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).
Potential solutions for issues with the Phantom Gearbox's second speed synchro-mesh.
| Identifier | ExFiles\Box 179b\1\ img218 | |
| Date | 1st December 1932 | |
| RS.{Sir Henry Royce's Secretary} FROM HDY.{William Hardy} HDY{William Hardy}1/wS.12.32. PHANTOM GEARBOX - SYNCHRO MESH 2nd. SPEED. X7310 We shall no doubt have instructions from R.{Sir Henry Royce} before long on this question, but in the meantime we see several possibilities about which we should like to have your views. We are assuming that the cones will be placed on the 3rd. motion shaft in order to get the lower speed of the gears in top gear. The drawbacks to this arrangement are of course increased torque required from synchro mesh cones in 2nd., and also in top and 3rd., and increased idling noise. With regard to the increased torque: (1) Is there anything to be gained by further reduction of oil level to the extent of no immersion of gears but lubrication by oil jets and pump? (2) By means of a cam we can for example double the leverage during the synchronisation period - i.e. the first .200" travel of the sleeve on the 3rd. motion shaft, at the expense of the latter part of the travel where the leverage would become one half what it is now. This would only be satisfactory if the engagement and disengagement of the teeth never requires much effort under present conditions. Would you kindly say whether this is so. (3) Our impression is that an increase in the movement of the change gear lever is not possible, and in any case is undesirable. We shall of course be making the travel in 2nd. speed the same as in top and 3rd. With regard to the increased idling noise it occurs to us that something may be learned from the car with silent 2nd. by idling with 2nd. [REDACTED] engaged, and the axle jacked up. [Signature] HDY.{William Hardy} | ||