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Unformatted text preview: istons operating on a 2-lobe c am. Its advantages were
its small diameter and a propeller shaft running at half engine speed
w ithout the usual reduction gearing. The only crankless reciprocating
engine to reach the stage of official approval, it received in June 1927
U nited States Department of Commerce Approved-Type Certificate No. 1.
D uring 1926-28 it was flown experimentally, but it proved impractical
because of excessive vibration resulting from torque variation.
F AIRCHILD-CAMINEZ ENGINE. T he earliest development of a sleeve-valve
aircraft engine that I recall was that of the Belgian Minerva, a Knighttype, or double-sleeve, engine which appeared in the 1920s, but never
got beyond the experimental stage. The single-sleeve, or B urt-McCollum,
t ype, was exploited chiefly in England and finally became operational in
t he Bristol line of aircraft radial engines, including the Hercules (fig. 58),
Perseus, and Centaurus. These were used by the Royal Air Force during
W orld War II. The Napier Sabre, also using the single-sleeve valve, was a
24-cylinder, l iquid-cooled, 2-crankshaft H-type engine used in British
fighters toward the end of World War II. The Rolls-Royce Eagle (not to
b e confused with the 12-cylinder E agle of World War I), a 24-cylinder
H -type engine with sleeve valves, was very similar to the Napier Sabre.
S LEEVE-VALVE ENGINES. 57 F igure 5 7.—Fairchild-Caminez
e ngine, transverse section; 135
h p at 1000 r p m , 3 6 0 lb. The
o nly crankless
e ingine to reach the stage of
o fficial approval, it was later
f ound to be impractical because of severe torque variation.
1 929, vol.
2 , p .1112, f i g . 535). F igure 5 8.—Bristol H ercules
7 59 1 4-cylinder s leeve-valve
e ngine, 1 9 5 6 ; 2 0 0 0 hp at 2 8 0 0
r p m , 2 0 6 0 lb. Earlier models
w ere used in British bombers
d uring World War I I . (From
W i l k i n s o n , Aircraft Engines of
the World, 1 954, p. 244) 58 I t was d eveloped after t he war, too l ate t o c ompete with t he r apidly d eveloping j et and t urbine engines.
Diesel engines built by B eardmorc a nd Maybach were used experimentally in some rigid airships during t he 1920s.
T hose used operationally aboard t he Hindenburg a nd its l ittle-known
sister ship, t he Graf ^eppelin II, w ere of D aimler-Benz manufacture. T he
first diesel engine t o p ower a n a irplane was a P ackard air-cooled radial
(fig. 59) designed by L. M. Woolson, w ho was killed in a c rash ( due entirely t o bad w eather) of an a irplane powered with one of these engines
before t he d evelopment was c ompleted. T he P ackard diesel received from
t he Civil Aeronautics Administration a CAB A pproved-Type Certificate
43 on 6 M arch 1930. It set the w orld's nonrefueling duration record for
h eavier-than-air craft 25-28 M ay 1931, a r ecord that still stands. This
D IESEL A IRCRAFT ENGINES. Figure 59.—Packard 4-stroke-cycle 9-cylinder radial air-cooled diesel engine (NASM 1 932-7), 1 928;
225 hp at 1950 rpm,...
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This document was uploaded on 01/19/2014.
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