Bosch Rexroth A6VM series 71 User Manual

RE-A 91610/12.2015, Bosch Rexroth Corp.
Axial piston variable motor | A6VM series 71
Flushing and boost pressure valve
63
Flushing and boost pressure valve
The flushing and boost pressure valve is used to remove
heat from the hydraulic circuit.
In a closed circuit, it is used for flushing the case and safe-
guarding the minimum boost pressure.
Hydraulic fluid is directed from the respective low pressure
side into the motor housing. This is then fed into the reser-
voir, together with the leakage. The hydraulic fluid, removed
out of the closed circuit must be replaced by cooled
hydraulic fluid from the boost pump.
The valve is mounted onto the port plate or integrated
(depending on the control type and size).
Cracking pressure of pressure retaining valve
(observe when adjusting the primary valve)
▶ Sizes 60 to 215, fixed setting 230psi (16bar)
Switching pressure of flushing spool Δp
▶ Sizes 60 to 215 (small flushing valve) 115±15psi (8±1bar)
▶ Sizes 115 to 215 (medium and large flushing valve)
254±22.5psi (17.5±1.5bar)
Flushing flow q
v
Orifices can be used to adjust the flushing flows as
required. The following information is based on:
Δp
ND
=p
ND
– p
G
=365psi (25bar) and ν=60SUS (10mm
2
/s)
(p
ND
=low pressure, p
G
=case pressure)
Small flushing valve for sizes 60 to 115
Material number
of orifice
DIA [inch] (ø [mm])
q
v
[gpm (l/min)]
Code
R909651766 0.047 (1.2) 0.9 (3.5) A
R909419695 0.055 (1.4) 1.3 (5) B
R909419696 0.071 (1.8) 2.1 (8) C
R909419697 0.079 (2.0) 2.6 (10) D
R909444361 0.094 (2.4) 3.7 (14) F
Medium flushing valve for size 115
Material number
of orifice
DIA [inch] (ø [mm])
q
v
[gpm (l/min)]
Code
R909449997 0.055 (1.4) 1.3 (5) B
R909449998 0.071 (1.8) 2.1 (8) C
R909431308 0.079 (2.0) 2.6 (10) D
R909431309 0.10 (2.5) 3.9 (15) G
R909431310 0.11 (2.8) 4.8 (18) I
R902138235 0.12 (3.1) 5.5 (21) J
R909435172 0.14 (3.5) 7.1 (27) K
R909436622 0.16 (4.0) 8.2 (31) L
Large flushing valve for sizes 150 to 215
Material number
of orifice
DIA [inch] (ø [mm])
q
v
[gpm (l/min)]
Code
R909449997 0.055 (1.4) 1.3 (5) B
R909449998 0.071 (1.8) 2.1 (8) C
R909431308 0.079 (2.0) 2.6 (10) D
R909431309 0.10 (2.5) 3.9 (15) G
R909431310 0.11 (2.8) 4.8 (18) I
R902138235 0.12 (3.1) 5.5 (21) J
R909435172 0.14 (3.5) 7.1 (27) K
R909436622 0.16 (4.0) 8.2 (31) L
R909449967 0.20 (5.0) 9.7 (37) M
▼ Circuit diagram EP
G
T
2
T
1
U
Sa
B
A
V
g min
V
g max
M
1
Flushing
spool
Pressure retain-
ing valve
Flushing
orifice
Information
▶ Port S
a
only for sizes 150 to 215
▶ For a flushing flow greater than 9.2gpm (35l/min), it
is recommended that port S
a
be connected in order to
prevent an increase in case pressure. An increased
case pressure reduces the flushing flow.

Bosch Rexroth A6VM series 71 Specifications

General

Brand	Bosch
Model	Rexroth A6VM series 71
Category	Engine
Language	English