Motors-D81.1-complete-English-06-2020

© Siemens 2020
Introduction
Mechanical version
Bearings and lubrication
1 ■ Overview
Bearing lifetime (nominal lifetime)
The nominal bearing lifetime is defined according to standardized
calculation procedures (ISO 281) and is reached or even
exceeded for 90 % of the bearings when the motors are operated
in compliance with the data provided in the catalog.
Under average operating conditions, a lifetime (L 10h ) of
100 000 hours can be achieved.
Generally, the bearing lifetime is defined by the bearing size,
the bearing load, the operating conditions, the speed and the
grease lifetime. A bearing lifetime calculation is possible on
request.
Bearing system
The bearing lifetime of motors with horizontal mounting is 40 000
hours if there is no additional axial loading at the coupling output
and 20 000 hours when utilized according to the maximum admissible
load. This assumes that the motor is operated at 50 Hz.
The nominal bearing lifetime is reduced for converter operation
at higher frequencies.
In order to achieve the calculated lifetime in continuous operation,
the admissible vibration values (measured at bearing plate)
must be determined according to evaluation zones A and B stipulated
in ISO 10816. If higher vibration velocities occur in operation
(e.g. with option H02), special measures must be taken
(please inquire).
Due to their physical characteristics, variable-speed motors
have a different bearing lifetime under the same load conditions
– this relationship is linear, i.e. if the frequency increases by 20 %
from 50 Hz to 60 Hz, the lifetime decreases by 20 % from 20 000
to 16 000 hours under the load conditions specified in the catalog.
If the frequency falls by 20 % from 50 Hz to 40 Hz, under the
load conditions specified in the catalog, the lifetime rises by
20 % from 20 000 to 24 000 hours.
It should be observed that, for types of construction IM B6,
IM B7, IM B8, IM V5, and IM V6, the belt tension is only permitted
to act parallel to the mounting plane or towards the mounting
plane and the feet must be supported. Both feet must be secured
for foot-mounting types of construction.
In the basic bearing system, the floating bearing is situated at
the drive end (DE) and the located bearing is situated at the nondrive
end (NDE). For motors of the 1MB.553 series, the located
bearing DE is the standard version.
The bearing system is axially preloaded with a spring element at
the drive end (DE) to ensure smooth running of the motor without
play (see Fig. 1 in the diagrams of bearings on page 1/60).
From frame size 160 upwards, the located bearing is axially secured
at the non-drive end (NDE).
For the 1LE5 and 1MB5 motors of frame sizes 400 and 450, the
located bearing is situated at the drive end (DE) and the floating
bearing is situated at the non-drive end (NDE).
The bearing system on these motors is axially preloaded with a
spring element at the non-drive end (NDE) to ensure smooth running
of the motor without any play (see Figs. 6 and 7 under the
bearing diagrams on page 1/60).
Up to frame size 132, an additional axially-secured located
bearing can be supplied on the non-drive end (NDE) complete
with a retaining ring (see Fig. 2 under the diagrams of bearings
on page 1/60) or, for frame sizes 400 and 450, the located bearing
can be supplied at the non-drive end (NDE).
Order code L21
Depending on the specific installation conditions (axial forces,
cantilever forces and type of construction), testing of additional
measures for the bearing version is recommended. The located
bearing can also be supplied at the drive end (DE) (see Fig. 3
under the diagrams of bearings on page 1/60). A located bearing
at the drive end (DE) is recommended when gearing is installed,
for a shaft extension pointing downwards, or pumps and
fans are mounted directly on the motor shaft.
Order code L20
For increased cantilever forces (e.g. belt drives), reinforced
bearings can be used at the drive end (DE).
Versions with cylindrical roller bearings are not axially preloaded,
and must always operate under adequate radial loads
(it is not permissible that motors are operated on a test stand
without additional radial loads). The located bearing is at the
non-drive end (NDE). For 1MB.553, the located bearing is at the
drive-end (DE).
Not possible for motors of the 1MB.553 series.
Order code L22
1LE1, 1LE5, 1MB1, 1MB5, and 1PC1 motors can be supplied
with reinforced bearings (size range 03) at both ends.
In this case, the bearing plates are made of cast iron (standard
for series 1LE16 motors). Standard for motors of the 1MB.553
series from frame size 100 upwards.
Order code L25
A measuring nipple for SPM shock pulse measurement can be
mounted to check bearing vibration. The motors have an M8
tapped hole for each bearing plate and a measuring nipple with
a protective cap. If a second tapped hole is provided, it is fitted
with a sealing plug. Not possible for frame sizes < 100.
Order code Q01
Bearing selection for increased cantilever forces (see the Table
"Bearing selection for 1LE10, 1MB10, and 1PC10 motors – Bearings
for increased cantilever forces" on page 1/55) – for the maximum
axial load, see page 1/67 onwards.
Bearing insulation
To prevent damage caused by bearing currents, insulated
bearings can be supplied for frame sizes 225 to 355 – they
are recommended for motors from frame size 225 upwards. For
frame sizes 400 and 450 (for converter operation), the bearing
insulation is indispensable.
• L50 (DE bearing insulation) means NDE located bearing as
standard
• L51 (NDE bearing insulation) means DE located bearing as
standard
• L50 + L51 (insulated DE and NDE bearings) means NDE
located bearing as standard
• Combination of order codes L50 or L51 or L50 + L51 with L22
(bearing version for increased cantilever forces) means NDE
located bearing as standard.
According to IEC 60034-1-11, it is up to the user in the case of
DE bearing insulation (order code L50) + NDE bearing insulation
(order code L51) to ensure grounding of the rotor.
The rotor grounding can be implemented either in the system via
the coupled driven machine or in the motor via a grounding
brush.
The grounding brush (order code L52) must always be provided
when the driven machine is connected to the motor via an insulating
coupling or an insulating belt output shaft.
Permanent lubrication
On motors equipped with permanent lubrication, the bearing
grease lifetime is matched to the bearing lifetime. This can, however,
only be achieved if the motor is operated in accordance
with the catalog specifications.
In the basic version, the motors have permanent lubrication.
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