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).
The functions and advantages of the Andrade Differential.
| Identifier | ExFiles\Box 2\6\ B002_X 140 141 157-page108 | |
| Date | 27th March 1928 guessed | |
| The functions of the Andrade Differential are as follows: When there is ice or snow on the road, it often happens that the car with the old fashioned geared differential will stall, with one rear wheel standing still, and the other wheel spinning. This is a physical impossibility with the Andrade Differential, because both of the rear wheels must rotate as fast as the master gear over the Andrade Differential. The result is that in the last five years with over seventy cars and trucks with the Andrade Differential in them, not one of them has ever stalled, even under the worst ice and snow conditions, when any number of other cars and trucks were stalled. Another function of the Andrade Differential is to largely eliminate skidding when a car or truck is running under power. The reason for this is that the instant the car starts to skid say to the right, all the power of the engine is automatically put on the right hand rear wheel by the Andrade Differential, and the left hand rear wheel has no power whatever. The result is that the skid instantly ceases. If the car or truck then starts to skid to the left, all the power of the engine is automatically put on the left hand rear wheel by the Andrade Differential, and the right hand rear wheel has no power whatever. This instantly ends the skid. Of course when the car is going forward without a skid, the engine power is automatically applied to both of the rear wheels by the Andrade Differential. Even if one of the rear axles should break, or if one of the rear wheels should become loose and rotatable over its axle, the Andrade Differential will automatically put all the engine power on the sound rear axle, and thus bring the car home. This actually happened in one of the cars way off in the country with the Andrade Differential in it, and this car was run over 25 miles to the garage. Of course if this had happened in any car with the old fashioned geared differential in it, that car would have had to be pulled home by another car or truck. | ||