Bosch Rexroth A7VO 63 Series Manual page 11

LR... – Power controller with stroke limiter
Due to the hydraulic stroke limiter, it is possible to change
or limit the displacement of the pump continuously across
the entire control range. The displacement is set propor-
tionally using the pilot pressure p
(maximum of 40 bar).
The power control overrides the hydraulic stroke limiter, i.e.
below the power characteristic (hyperbolic characteristic),
the displacement is controlled in dependence on the pilot
pressure. If the set flow or operating pressure exceeds the
power control characteristic, the power control overrides
and reduces the displacement along the hyperbolic charac-
teristic.
A control pressure of 40 bar is needed to swivel the pump
from its initial position V
g max
The necessary control power is taken from the operating
pressure or the external control pressure applied to port Y
To ensure that the stroke limiter functions at a low operat-
ing pressure of < 40 bar, port Y
external control pressure of about 40 bar.
LRH1 – Hydraulic stroke limiter (negative control)
▶ Control from V to V
g max
As the pilot pressure increases, the pump swivels to a
smaller displacement.
▶ Start of control (at V
g max
When ordering, state the start of control in plain text.
▶ Initial position without pilot signal (pilot pressure): V
▼ Characteristic curve LRH1
control pressure increase (V
40
35
30
25
20
15
10
5
4
0 0.2 0.4
Displacement V
applied to port X
St
to V .
g min
must be supplied with an
3
g min
) can be set to 4 to 15 bar
– V ) Δp = 25 bar
g max g min
0.6 0.8 1.0
/V
g g max
Axial piston variable pump | A7VO Series 63
LR – Power controller without power override
▼ Schematic LRH1
1
U R
1
.
3
R
2
▼ Schematic LRDH1
g max
U R
1
R
2
X
1
V
g min
V
g max
X
1
V
g min
V
g max
RE 92202/02.2015, Bosch Rexroth AG
11
Y
3
B(A)
A
1
X
3
T
1
S
M
1
Y
3
B(A)
A
1
X
3
T
1
S
M
1