Page 88
EN
4.2.2 Oil supply unit with ilter unit
4.2.2.1 Oil supply unit
The oil supply unit consists of two gear
pumps, one of which is used as a standby
pump. Changeover of the pumps is performed
by the motor management system.
The lubricating oil is suctioned through the
3-way directional valve (
WV1
) and fed to the
pump (
M/P1
or
M/P2
).
The pump feeds the lubricating oil to the
downstream ilter unit through a check valve
(
RV1
or
RV2
).
A pressure relief valve (
DB1
) protects the ilter
unit against overpressure and switches to tank
refeeding if the pressure rises above 60 bar.
The system pressure is monitored by a pres-
sure sensor
(PT
) connected to the delivery line
of the oil supply unit. If the pump pressure is
too low (below 35 bar), this pressure switches
PT
to the standby pump, which then handles
lubricating oil feeding.
The ilter unit consists of a double ilter; one
of the ilters is used as a standby ilter for
possible ilter replacement under load. Both
ilter elements are equipped with a bypass that
responds at a pressure difference of 7 bar.
An electrical/visual contamination indicator
(
PSA
) checks the differential pressure between
ilter inlet and ilter outlet and passes a fault
notiication to the motor control in the event
of a fault.
Each ilter side contains a check valve (
RV3
or
RV4
), which prevents cleaned lubricating oil
from lowing back during ilter replacement.
The ilters are switched over manually using a
change-over lever (
WV2
).
A vent plug (
V1
or
V2
) provides fast venting
during ilter replacement.
A pressure relief valve (
SV1
) reduces system
pressure to help during maintenance work on
the oil supply unit.
There is also a measurement connector (
C1
or
C2
) on each oil supply unit.
4. Description
- see Figures 4 and 5
