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).
Design and challenges of an independent torsion bar suspension for a Bentley.
| Identifier | ExFiles\Box 87\4\ scan0135 | |
| Date | 29th August 1936 | |
| Handwritten: les - Is the additional complication justified? Are we really tied up for and wor.{Arthur Wormald - General Works Manager} from E.{Mr Elliott - Chief Engineer} with stresses Om. x v l o Typed: c. Hs.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} SECRET. FILE ONLY Independent Suspension - Bentley. We are making good progress with the design of the Bentley independent torsion bar springing. From other peoples experience with this system there appears to be a difficulty in obtaining a low enough rating for the spring without running into excessive stresses. This difficulty is not so great in our case owing to the proportions of the linkage we are using requiring less angular movement from the spring. These proportions are based on our Phantom III experience and are suited to the dimensions of the car. In this design it has occurred to me that we could make the upper linkage pivot tubular and bring the spring through the centre with an anchorage at the front end having a differential splined coupling. We find this has a number of advantages, an important one being its effect in lengthening the spring and reducing the maximum stress and stress range. It also renders the spring very accessible for assembly and withdrawal, and provides an easy method of adjusting the initial position of the ride, and also readjusting for spring settling. The general scheme of construction has been arranged in such a manner that the suspension and its mechanism is an independent unit which could be practically bolted to the present frame. This would not however make the best job, and we should want to extend the side channels more or less parallel from the dash to where they join on to the suspension. We have prepared a scheme for adequately stiffening up the frame without interfering with the rear part of the chassis or coachwork at all, as we are of the opinion that independent suspension with low rating springing demands this feature. E.{Mr Elliott - Chief Engineer} | ||