Rolls-Royce Archives
         « Prev  Box Series  Next »        

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).
20 HP engine vibrations, detailing tests and findings related to the use of friction dampers.

Identifier  WestWitteringFiles\K\October1923\  Scan1
Date  1st October 1928
  
R.R. 493A (40 H) (SL 42 12-7-28). J.H., D.{John DeLooze - Company Secretary}

EXPERIMENTAL REPORT.

Expl. No. 634
REF: He7/I/DH.{D. Henderson - Showroom}10.28.

20 HP. - ENGINE VIBRATIONS.

We have been carrying out continuous tests in connection with the above. [strikethrough]Full standard engine mounting[/strikethrough] with friction dampers. We have carried out a number of further tests with this and also demonstrated it to EP.{G. Eric Platford - Chief Quality Engineer} On the cars we have tried this device on, so far, we still consider our original estimate of an improvement of 75% still holds good. We have proved it is not sensitive to the amount of friction. There is a very wide range which makes no apparent difference. The addition of friction appears to spread the vibration over a wider range at slightly higher speed but with much less amplitude.

Further tests in connection with this have proved that the addition of friction also reduces considerably the retard vibration which we get to a varying degree on the cars. The cause of the retard vibration must be entirely different to the vibration we get under full power which goes to prove that any vibration which is not self-contained in the engine, is liable to start a period on the frame.

We should say the percentage improvement in the retard vibration is equal to the percentage improvement in the forward vibration.

A most puzzling feature and one presenting much difficulty in investigating the above is the extraordinary difference found in various 20 HP. cars all made from the same drawings. In some cases such as 7-Coshawk-11, vibrations contd:-
  
  


Copyright Sustain 2025, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙