Technical data

Owing to the turning points inevitably present in pipeline systems
(e.g. 90-degree elbows), high pressure losses develop in the cool-
ing lines. For that reason, we recommend that tubing systems be
used.
When selecting the coolant lines, please be absolutely sure to take
the pressure drop within the system into consideration. If greater
lengths are used, the inside diameter of the lines should, therefore,
at least be 9 mm and be reduced only shortly before being connec-
ted to the motor.
The data specified in the documentation relate to water as coolant.
Operating pressure
A maximum coolant supply pressure of 3 bar applies to all MSK motors, re-
garding the pressure effectively existing directly at the coolant connection of
the motor.
Please note that additional screwed or branch connections in the cooling circuit
can reduce the flow and supply pressure of the coolant.
The flow in the coolant in the drive components is subject to changes in cross-
section and direction. For that reason, there are friction and turning losses.
These losses show as the pressure drop Δp.
The pressure drop Δp
n
of the liquid-cooled motors is specified in the technical
data. It relates to the specified flow volume of water as coolant. If the flow vol-
ume is converted to a different temperature increase, the pressure drop must
be taken from the characteristic curve below.
Fig.9-24: Discharge-diagram for MSK motors
If a different coolant is used, a different coolant-specific flow dia-
gram is applicable.
Coolant
Pressure drop
Project Planning Manual | Rexroth IndraDyn S Electric Drives
and Controls
| Bosch Rexroth AG 171/194
Operating Conditions and Application Notes