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).
Material testing for a pin and bush assembly, discussing corrosion issues and recommending improvements.
| Identifier | ExFiles\Box 163\7\ img224 | |
| Date | 14th December 1933 | |
| - 2 - E.11/HP.14.12.33. and hard drawn bronze but owing to the way in which the pin is fixed in the casing these materials did not prove suitable for the fixing. Actually the recently completed 10,000 mile trial on the latest Bentley was performed with a chromium plated pin with a view to avoiding this corrosion. Delco's use some form of hard drawn gunmetal. We, therefore, consider that even if we have to make a slight modification to the pin fixing we can definitely overcome the corrosion trouble. Another point that arises is the fit of the bush on the pin and here we find there is a tendency to make this a very nice fit where it would be much better for it to have one or two thous. of slack, in which case the rust formation which occurred would probably have been broken down without causing a seizure of the bush. We are making further tests on the bush material subjecting it to heat etc. to determine the effect of this on the clearance, and also we are not satisfied with the bakelite at present used as the fracture does not indicate that it is a very good sample. We think that as an immediate measure of precaution all of these bushes should be eased out to give more clearance and that the pin should be lubricated. In the meantime we shall issue the necessary instructions for standardizing a corrosion resisting pin, and the necessary steps will follow in due course to adopt these improvements on all of our chassis. E.{Mr Elliott - Chief Engineer} | ||