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).
Design of change gears, specifically the issues with Maybach jaws and comparing them to alternative schemes.
| Identifier | ExFiles\Box 6\2\ 02-page146 | |
| Date | 2nd March 1931 | |
| HS.{Lord Ernest Hives - Chair} DA{Bernard Day - Chassis Design}/HDY.{William Hardy} R.{Sir Henry Royce} FROM R.{Sir Henry Royce} (At Le CanadelHenry Royce's French residence.) X653 F1/M2.3.31. c. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} CHANGE GEAR. MAYBACH JAWS ETC. X.2200. X.525. X.4510. (1) It does not seem that these will work when we try to change from top to 3rd., and also from 2nd. to 3rd., because the jaws would need to be a different way round in each case, which is of course impossible. (2) It occurred to me that to avoid a crash in the grabbing direction we might try one of Salerni's baulk rings so that we had Salerni protection one way and Maybach the other, so that it would not crash either if the driver were too fast or too slow. (3) You will remember that I have never recommended grabbing jaws or backed off teeth, but always rounded ones that would not go in until synchronised, and it seems that there are great difficulties to get away from this. (4) I understand that the Chrysler car had Maybach jaws but I may be under some wrong impression. I thought Mr. Hardy mentioned it in a recent memo. (5) I think - with HS.{Lord Ernest Hives - Chair} - that they are only suitable as used on the Maybach car - i.e. always under the same conditions and without hesitation. We can make a useful experiment under these conditions. (6) If my para. (2) is no good then I fear the job is wrong as we are trying it, but it is quite easy to have Japan made with ordinary jaws. Our scheme of double top is like, or nearly like, Maybach, and can be made satisfactory as far as I can see. We have also another scheme which ought to be good. It is the complete (accelerated) train of epicyclics with synchronous mesh scheme, by bringing each annulus to rest - i.e. simply handle deliberately - some slight knowledge to go slowly enough, but no ill needed. This and our double top are two good schemes for easy change. Silent gears should present no difficulties: all our schemes provide these. We may have to cancel the Maybach's on the 3 speed box for the double top. R.{Sir Henry Royce} | ||