Note: Descriptions are shown in the official language in which they were submitted.
l~91Z()l
This invention relates to a new and improved stirling-
type Rankine cycle rotary engine. In the preferred embodiment
hereinafter described in detail, there are a plurality ~f toroidal
cylinders formed in a serie~ of engine blocks ~ecured end-to-end,
one-half of the torus being formed in each of two adjacent blocks.
For each cylinder there is a piston which i8 attached to the outer
periphery of a disk, the disk being fixed for rotation with the
main shaft of the engine. The pressure of the medium which drives
each piston may be applied for as much as 345 degrees of rotation
of the piston and thus the available force is applied on the end
of the lever for substantially the entire rotation of the piston.
- This is one of the principal advantages of the present invention.
At less than full power, the intake of gaseous medium into the
cylinder behind the piston is cut off at any desired point thereby
controlling the output of the engine. Further, one siæe engine
can be controlled to accommodate a wide variety o~ loads.
A principal feature of the invention is the fact that it
is simple in construction and has relatively few moving parts and
is light in weight~
The thermal efficiency of the engine is very high, and
all of the advantages of the stirling-type Rankine cycle engine
are achieved in the invention hereinafter described. Among these
advantages are, in addition to the thermal efficiency, reduction
in noise and of air pollution 3S compared with internal combustion
engines. The fuel comsumption is relatively low compared with
conventional engines.
Still another feature of the invention is the fact that
the engine and its parts are subject to less deterioration and
wear because the heat is low as compared with internal combustion
engines and the speed of rotation is also low.
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When the engine is attached to an automotive vehicle,
it is not necessary to employ a transmission. The torque of the
invention is the highest at stall.
A major feature of the engine is the fact that all the
pressure in the cylinders can be converted to useful work on the
main shaft, pressure being used down to line pressure at exhaust.
The conventional four-cycle internal combustion engine wastes a
substantial part of its pressure out the exhaust. This waste is
greatly minimized in the present invention.
In order that the invention may be readily understood,
one embodiment thereof will now be described by way of example
with reference to the accompanying drawings in which similar
characters of reference represent corresponding parts in each of
the several views.
In the drawings:
Fig. 1 is a schematic view showing the engine and its
associated parts which make up the system;
Fig. 2 is a top plan;
Fig. 3 is a vertical sectional view taken substantially
along the line 3-3 of Fig. 2;
Fig. 4 is a transverse sectional view taken substantially
along the line 4-4 of Fig 3;
Fig. 5 is an exploded perspected view with some of the
parts being shown in different scale than other parts;
Fig. 6 is an enlarged fragmentary top plan view
showing the main cylinder valves;
Fig. 7 is a fragmentary sectional view taken sub-
stantially along the line 7-7 of Fig. 6 and showing the piston
at a different point in its cycle;
Fig. 8 is a theoretical development of a cam used to
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1~1912(~
control the intake valve of the device;
Fig. 9 is a schematic projection onto a flat plane of
the shape of the cam controlling the intake valve;
Fig. 10 is a schematic cross sectional view through the
cam shaft.
Directing attention first to Fig. 1, the engine 11 i8
shown schematically and only one of its multi-cylinder~ is ~hown.
There i8 a block 12 formed with a semi-toroidal cylinder 13. The
block 12 mates with an adjoining block in which a similar semi-
toroidal cylinder 13 has been formed 80 that when the two are
assembled together there is a toroidal cylinder 13. At the axie
of the torus ie main shaft 14. Turning with the shaft 14 i8 a
disk 16 carrying at its outer rim a piston 17 which, in its cycle -
of revolution travels around the cylinder 13. At one point in the
cycle there is a cylinder main valve 18, hereinafter de~cribed in
~;~ detail, which closes off the cylinder 13 to form two portions, one ~ -~
behind the piston 17 and the other ahead of same. The main valve
18 open~ only when the piston 17 is passing therethrough and closes
- imaediately ~hereafter. on one side of main valve 18 is intake -
manifold 19 controlled by valve 21. when the valve 21 is opened,
a gaseous medium under pressure is admitted to the cylinder 13,
driving the piston 17 forward (i.e. clockwise as viewed in Fig. 1).
on the side of main valve 18 opposite intake manifold 19 is an
exhauet manifold 22 through which the medium in front of the pieton
17 is continuously discharged.
An external burner caeing 27 is provided and within the
caeing 27 is a burner 26 which may employ any available fuel.
_ The fuel is stored in tank 28 and is directed to the burner 26 by
pump 29. within the ca~ing 27 is a coil 31 in which the gaseous
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medium is heated to increase its pressure and ~pecific heat.
Valve 32 prevents th~ backward flow of gaseous medium from the
coil 31. The exhaust gases flow out of mani~old 22 through an
exhaust conduit 36 to a condenser, cooler, or radiator 37 where
the heat is reduced and the cooled medium is stored in a reservoir
tank 38 for recirculation through the coil 31.
The foregoing is a stirling-cycle engine in that the
heated gaseous medium drives a piston and the gaseous medium from
the previous cycle of rotation i9 exhausted and condensed or at
leas~ cooled before being reheated and recycled. The combustion
in burner 26 is external to the engine 11 and hence a more complete,
efficient, pollution-free combustion is achieved. The gaseous
medium may be o various gases and vapor~ including air, hydrogen,
helium, steam, Freon~ etc.
Directing attention now to the details of engine 11, and
with specific reference to Figs. 2, 3 and 4, the engine block 12
intermediate to the ends of engine 11 are substantially identical
and the two end blocks 12a are complementary. As is apparent from
Fig. 3, the semi-toroidal cylinders formed in each block and in
each face of each intermediate blocX 12 are assembled side-by-side
and held together by bolts 41 which pass through all of the blocks
to form four cylinders 13. It will be understood that one or mor0
cylinders may be employed depending upon the desired capacity of
the engine. suitable bearings 42 in the blocks 12, 12a support
shaft 14 for rotation, the shaft 14 preferably being splined.
Each disk 16 has a hub 43 which turns with the shaft 14. on the
outside of each disk 16 is a belt-shaped seal ring 46. To complete
the seal of belt 46, a pair of annular belt seals or shoulders 47
is employed, the same being recessed into the blocks 12, 12a
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ZO~
immediately inside the belts 46. The shoulders 47 are held in
place by screws (not shown) or other means ~o that the shoulders
47 as well as the belts 46 may be replaced for wear a~ required.
The belt seal 46 turns with disk 16, and for such pur-
pose there is a substantially radial attachment 48 which secures
the belt 46 to the piston 17. A vent 49 is formed in the belt
46 to equalize the pre~sure when the main cylinder valve 18 is
about to ~pen 80 as to minimize the force of the main valve
opening.
The main valve 18 i~ opaned as the piston 17 passes
there-through. Various means may be used to time the opening of
main valve 18 but a simple means is herein illustrated. In this
embodiment, it is the motion of the piston 17 itself which opens
the main valve. For this purpose, the valve 18 consists of two
gate members 51 which are pivoted for opposite movement in the
blocks 12 or 12a. The inner edges of gates 51 are formed with
rabbets 52 so that they overlap and there is a gate seal 53 along
one or both of the rabbets 52. ~he gates 51 pivot on pintles 54
at the top and bottom, being rotatably mounted in the blocks 12,
12a. A helical spring 56 biases the upper pintles 54 downwardly
to keep the lower edges of the gates 51 in contact with the belt
seal 46 and walls of cylinders 13. RetUrn springs 57 hold the
gates 51 closed, said springs 57 being received in recesses 58.
The block~ 12, 12a are formed with openings 59 to permit the gates
to swing open from solid lina to dotted line position, as best
shown in Fig. 6. The forward nose 61 of piston 17 ic round and
the piston is provided with a chevron seal 62. The nose 61 of the
piston pushes the gates open and the springs 57 return same to
closed position.
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10~1201
The t~ps of the blocks 12, 12a are formed with horizontal
flats to which is bolted a valve plate 64 extending across all of
the blocks. Above plate 64 is a valve chest 66 in which the intake
and exhaust manifolds 19, 22 are formed with partition 65 there-
between. Bolts 67 hold down the chest 66. In plate 64 are valve
seats 68. The valve stems 69 extend upward from valves 21 and are
biased to seat on the seats 68 by valve springs 71 surrounding the
stems 69 and bearing against the underside of chest 66. ThUs there
is an inlet port 72 between inlet valve seat 68 and cylinder 13 to
one side of the main cylinder valve 18 and an exhaust port 73 com-
municating from the cylinder 13 to the exhaust manifold 22.
Rotatable in timed relat~n to shaft 14 is a cam shaft 76
mounted by means of pillow blocks 77 and sleeves 78 on shaft 76
and bolted to the top of chest 66. The left-hand end of shaft 76
(as viewed in Figs. 2 and 3~ is formed with a splined section 79.
PUlleys 81 are mounted on shafts 76 and 14 and interconnected by a
belt 82. Upper pulley 81 is fixed to sleeve 78 by a key on other
means.
For each of the cylinders 13 there is a cam 86 mounted on
shaft 76 and the location of the cam 86 determines the timing of
the various cylinders which is preferably a 1-3-4-2 cycle. The
development of each cam is best shown in Figs. 9 and 10. In the
form of cam shown in Fig. 10 there is a high dwell 87 which extends
around most of the circumference of cam shaft 76 and a low dwell
88 for about 20 degrees. The low dwell 88 insures that the valve
21 is closed as the piston 17 pas~es through the cylinder main
valve 18. As best shown in Fig. 9, one edge 89 of the cam high
dwell 86 is straight while the other edge 91 is slanted and beveled.
As hereinafter appears, the cams 86 are movable axially with the
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shaft 76 and the position which they have at any instant deter-
mines how long the valve 21 is opened.
To move the cams 86 (and their shaft 76) axially, one
end of shaft 76 is formed with a collar 92 against which bears a
clevis type lever 93 mounted in bracket 94 on one of the end
blocks 12a. ~od 96 extends to a hand or foot control which govern~
the speed of the engine. By pushing the rod 96 ho the left, as
viewed in Fig. 2 and 3, the shaft 76 is pulled to the right,
pulling the cams 86 therewith. The shaft 76 is returned by means
of return spring 97 which surrounds the shaft 76. one end of the
spring 97 bears on a collar 98 attached to shaft 76 and the other
bears against a stationary abutment 99 fixed to chest 66.
For each valve 21 there is a cam follower 101 attached
to the upper end of valve stem 69. The follower 101 is held in
place by a hold-down 102 bolted to pillow blocks 77. ThUs the
follower 101 fo~ows the high and low dwells of cams 86. As viewed
in Figs. 2 and 3, ~he farther the shaft 76 is to the right, the
longer the followers 101 are in engagement with the high dwell 87
of the cams and the longer the valves 21 are opened. ThUS by
mean~ of rod 96 the engine is controlled in the sense that gaseou~
fluid is admitted to each cylinder 13 behind piston 17 for a ~hort
or longer portion of the cycle of rotation of the piston depending
upon the portion of the cycle when follower 101 is in engagement
with the high dwell 87 of cam 86.
OP~RATION
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A gaseous medium i~ installed in the lines and cavities
of the system up to hundred~ of atmosphere~ pressure. Then burner
26 i~ ignited and heats the gaseous medium in coil 31 causing the
multiplied pressure of the medium to pass to the intake manifold
al
19 through intake port 72 and thence for a portion cf the cycle
of rotation of the engine into the cylinder 13, drivin~ the
piston 17 before it and thus causing the disk 16 to rotate the
shaft 14. The ~ain valve 18 is, of cour~e, closed during all of
the power stroke of the piston 17. The spent gases from the
previous cycle are discharged through exhaust port 73 into mani-
fold 22 and thence to cooler or condenser 37 where the gas is
cooled and condensed and returned to supply tank 38 to begln
another cycle.
As the piston 17 passes through the main valve 18, it
swings the gates 51 in Fig. 5 about their pintles 54 to open
position; but as soon as the piston 17 has passed the main
valve 18, the springs 57 return the gates Sl to closedpposition.
It will be understood that the gates 51 may be controlled by
other means.
speed control is achieved manually or pedally by moving
the rod 96 in Fig. 3 causing the clevis lever 93 to move the shaft
76 to the right and the spring 97 to return it toward the left.
Depending upon the position of shaft 76, the cam follower 101
comes into engagement with the high dwell of the cam 86 and more
particularly its slanted edge 91 and this raises the valve 21
against the force of spring 71 which tends to return it. when
the follower 101 engages the low dwell 88, the valve 21 is closed.
The valve 21 is always closed as the piston 17 passes through the
main valve 18. Further~ to equalizei~lpressure on both sides of
main valve 18, the pressure in cylinder 13 leak~ through vent 49
in seal 46, going under main valve 18 to exhaust port 73 as viewed
in Figs. 4 and 5.
