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).
Specifications for a universal gearbox for Bentley III, Phantom, and Wraith models.
| Identifier | ExFiles\Box 136\4\ scan0168 | |
| Date | 16th July 1937 | |
| PY: c.c. Mr. Ds. Rm.{William Robotham - Chief Engineer} HPS.{Horace Percy Smith - Experimental Factory Mgr} GRL 1153 E/HDY.{William Hardy}1/HP.16.7.37. Bentley III, Phantom and Wraith. Universal Gearbox. We send herewith N.Sch.5193, 5199, 5200, and 5201, showing the above. N.Sch.5193 shows the gears, shafts and bearings. The gears shown give over-drive ratios as requested by the Experimental Department for the Bentley and Phantom, but standard ratios can be provided if required. The first motion shaft as shown is correct for the Phantom but must be reduced at the front end to suit the smaller splines used on the 10" Borg and Beck clutch for the Bentley. We cannot give particulars of the interference required between the cones and the gears for the hydraulic press fit until we know the results of experiments which are being made to determine this point. The remarks given in E/HDY.{William Hardy}3/M.21.5.37 and E/HDY.{William Hardy}1/M.29.5.37 in connection with N.Sch's 5146 and 5151 showing temporary applications of the Buick synchromesh should be referred to. The gears and shafts are of S/ZNX. The former are not hardened on the splines. The latter are hardened on the splines and bearing journal surfaces. The helical angles of the gears on the reverse shaft must be calculated to give a balanced thrust on the reverse shaft and the lead of the splines for the 1st speed driven gear should be the same as the lead of the gear teeth. The 1st speed splines should be of our standard six spline type with the gear bearing on the base diameter of the spline. The synchromesh springs are almost identical with the Buick springs but we think that a lower rating will be | ||