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).
Issues and potential improvements for a gearbox with an epicyclic 3rd speed and Maybach clutch.
Identifier | ExFiles\Box 6\2\ 02-page169 | |
Date | 17th April 1931 | |
To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to SE. Cor. c. to E.{Mr Elliott - Chief Engineer} Dn. c. to Ey. Hs.{Lord Ernest Hives - Chair}2/MJ.17.4.31. YJ-200 GEARBOX WITH EPICYCLIC 3RD. SPEED. We have had this box running again having altered the angle of the jaws on the Maybach dogs from 0° to 4°. We tried this whilst waiting for the two and three jaw type with the 2° angle. Reducing the angle of the jaws has reduced the distressing noise when changing but as the jaws have been damaged by the previous treatment it is not a very conclusive test. One trouble we are investigating is that if you do not use the clutch the Vacuum operated toggle does not work quickly enough to change the gear before the drive is taken on the opposite side of the teeth which then holds it from changing over. It means then that you either have to give an extra flick of the accelerator or release the clutch. We think it should be possible to overcome this trouble. We have now had a fair amount of experience with the Maybach clutches on 14-EX. and on 27-EX. and our impression is, although we admit this may be premature, that although the change is simple and silent on a comparatively open road it needs more intelligence than the straight forward lever when you come to operate it under congested traffic conditions. In traffic conditions the load may or may not be on the jaws when you change. You have to think whether it is a question of having to speed the engine up or to slow it down, according to which way you are changing. We may alter our view, but I always find myself using the side lever in a traffic jam. We have been one of the advocates of the Maybach clutch but we are altering our views with experience. We are still pushing ahead to get this box perfect because we can quite believe that when we have got rid of the obvious faults, it may become a very different proposition. Hs.{Lord Ernest Hives - Chair} | ||