Rolls-Royce Archives
         « Prev  Box Series  Next »        

Diagram and chart analyzing a modified braking system's efficiency and distribution.


Identifier  ExFiles\Box 105\4\  scan0015
Date  17th June 1925 guessed
  
INDIA(Production 20 HP. with 4-speed box and Front Wheel Brakes)
MS4 / LG 20525 AS MODIFIED BY N.SCH. 2005 & DAI / M 9625

DIAGRAM TEXT & VALUES:
DRUM DIA. 13"
.5 CAM
3.35
2.25
1.35
13.0°
4.35
1.187
1.350
2.00
2.150
4.00
4.875
1.850
2.150
2.00"
3.150
6.00
DRUM DIA. 14"
.43 CAM
2.50
2.30"

BRAKING CALCULATIONS:
DIRECT REAR BRAKING
13 / 4.35 = 1.187 / 1.350 * 2.000 / 3.150 * 6 / 2.3 * 2.5 / 43 = 14 P. = 355 P.

SERVO REAR BRAKING
S * 13 / 4.35 = 1.187 / 1.350 * 1.850 / 1.750 * 4.875 / 8.000 * 2.150 / 3.150 * 213 P = 249 S.P.

SERVO FRONT BRAKING
S * 13 / 4.35 = 1.187 / 1.350 * 1.850 / 1.750 * 4.875 / 8.00 * 2.15 / 2 * 145 P = 266 S.P.

DISTRIBUTION FOR VARIOUS SERVO EFFICIENCIES.

TABLE:
SERVO TORQUE MULTIPLN | FOOT RATIO TO REAR | SERVO TO REAR | TOTAL TO REAR | SERVO TO FRONT. | TOTAL BRAKING | % BRAKING FRONT | % BRAKING REAR.
0 | 355 P. | 0 | 355 | 0 | 355 | 0 | 100 %
.25 | 355 | 62.3 | 417 | 66.5 | 483 | 13.7 | 86.3
.5 | 355 | 124 | 479 | 133 | 612 | 21.6 | 78.4
.75 | 355 | 187 | 542 | 199 | 741 | 26.8 | 73.2
1 | 355 | 249 | 604 | 266 | 870 | 30.6 | 69.4
2 | 355 | 498 | 853 | 532 | 1385 | 38.5 | 61.5
3 | 355 | 747 | 1102 | 798 | 1900 | 42 | 58
4 | 355 | 996 | 1351 | 1064 | 2415 | 44 | 56

CHART TEXT:
INDIA(Production 20 HP. with 4-speed box and Front Wheel Brakes)
ORIGINAL BRAKE LEVERS AS IN MS4/LG 20525.
ALTERED AS PER N.Sch. 2005 & DAI / M 9625.

Y-AXIS (LEFT): CONVENTIONAL BRAKING UNITS.
Y-AXIS (RIGHT): % BRAKING.
X-AXIS: SERVO TORQUE MULTIPLN UNITS

CHART LINES:
TOTAL BRAKING
% REAR BRAKING
TOTAL REAR BRAKING
% FRONT BRAKING
SERVO TO FRONT
SERVO TO REAR

STAMP:
ROLLS-ROYCE LIMITED
DERBY
  
  
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 🗙