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).
Investigating the causes of high-speed steering wobbles.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan242 | |
| Date | 12th June 1925 | |
| R.R. 493A 150 IT (D.D. 31, 12-6-25) J.H.D. EXPERIMENTAL REPORT. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. to CJ. BJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} EY. c. to Wor.{Arthur Wormald - General Works Manager} Expl. No. REF: HJS/MMB/L.2515. 9.25. HIGH SPEED STEERING WOBBLES. 4457 48810 Our tests running the front wheels of the car on drums have enabled us to ascertain the following. Previously we have been unable to find out. (a) What causes the period of the wobble to coincide with the period of a wheel revolution when it starts, the wheel being balanced statically. (b) What feeds the wobble once it has started, and makes it build up to the alarming proportions experienced. (c) What the true value of the gyostatic couple is in causing the wheels to turn in and out. In connection with point (a), we balanced the wheels statically and then ran them at slow speeds on the drum so that the centrifugal effects of any dynamic put of balance would be negligible. We observed that the axle moved up and down an appreciable amount with a frequency corresponding to the wheel revs. This was due, we believe, to the tyre being eccentric with the rim. Each tyre had a spot on it where the axle was raised. When these two spots were in step the axle moved up and down with a parallel motion. When out of step, with a criss cross motion. We placed an indicator on the spring pad and slowly rotated the wheel. We found that on one side of the tyre the axle was raised .060" higher than on the other side. This was less than contd :- | ||