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 wear in oil pump gears due to lack of lubrication and proposed solutions.
| Identifier | ExFiles\Box 149\2\ scan0176 | |
| Date | 27th January 1938 | |
| ST.{Capt. P. R. Strong} c to Rm.{William Robotham - Chief Engineer} c to HHG. 1265 Hd{Mr Hayward/Mr Huddy}/SB{Mr Bull/Mr Bannister}2/HR.27.1.38. Rm{William Robotham - Chief Engineer} says please bin to Wraiths re OIL PUMP GEARS. ------------------- The bearings of all our present oil pump gears wear very badly. This makes a repair impossible as it means new gears and a new casing, which amounts to a new pump. The trouble is due to lack of lubrication of the bearings, all the oil apparently being evacuated by suction. This wear is noticeable on any Bentley or 20/25 HP., resulting in noisy pumps. It is now evident on the large capacity pumps we are fitting to the Bentley. For instance, we have dismantled the oil pump from B.31-CW. owing to a complaint of noise. This was fitted new in September last, and has run only a few thousand miles. We suggest drilling an oil hole from the bearings to the gear to balance the pressure and provide a path for oil. This was done on the Phantom II with very good results. To illustrate this we send you herewith:- 1. The lower casing and two gears removed from the large capacity pump ex B.31-CW. 2. A driving gear and lower casing removed from a 20/25 HP. car. The bearings on this are very bad. 3. An oil pump gear removed from a Phantom I. This is very bad. Any Phantom I oil pump will look like this when dismantled. 4. A gear removed from a Phantom II., mileage over 60,000. This is in excellent condition, being the only type on which the oil holes have been tried. All gears of this type are good when dismantled. We further suggest a scheme to grind the ends of worn gears and fit pressed-in bushes to the casings so as to reclaim worn pumps instead of scrapping them. -continued- | ||