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).
From F.H.R. to Claude Johnson discussing the design and materials for worm gears.
| Identifier | ExFiles\Box 2\6\ B002_X 140 141 157-page208 | |
| Date | 23th April 1912 | |
| For T.C. & Mr Wormald Le CanadelHenry Royce's French residence Mr Claude Johnson from F.H.R. Worm Gear 1. Very desirable for low gear. 2. Bevels are, I believe, increasingly difficult with increased ratio, but Mr Wormald seems to think that no greater trouble was experienced with 22T than with 24 and 26. 3. Surprised that Lanchester worm is not better than ours because I think ours can be improved. We should try a metal for worm wheel less liable to seize than we have done; I don't think Lanchester has the best material for the worm wheel. The Hindley form of worm gear should have a tooth form equal to an annular wheel in Hollow faces. Copper worm wheel fed with grinding material should bring the worm to better shape than anything and be equal to the shape produced by long wear. It is important to get the worm correct, the wheel will wear and bed itself wherever possible, this possible area of contact with the worm increases with wear of the worm. We shall probably not get very good form until we hob the wheel with as near as practically an exact duplicate of the worm; and also hob the worm with a worm wheel. Many thanks to Mr Whitehead, his suggestions | ||