Page 258 - Rollingbearings

1 Deep groove ball bearings

1 Temperature Lubricants
Temperature limits for greases used in SKF
limits deep groove ball bearings capped on both
sides are provided in table 3, page 245 For
temperature limits of other SKF greases,
The permissible operating temperature for refer to Selecting a suitable SKF grease,
deep groove ball bearings can be limited by: page 116
When using lubricants not supplied by
• the dimensional stability of the bearing SKF, temperature limits should be evaluated
rings and balls according to the SKF trafic light concept
• the cage (page 117)
• the seals
• the lubricant

Where temperatures outside the permissible Permissible speed
range are expected, contact SKF.

Bearing rings and balls The speed ratings in the product table
indicate:
SKF deep groove ball bearings are heat sta-
bilized up to at least 120 °C (250 °F). • the reference speed, which enables a
quick assessment of the speed capabilities
Cages from a thermal frame of reference
• the limiting speed, which is a mechanical
Steel, stainless steel, brass or PEEK cages limit that should not be exceeded unless
can be used at the same operating tempera- the bearing design and the application are
tures as the bearing rings and balls. For adapted for higher speeds
temperature limits of cages made of other
polymer materials, refer to Polymer cages, For additional information, refer to
page 188. Operating temperature and speed, page 130

Seals SKF recommends oil lubrication for bearings
with a ring centred cage (designation sufix
The permissible operating temperature for MA or MB) When these bearings are grease
seals depends on the seal material: lubricated, the nd value is limited to
m
250 000 mm/min
• NBR: –40 to +100 °C (–40 to +210 °F)
Temperatures up to 120 °C (250 °F) can where
be tolerated for brief periods.
• FKM: –30 to +200 °C (–20 to +390 °F) d = bearing mean diameter [mm]
m
Temperatures up to 230 °C (445 °F) can = 0,5 (d + D)
be tolerated for brief periods n = rotational speed [r/min]

Typically, temperature peaks are at the seal
lip

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