Improvements in and relating to Rotary Exhausters and Applicable as Pumps or Engines.
Year: 1898

page_text: Date of Application, 11th Oct., 1898
Complete Specification Left, 11th July, 1899-Accepted, 7th Oct.,
1899
Improvements in and relating to Rotary Exhausters and Applicable
as Pumps or Engines.
I, JOHN SHARP, of 147, East Milton Street, in the County of the City of
Glasgow, Engineer, do hereby declare the nature of my invention to be as
follows:
This invention has reference to improvements in and relating to rotary gas
exhausters, and applicable as pumps or engines.
A hollow
According to my improvements I have a cylindrical casing and on a central
stationary hollow shaft within said casing 1 mount a series, preferably three
radial arms or blades with hinge eyes at spaced distances apart.
barrel or drum is mounted within the outer casing and where the blades pass
through revolving barrel to circumference of outer casing the barrel is fitted
with long slotted circular tongue pieces to form a universal joint so as to be
automatically adjustable to suit the varying relative angles of blades during each
revolution.
The inner barrel has a central shaft formed or connected to its one end and
is either coupled direct to an engine crank shaft or driven by suitable gearing
so that when the barrel revolves the blades mounted on inner hollow centre are
carried round with it.
In order that the interior of barrel may be utilized for pumping in addition
to the outer casing, the outside diameter of hinged eyes of blades may be made
to touch the inside circumference of barrel so as to prevent the passage of
gas at that point, the centres of barrel and of eyes being eccentric to each other.
With this arrangement it is necessary that the inside surface of the revolving
barrel be bored out, and that the outer surface of the hinged eyes be machined
to a true circle, for the same reason as the outside surface of barrel is turned and
the inner surface of outer casing is bored.
By further modifications the inner and outer surfaces of revolving barrel
and the outer surface of eye need not be machined as described as by the follow-
ing constructions of ports and fittings it is unnecessary to stop the passage of
This is obtained by forming
gas by contact of the machined surfaces referred to.
the inlet and outlet ports of the inner chamber so that by the passage of one
blade the opening of inlet port to upper portion of inner barrel is coincident
with the shutting off of the outlet port to the same space by the blade opposite
so that even when there is an open space between the outer eye and the inner
surface of the drum, the passage of the gas from the outlet to the inlet side is
prevented by means of the blades alone. The blades exposed in the outer
chamber and inlet and outlet ports thereon are also arranged so that the passage
of gas at the bottom between outer surface of revolving barrel and inner surface
of outer casing is entirely prevented by the blades opening and shutting in the

page_text: manner described for the inner chamber; and any gas which might pass through
the space at the bottom left between the outer surface of barrel and inner surface
of casing would be stopped by the blades alone one of which is always in action.
By this means the usual leakage which takes place between the two points of
contact, that is, between the inner surface of revolving barrel and the outer
surface of eye,
and the outer surface of revolving barrel with the inner surface
of outer casing is now prevented as described in a more efficient manner which
permits of adjustable packing pieces especially required for high pressures. It
will further be seen that the turning of the outer and inner circular surfaces
of revolving barrel exposed to the working chambers for the purpose described
as is usual will now be quite unnecessary, it being only necessary to machine the
ends for running in circular grooves.
By a further modification the revolving barrel may be made open right through
and be kept in position by working in circular grooves formed in the end covers,
and in contra distinction to the mode of driving described, in which the barrel
is driven direct and carries with it the working blades, I now purpose to mount
a shaft centrally to the outer case so that it may pass through stuffing boxes in
each end cover, and be supported at each end. On this shaft one of the blades
is fixed securely at the eye by means of keys or feathers, and the other two
blades are mounted loose on same shaft in order that they may be free to take
up the continually changing relative positions of blades. The shaft with its
fixed blade now becomes the main driver and may be coupled to an engine, and
when in motion the fixed blade is carried round with it so as to drive and pro-
duce the circular motion of the revolving barrel, which in turn carries round the
two loose mounted blades.
The gases pass direct through a port into outer casing and discharge through a
similar port on the opposite side to this. In addition to this the gases are also con-
ducted from the inlet side through a port on the end cover into interior of inner
barrel, and are discharged through another port diametrically opposite to this,
or other suitable equivalent, and by this means the inner area of revolving barrel
is filled and discharged three times per revolution in addition to the three
volumes discharged between outer casing and barrel per revolution.
In applying this method to a rotary engine high pressure steam or fluid passes
through a port in end cover, and acts on that portion of blade exposed between
the inner surface of barrel and outer diameter of eye of hinge, so as to cause it
to revolve until the revolving barrel has made one half revolution when it begins
to uncover a suitable port diametrically opposite which allows the steam to
exhaust direct towards another port in end cover in communication with the
outer casing. This steam will then act as in a low pressure cylinder by ex-
pansion, the pressure of which will act on that portion of blade exposed between
the outer surface of revolving barrel and inner surface of outer casing, and the
steam will continue to expand and act on this blade during the succeeding portion
of the revolution of revolving barrel after which it begins to open a fourth port
in the end cover communicating either with a condenser or the atmosphere.
In this way the steam is expanded several times of its original volume as in
multiple expansion engines.
By a suitable arrangement of valves and pipe connections between the ports
mentioned the action desired of the steam can be reversed and therefore con-
stitute a reversible compound rotary engine.
Dated the 10th day of October 1898.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents,

page_text: Improvements in and relating to Rotary Exhausters and Applicable
as Pumps or Engines.
I, JOHN SHARP, of 147, East Milton Street, in the County of the City of
Glasgow, Engineer, do hereby declare the nature of my invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being made to the accompanying
sheets of illustrative drawings:-
This invention has reference to improvements in and relating to rotary gas
exhausters, and applicable as pumps, blowers or engines.
And in order that my said invention and the manner of carrying same into
practice may be properly understood, I have hereunto appended three sheets of
explanatory drawings, in which the same reference letters are used to indicate
corresponding parts in all the figures where shown. Figure 1 is a longitudinal
vertical section, Figure 2 a section taken on the line 2-2 of Figure 1, Figure 3
a section taken on the line 3-3 of Figure 1, and Figure 4, an end elevation of
end cover, all illustrative of one arrangement of exhauster, pumps or blower as
constructed according to my improvements, the blades in this modification being
mounted loose on a central spindle and made to revolve round said centre by
means of an eccentrically arranged revolving barrel.
Figure 5 is a longitudinal vertical section. Figure 6 a section taken on the
line 6-6 of Figure 5, and Figure 7 an end elevation of each end cover, all illus-
trative of another arrangement of my improvements in which there is a central
driving shaft with one blade keyed to same, the other blades running loose on
same centre, to accomodate the changing relative position of blades. Figure 8
is a longitudinal vertical section, Figure 9 a section taken on the line 9-9 of
Figure 8, and Figure 10 an end view of cover and reversing valve, all illus-
trative of my improvements as applied in the form of a rotary engine.
Referring to Figures 1 to 4 of these drawings:-
A hollow
According to my improvements I have a cylindrical casing. A and on a central
stationary hollow shaft B within said casing I mount a series, preferably three
radial arms or blades b with hinge eyes b¹at spaced distances apart.
barrel or drum B₁ is mounted eccentrically within the outer casing; and where
the blades pass through revolving barrel B₁ to circumference of outer casing A
the barrel is fitted with long slotted circular tongue pieces 12 to form a universal
joint so as to be automatically adjustable to suit the varying relative angles of
blades 6 during each revolution.
The inner barrel B' has a central shaft C formed or connected to its one end,
and is either coupled direct to an engine crank shaft or driven by suitable gearing
so that when the barrel B' revolves the blades b mounted on inner hollow
centre B are carried round with it.
In order that the interior B2 of revolving barrel B₁ may be utilized for pumping
in addition to the outer casing A', the outside diameter of hinged eyes 6 of
blades 6 is made to touch the inside circumference of barrel at 63 so as to prevent
the passage of gas at that point, the centres of barrel B' and of eyes 61 being
eccentric to each other. With this arrangement it is necessary that the inside
surface of the revolving barrel B₁ be bored out, and that the outer surface of
the hinged eyes be machined to a true circle, for the same reason as the
outside surface of barrel is turned and the inner surface of outer casing is bored,
so as to maintain a line of contact at b*.
By further modifications the inner and outer surfaces of revolving barrel need
not be machined as described as by the following constructions of ports and

page_text: fittings it is unnecessary to stop the passage of gas by contact of the machined
surfaces referred to.
This is obtained by forming the inlet and outlet ports P, P and P1, P1, respec-
tively of the inner and outer chambers 132 and A¹ so that by the passage of the
blade 6 when revolving in the direction indicated by the arrow in Figure 2, the
opening of inlet port P to upper portion of inner barrel B' is coincident with
the shutting off of the outlet port 1" to the same space by the blade opposite,
so that even when there is an open space between the outer eye and the inner
surface of the drum B¹ the passage of the gas from the outlet to the inlet side
is prevented by means of the blades alone and not as previously described by
contact at 63. The blades exposed in the outer chamber A¹ and inlet and outlet
ports Pthereon are also arranged so that the passage of gas at the bottom
between outer surface of revolving barrel B' and inner surface of outer casing A
is entirely prevented by the blades opening and shutting in the manner
described for the inner chamber B2 so as not to depend on contact at 6 as pre-
viously described, and any gas which might pass through the space 6+ at the
bottom left between the outer surface of barrel B¹ and inner surface of casing A
would be stopped by the blades balone one of which is always in action and
intercepts the réturn flow. By this means the leakage which would take place
between the two points of contact that is, at 3 between the inner surface of
revolving barrel B₁ and the outer surface of eye b¹ and at 64 between the outer
surface of revolving barrel B' and the inner surface of outer casting A is now
prevented as described in a more efficient manner which permits of adjustable
packing pieces 65 especially required for high pressures. It will further be seen
that the turning of the outer and inner surfaces of revolving barrel B¹ exposed
to the working chambers for the purpose described as is usual will now be quite
unnecessary, it being only necessary to machine the ends for running in circular
grooves in both end covers.
By a further modification as shown in Figure the revolving barrel B¹ may
be made open right through and be kept in position by working in circular
grooves formed in the end covers D, and in contra distinction to the mode
of driving described, in which the barrel B¹ is driven direct and carries with it
the working blades b, I now propose to mount a shaft B centrically to the outer
case A so that it may pass through the stuffing box $ in end cover D, and be
supported at the other extreme end. On this shaft B one of the blades is fixed
securely at the eye b¹ by means of keys or feathers E, and the other two blades
are mounted loose on same shaft B in order that they may be free to take up
the continually changing relative positions of blades. The shaft B with its
fixed blade b now becomes the main driver and when in motion the fixed blade
is carried round with it so as to drive and produce the circular motion of the
revolving barrel B₁ which latter carries round the loose mounted blades.
The gases pass direct through a port P into outer casing A¹ and discharge
through a similar port PI on the opposite side to this. In addition to this the
gases are also conducted from the inlet side through a port P on the end cover D
into interior B2 of inner barrel B¹, and are discharged through another port P¹
diametrically opposite to this, or other suitable equivalent, and by this means
the inner area B2 of revolving barrel B1 is filled and discharged three times per
revolution in addition to the three volumes discharged in chamber A¹ between
outer casing A and barrel B₁ per revolution; and both sets of inlet and outlet
ports P, P, may be arranged in one end cover D or one inlet and outlet port may
be formed on each end cover D.
In applying this method to a rotary engine as shown in Figures 8 to 10 high
pressure steam or fluid passes through port P in end cover, and acts on that
portion of blade 6 exposed between the inner surface of barrel B¹ and outer
diameter of eye b¹ of hinge, so as to cause the barrel B₁ to revolve. This high
pressure action will continue on said blade b until it begins to uncover the
port P¹ to inner chamber B² which allows the high pressure steam to exhaust

page_text: direct towards to another port P in end cover D in communication with the
outer casing A. This steam will then act as in a low pressure cylinder by
expansion, the pressure of which will act on that portion of blade 6 exposed
between the outer surface of revolving barrel B₁ and inner surface of outer
casing A, and the steam will continue to expand and act on this blade during
the succeeding portion of the revolution of revolving barrel B¹, after which it
begins to open a fourth port P¹ in the end cover D communicating either with
a condenser or the atmosphere. In this way the steam is expanded several times
of its original volume as in multiple expansion engines.
By means of a disc valve V in combination with five ports including the steam
inlet and exhaust ports s, and e, together with the ports P communicating with
the inner and outer chambers B2, A¹, the flow of fluid can be directed so as to
enter the passages and ports P, P₁, in the proper order to produce motion for
reversing the direction of revolution of shaft B.
It will be seen by the arrangement of one fixed blade 6 to driving shaft B
as shown in Figures 5 to 8, the inner barrel B¹ is open throughout its length,
thus being always in equilibrium endways, and therefore not influenced in this
direction by the degree of pressure as in the foregoing examples in which the
barrel B¹, received or transmitted its power by means of its shaft C. Thus it
will be seen that by the latter arrangement it is necessary for the revolving
barrel B¹, to have one end closed as shown in Figure 1, and which is exposed to
the pressure of fluid in inner chamber B³, the effect of which is to push it hard
against the corresponding end cover D, and so setting up a great amount of
frictional resistance which will act as a brake, the amount of which resistance
will depend on the working pressure in inner chamber, and cause a corresponding
loss of efficiency.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
First. The arrangement in combination of the parts of a rotary exhauster,
pump, or blower, with the blades mounted loose on central spindle and made
to revolve round said centre by an eccentrically arranged revolving barrel and
inlet and outlet ported connections to inner and outer chambers, substantially
as herein described in reference to Figures 1 to 4 of the accompanying drawings.
Second. The arrangement in combination of the parts of a rotary exhauster,
pump, or blower having a central driving shaft and one blade keyed to same,
the other blades running loose on same centre, substantially as herein described
in reference to Figures 5 to 7 of the accompanying drawings.
Third. The arrangement in combination of the parts of a rotary engine with
blades, barrel, and ported connections, substantially as herein described in
reference to Figures 8 to 10 of the accompanying drawings.
Fourth. In rotary exhausters, pumps, or engines, the formation and arrange-
ment of inlet and outlet ports in end cover and side branches in relation to blades
so that these inlet and outlet ports are isolated from each other by means of the
blades only, and thereby dispensing with lines of contact at the points 63, 4,
and obviating the necessity of turning and boring of the inner and outer circular
surfaces of revolving barrel substantially as herein described in reference to the
accompanying drawings.
Fifth. In rotary exhausters, pumps, or engines, the arrangement of two or
more revolving blades mounted on central spindle in combination with inlet and
outlet ports P, P¹, by means of which, the volume of fluid represented by the
area B, of inner chamber embraced between the radial line of ports P, P¹, is
swept out the same number of times per revolution as the number of blades
adopted, substantially as herein described in reference to the accompanying
drawings.
Sixth. In rotary exhausters, pumps, or engines, the arrangement of through

page_text: shaft with fixed blade so as to make the inner barrel open throughout its length;
and therefore always in equilibrium endways, substantially as herein described
in reference to Figures 5 to 9 of the accompanying drawings.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.