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).
Excessive backlash and wear found in the timing gears of a PH. III Chassis 35 EX. Unit No. 9.
| Identifier | ExFiles\Box 92\3\ scan0069 | |
| Date | 5th January 1937 | |
| Handwritten: Mr Swoll - See me. This is rather serious. Rm{William Robotham - Chief Engineer} Handwritten: 300a To Rm.{William Robotham - Chief Engineer} from HPS{Horace Percy Smith - Experimental Factory Mgr}/RH.{R. Hollingworth} c. to HPS.{Horace Percy Smith - Experimental Factory Mgr} PH. III CHASSIS 35 EX. UNIT No. 9. On dismantling the timing gears of the above unit, it was found that an excessive amount of "backlash" existed between the idler gear, E.87346, and its mating gears. The "backlash" which was in excess of .020", was reduced to normal (.002" - .004") when a new gear was fitted, proving that all the wear had occurred in the idler gear. The latter was fitted on 11.9.36, and since then has completed 6,570 miles road-work, most of which was between Derby and London and in London traffic. Attention is drawn to the fact that a similar case occurred on Ph. III Unit No. 10 and was reported in memo RHC{R. H. Coverley - Production Engineer}/RH.{R. Hollingworth}2/AP.9.11.36. There are indications that the bedding of the teeth has not been uniform, thus giving rise to rapid wear locally. In view of the relatively small mileage and the light work undergone in this particular case, we consider that the matter merits attention. R.{Sir Henry Royce} Hollingworth. | ||