Bosch Rexroth AG
, RE 92202/02.2015
18
A7VO Series 63
| Axial piston variable pump
HD – Proportional hydraulic control
HD – Proportional hydraulic control
The proportional hydraulic control provides continuous
control of the displacement. Control is carried out propor-
tional to the pilot pressure applied at port
X
1
.
▶ Maximum permissible pilot pressure
p
St
= 40 bar
▶ Control from
V
g min
to
V
g max
(positive control)
As the pilot pressure increases, the pump swivels to a
larger displacement.
▶ Start of control (at
V
g min
) can be set to 4 to 15 bar
When ordering, state the start of control in plain text.
A control pressure of 40 bar is needed to swivel the pump
from its initial position
V
g min
to
V
g max
.
The necessary control power is taken from the operating
pressure or the external control pressure applied to port
Y
3
.
To ensure that control is guaranteed at a low operating
pressure of < 40 bar too, port
Y
3
must be supplied with an
external control pressure of about 40 bar.
▼ Characteristic curve HD1 positive control
increase in control pressure (
V
g min
–
V
g max
) Δ
p
= 10 bar
40
35
30
25
20
15
10
5
4
0
0.6
0.8
1.0
0.4
0.2
Displacement
V
g
/
V
g max
Pilo
t pr
es
sur
e
p
St
[bar]
▼ Schematic HD
R
2
U
R
1
V
g min
V
g max
T
1
X
3
X
1
Y
3
B(A)
A
1
M
1
S