Turbine bearing

There are two types of turbine bearings: thrust bearings and support bearings:

The support bearing is to bear the weight of the rotor and the centrifugal force generated by the unbalanced mass of the rotor, and determine the radial position of the rotor to ensure that the center of the rotor is consistent with the center of the cylinder to ensure the correct radial clearance between the rotor and the stationary part.

The thrust bearing is to withstand the unbalanced axial thrust on the rotor and determine the axial position of the rotor to ensure the axial clearance between the dynamic and static parts.

Working principle of turbine support bearing

In the sliding support bearing, the inner circular diameter of the bearing bush is slightly larger than the outer diameter of the journal. When the rotor is stationary, the journal is at the bottom of the bearing bush, and a wedge gap is naturally formed between the journal and the bearing bush. If the lubricating oil with a certain pressure and viscosity is continuously supplied to the bearing clearance, when the journal rotates, the lubricating oil will rotate accordingly, and the lubricating oil will be brought from the wide opening to the narrow opening in the clearance on the right. Because the amount of imported oil is greater than the amount of exported oil in this gap, the lubricating oil collects in the narrow wedge gap and the oil pressure increases. When the oil pressure in the gap exceeds the load on the journal, the journal is lifted. After the journal is lifted, the gap increases, the oil pressure decreases, and the journal falls some, until the oil pressure in the gap is balanced with the load, the journal will be stable in a certain position. At this time, the journal and the bearing shell are completely separated by the oil film, forming liquid friction.

The working principle of turbine thrust bearing

The structure of the thrust bearing is to install a number of thrust tiles on the front and back of the reasoning disk. The one on the generator side is generally called the working tile, which mainly bears the forward axial thrust, and the other side is called the non-working tile, which mainly bears the reverse thrust that sometimes occurs instantaneously. After the turbine rotates, the lubricating oil rotates together with the thrust disk and enters the gap between the thrust disk and the tile. When the rotor generates axial thrust, the oil layer in the gap is under pressure and transferred to the thrust tile. Since the thrust is supported eccentrically, the force deflected, thus forming a wedge gap between the turbine and the thrust disk. With the increase of the turbine speed, the oil film is established. At this time, the thrust disc and the thrust tile are completely separated by the oil film, forming liquid friction.