The surface pressure p (N/mm²) of the sliding surface should not exceed the permissible pressure (see figure: capacity diagram).
p = 1,5 ⋅ F/A (parabolic)
A = d ⋅ b
F (N) = bearing load
d (mm) = Ø bearing bore hole
b (mm) = bearing length
A (mm²) = bearing surface
The allowed surface pressure is determined by the bearing material and the existing lubricant which should remain functional under load.
The allowed maximum load is 150N/mm².
Under load the maximum sliding velocity v should not exceed 60m/min.
L= F · v (thermic load capacity)
As modification of this formula the value p·v is used for the calculation of plain bearings.
The p- and v-values indicated in the capacity diagram are threshold values from which the frictional heat is carried out from the plain bearing by heat conduction and emission, in such an extent that no increase of heat in the sliding surface takes place. For special cases the customer should draw up a heat balance on the basis of the whole construction. If necessary solutions for heat dissipation should be considered during construction.
Parameters: frictional distance 500 metres, bearing bore hole Ra ≤ 1,2
mating material: St 1.4057, Ra ≤ 0,8, HB 240
sliding direction: rotating in continuous operation at room temperature