BEARINGS

                                    BEARINGS 

BEARINGS

Bearings take care of the axial and radial loads and reduce the mechanical friction to minimum.  Bearings keep the rotor in proper centre and prevent unnecessary rubbing of moving parts by maintaining the clearances. To keep the bearing operating efficiently, they are lubricated and enclosed in a bearing housing.  

 In simple centrifugal pumps, ball bearings normally used for radial and axial thrust. These are mounted in bearing housing that have a constant oil level, maintained by an oil bottle. Note how the bearings differ in construction, and that the axial thrust bearing is always a double bearing back to back. Oil slinger rings that rotate on the shaft lubricate the bearings. The slinger rings are a larger diameter than shaft and so extended down into the oil level, picking up an oil film on their surfaces and transferring it to the bearing by migration along with the shaft. 

 The bearing housing is maintained under atmospheric pressure by a vent on the top of the bearing box. If the pump is on hot service, (above 175 oC), the bearing housing is cooled by water. 

 

                      JOURNAL TYPE BEARINGS 

These bearings are made up from white metal and are used on heavyduty pumps. Journal bearings take up radial thrust. Because of the low melting point of the white metal, the bearings are sometimes fitted with thermometers and are water-cooled. 

 

KINGS BURRY TYPE THRUST BEARINGS 

KINGS BURRY THRUST BEARING

 

These bearings are also made from white metal and are used to take up axial thrust from the thrust collar on the shaft. In most cases lubrication of these type of bearings is by pump, which circulates oil from a reservoir around the bearings and back to the reservoir via cooler to keep the oil at a constant temperature. There is also some form of heating device so that the oil can be brought to the operating temperature before commissioning.