U.S. patent number 3,895,620 [Application Number 05/312,042] was granted by the patent office on 1975-07-22 for engine and gas generator.
Invention is credited to Berry W. Foster.
United States Patent |
3,895,620 |
Foster |
July 22, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Engine and gas generator
Abstract
A synchronizing device in a two-cycle piston-cylinder
combination which acts as an engine to provide shaft power or,
alternatively, as a gas generator to provide turbine power.
Inventors: |
Foster; Berry W. (Redondo
Beach, CA) |
Family
ID: |
26751083 |
Appl.
No.: |
05/312,042 |
Filed: |
December 4, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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70387 |
Sep 8, 1970 |
3712276 |
Jan 23, 1973 |
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Current U.S.
Class: |
123/197.1;
123/46R; 123/55.7; 123/51R |
Current CPC
Class: |
F02B
75/243 (20130101); F02B 75/04 (20130101); F02B
71/06 (20130101); F02B 2075/025 (20130101); F02B
1/04 (20130101) |
Current International
Class: |
F02B
71/06 (20060101); F02B 75/00 (20060101); F02B
75/04 (20060101); F02B 75/24 (20060101); F02B
71/00 (20060101); F02B 1/00 (20060101); F02B
75/02 (20060101); F02B 1/04 (20060101); F02b
077/00 (); F02b 075/24 () |
Field of
Search: |
;123/197C,46R,46B,51BB,51BA,51B,51R,56R |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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558,115 |
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Dec 1943 |
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GB |
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525,274 |
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Aug 1940 |
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GB |
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557,206 |
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Nov 1943 |
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GB |
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568,588 |
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Apr 1945 |
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GB |
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731,627 |
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Jun 1955 |
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GB |
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240,519 |
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Apr 1946 |
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CH |
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Primary Examiner: Burns; Wendell E.
Attorney, Agent or Firm: Owen, Wickersham & Erickson
Parent Case Text
This application is a division of application Ser. No. 70,387,
filed Sept. 8, 1970, now U.S. Pat. 3,712,276 issued Jan. 23, 1973.
Claims
Having now described the invention, I claim:
1. In an opposed-piston engine including a first piston, a second
piston, a cylinder having first and second ends, each said piston
having a sliding surface engaging said cylinder, said pistons
having facing heads and opposite ends distant from said heads, and
means to introduce gas and air into said cylinder, said pistons
being adapted to reciprocate toward and apart from each other in
said cylinder, the improvement comprising:
synchronizing means for causing said pistons to reciprocate and
comprising
four crankshafts centrally and symmetrically located near said head
end and having cranks thereon and two single-branched connecting
rods for each piston, each said connecting rod being connected
respectively to a separate said crankshaft, the midsections of said
cranks and rods being positioned to move in the same plane, and
symmetrically located with respect to said synchronizing means,
means for causing said crankshafts to cause said pistons to
reciprocate in opposite directions to each other so that said
pistons and synchronizing mechanism are dynamically balanced.
2. The engine of claim 1 wherein said last-named means for causing
comprises a gear train joined to each said crankshaft and in
driving relation therewith.
3. A dynamically balanced opposed-piston engine exhibiting minimal
side loads on its pistons in operation, having a first piston, a
second piston, a common cylinder for said pistons, a common
centrally located combustion chamber, and synchronizing means
comprising:
a. a first said connecting rod pivotally affixed to said first
piston at one end and to a first crank at its other end,
b. a second connecting rod pivotally affixed to said first piston
at one end and at its other end to a second crank,
c. a third connecting rod pivotally affixed at one end to said
second piston and at its other end to a third crank,
d. a fourth connecting rod pivotally affixed at one end to said
second piston and at its other end to a fourth crank,
e. said first and second cranks rotating counter to each other when
in operation,
f. said third and fourth cranks rotating counter to each other when
in operation,
g. said first and third cranks being located adjacent to each other
and rotating counter to each other when in operation,
h. said second and fourth cranks being located adjacent to each
other and rotating counter to each other when in operation,
i. said first and fourth cranks being located diagonally with
respect to each other and rotating in the same direction and said
second and third cranks being located diagonally with respect to
each other, and rotating in the same direction,
j. all said cranks being positioned symmetrically to each other
with respect to a center point of said common cylinder,
k. a separate crankshaft affixed to each said crank, all said
crankshafts rotating at the same speed,
l. all said connecting rods lying in and moving in a single plane,
which plane also includes the centerline of said common
cylinder.
4. A dynamically balanced opposed piston engine combination
comprising a plurality of the engines of claim 3 connected in
series and wherein
said crankshafts are so connected together that the combustion
cycle of each engine is equi-angularly out of phase with each other
of said engines to provide more uniform shaft power.
5. Combination as in claim 4 wherein two of said engines are so
connected and said combustion cycles are 180.degree. out of
phase.
6. Combination as in claim 4 wherein three of said engines are so
connected and said combustion cycle is 120.degree. out of
phase.
7. The engine of claim 3 wherein all four said connecting rods are
identical and interchangeable members.
8. The engine of claim 3 wherein all four of said cranks are
identical and interchangeable and all four of said crankshafts are
identical and interchangeable.
9. The engine of claim 3 wherein said first and second pistons are
identical and interchangeable.
10. An engine as in claim 1 being dynamically balanced and
exhibiting minimal side loads on said pistons when in operation and
wherein said synchronizing means comprises:
a. a first connecting rod pivotally affixed at one end to said
first piston and to a first rocker arm at its other end,
b. a second connecting rod pivotally affixed at one end to said
second piston and at its other end to said first rocker arm at its
other end,
c. a third connecting rod pivotally connected to said first piston
at one end and to a second rocker arm at its other end, and
d. a fourth connecting rod pivotally affixed at one end to said
second piston and at its other end to said second rocker arm
whereby said second piston is adapted to reciprocate counter to
said first piston in operation,
e. said first and second rocker arms being positioned to rock in
the same plane and being adapted to rock counter to each other to
minimize said side forces.
11. An internal combustion engine comprising in combination:
a. an engine cylinder having a wall and a head end,
b. means to introduce gas into said cylinder,
c. an engine piston adapted to reciprocate in said cylinder and to
compress said gas therein, said gas then limiting the stroke of
said piston toward said head end,
d. a first rocker arm,
e. a first connecting rod extending generally in the same direction
as said cylinder and connecting said piston and said first rocker
arm to form an extended toggle to limit the stroke of said piston
in a first direction,
f. a second rocker arm, and
g. a second connecting rod extending generally in the same
direction as said cylinder and connecting said piston and said
second rocker arm to form an extended toggle to limit the stroke of
said piston in said first direction,
h. said first and second rocker arms being positioned to rock in
the same plane and being synchronized to rock counter to each
other, said plane also including the centerline of said cylinder,
whereby toggle link forces on said first and second connecting rods
normal to said cylinder wall are balanced on said toggle links to
prevent high side forces from acting on said cylinder.
12. An engine comprising:
a. a cylinder,
b. a first piston and a second piston adapted to reciprocate
therein counter to each other,
c. a first connecting rod affixed at one end to said first piston
and at its other end to a first crank,
d. a second connecting rod affixed to said first piston at one end
at its other end to a second crank,
e. a third connecting rod affixed at one end to said second piston
and at its other end to a third crank,
f. a fourth connecting rod affixed at one end to said second piston
and at its other end to a fourth crank,
g. said cranks all being positioned to rotate in the same
plane,
h. said first and second cranks being synchronized to rotate
counter to each other and said third and fourth cranks being
synchronized to rotate counter to each other, whereby the
respective connecting rod forces acting normal to said cylinder
will be balanced in operation,
i. said first and second and said third and fourth cranks being so
synchronized that said first and second pistons reciprocate to each
other.
13. An engine comprising:
a. a cylinder,
b. a first piston and a second piston adapted to reciprocate
therein counter to each other,
c. a first connecting rod affixed at one end to said first piston
and at its other end to a first crank,
d. a second connecting rod affixed to said first piston at one end
and at its other end to a second crank,
e. a third connecting rod affixed at one end to said second piston
and at its other end to a third crank,
f. a fourth connecting rod affixed at one end to said second piston
and at its other end to a fourth crank,
g. said connecting rods and said cranks all being positioned to
move in the same plane,
h. said first and second cranks being synchronized to move counter
to each other and said third and fourth cranks being synchronized
to move counter to each other, whereby the respective connecting
rod forces acting normal to said cylinder will be balanced in
operation,
i. said first and second and said third and fourth cranks being so
synchronized that said first and second pistons reciprocate counter
to each other.
Description
SUMMARY OF THE INVENTION
This invention relates to improvements in a two-cycle
piston-cylinder combination which can act as an engine to provide
shaft power or as a gas generator to provide turbine power, or
which can be useful for other purposes.
Thus, one object of this invention is to eliminate the need for
sleeve ports to scavenge a two-cycle engine. This novel scavenging
means may be used in a single piston with a cylinder head; it can
also be used in opposed-piston arrangements. For a single piston,
my new engine may be scavenged and charged through the piston head
by employing a valve arrangement similar to the one shown by FIGS.
7-13 of my U.S. Pat. No. 3,340,854. The improvement over that
patent is an exhaust channel which may be provided inside the
piston cylinder to eliminate the need for sleeve ports; thus, the
piston can be lubricated and its seal rings hold the oil
consumption to as low a rate as is achieved by the best four-cycle
engine. Another arrangement of the single piston engine may use a
combination of the cam-operated poppet-valves in the cylinder head
and the inertia-operated valves in the piston head with exhaust
channels inside the piston to provide larger intake and exhaust
port areas than most four-cycle engines have. The opposed-piston
arrangement may be provided with an intake valve in one piston and
an exhaust valve in the opposite piston with an exhaust channel
inside this piston. This opposed-piston arrangement will have
unidirection scavenging with no oil-consuming sleeve ports.
Another feature of this invention is an improvement on the
inertia-operated valve shown in my U.S. Pat. No. 3,340,854, to
provide means for locking the valve closed until it approaches its
crank end. For an engine with large pistons and long strokes, the
inertia-operated valve is the preferred design. When the engine
pistons are small and their strokes short, a valve located in the
piston with a cam-opening device in the engine housing is the
preferred design.
The two-cycle engine of this invention may be used to produce shaft
power directly by means of a piston driven mechanism, or it may be
used to generate compressed air and hot exhaust gases which may be
expanded through a gas turbine to produce shaft power.
This engine or gas generator is unique in that it may employ a
semi-free piston. The piston may be free to adjust the stroke for
the compression ratio at the engine head end for compression
ignition; however, at the crank end of its stroke, the piston may
be limited by a toggle action of its oscillating crank action. The
volumetric efficiency of the compressor for this semi-free
compressed gas generator will be higher than the corresponding
value obtained in the conventional free-piston engine.
This oscillating crank or toggle mechanism makes it possible to
employ a rotating or an oscillating flywheel instead of a recoil
piston to drive the engine piston to compression ignition
pressures. The flywheel may be geared to rotate or oscillate at
several times the frequency of the oscillating pistons, thus it
will be more effective for a given mass inertia. The semi-free
piston will have a wider operating speed range than a free-piston
engine with a recoil piston.
In the current crank-and-rod engines there is considerable side
load on the piston and cylinder walls when the high-pressure gases
act on the piston during its expansion stroke. This invention uses
a novel arrangement of two counter-rotating cranks and rods on each
piston in an opposed-piston engine to eliminate practically all of
this high side load from the piston and cylinder; thus the piston
will have less drag and wear. The connecting rods and cranks are
phased so that the side load is equally distributed between them
and goes directly into the connecting rod and crank bearings. This
unique means of eliminating side loads from pistons may also be
used in my semi-free piston engine. In the semi-free piston engine
with counter-oscillating levers and in the crank-and-rod engine
with two counter-rotating cranks and rods on each piston, the
resultant force on the rods is designed to go through the center
line of the piston cylinder.
This invention describes an opposed-piston engine which is
dynamically balanced, and it has little or no side loads on the
piston due to pressure forces. A standard building block concept
may be used to increase the power output and give more uniform
torque for larger engines. For example, a standard opposed-piston
engine block of this invention can produce 100 horsepower. Two such
engines can be coupled together and phased 180.degree. apart to
produce 200 horsepower. Three opposed-piston engines can be coupled
together and phased 120.degree. apart to produce 300 horsepower,
etc.
This invention also relates to improvements in piston gas
generators.
One of the weaknesses of the free-piston gas generator is that it
has to generate the full charge of compressed gas for each stroke,
even at slow idling speeds when this charge is not needed. Also,
the frequency range of the free-piston engine is very narrow, and
it cannot operate at slow speeds as can a diesel or an Otto engine.
The gas generator of this invention as well as my piston gas
generator of U.S. Pat. No. 3,143,850 can be converted to simple
diesel engines which idle at slow speeds and do not have to
generate any high-pressure gases or low-pressure gases. My two
types of gas generators, which may be converted to simple diesel
engines, are more efficient than a free-piston gas generator
especially for interrupted and variable speed mobile power
applications such as trucks, buses, automobiles, tractors, trains,
etc.
This invention also features an engine which has better thermal and
combustion efficiencies than the present diesel and Otto engines.
Also, because of the charging through the pistons, there will not
be any blow-by gases in the engine crankcases. Thus the engine of
this invention generates consideraly less smog than the present
diesel and Otto engines. After-burning can be provided if desired,
in the low pressure piston motor to insure complete combustion.
This after-burning will heat gases that are expanded to do useful
work.
BRIEF DESCRIPTION OF DRAWINGS
In the drawings:
FIG. 1 is an elevation view partly in section and partly in phantom
to show the piston positions of a semi-free opposed-piston engine,
according to this invention, when the pistons have reached their
closest-together position and the high-pressure gases in the common
cylinder force the pistons to move apart. The synchronizing
mechanism is cut away.
FIG. 2 is a view like FIG. 1 with the rocker arm and connecting
rods in their extending straight line toggle position to limit the
outward stroke of the pistons.
FIG. 3 is a view like FIG. 1 in which the rocker arm has rocked to
a position which is counter to the one shown by FIG. 1 and also
showing a synchronizing gear train.
FIG. 4 is a section view taken along line 4--4 of FIG. 3, showing
additionally how the gear train may be used to synchronize the
rocker arms with their respective rods on the opposite sides of the
engine cylinder. The rotating speed of the flywheels is highest
when the rocker arms are in their straight line extended toggle
position of FIG. 2; thus the flywheels may use their stored kinetic
energy to force the two small pistons to compress air in their
common cylinder.
FIG. 5 is a sectional horizontal view of an opposed-piston
two-cycle engine having a common cylinder, two pistons therein,
inlet means in one piston head and exhaust means in the other
piston head, and means for sealing the piston so that the flow of
oil into the engine cylinder is restricted to a minimum.
FIG. 6 is a schematic plan view of a crank-and-rod opposed-piston
engine with a turbo-charger, taken on line 6--6 of FIG. 7, with
both sides of the cylinder shown to include all the synchronizing
gears and four crank-and-rod mechanisms to keep the large side
loads off the pistons and maintain the engine in dynamic
balance.
FIG. 7 is a sectional view taken on line 7--7 of FIG. 6, showing
the piston drive means and other features.
FIG. 8 is a flowsheet showing a power plant arrangement including
three opposed-piston engines according to this invention connected
in series to power a common shaft, and including a turbo-charger to
compress air feed and a turbine through which exhaust gases are
discharged.
DETAILED DESCRIPTION OF THE INVENTION
In FIGS. 1 and 2 there is illustrated a semi-free opposed-piston
engine 10 comprising a common cylinder 11 and opposed pistons 12
and 13 which reciprocate therein. The respective head ends 14 and
15 of these pistons are at their closest-together positions in FIG.
1, and the space 16 between these head ends is then filled with
gases under compression and under high pressure. Motion of the
pistons is synchronized by rocker arm 17 and connecting rods 18 and
19, the rod 18 being pivotally affixed to the piston 13 at the pin
21, the rocker arm 17 being pivotally affixed to a suitable support
on the cylinder wall 27 at a pin 22. There are also provided
compressor cylinders 23 and 24 which receive and support
cylindrical ends or bases 25 and 26 of the pistons 12 and 13,
respectively. The ends or bases 25 and 26 fit snugly and ride
freely within the cylinders 23 and 24, respectively. The kinetic
energy of the oscillating flywheel described below in relation to
FIG. 4 forces the pistons 12 and 13 toward each other again to
compress a fresh charge of gas which may be fed in at sleeve ports
or through the piston head 14 or 15 as shown in FIG. 5. It will be
understood that pistons 12 and 13 of the engine of FIG. 5 are
provided with wholly contained ducting means for inlet of air and
exhaust of gases and to prevent contact of such gases with the
lubricated surfaces between the sliding contact surfaces of the
pistons 12 and 13 and the interior wall 27 of the cylinder 11, as
described elsewhere herein, but that those and other elements are
omitted from FIG. 1 for a clearer showing of the rocker arm and rod
means for synchronizing movements of the pistons.
The engine of FIGS. 3 and 4 is like that of FIGS. 1 and 2 but
includes a showing of a gear train suitable for oscillating power
take-off from the rocker arm 17, wherein a power shaft 30 is driven
by a gear 31 which in turn is driven by a gear 32 affixed to the
rocker arm 17 and thus driven thereby when the expansion of the
gases in the space 16 forces the arm 17 out to the position shown
in FIG. 2. In the drawings, like parts are designated by like
numerals. FIG. 4 is a view, partially in section, of the device of
FIG. 3, showing the arrangement of the driving and power take-off
mechanisms but omitting certain parts, such as the pistons, for
clarity. In this view, the cylinder 11, which is suitably supported
by means not shown, supports the shaft 30 by pedestals 33, 33'
having suitable bearings 34, 34' to receive a shaft 30. When the
rocker arm 17 is forced out by the expanded gases to the position
shown in FIG. 2, the energy released can be transmitted to a large
flywheel 35 for idling or to a small flywheel 36 for operating
speeds (with the large flywheel 35 then de-clutched) and thence to
a driven mechanism, e.g., through a device such as a scotch
crosshead 37, all controlled by means of conventional clutch
arrangements.
FIG. 5 illustrates an opposed-piston two-cycle engine 38 according
to this invention and shows the protected flow of gases
therethrough, the engine 38 comprising a housing 39, a common
cylinder 11 and pistons 40 and 40'. In each head 41, 41' of the
pistons is centrally disposed a port 42, 42' into which a valve
head 43, 43' seats, respectively. Disposed adjacent the cylinder 11
is a gear train comprising gears 44, 45, 46 and 47, of which the
gear 44 is affixed to a shaft 53 which bears on the cylinder 11,
the other end of the shaft 53 bearing a rocker arm 48; and the gear
47 is affixed to a shaft 53' which bears on the cylinder 11. The
other end of the shaft 53' is affixed to a rocker arm 48'.
Pivotally connected to the arm 48 are rods 49 and 49'; and to the
arm 48', rods 50 and 50'. At their ends remote from the arm 48, the
rods 49, 49' are pivotally connected to beams 51, 51' attached
respectively to the pistons 40, 40'. Similarly, the rods 50, 50'
are affixed to beams 52, 52' which are likewise affixed
respectively, to the pistons 40, 40', so that as the arms 48, 48'
move in synchronization about their central shaft pivots 53, 53',
the pistons 40 and 40' reciprocate accordingly counter to each
other within the cylinder 11. Within each piston 40, 40', is
disposed a smaller tubular body 75, 75' concentric and integral,
through spokes 87, 87', with the pistons 40, 40', and adapted to
receive and guide a stem 78, 78' attached to the valve head 43, 43'
in this embodiment. In this embodiment, the port 42 is the intake
port and the port 42' is the exhaust port. The pistons 40, 40' are
lubricated with suitable liquid oil lubricant at an annulus 59, 59'
which is sealed by rings on the pistons 40, 40' and the cylinder
11; and it can be seen that the path of heated exhaust gas prevents
substantial contact thereof with the lubricant, thus avoiding
substantial cracking or degradation of the latter.
In the operation of this engine 38, air or an air-fuel mixture is
fed through the piston 40 and its port 42 into a central space 83.
When the pistons approach their mid-inward stroke position the
valves 43 and 43' are closed and the trapped gas is compressed as
the pistons 40 and 40' move further toward each other. As the
closest-together position of the heads 41 and 41', both of the
valves 43 and 43' are still seated in their respective ports 42 and
42', and the compressed gas can be combusted by conventional fuel
injection (not shown) or conventional spark ignition (not shown) to
generate heat and gaseous products of combustion, forcing the
pistons 40 and 40' to move apart, the valves 43 and 43' remaining
closed until the pistons 40 and 40' approach their furthest apart
position. Then the port 42' is open to withdraw the gaseous
products of combustion, which flow outward through the piston 40'
and are removed; and the port 42 opens to admit a fresh charge
which scavenges the exhaust gas remaining in the space 83. The
opening of these valves 43 and 43' will be further described later
herein.
As the pistons 40 and 40' recede from each other, the beams 51 and
51' attached thereto, respectively, are forced away from each other
and, being connected to the arms 48 and 48' by way of the rods 49,
49', 50, 50', force the arms 48, 48' to assume a position parallel
to the axis of cylinder 11 at the farthest-apart position of the
heads 41 and 41'. At this time, the ports 42 and 42' are fully
open. The pistons 40 and 40' then begin to approach each other
again, actuated by the flywheel 36 shown in FIG. 4 for normal
speeds. The large flywheel 35 may be clutched in for idling
speeds.
As the pistons 40 and 40' move apart as described above, and extend
the arms 48 and 48', the gears 44 and 47 are actuated, and these in
turn actuate the gears 45 and 46 which actuate, respectively,
oscillating power take-off shafts 85, 86. When the arms 48 and 48'
and the rods 49, 49' and 50, 50' are in their extended position the
oscillating flywheel 36 is rotating at its maximum speed; thus the
kinetic energy in the flywheel 36 will turn the shafts 53 and 53'
and the arms 48 and 48' to drive the pistons 40 and 40' together to
compress another charge, the recoil action of the compressed charge
absorbing the full kinetic energy of the flywheel 36. In an
advantageous embodiment the gears are, or the gear train is,
adjusted so that the flywheel 36, which is an oscillating flywheel,
oscillates at a higher frequency than that of the rocker arm 48 and
rod 49, preferably several times that of the latter.
FIG. 6 is a schematic plan view of the opposed-piston crank-and-rod
engine shown in FIG. 7, FIG. 7 being taken on line 7--7 of FIG. 6,
such engine comprising the engine housing 39, the common cylinder
11, opposed pistons 54, 54', gears 55, 56, 57, 58 and 55', 56', 57'
and 58'; and rods 71, 71' and 73, 73', pivotally attached to,
respectively, beams 72 and 72' at one end of each such rod and to
cranks 67, 68, 67' and 68', respectively, at the other end of each
such rod. In an exhaust line 88 from the piston 54 are disposed
turbo-chargers 89 and 90. The crank 67 and the gear 55 are fixed to
a shaft 67a. The crank 68 and the gear 58 are fixed to a shaft 68a.
The gear 56 is keyed to a shaft 56a and the gear 57 is keyed to a
shaft 57a. The shafts 67a, 56a, 57a and 68a have their bearings on
the engine housing 39, and each can be used to transmit power. In
like manner, the crank 67' and the gear 55' are fixed to the shaft
67'a, and the crank 68' and the gear 58' are fixed to the shaft
68'a; the gears 56' and 57' are keyed to the shafts 56'a and 57'a,
respectively; and such shafts have their bearings on the engine
housing 39, and each shaft can be used to transmit rotating shaft
power in one direction.
FIG. 8 is a flowsheet showing as an example an arrangement
comprising of crank-and-rod building block engines where three
opposed piston engines as indicated operate a common rotating shaft
for power in one prescribed direction of rotation, and gaseous
exhaust products are fed through the turbine of a turbocharger to
operate the supercharger which provides compressed air to the
engine intake.
The above specific description and the drawings have been given for
purposes of illustration and variations and modifications can be
made therein without departing from the spirit and scope of the
appended claims. Where an element is described as pinned to another
element, it will be understood that such element is pivotally
attached thereto.
* * * * *