High Precision Ball Bearings - Kraftmek

1.1. Universal matching with axial play
Symbol DUA
The bearings are prepared in such a way that with inner
and outer rings locked together in the DF or DB arrangement,
a certain axial play is included. As the magnitude
of the axial play depends on the operating conditions,
the axial play must be specified for each individual
application. For example with axial play 40 to 60 microns,
the symbol reads DUA 40.60.
1.2. Universal matching without axial play
Symbol DUO
The bearings are prepared in such a way that with inner
and outer rings locked together in DF or DB arrangement,
there is no axial play in the bearing set.
1.3. Universal matching with preload
Symbol DUV
When a rigid bearing arrangement, free from play, is
required, a matching of bearings with preload is used.
Bearings matched with preload have the advantage that
under the effect of an external load only a small elastic
deformation takes place, compared to unmatched
bearing pairs or single bearings. The bearings are
prepared in a way that with inner and outer rings locked
together they are under the effect of a preload. The
preload has to be considered as an additional axial load
in the life time calculation.
The preload of DUV matched bearings is 2% of the
dynamic load rating, however the max is 300N. A preload
can be specified to suit your requirements.
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