Commissioning 47/68
RE 92004-01-B/05.2017, A4VG Series 40,
Bosch Rexroth AG
8.1.1 Filling the axial piston unit
Professional filling and air bleeding is necessary to prevent damage to the axial
piston unit and to maintain correct function.
The axial piston unit should be filled with a filling unit (10 µm filter grade). The
axial piston unit must not be operated while it is being filled by the filling unit.
Use only a hydraulic fluid that conforms to the following requirements:
You can find details of the minimum requirements on hydraulic fluids in Bosch Rexroth
data sheets 90220, 90221, 90222, and 90225. The titles of the data sheets can be found
in Table 1 “Required and supplementary documentation” on page 5. You can find
details on the permissible and optimal viscosity in data sheet 92004.
To ensure the functional reliability of the axial piston unit, cleanliness level 20/18/15
according to at least ISO 4406 is necessary for the hydraulic fluid. At very high
hydraulic fluid temperatures (
m110 °C, measured at port
T
), a cleanliness
level of at least 19/17/14 according to ISO 4406 is necessary. For permissible
temperatures, see data sheet 92004.
1.
Place a drip tray under the axial piston unit to collect any hydraulic fluid that may
leak.
nOTICE!
Contaminated hydraulic fluid!
The cleanliness levels of hydraulic fluids on delivery do not normally conform to the
requirements for our components.
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Use a suitable filter system to filter hydraulic fluids during filling to minimize solid
impurities and water in the hydraulic system.
2.
Fill and air bleed the axial piston unit via the appropriate ports, see chapter 7.3 “Instal-
lation position” on page 31. The hydraulic lines of the system must also be filled.
nOTICE!
Risk of property damage due to inadequate lubrication!
Product can get damaged or destroyed!
▶
When using a shut-off valve in the suction and/or drain line, make sure that the
drive of the axial piston unit can only be started when the shut-off valves are
open.
3.
When using a shut-off valve in the suction and/or drain line, only operate the axial
piston unit when the shut-off valves are open.
4.
Test the direction of rotation of the drive motor. To do this, rotate the drive motor
briefly at the lowest rotational speed (inching). Make sure that the direction of
rotation of the axial piston unit agrees with the details of the name plate, see
chapter 5.4 “Product identification”, Fig. 4: Name plate A4VG on page 24.
5.
Operate the axial piston pump at a lower rotational speed (starter speed for
internal combustion engines or inching operation for electric motors) until the
hydraulic system is completely filled and air bled. For checking purposes, drain
the hydraulic fluid at the drain port and wait until it drains without bubbles.
