The vacuum pump includes at least one oil circuit installed with a pressure-producing pump. The oil circulation amounts to a multiple of the amount which would be necessary for pure lubrication purposes. The oil flow is divided into a small stream (2) for lubrication and a large stream (4) for cooling. The one or two oil circuits are driven by one or two oil pumps with one circuit operated at high pressure and lower volume flow and the other at low pressure and higher volume flow for undertaking different tasks.
