Gas Turbine Bearings

Introduction
The MS 9001 E gas turbine unit contains three main journal bearings used to support the gas turbine rotor. The unit also includes thrust bearings to maintain the rotor-to-stator axial position. These bearing assemblies are located in three housings: one at the inlet, one in the compressor discharge casing and one in the exhaust frame. All bearings are pressure lubricated by oil supplied from the main lubricating oil system. The oil flows through branch lines to an inlet in each bearing housing.

Bearing N*. Class Type

1 -Journal Elliptical

2 -Journal Elliptical

3 -Journal Elliptical

1 -Loaded thrust Self-aligned (equalized)

1 -Unloaded thrust Tilting pad


Lubrication
The three main turbine bearings are pressure-lubricated with oil supplied by the 12540 liters capacity lubricating oil reservoir. Oil feed piping, where practical, is run within the lube oil reservoir drain line, or drain channels, as a protective measure. This procedure is referred to as double piping and its rationale is that in the event of a pipe-line leak, oil will not be lost or sprayed on nearby equipment, thus eliminating a potential safety hazard.

When the oil enters the bearing housing inlet, it flows into an annulus around the bearing liner. From the annulus the oil flows through machined slots in the liner to the bearing surface. The oil is prevented from escaping along the turbine shaft by labyrinth seals.


Oil seals
Oil on the surface of the turbine shaft is prevented from being spun along the shaft by oil seals in each of the three bearing housings. These labyrinth packings and oil deflectors (teeth type) are assembled on both sides of the bearing assemblies where oil control is required. A smooth surface is machined on the shaft and the seals are assembled so that only a small clearance exists between the oil and seal deflector and the shaft. The oil seals are designed with two rows of packing and an annular space between them. Pressurized sealing air is admitted into this space and prevents lubricating oil from spreading along the shaft. Some of this air returns with the oil to the main lubricating oil reservoir and is vented through a lube oil vent.


Gas Turbine Bearing Assembly


 Gas Turbine Load Thrust Bearing



Gas Turbine Unload Thrust Bearing

2 comments:

  1. bearings are do their job either it is heavy duty job or lower duty.
    thrust bearings

    ReplyDelete
  2. A typical example for these heavy duty seals are made by Pioneer Motor Bearing Co. Their hydro seal and oil seal glands are quite efficient in this job. http://www.pioneer1.com/engineering/hydrogen-gland-seals-oil-seals/

    ReplyDelete