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).
From 'R.' proposing a trial for an 'interlaced 6 throw crankshaft' design on a P.V. 12 cylinder aero engine.
| Identifier | ExFiles\Box 14\2\ Scan089 | |
| Date | 1st December 1930 | |
| RG.{Mr Rowledge} HS.{Lord Ernest Hives - Chair} } FROM R.{Sir Henry Royce} BY.{R.W. Bailey - Chief Engineer} EFC. } X7015 RL/M1.12.30. Copy to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} INTERLACED CRANKSHAFTS. X.8010 X.5010. X.634. Some time ago I schemed what we termed the interlaced 6 throw crankshaft. This is not the full zigzag but a compromise to avoid balance weights etc. It still leaves each 6 cyl. engine with 3 thress interwoven but each of the alternative cylinders are spaced unevenly. This arrangement of crankshaft has however many advantages over the present standard. In the case of the 12 cyl. engine the impulses are as at present and the disadvantage is not nearly so great as in the 6 cyl. engine. In the case of the 6 cyl. engine the over-running vibrations are non-existent as the kinetic energy in the pistons is quite even, but I fear the impulses are too unevenly spaced to be practicable, being 60 and 180 degree intervals. In the case of both 6 and 12 cyl. engines the crankchamber stresses are so much reduced that the trouble from this cause should be almost non-existent. Although some of the bearings are nearly as heavily loaded, the distance apart of these bearings and the direction of the stresses is such that the maximum crankchamber bending stresses are reduced to perhaps one quarter. Although I expect we shall be disappointed with the result I think the scheme is worthy of a trial as we can-not really tell the effect until we have tested it. It will be found that the camshaft is much smoother to drive because the cams are more evenly distributed. We propose trying this as an alternative on the small P. V.{VIENNA} 12 cyl. aero engine now nearing completion. R.{Sir Henry Royce} | ||