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 and proposed solutions for unstable steering and springing issues on cars.
| Identifier | ExFiles\Box 28\4\ Scan178 | |
| Date | 8th March 1920 | |
| R.R. 228a (50 T.-S.H. 986. 19-2-0) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2048 x457 Hs.{Lord Ernest Hives - Chair} from EP.{G. Eric Platford - Chief Quality Engineer} c. to BN{W.O. Bentley / Mr Barrington} c. to Da.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} EP{G. Eric Platford - Chief Quality Engineer}7/F8.3.20 X.3441 - RE UNSTABLE STEERING AND SPRINGING. X.1242 X.457 We have been able to carry out tests on the above, and have been able to satisfy ourselves that the steady steering of the car on the road under speed can always be obtained by increasing the backward lean of the pivots. On new cars we find we are able to go up to ½" pivots, without causing any steering wobbles. Further increase in this lean, however, causes the wobbles to become noticeable. As regards the friction of the front steering pivots, this enables the lean of the pivots to be slightly more increased before the steering wobbles are objectionable, but this friction causes the steering to be so heavy as to be unsatisfactory. The chief improvement on the steering wobbles is effected by reducing the flexibility of the steering tube. If no springs at all are used, the steering wobbles are hardly perceptible, and the wobbles can be reduced by increasing the load on the ball ends, which is achieved by increasing the strength and reducing the movement of the springs. Tests were made with a single spring at each end, as suggested by Mr. Royce, but this did not materially show any advantage so long as the load on each ball was the same as that obtained by the double springs, an improvement being effect only when the load on the balls was increased. I consider we should act very quickly with reference to attention to our present cars to overcome the complaint, and I should be glad if you will consider the standardising of increased lean on front pivots simultaneously with increasing the strength and reducing the movement of the springs in the steering connecting tube. We suggest that the present standard lean of ⅛ to 3/16" should be altered to ⅛ to ⅜", variations being allowed in the packing sones to obtain this lean according to the size of tyres which may be used for the front and rear, it being essential that this lean should be obtained with the car in its normal running conditions. If we are to obtain this lean by taper packings, it will be necessary for the taper packings to be permanently fixed to the axle so that they cannot be fixed the wrong way round contd. | ||