Drilling Rig Auxiliary Sheave Assemblies

1

Sheave frame

101.51.71.00

Q355B low-alloy high-strength steel (integrally cast, normalized heat treatment)

1. Fatigue cracking due to long-term alternating load stress concentration; 2. Corrosion pitting from prolonged exposure to water-based drilling fluid; 3. Impact damage from accidental collision with drilling tools during operation.

1. Conduct magnetic particle testing (MPT) every 3 months to detect hidden cracks; 2. Apply epoxy anti-corrosion coating to the surface annually, focusing on weld joints and stress concentration areas; 3. Strictly adhere to the rated load limit of the auxiliary hoisting system to avoid overloading.

2

Pin plate δ8

101.51.70.01

Q235A carbon steel plate (thickness 8mm, hot-rolled, surface phosphatized)

1. Shear deformation caused by uneven load distribution during assembly; 2. Wear at pin holes due to insufficient lubrication and relative rotation with pin shafts; 3. Edge curling from improper installation tools (e.g., prying with pliers).

1. Verify the coaxiality of pin holes (tolerance ≤0.05mm) before assembly; 2. Apply molybdenum disulfide lubricant to pin hole inner walls to reduce frictional wear; 3. Replace immediately if pin hole wear exceeds 0.5mm or edge deformation is observed.

3

Auxiliary sheave shaft

101.51.70.02

40Cr alloy steel (quenched and tempered, hardness HRC 28-32, journal surface ground)

1. Bending deformation due to excessive radial load from misaligned sheaves; 2. Journal wear caused by bearing lubrication failure; 3. Fatigue failure at shaft steps due to stress concentration.

1. Check radial runout of the shaft monthly (allowable error ≤0.03mm); 2. Fill bearings with high-temperature lithium-based grease (operating temperature -20℃ to 120℃) every 200 working hours; 3. Install a shaft sleeve during assembly to avoid direct impact on the journal.

4

Sheave φ400

101.51.70.03

ZG310-570 cast steel (sheave groove surface carburized, hardness HRC 55-60, precision ground)

1. Uneven groove wear due to wire rope misalignment; 2. Pitting corrosion on groove surfaces from drilling fluid and moisture; 3. Thermal fatigue cracking from long-term high-speed friction with wire ropes.

1. Align the sheave to ensure the wire rope is centered in the groove (offset tolerance ≤2mm); 2. Install a dust-proof and water-proof cover to prevent contamination of the groove surface; 3. Measure groove wear depth quarterly—replace or regrind if wear exceeds 3mm (10% of groove depth).

5

Circlip

101.51.70.04

65Mn spring steel (heat-treated, hardness HRC 42-48, surface passivated)

1. Elastic fatigue and deformation from long-term radial compression; 2. Corrosion-induced brittleness from moisture intrusion; 3. Ear damage during installation/disassembly with improper tools.

1. Use dedicated circlip pliers for installation and removal to avoid damaging the ears; 2. Inspect elasticity regularly—replace if the circlip cannot fully seat in the groove; 3. Store in a dry, moisture-free environment to prevent corrosion.

6

Seal disc

101.51.70.05

NBR nitrile rubber (Shore hardness 70±5) with steel skeleton (Q235A)

1. Aging and cracking due to high temperature (exceeding 80℃) and oil contamination; 2. Scratches on the sealing lip from foreign particles; 3. Deformation from excessive assembly pressure.

1. Avoid contact with high-temperature hydraulic oil and strong corrosive media; 2. Clean the sealing surface and mating parts thoroughly before assembly; 3. Control assembly pressure within 0.3-0.5MPa using a pressure-controlled tool.

7

Inner spacer

101.51.70.06

20# carbon steel (precision machined, surface roughness Ra 1.6μm)

1. Axial wear from frictional contact with adjacent components; 2. Deformation due to uneven axial preload; 3. Corrosion from lubrication deficiency.

1. Apply a thin layer of anti-wear lubricating oil to both end faces before assembly; 2. Check flatness (tolerance ≤0.02mm) and dimensional accuracy before use; 3. Ensure axial clearance between components is maintained at 0.1-0.2mm.

8

Retainer 42

101.51.70.07

Q235A carbon steel (stamped and formed, surface hot-dip galvanized)

1. Shear failure due to excessive axial load; 2. Galvanized layer peeling and subsequent corrosion; 3. Deformation from improper storage or transportation.

1. Confirm the retainer’s rated axial load matches the application requirements; 2. Avoid stacking heavy objects on the retainer during storage; 3. Touch up peeled galvanized areas with zinc-rich paint promptly.

9

Pin shaft

101.51.70.08

45# carbon steel (quenched and tempered, hardness HRC 25-30)

1. Surface wear from long-term relative rotation with bushings/retainers; 2. Bending deformation from lateral impact loads; 3. Fatigue cracking at the shaft shoulder due to stress concentration.

1. Lubricate the shaft surface with lithium-based grease every 150 working hours; 2. Inspect straightness monthly (allowable error ≤0.03mm); 3. Use a plastic or copper sleeve when driving the pin shaft to avoid surface damage.

10

Safety chain

101.51.70.09

20Mn2 alloy steel (welded chain links, surface galvanized, tensile strength ≥800MPa)

1. Fatigue wear of chain links from repeated tension cycles; 2. Corrosion-induced weakening of weld joints; 3. Fracture from overloading or sudden impact.

1. Never exceed the chain’s rated load (refer to equipment manual); 2. Inspect weld joints for cracks and chain links for wear (allowable wear ≤2mm) monthly; 3. Clean the chain with diesel oil and reapply anti-rust oil quarterly.

11

Washer 42

101.51.70.10

Q235A carbon steel (stamped, surface phosphatized)

1. Deformation from excessive bolt tightening torque; 2. Abrasion of contact surfaces due to equipment vibration; 3. Corrosion from moisture ingress.

1. Use a torque wrench to apply the specified tightening torque (consistent with M42 bolt requirements); 2. Replace washers if they show signs of warping or uneven contact; 3. Ensure the washer is fully seated between the nut and the mating surface.

12

Slotted nut M42

101.51.70.11

45# carbon steel (heat-treated, internal thread precision class 6H)

1. Thread wear from repeated assembly/disassembly; 2. Slot damage from improper cotter pin installation; 3. Thread seizure due to corrosion or lack of lubrication.

1. Apply anti-seize compound to the threads before assembly; 2. Use a slotted nut wrench to avoid damaging the slot edges; 3. Ensure the cotter pin is fully inserted and bent to secure the nut—do not reuse cotter pins.

13

Cotter pin 8X80

GB91-87(8X80)

65Mn spring steel (heat-treated, surface passivated)

1. Fatigue fracture from repeated vibration; 2. Corrosion-induced brittleness; 3. Damage during installation (e.g., over-bending).

1. Select cotter pins that match the nut slot size (do not use oversized/undersized pins); 2. Bend the pin ends at 90° to ensure secure retention—avoid over-bending to prevent material fatigue; 3. Replace cotter pins whenever they are removed during maintenance.

14

Bolt M12X20

GB32.1-86(M12X20)

4.8-grade carbon steel (Q235A), surface galvanized

1. Thread stripping due to over-tightening; 2. Corrosion of the galvanized layer leading to rust; 3. Fatigue failure from continuous vibration.

1. Torque to 35-40 N·m using a calibrated torque wrench; 2. Inspect for rust or galvanized layer peeling monthly; 3. Use lock washers (if applicable) to prevent loosening from vibration.

15

Iron wire φ2

GB343-82(φ2)

Low-carbon steel (08F), annealed for ductility

1. Fatigue breakage from repeated bending; 2. Corrosion from exposure to drilling fluid; 3. Tensile failure from overloading.

1. Use the wire only for securing small components (do not use as a load-bearing member); 2. Avoid sharp bends when installing to prevent material damage; 3. Replace with new wire during each maintenance cycle.

16

Bearing φ80Xφ170X39

GB283-64(42316)

High-carbon chromium bearing steel (GCr15), cage made of 20# carbon steel

1. Seizure due to contamination (drilling fluid/dust) or insufficient lubrication; 2. Rolling element fatigue from long-term heavy loads; 3. Inner/outer ring wear due to misalignment.

1. Keep the bearing clean during storage and assembly—avoid direct contact with contaminated surfaces; 2. Fill with high-temperature bearing grease (70% of bearing internal volume) before installation; 3. Check bearing runout (allowable error ≤0.02mm) and temperature (normal operating temp <70℃) during operation.

1

Sheave frame

101.51.81.00

Q355B low-alloy high-strength steel (integrally cast, quenched and tempered)

1. Fatigue cracking at weld joints due to high alternating loads; 2. Corrosion from saltwater or chemical drilling fluid (in coastal/marine drilling); 3. Impact damage from heavy drilling tool collisions.

1. Conduct ultrasonic testing (UT) of weld joints every 6 months to detect internal defects; 2. Use marine-grade anti-corrosion coating for coastal/marine applications; 3. Install protective guards around the frame to prevent tool collisions.

2

Pin plate δ8

101.51.70.01

Q235A carbon steel plate (thickness 8mm, hot-rolled, surface phosphatized)

1. Shear deformation caused by uneven load distribution; 2. Pin hole wear from relative rotation with high-load pin shafts; 3. Edge damage from improper installation.

1. Ensure uniform load distribution by verifying component alignment before assembly; 2. Apply wear-resistant coating to pin hole inner surfaces for high-load applications; 3. Use precision alignment tools during installation to avoid edge damage.

3

Shaft

101.51.70.021

40CrNiMo alloy steel (quenched and tempered, hardness HRC 30-35, journal nitrided)

1. Bending deformation from high radial loads in deep drilling operations; 2. Journal wear due to bearing failure; 3. Nitride layer peeling from improper lubrication.

1. Monitor radial load during operation—avoid exceeding the shaft’s rated capacity; 2. Use high-pressure lubrication systems for bearings to ensure consistent lubricant supply; 3. Inspect the nitride layer for peeling (use visual inspection and hardness testing) quarterly.

4

Sheave φ400

101.51.70.03

ZG310-570 cast steel (sheave groove surface carburized, hardness HRC 55-60, precision ground)

1. Uneven groove wear from wire rope misalignment; 2. Thermal fatigue cracking from high-speed, high-load friction; 3. Corrosion from drilling fluid intrusion.

1. Install a wire rope alignment guide to ensure centering in the sheave groove; 2. Monitor sheave temperature during operation (normal temp <60℃)—stop operation if overheated; 3. Clean the groove surface daily to remove drilling fluid residues.

5

Circlip

101.51.70.04

65Mn spring steel (heat-treated, hardness HRC 42-48, surface passivated)

1. Elastic fatigue from long-term radial compression; 2. Corrosion-induced brittleness; 3. Ear damage during installation/disassembly.

1. Use dedicated circlip pliers with non-slip jaws to avoid ear damage; 2. Replace circlips if they show signs of reduced elasticity (e.g., failure to snap into groove); 3. Store in a sealed container to prevent moisture exposure.

6

Seal disc

101.51.70.05

NBR nitrile rubber (Shore hardness 70±5) with steel skeleton (Q235A)

1. Aging and cracking from high temperature and oil contamination; 2. Sealing lip damage from foreign particles; 3. Deformation from excessive assembly pressure.

1. Use high-temperature resistant NBR rubber (for operating temps up to 120℃) in high-heat environments; 2. Install a pre-filter to prevent foreign particles from reaching the sealing surface; 3. Use a press-fit tool to ensure uniform assembly pressure.

7

Inner spacer

101.51.70.06

20# carbon steel (precision machined, surface roughness Ra 1.6μm)

1. Axial wear from frictional contact; 2. Deformation from uneven axial preload; 3. Corrosion from lubrication deficiency.

1. Use anti-friction composite spacers for high-load, high-vibration applications; 2. Calibrate axial preload using a load cell during assembly; 3. Reapply lubricating oil every 150 working hours.

8

Retainer 42

101.51.70.07

Q235A carbon steel (stamped and formed, surface hot-dip galvanized)

1. Shear failure due to high axial loads; 2. Galvanized layer peeling and corrosion; 3. Deformation from storage/transportation damage.

1. Upgrade to stainless steel retainers for corrosive environments; 2. Store retainers in a horizontal position to avoid bending; 3. Inspect for galvanized layer integrity before each use.

9

Pin shaft φ55X310

101.51.80.01

40CrNiMo alloy steel (quenched and tempered, hardness HRC 32-38, surface chrome-plated)

1. Bending deformation from heavy lateral loads; 2. Chrome layer peeling from impact or improper lubrication; 3. Fatigue cracking at the shaft end.

1. Conduct load testing before installation to verify load-bearing capacity; 2. Use compatible lubricants to avoid chrome layer degradation; 3. Inspect for cracks using magnetic particle testing every 4 months.

10

Safety chain

101.51.70.09

20Mn2 alloy steel (welded chain links, surface galvanized, tensile strength ≥800MPa)

1. Fatigue wear from repeated tension; 2. Weld joint corrosion; 3. Fracture from overloading.

1. Conduct tensile testing annually to verify structural integrity; 2. Clean weld joints with a wire brush and reapply anti-rust oil monthly; 3. Mark the chain with load limits to prevent overloading.

11

Clip 120Xφ60Xφ6

101.51.00.01

Q235A carbon steel (stamped, surface phosphatized)

1. Deformation from excessive clamping force; 2. Wear at contact surfaces due to vibration; 3. Corrosion from moisture.

1. Use a torque-limiting tool to apply the correct clamping force; 2. Install a rubber gasket between the clip and the mating surface to reduce wear; 3. Inspect for deformation and corrosion quarterly.

12

Bolt M12X20

GB32-76(M12X20-6.8)

6.8-grade carbon steel (Q355B), surface galvanized

1. Fatigue failure from intense vibration in deep drilling; 2. Thread stripping from over-tightening; 3. Corrosion of the galvanized layer.

1. Use lock nuts or thread-locking adhesive to prevent loosening; 2. Torque to 45-50 N·m using a calibrated torque wrench; 3. Inspect for rust and tightness weekly during operation.

13

Galvanic iron wire φ2

GB343-82-φ2A.R.

Low-carbon steel (08F), galvanized, annealed for ductility

1. Fatigue breakage from repeated bending; 2. Galvanic corrosion in multi-metal assemblies; 3. Tensile failure from overloading.

1. Avoid using the wire in direct contact with dissimilar metals (e.g., aluminum) to prevent galvanic corrosion; 2. Use the minimum necessary bending radius during installation; 3. Replace with new wire after each use.

14

Bearing 42316

GB283-64(42316)

High-carbon chromium bearing steel (GCr15), cage made of brass (H62)

1. Seizure due to contamination or insufficient lubrication; 2. Rolling element fatigue from high loads; 3. Cage damage from misalignment.

1. Use a sealed bearing variant to prevent contamination in harsh environments; 2. Implement a scheduled lubrication program (every 180 working hours); 3. Ensure proper alignment of the bearing inner/outer rings (misalignment tolerance ≤0.5°).

15

Ale mite M10X1

GB1152-79(M10X1)

45# carbon steel (heat-treated, hardness HRC 25-30, surface phosphatized)

1. Thread wear from repeated assembly/disassembly; 2. Deformation from improper tool use; 3. Corrosion from moisture ingress.

1. Use a socket wrench with the correct size to avoid damaging the hex head; 2. Apply anti-seize compound to the threads for easy disassembly; 3. Store in a dry environment and inspect for thread damage before use.