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).
Causes of and potential solutions for heavy steering.
| Identifier | ExFiles\Box 180\M3\M3.2\ img025 | |
| Date | 1st March 1925 | |
| EAGLE STEERING COMPANY Copy to - [REDACTED] HS.{Lord Ernest Hives - Chair} HB{C. E. Harcombe}/M23. 3. 25. Y8430 Y444 STEERING. Regarding heavy steering when standing this has been tested, not to be the different front axle, but there still is the difference of weight and position of the RAC. box affecting the levers. We may examine also the cross steering tube which in our case may give a quicker movement on one lock to the most remote wheel. The Hispano type of box is less desirable than ours and would have more friction and slacks, but it has the one advantage of the nut driven levers remaining the same effective length while the pendulum lever shortens. This gives quicker steering, say 10%, in the centre, but we should not like to change. I think it is possible that the relative movement of the road wheels to the movement of the steering wheel at one or both extreme positions, combined with the extra weight on the RAC. front axle, is the cause of the extra heavy steering at large angles. (I now understand that bolting the 2 arms together has done very little to cure the fault: this was reported as a cure.) I certainly think that a slower worm should be adopted, quite as slow as the Hispano, and this should be confirmed by experimental measurement on the movement of the road wheels to the movement of the steering wheel, on a car, and not theoretically, as some slip may occur. If we can make the whitemetalled nut safe by making the thread in strong bronze very slack, tinning the same and heating, and running in the tin babbitt on the worm we may get a nut and worm less liable to suffer from squeezed out lubricant. As the steering seems too easy at speed and too liable to work loosely, it would seem that a plain thrust both sides is required. I do not think this friction would be noticed, it seems small compared with lifting the front of the heavy car, which gets increasingly rapid as the lock increases, especially in rate of lift per degree of angle of the steering wheel. Let us also remove every ounce of weight we possibly can from the front wheel, the flywheel and clutch being the first things to reduce. I cannot believe there is any binding in the box; nothing has been found in the efficiency test, which can be repeated, also Mr. Day's fig. 3. - 'Support of the box' - can be tried. The 3 short roller bearings might be adopted which should certainly put to rest any doubt of friction in the pendulum lever shaft. I understand we have adopted the longer worm so that the nut does not get partly off the worm on the extreme locks. It will be as well to keep the full area of surface at the ends for the sake of the lubrication and strength. You can use either my idea of forging one lever on the pendulum lever shaft, or Mr. Day's scheme of central flange with 2 levers exactly alike bolted to it. Whichever is considered the quicker and better to get going; both seem equally good. R.{Sir Henry Royce} | ||