Bosch Rexroth A7VO 63 Series - LRD - Power Controller with Pressure Cut-off; Characteristic Curve LRD; Schematic LRD

Bosch Rexroth AG, RE 92202/02.2015
10 A7VO Series 63 | Axial piston variable pump
LR – Power controller without power override
LRD – Power controller with pressure cut-off
The pressure cut-off is a pressure control which adjusts the
displacement of the pump back to V
g min
after reaching the
set pressure command value.
This function overrides the power controller, i.e. the power
control function is executed below the pressure command
value.
Pressure cut-off is preset to a pressure command value at
the factory.
▶ Setting range 200 to 350 bar
When ordering, state the setting in plain text.
Notes
▶ The pressure setting of the pressure cut-off must be at
least a factor of 5 higher than the beginning of control
of power control.
Example:
– Beginning of control of the power controller: 50bar
– Minimum setting of pressure cut-off:
5×50=250bar
Higher settings of the pressure cut-off are always
possible.
▶ For versions with pressure cut-off, a drain line is
needed from port T
1
to the reservoir.
When port T
1
is plugged and t
tank
≤50°C, this results
in a permissible pressure cut-off of≤2 min.
▶ Any pressure-relief valve included in the system to limit
the maximum pressure must have its start of opening
at least 20 bar above the pressure cut-off setting.
▼ Characteristic curve LRD
350
200
min
max
V
g min
displacement V
g max
Operating pressure p
B
[bar]
▼ Schematic LRD
T
1
X
3
B(A)
A
1
M
1
R
2
U
R
1
V
g min
V
g max
S