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
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 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
"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
"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 --
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
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"
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
Murry Deane Harper
-- 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
Current U.S. Class: 123/245 ; 123/43R;
Current International Class: F01C 3/06
(20060101); F01C 3/00 (20060101); F02B 75/02 (20060101); F02b
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
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
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
is a section
through the rotary engine taken along section line I--I of FIG.
is an elevation
of the engine with the housing removed;
is a section
taken along section lines II--II of FIG. 1;
is a partial
section taken through the rotary engine illustrating the piston
member-partition member relationship;
is an isometric
of the piston member;
is an end view of
the piston member;
is a section
taken along section lines VI--VI of FIG. 5;
is a section
through the piston carrier showing the operation of the inlet
is an end view of
the partition member and the seals therefor;
is an end view of
the partition member showing the milled out portion;
is a section
through another embodiment of my rotary engine illustrating
different faces of the pistons; and
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
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
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
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,
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
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
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
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.