Bosch Rexroth A7VO 63 Series - DR - Pressure Controller; Schematic DR; Characteristic Curve DR

RE 92202/02.2015, Bosch Rexroth AG
Axial piston variable pump | A7VO Series 63
DR – Pressure controller
15
DR – Pressure controller
The pressure control limits the maximum pressure at the
pump outlet within the control range of the variable pump.
The variable pump only delivers as much hydraulic fluid as
is required by the consumers. If the operating pressure
exceeds the setpoint value set at the integrated pressure
valve, the pump control will shift toward a smaller
displacement and the control deviation will decrease.
When depressurized, the pump is swiveled to its initial
position V
gmax
by an adjustment spring.
▶ Setting range of pressure control 50to350bar
When ordering, state the setting in plain text.
Notes
▶ For versions with controller DR, a drain line is needed
from port T
1
to the reservoir.
▶ Any pressure-relief valve included in the system to limit
the maximum pressure must be set to a cracking pres-
sure at least 20bar above the controller setting.
▼ Characteristic curve DR
50
350
max
max. 10 bar
min
q
V min
flow q
V
[l/min] q
V max
Operating pressure p
B
[bar]
▼ Schematic DR
M
1
R
2
U R
1
T
1
X
3
B(A)
A
1
S
V
g min
V
g max
Zero-stroke operation
The standard pump unit is designed for intermittent con-
stant pressure operation. Short-term zero-stroke operation
(< 1min.) is permissible up to an operating pressure
p
max
=315bar at a reservoir temperature of ≤50°C.
In the case of longer zero-stroke operation (> 1 min),
bearing flushing should be carried out via flushing port U.
U
R
1
S
T
1
R
2
Flow port
Flushing flow (recommended)
NG 28 55 80 107 160
q
V flush
l/min 3 4 6 8 12
Temperature of flushing fluid ≤ reservoir temperature