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Calculations for alterations to Peregrine brakes to align them with the 20/25 HP model.


Identifier  ExFiles\Box 1\10\  B001_X106 TO X 110-page012
Date  7th November 1932
  
γ 106.

For Files.

7.11.32.

ALTERATIONS TO PEREGRINE(Experimental Bentley car never produced / Aero Engine) BRAKES TO BRING IN TO LINE
WITH 20/25 HP.

Built to N.Sch. we have :-
Peregrine(Experimental Bentley car never produced / Aero Engine) 220 Direct + 193 S to rear + 301 S to front.
20/25 HP. 377 " + 220 S to rear + 304 S to front. (S= Servo multiplication of Torque)

The angular movement of the scissor lever is 1.2 x on Peregrine(Experimental Bentley car never produced / Aero Engine) the 20/25HP figure for a given movement of the rear shoes.

The relative brake areas are :-

20/25 HP. Peregrine(Experimental Bentley car never produced / Aero Engine).
Rear 88 sq.ins. 95 sq.ins.
88 sq.ins./ton 130 sq.ins./ton

For the same period between adjustment as the 20/25 HP

The direct braking should be on Peregrine(Experimental Bentley car never produced / Aero Engine) :

377 x 130/88 = 550 units.

The lever ratio of servo to direct should be :-

524/377 x 1/1.2 = 1.13

. . . Servo braking must be 550 x 1.13 = 622 S units. To get 45% front braking this should be split up into 400 S to front and 220 S to rear.

To get these braking units we must :-

(1) Alter 2.750 lever G.100533 to 3.14
(2) " 1.625 levers G.100528 to 1.23
  
  
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).


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