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).
Outlining the features of a proposed balanced crankshaft for a 25 HP engine.
| Identifier | ExFiles\Box 103\3\ scan0010 | |
| Date | 18th December 1930 | |
| X5010. R.{Sir Henry Royce} c. Sg.{Arthur F. Sidgreaves - MD} wor.{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} c. Hs.{Lord Ernest Hives - Chair} E.{Mr Elliott - Chief Engineer} RECEIVED 18 DEC 1930 H Rgl/ME.18.12.30. BALANCED CRANK FOR 25 H.P. Following the discussion with regard to the above when 'Rm{William Robotham - Chief Engineer}' and I visited you at West WitteringHenry Royce's home town on the 10th, Ten. has made some investigation into the matter on the lines set out in your note R.I/M.11.12.30. I am sending you along a sketch embodying the following features:- (1) Balance weights on 1, 3, 4 & 6 cranks, to balance 3 cylinder couple. (2) Crankpins and webs only balanced, not big ends. (3) Balance weights are made as compact as possible, so as to have a large mass at a short radius. The inertia, M r^2, is thus a minimum for a given value of M r (balance). The tendency of the balance weights to lower the torsional period is then a minimum. (4) Reduced thickness webs with increased width, and longer bearings, as in aero practice. (5) As shown it is drawn to suit existing engines, without waiting for increase of stroke. We believe for experiment it could be got into the existing crankcase, if we were to omit the bearing shells from the big ends and whitemetal direct. (6) Estimated torsional period probably over 5000 R.P.M. We suggest we should try this shaft in an existing engine, with a view to gaining experience. Rg.{Mr Rowledge} | ||