M. Deane Harper of Dunbar WV has invented a rotary engine surpassing
anything all the money and engineering breainpower of Detroit could
come up with. Good, old-fashioned American ingenuity and inventiveness
triumph again !
Harper, a machinist, mechanical engineer and teacher who has a number
of inventions to his credit, has developed a rotary engine far superior
to the famed Wankel the made Mazda's go hmmm, but also fizzled due to
inherent engineering shortcomings.
One doesn't have to be an expert to realize that an efficient rotary
engine is far superior to the present day piston engines. However, it
remains to be seen whether the Harper rotary has come along too late in
the heyday of gasoline-driven motors.
On the other hand, Harper stresses his rotary engine will run well on
steam and would be an excellent turbine motor, too.
The Harper design has unlimited potential. The inventor's partner,
Robert Weidlich of Charleston WV said:
"The number of desriptive names for this engine is readily outnumbered
by the vast potential of use for this new mechanism that changes
expanding gas pressure to rotary motion more efficiently than any other
design".
Harper has obtained his patent: # 3,809,025.
The inventor and his partner drove from West Virginia to Chicago a few
weeks ago just to show this reporter the working prototype. "You can't
very well write about something you haven't seen", Weidlich emphasized.
The four cylinder, gasoline-driven rotary spins like a flywheel when it
runs. The entire engine rotates.
"It's a rough prototype that we run for only a few minutes at a time
because we've not designed any cooling system", Harper explained. "I
built it from scrap materials found around my machine shop".
While my knowledge of engines is limited, I do know enough to
understand that I was viewing an important moment in engine history as
the Harper rotary whirred into action.
The future of the gasoline powered engines may be in doubt, but there's
no doubt they'll be around at least a decade or two longer and harper's
invention appearsto be the highest state of the art.
The working model was built to prove to doubting patent office
officials that the design worked. Then it was transported to Denver
where scientists from the University of Denver, Denver Research Instite
analyzed it.
Dr Charles Lundin and engineer Frank Lynch signed the report which
conlcuded:
"The Harper Rotary Engine is difficult to conceptualize at first
exposure, but in truth, is very simple in its operating principles.
Since all the surfaces in the engine are circles, spheres or cones, it
should not be difficult to produce the parts of the engine with
standard machine tools.
"The engine is considerably more compact than standard internal
combustion engines and aside from a secondary speed oscillation in the
pistons, it is vibration-free.
"The seals in the combustion chamber at any given radius sweep though
circular arcs over a constant radius surface through circular arcs over
a constant radius surface segments at speeds well within the
performance limits of conventional piston rings. If the unusual
geometry of the piston causes difficulties in using standard piston
ring-type seals, then surely the Wankel-type seals would be more than
adequate.
"A cursory mechanical analysis disclosed no unmanageable stress
problems. The piston pins in te prototype, however, need to be enlarged.
"One of the most significant features of the engine is its variable
compression ratio. By maintaining the highest permissible compression
ratio under all operating conditions, average operating efficiencies
may be significantly improved"
The report was stiffly scientific, but the researchers managed to make
suggestions for minor engineering improvements which indicated their
enthusiasm for the device.
"The original concept was slow in taking shape because of the unique
surfaces", Harper explained. "The conical surfaces are parallel,
perpendicular to and at 90 degrees to the center of the output shaft".
But then, after constructing the model, Harper realized he had one of
the simplest engines ever built.
Weidlich listed the possibilities of this Harper design:
"It can be similar to a 2-cycle, or it can run as a 4-cycle gasoline
engine; it can operate as a diesel; a Rankin cycle steam engine; a
steam turbine or a Sterling engine".
Harper and Weidlich, who are knowledgeable automotive engineers, are
certain that their concept of a "positive displacement turbine" will be
the greatest imprvement in using steam for motive power since James
Watt's engine.
"The positve displacement turbine would have the torque of a steam
engine and the low speed of a turbine".
While the technical merits of future production models need to be
tested and proved, it is easy to see that as a gasoline-powered engine,
the Harper Rotary offers a power-to-weight ratio most appealing to the
aircraft industry -- especially helicopters.
If there are any drawbacks to getting this invnetion into production
and out into the marketplace to serve our nation, it appears to be in
the area of the automotive aftermarket.
Harper's engine will not wear out like today's cumbersome Otto-cycle,
piston-driven creatures. Costly repairs and the need for replacement
parts will be virtually eliminated.
The consumer can hail this event with enthusiasm -- but not so the
national economy.
Since any new invnetion takes time to move from prototype to
production, it seems the industrial complex should be able to adjust to
the efficiency -- however, a realist will suggest that many jobs and
businesses supportive of today's aftermarket will die natural deaths.
To get a partial idea of the impact that could generate if all
automobiles suddenly switched to the better engine, consider that
Harper's rotary engine has:
-- No parts that stop, start, or change directions...
-- No flywheel...
-- No gears...
-- No distributor...
-- No valves, tappets, valve springs, or push rods...
-- No rocker arms...
-- No counter balances...
-- No crankcase...
-- No connecting rods..
-- No fan...
-- No radiator...
-- Perfect balance, variable compression, self-lubricating seals and
seals having a surface speed one-tenth of the problematical Wankel
seals.
Harper and Weidlich said they have also contacted machanix Illustrated
and other publications, but Exchange was the first to respond. It will
be interesting to see how the 'experts" handle it.
This is the beginning of a new era in automotives and this has been a
story with a moral.
The moral is: "Our nation would do well to once again rely upon
individual initiative, intuition and ability rather than suppress such
qualities with arrogance and waiver forms".
Technical Data for Experts --
Displacement -- 38 cu. in.
Bore -- Power segmetn equal to 2-7/8 bore
Stroke -- Angular running plane of power segments equal to a 1-1/2 inch
stroke
Firing Chambers -- 4, equal to 4 cyclinders...
Compression -- 6-1/2 to 1 variable...
Intake Vacuum -- 15 inches...
RPM -- Tested at 3200; capable of 20,000...
Physical Size -- 10-1/2 inch diameter; 5-1/4 inches wide, prototype
weight 55 lb; could be reduced to 35 lb...
Ignition -- 6 volts...
Balance -- perfect...
Heat -- Air-cooled...
Main Bearings -- Ball bearings...
Power Impulses -- 4 per revolution...
Horsepower -- no rate at this time, but with a 3 hp per cu. in. rating
this model would generate 114 hp. If we obtain the same hp as the
present day motorcycle engine, we would generate 120 hp...
Murry Deane Harper 
Robert Weidlich
Abstract -- The rotary engine
includes a housing which defines a plurality of chambers for primary
compression and combustion and a plurality of pistons mounted to a
piston carrier positioned within the housing. Both the housing and the
piston carrier rotate at the same rate on separate shafts and the axes
of rotation of the two shafts are at an angle to one another.
Combustible gas is fed through a central hollow portion of the piston
carrier shaft where it is directed into the primary compression chamber
by inlet means in the piston carrier which are exposed to the chamber
through the movement of the housing relative to the piston carrier.
Transport means communicate with each primary compression chamber to
transport the combustible gas around the piston from an inlet side to a
combustion side of the chamber.
May 7, 1974
Inventors: Harper; Murry D. (Dunbar, WV)
Assignee: Harper Development Corporation (Dunbar, WV)
Current U.S. Class: 123/245 ; 123/43R; 418/164;
418/68
Current International Class: F01C 3/06 (20060101);
F01C 3/00 (20060101); F02B 75/02 (20060101); F02b 053/00 ()
Description
BACKGROUND OF THE INVENTION
My invention relates to rotary engines and, more particularly, to
rotary engines in which the axis of rotation of the combustion chamber
is at an angle to the axis of rotation of the pistons.
Fluid pumps and motors are known in the art which operate on the
principle of rotating chambers and displacement elements wherein the
rotational axes are angularly displaced. Attempts have been made
heretofore to apply these principles to an internal combustion engine,
but these attempts have been directed to apparatus functioning in a
known four stroke cycle.
SUMMARY OF THE INVENTION
My invention utilizes the principle of the angular displacement of the
axes of rotation of chambers and pistons, but these principles are
adapted to operate in a manner similar to a two stroke cycle engine. My
invention provides a perfectly balanced engine in which pure linear
motion is transformed into rotary motion. The engine can be air or
liquid cooled. My engine provides variable compression and
self-lubricating seals. My engine provides high torque at low speeds
and there is no side thrust on the combustion chamber walls as is
produced on a standard piston engine by the angle of the connecting
rod. The efficiency of the engine and the power curve are such that the
size and weight of the engine can be substantially less than existing
rotary engines for a given horsepower. During operation, no parts stop,
start, wobble or change direction. My engine is an improvement on
existing engines from the standpoint of pollution control in two
respects. Since the main bearings are sealed ball bearings mounted
external of the engine and there is no lateral thrust of the piston on
the chamber walls, less oil is required and, therefore, there is less
burning of hydrocarbons. In addition, the surface area of the
combustion chamber wall to the cubic inch displacement is easily
controlled so the engine can be operated at a lower flame temperature
than existing engines, thereby reducing the nitric oxide emissions. As
a result of the spherical and conical shapes of the engine components,
the seal mechanisms are greatly simplified over known rotary engines
and line contact seals can be easily employed.
My invention is a rotary engine in which the combustion chambers and
the pistons rotate on separate axis with the axes being at an angle to
one another. Transport means direct the combustible gases around the
pistons in each chamber during the engine cycle so that the operation
of the engine is similar to a two stroke cycle engine. The pistons are
mounted on a spherical piston carrier which also receives the
combustible gas and directs it into the chambers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section through the
rotary engine taken along section line I--I of FIG. 3;
FIG. 1a is an elevation of the
engine with the housing removed;
FIG. 2 is a section taken along
section lines II--II of FIG. 1;
FIG. 3 is a partial section
taken through the rotary engine illustrating the piston
member-partition member relationship;
FIG. 4 is an isometric of the
piston member;
FIG. 5 is an end view of the
piston member;
FIG. 6 is a section taken along
section lines VI--VI of FIG. 5;
FIG. 7 is a section through the
piston carrier showing the operation of the inlet ports;
FIG. 8 is an end view of the
partition member and the seals therefor;
FIG. 9 is an end view of the
partition member showing the milled out portion;
FIG. 10 is a section through
another embodiment of my rotary engine illustrating different faces of
the pistons; and
FIG. 11 is another section
through the embodiment illustrated in FIG. 10.
The principles described hereinafter can be applied to pumps, fluid
motors and compressors, but are disclosed for the preferred embodiment,
a rotary combustion engine.
The engine, generally designated 10, includes a housing 11 and a piston
carrier 14, both of which rotate at a common speed, FIGS. 1-3. Housing
11 is annular in shape and has a concave inner surface 17 defined by a
segment of a sphere. A top cover plate 12 and a bottom cover plate 13
are bolted to the housing 11 by a plurality of bolts 25 and 26,
respectively. Each cover plate 12 and 13 is defined by inner conical
walls 27 which terminate in a concave socket 28 which is also a segment
of a sphere. Shaft 19 connects to cover plate 13 through a plurality of
bolts 20. Shaft 19 represents the power take off for the rotary engine
10.
Piston carrier 14, which is a complete sphere, is positioned within the
housing 11 and in operable engagement with concave sockets 28 of the
top and bottom cover plates 12 and 13, respectively. Seals 53 in cover
plate 12 engage the piston carrier 14. Rigidly secured to the piston
carrier 14 is shaft 21 which extends outward through an appropriate
opening in the top cover plate 12. Shaft 21 is hollow and includes a
central passageway 22 which communicates with chamber 23 located
internal of the piston carrier 14. Shaft 21 is positioned with respect
to shaft 19 so that the axes of rotation of the two shafts intersect at
an angle at the center of the piston carrier 14. This angle, as
measured in degrees from a coaxial position and represented by theta in
FIG. 1, is variable and will normally be between 5.degree. and
20.degree..
Partition members 16 are positioned within the housing 11 in spaced
apart relationship so as to form combustion chambers 35, the inlet side
being referred to as primary compression chambers 34, FIGS. 1--3. The
rotary engine 10 with four partition members 16 has four combustion
chambers 35. Each partition member 16 is substantially trapezoidal in
shape and includes a spherical concave inner surface 30 positioned for
slidable engagement with the piston carrier 14 and an outer convex
spherical surface 29 which cooperates with the inner surface 17 of
housing 11. Each partition member is rigidly connected to the housing
11 by four bolts (not shown) which extend through the housing and screw
into bolt holes 51 in the partition member 16, FIGS. 3 and 9. The
partition member 16 also has upper and lower concave spherical surfaces
48 which engage with the conical surfaces 27 of the cover plates 12 and
13, respectively, FIGS. 8 and 9. Sides 45 of the partition member 16
are convexly shaped so that sides 45 of adjacent partition members 16
define the extreme limits of the combustion chambers 35.
In other words, each combustion chamber 35 and primary compression
chamber 34 is defined by piston carrier 14, inner surface 17 of housing
11, conical walls 27 of the top and bottom cover plates 12 and 13,
respectively, and convex surfaces 45 of adjacent partition member 16.
Each partition member 16 includes transport grooves 33 which extend
along and are recessed in a portion of the surfaces 45 of the partition
member 16, FIGS. 1-3. As will be explained hereinafter, the transport
grooves 33 serve to transfer the gases from the primary compression
chamber 34 around the piston to each combustion chamber 35. Therefore,
as long as the grooves 33 perform this function, there can be a single
groove or a plurality of grooves and the two grooves 33 on each surface
45 for a total of four grooves per each partition member 16, FIG. 3, or
two grooves 33 for each partition member 16, FIG. 2, are exemplary only.
Operating within each combustion chamber 35 is a piston 15, FIGS. 1-6,
connected to the piston carrier 14. The piston 15 is also substantially
trapezoidal in shape and includes an outer convex spherical surface 31
which slidably engages the spherical inner surface 17 of the housing 11
and an inner concave spherical surface 32 which engages the piston
carrier 14, FIGS. 1-3. The side surfaces 46 of the piston 15 are
concavely shaped as segments of a sphere so as to slidably cooperate
with the convex sides 45 of adjacent partition members 16. The pistons
15 separate the chamber into the combustion chamber 35 and primary
compression chamber 34.
Each piston 15 is connected to the piston carrier 14 as follows. The
piston 15 includes a rectangular opening 39 extending through the
piston and terminating in a cylindrical opening 40 so as to form a
shoulder at the juncture thereof, FIGS. 1-6. Piston pin 37 provides the
connecting means and is circular in cross section, threaded at one end
to threadably engage the piston carrier 14 and has an enlarged head at
the other end to shoulder against the rectangular opening 39. A cross
sectionally square block 38 includes a cylindrical clear through
passageway which accommodates the cylindrical piston pin 37. The block
38 in turn is positioned within the rectangular piston opening 39 in
the piston 15. The walls of block 38 are tapered slightly inward from
the piston carrier end to the housing end. This tapered axial extent of
the block 38 provides increasing clearance in a direction away from the
piston carrier 14 and this clearance is necessary for the relative
movement of the piston 15 as rotation takes place, with the total
relative movement being not unlike a universal in that respect, FIG.
1a. The distance between common points along the center lines of
adjacent pistons 15 increases slightly as the adjacent pistons 15 move
from a position along the center line of the combustion chamber to a
position adjacent opposite ends of the combustion chamber, FIG. 1a.
This slight movement of the piston 15 is relative to the piston pin 37
and thus the piston carrier 14 is accommodated by the clearance formed
by the tapered walls of block 38.
Exhaust ports 18 extend through the housing 11 and communicate with
each combustion chamber 35, FIGS. 1-3. Spark plugs 36 extend through
the top cover plate 12 and through the conical wall 27 thereof into
communication with the combustion chamber 35.
The fuel mixture such as gas is fed from a carburetor (not shown) into
passageway 22 of the shaft 21 and into the chamber 23 internal of the
piston carrier 14. Four curved gas inlets 24 extend outward from
chamber 23 and an inlet 24 communicates with each of the four primary
compression chambers 34, FIGS. 1 and 7. These inlets 24 are opened and
closed by the relative movement of the piston carrier 14 with respect
to the socket 28 of the bottom cover plate 13. The curvature of the
inlets 24 matches the curvature on the socket 28 so that a maximum
exposure of the inlet 24 occurs and yet the opening can be immediately
closed, FIG. 7.
Each piston 15 is recessed about its periphery by slot 43 which
accommodates a piston ring. This piston ring slot 43 is positioned as
close to the combustion side face of the piston 15 as possible. Each
piston also includes on the combustion side face opposing deflector
notches 44 which serve two functions. Namely, the notches 44 place the
gases closer to the seal 43 thereby avoiding a wasted length of piston
movement. In addition, the shape of each notch directs the gas in a
loop scavenging stroke and away from the exhaust ports 18 as will be
described hereinafter.
In order to minimize the horsepower requirements on the inlet side of
the piston 15, the bottom surface 41 of piston 15 adjacent the inlet
port 24 is recessed by cutout 47, FIGS. 5 and 6. Cutout 47 may be
recessed in any desired shape to minimize the horsepower required in
the compression stroke in the primary compression chamber 34.
The partition members are sealed against the piston carrier 14 and
opposite sides of the piston 15 by seals 49 and 50 positioned in mating
slots recessed in surface 30 and in the form of a cross. Seal 50
extends into seal 49 so as to provide a lock for seal 49. In order to
reduce the weight of the engine, the partition member 16 may be
hollowed out such as by conical cutout 52 milled deeply into the
interior of partition member 16, FIG. 9.
The operation of my rotary engine 10 is as follows. As the shaft 21 and
shaft 19 rotate relative to and at an angle to one another, the piston
15 has the effect of moving back and forth in the combustion chambers
35 even though there is rotation in a single plane. The movement of the
piston 15 is between the opposing conical faces 27 of the cover plates
12 and 13, respectively. When the piston 15 is in the combustion
position, the gases have been compressed between the piston and the
conical surface 27 which accommodates the spark plug 36. The spark plug
36 rotates with the housing 11 and is easily fired through stationary
contact surfaces which are engaged by the spark plug 36 as it travels.
Combustion creates a thrust on the piston and housing and is directed
along the power take off in standard fashion.
At the same time the piston 15 is in the firing position, the inlet
ports 24 have been opened and the gases have been drawn into the
primary compression chamber 34. As the piston 15 moves away from the
site of the combustion, it continues to cover the transport grooves 33
thereby compressing the gases on the inlet side. This compression takes
place because the inlet ports 24 are closed and the transport grooves
33 have not as yet been exposed on both sides of the piston 15. This
latter circumstance continues until the products of combustion have
exhausted through the exhaust port 18, after which the piston 15
exposes the transport grooves 33 on opposing sides of the piston 15 and
since the gas is under compression it is caused to transfer to the
combustion side, namely combustion chamber 35. This process repeats
itself every revolution of the rotary engine 10 so that with the four
combustion chambers 35, the engine is firing four times per every
revolution. The transfer of gases from one side of the piston to the
other is somewhat similar to a two stroke cycle reciprocating internal
combustion engine. Of course, with the subject rotary engine, there is
no reciprocation of a piston since pure linear motion is transformed to
rotary motion.
My rotary engine 10 can be constructed in a number of ways, all of
which embody the principles described hereinbefore. A three power
impulse per revolution cycle is illustrated in FIGS. 10 and 11. The
housing 55 is in the form of a three leaf clover and has an interior
surface 56 defining three combustion chambers 60. The housing 55 is
constructed in three substantially equivalent segments and then joined
by means of bolts 58. Cooling fins 59 are bolted to the exterior of
housing 55 by means of bolts 86. A power take off shaft 81 is secured
by bolts to the housing 55 and functions in the same manner as shaft 19
of the earlier embodiment.
The housing 55, by being shaped in the form of a cloverleaf, eliminates
the partition members of the earlier embodiment. In addition, the
housing itself includes the interior concave socket 57 which
accommodates the spherical piston carrier 65. Piston carrier 65 is
rigidly connected to piston shaft 84 which contains hollow passageway
85 communicating with the inlet ports 68 in the piston carrier 65.
The housing 55 also includes exhaust ports 66 extending therethrough
from each combustion chamber 60. In addition, spark plugs 82 are
carried by the housing 55 and communicate with each combustion chamber
60. Transfer ports 67 are formed in the housing 55 so as to create a
bypass from one side of the piston (primary compression) to the other
(combustion) in the same manner as the earlier embodiment. Transfer
ports 67 can be milled into the housing 55 or can be separate duct work
secured to the housing. These transfer ports 67 perform the same
function as the transport grooves of the earlier embodiment.
Pistons 61, 62 and 63 are secured to the piston carrier 65 so that each
combustion chamber 60 has a single piston operable therein. Each piston
itself has a spherical concave end portion 70 which mates with the
spherical piston carrier 65 and a convex end portion 71 which slidably
mates with the spherical housing interior surface 56 at the end of each
combustion chamber 60. The pistons 61, 62 and 63 differ from the
pistons of the earlier embodiment in that each piston includes a flat
face 69 on the combustion side of the chamber and a flat face 72 on the
inlet side or primary compression chamber. These flat faces 69 and 72
approach corresponding flat faces of the housing interior surface 56
during operation in the combustion and compression portion of the cycle.
The pistons 61, 62 and 63 are connected to the piston carrier 65 in the
same manner as the earlier embodiment. Specifically, each piston
includes a rectangular cutout 75 into which is inserted a cross
sectionally square block 76 tapered along its length and which also has
a cylindrical opening clear through. Into the cylindrical opening is
inserted the cylindrical section 78 of piston pin 74 so that the piston
pin head 79 shoulders against the opening in the piston to hold the
piston in place.
An additional sealing and wear feature is illustrated in FIGS. 10 and
11 for the piston pin 74 and the pistons 61, 62 and 63 and such a
feature is equally applicable to the earlier embodiment. Piston pin
head 79 has a concave undersurface 87 which cooperates with a convex
washer 77 positioned against the shoulder formed at the termination of
the rectangular opening 75. The washer is hardened steel and acts as a
wear plate for the piston pin 74. This arrangement adequately holds the
pistons against the piston carrier 65 and prevents the piston through
centrifugal force from being forced against the inside surface 56 of
the housing 55.
The operation of the rotary engine illustrated in FIGS. 10 and 11 is
identical with that of the earlier embodiment except that the engine
has three power impulses per revolution instead of four.
The pistons are sealed in the same manner as the earlier embodiment.
Each piston includes a seal 80 extending abouts its entire periphery,
as illustrated by dotted lines for piston 62 in FIG. 10. More than one
seal 80 can be employed in spaced apart relationship about the
periphery, albeit only one such seal is illustrated.
Face 72 of piston 63 is inverted 180.degree., FIG. 10, for purposes of
illustrating the plurality of conical cutouts 73 which reduce the
weight of the piston and relieves the horsepower requirement of the
piston in the compression stroke.
The rotary engine 10 transforms pure linear motion to rotary motion in
a totally balanced system so as to obtain optimum performance with a
minimum of weight and moving parts.
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