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).
Empirical formula and data table for calculating crankshaft stiffness in bearings.
| Identifier | ExFiles\Box 6\1\ 01-page089 | |
| Date | 23th November 1927 | |
| TITLE: SUGGESTED EMPIRICAL FORMULA FOR CRANK SHAFT STIFFNESS IN BEARINGS FORMULAS: EQUIVALENT LENGTH FROM A TO B IN TERMS OF JOURNAL SHAFT e = (2b + 0.6h) + (3/4) * ((d2^4 - d1^4) / d2^4) * a + (3/h) * (π/w) * (r^4 / d2^4) e / d2 = P + Q + R STIFFNESS FROM A TO B = GJ / e WHERE G = 11.8 x 10^6 FOR STEEL J = (π/32) * (d2^4 - d1^4) DRAWING LABELS: 'A', 'B', 'w', 'r', 'b', 'a', 'b', 'h', 'd1', 'd2'. EQUIVALENT LENGTH e EQUIVALENT LENGTH L FROM TEST TABLE DATA: | No | d2 | r/d2 | b/d2 | a/d2 | h/d2 | w/d2 | P | Q | R | e/d2 | L/d2 | RATIO e/d2/L/d2 | TEST STIFFNESS x 10^6 LBS INS PER RAD | REMARKS | |------|-------|-------|--------|--------|--------|--------|-------|--------|-------|-------|-------|-----------------|---------------------------------------|--------------------------------------------------------------------------------| | 1M | 1.656 | .868 | .49 | 1.0 | .49 | .529 | 1.13 | 1.51 | 1.448 | .854 | .727 | 3.03 | 3.194 (.992) | 1.064 x 1.55, SCALE MODEL OF A MARINE ENGINE SHAFT | | 2M | 9.453 | .876 | .456 | 1.0 | .456 | .521 | 1.167 | 1.055 | 1.407 | .875 | 2.02 | 2.88 | 3.12 (1.0) | 1.082 x 300, EXAMPLE GIVEN BY PROF. LEWIS SOC: NAVAL ARCHITECTS & MARINE ENG: VOL.33.1925 (NEW YORK) | | 3M | 1.5 | .896 | .541 | 1.0 | .541 | .5055 | 1.01 | 1.33 | 1.402 | .738 | 1.057 | 3.22 | 3.104 (.967) | .904 x 1.15, SCALE MODEL OF A MARINE ENGINE SHAFT | | 4M | 11.22 | .931 | .451 | 1.0 | .461 | .5065 | .457 | 1.126 | 1.648 | 1.35 | .545 | .653 | 2.88 (3.05) 1.0 | 1.059 x 512, EXAMPLE GIVEN BY PROF. LEWIS | | 5M | 7.0 | 1.0 | .464 | 1.0 | .464 | .5715 | .571 | 1.14 | 1.571 | 1.6 | .897 | .672 | 3.13 (2.93) 1.17 | .936 x 129.4, EXAMPLE GIVEN BY PROF. LEWIS | | 6A | 2.875 | .626 | .587 | .933 | .652 | .163 | .624 | .892 | 1.022 | .664 | 1.044 | 2.425 | 4.13 (4.33) .477 | 1.048 x 5.8, AIRCRAFT ENGINE | | 7A | 2.324 | 1.1 | .645 | .548 | .538 | .406 | .322 | 1.015 | 1.22 | 1.072 | 1.452 | 2.32 | 4.844 (4.34) .592 | .898 x 2.76, AIRCRAFT ENGINE | | 8A | 5.0 | 1.2 | .65 | .85 | .5 | .3 | .32 | .66 | 1.19 | .857 | .884 | 2.742 | 4.48 (4.175) .455 | .932 x 28.5, AIRCRAFT ENGINE | | 9A | 2.92 | 1.28 | .714 | .99 | .754 | .341 | .3 | 1.01 | 1.145 | .922 | .88 | 3.152 | 4.954 (5.08) .452 | 1.025 x 4.2, AIRCRAFT ENGINE | | 10A | 2.625 | 1.33 | .524 | .905 | .477 | .381 | .382 | .952 | 1.282 | 1.068 | 1.062 | 2.43 | 4.89 | AIRCRAFT ENGINE | | 11A | 5.15 | 1.528 | .687 | 1.032 | .687 | .428 | .419 | 1.01 | 1.298 | 1.19 | .647 | 1.943 | 3.78 (4.07) .664 | 1.075 x 30.25, AIRCRAFT ENGINE | | 13C | 2.625 | 1.047 | .5714 | .5095 | .4285 | 2.857 | .4095 | .7047 | 1.152 | .899 | 1.193 | 2.245 | 4.337 (4.5) .488 | 1.038 x 4.17, MOTOR CAR ENGINE | | 14C | 2.0 | 1.125 | .625 | .75 | .375 | .2225 | .4 | .75 | 1.1 | .845 | 1.605 | 2.681 | 5.131 (5.5) .377 | 1.07 x 1.425, MOTOR CAR ENGINE | | 15C | 2.125 | 1.058 | .5882 | .7059 | .3529 | .2352 | .4235 | .6353 | 1.094 | .81 | 1.803 | 2.526 | 5.139 (5.7) .343 | 1.108 x 1.718, MOTOR CAR ENGINE | | 16C | 2.0 | 1.125 | .625 | .75 | .4375 | .2625 | .375 | .725 | 1.125 | 1.047 | 2.678 | 5.975 | 6.75 (.2962) 1.13 | 1.163, MOTOR CAR ENGINE | | 17C | 1.89 | 1.353 | .423 | .937 | 0 | .544 | .4067 | 2.592 | 1.248 | 1.41 | 2.432 | 2.522 | 6.364 (5.78) .776 | .91 x 1.307, ...SPECIAL CASE G CRANKS & BEARINGS CALCULATION APPLIED TO CRANKS IN PAIRS | | 18C | 2.295 | 1.047 | .6675 | .714 | .429 | .2857 | .373 | .7025 | 1.219 | .871 | 2.025 | 1.883 | 4.783 (4.830) 5.360 1.015 | 3.485, SPORTS PHANTOM E 76548 | | 19C | 2.125 | 1.058 | .648 | .707 | .4115 | .2705 | .343 | .702 | 1.270 | .8175 | 1.99 | 1.86 | 4.615 | INDIA 6 LEC 2450 CALC. STIFF: 1.985 x 10^6 PER CRANK | STAMP: Rolls-Royce Limited DERBY AERO-ENGINE DEPT. RECEIVED 23 NOV 1927 | ||