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).
Comparing the performance and noise levels of helical gears versus straight spur gears.
| Identifier | ExFiles\Box 55\1\ Scan137 | |
| Date | 13th February 1932 | |
| N/S. N'by/Day/ By.{R.W. Bailey - Chief Engineer} Sq. mtr. FR Rg{Mr Rowledge} & RHC{R. H. Coverley - Production Engineer} Gear Box. x5992. LC. S.A.H. Unless I have lost my perceptions. The 3rd speed & idling on this car has improved immensely by removal of helical gears. Showing as one can imagine that helical gears do not wear noisy as may happen often. Straight spurs which I have observed first become more silent then wear noisy, worse as time goes on. Where as the helical gears in the few cases I have known seem to go on improving, this might be tested out to find if it is true. "There seems little doubt that we can call these easy change & silent 3rd quite equal to what one would expect even from R.R. R.{Sir Henry Royce} | ||