From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Bearing failure caused by oil choking from accumulated brush dust, suggesting sealed bearings as a better solution.
Identifier | ExFiles\Box 166\1\ img130 | |
Date | 21th April 1939 | |
-2- Rm{William Robotham - Chief Engineer}/RC.{R. Childs}1/JH.21.4.39. By supplying oil to the oiler on the outside of the bracket, it was ascertained that the hole through the bracket to the inside was not choked up. It was found that in spite of the accumulated brush dust, the oil flowed over the top of it and eventually reached the bearing, providing enough was forced in at the oiler. It appears then that failure was due to partial absorption by brush dust of the oil on its way to the bearing and absorption of the remainder by the bust in the bearing, the dust in the bearing eventually choking it. From the above it is evident that a better performance could be obtained if the bearing were more effectively sealed, or if a sealed type of bearing were used. We have experienced trouble of this kind on one or two dynamos, and previous evidence pointed to the oil hole from lubricator to bearing, being too small, becoming completely choked and thus preventing oil from getting to the bearing. The above experiment suggests that the choking of the hole is only a secondary fault caused by the outer race turning in the aluminium housing after seizure of the bearing, due to the presence of brush dust. A further test will be carried out on the same lines, but with a greased packed bearing. Rm{William Robotham - Chief Engineer}/RC.{R. Childs} | ||