Method for centering ship shafting provided with flange connecting bolts

Abstract

The invention discloses a method for centering a ship shafting provided with a flange connecting bolt, and the method specifically comprises the following steps: supporting the ship shafting to be centered through a temporary support, and enabling the bending and deviation of a flange to meet the design requirements; adjusting the position of the host to enable the bending and deviation of the flange to meet the design requirements; connecting bolts of a shafting flange are installed, nuts are tightened to enable the flange to be connected and fixed, the load of a bearing is measured, the measured load of the bearing is compared with a theoretical load value, when the measured load of the bearing exceeds + / -20% of the theoretical load value, alignment is not successful, a shafting alignment calculation book is restarted, and a new theoretical load value of the bearing is generated; and the shaft system bearing load is readjusted and measured without dismounting the mounted shaft system flange connecting bolts and nuts. According to the method, shafting alignment is carried out without dismounting the connecting bolts of the shafting flange, the original states of the propeller shaft and the intermediate shaft are kept, and the original state of the intermediate bearing can be kept to a large extent.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of shipbuilding, and particularly relates to a method for shaft alignment of a ship with installed flange connecting bolts. BACKGROUND

[0002] Due to the possible inaccuracy of the original version of the shaft alignment calculation book, especially the "GAP" and "SAG" of the shaft flange and the theoretical load value of the shaft bearing, the shaft alignment may fail after the shaft flange is connected with bolts according to the inaccurate shaft alignment calculation book. Generally, the connecting bolts and nuts of the shaft flange need to be removed, and the shaft alignment needs to be performed again, which involves a large amount of work and a long time. The present application can maintain the original state of the shaft to a large extent, does not remove the installed shaft flange connecting bolts and nuts, can greatly affect the production progress on site, and saves the shipbuilding cost and time. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art, and provides a method for shaft alignment of a ship with installed flange connecting bolts. The method of the present application performs shaft alignment without removing the connecting bolts of the shaft flange, maintains the original state of the propeller shaft and the intermediate shaft to a large extent, maintains the original state of the intermediate bearing to a large extent, shortens the production progress on site, greatly reduces the workload of remedial work after the shaft alignment fails, and saves the shipbuilding cost and time.

[0004] In order to achieve the above-mentioned application purposes, the technical solutions provided by the present application patent are as follows:

[0005] A method for shaft alignment of a ship with installed flange connecting bolts, which specifically comprises the following steps:

[0006] S1, supporting the ship shaft to be aligned by temporary support, adjusting the height of the second intermediate shaft until the GAP and SAG of the propeller shaft front flange and the second intermediate shaft rear flange meet the design requirements;

[0007] S2, adjusting the height of the first intermediate shaft, and the GAP and SAG of the second intermediate shaft front flange and the first intermediate shaft rear flange meet the design requirements;

[0008] S3, adjusting the position of the main engine until the GAP and SAG of the first intermediate shaft front flange and the main engine output end flange meet the design requirements;

[0009] S4. Install the connecting bolts of the shaft flange and tighten the nuts to fix the flange connection. Measure the loads of the stern tube front bearing, intermediate bearing, main engine MB1 and the two bearings at the front of the shaft. Compare the measured bearing loads with the theoretical load values. If the measured bearing load exceeds ±20% of the theoretical load value, the alignment is unsuccessful. Recalculate the shaft alignment and generate new theoretical load values ​​for the above bearings.

[0010] S5. Without removing the installed shaft flange connecting bolts and nuts, repeat S2 and S3 to readjust and measure the above shaft bearing load according to the optimized shaft alignment calculation sheet and the optimized bearing theoretical load value. When the measured actual shaft bearing load does not exceed ±20% of the optimized bearing theoretical load value, the shaft alignment is successful.

[0011] Furthermore, at least one temporary support is provided on one side of the second intermediate shaft, and at most two temporary supports are provided. The bending and offset of the propeller shaft front flange and the second intermediate shaft rear flange are ±0.05mm, and the left and right deviation of the flanges is ±0.05mm. The stern tube bearing includes a stern tube front bearing and a stern tube rear bearing.

[0012] Furthermore, at least one temporary support is provided on one side of the first intermediate shaft, and at most two temporary supports are provided. The bending and offset of the front flange of the second intermediate shaft and the rear flange of the first intermediate shaft are ±0.05mm, and the left and right deviation of the flanges is ±0.05mm.

[0013] Furthermore, the hydraulic adjustment tool adjusts the position of the main unit until the bending and offset of the front flange of the first intermediate shaft and the output flange of the main unit meet the design requirements. The bending and offset of the front flange of the first intermediate shaft and the output flange of the main unit is ±0.05mm, and the left and right deviation of the flange is usually ±0.05mm. The position of the main unit is fixed using a mechanical adjustment tool.

[0014] Furthermore, the connecting bolts of the mounting shaft flange are reamed bolts or hydraulic bolts.

[0015] Based on the above technical solution, the method for aligning the shafting of a ship with installed flange connection bolts, as described in this invention patent, has achieved the following technical advantages through practical application:

[0016] 1. This invention provides a method for aligning ship shafting with pre-installed flange bolts. By aligning the shafting without disassembling the flange bolts, the original state of the propeller shaft, intermediate shaft, and intermediate bearings is largely preserved. This shortens on-site production time and significantly reduces remedial work in case of unsuccessful shaft alignment, saving shipbuilding costs and time. Attached Figure Description

[0017] Fig. 1 This is a flowchart of the shaft alignment process in a method for aligning a ship shafting system with flanged connecting bolts installed, according to the present invention.

[0018] Fig. 2 This is a schematic diagram of shaft alignment and temporary support arrangement in a method for aligning a ship shafting system with installed flange connection bolts according to the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific examples shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0020] Example 1

[0021] like Figs. 1-2 As shown, a method for aligning a ship shafting system with flanged connecting bolts is described, the method specifically including the following steps:

[0022] S1, support the ship's shafting system under calibration with temporary support 3, and adjust the height of the second intermediate shaft 4 until the bending and offset of the front flange of the propeller shaft and the rear flange of the second intermediate shaft 4 meet the design requirements.

[0023] S2, adjust the height of the first intermediate shaft 5, and ensure that the bending and offset of the front flange of the second intermediate shaft 4 and the rear flange of the first intermediate shaft 5 meet the design requirements;

[0024] S3, adjust the position of the main unit until the bending and offset of the front flange of the first intermediate shaft 5 and the output flange of the main unit meet the design requirements;

[0025] S4. Install the connecting bolts of the shaft flange and tighten the nuts to fix the flange connection. Measure the loads of the stern tube front bearing, intermediate bearing, main engine MB1 and the two bearings at the front of the shaft. Compare the measured bearing loads with the theoretical load values. If the measured bearing load exceeds ±20% of the theoretical load value, the alignment is unsuccessful. Recalculate the shaft alignment and generate new theoretical load values ​​for the above bearings.

[0026] S5. Without removing the installed shaft flange connecting bolts and nuts, repeat S2 and S3 to readjust and measure the above shaft bearing load according to the optimized shaft alignment calculation sheet and the optimized bearing theoretical load value. When the measured actual shaft bearing load does not exceed ±20% of the optimized bearing theoretical load value, the shaft alignment is successful.

[0027] At least one temporary support 3 is provided on one side of the second intermediate shaft 4, and at most two temporary supports 3 are provided. The bending and offset of the front flange of the propeller shaft and the rear flange of the second intermediate shaft 4 are ±0.05mm, and the left and right deviation of the flange is ±0.05mm. The stern tube bearing includes a front stern tube bearing 2 and a rear stern tube bearing 1.

[0028] At least one temporary support 3 is provided on one side of the first intermediate shaft 5, and at most two temporary supports 3 are provided. The bending and offset of the front flange of the second intermediate shaft 4 and the rear flange of the first intermediate shaft 5 are ±0.05mm, and the left and right deviation of the flanges is ±0.05mm.

[0029] The hydraulic adjustment tool adjusts the position of the main unit until the bending and offset of the front flange of the first intermediate shaft 5 and the output flange of the main unit meet the design requirements. The bending and offset of the front flange of the first intermediate shaft 5 and the output flange of the main unit is ±0.05mm, and the left and right deviation of the flange is usually ±0.05mm. The position of the main unit is fixed by a mechanical adjustment tool.

[0030] The connecting bolts for the mounting shaft flange are reamed bolts or hydraulic bolts.

[0031] Example 2

[0032] A remedial method for unsuccessful shaft alignment during ship construction includes the following steps:

[0033] Step 1: Based on the original shaft alignment calculation sheet of a certain ship, apply a downward temporary external force F to the front flange of the propeller shaft. Select and measure the actual temperature during shaft alignment as 20℃. Adjust the height of the temporary support 3 on the second intermediate shaft 4 and the second intermediate shaft 4 until the "bending (GAP = 0.27mm)" and "offset (SAG = 0.96mm)" of the front flange of the propeller shaft and the rear flange of the second intermediate shaft 4 meet the design requirements; the tolerances of "bending (GAP)" and "offset (SAG)" meet the specifications or design requirements, and the left and right deviations of the flanges meet the specifications or design requirements.

[0034] Step 2: Adjust the height of the temporary support 3 on the first intermediate shaft 5 and the first intermediate shaft 5 until the "GAP" and "SAG" of the front flange of the second intermediate shaft 4 and the rear flange of the first intermediate shaft 5 meet the design requirements; the tolerances of "GAP = 0.72mm" and "SAG = 1.62mm" meet the specifications or design requirements, and the left and right deviations of the flanges meet the specifications or design requirements.

[0035] Step 3: Use a hydraulic adjusting jacking tool to adjust the position of the main unit until the "bend (GAP = 0.16mm)" and "offset (SAG = 1.72mm)" of the front flange of the first intermediate shaft 5 and the output flange of the main unit meet the design requirements. Use a mechanical adjusting (locking) tool to effectively fix the position of the main unit, ensuring that the position of the main unit and the "bend (GAP)" and "offset (SAG)" remain unchanged.

[0036] Step 4: According to the shaft system layout diagram and the requirements for shaft system flange connection bolt installation, use reamed bolts to install the connection bolts and nuts of the shaft system flange, and tighten the nuts according to the required tightening method, with a tightening torque of 5000 NM, etc.

[0037] Step 5: Measure the loads of the stern tube forward bearing, intermediate bearing, main engine MB1, and the two foremost bearings. The calculated loads for these bearings are 350KN, 500KN, and 400KN, respectively. The calculated results for the stern tube forward bearing and intermediate bearing exceed the theoretical load values ​​by ±20% from the original version of the shaft alignment calculation book, therefore the alignment is unsuccessful.

[0038] Step Six: Optimize the original shaft alignment calculation sheet to generate new theoretical load values ​​for the stern tube forward bearing and intermediate bearing: 300KN, 400KN, and 300KN, respectively. Without removing the installed shaft flange connecting bolts and nuts, readjust and measure the loads of the stern tube forward bearing and intermediate bearing according to the optimized shaft alignment calculation sheet and the optimized bearing theoretical load values: 355KN, 470KN, and 350KN, respectively. The actual loads of the shaft bearings do not exceed ±20% of the optimized bearing theoretical load values, and the final shaft alignment is successful.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for aligning a ship's shafting with flanged connecting bolts already installed, characterized in that, The method specifically includes the following steps: S1, support the ship's shafting system under calibration with temporary supports, and adjust the height of the second intermediate shaft until the bending and offset of the propeller shaft front flange and the second intermediate shaft rear flange meet the design requirements. S2, adjust the height of the first intermediate shaft, and ensure that the bending and offset of the front flange of the second intermediate shaft and the rear flange of the first intermediate shaft meet the design requirements; S3, Adjust the position of the main unit until the bending and offset of the front flange of the first intermediate shaft and the output flange of the main unit meet the design requirements; S4. Install the connecting bolts of the shaft flange and tighten the nuts to fix the flange connection. Measure the loads of the stern tube front bearing, intermediate bearing, main engine MB1 and the two bearings at the front of the shaft. Compare the measured bearing loads with the theoretical load values. If the measured bearing load exceeds ±20% of the theoretical load value, the alignment is unsuccessful. Recalculate the shaft alignment and generate new theoretical load values ​​for the above bearings. S5. Without removing the installed shaft flange connecting bolts and nuts, repeat S2 and S3 to readjust and measure the above shaft bearing load according to the optimized shaft alignment calculation sheet and the optimized bearing theoretical load value. When the measured actual shaft bearing load does not exceed ±20% of the optimized bearing theoretical load value, the shaft alignment is successful.

2. The method for aligning a ship shafting system with flanged connecting bolts as described in claim 1, characterized in that, At least one temporary support is provided on one side of the second intermediate shaft, and at most two temporary supports are provided. The bending and offset of the front flange of the propeller shaft and the rear flange of the second intermediate shaft are ±0.05mm, and the left and right deviation of the flange is ±0.05mm. The stern tube bearing includes a front stern tube bearing and a rear stern tube bearing.

3. A method for aligning a ship shafting system with installed flange connection bolts according to claim 1, characterized in that, At least one temporary support is provided on one side of the first intermediate shaft, and at most two temporary supports are provided. The bending and offset of the front flange of the second intermediate shaft and the rear flange of the first intermediate shaft are ±0.05mm, and the left and right deviation of the flanges is ±0.05mm.

4. A method for aligning a ship shafting system with flanged connecting bolts installed, as described in claim 1, characterized in that... The hydraulic adjustment tool adjusts the position of the main unit until the bending and offset of the front flange of the first intermediate shaft and the output flange of the main unit meet the design requirements. The bending and offset of the front flange of the first intermediate shaft and the output flange of the main unit is ±0.05mm, and the left and right deviation of the flange is usually ±0.05mm. The position of the main unit is fixed by a mechanical adjustment tool.

5. A method for aligning a ship shafting system with installed flange connection bolts according to claim 1, characterized in that, The connecting bolts for the mounting shaft flange are reamed bolts or hydraulic bolts.

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