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).
Preliminary report on the design, testing, and issues found with a new semi-floating axle.
| Identifier | ExFiles\Box 114\1\ scan0146 | |
| Date | 19th August 1938 | |
| 1015. also. 402. By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} c. Hs.{Lord Ernest Hives - Chair} c. Da.{Bernard Day - Chassis Design} c. Hy{Tom Haldenby - Plant Engineer}/Hdy.{William Hardy} c. HPS.{Horace Percy Smith - Experimental Factory Mgr} Rm{William Robotham - Chief Engineer}/GryS/R.19.8.38. Semi-floating Axle. The following is a preliminary report on the new axle. Even allowing for the fact that because of a semi-floating rear axle we can use lighter front hubs, the new axle to the original P.D's adds 24 lbs to the 'M' Series Bentley. Da.{Bernard Day - Chassis Design} is, therefore, preparing designs to save weight incorporating :- (1) Lighter axle tubes having a parallel portion in the middle and reduced in diameter at the large end. (2) Spring seat separate from the wheel bearing flange, the latter becoming part of the axle tube. (3) Half shaft 40 mm under the wheel bearing. As regards the mechanical side, the shrunk on wheel bearing retaining collars move back about 1 1/2 thousandths on cooling and after the dynamometer run even the bearing had .003 end play. We recommend, therefore, the Vauxhall arrangement of Belleville washer to take up slack. So far no car has done any road running on this axle, but a dynamometer run has been done as follows:- 30 hours on the normal Bentley 3rd gear 2000 rpm. 70 " " top gear " " After the first 30 hours the pinion was looked at and found to be slightly picked up. After the complete run the axle was stripped and the following points noted:- (1) The wheel bearings had .003 end play on the shafts. | ||