Improvements in Reciprocating High-speed Fluid Pressure Engines.
Year: 1899

page_text: Date of Application, 4th Mar., 1899
Complete Specification Left, 27th Dec., 1899-Accepted, 10th Feb., 1900
PROVISIONAL SPECIFICATION.
Improvements in Reciprocating High-speed Fluid Pressure Engines.
We, SAMUEL CLELAND DAVIDSON, of Sirocco Engineering Works, Belfast,
Ireland, Merchant, and ALEXANDER BASIL WILSON, of Holywood, County Down,
Ireland, Engineer do hereby declare the nature of this invention to bu as
follows:-
Our invention has reference to reciprocating high-speed engines, in which the
motive Huid employed is steam, compressed air, or gases (hereinafter referred
to as the motive fluid), and our improvements refer more particularly to the type
thereof in which the motive fluid operates on one side only of the piston or
pistons, and is admitted to or exhausted from the piston cylinder or cylinders
by means of a rotary valve on which the engine governor is directly mounted,
and rotated thereby, within the steam chest. The engine may be constructed
on the single or a tandem arrangement of cylinders and pistons on one side of
said rotating valve; or a single or a tandem arrangement of cylinders and pistons
may be arranged on both sides of the rotating valve and in this case the said
rotating valve admits and exhausts the motive fluid to or from the cylinder or
cylinders on the respective sides thereof alternately, the pistons on the respective
sides being connected to oppositely acting cranks on the crank shaft; this
arrangement of the engine we term a double engine. In addition to the pistons
on which the steam acts, buffer or cushion cylinders and pistons are also employed,
in which cylinders air is compressed on the return or exhaust stroke of the
steam pistons to maintain a continuous thrust pressure on the connecting rod,
and on the crank and cross-head pins throughout the entire revolution of the
crank shaft.
In engines of the type above referred to, and as hitherto constructed, the
pistons of each series have been connected by a rod passing through a stuffing
box and gland in the metal partition separating the pistons, which are thus in
tandem operation with one another, and the rotating valve spindle when it is
driven off the crank shaft, enters the valve sleeve or chamber through a stuffing-
box or gland in the metal partition between same and the chamber or compart-
ment enclosing the crank shaft, and in the case of compound engines, between
one steam passage and another in the valve sleeve.
The employment of such glands and stuffing boxes for the purpose of prevent-
ing the escape of the motive fluid from one cylinder or valve passage to another,
or to the crank shaft chamber, involves more or less friction, according to the
tightness of the packing in the stuffing-boxes and this friction has to be overcome
at the expense of the efficiency of the engine. The packing also, through wear,
becomes slack and consequently requires to be tightened up from time to time,
and not infrequently produces grooving in the piston rods and spindles working
therein. In engines of the above described type it is a matter involving very
considerable extra cost of construction, to provide suitable means for con-
veniently getting at such stuffing-boxes in order to adjust them without having
lo take the parts of the engine asunder.

page_text: One object of our invention is to construct an engine of the type or class above
referred to, so that the employment of said stuffing-boxes in the metal divisions
or partitions dividing one cylinder or one valve passage from another, or through
which the valve spindle enters the valve sleeve or chamber, is entirely obviated.
With this object we form or construct upon one or both faces of the metal
partition or plate dividing one cylinder from another, in their tandem arrange-
inent, or in the partition through which the rotary valve spindle enters the valve
sleeve or chamber, projections or bosses, the total length of which is approxi-
mately not less than two and a half times, but preferably (when construction will
admit of it) three or four times the diameter of the rod which passes through
same, said projections being accurately bored to so fit the rod or spindle, as to
form a sleeve in which the rod or spindle may move without unnecessary fric-
tion; and on the upper lip or end of said sleeve, we form a cup or hollow around
same, for the collection of any moisture or lubricant from the steam or air
surrounding same. By this means, the rod is kept lubricated, and being an
accurate working fit in said sleeve, the width of passage way for leakage between
the rod and the sleeve is so small, as compared with its length, that practically
no leakage of the motive fluid takes place, as we have ascertained from numerous
experiments that the time limit in regard to the duration of the pressure, operates
as a most highly important factor in the matter. This in high speed engines,
running at anything over 200 revolutions per minute, means that whatever leak-
age can occur, must take place during a portion only of a revolution, approxi-
mately one-half, and therefore during a minimum time of say 1/400th part of a
minute, or 1/7th of a second, which is followed by a relief of the pressure for
an equivalent period, thus causing an intermittent pressure of exceedingly short
duration and which might almost be described as percussional and we have
ascertained in our investigations that the frictional resistance which steam or
air acting with such intermittency, encounters to its passage between the sleeve
and contained rod or spindle is so great that practically no leakage of the motive
fluid takes place at the opposite end from where the pressure is operating, during
the period of time that said pressure is in force between each relief thereof; and
as in said construction of engine the piston rods pass through said sleeve with
parallel motion, free from side strain in any direction, and as the valve spindle
rotates in said sleeve similarly free from side strain, no wear takes place, either
in the sleeves or piston rods or spindles, consequently the original fit of the rods
and spindles in the sleeves, remains substantially unaltered through a long period
of time, and engines constructed as herein before described are more durable and
satisfactory in operation, and simpler and cheaper in regard to construction. In
order to further counteract any tendency to leakage, we may form one or more
circumferential grooves in the sleeve so as to act as a sort of trap to the motive
fluid.
Improvements in Reciprocating High-speed Fluid Pressure Engines.
We, SAMUEL CLELAND DAVIDSON, of Sirocco Engineering Works, Belfast,
Ireland, Merchant, and ALEXANDER BASIL WILSON, of Holywood, County Down,
Ireland, Engineer, do hereby declare the nature of this invention and in what

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:.
-
Our invention has reference to reciprocating high-speed engines, in which the
motive fluid employed may be steam, compressed air, or gases (hereinafter referred
to as the motive fluid), and our improvements refer more particularly to the type
thereof in which the motive fluid operates on one side only of the piston or
pistons, and is admitted to or exhausted from the piston cylinder or cylinders
by means of a rotary valve on which the engine governor is directly mounted,
and rotated thereby, within the steam chest. The engine may be constructed
on the single or a tandem arrangement of cylinders and pistons on one side of
said rotating valve; or a tandem arrangement of cylinders and pistons
may be arranged on both sides of the rotating valve and in this case the said
rotating valve admits and exhausts the motive fluid to or from the cylinder or
cylinders on the respective sides thereof alternately, the pistons on the respective
sides being connected to oppositely acting cranks on the crank shaft; this
arrangement of the engine we term a double engine. In addition to the pistons
on which the steam acts, buffer or cushion cylinders and pistons are also employed,
in which cylinders air is compressed on the return or exhaust stroke of the
steam pistons.
In engines of the type above referred to, and as hitherto constructed, the
pistons of each series have been connected by a rod passing through a stuffing
box and gland in the metal partition separating the pistons, which are in
tandem relation with one another, and the rotating valve spindle when it is
driven off the crank shaft, enters the valve sleeve or chamber through a stuffing-
box or gland in the metal partition between same and the chamber or compart-
ment enclosing the crank shaft, and in the case of compound engines, between
one steam passage and another in the valve sleeve.
The employment of such glands and stuffing boxes for the purpose of prevent-
ing the escape of the motive fluid from one cylinder or valve passage to another,
or to the crank shaft chamber, involves more or less friction according to the
tightness of the packing in the stuffing-boxes and this friction has to be overcome
at the expense of the efficiency of the engine. The packing also, through wear,
becomes slack and consequently requires to be tightened up from time to time,
and not infrequently produces grooving in the piston rods and spindles working
therein. In engines of the above described type it is a matter involving very
considerable extra cost of construction to provide suitable means for con-
veniently getting at such stuffing boxes in order to adjust them without having
to take the parts of the engine asunder.
One object of our invention is to construct an engine of the type or class above
referred to so that the employment of said stuffing-boxes in the metal divisions
or partitions dividing one cylinder or one valve passage from another, or through
which the valve spindle enters the valve sleeve or chamber, is obviated.
With this object we form or construct upon one or both faces of the metal
partition or plate dividing one cylinder from another, in their tandem arrange-
ment, or in the partition through which the rotary valve spindle enters the valve
sleeve or chamber, projections or bosses accurately bored to so fit the rod or spindle,
as to form a sleeve in which the rod or spindle may move without unnecessary
friction; and on the upper lip or end of said sleeve, we form a cup or hollow around
same, for the collection of any moisture or lubricant from the steam or air
surrounding same. By this means the rod is kopt lubricated, and being an
accurate working fit in said sleeve, the width of passage way for leakage between
the rod and the sleeve is exceedingly small, as compared with its length and
the moisture or admixture of moisture and lubricant which collects in the groove
or cup around the upper end of the sleeve is, by the action of capillary attraction
held so effectively between the rod or spindle and this sleeve as to practically

page_text: form a fluid packing therein so that no leakage of the motive fluid takes place,
and in special respect to the piston rods as described the alterations of pressure
in the fluid on either side of said sleeve are of such rapidity in fast running
engines that the fluid which mainly consists of oil and condensed steam cannot
get into motion entirely in one direction before the reversal of the pressure to
the opposite direction stops it, and it is therefore effectively retained in the sleeve.
The time limit in regard to the duration of the pressure operating alternately on
each side of the sleeve is thus an important factor in producing this result.
This in high-speed engines running at anything over 200 revolutions per minute
means that whatever dislodgment of fluid from between the rod or spindle and
sleeve or whatever leakage of steam or air through same that can occur, must
take place during a portion only of a revolution, approximately one-half and
therefore during a maximum time of say 1/400 part of a minute; pressure is
followed by relief of pressure for an equivalent period, this causing an inter-
mittent pressure of exceedingly short duration, and which might almost be
described as percussional. In this construction of engine the piston rods pass
through said sleeve with parallel motion and consequently free from side strain,
and as the valve spindle rotates in said sleeve similarly free from side strain, no
practical wear takes place, either in the sleeves or piston rods or spindles, conse-
quently the original fit of the rods and spindles in the sleeves remains substan-2
tially unaltered through a long period and engines constructed as hereinbefore
described are more durable and satisfactory in operation, and simpler and cheaper
in regard to construction, than other high speed engines as ordinarily made.
In the accompanying drawings:-
―:
Figure 1 is an outside elevation of a double engine in which our invention
is embodied.
Figure 2 is a section on line CD of Figure 1.
Figure 3 is a sectional elevation of this double engine.
Figure 4 is a section on line EF of Figure 3.
Figure 5 is a section on line GH of Figure 3.
Figure 6 is a section on line IK of Figure 3.
Figure 7 is a sectional elevation of a tandem compound double engine in which
our invention is embodied.
Figure 8 is a section on line L M of Figure 7.
Figure 9 is a section on line NO of Figure 7:
Figure 10 is a section on line PQ of Figure 7.
Referring first to Figures 1 to 6.-
aa are the steam cylinders to which steam is admitted and from which it is
exhausted by means of the rotary valve b. The valve b revolves in a liner
sleeve the governor c being directly mounted on the rotary valve b and rotated
thereby within the steam chest d. The valve b is actuated by the valve spindle e
which enters the valve chamber f from the crank chamber, through the sleeve g
formed on the boss or projection constructed on the metal partition h, separating
the valve chamber f from the crank chamber j. The sleeve g is recessed at k
to form a cup or hollow round the valve spindle e for the collection of moisture
and lubricant. In the steam cylinders a the steam acts upon the upper face of
the steam piston 7, which is connected to the air buffer piston m, working in the
air cushion chamber n, by the piston rod o which moves to and fro through the
sleeve 2, formed by bosses or projections constructed on the metal division plate
or partition q, separating the steam cylinder a from the air cushion chamber n.
The sleeve is recessed at r to form a cup or hollow round the piston rod o for
the collection of moisture and lubricant.
In the tandem compound arrangement, as shown in Figures 7 to 10 the steam
pistons working in the high pressure steam cylinder t is connected to the steam
piston, working in the steam cylinder a by the piston rod u which moves to a
and fro through the sleeve v formed by bosses or projections constructed on the
metal division plate or partition w, separating the steam cylinder t from the

page_text: steam cylinder a. The sleeve vis recessed at r to form a cup or hollow round
the piston rod u, for the collection of moisture and lubricant.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. In reciprocating high-speed fluid pressure engines a sleeve through which
the piston rod moves to and fro at the end of the engine cylinder with a good work-
ing fit, said sleeve having at its upper end a cup around said rod to collect and feed
moisture between said sleeve and said rod whereby under intermittent pressures
leakage of the motive fluid between said rod and said sleeve is prevented without
the use of a packing gland, substantially as set forth.
2. In reciprocating high-speed fluid pressure engines in which the motive fluid
is admitted to or exhausted from the cylinder or cylinders by means of a rotary
valve, a sleeve in which the valve spindle rotates at one end of the valve
chamber with a good working fit. said sleeve having at its upper end a cup
around said spindle to collect and feed moisture between said sleeve and said
spindle whereby under intermittent pressures leakage of the motive fluid between
said sleeve and said spindle is prevented without the use of a packing gland,
substantially as set forth.
3. In a reciprocating high-speed fluid pressure engine the combination of two
cylinders and a continuously rotating valve between said cylinders admitting and
exhausting steam to and from said cylinders alternately in its rotation and
making one rotation for each revolution of the crank shaft, substantially as set
forth.
4. The general arrangement and construction of the single acting double engine
having a continuously rotating valve for admitting and exhausting steam to and
from the engine cylinders alternately, substantially as described with reference
to Figures 1 to 6.
5. The general arrangement and construction of the tandem compound engine,
substantially as described with reference to Figures 7 to 10.
T
T
028
2000
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Chartered Patent Agents.