Ship shaft and rudder system is the key system for ship propulsion and maneuvering, and its fittings include propellers, shaft systems, rudder blades, rudder rods, bearings, sealing devices and so on. These fittings are prone to failure due to wear and tear, corrosion, vibration and other reasons during long-term operation, affecting the normal navigation of the ship. The following are the common failures and solutions of the ship's shaft and rudder system fittings:

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1. Propeller failure

Common Failures:

- Paddle Damage: Propeller blades may be cracked, deformed or broken due to collision, corrosion or air bubble erosion.

- Paddle Imbalance: Uneven wear of the paddle blades or entanglement of foreign objects can cause the propeller to become unbalanced and cause vibration.

- Loose paddle hub: Loose or corroded connecting bolts between the paddle hub and the shaft system cause the propeller to mesh poorly with the shaft system.

Solution:

- Regularly check the surface of the propeller, find cracks or deformation timely repair or replacement.

- Clean the foreign matter on the propeller blade and make sure the surface of the propeller blade is smooth.

- Check and tighten the propeller hub bolts, replace the bolts or carry out anti-corrosion treatment if necessary.

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2. Shaft system failure

Common Failures:

- Bending or breaking of shaft system: The shaft system may be bent or broken due to the vessel running aground, collision or long-term uneven stress.

- Shaft wear: The mating surfaces of the shaft and bearings are worn due to poor lubrication or intrusion of foreign matter.

- Shaft system vibration: Poor shaft system alignment or propeller imbalance will lead to shaft system vibration, affecting the operation of the ship.

Solution:

- Regularly check the alignment of the shaft system to ensure that the shaft system and bearings are well matched.

- Strengthen the lubrication management of the shaft system, use high quality lubricant and replace it regularly.

- Carry out non-destructive testing of the shaft system, and repair or replace the cracks or wear in time.

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3. Rudder blade failure

Common faults:

- Rudder blade deformation or cracks: The rudder blade may be deformed or cracked due to collision, corrosion or long-term stress.

- Stuck rudder blade: The connection between the rudder blade and rudder bar is stuck due to corrosion or foreign matter, resulting in inflexible rotation of the rudder blade.

- Rudder blade corrosion: The surface of the rudder blade is thinned or perforated due to seawater corrosion.

Solution:

- Regularly check the surface of the rudder blade and repair or replace it in time if deformation or cracks are found.

- Clean the corrosion and foreign matter at the connection between the rudder blade and rudder bar to ensure the rudder blade rotates flexibly.

- Carry out anti-corrosion treatment for the rudder blade, such as coating with antirust paint or using corrosion-resistant materials.

4. Tiller shaft malfunction

Common malfunctions:

- Bent or broken rudder rod: The rudder rod may be bent or broken due to collision or prolonged stress.

- Rudder shaft wear: The mating surfaces of the rudder shaft and bearing are worn out due to poor lubrication or intrusion of foreign matter.

- RUDDER ROD VIBRATION: Poor connection between the rudder rod and rudder blade or vibration of the shaft system may cause the rudder rod to vibrate.

Solution:

- Regularly check the centering of the rudder bar to ensure that the rudder bar and bearings are well matched.

- Strengthen the lubrication management of the rudder bar, use high quality lubricant and replace it regularly.

- Carry out non-destructive testing of the rudder bar, and repair or replace the rudder bar in time when cracks or wear are found.

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5. Bearing failure

Common failure:

- Bearing wear: bearings are worn out due to poor lubrication, intrusion of foreign objects or long-term stress.

- Bearing overheating: bearings overheat or even burn out due to insufficient lubrication or poor alignment.

- Bearing vibration: bearing vibration due to poor mounting or shaft system vibration.

Solution:

- Regularly check the lubrication of the bearings to ensure that they are adequately lubricated.

- Check the mounting and alignment of the bearings to ensure that the bearings fit well with the shaft system.

- Carry out non-destructive testing of the bearings and repair or replace them in time when wear or cracks are found.

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6. Failure of sealing device

Common failures:

- Seal failure: The sealing device fails due to aging, wear or poor installation, resulting in water ingress into the shaft system or rudder bar.

- Seal Leakage: The sealing device leaks due to corrosion or intrusion of foreign matter, affecting the safety of the ship.

Solution:

- Regularly check the wear and tear of the sealing device and replace it in time when it is found to be aged or worn.

- Clean the foreign matter around the sealing device to ensure that the sealing device works normally.

- Use high quality sealing materials to improve the durability of the sealing device.

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7. Vibration and noise

Common faults:

- Shaft system vibration: Poor shaft system alignment, propeller imbalance or bearing wear can cause shaft system vibration.

- Rudder system vibration: Poor connection between rudder stick and rudder blade or vibration of shaft system will cause rudder system vibration.

- Noise: Vibration, wear or poor lubrication of the shaft system or rudder system can cause noise.

Solution:

- Regularly check the alignment of the shaft system and rudder system to ensure a good fit.

- Enhance the lubrication management of the shaft system and rudder system, use high quality lubricant and replace it regularly.

- Carry out vibration testing of the shaft system and rudder system, and deal with any abnormalities promptly.

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8. Corrosion problems

Common faults:

- Metal corrosion: Metal parts such as shaft system, rudder rod, rudder blade, etc. are thinned or perforated due to seawater corrosion.

- Electrochemical corrosion: Electrochemical reaction between different metals will accelerate the corrosion.

Solution:

- Anti-corrosion treatment of metal parts, such as coating with antirust paint or using corrosion-resistant materials.

- Install sacrificial anodes to prevent galvanic corrosion.

- Regularly check the corrosion of metal parts and repair or replace them when corrosion is found.

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Summarize

Failure of ship's shaft and rudder system fittings will affect the ship's propulsion and maneuvering performance, and even threaten navigation safety. Therefore, crew and maintenance personnel should regularly check the operation of the shaft and rudder system fittings, and find and deal with the failure in time. By strengthening lubrication management, anticorrosion treatment and alignment inspection, the service life of the shaft and rudder system fittings can be effectively extended to ensure the safe navigation of the ship.