Page 1050 - Rollingbearings

21 Hybrid bearings
Loads Bearing rings Permissible speed
The rings of SKF hybrid bearings are heat
stabilized up to at least:
For recommendations about minimum load, The speed ratings in the product tables
axial load carrying capacity and equivalent • 120 °C (250 °F) for basic design hybrid (Hybrid deep groove ball bearings,
bearing loads, refer to Loads of the relevant deep groove ball bearings page 1050 and Hybrid cylindrical roller
standard bearing: • 150 °C (300 °F) for hybrid cylindrical roller bearings, page 1056) indicate:
bearings and XL hybrid deep groove ball
• Deep groove ball bearings, page 254 bearings • the reference speed, which enables a
• Cylindrical roller bearings, page 509 quick assessment of the speed capabilities
On request, SKF can supply hybrid bearings from a thermal frame of reference
The required hybrid bearing speciic values with rings stabilized for operating tempera- • the limiting speed, which is a mechanical
and factors are listed in the relevant product tures up to 300 °C (570 °F) limit that should not be exceeded unless
tables: the bearing design and the application are
Cages adapted for higher speeds
• Hybrid deep groove ball bearings,
page 1050 Steel, brass or PEEK cages can be used at For additional information, refer to Operating
– basic static load rating C 0 the same operating temperatures as the temperature and speed, page 129
– calculation factors f and k r bearing rings of standard hybrid bearings SKF recommends oil lubrication for bear-
0
• Hybrid cylindrical roller bearings, For temperature limits of other polymer ings with a ring centred cage (designation
page 1056 cages, refer to Polymer cages, page 188 sufix ML) When these bearings are grease
– calculation factor k r lubricated, the nd value is limited to
m
– reference speed Seals ≤ 250 000 mm/min
The permissible operating temperature for where
seals depends on the seal material: d = bearing mean diameter [mm]
m
Axial preload = 0,5 (d + D)
• NBR: –40 to +100 °C (–40 to +210 °F) n = rotational speed [r/min]
To provide low noise and high-speed oper- Temperatures up to 120 °C (250 °F) can
ation, typically an axial preload to a bearing be tolerated for brief periods
arrangement comprising two hybrid deep • FKM: –30 to +200 °C (–20 to +390 °F)
groove ball bearings is applied Axial preload Temperatures up to 230 °C (445 °F) can
can be applied with spring washers, as be tolerated for brief periods
described under Preloading with springs,
page 186 Typically, temperature peaks are at the seal
21 lip

Lubricants
Temperature Temperature limits for the grease used in

limits sealed SKF hybrid deep groove ball bearings
are provided in table 3, page 116 For tem-
perature limits of other SKF greases, refer to
The permissible operating temperature for Selecting a suitable SKF grease, page 116
hybrid bearings can be limited by: When using lubricants not supplied by
SKF, temperature limits should be evaluated
• the dimensional stability of the bearing according to the SKF trafic light concept
rings (page 117)
• the cage
• the seals
• the lubricant

Where temperatures outside the permissible
range are expected, contact SKF

1048