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).
Revised design for the Goshawk 11 spring drive to overcome issues found during testing.
| Identifier | ExFiles\Box 79\3\ scan0152 | |
| Date | 2nd June 1923 | |
| To BY.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c. to CJ. c. to Hs.{Lord Ernest Hives - Chair} c. to EP.{G. Eric Platford - Chief Quality Engineer} X4222 E3/M2.6.23. GOSHAWK 11. SPRING DRIVE X.4222. We send herewith drawing LeC.1727. shewing the above revised with a view to overcoming the troubles experienced during the experimental testing of E.52565. You will notice that the friction plate and spring drive are made in one piece and mounted on a longer taper than was used before for the friction plate. It is essential that this piece shall be tight on its taper and that this tightness shall not be balked in any way by the taper hub or securing nut being stopped up against shoulders or other features. We think the revised construction of the spring drive makes the job less likely to be wrong because the complete unit is now placed in between the friction surfaces and depends on fewer dimensions for the important features involved. It should also be more easily seen whether the assembly is correct or not. We do not think it is possible to get the friction plate sufficiently tight by screwing up the ring nut provided, because the efficiency of this nut is only 3%. It will be necessary either to tighten the friction plate on its taper independently by means of a central bolt or to assist the ring nut by means of pressure from a central bolt during tightening as explained on the drawing. We have not altered the crankshaft beyond adding slightly to the length of the taper which carries the spring drive drum. This extra piece of length on the taper is accommodated by counterboring the crankshaft nut. This alteration does contd:- | ||