Improvements in Compound Steam Engines.
Year: 1892

page_text: Date of Application, 9th Aug., 1892
Complete Specification Left, 5th May, 1893-Accepted, 10th June, 1893
PROVISIONAL SPECIFICATION.
Improvements in Compound Steam Engines.
I, ALEXANDER CARNEGIE KIRK, LL.D., of the firm of Robert Napier and
Sons, of Lancefield House, Glasgow, in the County of Lanark, North Britain,
Engineer, do hereby declare the nature of this invention to be as follows, that
is to say :-
My said invention relates principally to such compound steam engines as are
constructed for ordinarily working with four stages of expansion, and it comprises
improved combinations and arrangements of parts, diminishing vibration and
strains, and possessing other practical advantages particularly in cases in which
high pressures are employed and high speeds are obtained.
My invention is applicable to marine engines and also to stationary or other
engines; and the cylinders of any of such engines may be disposed vertically, or
horizontally, or at any desired angle.
In carrying out my invention in the case, for example, of inverted-cylinder
screw-propeller engines, according to one modification, I arrange the four cylinders
in a single row and I connect their piston rods to separate cranks on the shaft.
The crank shaft is made up of two lengths, one length having on it the cranks for
the high-pressure or first-stage and the second-stage cylinders, and the other length
having on it the cranks for the third-stage and fourth-stage cylinders. The two.
cranks for the first-stage and second-stage cylinders are diametrically opposite to
each other, and those for the third-stage and fourth-stage cylinders are diametrically
opposite to each other, but at right angles to the other two cranks. It results from
this arrangement that the engines are in two pairs, each pair comprising two
cylinders the pistons of which, being connected to diametrically opposite cranks,
move oppositely to each other; and each cylinder having paired with it the one
the moving parts connected with which are the nearest in weight to its own moving
parts. The weights of the moving parts thus, to a large extent, counterbalance
each other; and they may be made to do so more or less completely by suitably
increasing the weight of the otherwise lighter part or parts. The crank shaft may
consist of more than two pieces if preferred.
Any suitable known construction and arrangement of distribution valves and
valve gear may be adopted in the improved engines, the diametrically-opposite
disposition of the cranks of two adjacent cylinders admitting of a simple
arrangement of the valves and valve gear, as is well understood. The engines may
also be provided with pipes or passages and stop valves, allowing of their being
worked differently accordingly as it may be desired to make them develope more
or less power at different times. Thus for a maximum power each pair of cylinders
may be worked as a separate ordinary compound engine, high-pressure steam being
supplied to both the first and the third cylinders, and the second and fourth being
connected to the condenser.
Four-stage or quadruple-expansion engines of the improved kind hereinbefore
described may be constructed so as to occupy little if any greater space
longitudinally than triple-expansion engines yielding less power, owing to the
arrangement of the cranks and the diminished space required for their bearings.
Dated this Eighth day of August 1892.
EDMUND HUNT,
Applicant's Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in Compound Steam Engines:
I, ALEXANDER CARNEGIE KIRK, LL.D. of the firm of Robert Napier &
Sons, of Lancefield. House, Glasgow, in the County of Lanark,. North Britain,
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained-in. and by
the following statement, that is to say :-
-
My said invention relates principally to such compound steam engines as are
constructed for ordinarily working with four stages of expansion, and it comprises
improved combinations and arrangements of parts, diminishing vibration and
strains and possessing other practical advantages particularly in cases in which
high pressures are employed and high speeds are obtained.
My invention is applicable to marine engines and also to stationary or other
engines; and the cylinders of any of such engines may be disposed vertically, or
horizontally, or at any desired angle. And my invention comprises the combination
in a compound steam-engine, with a shaft made with four cranks, of four double-
acting cylinders of which the first-stage and second-stage cylinders form a pair
in one framing or combination of castings and the third-stage and fourth-stage
cylinders form a second pair in another framing or combination of castings distinct
from that of the first pair. The pistons of one pair of cylinders being connected
to diametrically opposite cranks and the pistons of the other pair being connected to
diametrically opposite cranks which are at right angles to those of the first pair,
and distribution-valves and casings at the sides of the cylinders, the parts being
constructed and arranged in a manner hereinafter described.
And in order that my said invention and the manner of performing the same
may be properly understood I hereunto append a sheet of explanatory drawings to
be hereinafter referred to, and showing as much of a compound steam-engine,
constructed for working with or two or four stages of expansion, as is necessary to
explain my invention.
Figure, 1, of the drawings is a sectional plan, and Figure, 2, a sectional side
elevation:
In these drawings the same reference letters and numerals are used to mark the
saine or like parts wherever they are repeated.
In carrying out my invention in the case, for example, of inverted-cylinder
screw-propeller steam-engines according to the modification shown in the drawings,
I arrange the four cylinders, A, B, C, D, in a single row, and I connect their piston
rods; E, F, G, and, H, to separate cranks, J, K, L, and, M, on the shaft, N. The
crank shaft, N, is made up of two lengths, one length having on it the cranks, J,
and, K, for the high-pressure or first-stage and the second stage cylinders, A, and, B,
and the other length having on it the cranks, L. and, M, for the third-stage and
four-stage cylinders, C, and, D. The two cranks, J, and, K, for the first-stage and
second-stage cylinders; A, and, B, are diametrically opposite to each other; and the
cranks; L, and M, for the third-stage and fourth-stage cylinders, C, and D, are
diametrically opposite to each other but at right angles to the other two-cranks. It
results from this arrangement that the engines are in two pairs, each pair comprising
two-cylinders the pistons of which being connected to diametrically opposite cranks,
move oppositely to each other; and each cylinder having paired with it the one the
moving parts connected with which are the nearest in weight to its own moving:
parts. The weights of the moving parts thus to a large extent.counterbalance.each
other; and they may be made to do so more or less completely by suitably
increasing the weight.of the otherwise lighter part or parts. The crank shaft, N,
may consist of more than two lengths or pieces, if preferred, and is carried in a
framing or bed-plate, P, constructed in a suitable way. The cylinders, A, B, C,
and, D, are carried on columns, Q, R, and, S, as is usual, the column, Q, being

page_text: made broad enough at its upper part to carry the cylinders, A, and, B, and to
contain the guides, T, and, V, for their respective piston rods, E, and, F.
Any suitable known construction and arrangement of distribution valves and
valve gear may be adopted in the improved engines, the diametrically-opposite
disposition of the cranks of two adjacent cylinders admitting of a simple
arrangement of the valves and valve gear, as is well understood.
The engines are provided with pipes or passages and stop valves to enable them
to be worked differently accordingly as it may be desired to make them develope
more or less power at different times. Thus for a maximum power each pair of
cylinders may be worked as a separate ordinary compound engine, high-pressure
steam being supplied to both the first and the third cylinders, A, and, C, and the
second and fourth cylinders, B, and, D, being connected to the condenser (not
shown). A valve casing, W, is provided being formed with five separate
spaces, W 1, W.2, W 3, W 4, and, W 5, and fitted with four valves, X, X 1,
X2, X 3. A branch, Z1, from the main steam pipe, Z, supplying the valve
casing, A 1, leads high-pressure steam to the space, W 1, of the valve casing, W,
and is thence led, if the valve, X, is open to the space, W 4, and thence when the
valve, X 1. is open through the space, W 2, and pipe, Z 2, to the valve casing, C 1,
of the third cylinder, C. The steam from the second cylinder, B, exhausts by the
pipe Z3, to the space, W 3, of the valve casing, W, and from it passes when the
valve, X3, is open to the space, W 5, and thence to the condenser. The exhaust
steam from the fourth cylinder, D, escapes by the connection, Z 4, to the condenser.
When the four cylinders, A, B, C, and, D, are to be worked as a quadruple-
expansion engine, the valves, X, and, X 3, are closed the valve, X 1, remaining
open and the valve, X 2, being opened. The exhaust steam from the second
cylinder, B, then passes through the spaces, W 3, W 4, W 2, and pipe, Z 2, to the
the valve casing, C1, of the third cylinder, C, the exhaust steam from the fourth
cylinder, D, escaping as before by the connection, Z 4, to the condenser.
Four-stage or quadruple-expansion engines of the improved kind hereinbefore
described are constructed so as to occupy little if any greater space longitudinally
than triple-expansion engines yielding less power, owing to the arrangement of
the cranks, J, K, L, and, M, and the diminished space required for their
bearings, P 1.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what 1
claim is :-
1. In a compound steam engine constructed for working with four stages of
expansion the combination, with a shaft made with four cranks, of four double-
acting cylinders of which the first-stage and second-stage cylinders form a pair in
one framing or combination of castings, and the third-stage and fourth-stage
cylinders form a second pair in another framing or combination of castings distinct
from that of the first pair, pistons of one pair of cylinders connected to
diametrically opposite cranks, and the pistons of the other pair connected to
diametrically opposite cranks which are at right angles to those of the first pair,
and distribution valves and casings at the sides of the cylinders, the parts being
constructed, arranged, connected, and operating substantially as and for the purposes
hereinbefore described.
2. In a compound steam engine, constructed for working with four stages of
expansion providing passages or pipes and stop valves arranged to allow of two
separate supplies of high-pressure steam being worked with two stages of
expansion substantially as and for the purposes herein before described.
Dith an fM 1902
EDMUND HUNT,
Applicant's Agent.