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).
Comparing the efficiency of a type 410 Marles steering gear from Adamant Engineering Co. against the model currently in use.
| Identifier | ExFiles\Box 153\1\ scan0146 | |
| Date | 25th May 1938 | |
| 1300 To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}4/MH.{M. Huckerby}25.5.38. MARLES STEERING GEAR. We have measured the efficiency of the type 410 steering gear submitted by the Adamant Engineering Co., and attach a print of the curves obtained. This steering gear has the characteristic that the efficiency falls as the time interval after the application of the load increases. This is presumably due to the oil on the plain thrust faces of the roller followers becoming squashed out and allowing metal to metal contact. The time required for the efficiency to reach its lowest value was about 5 secs. Under these conditions the roller did not rotate on its bearings, the forward or steering efficiency was less than 50% and the gear was completely irreversible. The figures shown on the attached curves were taken as soon as possible after the application of the load and therefore, represent the maximum efficiency. When the roller follower ceased to rotate on its bearings and slid on the cam the gear squealed as it was turned. The efficiency of the steering gears we are now using is 75 - 85% and does not decrease with time. We consider that if the Adamant steering gear were fitted to a car it would require 40% more effort to steer the car, and would squeal and fail to self centre after a long corner. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} | ||