9.10.3
Bearing Lifetime
The bearing lifetime is an important criterion for the availability of motors.
When the lifetime is considered, the "mechanical lifetime" of bearing compo‐
nents and materials is differentiated from the "grease lifetime" of the bearing
lubricant.
If motors are operated within the limits specified for radial and axial loads, the
mechanical service life of the bearings is as follows:
Mechanical lifetime of bearings
L
10h
= 30000 operating hours
(calculated according to ISO 281, ed. 12/1990)
This applies to all MKE motors based on the following:
●
The permitted loads from the corresponding chapter "Technical Data"
are never exceeded.
●
The motor is operated under the permitted conditions for use and in the
permitted ambient temperature range of 0 °C to +40 °C.
Different loads may have the following effects:
●
Premature failure of the bearing due to increased wear or mechanical
damage.
●
Reduction of the grease lifetime leads to premature failure of the bear‐
ing.
●
Avoid exceeding the load limits.
Mechanical Bearing Lifetime in
case of Increased Radial Force
Otherwise, the service life of the bearing is reduced to:
L
10h
Bearing service life (according to ISO 281, Version 12/1990)
F
radial
Determined allowed radial force in N (newton)
F
radial_act
Actually acting radial force in N (newton)
Fig.9-18:
Calculating the bearing service life L10h if the allowed radial force
Fradial is exceeded
The actually acting radial force F
radial_act
may never be higher than
the maximum allowed radial force F
radial_max
.
Bosch Rexroth AG
DOK-MOTOR*-MKE*GEN2***-PR06-EN-P
Rexroth MKE Synchronous Motors for Potentially Explosive Areas acc. to ATEX and UL/CSA
88/135
Operating Conditions and Application Notes
LSA Control S.L. www.lsa-control.com comercial@lsa-control.com (+34) 960 62 43 01
