tilting pad journal bearings ZYS
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Tilting-pad journal bearing

A tilting-pad journal bearing, one kind of hydrodynamic bearing/fluid bearing, is mainly under radial load and able to bear a certain impact load and unbalanced load. Generally, there are more than 3 pads on a tilting-pad journal bearing, which are evenly distributed on the base. Mostly, it is designed with odd number of pads. The load direction may be either vertical to the pad center or to the space between two pads. The position of the pad supporting point may be adjusted with load and direction of rotation. When the supporting point is at the pad center, the bearing may be bidirectionally rotated but the bearing capacity is lower than that of unidirectionally rotating bearing. If the pad width approaches the shaft diameter, the bearing is under the highest load.


Incase of double layer composite material, the low carbon steel composite layer of the substrate should be Babbitt alloy. Through axial and radial positioning, the bearing 

makes that the pad is fixed onto the substrate. With proper design of profile and high accuracy machining, the pad may be free inclined under dual action of revolution and 

load, forming oil wedge for dynamic lubrication of bearing. The Babbitt alloy mainly contains tin, lead, copper and antimony. The copper is used to improve the strength and 

hardness of the alloy of which structural features are that hard phase particles are evenly distributed on the soft phase substrate. The soft phase substrate makes that the alloy

 features very good inset, adaptability, and resistance to seizure. And, after running in, the soft substrate is concave and hard particles are convex, so that micro clearance is 

formed between the sliding faces, as an oil storage space and a lubricating oil channel, good to reduction in friction. The concave hard particles function to support, good to 

bearing capacity.



Oil and gas technology is developing at a very rapid pace, and exploiting deeper oil and gas resources in harsher environments means that the top drives need more power to withstand higherloads.When unforeseen downtime costs are as high as $1 million per day, the reliability of equipment becomes particularly important, and the reliability of key parts of the bearing directly determines the performance of the equipment.