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).
The conditions under which servo gear rattling occurs on Chassis 9-G-111.

Identifier  ExFiles\Box 4\9\  09-page132
Date  27th August 1925
  
EXPERIMENTAL REPORT
Expl. No
REF GWH{George W. Hancock - Head Chateauroux}2/Crn27.8.25.
Hotel de France,
Chateauroux, Indre,
France.
GWH{George W. Hancock - Head Chateauroux}2/Crn27.8.25.
To Hs.{Lord Ernest Hives - Chair}
From G.W.Hancock.
CHASSIS 9-G-111.
Your letter dated the 25th.inst. received.
Re. servo gear rattling, the tests carried out up to the present date, give us the following results :-
Acceleration on full throttle.
The periods are at 12 to 18 m.p.h., noticed again at 20 m.p.h., start again at 26 to 29 m.p.h., the max. is at 26 to 29 m.p.h., this being the bad period of which we are complaining. The periods again come on between 30 and 32 m.p.h., approx. We have noticed one at slightly higher speeds, but this is not definite.
The amount of amplitude of servo gear rattles is definitely increased and decreased per load applied to car. One can by accelerating very slowly on a level road, go through the periods with almost entire absence of rattles. The rattles increase xxxxxxxxxxxxxxx per ratio as the throttle opening is increased. The rattle is the most pronounced when car is travelling on a slight incline, and throttle is opened wide at the critical speed. The servo gear rattles also are of less amplitude when the box is cold. Also, the periods are approx. 3 to 4 miles per hour slower, viz: the period we state at 29 m.p.h. when the box is cold the max. is 26 m.p.h. There is a difference between getting the box hot on a cool day, and on a hot day.
Shut throttle conditions.
Car driving engine down-hill, no periods from servo gears are noticeable. Retard, with shut throttle, on level, there is a slight period between 47 to 40 m.p.h. With gear in neutral, there are no periods.
Engine shut off.
Engine shut off, and throttle closed, the period is the same as with shut throttle condition. With engine shut off and throttle open, there is only a very slight rattle, between the speeds of 47 to 40 m.p.h.
contd:-
  
  


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