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).
Technical memorandum discussing the driving radius of a V-belt for the engine fan and experimental belt ratios.
| Identifier | ExFiles\Box 75\3\ scan0077 | |
| Date | 23th March 1925 | |
| X1017 EFC. Hs.{Lord Ernest Hives - Chair} BY/SS{S. Smith} BY18/H.{Arthur M. Hanbury - Head Complaints} 23.3.25. FAN. Referring to EFC4/T. 20.3.25. we have always reckoned that the driving radius of a "V" belt is approximately 1/3 of the vertical distance the belt is in contact with the "V", reckoned from the top edge of the contact. Your memo corrects us in this, in as much as you give us 1/4 of the way down instead of 1/3. With reference to the engine fan, we have of course got to put something on order. We have already issued instructions for the Fan.No.15 which was handed to us with a speed ratio of 1.2 We will issue experimentally two further ratios, namely, 1.05 to 1 and 1.1 to 1, but we wish to make it clear that as we have got to have something on order in accordance with CJ's instructions, what we have done is to order Fan.No.15 to 1.2 to 1 ratio, for 300 chassis. Will Mr.Shelton kindly arrange to issue the new belt ratios experimentally. If and when Hs.{Lord Ernest Hives - Chair} finds an advantage in one or the other of the fans, we will be prepared to consider this in regard to making changes. BY.{R.W. Bailey - Chief Engineer} By | ||