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).
Inspection notes and recommendations from Mr. Royce on 20 HP chassis components.
| Identifier | ExFiles\Box 49\4\ Scan072 | |
| Date | 18th May 1920 | |
| X.3576 4263 To Hs.{Lord Ernest Hives - Chair} Ds. & By.{R.W. Bailey - Chief Engineer} -6- E1/G18.5.20. Contd. to do the silencer anout job. For press work to be ordered outside Mr. Royce recommeded that we should try Sankeys or Rubery Owen. INSPECTION OF 20 H.P. CHASSIS PARTS. X.3481. A considerable number of the pieces of the 20 H.P. chassis were brought to West WitteringHenry Royce's home town for inspection, some were completed and ready for assembly, while others were in different stages of completion. They are reported on as follows:- Rear Axle Tube. X.3493. This piece Mr. Royce thought was rather heavy. He mentioned that some instructions have been sent to Derby to try as many as possible of the pieces of the 20 H.P. rear axle in two thicknesses, that is to say, in a thickness that we should consider normal, and in another dimension which was 70 or 80% of the normal thickness. By bump testing to destruction two separate axles made up in this way we should obtain valuable information as to the dimensions required. These instructions did not seem to be known. Axle Driving Shaft. X.3539. The drilling of the bore on this piece is rather difficult to carry out, and Mr. Bailey stated that referring to long holes generally they are difficult to do unless bored right through, and the outside of the piece trued up afterwards off the bore. Mr. Royce says, cancel the hole altogether or make it much larger, also bore the hole before the heat treatment of the steel, but after the annealing. Mr. Royce wishes to emphasise that he wants a slow cooling in lime after the normalising of forgings to assist the machining. He has suggested this before, the heat treatment comes later. Mr. Bailey stated that the reason for wanting the normalising and heat treatment carried out together was to avoid cracks. The 20 H.P. axle driving shaft was found to be in chrome vanadium steel and Mr. Royce definitely decided that we could do without the hole altogether through its centre. Main Bearings and crankcase. Mr. Royce remarks that if we go on with the 20 H.P. chassis we shall use main bearing caps on the system decided for the "Buzzard". Front Axle. X.3516. An inspection of the forging of this shewed that it was made as in the sketch, at each end. The "I" section rapidly changed to a flattened section, semi-circular top and bottom. Mr. Royce did not consider this to be satisfactory, and wishes it to be altered so as to be more like the 40/50 H.P. Gear Box. X.3501. The angle on the constant mesh gears was thought by Mr. Royce to be very steep, and in view of the fact that the 40/50 constant mesh gears are quite fine in pitch he wishes a finer pitch chosen for the 20 H.P. with a view to obtaining a small ramble on the teeth. Contd. | ||