REXROTH IndraDyn A Series, Project Planning Manual

Page: 187 / 220

Rexroth IndraDyn A Application Notes
9-31
If the duration of use of the motor is limited by a short grease lifetime, the
duration of use can be increased by using the standard bearing in place of
the reinforced bearing in exceptional cases. The grease lifetime therefore
increases, however, the increased loading of the standard bearing
reduces the available mechanical lifetime to below 30,000 operating
hours.
⇒
This requires subsequent calculation of the bearing lifetime by
Rexroth. In this case, contact one of our branch offices and explain
your application with all relevant application data (load cycle, axial and
radial loads, speeds, etc.).
The calculation and dimensioning of the bearing is based on
standard DIN ISO 281.
The available grease lifetime of the deep-groove ball bearing and the
cylindrical roller bearing in IndraDyn A motors is shown in the following
diagrams.
The diagram contains the various characteristic curves, depending on the
type of bearing, i.e. standard, high-speed or reinforced bearings, as well
as the bearing for the attachment of a coupling.
5
10
20
6
7
8
9
15
25
30
0,5 1 2 3 4 6 5 7 8 9 10
x 103
t f
[h]
x 10
3
nm [min-1]
1
Fettgebrauchsdauer_MAx100.EPS
t
f
: Grease lifetime (without reduction factor)
(1): Standard bearing, high-speed bearing and bearing for coupling
attachment
n
m
: mean speed (for the calculation, refer to Fig. 9-26)
Fig. 9-37: Grease lifetime, size 100
Grease Lifetime, Motor-frame
size 100