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).
Technical memorandum discussing future possibilities for a silent, easy-change gearbox.
| Identifier | ExFiles\Box 15\5\ Scan249 | |
| Date | 3rd March 1932 | |
| E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} c.c. to Da.{Bernard Day - Chassis Design} c.c. to By.{R.W. Bailey - Chief Engineer} X7310. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}/1/MA. 3. 3. 32. X5310. GEAR BOXES. Hs.{Lord Ernest Hives - Chair} has suggested the future possibility of a silent easy change 2nd gear. In connection with this there are various points worth considering. At least 3 sets of helical continuous gears are required. By using all the combinations of these, 4 silent gears of suitable ratios can be obtained. A further 4 spur pinions are then required in order to provide a reverse gear. This system shown in Fig 1 allows of the normal type of gear gate and synchromesh operation. With the engine idling all 3 sets of continuous gears are turning. A better scheme employed by certain manufacturers is to have the constant mesh gears at the back of the box. Then with the engine idling none of the continuous gears are turning and there would be no side shaft noise. Fig.II shows an adaptation of this to 3 silent gears with a spur 1st and reverse gear. A further advantage is that smaller synchromesh cores could be employed as the torque required from them is less than inour present system. The sliding 1st pinion is only under engine torque and would not probably work out of mesh under load. The disadvantage of this scheme is that with the ordinary selector mechanism one would push and not pull the gear lever into top gear. It would seem worth while to have a more complicated mechanism to overcome this in order not to have to worry about side shaft noise. The reason we think why this method has not often been used is that on an ordinary gear-box the linear speeds of the engaging teeth is increased with a consequent increased difficulty in gear changing. This does not arise with a synchromesh change. Hs{Lord Ernest Hives - Chair}/H.{Arthur M. Hanbury - Head Complaints} Grylls. Att: Hs.{Lord Ernest Hives - Chair}553 | ||