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).
Technical report on comparison tests and issues with an independent front wheel suspension system, specifically regarding pitching and buffer springs.
| Identifier | ExFiles\Box 154\1\ scan0091 | |
| Date | 26th January 1934 | |
| To Eg. from Hs{Lord Ernest Hives - Chair}/Les.{Ivan A. Leslie} C. to Wor.{Arthur Wormald - General Works Manager} C. to R.{Sir Henry Royce} C. to Hy.{Tom Haldenby - Plant Engineer} C. to Ds. C. to Hdy.{William Hardy} x3873 INDEPENDENT FRONT WHEEL SUSPENSION - 27-EX. ---------------------------------------- The present state of our scheme is a long way from being satisfactory. The only noticeable improvement over our standard cars is slow up and down movement of the front of the car. The front of the car has a periodicity of 73 oscillations per minute, whereas our standard car is about 100. The periodicity of the back of our independently sprung car is 70 per minute. SPRINGING. Comparison tests have been made against a standard car. Both cars had dampers disconnected. On fairly good surface straight roads the riding qualities of the independent suspension is considerably superior than a standard car. However, as soon as a bump is reached the car commences to pitch. This is due to the moving member coming on to the buffer spring. There is not nearly enough movement on the main spring before the buffer spring is reached. This effect is observed also when driving the car normally with the dampers working. The car is continually being excited into a state of pitching due to hitting the buffer springs. Whenever a bad bump is hit the harshness is transmitted to the car from the buffer spring. Pointers were fitted to the suspension as Fig.I so that the position of the moving member could be realised whilst driving the car. On the dials behind the pointers marks were made showing when the moving members came on to the buffer springs and then on to the stops. From this the following was observed. When a sharp left-hand corner was taken, the offside wheel went on to the bump buffer spring and the nearside wheel on to the rebound buffer spring. On right-hand bends the wheels moved on to the other buffer springs. In consequence when a small bump is crossed whilst cornering, the harshness from the buffer spring is felt in the car, and pitching follows. We intend to remove all buffer springs and increase the movement before the stops. Buffer springs can be added later if it is found possible to use them. At the movement we hit the wings on this car, so when the buffer springs are removed we cannot use the existing | ||