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).
Trial of a Spectre gearbox using coarse pitch gears with a 45-degree helix.
| Identifier | ExFiles\Box 94\1\ scan0108 | |
| Date | 28th March 1935 | |
| 7328 Hardy Rm{William Robotham - Chief Engineer} To EY. Copy to Nor. HS.{Lord Ernest Hives - Chair} RMO. ---------- HDY{William Hardy}/1/MN.28.3.35. SPECTRECodename for Phantom III GEARBOX. Coarse Pitch Gears with 45° Helix as on the Cadillac C/M 3rd.& 2nd. N.Sch.4434 herewith shows the above for trial to determine, if possible, whether they have any advantages over what we are now using for silence and strength with less length. We have incorporated the ball bearings as shown by N.Sch.4405. No alterations are required to the casing or shafts at this stage but we think that some of the bearings we are now using will be inadequate for permanent use to take the end thrust with a 45° angle. It will be seen that the constant mesh and 2nd.speed gears have the same particulars and there is therefore a saving in the amount of grinding tackle required for this experiment. The Cadillac correction as shown on N.Sch.4414 should be given. 1st. speed and R gears are unaltered except for the chamfer on the reverse pinion and the washer to limit the movement of the R shaft. We show the gears without any lightening in order not to depart from Cadillac practice. HDY.{William Hardy} Att: N.Sch.4434. | ||