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).
Letter discussing wheel torsional rates, damping, a proposed spider redesign, and a request for information on the Bentley Six.
| Identifier | ExFiles\Box 125\1\ scan0306 | |
| Date | 12th February 1936 guessed | |
| -4- Actually the torsional rate is 1,125,000 # inches per radian and in connection with this we use a very considerable amount of damping, the individual Belleville Springs being loaded to about 110# (Total load 650-700). This work followed early failures similar to yours and has resulted in a design which seems virtually unbreakable so long as proper damping is provided. We have many wheels on test - some with upwards of 50,000 miles and no failures to date. Should you still be interested in this development we would suggest a redesign of the spider with 6 spokes and 6 pads having the rim-mounting screws at each pad as are ours. Proportioning the spokes and rim as nearly like our drawing as possible would also be advisable. Our latest spider drawing is enclosed. We are at present using commercial SAE 1095 steel as it comes from the mill (Rockwell Hardness C-23 to 25). We are curious as to the RPM and frequency of the master torsional period of your Bentley Six. Mr. C. F.{Mr Friese} Arnold | ||