Lubrication and maintenance
Grease fills
SKF ConCentra ball bearings and SKF
ConCentra ball bearing units are filled with a
high-quality, long-lasting grease that has a
mineral oil based and a lithium-calcium
thickener.
The grease, which has a consistency of 2
on the NLGI scale, is extremely water resist-
ant and will provide long service life even
under heavy loads. The properties of this
grease are listed in table 1.
Grease life
Grease life for SKF ConCentra ball bearings
should be estimated according to the proce-
dure described in this section. The grease
life is presented as L10, i.e. the time period
at the end of which 90% of the bearings are
still reliably lubricated. The grease life can be
obtained from the diagram 1 depending on
the operating temperature, the bearing
mean diameter dm († table 2) and the ro-
tational speed n.
The grease life is valid under the following
operating conditions:
horizontal shafts•
very light to moderate loads (P ≤ 0,05 C)•
stationary machine•
low vibration levels•
If operating conditions differ, the grease life
obtained from the diagrams has to be
adjusted:
For vertical shafts, use 50% of the value •
from the diagram
For heavier loads (P > 0,05 C), use the •
reduction factor listed in table 3
The values for adjusting the grease life are
estimates. Vibration can have a negative
influence on grease life. The extent cannot
be quantified, and the influence increases
with increasing operating temperature. For
additional information contact the SKF
application engineering service.
Relubrication
SKF ConCentra ball bearings do not need
relubrication when the grease life exceeds
the bearing life († Selection of a bearing
unit size, page 8).
Relubrication can enable the bearing to
realize extended service life in one of the
following cases:
The bearings are exposed to high humidity •
or severe contamination
The bearings accommodate heavy loads•
The bearings operate at high speeds or at •
temperatures above 55 °C (130 °F) for
extended periods
The bearings are subjected to high vibra-•
tion levels
Table 2
Bearing mean diameter d
m
Bearing size
1)
–
mm
05 39
06 46
07 53,5
08 60
09 65
10 70
11 77,5
12 85
1)
For Example: size 07 includes all bearings based on a
Y 207 bearing, such as YSP 207-104 BS-2F,
YSP 207-106 BS-2F, YSP 207 BS-2F,
YSP 207-107 BS-2F
Table 1
Lubricating greases
Technical specification Grease fills in standard Y-bearings,
standard Y-bearing units
Thickener Lithium-calcium soap
Base oil Mineral oil
Colour Yellowish brown
Temperature range (°C) (continuous operation) -30 to +120
1)
Kinematic viscosity (mm
2
/s) of base oil at 40 °C/100 °C 190/15
Consistency (to NLGI scale) 2
Other Long life grease
1)
The temperature range for reliable operation in accordance with SKF traffic light concept is between 10 and 120 °C
15
B
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