BoschRexrothAG, RE 92050-01-X-B2/2019-08-23
4 A4VSO Series 10, 11 and 30 | Axial piston variable pump
Hydraulic fluids
Hydraulic fluids
The A4VSO ATEX variable pump isdesigned for operation
with HLP mineral oil according toDIN51524.
See thefollowing datasheets forapplication instructions
and requirements forhydraulic fluids before thestart
ofproject planning:
▶ 90220: Hydraulic fluids based onmineral oils and
related hydrocarbons
Information onthe selection ofhydraulic fluid
Selection ofhydraulic fluid shall make surethat the
operating viscosity inthe operating temperature range
iswithin the optimum range (ν
opt
; see selection diagram).
Please note
The leakage temperature which isinfluenced bypressure
and rotational speed isalways above the reservoir
temperature.
Temperature class T4 and T3 as to ATEX:
Safety instructions, see page 5
Ignition temperature of hydraulic fluid
The pump is approved for temperature class T4 to T1
according to DINENISO80079-36.
Under DINENISO80079-37, only hydraulic fluids with an
ignition temperature at least 50K above the maximum
surface temperature of the approved temperature class
should be used. Example: For the temperature class T4,
the ignition temperature of the hydraulic fluid should be
≥185°C.
Viscosity and temperature ofhydraulic fluids
Viscosity Temperature Comment
Cold start
ν
max
≤1000mm
2
/s θ
St
≥-20 °C t≤3 min, without load p≤50bar
Maximum permissible temperature difference between axial
piston unit and hydraulic fluid inthe system maximum 25K
Warm-up phase
ν=1000 to 100mm
2
/s θ≥ -25°C For p
nom
,
0.5×n
max
und t≤15min
Continuous operation
ν=100 to 16mm
2
/s T3
θ=-20°C to +90°C
T4
θ=-20°C to +80°C
Measured at the drain port
Observe the permissible temperature range of the shaft seal
ν
opt
=36 to 16mm
2
/s
optimal operating viscosity and efficiency range
Short-term operation
ν
min
≤16 to 10mm
2
/s θ
max
=+90°C t<3 min, p<0.3×p
nom
▼ Selection diagram
-25 -10 10 30 50 8070 90
0
10
40
60
20
100
200
400
600
1000
16
36
VG 22
VG 32
VG 46
VG 68
VG 100
Optimum operating viscosity range v
opt
Optimum efficiency
Maximum permissible viscosity oncold start
Minimum permissible viscosity for short-term operation
Temperature θ [°C]
Viscosity v [mm
2
/s]
Minimum permissible temperature on cold start