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).
Supercharger impeller blade fracture during testing, noting clearances and material hardness figures.
| Identifier | ExFiles\Box 42\3\ Scan015 | |
| Date | 21th December 1934 | |
| contd :- -2- 0.200" and the clearance between the impeller blade tips and the diffuser vane tips is 0.240", instead of 0.200". Fracture of impeller blade. After 3 hrs. running, one of the impeller blades broke off while running at 18,000 r.p.m. The supercharger had previously been run 1 1/2 hrs. at 12,000 r.p.m. and one hour at 20,000 r.p.m. Fracture took place at the root of the blade, where the latter joins on to the radius. The brinell figure for the blade was 269, and for the impeller shaft 277. The brinell called for on the drawing is 286 - 311 respectively. Hs{Lord Ernest Hives - Chair}/A.{Mr Adams} A.{Mr Adams} Rubbra. Complete set of prints sent to R.E.RG.{Mr Rowledge}BY. | ||