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).
Letter from engineer B. Vallance responding to queries on a freewheel gear design.
| Identifier | ExFiles\Box 136\4\ scan0047 | |
| Date | 27th April 1931 | |
| (2061. B. VALLANCE, ENGINEER. 52, Southbourne Grove, Westcliff-on-Sea. SPECIALIST IN AERIAL ROPEWAYS. CONVEYORS, ETC. Messrs Rolls-Royce, Ltd Derby Expl. Dept April 27 1931 Dear Sir In reply to your queries,- (1) I do not think the gear if designed for 200 H.P. would be larger in the ratio of 200 to 30, as with large gears, it would be preferable to use more than 4 rollers for driving. If 8 were used, 2 would always be in action at the same time, and consequently, the pressure being divided, the gear would be larger in the ratio of 100 to 30 (2) If the gear were designed for a 1 to 1 top gear, it would be best to reverse the arrangement shown on the drawings. That is - make neutral or zero position that when the spherical member was in its maximum angular position, and top or 1 to 1 position when there was no angle. By this arrangement a direct drive could be obtained on top and the freewheels would not be in action at all. Otherwise I do not think the roller bearing would be noisy, they were not so in the model. Whether the freewheels would be noisy is open to question. I have considered the use of silencing springs for the pawls.. (3) The maximum thrust is constant on each roller while it is working during the 1/4 rev. of the driving shaft, but the drive on these rollers overlaps, that is, - 2 rollers are actually in action at the beginning and end of the stroke, thus there is no shock of impact possible on these rollers. There would not be in any case, as the torque is constant and there is not any impulsive load on the rollers. The freewheels come into engagement only when the two members are rotating at the same speed. (4) The gear as designed is definitely a freewheel gear, and I do not see any way at present of doing without the freewheels. They could however be looked under the conditions of 1 to 1 as mentioned in (2). I shall be very pleased to give you any further information It is not too easy to follow the action of the gear. I was months before I began to see what was happenning. Yours faithfully B. Vallance | ||