Technical Data 3 - REXROTH A2FO Series Manual

RE 91 401/09.00 | A2FO
Technical Data
Fluid
To review the application of A2FO pumps with the selected hydraulic
fluid, detailed fluid compatibility and application data can be found
in data sheets RE 90220 (mineral oil), RE 90221 (environmentally
acceptable hydraulic fluids) and RE 90223 (fire resistant fluids, HF).
The fixed pump A2FO is not suitable for operation with HFA. When
using HFB-, HFC-, HFD- or environmentally acceptable hydraulic fluids
possible limitations for the technical data have to be taken into
consideration. If necessary please consult our technical department
(please indicate type of the hydraulic fluid used for your application
on the order sheet).
Operating viscosity range
In order to optain optimum efficiency and service life, we recommend
that the operating viscosity (at operating temperature) be selected
from within the range:
ν
= operating viscosity 16...36 mm
opt
referred to the tank temperature (open circuit).
Viscosity limits
The limiting values for viscosity are as follows:
Sizes 5...200
ν
2
= 5 mm /s,
min
short term at a max. permissible temperature of t
ν
= 1600 mm 2 /s,
max
short term on cold start (t
Sizes 250...1000
ν
2
= 10 mm /s,
min
short term at a max. permissible leakage oil temp. of t
ν
2
= 1000 mm /s,
max
short term on cold start (t
Please note that the max. fluid temperature is also not exceeded in
certain areas (for instance bearing area).
At temperatures of -25°C up to -40°C special measures may be
required for certain installation positions. Please contact us for
further information.
Selection diagram
2500
-40° -20° 0° 20°
1600
1000
600
400
200
100
60
40
20
10
5
-40° -25° -10° 0° 10°
fluid temperature range
t = -40°C
min
2
/s
= 115°C
max
= -40°C)
min
= 90°
max
= -25°C)
min
40° 60° 80° 100°
1600
36
ν
16
5
30° 50° 70° 90° 115°
temperature t (°C)
t = +115°C
max
Mobile Hydraulics | Bosch Rexroth AG
Notes on the selection of the hydraulic fluid
In order to select the correct fluid, it is necessary to know the operating
temperature in the tank (open circuit) in relation to the ambient
temperature.
The hydraulic fluid should be selected so that within the operating
temperature range, the operating viscosity lies within the optimum
range (ν ) (see shaded section of the selection diagram). We
opt
recommend that the highest possible viscosity range should be chosen
in each case.
Example: At an ambient temperature of X°C the operating
temperature is 60°C. Within the operating viscosity range (ν
area), this corresponds to viscosity ranges VG 46 or VG 68. VG 68
should be selected.
Important: The leakage oil (case drain oil) temperature is influenced
by pressure and pump speed and is always higher than the tank
temperature. However, at no point in the circuit may the temperature
exceed 115°C for sizes 5...200 or 90°C for sizes 250...1000.
If it is not possible to comply with the above conditions because of
extreme operating parameters or high ambient temperatures please
consult us.
Filtration
The finer the filtration the better the achieved cleanliness level of the
pressure fluid and the longer the life of the axial piston unit.
To ensure the functioning of the axial piston unit a minimum
cleanliness level of
9 to NAS 1638
18/15 to ISO/DIS 4406 is necessary.
At very high temperatures of the hydraulic fluid (90°C to max. 115°C,
not permissible for sizes 250...1000!) at least cleanliness level
8 to NAS 1638
17/14 to ISO/DIS 4406 is necessary.
If above mentioned grades cannot be maintained please consult
supplier.
Direction of flow
clockwise rotation
S to B
Symbol
Connections
A, B Service line ports
S Suction port
T Drain port
opt.
U Port for bearing flushing
(sizes 250...1000)
3/20
; shaded
opt
anti-clockwise rotation
S to A
B (A)
T S U