Page 512 - Rollingbearings

6 Cylindrical roller bearings

Dynamic axial load carrying capacity

Cylindrical roller bearings with langes on both the inner and outer The formulae below are valid for normal operating conditions:
rings can support, in addition to radial loads, axial loads up to:
• ΔT ≈ 60 °C between the bearing operating and ambient
• F ≤ 0,25 F for double row full complement bearings temperature
a
r
• F ≤ 0,5 F for other design bearings • speciic heat loss ≈ 0,5 mW/mm 2
r
a

• viscosity ratio κ ≥ 2
The axial load carrying capacity is determined by the lubrication • misalignment ≤ 1 minute of arc
condition, operating temperature and heat dissipation at the roller For misalignment > 1 minute of arc, contact the SKF appli-
end / lange contact cation engineering service

Permissible axial loads

Conditions Mechanical limitations Thermal limitations

6 Continuous Bearings in the 2‥ series Circulating oil lubrication Symbols
F ap max ≤ 0,0045 D 1,5
15 × 10 4 k ∆T V˙ s A reference surface [mm 2 ]
1
s
F ap oil = F + ————————–
ap
Bearings in other series n (d + D) = π B (D + d)
F ap max ≤ 0,0023 D 1,7 B bearing width [mm]
C basic static load rating [kN]
0
High-capacity bearings Other lubrication (product tables, page 516)
F ap max ≤ 0,0035 D 1,7 • Reference surface A ≤ 50 000 mm 2 d bearing bore diameter [mm]
D bearing outside diameter [mm]
k C 10 4 ΔT temperature difference between
0
1
F = ———— – k F r S
2
ap
n (d + D) incoming and outgoing oil low [°C]
F a axial load [kN]
F ap permissible axial load [kN]
• Reference surface A > 50 000 mm 2 F ap brief maximal axial load for brief periods
[kN]
7,5 k C 2/3 10 4
1
0
F = ——————— – k F r F ap max maximal constantly acting axial
2
ap
n (d + D)
load [kN]
F ap oil maximum permissible axial load in
circulating oil applications [kN]
F ap peak maximal occasional axial peak load
Brief periods F ap brief ≤ 2 (F , F ap oil , F ap max ) [kN]
ap
• provided it does not increase the bearing operating temperature F r radial load [kN]
> 5 °C temporarily k , k 2 lubrication factors (table 6)
1
• “brief period” is the approximate time for 1 000 revolutions to take n rotational speed [r/min]
place V̇ amount of oil low [l/min]
S
Occasional High-capacity bearings
peak loads F ap peak ≤ 0,0085 D 1,7
Other bearings
F ap peak ≤ 3 (F , F ap oil , F ap max )
ap

510