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).
Motor and gear performance, detailing issues with engagement, disengagement, noise, and clearances on various systems.
| Identifier | WestWitteringFiles\T\November1928\ Scan081 | |
| Date | 12th December 1928 guessed | |
| -3- Contd. would not recede but appeared to require nothing more than a tap of the wooden handle of the screwdriver on the carcase to enable it to do so, showing that this fault is merely a question of proper bearing clearances. The power of the motor is very much better and turns the engine a good deal faster (speed not actually measured). The gear noise when rolling the engine does not appear to be as satisfactory as we could hope for. The armature recedes from engagement when the engine starts more promptly than one would have expected in the circumstances, but continues to rotate for, we think, about 8 seconds after complete disengagement. There does not appear to be so much of a gear scream on disengagement as in the case of the 5º spiral teeth on the 9-EX system. There is a slight knock on engagement independently of the actual main current for which the contact is timed to make about .075" before full engagement. The knock when the armature comes out of gear is perhaps the most serious fault. As stated, this has been greatly minimised experimentally on the 9-EX system by a <crossed_out>liquid</crossed_out> <handwritten>fluid</handwritten> (air) friction damper. As stated, this longer motor seems to come out of gear more quickly than anticipated and more quickly than the shorter armature motor which you saw on chassis 18-EX. <handwritten>(Straight teeth)</handwritten> In this case (18-EX) there appeared to be some gear scream on disengagement as if the motor took longer to come out, and the motor could be heard to be spinning fast after disengagement. At the same time the outward thump was perhaps not so bad as | ||