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).
Steering gear design, addressing road shocks, steering effort, and high-speed wobbles in large vehicles.
| Identifier | ExFiles\Box 178\1\ img102 | |
| Date | 13th July 1926 guessed | |
| - 3 - be increased and the drivers hands move through a larger distance for unit angular displacement of the road wheels. It is obvious that there is a limit to the number of complete rotations of the steering wheel from full lock to full lock for comfortable driving. In practice this is about 2 1/2 turns. When big cars have reached this limit, reasonably light steering can only be obtained by having a very efficient steering reduction gear. As will be seen from future remarks, a highly efficient reduction gear is necessarily a very reversible gear. Reversible steerings are bad for road shocks. Big cars suffer from road shocks more than small cars for reasons subsequently enumerated. Therefore finger-light steering and immunity from road shocks are almost incompatible on a large car. This is one of the problems that has had to be solved on the Phantom. Graph 1 shews clearly the effect of increasing the weight on the front axle of a car, also the result of alteration in tyre pressures. Increased section of a tyre also increases the work to be done steering the car. Recently, all three factors have come into prominence in car design, hence a large number of present-day steering problems. The problem of road shocks has also been aggravated recently by the advent of high speed steering wobbles. There is no doubt that the two are closely connected. More irreversible steer-ings are now demanded in consequence. This means more inefficient reduction gears. There is no leverage to spare to deal with inefficient reduction gears and yet provide light steering. | ||