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 gearbox speed wheels to overcome cone drag and baulking.
Identifier | ExFiles\Box 136\2\ scan0343 | |
Date | 23th January 1942 | |
-cont'd- -3- EV{Ivan Evernden - coachwork}/Tin.1/KO.23.1.42. The proper cure is to produce new 1st speed wheels correct to drawing; but it is possible to alter the existing parts to make them usable. By cutting one pair of cam faces .06" deeper on the 1st speed wheel we should over-come cone drag, and by modifying the cone so as to allow it more rotational freedom we should achieve the baulking which is now absent. This mocking up of the 2nd speed has disadvantages, but not serious ones. The tongue on the cone will be slightly weakened and will be soft; one pair of cam faces will be soft and the increased freedom of the cone will give the driver a slightly better chance of "beating the baulk". If new 1st speed wheels are made, we should like to do something about the strength of the 2nd speed dogs. Strengthened dogs have been designed, but were not included in the instructions for these gearboxes because new cutters would have been necessary. However, using existing cutters and without affecting the mating piece, slightly stronger dogs can be produced by lengthening the teeth and reducing the backing-off. If a new piece is decided upon, we would like these features incorporating. The original is attached to Rm{William Robotham - Chief Engineer}/HH's copy for issue and correction of detail drawing. Ev{Ivan Evernden - coachwork}/Tln. Prints to: Ev{Ivan Evernden - coachwork}, Rm{William Robotham - Chief Engineer}/IG, Rm{William Robotham - Chief Engineer}/FJH{Fred J. Hardy - Chief Dev. Engineer}, Rm{William Robotham - Chief Engineer}/Wym{G. Harold Whyman - Experimental Manager}, & Ashby. | ||