 is 13.28 kN, and the load on the thrust bearing 8 is 59.58 kN. The load difference between the first intermediate bearing 2 and the second intermediate bearing 5 is 126.21 kN, and the load difference between the second intermediate bearing 5 and the thrust bearing 8 is 46.30 kN. The allowable load for the first intermediate bearing 2 is 129.64 kN, and the allowable load for the second intermediate bearing 5 is 100.59 kN. The thrust bearing 8 has a permissible load of 84 kN. Therefore, the load difference between the first intermediate bearing 2 and the second intermediate bearing 5 exceeds 97.35% of the permissible load of the first intermediate bearing 2 and 125.47% of the permissible load of the second intermediate bearing 5, both exceeding 60% of their respective permissible loads. After reasonable shaft alignment calculations, the second intermediate bearing 5 needs to be raised by 0.7 mm. Calculations show that after raising the second intermediate bearing 5, the rotation angle of the first intermediate bearing 2 will be 7.55 × 10⁻⁶. -4 Radius; the rotation angle of the second intermediate bearing 5 is 3.56 × 10⁻⁶. -5 rad, thrust bearing 8 rotation angle 1.377×10 -4 Therefore, the second intermediate bearing 5 is raised, causing the rotation angle of the first intermediate bearing 2 to be greater than 3.5 × 10 rad. -4 rad. Therefore, the shaft system satisfies the two conditions of short span and asymmetric load shaft system.

[0105] Taking the above example of a short-span asymmetric load shafting system on a ship as an example, the specific steps for shafting installation and adjustment based on reasonable alignment are as follows:

[0106] First, the initial installation of the shaft system is carried out in the slipway stage: In accordance with the requirements for shaft system straight alignment in the slipway stage, the stern shaft 10, which is positioned by the water-lubricated stern shaft forward bearing 9 and the water-lubricated stern shaft aft bearing 11, is used as the reference. The thrust bearing 8, the second intermediate bearing 5 and the first intermediate bearing 2 are aligned from stern to bow by offsetting and tortuous through the flanges of each section. The thrust bearing 8, the first intermediate bearing 2 and the second intermediate bearing 5 are initially positioned, that is, the bolts and bolt holes are in a state that leaves a machining allowance compared to the final installation state.

[0107] After launching, the initial state of the intermediate bearings was confirmed: the left and right clearances at both ends of the first intermediate bearing 2 and the second intermediate bearing 5 were measured. The left and right clearance deviations were required to meet the requirement that the clearance difference at the four locations of the lower bearing bush opening radially at the left front, left rear, right front, and right rear should be ≤0.08mm. Then, the fit between the intermediate bearing bush and the shaft was checked. Specifically, lead oxide was applied to the upper semi-cylindrical surface of the intermediate shaft, and then the intermediate shaft was rotated 360° by turning the wheel so that the colored part passed over the bottom bearing bush. The lead oxide was then checked for being scraped off the colored part by the bearing bush. It should be ensured that the area of ​​the lead oxide scraped off should be greater than 75% of the fit area between the intermediate shaft and the bearing bush. The inspection showed that the left and right clearances of the first intermediate bearing 2 and the second intermediate bearing 5, and the fit of the first intermediate bearing 2 met the requirements, but the fit area of ​​the second intermediate bearing 5 did not meet the 75% requirement. Therefore, the second intermediate bearing 5 was raised on site until the bearing fit area reached approximately 87%.

[0108] Next, the hull attitude was confirmed and initial shaft load measurements were conducted after launching. After launching, the hull baseline was checked to ensure the hull attitude met the requirements of trim and list less than 1° and that propeller 12 was fully submerged. Welding and hammering work in the shafting area should be stopped during bearing load measurements and subsequent adjustments. After these conditions were met, bearing load measurements were conducted in the initial state using the strain method. The measured bearing loads are shown in Table 1.

[0109] Table 1 Initial loads of each bearing

[0110] .

[0111] Then, the theoretical values ​​for bearing elevation adjustment were calculated: Since the aft bearing 11 and the forward bearing 9 of the water-lubricated stern shaft are external structures and cannot be adjusted, only the thrust bearing 8 and intermediate bearings inside the hull can be adjusted. Because the position of the first intermediate bearing 2 at the bow affects the alignment with the power plant, its elevation is not adjusted. Based on the bearing load measurement results in the initial state during the launching phase, and with the goal of adjusting each bearing load to within ±15% of the design load, the theoretical values ​​for the elevation adjustment of the thrust bearing 8 and the second intermediate bearing 5 were calculated using the load influence coefficients of the thrust bearing 8 and the second intermediate bearing 5 obtained from the shaft alignment calculation. The calculated solutions 1 (raising the second intermediate bearing 5 by 0.5mm) and 2 (raising the second intermediate bearing 5 by 0.7mm and the thrust bearing 8 by 0.5mm) both achieved the requirement of adjusting the bearing load to within ±15% of the design load. Considering the more complex adjustment work of thrust bearing 8, scheme 1, which only adjusts the elevation of the second intermediate bearing 5, is adopted. The bearing loads of each bearing in the shaft system reasonable alignment target load and theoretical elevation adjustment scheme are shown in Table 2:

[0112] Table 2. Adjustment Scheme for Target Load and Theoretical Elevation of Shaft System Alignment: Load of Each Bearing

[0113] .

[0114] Next, the actual load influence coefficient of the bearings was obtained by actual measurement: the elevation of the first intermediate bearing 2 was increased by 0.5mm according to the theoretically calculated adjustment amount, and the bearing load after the elevation adjustment of the first intermediate bearing 2 was measured by strain method; the load influence coefficient of the first intermediate bearing 2 on all bearings was calculated based on the load change values ​​of each bearing before and after the adjustment, as shown in Table 3.

[0115] Table 3 shows the influence coefficient of bearing load and actual load after adjusting the height of the first intermediate bearing 2 by 0.5mm.

[0116] .

[0117] Then, the bearing elevation adjustment amount was corrected: based on the measured load influence coefficient of the second intermediate bearing 5, the bearing elevation adjustment amount was calculated, with the goal of adjusting the load of each bearing to within ±15% of the design load. Calculations showed that raising the elevation of the second intermediate bearing 5 by 0.5mm already met the requirement of adjusting to within ±15% of the design load (see Table 4), and no further adjustment of the bearing elevation was necessary.

[0118] Table 4 shows the elevation adjustment of the second intermediate bearing 5 by 0.5 mm, indicating a deviation between the bearing load and the design load.

[0119] .

[0120] Further fine-tuning of the bearing elevations and actual bearing load measurements: Since the adjustment height of the second intermediate bearing 5 according to the theoretical load influence coefficient is consistent with the adjustment amount of the second intermediate bearing 5 according to the actual load influence coefficient, this step directly checks the fit between the bearing shell of the first intermediate bearing 2 and the intermediate shaft. It was found that the first intermediate bearing 2 was not in fit within 2 / 3 of its length. To ensure the fit of the first intermediate bearing 2, the stern end of the first intermediate bearing 2 was raised by 0.3mm to compensate for the problem of the first intermediate bearing 2 tilting too much due to the second intermediate bearing 5 being raised by 0.5mm.

[0121] Finally, the bearing load was measured and accepted under final conditions: the second intermediate bearing 5 was raised by 0.5 mm, and the stern end of the first intermediate bearing 2 was raised by 0.3 mm. The load of each intermediate bearing was measured using the strain method, as shown in Table 5. The measured load of each bearing met the requirement of being ≤ ±20% of the design load. After meeting the standard, the thickness of the adjusting shims for the thrust bearing 8, the second intermediate bearing 5, and the first intermediate bearing 2 was measured and the adjusting shims were fabricated. The fabrication deviation of the adjusting shim thickness was required to be ≤ ±0.03 mm. After the adjusting shims were fabricated and installed, the bearing load was measured under final conditions. The measurement results are shown in Table 5. Therefore, the final measured load of each bearing met the requirement of being ≤ ±20% of the design load, and the acceptance was completed.

[0122] Table 5 Deviations between final bearing loads and design loads

[0123] .

[0124] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0125] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0126] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for installing and adjusting a short-span asymmetric load shafting system for ships, characterized in that, It includes: Based on the requirement of straight alignment of the shaft system, each shaft segment is connected to form a short span shaft system, which includes intermediate bearings and thrust bearings (8). After the ship is launched, the intermediate bearing clearance and fit of the short span shafting system are checked, and the position of the intermediate bearing is adjusted according to the inspection results to meet the position requirements. The original load data of the short-span shaft system was obtained by strain method; Based on the original load data and shaft alignment model, the theoretical elevation values ​​of the intermediate bearing and the theoretical elevation adjustment values ​​of the thrust bearing (8) are obtained. Adjust the elevations of the intermediate bearing and the thrust bearing (8) to their respective theoretical elevation adjustment values, and obtain their corresponding actual load influence coefficients; The elevation is adjusted based on the corresponding elevation correction value obtained from the actual load influence coefficient of the intermediate bearing and the thrust bearing (8), and the tilt state of the short span shaft system meets the tilt requirements. Install adjusting shims on the intermediate bearing and thrust bearing (8) to complete the installation and adjustment of the short span shaft system.

2. The method for installing and adjusting a short-span asymmetric load shafting system of a ship as described in claim 1, characterized in that: The intermediate bearing includes a first intermediate bearing (2) and a second intermediate bearing (5); Before obtaining the theoretical elevation values ​​of the intermediate bearing and the theoretical elevation adjustment values ​​of the thrust bearing (8) based on the original load data and shaft alignment model, the method further includes: Based on the principle of risk control, the elevation of the second intermediate bearing (5) and the thrust bearing (8) were adjusted to complete the installation and adjustment of the short-span shaft system.

3. The method for installing and adjusting a short-span asymmetric load shafting system of a ship as described in claim 1, characterized in that, Based on the requirement of straight alignment of the axis system, the various axis segments are connected to form a short-span axis system, specifically including: Based on the requirement of straight alignment of the shaft system, the intermediate bearing and thrust bearing (8) are initially aligned and positioned, and an adjustment margin is reserved. The remaining shaft components are installed on the intermediate bearing and thrust bearing (8) to form a short-span shaft system.

4. The method for installing and adjusting a short-span asymmetric load shafting system of a ship as described in claim 3, characterized in that, Based on the requirement for straight alignment of the shaft system, the intermediate bearing and thrust bearing (8) are initially aligned and positioned, specifically including: Based on the requirement of straight alignment of the shaft system, the stern shaft (10) in the short span shaft system is used as the reference, and the intermediate bearing and thrust bearing (8) are initially positioned by offsetting and bending through the flanges of each section from stern to bow.

5. The method for installing and adjusting a short-span asymmetric load shafting system of a ship as described in claim 1, characterized in that, After the ship is launched, a fit inspection is performed on the short-span shafting system, which specifically includes: The shaft, which is connected to the intermediate bearing and has been coated with colorant in the colored portion, is rotated by a set angle. Determine the ratio of the area of ​​the colorant scraped off the colored part to the contact area between the shaft and the intermediate bearing; If the ratio is greater than the set threshold, the fit inspection result is qualified; If the ratio is less than or equal to the set threshold, the fit inspection result is unqualified.

6. The method for installing and adjusting a short-span asymmetric load shafting system of a ship as described in claim 1, characterized in that, Adjust the elevations of the intermediate bearing and the thrust bearing (8) to their respective theoretical elevation adjustment values, and obtain their corresponding actual load influence coefficients, specifically including: Adjust the elevation of the intermediate bearing based on the theoretical value of the intermediate bearing elevation adjustment, and obtain the first load change value of each bearing in the short span shaft system before and after the intermediate bearing elevation adjustment. Based on the first load change value of each bearing, the actual load influence coefficient corresponding to the intermediate bearing is obtained. Adjust the elevation of the thrust bearing (8) based on the theoretical value of the elevation adjustment, and obtain the second load change value of each bearing in the short span shaft system before and after the elevation adjustment of the thrust bearing (8). Based on the first load change value and the second load change value of each bearing, the actual load influence coefficient corresponding to the thrust bearing (8) is obtained.

7. The method for installing and adjusting a short-span asymmetric load shafting system of a ship as described in claim 1, characterized in that, The elevation is adjusted based on the corresponding elevation correction value obtained from the actual load influence coefficient of the intermediate bearing and the thrust bearing (8), and the tilt state of the short-span shaft system meets the tilt requirements, specifically including: Based on the actual load influence coefficients of the intermediate bearing and the thrust bearing (8), the corresponding elevation correction values ​​of the intermediate bearing and the thrust bearing (8) are obtained so that the loads of each bearing in the short span shaft system meet the design load requirements. Adjust the elevation of the intermediate bearing and the thrust bearing (8) based on the elevation correction values ​​corresponding to the intermediate bearing and the thrust bearing (8); Perform an inspection of the intermediate bearing fit; If the fit inspection results are qualified, the tilt state of the short span shaft system meets the tilt requirements; If the fit inspection results are unqualified, adjust the height of the intermediate bearing shims to ensure that the loads of each bearing in the short-span shaft system meet the design load requirements.

8. The method for installing and adjusting a short-span asymmetric load shafting system of a ship as described in claim 1, characterized in that, Install adjusting shims on the intermediate bearing and thrust bearing (8) to complete the installation and adjustment of the short-span shaft system, specifically including: Make the corresponding adjusting shims for the intermediate bearing and thrust bearing (8); Install the corresponding adjusting shims of the intermediate bearing and the thrust bearing (8) onto the intermediate bearing and the thrust bearing (8) respectively to complete the installation and adjustment of the short span shaft system.

9. The method for installing and adjusting a short-span asymmetric load shafting system of a ship as described in claim 1, characterized in that: After the ship is launched, the intermediate bearing clearance and fit checks are performed on the short-span shafting system. Based on the check results, the intermediate bearing positions are adjusted to meet the requirements. Before obtaining the original load data of the short-span shafting system using the strain method, the method further includes: Verify the hull baseline to ensure that the ship's hull attitude meets the attitude requirements and the ship's propeller (12) meets the water entry requirements.

10. The method for installing and adjusting a short-span asymmetric load shafting system of a ship as described in claim 1, characterized in that: The short span shaft system also includes a water-lubricated stern shaft front bearing (9) and a water-lubricated stern shaft rear bearing (11), and the intermediate bearing, thrust bearing (8), water-lubricated stern shaft front bearing (9) and water-lubricated stern shaft rear bearing (11) are connected in sequence. At least one set distance exists between multiple adjacent bearings. The set distance is configured such that after the elevation of the intermediate bearing or thrust bearing (8) is adjusted, the tilt angle of any bearing adjacent to it is greater than a set angle threshold.

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