RE-A 91610/12.2015,
Bosch Rexroth Corp.
Axial piston variable motor | A6VM series 71
HA – Automatic high-pressure related control
17
HA – Automatic high-pressure related control
The automatic high-pressure related control adjusts the
displacement automatically depending on the operating
pressure.
The displacement of the A6VM motor with HA control is
V
g min
(maximum speed and minimum torque). The control
unit internally measures the operating pressure at A or B
(no control line required) and upon reaching the set begin-
ning of control, the controller swivels the motor from
V
g min
to
V
g max
with increase of operating pressure. The displace-
ment is modulated between
V
g min
and
V
g max
, thereby
depending on load conditions.
HA1, HA2 positive control
▶ Beginning of control at
V
g min
(minimum torque, maxi-
mum speed)
▶ End of control at
V
g max
(maximum torque, minimum
speed)
Note
▶ For safety reasons, winch drives are not permissible
with beginning of control at
V
g min
(standard for HA).
▶ The control oil is internally taken out of the high pres-
sure side of the motor (A or B). For reliable control, an
operating pressure of at least 435 psi (30 bar) is
required in A (B). If a control operation is performed at
an operating pressure < 435 psi (30 bar), an auxiliary
pressure of at least 435 psi (30 bar) must be applied at
port G via an external check valve. For lower pressures,
please contact us.
Please note that pressures up to 7250 psi (500 bar) can
occur at port G.
▶ The beginning of control and the HA.T3 characteristic
curve are influenced by case pressure. An increase in
case pressure causes an increase in the beginning of
control (see page 6) and thus a parallel shift of the
characteristic.
Response time damping
The response time damping is influencing the stroke char-
acteristics of the motor and thus the reaction speed of the
machine.
Standard with Size 60 to 215
HA1,2 with one-sided throttle pin, the throttling occurs
from
V
g min
to
V
g max
. (as to table)
▼ Overview Throttle Pins
Size
60
85
115
150
170
215
Groove
size
[inch] 0.018 0.018 0.022 0.022 0.022 0.022
[mm] 0.45
0.45
0.55
0.55
0.55
0.65
Standard with Size 60 to 215
HA1, 2 with one sided throttle pin effects the stroking time
of
the motor from Vg min to Vg max. (as to table)
▼ Overview Throttle Screw
Size
60
85
115
150
170
215
Groove
size
[inch] 0.031 0.031 0.031 0.031 0.031 0.031
[mm] 0.80
0.80
0.80
0.80
0.80
0.80
