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).
Investigation into cone drag and baulking issues for the 3rd, 4th, and 2nd speed senior gearbox.
Identifier | ExFiles\Box 136\2\ scan0342 | |
Date | 23th January 1942 | |
Chassis File To Rm.{William Robotham - Chief Engineer} c. to EV.{Ivan Evernden - coachwork} c. to Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} c. to EV{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} c. to Rm{William Robotham - Chief Engineer}/HH. 1153 EV{Ivan Evernden - coachwork}/Tln.1/RG.{Mr Rowledge}23.1.42. FL.1181 - Investigation of Cone Drag, etc. 3rd & 4th Speed - Senior Gearbox. The first two gearboxes of the six instructed some months ago have been assembled and are found to suffer from cone drag on all cones and also from lack of baulking in one direction on second speed only. The pieces and details have been examined in the design office, and the above scheme has been produced to show :- 1. The conditions existing in the actual gearbox. 2. The conditions which should exist according to details. 3. Modifications which might be made to the parts already produced in order to make the gearboxes usable. 3rd & 4th Cones. The trouble here is that the cam faces on the cones and/or sliding piece are not cut deep enough, and the details appear to be at fault. The error originated in the details instructed for the 13th and subsequent B.V. production boxes, and was not discovered because no such boxes were made. The cure is to cut the cam faces deeper, and this is more easily done on the sliding piece than on the cones. About .040" must be removed from each cam face, and this should be a fairly easy grinding operation. The result will be to expose fairly soft metal on the cam faces, but this is acceptable. We recommend that all the sliding pieces for the 6 Senior gearboxes be altered to the dimensions given on the scheme, and the detail drawings be corrected. 2nd Speed Cone. The details have been drawn out and are satisfactory. The trouble appears to be due to incorrect broaching of the 1st speed wheel (which embodies the cams and dogs of the 2nd speed synchromesh); the internal splines not having the correct angular relation to the cam faces. - continued - | ||