Product details:

Ships with a shaft system pressure greater than the normal specification pressure (0.6MPa) and requiring centering requirements are suitable for using this type of high pressure intermediate bearing.

1. Definition and location

The intermediate bearing of the shaft system is an important component of the ship's shaft system. It is installed in the middle position of the ship's shaft system, on the shaft section between the main engine (such as the ship's engine) and the tail shaft (the shaft connecting the propeller). Its main function is to support the transmission shaft and reduce deformation and vibration of the shaft during operation.

2. Structural composition

Bearing seat: generally made of cast iron or cast steel, providing installation foundation and support structure for bearings. Its shape design should consider being able to be stably installed on the hull structure, and ensure sufficient strength and stiffness to withstand the weight of the shaft system and various forces generated during operation.

Bearing shell: It is the part that directly contacts the transmission shaft and is usually made of materials with good wear resistance and anti friction properties such as Babbitt alloy. The inner surface of the bearing shell is a working surface that matches the journal, and its shape and dimensional accuracy are highly required to ensure good contact and lubrication with the journal.

Lubrication system: including lubrication oil tank, oil hole, etc. Lubricating oil can reduce the friction coefficient between the shaft and the bearing shell, reduce wear, and also take away the heat generated by friction. Some intermediate bearings are also equipped with specialized oil cooling devices to ensure that the temperature of the lubricating oil is within the appropriate range.

3. Working principle

When the shaft system is running, the journal of the transmission shaft rotates on the surface of the bearing shell of the intermediate bearing. Due to the presence of a lubricating oil film between the bearing shell and the journal, the solid friction between the two becomes liquid friction or mixed friction (boundary friction and liquid friction coexist). In an ideal lubrication state, lubricating oil will form a sufficiently thick oil film to separate the journal and bearing, thereby reducing friction and effectively absorbing and dispersing the vibration and impact forces generated by the operation of the shaft system.

4. Common faults and maintenance

Wear and tear fault

Reason: It may be due to insufficient lubricating oil, contamination of lubricating oil, misalignment of the shaft system, or inappropriate clearance between the bearing and the journal. For example, if impurities such as metal particles, sand particles, etc. are mixed into the lubricating oil, these impurities will embed on the surface of the bearing or roll between the journal and the bearing, thereby exacerbating wear.

Maintenance measures: Regularly check the quality and quantity of lubricating oil to ensure its cleanliness. If wear is found, it is necessary to replace the bearing shell or repair the journal in a timely manner, and adjust the gap between the bearing shell and the journal.

• Heating malfunction

Reason: The main reason is that the heat generated by friction cannot be dissipated in a timely manner, which may be due to a malfunction in the cooling system of the lubricating oil or poor heat dissipation conditions of the bearings. For example, a clogged oil cooler can cause the lubricating oil temperature to become too high, which in turn can cause the bearing temperature to rise.

Maintenance measures: Check the cooling system, clean the cooler, ensure good heat dissipation channels, and pay attention to controlling the load of the shaft system to avoid long-term operation under high load conditions.

• Vibration malfunction

Reason: Unbalanced shaft system, misaligned shaft system, damaged bearings, etc. can all cause vibration of the shaft system. For example, propeller damage leading to shaft imbalance can cause vibration of the intermediate bearings.

Maintenance measures: Check the balance status of the shaft system through dynamic balance testing and other means, check the alignment of the shaft system, and replace damaged bearings in a timely manner.