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).
Review and commentary on articles from the S.I.A. journal regarding electrically operated gearboxes.
| Identifier | ExFiles\Box 136\2\ scan0263 | |
| Date | 3rd May 1940 | |
| 1153 To Rm.{William Robotham - Chief Engineer} (Strikethrough) c. to Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} Ev.{Ivan Evernden - coachwork}16/JH.3.5.40. re Electrically Operated Gearboxes. JH (handwritten initials) In the Jan/Feb. 1940 Journal of the S.I.A. there are three articles on gearboxes as follows :- (1) Page 21. Electro Magnetic Speed Change. by von Soden-Fraunhofen. (2) Page 27. Cotal Electro Magnetic boxes. by M.Jean Cotal. (3) Page 32. Developments on the Cotal box by M.Jacques Elwell With respect to the Soden-Fraunhofen.box, Mr. Tarlton quite rightly points out that this in many respects, appears the same as the Rover electrical synchromesh of which you have already given us particulars. Nothing is said concerning the design of the magnets. With respect of the paper by M.{Mr Moon / Mr Moore} Cotal. This is interesting although not very constructive. Here again nothing is said about magnets. He claims that the torque capacity of the box can be increased by increasing the number of pinions and suitably increasing the magnet flux. We can see that this can be true and that at the same time either boxes will not be badly disproportioned with respect to stresses and weight. According to the inventor we could make a 3 litre box for our 5 litre engine. Have we heard anything from Sr. on this subject? if not we could write to M.{Mr Moon / Mr Moore} Cotal. Following up this line or argument, however, the area of the pole pieces and the amount of iron in the magnet cannot be right for both boxes. | ||