SKF MicroDosage System Assembly Instructions Manual page 39

4. Assembly
The lubricant ducts inside a spindle and to the
bearing lubrication points should meet the fol-
lowing criteria:
o As short as possible
o Diameter of 0.5 mm to max. 1.0 mm
The way the lubricant is fed to the bearing de-
pends on the bearing type and the bearing
assembly's design features. Figures 2 to 4 be-
low provide examples of the lubricant feeding.
In case of single-row rolling bearings, it is
possible for the lubricant to be introduced into
the rolling bearing from the side. To do so, a
needle with an internal diameter of approx.
0.5 mm should be introduced as deep as pos-
sible into the rolling bearing at the level of the
its inner ring. This penetrates the air vortex
generated by high-speed bearings and reduc-
es the impact on lubricant distribution.
If using rolling bearings that exert pumping
force in one direction (e.g. angular contact
bearings), the lubricant must be fed in the di-
rection of pull. In case of double-row cylindrical
roller bearings, the lubricant should be intro-
duced into the rolling bearing from both sides
at the level of the outer ring raceway. It is also
possible to feed the lubricant via a borehole
on the rolling bearing's running surface locat-
ed in the bearing's outer ring (see Figure 3).
In this case, it must be assured that the lubri-
cant is not introduced into the pressure zone
of the rolling bearing between the rolling ele-
ment and the bearing ring.
There must be only one borehole in the outer
ring if the lubricant is fed via a borehole in the
outer ring and the outer ring is equipped with
a groove through which the lubricant reaches
the borehole.
Additionally, the groove must be completely
primed during installation.
Further boreholes would lead to drainage of
the lubricant-filled outer ring groove,which
could result in insufficient lubrication of the
bearing.
Page 39
Lubricant feeding for vertical and horizontal
mounting position and rotating inner ring, Fig. 2
Housing Lubricant feed Distribution ring
Needle/
capillary
Spacer ring
Observe the instructions from the
bearing manufacturer regarding the
bearings to be used; consult with the
bearing manufacturer if necessary.
EN
Outer ring
Cage
Inner ring
Shaft