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).
Typed report discussing clutch roller compression and the loss of energy during clutching.
| Identifier | WestWitteringFiles\R\2October1927-November-1927\ 96 | |
| Date | 1st May 1927 guessed | |
| -6- Thus the bulk of the compression in the roller, which is really effective in producing the jam, will occur at the outer extremity. In order to avoid this it is suggested that the surfaces should be progressively filed away so that the rollers should, while tight at the cross-section AB (fig. 1) be looser and looser (in the initial positions) as one moves from AB outwards. The exact figuring of the surfaces to meet all these conditions would probably add very largely to the expense of making the clutch. It is suggested, however, that the same result could probably be reached by making the inner and outer surfaces hyperboloids of the same type as the locus (I), but with different values of α , a value α₁ < α being chosen for the inner surface and a value of α₂ > α for the outer surface. These values will probably have to be found first of all by trial and error, but once found they can be standardized and the surfaces can then be cut by means of a suitably inclined tool, as previously suggested (the suggestion is due to Mr. Humfrey himself) in para. 4. If this were done it should be possible to obtain a much more uniform distribution of pressure on the rollers. This is of great importance in view of the considerations set forth in the next paragraph. 6. LOSS OF ENERGY IN CLUTCHING. I understand that one of the uses to which it is intended to put this clutch is intermittent action of comparatively high frequency. Under these conditions the question of loss of energy in clutching (followed almost immediately by unclutching) becomes important, as it may then involve a serious loss of power, as well as an awkward evolution of heat. | ||