Core Purpose Description
This document focuses on the drum shaft assembly parts of BOMCO drawworks series, including JC-90, JC-70, JC-50, JC-40 and their DB/D variants. These parts are exclusively compatible with the aforementioned BOMCO drawworks models, tailored for oilfield drilling enterprises, professional drilling rig maintenance service providers, and oilfield equipment rental companies. They address pain points such as drum jamming, shaft deformation, bearing damage, and hydraulic control failure caused by high load, strong vibration, and harsh working conditions (dust, humidity, alternating temperature) during drilling operations. All parts comply with API Spec 7K "Drilling and Well Servicing Equipment" and GB/T 23505-2009 "Drilling Rig Drawworks" standards, ensuring the stable transmission and reliable braking of the drawworks, and providing authoritative technical support for the safe and efficient operation of the equipment.
1. Core Load-Bearing Components
This category includes rolling drum unit assembly, shaft, bearings, and partition sleeves, which are the core force-bearing parts of the drum shaft assembly, responsible for load-bearing and power transmission. They solve pain points of structural deformation, bearing wear, and transmission failure caused by long-term high-load operation. Suitable for the maintenance and replacement of core components of BOMCO multi-model drawworks drum shaft assemblies.
No. | Product Name | Model/ Drawing No. | Material | Main Wear Causes | Damage Prevention Precautions |
1 | Rolling Drum Unit Assembly | AF000003-1000 | Drum Body: Q355B carbon steel (integral welding + stress relief heat treatment); Liner: 40Cr alloy steel (surface quenching); Connecting Parts: 42CrMo alloy steel | 1. Liner wear and grooving caused by long-term friction with the drilling rope; 2. Welding seam fatigue cracking caused by alternating load and vibration | 1. Regularly inspect the liner wear (allowable wear ≤ 5mm), and replace or weld repair if excessive; 2. Conduct non-destructive testing (NDT) on welding seams every 6 months, and repair cracks in time |
2 | Shaft | AF700B03-0209 | 42CrNiMo alloy steel (integral forging + quenched and tempered treatment); Surface: precision grinding + chrome plating | 1. Shaft neck wear and pitting caused by insufficient lubrication and bearing friction; 2. Shaft bending deformation caused by uneven load and impact | 1. Ensure sufficient lubrication of the bearing, use high-quality lubricating grease (NLGI 2), and check the oil level regularly; 2. Check the shaft runout every 3 months (allowable runout ≤ 0.03mm), and correct or replace if deformed |
3 | Bearing | 23148CA/C3W33 (Part No.: 480102002814800000) | Inner/Outer Ring & Rolling Elements: GCr15 bearing steel (quenched and tempered); Cage: Brass; Sealing Ring: Nitrile rubber | 1. Rolling element wear and cage damage caused by dust intrusion and poor lubrication; 2. Bearing overheating and burning caused by misalignment and high-load operation | 1. Install a dust cover at the bearing end, replace the lubricating grease every 500 operating hours; 2. Align the shaft and bearing seat with a laser alignment instrument (alignment accuracy ≤ 0.01mm), and monitor the bearing temperature (allowable temperature ≤ 75℃) |
4 | Partition Sleeves (I/II/III) | Partition sleeve I (AF700303-0207), Partition sleeve Ⅱ (AF700303-0203), Partition sleeve Ⅲ (AF700303-0211) | 45# carbon steel (quenched and tempered); Surface: precision machining | 1. End face wear caused by long-term contact and friction with the bearing; 2. Deformation caused by assembly interference and thermal expansion | 1. Apply a thin layer of molybdenum disulfide lubricant on the end face during assembly; 2. Control the assembly interference (0.015-0.03mm), and check the sleeve fit status regularly |
2. Auxiliary Protection & Control Components
This category includes bearing caps, pressure plates, water pipe assemblies, and hydrosphere control units, which provide protection, sealing, and cooling/control functions for the drum shaft assembly. They solve pain points of dust intrusion, oil leakage, overheating, and control failure. Suitable for the maintenance of auxiliary systems of BOMCO multi-model drawworks drum shaft assemblies.
No. | Product Name | Model/ Drawing No. | Material | Main Wear Causes | Damage Prevention Precautions |
1 | Bearing Caps (Left/Right) | Left bearing cap (AF700303-0206), Right bearing cap (AF700303-0213) | HT250 gray cast iron (normalized); Sealing Groove: Precision machining; Fastening Holes: Thread rolling | 1. Sealing failure caused by aging of the sealing ring and wear of the sealing groove; 2. Cap deformation caused by uneven fastening force | 1. Replace the sealing ring every 12 months, check the sealing groove wear (allowable wear ≤ 0.1mm); 2. Tighten the fixing bolts evenly with a torque wrench, and apply thread lock glue |
2 | Pressure Plates | AF700305-0301, AF7003030212 | Q235B carbon steel (galvanizing); Surface: Flat grinding | 1. Surface wear caused by long-term friction with the connected component; 2. Corrosion caused by humid environment and oil contamination | 1. Apply anti-wear gasket between the pressure plate and the connected component; 2. Regularly clean the surface and repaint anti-corrosion paint every 12 months |
3 | Water Pipe Assemblies | AF700303-020100, AF700303-0219 | Pipe Body: Red copper (high thermal conductivity); Joints: 304 stainless steel; Seal Rings: Nitrile rubber | 1. Pipe deformation and cracking caused by collision and vibration; 2. Joint leakage caused by seal ring aging and water pressure fluctuation | 1. Fix the water pipe with anti-vibration pipe clips, avoid collision during operation; 2. Replace the seal ring every 6 months, and check the water pressure (maintain within the rated range of 0.3-0.5MPa) |
4 | Hydrosphere Control Units & Water-Am Instrument | Hydrosphere contrl uts (AF000001-1300), Water-am instrument (AF0000010600) | Hydrosphere Control Units: Aluminum alloy (anodized) + 304 stainless steel components; Water-Am Instrument: Shell (304 stainless steel) + Glass (pressure-resistant) | 1. Control valve jamming caused by water quality impurities; 2. Instrument glass breakage caused by vibration and impact | 1. Install a filter at the water inlet to ensure water quality (particle size ≤ 0.1mm); 2. Fix the instrument with a shock-absorbing bracket, and install a protective cover |
5 | Oil Seal | PD260X300X20 (Part No.: 530301142603002000) | Sealing Lip: Nitrile rubber (oil-resistant); Skeleton: 08F carbon steel; Spring: 65Mn steel; Comply with HG4-692 standard | 1. Sealing lip wear caused by long-term friction with the rotating shaft; 2. Skeleton corrosion caused by humid environment and oil erosion | 1. Check the shaft surface smoothness before installation (Ra ≤ 0.8μm), avoid sharp edges; 2. Apply a thin layer of lubricating grease on the sealing lip, and replace every 12 months |
6 | Oil Cup | M10X1 (Part No.: 61302011152101000) | Body: 304 stainless steel; Cover: Engineering plastic; Seal Ring: Nitrile rubber | 1. Blockage caused by dust and lubricating grease solidification; 2. Seal leakage caused by cover loosening | 1. Clean the oil cup mouth every 15 days, and add lubricating grease regularly; 2. Tighten the cover after adding grease, and check the seal status regularly |
3. Connecting & Fastening Components
This category includes bolts, nuts, spring washers, keys, and iron wires, which provide reliable connection and fastening functions for the drum shaft assembly. They solve pain points of component loosening, displacement, and transmission failure caused by strong vibration and alternating load. Suitable for the overall maintenance of BOMCO multi-model drawworks drum shaft assemblies.
No. | Product Name | Model/ Part No. | Material | Main Wear Causes | Damage Prevention Precautions |
1 | Bolts | M36×120 (AF700303-0215), M36×130 (AF700303-0216), M30×330 (AF700303-021003), M20X4 (420201040720043000), M20X50 (420201011120050000), M8X20 (420200140708020000), M20X30 (420201041120030000) | M36/M30: 42CrMo alloy steel (heat treatment); M20: 40Cr alloy steel (heat treatment); M8: 35# carbon steel (heat treatment); Thread: Precision rolling | 1. Thread wear caused by repeated disassembly and assembly; 2. Bolt fatigue and fracture caused by long-term strong vibration | 1. Apply anti-rust lubricating oil on the thread during installation, and use a torque wrench to control the tightening force (M36: 280-300N·m; M20: 60-65N·m); 2. Check the bolt tightness every 7 days, and replace bolts with signs of fatigue |
2 | Nuts | M36 (420402016360400000), M30 (420402012300200000) | 45# carbon steel (heat treatment); Surface: Galvanizing; Thread: Precision rolling | 1. Thread loosening caused by strong vibration; 2. Corrosion caused by humid environment and oil contamination | 1. Use spring washers and Loctite 243 lock glue to enhance anti-loosening performance; 2. Paint the nut surface with anti-corrosion paint, and avoid direct contact with drilling fluid |
3 | Spring Washers | Spring washer (420803016201600000), Spring washer 36 (420503016361600000), Spring washer 8 (420503016081600000) | 65Mn steel (heat treatment); Surface: Phosphating | 1. Fatigue and loss of elasticity caused by long-term compression; 2. Corrosion caused by humid environment and oil contamination | 1. Replace the spring washer every 6 months, and check the elasticity regularly; 2. Store spare washers in a dry environment, and apply anti-rust oil after disassembly |
4 | Keys | B50X28X2B2 (AF700303-0202), B56X56X280 (AF700303-0208) | 45# carbon steel (quenched and tempered); Surface: Precision grinding | 1. Wear of the key and keyway caused by long-term torque transmission; 2. Key deformation caused by overload torque | 1. Apply lubricating grease on the key and keyway during assembly; 2. Check the key and keyway wear every 3 months (allowable wear ≤ 0.1mm), and replace if excessive |
5 | Iron Wire | Φ1.5 (40101010150600000) | Low-carbon steel (galvanizing) | 1. Rust and breakage caused by humid environment; 2. Fatigue fracture caused by repeated bending | 1. Avoid repeated bending during use, and cut to the appropriate length; 2. Store in a dry environment, and replace rusted iron wire in time |
6 | Adjust Shim Unit Ⅱ | AF700303-0203 | Q235B carbon steel (galvanizing); Thickness: Precision stamping | 1. Deformation caused by uneven pressure; 2. Corrosion caused by humid environment | 1. Ensure uniform pressure distribution during assembly, and select shims of appropriate thickness; 2. Regularly check the shim flatness, and replace if deformed or corroded |
Field Fault Maintenance Case
Case: BOMCO JC-70DB Drawworks Drum Shaft Bearing Burning Failure - During on-site drilling operation, the drawworks drum rotated with abnormal noise, and the right bearing end temperature rapidly rose to 105℃, leading to forced shutdown. Inspection found that the 23148CA/C3W33 bearing was severely burned, the oil seal was aged and cracked, and a large amount of dust and metal particles were mixed in the lubricating grease. Root cause: The oil seal failed to prevent dust intrusion, resulting in contamination of the lubricating grease; the lubricating grease was not replaced in time, leading to poor lubrication and bearing overheating.
Complete Solution: 1. Safety Preparation Stage: a) Immediately cut off the power supply of the drawworks and lock the power switch, hang a "No Operation Under Maintenance" warning sign around the maintenance area to avoid misoperation; b) Wait for the right bearing end to cool down naturally to below 40℃ (prohibit forced cooling with water to prevent thermal deformation of the shaft and bearing seat); c) Maintenance personnel wear professional protective equipment (high-temperature resistant gloves, goggles, anti-skid safety shoes) to ensure operation safety; d) Prepare special tools (bearing puller, torque wrench, laser alignment instrument), cleaning materials (anhydrous ethanol, industrial degreaser), and replacement parts (new 23148CA/C3W33 bearing, PD260X300X20 oil seal, high-temperature resistant lubricating grease NLGI 2, additional dust cover matching the bearing cap) in place. 2. Disassembly of Faulty Components: a) Remove the right bearing cap fastening bolts in a symmetrical and uniform manner using a torque wrench, take down the right bearing cap, and check the sealing groove wear (no obvious wear found in this case); b) Use a bearing puller to slowly pull out the severely burned 23148CA/C3W33 bearing from the drum shaft neck, and pay attention to protecting the shaft neck surface during disassembly to avoid scratches; c) Take out the aged and cracked PD260X300X20 oil seal from the bearing cap sealing groove, and clean the residual sealant and grease in the groove; d) Disconnect the lubricating oil cup connected to the bearing chamber, and plug the oil cup interface with a clean rubber plug to prevent impurities from entering. 3. Comprehensive Cleaning Treatment: a) Use industrial degreaser to thoroughly clean the drum shaft neck, bearing seat inner cavity, and bearing cap, focusing on removing the mixed dust, metal particles, and carbonized grease residues; b) Use anhydrous ethanol to secondary clean the shaft neck and bearing seat, and dry them with clean compressed air (air pressure ≤ 0.4MPa to avoid damaging the shaft surface); c) Check the shaft neck surface with a surface roughness meter, ensuring the roughness Ra ≤ 0.8μm; if there are slight scratches, polish them with fine sandpaper (400#) until smooth; d) Clean the oil cup and its pipeline, and confirm that the oil passage is unblocked. 4. Component Replacement & Assembly: a) Oil Seal Installation: Apply a thin layer of NLGI 2 lubricating grease on the sealing lip of the new PD260X300X20 oil seal, use a special press tool to press the oil seal into the bearing cap sealing groove evenly (avoid knocking to prevent oil seal deformation), and ensure the oil seal is installed in place without tilting; b) Bearing Installation: i) Apply a thin layer of lubricating grease on the inner ring of the new 23148CA/C3W33 bearing and the shaft neck installation surface; ii) Heat the bearing to 80-90℃ in an oil bath (strictly control the temperature, no exceeding 100℃ to avoid damaging the bearing material structure); iii) Use a special sleeve to quickly and evenly press the heated bearing onto the shaft neck, and check that the bearing fits closely with the shaft neck without looseness after cooling; c) Additional Dust Cover Installation: Install a matching additional dust cover on the outer side of the bearing cap, align the mounting holes with the bearing cap holes, and fix them with stainless steel bolts (tightening torque: 15-20N·m) to enhance dustproof effect; d) Bearing Cap Reassembly: Apply a thin layer of thread lock glue on the bearing cap fastening bolts, install the bolts symmetrically, and tighten them with a torque wrench according to the specified torque (25-30N·m) to ensure uniform stress on the bearing cap; e) Oil Cup Reinstallation: Reconnect the cleaned oil cup to the bearing chamber interface, and tighten it to ensure no oil leakage. 5. Lubrication Filling & System Debugging: a) Open the oil cup cover, fill the bearing chamber with high-temperature resistant lubricating grease (NLGI 2) until the grease overflows slightly from the bearing gap (filling amount is 1/2-2/3 of the bearing internal space), and then tighten the oil cup cover; b) Restore the power supply of the drawworks, start the drawworks for no-load operation, and monitor the right bearing end temperature in real time with an infrared thermometer: within 30 minutes of operation, the temperature should rise steadily and not exceed 70℃, and there should be no abnormal noise; c) Conduct laser alignment detection on the drum shaft and bearing seat, adjust the shim thickness if necessary, ensuring the alignment accuracy ≤ 0.01mm; d) Carry out load test: gradually apply 50%, 80%, and 100% of the rated load to the drawworks, and each load level operates for 1 hour. During the period, monitor the bearing temperature (stable at 65-70℃) and the operation status of the drum, confirming no abnormal vibration or noise. 6. Post-Maintenance Inspection: After the drawworks operates stably for 4 hours, stop the machine to recheck: a) Check the bearing end, bearing cap, and oil cup for oil leakage; b) Check the tightness of the additional dust cover bolts; c) Extract a small amount of lubricating grease from the bearing chamber for inspection, confirming no dust or metal particles. 7. Long-Term Preventive Maintenance Measures: a) Formulate a fixed maintenance plan: Clearly stipulate that the PD260X300X20 oil seal is replaced every 12 months, and the 23148CA/C3W33 bearing lubricating grease (NLGI 2) is replaced every 500 operating hours; b) Daily inspection system: Add the bearing end temperature (daily 3 times, record data) and oil seal integrity (daily 1 time) to the drawworks daily inspection list, and immediately stop the machine for inspection if the bearing temperature exceeds 75℃ or the oil seal is found to be damaged; c) Regular cleaning: Clean the additional dust cover and oil cup mouth every 15 days to prevent dust accumulation and blockage; d) Personnel training: Train on-site operators and maintenance personnel on the judgment methods of bearing abnormal temperature and oil seal aging, and the standard operation process of lubricating grease replacement, ensuring that potential faults are found and handled in time.
After maintenance, the drawworks operated normally, and the bearing temperature remained within 70℃.
Procurement Guide & Call to Action
All drum shaft assembly parts listed in this document are exclusively compatible with BOMCO drawworks series (JC-90, JC-70, JC-50, JC-40 and their DB/D variants), complying with API Spec 7K and GB/T 23505-2009 standards, with genuine quality and complete certification. When purchasing, please confirm the product's model, drawing number, part number, and the specific drawworks model to ensure accurate matching. Our professional technical team provides one-on-one technical consultation services, covering product selection, on-site installation guidance, fault diagnosis, and maintenance training. For detailed product parameters, material performance reports, API certification documents, and procurement quotes, please contact us at your convenience. We are committed to providing you with high-quality, genuine BOMCO drawworks drum shaft assembly parts and professional after-sales support, ensuring the efficient, stable, and safe operation of your drilling equipment.
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