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 testing of a low-cost American gearbox fitted with a spool gear third speed.
| Identifier | ExFiles\Box 182\M19\ img051 | |
| Date | 19th March 1931 | |
| To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to Da.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair}3/WJ.19.3.31. X3720. X2061. TESTS ON AMERICAN GEARBOX FITTED WITH SPOOL GEAR THIRD SPEED. You will remember that Oy. arranged for Mr. Keracher of Detroit to send us a gearbox which we could, if we wished, try on one of our cars. The box arrived some time ago. It was inspected by Derby and V.W.. The design is crudely simple and cheap for production. This gearbox is supposed to cost thirty dollars. We have fitted this box to one of our 25 HP. cars and the third spool gear is remarkably silent, much more silent than anything we can approach. It is also definitely more silent than the double Helical third speed and also the Daimler epicyclic. The side shaft gears with the engine idling are wonderfully quiet. In this respect it is very much better than a Helical gear with the Maybach jaws judging by the standard both on the Maybach car and our own car. It is also more silent than the Epicyclic. On this box they had fitted Maybach jaws for the top gear, as they are arranged they are not a success. Apart from the disadvantage of having the neutral position the angles on the jaws are too steep which made them difficult and noisy to engage. This scheme does not appear to have been adopted on any of the american cars. Withall the different schemes of silent gears we have tried without a doubt the spool gear, from results, is number (1) for silence. We have no first hand experience as regards its reliability. This would have to be carefully gone into because we understand that on the latest Graham Paige cars they are going to the helical third speed. In this case it may be cost which is influencing them. Hs.{Lord Ernest Hives - Chair} | ||