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).
Rapid disengagement of starter motors, specifically relating to the helix angle of the flywheel gear.
| Identifier | ExFiles\Box 62\1\ scan0255 | |
| Date | 19th June 1933 | |
| E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. Hs{Lord Ernest Hives - Chair}/Wst.4/MA.19.6.33. RAPID DISENGAGEMENT OF SEQUENCE STARTER MOTORS. We have referred to our records and find that the helix angle on the flywheel gear ring which was fitted experimentally some time ago to 14-EX., was 5°. We remember that with a larger helic angle there was a tendency for the motor to oscillate endways as the engine bounced over successive compressions. With the air damper this effect would not be noticed but on the old motor it caused a knock. With a helical gear we could have a much less powerful armature return spring as the gear teeth friction on engagement would be less and the disengagement would be more positive. This would allow us to have a finer gauge teazer winding giving a reduced armature current and torque. Hs{Lord Ernest Hives - Chair}/Wst. | ||