explain:

This bearing is suitable for ships with various types of oil lubricating media.

Definition and structural characteristics

White alloy cast iron shell bearings are a special type of bearing. Its shell is made of cast iron, which has high strength and rigidity, and can provide a stable support structure for the bearing. The so-called "white alloy" usually refers to Babbitt alloy, which is cast on the inner surface of the cast iron shell and serves as the working surface of the bearing in contact with the journal.

The main components of Babbitt alloy are metals such as tin, lead, antimony, etc. This alloy has a relatively soft texture and can adapt well to the shape changes of the journal when in contact with it. It also has good anti friction and wear resistance. Its structural feature is that under the sturdy support of the cast iron shell, the white alloy working layer can effectively disperse the pressure applied by the journal and reduce local stress concentration.

working principle

When the shaft rotates in the bearing, a lubricating oil film is formed between the white alloy layer and the shaft neck. This oil film is formed by the rotational motion of the shaft neck, which brings lubricating oil into the gap between the white alloy and the shaft neck. The oil film separates the journal from the white alloy layer, transforming the friction between the two from dry friction or boundary friction to liquid friction. In the state of liquid friction, the frictional force is greatly reduced, and the wear of the journal and the white alloy layer is also reduced.

For example, in the application of stern shaft bearings in ships, when the ship is sailing, the stern shaft drives the propeller to rotate, and the stern shaft neck rotates in the white alloy cast iron shell bearing. Lubricating oil enters the gap under the high-speed rotation of the neck, allowing the stern shaft to run smoothly and reducing power loss.

advantage

Good wear resistance: White alloy itself has good wear resistance and can withstand the friction of the shaft neck during rotation. Under normal working conditions, it can maintain a stable working state for a long time, reducing the trouble of frequent bearing replacement.

Good shock absorption performance: Due to the relatively soft surface of the white alloy, during the operation of the shaft neck, when encountering some small impacts or vibrations, the white alloy layer can play a certain buffering role, absorb vibration energy, and reduce the impact on the entire equipment.

Strong load-bearing capacity: The cast iron shell provides sufficient strength support for the bearing, combined with the performance of white alloy, this type of bearing can withstand large radial and axial loads, suitable for some heavy-duty equipment, such as power systems of large ships, heavy machinery, etc.

Disadvantages and countermeasures

High requirements for lubricating oil: In order to ensure good oil film formation, this type of bearing requires the use of lubricating oil with good quality and appropriate viscosity. If the quality of the lubricating oil is poor or the oil film ruptures, it will cause direct contact between the white alloy layer and the journal, resulting in dry friction and accelerated wear. The response measures are to strictly select suitable lubricating oil according to equipment requirements, and regularly inspect and replace the lubricating oil.

White alloy is prone to peeling off: Under some harsh working conditions, such as frequent impact, overload, or poor lubrication, white alloy may peel off from the cast iron shell. To prevent this situation from happening, it is necessary to ensure a strong bond between the white alloy and the cast iron casing during the manufacturing process, and to avoid equipment overload operation and ensure good lubrication conditions during use.

application area

Shipbuilding industry: widely used in stern shaft bearings, main engine bearings and other parts of ships. During the navigation of a ship, the stern shaft needs to withstand the enormous thrust of the propeller and its own gravity. The white alloy cast iron shell bearings can effectively support the stern shaft, ensuring the stable operation of the ship's power system.

Industrial heavy machinery: bearings for equipment such as large motors and rolling mills. These devices usually need to withstand large loads and have high requirements for the stability and wear resistance of bearings. White alloy cast iron shell bearings can meet these requirements.