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).
The cost and performance testing of an aluminium servo worm wheel for a Bentley III servo drive.
| Identifier | ExFiles\Box 152\2\ scan0232 | |
| Date | 14th October 1938 | |
| COPY FOR FILES. 81294 also 441 TYPED 14.10.38. BENTLEY III Servo Drive. The material cost of a bronze servo worm wheel is 3/4 We can save 2/- in material cost if we use an aluminium wheel. There is also a saving in machining cost. We have run an aluminium B.II servo worm wheel in a standard B.II. gearbox for 100 hours on the dynamometer chassis. A load equivalent to 100 lbs. on the pedal was applied for 2 seconds every minute, i.e. 6,000 applications. In addition we applied a load of 200-250 lbs. on the pedal for 4 - 5 seconds duration twenty times, to see if we could break the teeth. The wheel has pitted slightly at one side of each tooth, this was not observed until after the overload test. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} | ||