An Improved Rotary Engine.
Year: 1899

page_text: An Improved Rotary Engine.
I, JAMES BAIRD, of Devonport, near the City of Auckland, in the Provincial
District of Auckland and Colony of New Zealand, 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:-
This improved rotary engine is constructed to do away with reciprocating motion,
to economise steam, to be almost noiseless in its action, to reduce friction nearly to
a minimum, to have almost steam perfect or other power tightness, and to reduce
and economise engine room space.
This is accomplished by having a double cylinder or two cylinders secured together,
divided by a central piece, with shaft through same, two discs carrying two slide
blocks and four radial piston arms each, one set being at right angles to the other,
the slide blocks adjusted to radial piston arms, hubs connected to central dividing
piece and to cylinder covers with shaft working through same out of centre.
The accompanying drawings indicate eleven figures of which,
Figure 1 is a cross section through ports of cylinder showing end view of disc and
working parts.
Figure 2 is a longitudinal section through a, b, of Figure 1.
Figure 3 is an inside view of cylinder cover.
Figure 4 is an end view of disc.
Figure 5 is a section of disc through c, d, of Figure 4.
Figure 6 is a plan of outer radial piston arm.
Figure 7 is a longitudinal section of outer radial piston arms.
Figure 8 is a longitudinal view of inner radial piston arms.
Figure 9 is a plan of inner radial piston arm.
Figure 10 is an end view of slide block.
Figure 11 is a longitudinal section of slide block.
The parts shown on the different figures are A cylinder, A¹ ports, B disc, C inner
radial piston arms, C¹ outer radial piston arms, D central hubs on central dividing
piece, D' outer hubs on cylinder covers, De space to contain hub, E shaft, E¹ bore for
shaft, F slide blocks, G upright hubs or bosses of inner radial piston arms, H packing
or steam tight rings, J springs for steam tight rings H, K steam tight pieces forming
pistons, round tenon on upright hub or boss G, L¹ recess for round tenon L and
springs, M packing piece, N slots or recesses for slide blocks F to work in, O clearance

page_text: for eyes U and U¹ to work in, P margin of cylinder cover to fit into bore of cylinder,
R set off to accommodate eyes U of opposite radial piston arms C, R¹ set off to
accommodate eyes U¹ of opposite radial piston arms C¹, S clearance for inner and
outer radial piston arms C and C¹ to work in, T flat tenon on end of upright hub or
boss G, T¹ recess for flat tenon, U eye piece for inner radial piston arm, U¹ eye piece
of outer radial piston arms, W annular space or chamber.
The double cylinder A can be cast in one piece with a central dividing piece or wall
or two equal cylinders A can be secured to one another with a central dividing piece
with flanges same as cylinder cover.
This central dividing piece or wall is bored to admit of a shaft E being passed
through it somewhat out of the centre nearer the top than the bottom of the cylinder,
as shown on Figures 1, 2, and 3, on each side of this centre piece a hub D) is secured
to or cast with it each of which is central to bore of cylinder and corresponds with
hubs D¹ on covers, encircling the hubs D are two flat radial piston arms C on each side
of the central dividing piece, the two on one side being at right angles to the two on
the other. The outer ends of these inner radial piston arms C are shaped into up-
right hubs or bosses G and steam tight pieces K, a disc B smaller in diameter or cir-
cumference than the inner side of the cylinder A is centrally adjusted to the shaft E
having a portion of its upper and under surface immediately around the shaft
somewhat hollowed out which permits the eye pieces U and U₁ of the radial piston
arms C and C¹ to work freely. On the upper side of this dise B two other flat radial
piston arms C¹ are so placed that when the cover is placed over and on to the
cylinder A, the hub D' on its inside fits into the eye pieces U1 of the upper radial
piston arms C¹ and the hub D¹ fits closely around the shaft E, this upper hub D¹ has
relatively the same position to the shaft E and upper radial piston arms C¹ as the
lower hub D has to the lower radial piston arms C and shaft E. These upper radial
piston arms C¹ have their outer ends shaped to fit over tenons L and T on the upright
hubs or bosses G and steam tight pieces K of the lower radial piston arms C, and
over and on to slide blocks F adjusted to the upright hubs or bosses G, packing or
steam tight rings H are let into and around the upper and under surfaces of the
disc B so that when the cover is screwed on, the respective surfaces are thereby kept
steam tight, packing pieces M are let into the ends of the steam tight rings H to
provide for wear, and have springs beneath them and let into the disc B to keep the
slide blocks F tight, or jets of steam can be used for the same purpose. The disc B
is secured to the shaft E by a feather or key. This description is for the fittings on
one side of the central dividing piece inside the cylinder A and the same description
applies to the other side of the central dividing piece except that the radial piston
arms C and C¹, slide blocks F, and slots N are placed at right angles on one side of
the central dividing piece to those on the other side. The shaft E being slightly out
of the centre of bore of cylinder and in the centre of the disc B causes the side of
the disc B to be always close up to but clear of the top and adjacent side of the
cylinder A while the opposite and lower side of the dise B is away from the opposite
side of the cylinder A which leaves a wide annular space or chamber W between the
disc B and cylinder A which space W presents the most piston area to the motive
pressure, hence the power. The upright hubs or bosses G and steam tight pieces K
are always in close contact with the inner side or bore of the cylinder A as shown in
Figure 1.
When the steam or other form of power is let in through one of the ports A¹ it
will actuate the nearest piston and drive it round carrying it round with it until the
steam escapes through the opposite port A¹ which it may do to another rotary engine
and from that to another and so on all being fitted on same shaft until the steain is
fully expanded and meanwhile fresh steam will continue to pour in through the other
port A¹ and keep the disc B continuously revolving.
The advantages of this rotary engine are that it is noiseless in working, there is
very little friction, it is almost perfect for steam tightness, the wear is taken up by
packing rings and strips, the centrifugal force keeps the steam tight pieces of the
radial piston arms tight to the bore of the cylinder, the hubs on central dividing

page_text: piece and on inner side of cylinder cover keep radial piston arms from pressing too
hard on bore of cylinder.
In lieu of steam, water, compressed air, gas, elastic fluid or any other suitable form
of power may be used to actuate the rotary engine which, when suitably actuated,
will work or act as a pump or as a fan for blowing wind. There is no reasonable
limit to the size of the engine or the number of cylinders that may be worked on the
same shaft.
It can be made of iron steel or any suitable metal.
The engine will run either way by reversing the steam from right to left.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is :-
First. In a rotary engine a disc centrally mounted on shaft said shaft passing through
cylinder slightly out of centre that is more to top of said cylinder than to bottom
whereby a wide annular space is formed at bottom said disc having on its inner and
outer surfaces inner and outer radial piston arms with upright hubs or bosses and
steam tight pieces on ends of inner arms fitted to ends of outer arms and having slide
blocks adjusted to upright hubs or bosses said inner and outer arms having eye pieces
placed over shaft and adjusted to one another with an inner hub secured to or cast
with central dividing piece and an outer hub secured to or cast with cylinder cover
fitting closely to shaft and between said eye pieces and shaft for the purposes set
forth as herein described and as illustrated by the accompanying drawings.
Second. In a rotary engine inner and outer radial piston arms, said inner arms
having their outer ends extended into upright hubs or bosses and steam tight pieces
on to which outer ends of outer arms fit and form pistons which engage bore of
cylinder said upright hubs or bosses having slide blocks adjusted to and oscillating on
them said slide blocks carrying said arms level with inner and outer surfaces of said
disc centrally mounted on shaft said shaft passing through cylinder slightly out of
centre that is more to top of said cylinder than to bottom whereby a wide annular
space is formed at bottom said inner and outer arms having eye pieces placed over
sbaft and adjusted to one another with an inner hub secured to or cast with central
dividing piece and an outer hub secured to or cast with cylinder cover fitting closely
to shaft and between said eyepieces and shaft for the purpose set forth as herein
described and as illustrated by the accompanying drawings.
Third. In a rotary engine slide blocks adjusted to upright hubs or bosses and
oscillating on them said upright hubs and steam tight pieces being extensions of inner
radial piston arms on to which outer ends of outer arms fit and form pistons which
engage bore of cylinder said slide blocks carrying said arms level with inner and
outer surfaces, of said disc centrally mounted on shaft said shaft passing through
cylinder slightly out of centre that is more to top of said cylinder than to bottom
whereby a wide annular space is formed at bottom said inner and outer arms having
eye pieces placed over shaft and adjusted to one another with an inner hub secured to
or cast with central dividing piece and an outer hub secured to or cast with cylinder
cover fitting closely to shaft and between said eye pieces and shaft for the purpose set
forth as herein described and as illustrated by the accompanying drawings.
Fourth. In a rotary engine an inner hub secured to or cast with central dividing
piece and an outer hub secured to or cast with cylinder cover fitting closely to shaft
and between eye pieces of inner and outer radial piston arms said inner arms having
their outer ends extended into upright hubs or bosses and steam tight pieces on to
which outer ends of outer arms fit and form pistons which engage bore of cylinder said
upright hubs or bosses having slide blocks adjusted to and oscillating on them said
slide blocks carrying said arms level with inner and outer surfaces of said disc
centrally mounted on shaft said shaft passing through cylinder slightly out of centre
that is more to top of said cylinder than to bottom whereby a wide annular space is
formed at bottom for the purpose set forth as herein described and as illustrated by
the accompanying drawings.

page_text: Fifth. In combination in a rotary engine a cylinder having a central dividing
piece with a hub secured to or cast with same said hub bored to hold and holding
shaft slightly out of centre that is more to top of said cylinder than to bottom said
shaft having a disc so centrally mounted on it and within said cylinder that a wide
annular space is formed at bottom of cylinder which said annular space receives either
water, steam, compressed air, gas, elastic fluid or any other suitable form of power
which may be used to actuate pistons and said disc, said disc having on its inner and
outer surfaces inner and outer radial piston arms with upright hubs or bosses and
steam tight pieces on ends of inner arms fitted to ends of outer arms thereby forming
pistons and having slide blocks adjusted to upright hubs or bosses said inner and
outer arms having eye pieces placed over shaft and adjusted to one another with said
inner hub on central dividing piece and outer hub secured to or cast with cylinder
cover fitting closely to shaft and between said eye pieces and shaft said disc having
packing or steam tight rings kept in place by springs and packing pieces let into
ends of steam tight rings said cylinder cover securely fastened to cylinder and right
and left ports for the purpose set forth as herein described and as illustrated by the
accompanying drawings.