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).
Testing a crankshaft oiling system using grooveless bearings.
| Identifier | ExFiles\Box 14\2\ Scan009 | |
| Date | 19th April 1928 guessed | |
| contd :- -2- system employing grooveless bearings - like the Curtiss - which we are at present testing on some of the RR.F. engines, we use a somewhat different arrangement of piping in the crankshaft. Referring to the appended sketch we see journals Nos. 2, 4 and 6 are connected by means of oil pipes with the crank pins on either side and these journals are closed with oil caps. Therefore each of these journals supply two crankpins. Because all the crankshaft bearings are grooveless and have only one feed hole through the bottom half it becomes necessary to use three holes drilled through the journals to convey an adequate supply of lubricant to the big end bearings. The big ends are therefore in direct communication with the main pressure supply when these holes register with the feed holes in the crankshaft bearings. The remaining journals - ie. Nos.1, 3, 5 and 7 - have no inserted oil pipes and the oil feed to them is for lubricating these bearings alone, except No.7 which journal is drilled with three holes for lubricating the floating bush. An oil pressure of 100 lbs/sq.in. is used in conjunction with this system. We shall shortly be taking down an engine for inspection fitted with the above oiling system which has completed nearly 50 hrs. running. Our experience with this system has been that the outstanding advantage is in considerably reduced heat to the oil. We will furnish a report when we have completed the tests and inspected the engine. contd :- | ||