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).
Modifications to a gearbox to address issues with torque bind and gear selection.
| Identifier | ExFiles\Box 6\4\ 04-page062 | |
| Date | 17th March 1925 guessed | |
| -2- Keys narrowed so that torque bind must be only under gear which is driving. SEE ORIGINAL FOR SKETCH. If this does not cure second speed(using a fork which is free and amply slack cut away clearance) then we should compare with 1st. speed of 40/50 box. Regarding the 1st. speed this is not surprising up to what has been done because of the small dia. and 20º giving great disturbing effect compared with binding effect on the keys. If the narrow keys (so that keys only drive under small pinion when this is in gear) are not a cure, (and 40/50 is O.K. and dis-similar proportion of dia. of shaft and gear) then we must do as I suggested at first i.e. increase the dia. of the pinions (higher 1st. speed) which is no loss. Use 14½º teeth as on 40/50 and thirdly perhaps make the keys to help keep the gears still, thus :- SEE ORIGINAL FOR SKETCH. In conclusion you will see that my impression (I hope wrong) is that you have done nothing logical to effect a cure, (and xxx ought not to expect one), and you seem to have steadily ignored my suggestions, either because you do not see the reasons for them or think they are worthless. Naturally I am anxious to get this work right quickly. No-one has said a word about comparison with other similar boxes, and our own 40/50. I am inclined to say wake up Derby and WW. R.{Sir Henry Royce} | ||