The stern shaft is a critical component of a vessel’s propulsion system, transferring power from the engine to the propeller. To reduce friction and prevent wear, the stern bearing that houses the shaft must be lubricated—either by oil or water.
For most medium and small vessels, especially those operating inland, oil lubrication is the preferred method. Here are the advantages that make oil lubrication stand out:
Oil has better lubricating properties than water, forming a stable oil film that reduces friction and wear. This is especially important in long-term operations and when high engine loads are involved.
Oil-lubricated stern bearings are equipped with high-performance sealing devices that effectively block seawater and mud from entering the stern tube. This significantly reduces the risk of corrosion and contamination.
White alloy bearings used in oil-lubricated systems have a high oil film bearing capacity. With less contact wear and reduced exposure to contaminants, the stern bearings experience minimal wear, leading to longer service life.
Oil-lubricated systems operate in a closed environment, eliminating the need for a copper sleeve in the stern bearing. This also reduces maintenance requirements and simplifies system design.
The closed oil lubrication system offers a more consistent operating condition, helping to maintain the stability of the engine and shaft system. This improves the overall efficiency and reliability of vessel operations.
Conclusion:
While water lubrication may be used in certain marine applications, oil lubrication remains the default and recommended choice for many vessels due to its superior performance, excellent sealing, and low maintenance needs. Unless otherwise specified by the customer, Sinooutput provides marine stern shafts with oil lubrication to ensure optimal durability and operational stability.
If you’re unsure which lubrication system is right for your vessel, the Sinooutput technical team is here to assist with tailored solutions based on your vessel type, application, and operating environment.
