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).
Experiments to fix motor engagement issues by testing additional torque, current, and different spring arrangements.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan135 | |
| Date | 15th February 1929 guessed | |
| -2- Contd. to determine whether it was a question of additional armature torque we made the experiment of feeding in additional current at the main motor terminal at times when corner jams occurred, but we found that, provided the crankshaft was not allowed to turn (i.e. as under teazer action only) it required an unreas-onable amount of additional armature current and torque to make anything further happen. Next, the main spring was again changed to another arrangement of rather lower rate spring and bigger packing which we had found equally suitable with the arrangement mostly used, but giving a rather greater set up load in the position of pinion just engaging. We now experienced a considerably reduced frequency of jam and could in one instance get 100 consecutive engagements on normal voltage without failure. It might then be said that the first weakness of the system as the voltage was reduced was failure to fully engage and make the motor contact. (N.B. as originally arranged, the timing of the make of this contact has mainly been too late and it has been necessary to ask for an altera-tion to make this contact somewhat earlier. We are not here speaking of the much earlier contact which had been tried as a separate experiment and found to give no unsatisfactory result, but of the fact that the contact sometimes has not been early enough to prevent in some cases the motor breaking the contact and coming out of gear of itself, i.e. without the engine starting). Contd. | ||