Modifications to the Wraith III Gearbox to make gear wheel bosses flush with the rims.
| Identifier | ExFiles\Box 8\11\ 11-page079 | |
| Date | 24th April 1937 | |
| SECRET. c.c. Bx. BA. RHC. {R. H. Coverley - Production Engineer} Rm. {William Robotham - Chief Engineer} HPS. {Horace Percy Smith - Experimental Factory Mgr} 628 Wraith III Gearbox. FLUSH. We have been requested by RHC {R. H. Coverley - Production Engineer} to make gear wheel bosses with the rims where it is possible to do so, in order to improve the location of the gears when being broached. This applies only to gears with unhardened splines where the broaching is necessarily performed after the teeth are cut and carbonised. To carry this out on the Wraith the following modifications must be made:- Constant Mesh Wheel. The front end of the boss should be made flush with the rim and the washer between the gear and the roller bearing should be thickened by the amount taken from the boss. Third Speed Driving Gear. The rear end of the boss is made flush. The ball bearing moves forward the amount taken from the boss and the distance piece GW.872 is lengthened correspondingly. There will still be sufficient clearance between the outer race of the bearing and the gear rim. First Speed Driven Gear. The front face of the gear is made flush. According to GL. {G. Linnett} 835 there will still be sufficient clearance between the gear and the diaphragm when the gear is forward against the ball bearing. Second Speed Driven Gear. This gear appears to be flush already at the rear end. If not it should be made flush and the washer altered accordingly. | ||
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).