RE 92202
/02.2015,
Bosch Rexroth AG
Axial piston variable pump |
A7VO Series 63
Installation instructions
41
Installation instructions
General
At commissioning and during operation, the axial piston
unit must be filled with hydraulic fluid and air bled. This
must also be observed following a long standstill as the
axial piston unit can empty via the hydraulic lines.
Particularly in the installation position "drive shaft
upwards", filling and air bleeding must be carried out com-
pletely as there is, for example, a danger of dry running.
The pump housing is internally connected to the suction
chamber. A separate drain line from the case to the reser-
voir is not needed. Exception: For versions with pressure
controller or pressure cut-off, a drain line is needed to
relieve port
T
1
to the reservoir.
To achieve favorable noise values, decouple all connecting
lines using elastic elements.
In all operating conditions, the suction line and the drain
line must flow into the reservoir below the minimum fluid
level. The minimum suction pressure at port
S
must not fall
below 0.8 bar absolute during operation either.
When designing the reservoir, ensure that there is adequate
spacing between the suction line and the drain line. This
minimizes oil turbulence and carries out degassing, which
prevents the heated hydraulic fluid from being sucked
directly back in again.
Notes
▶ Axial piston units with electric components (e.g. elec-
tric controls, sensors) must not be installed in a reser-
voir below the fluid level.
▶ In certain installation conditions, an influence on the
control characteristic curves can be expected. Gravity,
dead weight and case pressure can cause minor shifts
in characteristics and changes in response time.
Key
R
1
/R
2
Air bleed port
U
Bearing flushing
S
Suction port
T
1
Control fluid drain
h
t min
Minimum required immersion depth (200 mm)
h
min
Minimum required spacing to reservoir base
(100 mm)
SB
Baffle (baffle plate)
Installation position
See the following examples
1
to
4
.
Additional installation positions are available upon request.
Recommended installation position:
1
and
2
.
Installation position
Air
bleeding
Filling
1
R
1
S
R
2
R
1
T
1
U
S
SB
h
min
h
t min
2
R
2
S
R
2
R
1
T
1
U
S
SB
h
min
h
t min
3
T
1
S
R
2
R
1
T
1
U
S
SB
h
min
h
t min
4
U
S
R
2
R
1
T
1
U
S
SB
h
min
h
t min