6.2.1 Main lubricating oil pump
For security of supply the main lubricating oil pump is driven directly from the main rotating line. On older units, this was a gear-driven positive displacement gear pump. On modern units, the large volume of oil required (around 100 litres/s) enables a centrifugal pump to be used economically.
A typical example is shown in Fig 2.55.
The pump is not self-priming and requires a suction oil pressure of around 3-4 bar.