IMPROVEMENTS IN HIGH-SPEED MOTons
Year: 1884

page_text: COMPLETE
SPECIFICATION.
LANDREW BETTS BROWN, of Rosebank Iron Works, Edinburgh, in the County
of Mid Lothian, North Britain, Engineer, do hereby declare the nature of my said
Invention for "IMPROVEMENTS IN HIGH-SPEED MOTons" and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
My said Invention has for its object to construct improved motors suitable for
being driven by steam or other fluid at a high speed in an economical manner and
without liability to derangement.
My improved motor comprises any convenient number of single-acting cylinders
fixed in radial positions on a disk or frame which is centrally fixed to and rotates
with the shaft driven by the motor. I prefer to construct the motor with four
cylinders placed equidistantly on the disk, the pistons of these cylinders having
jointed to them connecting rods the inner ends of which are jointed on an
eccentrically placed pin which is stationary but which prefer to be on a crank
formed on a short shaft held in the framing of the machine in the same line as the
driven shaft. This shaft of the stationary eccentric pin is by preference held by
pinching friction and will yield and avoid breakage in the event of any excessive
strain acting on it. An important feature of my improved motor consists in
having the pistons and their connecting rods so proportioned as regards area and
weight relatively to the pressure of steam or other fluid employed and to the speed,
as that the pressure of the connecting-rod bearings on the stationary eccentric pin
due to the centrifugal force shall not at any part of a revolution be quite balanced,
when the motor is going at its proper speed, by the pressure of the steam or other
fluid, which acts on the outer sides of the pistons. With this arrangement the
pressure of each connecting rod bearing on the stationary eccentric will always,
when the motor is going at its proper speed, be in the direction towards the
respective piston, so that even if the bearings are slack there can be no knocking or
alternate separations and concussions of the surfaces. It is also an advantageous
feature of my improved arrangements that the lubrication of the working parts
can be effected efficiently and without waste. The pin on which the connecting
rods are jointed is the principal part requiring lubrication but being stationary it
does not tend to throw off the lubricant like an ordinary rotating crank pin, whilst
the lubricant can be conveyed to it in a convenient manner.
A steam motor as made with my improvements is shown on a sheet of
explanatory Drawings hereunto appended, Figures 1 and 2, being respectively,
longitudinal and transverse vertical sections.

page_text: The working parts of my improved motor are placed within a casing, 3, and the
steam from the cylinders exhausts into this casing and passes off from it by an
outlet, 4, leading to the atmosphere or to a condenser. The cylinders, 5, of which
there are four in this example, are cast in one piece with a disk, 6, and are bolted
at one side near their inner ends to a smaller disk, 7, which is fitted with a sleeve
and bearings to rotate on a short stationary shaft, 8, clamped in bearings, 9, formed
on the casing, 3. Each cylinder, 5, has formed at one side of it a valve casing, 10,
fitted with a piston valve, 11; and passages, 12, leading the steam to the
casings, 10, are formed in a cruciform casting, 13, which at its outer ends is bolted
to the cylinders or their valve casings, 10, and at its centre is fixed on a tubular
part, 14, formed at the inner end of the shaft, 15, which is driven by the motor.
The steam finds its way into the tubular part, 14, of the shaft and thence by the
passages, 12, to the valves, 11, through holes, 16, in the shaft communicating with
an annular space in a stationary box, 17, to which the steam supply pipe, 18, is
connected. The box, 17, fits between the boss of the cruciform piece, 13, and a
flange, 19, formed on the shaft, 15, and is made tight by metallic packing
consisting of rings, placed in annular grooves in the end faces of the box, 17. The
shaft, 15, passes through a stuffing box, 20, in the casing, 3, and through a
bearing, 21, in a bracket bolted to the casing.
The stationary shaft, 8, is formed with a crank, 22, and an eccentric pin, 23, this
pin being stationary (unless subjected to an abnormal strain sufficient to make the
shaft, 8, turn in its gripping bearing, 9). The piston, 24, of each cylinder, 5, has
jointed to it by means of a pin which is made tubular for lightness, a connecting
rod, 25, the inner end of which is jointed on the stationary eccentric pin, 23. One
of the four connecting rods, 25, has a single bearing at the middle of the pin, 23,
but each of the others is made with two bearings placed, in the case of cach
connecting rod, at equal distances on opposite sides of the middle of the pin so as
to act jointly like one bearing at the middle, as will be understood from figure, 1.
If the disk, 6, of the cylinders, 5, is turned round, the stationary pin, 23, in
consequence of its eccentric position causes the pistons, 5, to reciprocate in their
cylinders; and if steam is made to act in the cylinders so as to make the pistons
reciprocate the reverse effect takes place and the cylinders, 5, with their disk, 6,
are caused to rotate and the rotation is imparted to the shaft, 15. The cylinders, 5,
rotate about one axis, namely that of the shaft, 15, and the pistons, 24, rotate about
another axis namely that of the stationary eccentric pin, 23, so that there is
practically no reciprocation but only rotations of weights in consequence of which
the motor can be driven at a high speed without the concussive action which is
caused by reciprocation in ordinary engines. At the same time concussive action
might be caused by intermittent action of the steam on the several pistons but
is prevented, as hereinbefore indicated by suitably proportioning the parts
in relation to the pressure of steam and to the speed at which the motor is
intended to work. Thus when the motor is going at its proper speed the
centrifugal force acting on each piston, 5, and its connecting rod, 25, is somewhat
more than the aggregate effective pressure of the steam acting in the opposite
direction on the piston; and as the centrifugal force is almost unopposed whilst
the steam is exhausting it follows that there is always a force tending to move
cach connecting-rod bearing towards the respective cylinder; and there can,
consequently, be no concussion or knocking of the bearing even if it is slack. The
valves, 11, are piston valves and are arranged to act like the pistons, 24, as far as
regards the prevention of concussion or knocking. The steam acts on the outsides
of the valves, but when the motor is going at its proper speed the centrifugal force
of each valve, 11, and its connecting rod, 26, is not completely counterbalanced by
the opposing steam pressure. The connecting rods, 26, of the valves, 11, are
jointed on a stationary eccentric pin, 27, which is fixed by means of an arm or
crank, 28, on the main stationary eccentric pin, 23. The piston valves, 11, admit
steam to the cylinder ports when moving inwards, and when the valves move
outwards the steam exhausts at their inner sides and escapes into the casing, 3.

page_text: Provision is also made for partly exhausting the steam from the cylinders by ports
or holes, 29, in the sides of the cylinders these holes being placed so as to be
uncovered to the interiors of the cylinders when the pistons, 24, are at the inner
ends of their strokes. A large portion of the steam exhausts by these holes, 29,
leaving so much less to be expelled through the valve ports.
The lubricating arrangements are indicated by peculiarly-dotted lines in
Figure, 1, these representing feeders which are partly tubes and partly passages
formed through the parts where they are shown, and leading from an external oil
cup, 30.
One feeder, 31, leads lubricant to the bearing of the sleeve of the small
disk, 7, on the stationary shaft, 8. A second feeder, 32, leads lubricant to the
bearing of the stationary eccentric pin, 23, and branch passages from this bearing
which are formed through the connecting rods, 25, serve to feed the joints
connecting these rods to the pistons, 24. A third feeder, 33, leads lubricant to the
stationary eccentric pin, 27, on which the valve movements depend, branch
passages through the connecting rods, 26, leading lubricant to the joints at the
valves, 11.
My improved motor may be adapted for working as a compound engine by
combining cylinders of unequal sizes and arranging the steam passages and valves
in a suitable manner. And when the motor is used (for driving dynamo-electric
machines for example) in situations where (as in steamers, for example) there are
large compound engines, the motor may be worked either with the high-pressure
steam and have its exhaust passage leading into the intermediate casing of the
large engines; or it may be worked by steam from such intermediate casing and
have its exhaust passage leading into the condenser of the large engines.
My improved arrangements or means for preventing concussion or knocking at
the bearings of the piston connecting rods are applicable to various kinds of motors
having cylinders carried on a rotating disk or frame.
Having thus particularly described the nature of my said Invention and in what
manner the same is to be performed I proceed to ascertain the distinctive features
of novelty thereof by declaring that what I claim is :—
1. The combination of parts forming an improved high-speed motor and
hereinbefore described.
2. The arrangement of two or more single-acting cylinders upon a rotating
frame or disk with pistons which have the motive pressure on their outer sides
and which are jointed upon a stationary eccentric pin substantially as hereinbefore
described.
3. The system of proportioning the pistons and their connecting rods in relation
to the motive pressure and to the intended speed substantially in the manner and
for the purposes herein before describe !.
4. The arranging of the cylinders and other moving parts within a casing into
which the steam or motive fluid exhausts as herein before described.
5. The arrangements for lubricating the various bearings and joints substantially
as herein before described.
6. The system of working the small motor in combination with large compound
engines, either by the high-pressure steam exhausting from the small motor into
the intermediate casing or by steam from the intermediate casing as herein before
described.
Dated this Fourteenth day of March 1884.
EDMUND HUNT,
Applicant's Agent.