Bosch Rexroth Corp.
, RE-A 91610/12.2015
10
A6VM series 71 | Axial piston variable motor
HP – Proportional hydraulic control
HP – Proportional hydraulic control
The proportional hydraulic control provides infinite adjust-
ment of the displacement. The control is proportional to
the pilot pressure applied to port X.
HP1, HP2 positive control
▶ Beginning of control at
V
g min
(minimum torque, maxi-
mum permissible speed at minimum pilot pressure)
▶ End of control at
V
g max
(maximum torque, minimum
speed at maximum pilot pressure)
HP5, HP6 negative control
▶ Beginning of control at
V
g max
(maximum torque, mini-
mum speed at minimum pilot pressure)
▶ End of control at
V
g min
(minimum torque, maximum
permissible speed at maximum pilot pressure)
Note
▶ Maximum permissible pilot pressure:
p
St
= 1450 psi (100 bar)
▶ The control oil is internally taken from the high pressure
side of the motor (A or B). For reliable control, an oper-
ating pressure of at least 435 psi (30 bar) is required in
A (B). If a control operation is performed at an operat-
ing 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.
▶ Please state the desired beginning of control in plain text
when ordering, e. g.: beginning of control at 145 psi (10 bar).
▶ The beginning of control and the HP characteristic curve
are influenced by the case pressure. An increase in case
pressure causes an increase in the beginning of control
(see page 6) and thus a parallel displacement of the
characteristic.
▶ A leakage flow of maximum 0.08 gpm (0.3 l/min) can
escape at port X due to internal leakage (operating pres-
sure > pilot pressure). The control is to be suitably
configured to avoid an independent build-up of pilot
pressure.
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
HP without damping.
HP.D with throttle pin on both sides, symmetrical (as to
table)
Option with Size 60 to 215
HP with throttle pin on both sides, symmetrical (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 0.026
[mm] 0.45
0.45
0.55
0.55
0.55
0.65
HP1, HP5 pilot pressure increase
Δp
St
= 145 psi (10 bar)
HP1 positive control
A pilot pressure increase of 145 psi (10 bar) at port X
results in an increase in displacement from
V
g min
to
V
g max
.
HP5 negative control
A pilot pressure increase of 145 psi (10 bar) at port X
results in a decrease in displacement from
V
g max
to
V
g min
.
▶ Beginning of control, setting range 30 to 290 psi (2 to
20 bar)
▶ Standard setting:
Beginning of control at 45 psi (3 bar) (end of control at
190 psi (13 bar))
▼ Characteristic curve
0 0.2 0.4 0.6 0.8 1.0
V
g min
V
g max
V
g
/
V
g max
HP5
HP1
510 (35)
435 (30)
365 (25)
290 (20)
220 (15)
175 (12)
145 (10)
75 (5)
30 (2)
Beginning of contr
ol
se
tting r
ange
Displacement
Pilo
t pr
es
sur
e
p
St
[psi (bar)]
Pilo
t
pr
es
sur
e
incr
ease
