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).
Use of knurled press fit assemblies for the Phantom III Oil Pump Driving Shaft.
| Identifier | ExFiles\Box 149\2\ scan0128 | |
| Date | 30th September 1936 | |
| 1205 Sft{Mr Swift}/WNW.1/DR.30.9.36. PHANTOM III. Oil Pump Driving Shaft Assembly. In reply to E.1/HP. 23.9.36. regarding the use of knurled press fit assemblies, we are giving our views as requested. Firstly, in connection with the Wraith Shock Damper and Roll Rod shewn on LEC.5133, we were of the opinion that these knurled assemblies offered an economy in manufacture, but at the same time were surprised at their being considered suitable for the assembly of details which resist reversible loads and particularly that well fitting square ended shafts are now used. However, we felt the scheme was cheap to produce and worth trying out and also that its effectiveness or otherwise would be proved on test. Secondly, as regards the Phantom III Oil Pump Drive Shaft Ass. shewn on WKS.00.A. scheme "B" we have the following views:- (a). We do not consider that a press fit serration would entail any greater degree of accuracy than we are now giving to all serrated fits and drives. It appears to us that a suitable allowance only need be made to the dimensions to allow for the press fit. (b). We agree that a broaching operation for serrations is cheaper than when cut on the Fellows and is always preferred by us. In the case in question however, the total time for machining the two pieces is actually 30% greater than for the single piece. (c). The assembly time shewn in the standard figure represented the work involved for pressing together the two details forming the large end, marking off, drilling, reaming, rivetting and filing the pin. As this work does not appear on the "B" scheme it was not included. The time for pressing of the End Pieces to the tube will be very small and will be absorbed in the main assembly of the Oil Pump and Drive. Sft.{Mr Swift} | ||