Dynamic axial load carrying capacity

Double row and double row full complement cylindrical roller bearings with flanges on both the inner and outer rings can support axial loads up to Fa ≤ 0,25 Fr in addition to radial loads.
The axial load carrying capacity is determined by the lubrication condition, operating temperature and heat dissipation at the roller end / flange contact.
The formulae below are valid for normal operating conditions:
  • ΔT ≈ 60 °C between the bearing operating and ambient temperature
  • specific heat loss ≈ 0,5 mW/mm2
  • viscosity ratio κ ≥ 2

Permissible axial loads

ConditionsMechanical limitationsThermal limitations
Continuous
Fap max ≤ 0,0023 D1,7
  • Reference surface A ≤ 50 000 mm2
  • Reference surface A > 50 000 mm2
  • Increased permissible axial load when heat is removed by circulating oil lubrication
Brief periods

Fap brief ≤ 2 (Fap, Fap oil, Fap max)

  • provided it does not increase the bearing operating temperature > 5 °C temporarily
  • “brief period” is the approximate time for 1 000 revolutions to take place

Occasional peak loadsFap peak ≤ 3 (Fap, Fap oil, Fap max)

Symbols

Areference surface [mm2]
= π B (D + d)
Bbearing width [mm]
C0
basic static load rating [kN] (→ product table)
d
bearing bore diameter [mm]
D
bearing outside diameter [mm]
ΔTS
temperature difference between incoming and outgoing oil flow [°C]
Fappermissible axial load [kN]
Fap brief
permissible axial load for brief periods [kN]
Fap maxmaximum permissible axial load set by mechanical limitations [kN]
Fap oil
permissible axial load in circulating oil applications [kN]
Fap peakpermissible axial peak load [kN]
Frradial load [kN]
k1lubrication factor
= 0,35 for oil lubrication
= 0,2 for grease lubrication
k2lubrication factor
= 0,1 for oil lubrication
= 0,06 for grease lubrication
nrotational speed [r/min]
VS
amount of oil flow [l/min]
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