Rolls-Royce Archives
         « Prev  Box Series  Next »        

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).
The mechanical efficiency of a car's braking system.

Identifier  ExFiles\Box 73\2\  scan0140
Date  12th December 1923
  
R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary}

EXPERIMENTAL REPORT.

Expl. No. 9940
REF: UG/AJH/12.12.23.

[Diagram of a braking system linkage]
FRONT BRAKE EQUALISER (LOCKED)
PRESSURE DISTRIBUTOR (SERVO CONNECTION LOCKED)

ω = pressure applied at brake cam levers on front brakes (equivalent to ω/2 lbs. at each cam lever).
W = pressure at pedal lever on distributor overcome by ω
Leverage on this car found to be as 1 : 1.45 (i.e. W x 1 = ω x 1.45).

These tests are the converse of tests on page 1.

| W lbs. | ω lbs. | Theor: ω = (W x 1.45) | Loss to friction. | Mech. efficy: |
|---|---|---|---|---|
| 57 | 50 | 82.65 | 25.65 | 60.5% |
| 78 | 75 | 113.1 | 38.1 | 66.2% |
| 98 | 100 | 142.1 | 42.1 | 68.3% |
| 128 | 125 | 185.6 | 60.6 | 68.7% |
| 145 | 150 | 210.25 | 60.25 | 71.3% |
| 172 | 175 | 249.4 | 74.4 | 70.3% |
| 198 | 200 | 287.1 | 87.1 | 69.8% |
| 226 | 225 | 327.7 | 102.7 | 68.75% |
| 250 | 250 | 362.5 | 112.5 | 69% |
| 273 | 275 | 395.85 | 120.85 | 69.7% |
| 297 | 300 | 430.65 | 130.65 | 69.7% |
| 320 | 325 | 464 | 139 | 70.25% |
| 333 | 350 | 482.85 | 132.85 | 72.5% |

Mechanical efficiency (average).
= 68.4%
  
  


Copyright Sustain 2025, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙