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).
Proposal for a new starter motor system using a double reduction gear mechanism.
| Identifier | WestWitteringFiles\T\January1929-February1929\ Scan171 | |
| Date | 21th January 1929 | |
| B. RFC.) FROM R.{Sir Henry Royce} BY.{R.W. Bailey - Chief Engineer} HS.{Lord Ernest Hives - Chair} ) (At Le CanadelHenry Royce's French residence.) ORIGINAL R1/M21.1.29. REC'D AT WW. 26.1.29. C - to BJ. WGR. SG.{Arthur F. Sidgreaves - MD} Mr CLAREMONT. STARTER MOTOR SYSTEM. x7655 Here is a new modification which may be thought worth a British provisional. In starting a large engine we would like to use a small motor running at high speed to get good efficiency and high stalling torque. This suggests double reduction gear of either epicyclic or spur gear 1st. motion, and the usual 2nd. motion. The idea is that the 1st. motion could be spiral, the motor armature not moving endwise, but by the action of the spiral gear on rapid acceleration it pushes the second motion gear and pinion along its bearings and causes the 2nd. pinion to engage with the flywheel. Flywheel gear. End shock damped as suggested for sequence. See other sketch. Fitted with friction drive limiting torque. Jump back pinion. This would be used with foot or magnetic main switch to bang right on (no teazer). ADVANTAGES: Larger second pinion, motor speed doubled compared with engine - i.e. about 25 to 1 ratio, therefore power and efficiency of motor much greater, less costly than our sequence, quiet gearing. It can be made with epicyclic gears for 1st. motion. The parts moving endways are light compared with moving the armature. The spiral angle can be varied to give suitable proportion between end pressure and torque. The inertia of the whole of the second motion parts is available for obtaining end motion, and the inertia of the armature is available for throwing out the pinion. See further sketch on sheet (2). (1) R.{Sir Henry Royce} | ||