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).
Proposed modifications to the P.2. Gearbox, including the R.H. and Central Change Gear.
| Identifier | ExFiles\Box 123\3\ scan0122 | |
| Date | 3rd February 1934 | |
| To EY. from HDY.{William Hardy} c. Sg.{Arthur F. Sidgreaves - MD} Hcr. E.{Mr Elliott - Chief Engineer} Hs.{Lord Ernest Hives - Chair} Da.{Bernard Day - Chassis Design} RMC. EV.{Ivan Evernden - coachwork} P.2. Gearbox with B.M. 2nd. R.H.and Central Change Gear We send herewith N. Sch's 3964/5 which shew the gears and actuating mechanism for the rear half of the above gearbox. The front half of the box is shown by N. Sch.3968 which will follow on Monday next. Unit construction is retained and the box suits the present clutch casing without alteration to the latter. The servo is on the same side as now and is the same distance from the centre line of the car, so there should be no alteration to the brake gear as far as the gearbox is concerned except to move the rear countershafts bodily backwards an amount equal to the increased length of the box which is 2.3". The change lever shaft is 5" further forward than it is now in order to enable a central change lever to be used with a gate which will be reasonably clear of the seats. We propose to lengthen the change lever by 2" giving an 18" lever but the leverage of actuation will be such that the travel at the end of the lever is the same as it is now. The gearbox shaft centres, shaft diameters and gear teeth particulars are unaltered excepting for 1st and reverse gears. 1st is raised from .28 to .31 and reverse is .3. These alterations are made to suit the 2nd speed S.M.sleeve. The 1st speed pinion is the same width as now but the bearing surface width is reduced from .675 to .600 owing to the rounding of the wheel teeth at both ends. The diameter of the 2nd speed synchromesh clutch is 97% of that of the present 3rd speed clutch and is the largest clutch that will clear the 3rd motion shaft. | ||