Bosch rexroth A21VG 10 Series - Hydraulically connecting the axial piston unit

34/56 Installation
Bosch Rexroth Corporation, A21VG Series 10, RE 93223-01-B/09.2020
7.4.8 Hydraulically connecting the axial piston unit
NOTICE
Insufcient suction pressure!
Generally, a minimum permissible suction pressure at port “S” is specied for
axial piston pumps with boost pump in all installation positions. If the pressure at
port “S” drops below the specied values, damage may occur which may lead to
the axial piston pump being damaged beyond repair!
▶ Make sure that the necessary suction pressure is not undercut. This is
inuenced by:
– the piping (e.g. suction cross-section, pipe diameter, length of suction line)
– the position of the reservoir
– the viscosity of the hydraulic uid
– if tted, a lter cartridge or check valve in the suction line (regularly check
the level of soiling of the lter cartridge)
The machine/system manufacturer is responsible for dimensioning the lines.
The axial piston unit must be connected to the rest of the hydraulic system in
accordance with the hydraulic schematic of the machine/system manufacturer.
The ports and fastening thread are designed for the maximum pressure specied in
the data sheet. The machine/system manufacturer must ensure that the connecting
elements and lines correspond to the specied application conditions (pressure,
ow, hydraulic uid, temperature) with the necessary safety factors.
Connect only hydraulic lines that are appropriate for the axial piston unit port
(pressure level, size, system of units).
Observe the following notes when routing the suction, pressure and reservoir
lines.
• Lines and hoses must be installed without pre-charge pressure, so that no further
mechanical forces are applied during operation that will reduce the service life of
the axial piston unit and, if applicable, the entire machine/system.
• Use suitable seals as sealing material.
• Suction line (pipe or hose)
– The suction line should be as short and straight as possible.
– Measure the line cross section of the suction line so that the pressure at the
suction port does not drop below the minimum permissible pressure. Make
sure that the maximum suction pressure is not exceeded (e.g. when pre-lling).
– Make sure the connections and connecting elements are air-tight.
– The hose must be pressure-resistant, also for external air pressure.
• Pressure line
– For the pressure lines, use only pipes, hoses and connecting elements rated for
the operating pressure range specied in data sheet 93223 (see Table 10).
Notes on routing the lines