A middle bearing is a type of bearing widely used in machinery and equipment. It is the main support unit in the ship's shafting system, bearing considerable loads during operation. The working performance of the middle bearing directly affects the power performance of the ship's propulsion system.

Therefore, analyzing the lubrication performance of intermediate bearings, effectively predicting the lubrication condition of bearings, optimizing the structural parameters of bearings based on design requirements and analysis results, reducing friction resistance of intermediate bearings, lowering shaft vibration and noise, improving shaft transmission efficiency and reliability, decreasing material wear, and extending service life is of great significance.

Under different speed conditions, the intermediate bearing oil film thickness and film thickness ratio: When the speed is low, the oil film thickness of the intermediate bearing Z is smaller. As the shaft speed increases, the oil film thickness increases, showing an upward trend. This is because with the increase in shaft speed, the relative movement speed between the two lubricating surfaces of the bearing increases, the dynamic pressure effect of the oil film is enhanced, which is conducive to the formation of the oil film, thereby improving the load-bearing capacity of the oil film in the load-bearing area, resulting in an increase in the thickness of the thin oil film.