Page 404 - Rollingbearings

3 Angular contact ball bearings
Temperature Permissible speed

limits
The speed ratings in the product tables
indicate:
The permissible operating temperature for
angular contact ball bearings can be limited • the reference speed, which enables a
by: quick assessment of the speed capabilities
from a thermal frame of reference
3 • the dimensional stability of the bearing • the limiting speed, which is a mechanical
rings and balls
limit that should not be exceeded unless
• the cage the bearing design and the application are
• the seals adapted for higher speeds
• the lubricant
For additional information, refer to Operating
Where temperatures outside the permissible temperature and speed, page 130
range are expected, contact SKF SKF recommends oil lubrication for bear-
ings with a ring centred cage (designation
Bearing rings and balls sufix MA or PHAS). When these bearings are
grease lubricated, the nd value is limited to
m
The bearings are heat stabilized up to at 250 000 mm/min
least 150 °C (300 °F)
where
Cages d = bearing mean diameter [mm]
m
= 0,5 (d + D)
Steel, brass or PEEK cages can be used at the n = rotational speed [r/min]
same operating temperatures as the bearing
rings and balls For temperature limits of Bearing pairs
cages made of other polymer materials,
refer to Polymer cages, page 188 For bearings arranged in pairs, the limiting
speed should be reduced to approximately
Seals 80% of the value quoted for a single bearing
The permissible operating temperature for
NBR seals is –40 to +100 °C (–40 to
+210 °F) Temperatures up to 120 °C
(250 °F) can be tolerated for brief periods
Typically, temperature peaks are at the
seal lip

Fig. 11
Lubricants
Proper adjustments
Temperature limits for greases used in
sealed SKF angular contact ball bearings are
provided in table 2, page 389 For tempera-
ture limits of other SKF greases, refer to
Selecting a suitable SKF grease, page 116
When using lubricants not supplied by
SKF, temperature limits should be evaluated
according to the SKF trafic light concept
(page 117)

Single bearing, Bearing set,
face-to-face back-to-back

402