certific at e - NOC international

Assembling roller bearings
Design of the bearing
Every shaft or axes that must be rotated against the housings and other components of the machine (or the subassembly)
and has to overcome forces in doing so must be supported on at least two roller bearings.
The roller bearings are arranged as:
Fixed movable bearing
The fixed bearing cannot be axially moved in
any way, it is firmly clamped both on the shaft
as well as in the housing. The movable bearing
can either move by itself because of design (cylindrical
roller bearing NU, N) or because the
axial displacement takes place in the housing
seat with a suitable fit.
Angled bearings
Axially engaged bearings, e. g. single row angular
contact ball bearing or tapered roller
bearings, ensure a very good axial guiding
accuracy of the shaft, e. g. of the working
spindle of a machine tool, if the bearing pair
has been pretensioned. There are many different
arrangements of the individual bearings,
mostly in O - or X-arrangement or in a combination
of these, if more than two individual
bearings determine the bearing point. If two
axially loaded roller bearings are mounted in
the same loading direction, this is referred to
as a tandem arrangement.
In the calculation of the bearing forces, the axially
acting pretension forces must be additionally
taken into consideration as inner forces.
Floating bearing
The floating bearing is the simplest arrangement
of roller bearings from a design as well
as economic standpoint. If the demands for
guiding accuracy are not very high, deep groove
ball bearings are mostly used. In the housings,
there is sufficient clearance in the axial
direction, so that e. g. heat elongation of the
shaft can be compensated without any problems
and almost in a zero-force manner, without
this resulting in an additional load inside
the roller bearings.
KRW 133