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).
Investigating mass vibration on a car at 20 miles per hour and requesting an experimental report.
| Identifier | ExFiles\Box 3\1\ 01-page086 | |
| Date | 26th February 1913 | |
| From F.H.R. Copies sent to: Mr. Johnson, Mr. Northey, Mr. Wormald, Mr. Barrington. R18/B26213. [Handwritten in left margin:] Wormald Put on list of jobs for P <u>With reference to the 20 miles per hour on Mr. Northey's car and on all other cars.</u> I have received a sheet from Mr. Barrington to say that this was a mass vibration and no further explanation is suggested. This matter was brought up when we fitted this particular engine with light pistonsand light connecting rods, because I believe that at the time it was thought that it was definitely caused by some remaining crank-shaft vibration. This idea has now, I think, been exploded and we now distinctly say that there are no connecting rod vibrations whatever on our engines. But we have left 2 vibrations, one called a mass vibration of the engine and the other a vibration of the back axle, probably owing to the imperfection of the bevel drive. The latter of these can be definitely cured by retaining the friction damped spring coupling and removing the footbrake drum. The cause of the mass vibration of the engine is, however, so far a mystery to me. What is really my own impression is that the vibration is caused by a reaction of the explosion in the cylinders, because on closing the throttle it disappears. I wish, therefore, that this vibration shall be investigated to determine what are the parts that move. Is it the whole of the engine and the front end of the frame vibrating torsionally because from the nature of my suggestions contained herein it cannot be the mass of the engine moving in a vertical or horizontal direction as there would be no such tendency unless the parts were out of balance, which out of balance would have to be quite serious at so slow a speed. I shall be pleased to receive a report on any experiment which may make this matter clear. F.H.R. [Handwritten signature:] h/w Johnson [Handwritten:] X181/A [Stamped:] D 11 MAR 1913 RECEIVED | ||