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).
Issues with hard spots on Marles steering cams for the Phantom III & 25/30 HP models and discussions with the Adamant Company.

Identifier  ExFiles\Box 106\3\  scan0427
Date  2nd December 1936
  
F.J.H.
t E 250
By's suggestion seems a very reasonable one.
Pass
BHS/M 2.12.36.

MARLES STEERING CAMS - PHANTOM III & 25/30 H.P.

Last week the Works drew my attention to the fact that whilst during the last six weeks we have been receiving cams which had no tight places on the thread apart from the central position which we set tight purposely, on recent deliveries there were two hard spots so that it was not possible to set the cam tight on the centre as it would then have been impossible to pass the hard spots approximately 40° - 50° on each side of the centre position.

Knowing that it was possible there might be something in the cam design itself which caused this trouble I made a layout on the drawing board, and found that if the cam is accurately produced there are two interference points, one on each side of the central position, which would prevent us feeding the roller to take up the slack in the central position.

In view of this I arranged to visit the Adamant Company's Works on Monday, when Commander Matravers confirmed the fact that the design did involve two hard spots, but he pointed out that the Adamant Company had never agreed to the scheme we were using of pre-loading the gear by pressing the follower roller tightly into gear on the central position of the cam, and took the strongest exception to this practice.

The position up to the present has been that we pre-load in three ways :-

(a) On the roller bearings carrying the cam by pinching these endways.

(b) On the ball or rollers relative to the roller, which again are pinched endways.

(c) By pushing the follower roller into hard contact with the cam on the central position.

It is this last method which The Adamant Company take exception to.

Commander Matravers pointed out that the right way to set up the gear was as follows :-

(Cont'd:-
  
  


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