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).
Three proposed schemes for the Phantom III back axle hub driving dog.
| Identifier | ExFiles\Box 92\5\ scan0121 | |
| Date | 4th May 1937 | |
| 302. BY: c.c. E.{Mr Elliott - Chief Engineer} R.{Sir Henry Royce} Rm.{William Robotham - Chief Engineer} HPS.{Horace Percy Smith - Experimental Factory Mgr} E/HDY.{William Hardy}1/HP.4.5.37. Phantom III Back Axle. We send herewith N.Sch.5139 showing a hub driving dog with reduced length and increased depth of teeth, on the lines of the alteration now on test for the Bentley. We show three schemes as follows:- (1) The best that can be done with an existing machined hub. The hub teeth are deepened. A new oil tight cover is required as the chamfer on the present piece causes too much loss of tooth depth. There are no other new parts than the driving dog and cover. The effective length of the teeth is reduced from .500 to .440, but the area is increased 32%.compared with the standard teeth. (2) Increased area is obtained compared with (1) where it is possible to have a new hub. To obtain sufficient clearance when a standard stud is used for the axle tube nut locking plate and a thickened driving piece is used, we have lengthened the axle shaft .050. We do not regard new shafts as essential but the increased clearance given is desirable. The increase of area compared with the standard teeth is 71%. (3) This scheme gives no increase of area over (2) but the teeth are more robust and should, therefore, distort less in the hardening than with (2). A new axle tube is required as well as a new hub. The outer hub bearing is moved towards the inner bearing giving more space for the driving piece and enabling the trepanning operation to be avoided. In all cases the driving pieces are of S/ZN case hardened on the external teeth. We prefer scheme (3). E/HDY{William Hardy}, | ||