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 design and testing of gear teeth for a starting apparatus, focusing on noise reduction and engagement.
| Identifier | ExFiles\Box 64\4\ scan0024 | |
| Date | 26th November 1927 guessed | |
| -2- scheme, we are of the opinion that in this No.2A (and No.2B) case also the entering corners of the teeth should be as sharp as is reasonably possible with the material used in order to reduce or practically eliminate the frequency with which the apparatus does not function upon the first press of the button. Apart from that phenomenon and the objectionable noisiness of the gear teeth when rolling the engine, this No.2A apparatus,has, as stated, operated very satisfactorily on chassis 14-EX, and this with a spiral angle of 5º. As to whether parallel teeth which apparently have some chance of being cut for reduced noisiness would give such a satisfactorye operation, it appears to us that such would not be the case. It will be remembered that to get a satisfactory relation of the nett longitudinal force to move the armature into engagement as compared with the turning torque of the motor on the teazer current, we have had to use a comparatively light spring. Even if the initial engagement, etc. functioned satisfactorily up to the point of the engine being fired, would it not be the case with parallel teeth that the motor would be violently accelerated by the engine before the armature spring had a reasonable chance of dis- engaging the armature pinion ? We are producing two sets of pinion and wheel teeth to be cut as accurately as possible; one set to be parallel (and therefore presumably noiseless) as an experiment on the Contd. | ||