Nominal Service Life Calculation Procedure for GLYCODUR® F under Dry Conditions
Many factors have an effect on the service life of a GLYCODUR® dry sliding bearing, e.g. load, sliding velocity, operating temperature, roughness of the mating surface etc.
A calculation of the service life [Online Service Life Calculation - click here] 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:
| Where | |
|---|---|
| Gh | nominal service life, operating hours |
| p | specific bearing load, MPa [more info] |
| v | sliding velocity, m/s |
| c1 | load factor [more info] |
| c2 | velocity factor [more info] |
| c3 | temperature factor [more info] |
| c4 | roughness factor [more info] |
| c5 | load distribution factor [more info] |
Specific surface load p
The specific surface load can be determined by dividing the total bearing load (shaft weight plus applied load) by the bearing projected area (inner diameter × width).
| Where | |
|---|---|
| p | specific load, MPa |
| F | dynamic bearing load, N |
| C | dynamic load capacity, N |
Specific load characteristic value
K = 80 MPa for GLYCODUR® F
K = 120 MPa for GLYCODUR® A
The factor K mainly considers, that the bearing diameter and the operating clearance are increasing with increasing service life, thus reducing the contact surface between bearing and shaft.