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 operation of Bendix and Bijur starter drive mechanisms.
| Identifier | ExFiles\Box 40\5\ Scan061 | |
| Date | 16th December 1921 guessed | |
| - 4 - the offending flywheel tooth while being rotated by the barrel with the starter shaft. This is further helped by the slanting end of the pinion teeth as shown in the sketch. As soon as the teeth are uncovered, the compressed spring snaps the pinion into mesh and normal cranking takes place. In this manner, it is impossible to "jam" the pinion teeth against the flywheel teeth, and positive and complete meshing of the starter and engine is obtained every time the starting switch is closed. It is not necessary to try more than once in order to obtain meshing. In your letter, you make reference to the Bendix drive, with which you intend to compare the Bijur form of drive. I may therefore point out to you a difference of operation under certain conditions. Thus, while the Bendix drive is manufactured under license from our Company, it differs among other features in that the pinion forms also the nut, since the thread is cut right into the pinion, which rides directly on the threaded sleeve. The result of this construction is that in case a pinion tooth butts against a flywheel tooth, the pinion is screwed against the flywheel like an ordinary nut, and very energetically since this is done by the electric starter. There is therefore the possibility of jamming solidly the starter and engine, which prevents the rotation of either. Or else, the teeth of either flywheel or pinion may be broken or sheared away. This danger, although not completely avoided, is minimized in some degree in the Bendix drive by giving a rather considerable radial play between the pinion and the threaded sleeve. This permits frequently to the pinion to enter into mesh despite butting, in that the pinion jumps into place thanks to this radial play. The disadvantage of this construction however is that when cranking, the pinion "floats" radially, and the cranking is noisy. With the Bijur drive, jamming and butting are avoided in a different manner, as explained above. It is not necessary to have radial play on the pinion, which, in fact, is mounted on the shaft as close fitting as possible, leaving just enough clearance to permit an easy sliding motion of the pinion along the starter shaft. It is then possible to mount the starter on an | ||