The chief characteristic or principle of this engine is the maintenance of
an accurate steam and mechanical balance and the avoidance of cross
pressure. The power is applied directly to the work, the only friction
being that of the steel shaft in phosphor-bronze bearings. Referring to
the cuts, Fig. 1 shows the engine and an electric dynamo on the same
shaft, all connecting mechanism being done away with, and pounding
obviated. There are but two parts to the engine (two disks which supply
the place of all the ordinary mechanism), both of which are large, solid,
and durable. These disks have a bearing surface of several inches on each
other, preventing the passage of steam between them--a feature peculiar to
this engine. Fig. 2 represents an end elevation partly in section, showing
the piston, A, and the abutment disk, B, in the position assumed in the
instant of taking steam through a port from the valve-chamber, E. Fig. 3
is a vertical section through the center of Fig. 2, showing the relations
of the disks, C, and the abutment disks, B, and gear. The piston disks and
gear are attached to the driving shaft, H, and the abutment disks and gear
are attached to the shaft, K. These shafts, H and K, as above stated, run
in taper phosphor-bronze bearings, which are adjustable for wear or other
causes by the screw-caps, O. The whole mechanism is kept rigidly in place
by the flanged hub, r, bolted securely to the cylinder head, F. These
flanged heads project through the cylinder head, touching the piston disk,
and thereby prevent any end motion of the shaft, H, or its attachments.
The abutment disks and shaft are furnished with similar inwardly
projecting flanged hubs, which are provided with a recess, I, Fig. 2, on
their periphery, located radially between the shaft, K, and the clearance
space, J. Into this recess steam is admitted--through an inlet in the
cylinder head not shown in the cuts. By this means the shaft, K, is
relieved of all side pressure. The exhaust-port, which is very large and
relieves all back pressure, is shown at D. The pistons and disks are made
to balance at the speed at which the engine is intended to run. The
steam-valve, for which patent is pending, is new in principle. It has a
uniform rotating motion, and, like the engine, is steam and mechanically
balanced. The governor is located in the flywheel, and actuates the
automatic cut-off, with which it is directly connected, without the
intervention of an eccentric, in such a way as to vary the cut-off without
changing the point of admission. By this means is secured uniformity of
motion under variable loads with variable boiler pressure. It also secures
the advantage resulting from high initial and low terminal pressure with
small clearances and absence of compression, giving a large proportionate
power and smooth action.
Expansion has been excellently provided for, the steam passing entirely
around before entering the cylinder. These engines are mounted on a
bed-plate which may be set on any floor without especial preparation
therefor. The parts are all made interchangeable. A permanent indicator is
provided which shows the exact point of cut-off. The steam-port is
exceptionally large, being one-fourth of the piston area. Reciprocating
motion is entirely done away with. The steam is worked at the greatest
leverage of the crank through the entire stroke. Among the other chief
advantages claimed for this engine are direct connection to the machinery
without belts, etc., impossibility of getting out of line, uniform crank
leverage, capacity for working equally well slow or fast, etc. It has but
one valve, which is operated by gear from the shaft, as shown, traveling
at one-half the velocity of the piston.
[Illustration: Fig. 1.--THE HARRINGTON ROTARY ENGINE COUPLED TO A DYNAMO.]
With this engine a speed of 5,000 revolutions per minute is easily
attainable, while, as a matter of fact and curiosity, a speed of 8,000
revolutions per minute has been obtained. An engine of this class was run
at the Illinois Inter-State Exposition at Chicago for six weeks at a
uniform speed of 1,050 revolutions per minute, furnishing the power for
twenty-three electric arc lights, with a steam pressure not exceeding
fifty-five pounds per square inch, and cutting off at from one-tenth to
one-sixth of the stroke. It was taking steam from a large main-pipe, so
there was no opportunity for an exact test of the amount of fuel used, but
from a careful mathematical calculation it must have been developing one
horse-power from three pounds of coal.
The inventor claims that, as his engine works the steam expansively, even
better results would have been obtained had the engine been furnished
steam at 100 pounds per square inch.
[Illustration: Figs. 2 and 3.--DETAILS OF HARRINGTON ENGINE.]
The Harrington Rotary Engine Company, 123 Clinton Street, Chicago, are the
owners and manufacturers.
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In a can of peas sold in Liverpool recently the public analyst found two
grains of crystallized sulphate of copper, a quantity sufficient to
injuriously affect human health. The defendant urged that the public
insisted upon having green peas; and that artificial means had to be
resorted to to secure the required color.
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