Rolls-Royce Archives
         « Prev  Box Series  Next »        

Torsion test results for a 20 HP crankshaft, from the forging stage to the finished shaft.


Identifier  WestWitteringFiles\R\2December1927-February1928\  Scan036
Date  7th December 1927
  
20 H.P. CRANKSHAFT - TORSION TESTS
FORGING TO FINISHED SHAFT

COLUMN HEADERS: OPERATION, 15, 19, 21, 22, 31, 33A, 39A, FINISHED SHAFT

MAIN BEARINGS
No. 1, DIA.: 2.200, =, =, =, =, =, =, 2.000
No. 1, LENGTH: 1.550, =, 1.610, =, 1.540, =, =, 1.525
No. 4, DIA.: 2.200, =, =, 2.030, =, =, =, 2.000
No. 4, LENGTH: 1.500, =, 1.550, =, =, =, =, =
No. 7, DIA.: 2.200, =, =, 2.030, =, =, =, 2.000
No. 7, LENGTH: 1.725, =, =, =, =, =, =, 1.800
Nos 2, 3, 5 & 6, DIA.: 2.375 (F), 2.200, =, 2.030, =, =, =, 2.000
Nos 2, 3, 5 & 6, LENGTH: .650 (F), 1.020, 1.070, =, =, =, =, 1.050

CRANK-PINS
OUTER, INNER DIAMETER: 0, =, =, =, 1.250, =, =, =
OUTER, LENGTH: 1.900 (F), =, 1.625, =, =, 1.530, .750, 1.500
INNER, " ": 0, =, =, =, =, =, =, =
INNER, LENGTH: 1.100 (F), =, 1.480, =, =, 1.490, =, 1.560

NOSE
OUTER DIAMETER: 1.450, =, =, =, 1.420, =, =, 1.400
INNER ": 0, =, =, =, .625, =, =, =
LENGTH: 4.300, =, =, =, 2.520, =, =, 2.500

WEBS
DEPTH OPS 1, 6, 7 & 12: 1.015, =, .805, =, =, .795, =, .790
DEPTH OF 2, 3, 4, 5, 8, 9, 10, 11: 1.200 (F), 1.015, .805, =, =, .795, =, .790
WIDTH: 2.550 (F), =, =, =, =, 2.200, =, =

TEST RESULTS
MEASURED STIFFNESS OF WHOLE SHAFT. LBS. FT./RAD.: 53,000, 41,400, 27,200, 25,600, 22,800, 17,400, 16,400, 15,280 (2 BEARINGS)
∴ STIFFNESS OF ONE WEB WILL BE : LBS. INS./RAD. x 10⁶: 6.08, 4.18, 2.46, 2.33, 2.00, 1.463, 1.365, 1.270
CALC: STIFFNESS ONE WEB. LBS. INS./RAD. x 10⁶: 3.765 (APPROX. VALUES ONLY), 3.39 (APPROX. VALUES ONLY), 2.39, 2.272, 2.205, 1.607, 1.577, 1.46 (7 BEARINGS)
RATIO: CALC: STIFFNESS / TEST STIFFNESS: .620, .811, .971, .9725, 1.103, 1.098, 1.155, 1.15
RATIO: TEST STIFFNESS / FINISHED STIFFNESS: 3.47, 2.71, 1.78, 1.675, 1.49, 1.14, 1.07, 1.0
MEASURED LOSS OF STIFFNESS PER WEB (EACH OP.) x 10⁶: 1.900, 1.720, 0.130, 0.330, 0.537, 0.098, 0.095
CALC. LOSS OF STIFFNESS PER WEB (EACH OP.) x 10⁶: 0.375, 1.000, 0.118, 0.067, 0.598, 0.030, 0.117
RATIO: CALC. LOSS / ACTUAL LOSS: .197, .582, .900, .203, 1.110, .306, .123
  
  
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).


Copyright Sustain 2026, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙