English to Swedish Tech/Engineering Energy / Power Generation

Depression förekommer i en handbok för en synkrongenerator i avsnittet om lagren:

There is a seal carrier at each end of each bearing housing. The outboard carrier has an oil seal nearest the bearing and an air seal on the outside. The carrier casing is drilled and tapped for vibration probes, and the holes are plugged if they are not used. The NDE outboard seal carrier also has a hole for a key phasor, which is plugged if it is not used.
The inboard carrier is similar, but the air seal is double, and the space between the double air seal and the oil seal is vented to atmosphere so that the depression created by the shaft fan does not draw oil from the bearing.

Kan det översättas med Undertryck? Alltså att axelfläkten skapar ett undertryck? Eller Vakuum?