Relubrication intervals

The relubrication intervals tf for bearings with a rotating inner ring on horizontal shafts under normal and clean operating conditions can be obtained from diagram 1 as a function of:
  • the speed factor A multiplied by the relevant bearing factor bf where
    • A = n dm [mm/min]
    • bf = bearing factor dependent on bearing type and load conditions (table 1)
    • dm = bearing mean diameter [mm] = 0,5 (d + D)
    • n = rotational speed
  • the load ratio C/P
The relubrication interval tf is the estimated number of operating hours that a high-quality grease, consisting of mineral oil and a lithium base thickener, can perform adequately when the operating temperature is 70 °C (160 °F). When bearing operating conditions differ, the relubrication intervals (diagram 1) need to be adjusted (→ Adjustments of relubrication intervals due to operating conditions and bearing types).
If the speed factor A exceeds 70% of the recommended limits (table 1), verify the influence of the selected lubricant on the speed limits that are provided under Speeds and check whether the rotational speed is within these limits.
When using high performance greases, an extended relubrication interval and grease life may be possible.
For grease life of capped bearings, refer to the relevant product chapters.
For additional information, contact the SKF application engineering service.
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