Index.htm Brgs130.htm

CONCLUSIONS

1. The wear (in terms of change of internal bearing diameter) which occurs in a wood/steel bearing running below a certain temperature limit is directly proportional to radial loading (F), shaft angular velocity (N) , and time period (t), and is indirectly proportional to bearing width (L).
2. For any timber type and lubrication treatment a value of wear modulus or wear coefficient can be determined by experiment
3. Knowledge of this wear modulus enables estimation of the useful bearing lifetime before repair or replacement, provided that the bearing is not operating at temperatures at which more rapid wear occurs.

 

4. Friction coefficient values for the 7 timbers tested were fairly constant at average values of 0.,35 for unlubricated bearings and 0.15 for oil-lubricated bearings.
5. Wear tests on the 7 tiumbers running under greased conditions showed only small variations in wear moduli.
6. Wear tests on the 7 timbers running dry showed large variations in wear moduli. Three wood types - African Blackwood, Msaraka and East African Afrormosia gave low wear rates under dry conditions. But these low wear rates for the 3 best woods were still 2.0 to 2.5 times faster than wear rates for the same woods when lubricated.
7. Continuous oiling gave the lowest wear rates, followed by greasing, and then by impregnation; dry running of course gave the highest wear rates.