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).
Extract detailing the thermal expansion and failure analysis of a rubber cylinder joint.
| Identifier | ExFiles\Box 65\4\ scan0107 | |
| Date | 6th November 1928 guessed | |
| Extract from experimental report :- RUBBER CYLINDER JOINT. Expansion of cyl. block 25 X 10-6 approx. or .000026 " " rubber ring 4.7 X 10-5 " " .000047 Therefore the excess expansion of the rubber ring over the aluminium block for a temperature rise of 85°C is only .010" approx. on the diameter. As far as we can make out, the present dimensions of the radii at the back of the groove accomm- odation for the .013 initial compression on the dia. and about .005 expansion, so that actually there remains only about .005 expansion on the dia. which has to be accommodated by compressing the rubber as opposed to distorting it into some other position. Additionally, the gap between the liner and cylinder casting increases to .003 at 100°C so that the rubber can flow through this should it be put in tightly. This, we think explains why we could not break a thin ring with 150°C rubber temperature rise. Therefore we feel that the cyl. block failure cannot be attributed to this rubber joint, and that therefore the original dimensions allocated to this rubber by experiment should be adhered to. ------------- | ||