External gear pump | AZPB
15
Multiple gear pumps
Multiple gear pumps
Gear pumps are well-suited to multiple arrangements, with
the drive shaft of the first pump stage is extended to a
second and possibly third pump stage. The shafts for each
pump section are typically connected via a driver.
The individual pump stages are usually hydraulically
isolated and have separate suction ports. A joint suction
port or separate suction ports that are hydraulically
connected is available on request.
Standard through drive (tang drive coupling)
For Platform B pumps, the driver for the next pump stage
can support loads up to Mmax = 25 Nm. This may result in
pressure limitations for subsequent pump stages.
Subsequent pumps of a smaller series determine the max.
transmissible torque.
Mmꢀꢁ
For the configuration of multiple pumps, Bosch Rexroth
recommends arranging the pump stage with the largest
displacement on the drive side.
AZP
AZP
Notice
max [Nm]1)
25
Subsequent pump
Platform B AZPB
M
▶ Attention: The parameters of each pump generally
apply, however certain restrictions need to be obser-
ved:
▶ Max. rotational speed: This is determined by the
largest pump stage used.
▶ Pressures: These are limited by the max. transmissible
torques from drive shaft, through drive and driver.
Compounding of drive torques
With multiple pumps, note that the drive torques of the
subsequent stages compound according to the following
formula:
Δp1; Vg1
Δp2; Vg2
Δp3; Vg3
M
Δp1 × Vg1 + Δp2 × Vg2 + Δp3 × Vg3
18 × π
Δp [bar]
Vg [cm3]
1)
≤ Mmax
This may result in pressure limitations in each pump stage.
1) For Mmax, see chapter “Max. transmissible drive torques”.
RE 10088/01.2019, Bosch Rexroth AG