Machines Without A Fan (Optional); Bearings Of Synchronous Machines - Siemens SIMOTICS A 1FU8 Operating Instructions Manual

3.3.3.2

Machines without a fan (optional)

Surface cooling by free convection: Cooling IC 410 in accordance with EN / IEC 60034-6
Image 3-2
Surface cooling by relative movement of cooling air: Type of cooling IC 418 in accordance with
EN / IEC 60034-6
Image 3-3
3.3.4

Bearings of synchronous machines

In order to support the machine shaft and maintain its position in the non-moving part of the
machine, only 2 rolling-contact bearings are used. One roller bearing performs the function
of a location bearing that transfers axial and radial forces from the rotating machine shaft to
the non-moving part of the machine. The second roller bearing is implemented as floating
and support bearing in order to allow thermal expansion inside the machine and transfer
radial forces.
Machines with degree of protection IP55 < 6000 rpm have deep-groove ball bearings with to
cover plates 2ZC3 version. The material of these covers must be resistant to temperatures
from -30 °C up to +150 e.g. by using polyacrylic rubber (ACM). For the ZC3 version with
cover plate, the cover plate is on the inside. Machines with degree of protection IP54 > 6000
rpm are equipped with special ball bearings.
The nominal (theoretical) service life of the bearings according to ISO 281 is at least 20,000
hours when the permissible radial/axial forces are utilized. However, the achievable useful
life of the bearings can be significantly longer in the case of lower forces (e.g. operation with
self-aligning couplings). Avoid rigid couplings.
Roller bearings with permanent lubrication are maintenance-free. For bearings that can be
relubricated, observe the data on the rating plate or lubricant plate.
1FU8
Operating Instructions, 02/2016, 5 610 70000 02 000
IC410
IC418
Description
3.3 Installation
25