Calculation Procedure for
the Nominal Service Life
Many factors have an effect on the service life of a GLYCODUR® dry sliding bearing, including load, sliding velocity, operating temperature, roughness of the mating surface, etc. A calculation of the service life can therefore only be an approximation. The approximate values for the nominal service life determined by the equation below will be reached
by the majority of the bearings, and even exceeded in many cases. This has been confirmed by rig tests and historical results of actual operation.
For GLYCODUR sliding bearings the relation between the nominal service life and the influencing factors indicated results from the equation:
Gh= c1× c2× c3× c4× c5×
KM
(pv)n
Where:
Gh
nominal service life, operating hours
p
specific bearing load, MPa
v
sliding velocity, m/s
c1
load factor
c2
velocity factor
c3
temperature factor
c4
roughness factor
c5
load distribution factor
KM
constant depending on material and bearing type:
GLYCODUR
F
A
Bushings
480
1900
Thrust washers
300
1900
n
an exponent:
GLYCODUR
F
A
pv ≤ 1
1
1
pv ≥ 1
1
3
If the product pv of GLYCODUR® F bearings falls below the limit value of 0.025 at very low loads and/or sliding velocities, and of GLYCODUR® A
below the limit value of 0.1, then pv = 0.025 or pv = 0.1 have to be used in the service life equation.
Calculation procedure nominal service life -