Pre-construction preparation → Remove bolts connecting the crossbeam and upper frame → Remove crossbeam cap → Remove crossbeam bushing → Remove crossbeam → Hoist out the main shaft → Cleaning → Remove old eccentric bushing → Install new eccentric bushing → Check and adjust clearance between eccentric bushing and main shaft → Install main shaft → Install crossbeam → Tighten bolts connecting crossbeam and upper frame → Install crossbeam bushing → Install crossbeam cap → Test run → Re-tighten bolts connecting crossbeam and upper frame
1.1.1 Check the eccentric bushing, transport the verified eccentric bushing to the -920m crushing chamber.
1.1.2 Prepare dry ice required for the removal and installation process.
1.1.3 Fabricate required processing parts for the replacement process and transport them to the -920m crushing chamber.
1.2.1 Prepare all necessary lifting wire ropes, shackles, lifting lugs, daily tools for fitters, and special tools.
1.2.2 Prepare 600---650mm inside micrometers and outside micrometers.
1.3.1 Inspect and confirm facilities such as the -920m 50T crane, lifting eyes, shackles, chain hoists, etc.
Record the original position of the main shaft.
2.1 Remove bolts connecting the crossbeam and upper frame while cleaning fine ore from the discharge opening.
3.1 Clean the lifting hole of the crossbeam cap, thread a 3-part wire through the lifting hole, use the 50T crane to hoist the crossbeam cap out and place it in an open area.
4.1 Clean the top of the cover plate to prevent dirt from entering the crossbeam. Remove the hex socket screws inside the cover plate and take off the cover plate.
4.2 Remove the crossbeam bushing bolts and washers, screw the jacking bolts into the tapered holes on the crossbeam bushing to push out the bushing.
4.3 Thread a 3-part wire through the 0.5" lifting lug, hoist the crossbeam bushing out and place it in an open area.
5.1 Use one Φ32mm 12m long wire rope, loop it 4 times and connect it to the 50T crane. Use the 50T crane to hoist the crossbeam out and place it in an open area.
6.1 Connect the 30T shackle with pin to the main shaft lifting hole. Use one 4m long 6-part wire, wrap it 7 times around the 50T crane hook and connect it to the shackle. Slowly raise the crane to hoist the main shaft out and place it into the main shaft hole in front of the rest room.
7.1 Clean residual oil and debris from inside the eccentric bushing.
8.1.1 Remove dust ring screws, take off the dust ring and gasket.
8.2.1 Remove flat head screws of the oil slinger, remove the upper counterweight oil slinger ring.
8.2.2 Remove four hex socket cap screws, install three 1" lifting lugs into the lifting holes on top of the counterweight assembly, then hoist it away from the eccentric shaft.
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8.3.1 Place the fabricated wooden platform inside the eccentric bushing, lay cotton waste or cotton on the platform until it extends beyond the bottom of the eccentric bushing.
8.3.2 Lay a layer of plastic sheet on the inner surface of the eccentric bushing.
8.3.3 Install the 0.5" lifting lug into the lifting hole of the eccentric bushing.
8.3.4 Pour fine dry ice into the eccentric bushing, cover with the wooden lid, until frost forms on the outer surface of the eccentric bushing. This usually takes 2 hours.
8.3.5 Connect a 3-part wire to the lifting lug, use the crane to hoist out the eccentric bushing.
8.3.6 Remove the eccentric bushing key.
9.1 Install the key into the keyway of the eccentric bushing, install the 0.5" lifting lug into the lifting hole of the eccentric bushing.
9.2 Cool the eccentric bushing with the key using fine dry ice until frost forms on the outer surface of the eccentric bushing. This usually takes 2 hours.
9.3 Use a 3-part wire to hoist the eccentric bushing horizontally, align the position, and push the sleeve into the eccentric shaft hole.
9.4 Press the eccentric bushing into the eccentric shaft.
9.5.1 Place the upper counterweight assembly onto the top of the eccentric shaft, secure it to the eccentric shaft with bolts.
9.5.2 Install the upper counterweight oil slinger ring.
9.6.1 Use locating dowel pins to assemble the dust ring and gasket onto the upper frame, tighten the dust ring screws.
10.1.1 Before installing the main shaft into the crusher, remove all bronze color penetration on the lower journal.
10.1.2 First use 180 grit coarse sandpaper, finally use 240 grit coarse sandpaper for polishing.
11.1 Connect the 30T shackle with pin to the main shaft lifting hole. Use one 4m long 6-part wire, wrap it 7 times around the 50T crane hook and connect it to the shackle. Slowly operate the crane to hoist the main shaft out of the main shaft hole in front of the rest room.
11.2 Hoist the main shaft into the crushing cavity, adjust the crane position so the clearance between the main shaft lower journal and the eccentric bushing is roughly equal on left and right (arrange personnel to observe from the bin). Slowly lower the main shaft until it is fully in place.
12.1 Check the tapered mating surfaces between the crossbeam and upper frame, remove burrs, scratches, rust, and other debris. Apply low viscosity oil on the horizontal mating surface of the crossbeam.
12.2 Use one Φ32mm 12m long wire rope, loop it 4 times and connect it to the 50T crane. Use the 50T crane to hoist the crossbeam above the crushing cavity, slowly lower the crossbeam, adjust the crane position to align the crossbeam holes with the connecting bolts, lower the crane until the crossbeam fully rests on the upper frame.
13.1 Tighten 2 bolts 180 degrees apart, ensuring the gap between the upper frame and crossbeam is even. Then, install 2 more bolts diagonally, 90 degrees from the first two, also maintaining the same gap. The tightness of other bolts should be the same as the first four. Tighten the bolts sequentially one by one until a 0.1mm feeler gauge cannot be inserted between the flanges tightened by the bolts at any point on the circumference.
14.1 Install the main shaft oil scraper ring into the crossbeam hub.
14.2 Install the crossbeam bushing and oil seal into the crossbeam hub, tighten the bushing bolts, install the cover plate, tighten the cover plate screws.
16.1 Raise the main shaft to its pre-maintenance position.
16.2 During trial operation, if the main shaft rotates clockwise at no more than 12 rpm, the crusher can run idle for several hours. If it exceeds 12 rpm, lower one or two tires tied with a rope into the crushing cavity. Let the crusher run idle for several hours until the speed returns to normal.
16.3 Test with load and observe if the crusher operates normally.
17.1 After the crusher has run for several hours, the bolts connecting the upper frame and crossbeam may loosen. Therefore, after running for a period, check and tighten the bolts.
1. All processed parts must be manufactured according to drawings and technical requirements.
2. All original records must be accurate and complete.
3. Cranes and lifting tools must be carefully inspected.
4. The clearance between the main shaft and eccentric bushing must be polished to meet requirements.
5. Bolts connecting the upper frame and crossbeam must be tightened securely as required.
6. Cooling the eccentric bushing with dry ice must be strictly executed as required; installation can only proceed after meeting the installation standard.
Firmly establish the mindset of "Safety first, prevention为主", overcome negligence, reckless risk, and empirical violations. Strictly adhere to the "Do not harm yourself, do not harm others, do not be harmed by others" requirement, enforce strict management, implement various rules and regulations, eliminate illegal operations and illegal commands. Requirements:
1. During the construction of this project, obey unified dispatch and command, do not disrupt this plan擅自.
2. Wear safety harness for high altitude operations are strictly prohibited, and cross operations are strictly prohibited
3. Strictly comply with the "Metallurgical Underground Mine Safety Regulations" during construction, strictly wear labor protection supplies, and do not perform any illegal operations.
4. During construction, the construction quality of important steps must be confirmed by designated personnel.
5. The construction charge is also the primary safety responsibility person and primary quality responsibility person. The lead repair person is also the on-site safety responsibility person.
6. All construction personnel (including auxiliary support personnel) are not allowed to be late, leave early, or leave their post.
7. Before construction, all lifting tools and equipment must undergo a comprehensive safety inspection, especially the 50T crane.
8. The construction charge must comprehensively inspect the job environment at the construction site to ensure it meets safety requirements,同时 take safety precautions, and communicate safety requirements and precautions to construction personnel.
9. After electrical circuits and equipment are disconnected, a "Someone operating, do not close switch" warning sign must be hung, monitored by a designated person.
10. All personnel participating in the construction are not allowed to casual rest. Rest must be approved by the construction charge.
11. When lifting heavy objects, first check if the bundling is secure. Provide padding where ropes pass over sharp edges. Hoisting can only proceed after inspection confirms it is safe and reliable.
12. At every stage of construction, the work site must be cleaned promptly.
13. Organize construction personnel to familiarize themselves with the plan, conduct technical briefings. They must be familiar with the process and technical requirements.
14. When handling dry ice, take protective measures to prevent frostbite.
15. When operating oxy-acetylene welding, pay attention to fire prevention measures.
16. The construction of this project must strictly follow the approved plan.
6*37 Φ32mm wire rope total breaking force: 66650 Kg
Crossbeam assembly weight: 20500 Kg
Safety factor for 6*37 Φ32mm wire rope looped 4 times n=66650*4/20500=13
Meets requirement
6-part wire total breaking force: 15900 Kg
Main shaft assembly weight: 23130 Kg
Safety factor for 6-part wire looped 7 times n=15900*14/23130=9.6
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