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).
Tests of a P.V. 40/50 Tank Engine starter motor's operation when inclined at an angle.
| Identifier | ExFiles\Box 62\1\ scan0251 | |
| Date | 9th May 1934 | |
| E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. c. to By.{R.W. Bailey - Chief Engineer} c. to Mx.{John H Maddocks - Chief Proving Officer} c. to Wor.{Arthur Wormald - General Works Manager} P.V. 40/50 TANK ENGINE STARTER MOTOR. We have been carrying out tests to discover whether the starter motor will operate satisfactorily on the Phantom II engine when it is inclined at an angle of 45° either fore or aft. It was found that the motor pinion would slide into gear when the engine was inclined with the timing gear end uppermost and with the engine inclined with the flywheel end uppermost, the teazer pull was insufficient to draw the teeth into engagement. A stronger armature return spring was then fitted to the motor of sufficient strength to prevent the armature slipping into gear and also to return it every time to the out of gear position. It was found with this arrangement sufficient teazer current could be supplied by suitably altering the winding to cause the pinion to engage, although the engagement would necessarily be violent under normal conditions, i.e. horizontally. There is however a more serious fundamental difficulty in the operation of the motor at this inclined angle. This is due to the fact that the main current, which is governed by the turning torque of the engine, gear ratio etc., and electrical starting characteristics of the motor, is insufficient to hold the motor into engagement with the strong spring even in the horizontal position therefore at an angle of 45° it would be impossible to work the motor in mesh with the engine on the main circuit. This fundamental objection, we consider, rather rules out the use of a sequence type of starter for the conditions laid down. | ||