Method and process of ship stern tube boring
On site line boring machine equipment helps the heavy duty shipyard and power plant to cut the down time, save the transportation cost and earn the profit mostly.
With the application of new shipbuilding technologies, ships are getting bigger than before. The diameter of stern tubes of very large oil tankers, bulk carriers and large container ships is relatively large, some are about 1000mm; the stern tubes are also longer, generally about 5000- 10500mm. On site line boring in the above way will produce the following adverse effects: 1. The stern tube is longer, the boring bar is longer and heavier, and the deflection produced is also larger, which affects the quality of the boring. 2. It is necessary to manufacture longer boring bars, which requires huge investment.
Stern column shaft shell boring procedure and requirements
Special tool inspection: On-site inspection of supporting bearing clearance, smoothness of boring row, flexible feeding of gearbox, and matching of a certain number of bearings, tool holders and tools.
Drawing: Familiar with the design drawing and the technical layout drawing of the support bearing and measure the actual position of the boring row.
Handling of the boring row: remove the boring row from the vertical spreader and place it on a special V-shaped frame to transport to the use site, and irregular handling is strictly prohibited.
Installation of the boring bar: wrap the inner hole of the stern column shaft shell (lower piece) with a pure aluminum plate or thick rubber skin with a thickness of more than 3 mm, lift it in a V shape with two gourds, and string it in along the forward direction.
Supporting bearing positioning: After the boring row is inserted into the shaft hole of the stern column, it is lifted with a V-shaped pulley frame, and the straight grain is aligned with the multi-angle calibration with a marking plate or a special inner card to meet the requirements.
Fixing of the bearing frame: install the support frame according to the requirements of the process drawing. When the seat plate, stay plate and hull or compartment are welded, the fastening screws of the bearing shell must be completely loosened.
Alignment of the boring row: After the supporting bearing frame is welded and cooled, the double-line alignment can be adjusted with screws, and the center position can be adjusted until it meets the requirements.
Whole system inspection: After the calibration work is completed, the power system can be connected, and the lubricating oil can be added to carry out the test run of the motor car and check: (1) vibration at low speed; (2) whether the feeding position meets the requirements; (3) After running for a few minutes, whether there is any obvious reflection of the bearing temperature of each gear, and the shaft temperature is not higher than 45°
Feed: Feed a small amount after manually leading the tool to ensure that there is no obstacle before feeding according to rough boring.
Rough boring: The boring row runs stably and the rolling cutter can be fed according to the maximum cutting amount without serious problems.
Re-inspection: When the rough machined surface accounts for 90% of the total area of the shaft shell, a re-inspection must be carried out. Check the boring row to find the center line to measure the inner hole size, and check the size of the stern tube blank to control the machining allowance.
Fine boring: After the rough boring is checked correctly, it will enter the fine boring. It is required that the boring row runs stably, without vibration, without rolling cutter, and the smoothness meets the requirements. Fine boring work should be carried out at night or in rainy days to prevent hull deformation.
Scraping plane: The scraping of the plane can only be carried out after the inner hole has been processed and passed the inspection (because the inspection circle line has been polished after processing).
Sample bar: After boring and passing inspection, technicians, inspectors, and craftsmen will draw tail pipe processing drawings.
Stern column shaft shell boring technical requirements
1. The deviation between the boring center and the original positioning center line of the shaft hole should be less than 0.10mm, and the shaft shell hole of the stern post shaft shell should be
And the center of the bulkhead hole should be coaxial, and the misalignment should be within 0.10 mm.
2. The front, middle and rear bearing holes of the shaft system should be coaxial, and the misalignment should not be greater than 0.20 mm.
3. After the hole end surface is processed, it should be perpendicular to the axis line, and its non-perpendicularity should not be greater than 0.20 mm.
4. Requirements for the smoothness of the processed surface, the mating surface is 6.3, and the non-matching surface is 25.
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