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).
Comparing the moment of inertia of a new light type clutch plate unit against a standard one.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan150 | |
| Date | 23th November 1925 | |
| R.R. 493A (50 H) (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF Hs{Lord Ernest Hives - Chair}/ACLL/LG231125 ORIGINAL To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. c. to RG.{Mr Rowledge} CJ. c. to BJ. E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} EY. c. to Wor.{Arthur Wormald - General Works Manager} MOMENT OF INERTIA OF EAC. X8300 CLUTCH PLATE UNIT. We have compared the moments of inertia of the new light type Ferodo clutch plate unit (lec.2102) and the standard by the Bifilar suspension method whereby we determine the radius of gyration from the time of oscillation. The moment of inertia was then obtained by the product of the mass and the square of the radius of gyration. The results show that moment of inertia "I" of the new light type clutch plate unit is 13% less than the standard type. The following results were obtained :- | | Std. EAC. Clutch plate unit. | New light type EAC. clutch plate unit. | | :--- | :--- | :--- | | Weight of complete clutch plate unit. | 16.937 lbs. | 15.687 lbs. | | [Rad. of gyration]² or (K²) | .0557 ft² | .05238 ft² | | Moment of inertia = W/g K² | .0293 units. | .0255 units. | | Decrease in "I" given by new type. | ---- | 12.9% | | Decrease in weight. | ---- | 7.4% | Hs{Lord Ernest Hives - Chair}/A.C.Lovesey. | ||