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).
Testing and modifications to a Bentley III propeller shaft to eliminate juddering.
| Identifier | ExFiles\Box 97\4\ scan0101 | |
| Date | 31th October 1938 | |
| 4006 To. Rm.{William Robotham - Chief Engineer} [struck through] CHATEAUROUX. 1/.31.10.38. 8.B.V.- BENTLEY III. Propellor Shaft We have received the new propellor shaft and fitted the sliding joint and rear universal joint to the existing shaft. We noted that holes have been machined in the end flange for the purpose of giving increased angularity. We tested the car with this new rear joint fitted, loaded to capacity, at maximum torque in bottom gear, and found that the propellor shaft judders occurred as before. Examination showed that the joint was fouling in the fork on the sliding piece, (as shown in sketch) and also on the 3/8" castellated nuts. These fouls were found to occur at 21° angularity. [Drawing of a universal joint yoke] [Annotation on drawing]: FOULS HERE [Annotation on drawing]: HOLES FOR EXTRA CLEARANCE [Handwritten initials]: FJH{Fred J. Hardy - Chief Dev. Engineer} We then measured the angularity permitted by the holes if no nuts were there to restrict the movement. This was found to be 26°. The jaw was then filed away where the foul shown in the sketch occurred to give 26° in this direction as well. The four 3/8" bolts were reversed so that the nuts are now towards the axle. This has necessitated dispensing with split pins and using three quarter thickness nuts and spring washers. The car was again tested and with four people and 280 lbs in the luggage boot, and it was then found that no prop. shaft judders occurred with steady maximum acceleration in bottom gear, but that they could be produced by manipulating the clutch in a brutal manner. ------ Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} | ||