Dynamic axial load carrying capacity
Single row and single row full complement cylindrical roller bearings with flanges on both the inner and outer rings can support axial loads in addition to radial loads. Fa must not exceed 0,5 Fr.
The axial load carrying capacity is primarily determined by the ability of the sliding surfaces of the roller end / flange contact to support loads. Factors having the greatest effect on this ability are the lubricant, operating temperature and the ability of the bearing to dissipate heat.
The formulae below are valid for normal operating conditions, i.e.:
- ΔT ≈ 60 °C between the bearing operating and ambient temperature
- specific heat loss ≈ 0,5 mW/mm2
- viscosity ratio κ ≥ 2
-
misalignment ≤ 1 minute of arc
For misalignment > 1 minute of arc, contact the SKF application engineering service.
Depending on the bearing series and size, and the application conditions the permissible axial load is to be limited:
-
For constantly acting load to avoid any risk of flange damage:
-
bearings in the 2.. series
→ Fap max ≤ 0,0045 D1,5
-
bearings in other series
→ Fap max ≤ 0,0023 D1,7
-
bearings in the 2.. series
-
Surface of outside and bore diameter π B (D + d) ≤ 50 000 mm2
Perform calculations
-
Surface of outside and bore diameter π B (D + d) > 50 000 mm2
Perform calculations
-
Circulating oil applications
Perform calculations
-
For brief periods, provided it does not increase the bearing operating temperature > 5 °C temporarily
Fap brief ≤ 2 Fap
where
Fap = Fap, Fap oil or Fap maxDepending on the bearing size, load and speed, this “brief period” covers only several seconds or can last a few minutes. As rule of thumb it can be assumed that a “brief period” is the time it takes for the bearing to make 1 000 revolutions.
-
Occasional shock loads
Fap shock ≤ 3 Fap
where
Fap = Fap, Fap oil or Fap max
Symbols
| B | = | bearing width [mm] |
| C0
| = | basic static load rating [kN] (→ product tables) |
| d
| =
| bearing bore diameter [mm] |
| D
| =
| bearing outside diameter [mm] |
| ΔTS
| =
| temperature difference between incoming and outgoing oil flow [°C]
|
| Fa | = | axial load [kN] |
| Fap | =
| permissible axial load [kN]
|
| Fap brief
| =
| maximal axial load for brief periods [kN]
|
| Fap max | =
| maximal constantly acting axial load [kN]
|
| Fap oil
| =
| maximum permissible axial load in circulating oil applications [kN]
|
| Fap shock | =
| maximal occasional axial shock load [kN]
|
| Fr | = | radial load [kN] |
| k1 | = | lubrication factor
= 1,5 for oil lubrication = 1 for grease lubrication |
| k2 | = | lubrication factor
= 0,15 for oil lubrication = 0,1 for grease lubrication |
| n | = | rotational speed [r/min] |
| VS
| =
| amount of oil flow [l/min] |
