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).
Crankshaft and bearing lubrication for the Japan III model, detailing issues with oil supply and the proposed remedy.
| Identifier | ExFiles\Box 14\2\ Scan008 | |
| Date | 19th April 1928 | |
| To R from Hs{Lord Ernest Hives - Chair}/ACL. c. to BY.{R.W. Bailey - Chief Engineer} 47010 HS{Lord Ernest Hives - Chair}/ACL1/LG19.4.28. INDIA 111. CRANKSHAFT AND BEARINGS. 45010 We have received Lec. 2545 shewing the arrgt. of the crankshaft and bearings and appreciate the necessity of employing an oil feed to each of the seven journal bearings. We note that there is only one oil hole drilled through the journal when used in conjunction with grooveless bearings, having one feed hole, means that the big end bearings are only once momentarily in direct communication with the main pressure system during one revolution. It is considered that the oil supply to the big end bearings by this method is inadequate because of our experience with the Phantom chassis 12-EX, which was fitted with a similar scheme, and which experienced the failure of a big end bearing. When 12-EX was dismantled there was evidence that all the big end bearings were suffering slightly from inadequate lubrication. This defect was remedied by providing three feed holes in the crankshaft journals of .250" dia. spaced at 120°, Which is the practice adopted on the RR.F. aero engines. The crankshaft of 12-EX now on test in France - was modified in this manner, also stiffer high pressure relief valve spring was fitted which gave an oil pressure of 60 lbs/sq.in. With grooveless bearings on the RR.F. engine we have found it necessary to considerably increase the oil pressure. With the high pressure contd :- | ||