Bosch Rexroth A7VO 63 Series - HD - Proportional Hydraulic Control; Characteristic Curve HD1 Positive Control; Schematic HD

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
) Δp=10bar
40
35
30
25
20
15
10
5
4
0 0.6 0.8 1.00.40.2
Displacement V
g
/V
g max
Pilot pressure 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