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).
Failure of a Goshawk bevel pinion and proposing design improvements to strengthen it.
| Identifier | ExFiles\Box 49\2\ Scan173 | |
| Date | 12th November 1923 | |
| To DA.{Bernard Day - Chassis Design} from R.{Sir Henry Royce} c. BY.{R.W. Bailey - Chief Engineer} c. to CJ. HS.{Lord Ernest Hives - Chair} EP.{G. Eric Platford - Chief Quality Engineer} SERIOUS AND URGENT. X4256 R2/M12.11.23. RE. GOSHAWK BEVEL PINION. X.4256. The broken pinion clearly shews that there is a nasty sharp corner due to the helical formation of the gear on the leading end of each tooth which on the forward drive is subjected to maximum stress particularly if the load happens to be concentrated at the top of the tooth at that end of the gear. I think the three improvements we have sent by telegram as follows will put up the strength of the pinion very considerably :- (1) Largest radii possible in the bottom corners of teeth., There appears to be almost a sharp corner at present. (2) Increased length of teeth of the pinion (suggested by Mr. Elliott) particularly on the outer end to tail off the stress. (3) Rounding the ends of the teeth by turning to ease off the bending moment on the tooth. Also the air hardening steel, providing a tooth of homogeneous material, should be an improvement if we can use it. (Persevere). Can the pinion be strengthened at the expense of the wheel as in the Reinecker system: probably this has already been done. Always change of stress and sharp corners. R.{Sir Henry Royce} | ||