CA2003491A1 - Rotary internal combustion engine - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A rotary internal combustion engine wherein the cylinders making up the engine block are radially disposed in a common plane and rotate with the output shaft. The engine block rotates within a surrounding cam surface and the pistons in each cylinder move radially in and out in a motion geometrically defined by connecting rods, a rocker arm pivoted at a point fixed with respect to the rotating engine block and a cam follower which rides on the cam surface. The rocker arm preferably is counterbalanced to reduce centrifugal forces on the cam surface. The cam surface is contoured to produce the motion to the pistons by means of the linkage as the engine block rotates. The engine block includes a rotary valve port associated with each cylinder. The engine block rotates into cooperating relationship with stationary inlet and exhaust ports in the engine housing to provide intake and exhaust cycles. The power stroke for each cylinder is radially outward and the piston drive linkage and cam slope are arranged to convert the radial forces into shaft torque. The engine has means for varying the compression during operation. A novel oil cooling system with centrifugally assisted circulation is also provided. The rotary engines can be selectively connected in series to form a multibank engine. The rotary engine of the present invention is ideal for powering light airplanes.

Description

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OTARY INTERNAL COMBUSTION ENGINE
Field of the Invention The present invention relates to ~nternal combustion engines and more particularly to rot~ry internal combu~tion engines where the ~ngine block hou~ing the cylinder~ ~s directly coupled t~ an output shaft and the engine block rot~te~ about the axis of ro~ation of the output shaft.
Back round of the In~ention The conventional internal combustion engine is one where the cylinder~, either in line or in a V-block, for instance0 have the cylinder connecting r~ds ¢onnec~ed to a erank shaft ~nd the crank shaf~ $~
rotatably dri~en by the combustion of the fuel ~ixture within the cylinders. ~he typical combustion cycle includes intake ~ an air-fuel mixture ~nto the ~ylinder, compression of the air-fuel mixture by the piston, combustion which causes a rapid expansion of the gases within the cylinder to drive the piston ~nd perorm work, and the subsequent exhaust stroke evacuating the products of ~ombustion. In a four ~troke crank-type engine, the power or expansion stroke occurs once in each 720 of rotation of the crank ~haft.
Thi~ conventional internal ~ombustion engine also requires an intake and exhaust valve ~or each ~ylinder which m~lst be timed to open and close in synchronization with the cycle of the pi~tons. The valves in a c~nventional internal combustion engine are poppet val~es whieh hav~ a stem ~nd ~ mushroom ~haped head with edges ~eating on the periphery of ~ valve ~pening and which are opened and clo~ed by synchronized c~ms. ~ecause the 6e~ting faces Qf the exhaust valves in internal co~u~tion engines are subjected to extremely high temper~ture they tend to burn, ox~dize ~r pr~v~de a ~ource of pre~gnitlon. Pre-ignition is frequently a ~ource of damag~ng engine k~ck.

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Accordingly, it is neces ary to cool the ~alve, limit operating temperature and/or maintain a xeducing a~mosphere during combustion. In a conventional engine this is ~ccompli~hed ~y using an excess of fuel, i.e. a rich mixture, over that necessary to 6upport the combustion process. This excess fuel i~ utillzed as a coolant for the exhaust valve ~s well as ~n6uring that there is no free oxygen ~t the end of the combustion process, which could oxidize the valve~. Because excess fuel i~ ~upplied to the cylinders, all the fuel is not completely combusted and unburned hydrocarbons from the uncombusted fuel are exhausted through the exhaust valves and the exhaust manifold sy~tem rather than ~ontributing to the output power. Because of this, the exhaust gas from the internal combustion engine pollutes the atmosphere excessively.
The use of the crank ~haft in a conventional internal combustion engine causes a kinematic limitation to the motion of the piston. That is, the translation of the reciprocating motion of the piston to rotary motion by means of a crank causes the piston to reciprocate up and down in the cylinder in the characteristic crank-slider motion, which i6 a higher order, non-sinusoidal motion. ~his characteri~tir crank slider motion cannot be conveniently altered and i~ ~ymmetric for each stroke, ~ecause it is fixed by the geometry of a crank/connecting rod assembly. The crank-slider motion of the piston in a conventional internal combustion engine i6 disadvant~gous for several reason~, including: 1) crank-slider motisn qener~tes higher inertial ~tresses than does pure sinusoidal motion, 2) crank-~lider ~otion results in increased time at or near top dead center (nTDC~), increasing the l~kelihood of pre-igniti~n, 33 ~ncreased dwell time recults in increased heat los~ to the engine bo~h before ~nd ~fter firing, ~nd 4) the torque arm ~ust after firing is ~mall, under utilizin~ the high X~.3C)~3L~9 i gas pressures ~nd 5) the torque ~rm near the end of the the ~troke when pres~ure i~ low, ~.eO near bot~om dead center ~nBDC~) is too 6mall for ef~ective eapture of the motiYe ~orce ~n thi6 gas. Furthermore, khe crank-slider motion ~oes not closely match the heat and pressure çonditions 3S ~ fun~tion of time that ~re created in the combustion chamber during the operation of the en~ine.
. In ~park ignition engines the longer the time period that the air-fuel mixture i8 compre~sed the greater li~elihood there i~ of pre-ignition. Bec~use the upward rise of the piston in a conventional engine i~ relatively 810w near ~DC, the ~ompressed air~fuel mixture i~ at or near its maximum compr~ssion during a relatively long period of time prior to top dead center. For this rea~on~ relatively low ~ompression ratios and/or high octane fuels are re~uired to prevent pre-ignition.
Immediately after passing top dead center and beginning its downward expansion stroke, ~he piston in a crank-type engine is also mo~ing relatively ~lowly.
In both ~park-ignition engines and compressi~n-ignition (i.e. Diesel) engines, the relatively ~low motion of the piston near top dead center causes excessive heat los~ because of the relatively long length o~ time that the hot combustion gases are in contact with the head and cylinder walls. Finally, the crank ~lider motion of the piston near the end of its stroke, that is near bottom dead ~enter, where the pr~ssures are the lowest, makes it difficult to effectively utilize the aYailable motive force in he ga~es, due to the pres~ures ~n~lved coupled with the 6hor effective arm of the cr2nk at thi~ position. ~hus, in conventional engines, the exhaust valve begins to open a signific~nt number of degrees before bottom dead centex, re6ulting ln a ~i~nificant l~fi of available energy of the ~ombu~ted gasesP

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Furthermore, in a crank-type engine, the intake ~troke of the piston in a four troke en~ine is inherently the 6ame length a~ the expan6ion ~troke.
Becau~e of the increase ln temperature and pre~ ure ~aused by combustion, ~t the bottom of the expanslon ~troke (even if the exhau~t valve were not to be opened until bottom dead center), the ~ombu6ted gases will still be at a higher prefi~ure than ~mbien Thus, ~ignificant loss in av~ ble moti~e fDrce in the combusted gases occurs when the exhaust valve opens and exhausts the higher than amhient pressure gas to ambient pressure. Various mecha~isms combined with the crank/connecting rod ~y~tem ~ave been proposed to try to capture more of thiC available work through more c~mplete expansion, but have not proven successful due to their cost and mechanical complexity. For example, the A~kinson mechani~m provides a cranktconnecting rod system with a longer expansion stroke than inta~e ~troke, but at qreatly increased mechanical complexity.
MorPover, the octane quality of commercially available fuels, which aff~cts the permissible compression ratio, varies considerably. Making provision for variable compxession ratio in the cylinders would allow the maximum permisEible compression ratio for a given ~uel, ~nd hence highest efficiency for ~ qiven fuel. ~owever, efforts to make internal combustion engines with variable compression ratios have not proven very ~uccessful in practice due to mechanical complexity. Thus, conventional internal combustion engines have non-ad~ustable compression ratios and engine manufacturer~ mu~t design compression rat~o~ to accept the poorest available fuel~ This c~mpromise results ~n an engine having a lower compre~6ion ratio than the ~ptimum, and hence a lower efficiency than the optimum for an average ~uel.
Gasoline manufacturer~ ~ell W~uper~ octane yasoline, therefore co~ventional engine~ designed for poor ~uel ~3~9~

derive no benefit from u~ing the6e costly "~uper"
fuel~.
In an attempt to alleviate ~ome of the difficulties of the cran~-type $nternal combustion engine, various rotary ngine designs have been proposed where the engine ~lock housing the cylinder~
and pistons of the engine is directly coupled to the output shaft of the engine and the entire block, with the assembly of cylinders and pi~tons, rotates along with the output ~haft. In one ~uch rotary engine proposal, ~nitPd State6 Patent No~ ~023,536, each piston has ~ roller which rolls against the interior ~urface of a cam to translate the reciprocating motion o~ the piston to rotary motion of the engine block rotox, instead of by means of a crank and connecting rod as in a crank-type engine.
Although the use of a cam overcomes the inherent kinematic limitations of a crank mechanism, these rotary designs have not been entirely successful.
In such rotary engine designs the cam acts directly upon the roller which is directly conected to the piston. Since it is the tangential (i.e. side~
component of force from the cam surface which causes rotation of the engine block, and hence the useful power output, th~se forces can only be transmitted to the engine ~lock in these designs by means of ~ide forces on the piston against the cylinder walls. These side Porces and friction contribute to excessive wear on the piston and cylinder in these prior art designs.
Fuxther~ore, because the entire engine block and pist~ns rotate in a r~tary engine, cen~rifugal force tends to throw the piston outward against the cam. ~hese centrifugal forces ar~ very large in magnitude, tend to increase wear on the cam ~urface and cam roller in prior art rotary engine designs, t~ereby llmiting ~ngine speed~ adversely.

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In rotary engines, the engine block with the cylinder~ rotates within a housing. Because of thi~, cooling the cylinders has proven difficult in prior art designs, because delivering sufficient air ox water ~o a rotating assembly of cylinders presents mechanical and ~ealing difficulties.
These ~nd other problems have thu~ far prevented the the practical implementation of a rotary engine design.
Ob-ects of the Invention ~ .
Accordingly, it i~ ~n object of the present invention to provide an internal combustion engine utilizing a rotating engine block c~upled directly ~o the output shaft of the engine which overcomes the foregoing disadvantages.
It is a further object of the presen~
invention to provide a rotary internal ~mbustion engine of increased efficiency and exhibiting lower unburned hydrocarbon and NOx emissions than conventional internal combustion engines.
AnotS~er object of the present invention is to provide a rotary internal combustion engine which avoids problems of excessive side wear on the pistons.
Still another object of the present invention is to provide a rotary internal CQmbUstion engine which avoids problems of the cen~rifugal forces acting on the pistons to cause excessive ~orce and wear upon the cam track ~urface and cam ~ollower, and to provide a force tending to return the piston to TDC.
Yet another object of the present invention i~ to provide a r~tary internal combustion engine of the character described wherein increased efficiency is obtained from the power ~troke of each 9f the cylinders because of a unique des~gn of the etationary cam ~urface on which the connecting rods act.

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A 6till ~urther object of the present invention i6 to provide a rotary ~n~ernal combu6tion engine which has ~ ~apability of developing a power ~$roke during more than 110 of rotation of ~h~ output ~haft for each cylinder.
A further object of the present ~nvention is to provide an internal combustion engine havin~ a ~mooth power output and a low ~dle speed.
A still further object of the present invention is to provide a rotary internal co~bustion en~ine wherein provi5ion can ~e made to vary the compression ratio within the cylinders during operation to optimize performance.
Still another o~ject of the present invention is to provide an internal combustion engine having decreased emissions of hydrocarbon pollutants and oxides of nitrogen.
Yet another ob~ect of the present invention is to provide an rotary engine cooled ~y oil in a novel manner.
Yet another object of the present invention is to provide a rotary internal combustion engine wherein one or more of the pistons ~an be selectively locked or unlocked depending upon engine operating parameters to provide variable engine displacement and more efficient engine operation, Still another o~ject of the present invention is to provide an ideal power plant ~or a light propeller driven airplane.

In accordance with an embodiment of the present invention, a r~tary internal combustion engine ~5 provided which has ~ housing, a cam track internally disposed within the hou ing and adapted to receive a cam follower, and ~ rotatable engine block di~posed within the hous~ng and rotatable ~b~ut a central axis.
The block includes ~n ~xi~lly extending output 6haft 9~1.

~nd at least one radially arranged cylinder as~embly on the block. Each cylinder ~s~embly has a cylinder having a longitudinal axi~ extending generally radially outwardly from the rotat~onal axis of the block ~nd means defining ~n end wall on the cylinder. A pi~ton member is disposed within the cylinder and is adapted to reciprocate within the ~ylinder. ~he piston includes a head end which together with said cylinder ~nd its end wall defines a ~ombustion chamber. ~eans permitting periodic introduction of aix and fuel into the combustion chamber, means for causing combustion of a compressed mixture of air and f~el within the combustion chamber, and mean~ permitt~ng periodic exhaust of products of combustion of air and fuel from the combustion chamber are provided. The engine also includes means for imparting ~orces and motions of th~
piston within the cylinder ~o and from the cam track comprising linkage means and a cam follower operatively connected to the linkage means. The linka~e means comprises a connecting rod having a first end portion pivotally connected to the piston member, a second end portion and a rocker arm. The rocker arm has a first end portion pivotally mounted to a mounting point fixed with respect to the block and offset with respect to the longitudinal axis of ~ts associated cylinder, a 6econd end portion pivotally connected to the ~econd end portion of the connecting rod, and an ~rm portion connecting the first and second end portions of the rocker arm. The cam follower i adapted to ride along the ~am track 60 that the ~am follower for~es and motions ~re tra~smitted to and from the piston, through the linkage ~eans, to and from th2 cam track. The cam track includes at ~eact a fir~t ~egment and at le~st a ~econd segment thereof~ The firs~ seqment has a positive ~lope wherein the cam track segment has a generally ~n~rea~ing radial di6tance from the rotational ~xi~ of the engine bloc~ whereby as a piston 2~)~3~9~
_g_ moves outwar~ly in a cylinder on a power stroke while the cam follower i6 in radial regi~ter with the cam traGk ~egment, the reactive force of ~he respective cam follower ~hrough the linkage means against the cam txack se~ment acts in 8 direction tending ~o ~mpart rotation to the ~ngine block ln the direction of the positive slope of the cam tr~ck ~egment. The ~e~ond segment has a negative slope wherein the cam txack segment ha6 a generally decreasiny radial di~tance from the rotational axis of the engine block whereby as a cam follower rides along th~ negative 810pe of the cam track as said engine block rotates, the cam follower w~ll cause a geometrically defined mot~on of the linkage means to compel a radially inward motion of the respective piston in its respective cylinder.

These and other objects, features and advantages of the present invention will become apparent to those skilled in the art upon reading the following description in conjunction with the figures, wherein:
E~ig. 1 is a diagrammatic end view of a cutaway portion of a preferred embodiment of the rotary engine of the present invention, chowing one complete cylinder assembly and portions of two other cylinder assemblles in their respective relative positions on the engine block;
Fig. 2 is a diagrammatic side view of the rotary engine depict~d in Fig. 1, taken along the line 2-2 of Fig. 1, ~nd a diagrammati~ representation of the o~l cooling and lubricating 6ystem in accordance with a preferred embodiment of the present invention, Fig. 2A i~ an end view of ~he ~tatie 6eal plate of the rotary valve o a preferred embo~iment of the presen invention;
FigO 3 i8 a diagrammatic end view of ~nother embodiment of the engine o~ the pre~ent invention, ~3~

showing one embodiment of means for af~ecting the compr~sion of the engine ~nd a different embodLment of the linkage mean~;
Fig. 4 i~ a diagrammatlc ~ide ~iew, partly in ~ec ion, of the embodiment of the engine depicted in Fig. 3, taken along the line 4-4;
Fig. 5 i~ ~ diagrammatic sec~ional end view of still another embodiment of the pre~ent invention lncludiny a variation of the linkage means in accordance with the present invention, and 6howing means for ~electively preventing pistons from reciprocating;
Fig. 6 ~s a ~iagrammat~c ~ectional ~nd vi~w of a rotary engine in accord nce with the present invention, ~howing another embodiment of the means for varying the compression ratio, including an adjustable cam track segment;
Fig. 6A is an enlarged sectional view taken along the line 6A-6A of Fig, 6, showing the constxuction of one embodiment of the adjustable cam track segment;
Fig. 7 is a graph of piston motions as functions of rotor angle in accordance with different embodiments of the present invention, and of piston motion~ in a crank-type engine for compariss~ purposes;
Fig. 8 i~ a table of the values of piston motion used to generate Fig~ 75 and Fig. 9 is a diagrammatic representation of a cam pr~file in accordanc~ with a preferred embodiment o the present invention, with numbers on the periphery of the cam profile corre~ponding with the p~sition number~ on the table of Fig, 8.
Fig. 10 i~ a zide ~iew of a multibank emb~diment o~ the present invention, including two rotary engine~ connected together in ~eries.
Fig. 11 i~ ~ p~rtially cutaway view of a propell~r driven l~ght airplane including a two bank (33~
rotary eng~ne in ~ccordanc~ with and embodi~ent of the pre~ent invention.
Fig. 12 i~ a graph of engine torque divided by cylinder pres ure as a function of rotor angle for a rotary engine in ~ccordance with the present invention having ~ simple harmonic motion, and a graph of engine torque divided by cyl~nder pre~sure for an e~u~valent conventional crank ~ngine ~ a unction of one hal~ the crank angle.
Fig. 13 is a graph depicting piston accelleration for different cam profiles in an engine constructed in accordance with an embodiment of the present invention, with piston accellerations for a conventional crank shown for comparison.
Detailed Description With reference to the figures, and initially to Figs. 3 and 4 thereof, a rotary internal combustion engine 10 i~ accordance with one embodiment o~ the pre~ent invention is depicted~ Engine 10 i~ a four ~troke, spark ignition engine with a carburetor 11, intake pipe 12 leading ~o rotary valve assembly 189, and ~parX plug 115. A four stroke compression ignition (Diesel) cycle could al~o be employed, in which case carburetor ll and spark plug 115 would be replaced with fuel inje~tion directly into the ~ylinder. Two stroke spark ignition and compression ignition cycles could al~o be used.
Engine 10 includes a rotatable engine block 13 coupled to an output shaft 110 which extends axially from each end of the rotatable engine ~lock 13 to provi~e a means of translating the rotation of the engine block 13 into u~eful work. Output ~haft 110 is supported by inboard bearing 318 and outboard bearing 319 which extend axially ~rom housin~ 14, which contains ~ngine block 13 and permits its rotation~
Bearing 318 2nd 319 are preferably conventional journal bearings, but other bearings ~ch ~s ball or roller bearings could al~o be providedO In~tead ~f an output shaf~ 110, other mean~ ~uch ~s a gear drive, ~hain drive, ~ydraulic drive, directly coupled electroma~neti~ genexator or other means ~or capturing the u~eful work could al~o be provided. Furthermore, ~034~

the engine in accordance with the present invention can also operate whexe the engine block 13 i~ held ~tationary t and the housing 14 allowed to rotate. In this ca~e, the output shaft or other means would be connected to the hou~ing 14.
~ otatable engine block 13 includes four radially arranged oylinder assemblies 30! whlch ~re pxeferably, though not nsces~arily, identical. Only one of these cylinder as~emblies will be described in detail, and the same description would apply to the other threé cyli~der assemblies. It ~hould be recognized, howeYer, that the invention i5 not limited to ~oux cylinder as~emblies, or any particular number of cylinder assemblies.
Each of cylinder assemblies 30 includes a cylinder 31, within which a pi~ton 21, preferably made of low inertia material such as aluminum, is reciprocally and slidably dispo~ed. Piston 21 includes piston rings 91, preferably ~ade of cast iron or ~teel.
Each cylinder assembly 30 includes an end wall at its radially inwardmost point, which is preferably a c~linder head 70, and a port area 75.
Each of pistons 21 include a crown or piston head 101.
The space between piston head 101 and cylindex head 70, tog~ther with port opening 199, forms combustion chamber 71.
In order to introduce air and/or fuel into each of the combustion ohambers 71, a rotary valve assembly lB9 is included. This rotary va~ve assembly is best ~een in ~igs. 2 2A, 3 and 4, and i~ preferably axially mounted at one end of output shaft 110. Port opening 199 in eombu~tion chamber 71 fun~tions as both an intake and exhaust port, ~nd exposes the combustion chamber to the ~park plug or diesel in~ection. This opening or port 199 extends throu~h a rotating seal face 194, which i~ arranged to ~ealably face ~nd rotate again~t a ~tatic ~eal pl~e 190 (not vi~i~le on Fig.

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3). Static seal plate 190 ~s pref~rably ~ounted to housing 14 without output 6haft 110 extending centrally through it~ As ~hown in Fi~. 2A, static ~eal pl~te 190 includes an intake port 196, and exhaust port 195 and a blanked-off portlon conta~ning no opening 197.
In operation, as engine block 13 rot~te~
clockwi~e, port 199 will rotate ~nto xegister wi~h-exhaust port 195 during th portion o the cycle wherein exhaust gases are to be discha~ged from combustion chamber 71. After the pi~ton reaches the end of its exhaust ~troke, the engine block 13 a~d opening 199 in rotatin~ ~eal face 194 will rotate into regi~ter with ~ntake port 196 and will remain in register with this intake port during the entire intak~
troke. Following the intake stroke, as the engine block 13 continues to rotate, port 199 will mov2 into register with blanked off portion 197 of ~tatic seal plate 190 during the compression ~troke. At the comple~ion of the compression stroke, combustion will be initiated in the combustion chamber 71 by either compre~Rion-ignition, in a Diesel version, or initiation by means of a spark through port 199 in a ~park ignition version. As the engine block 13 continues to rotate, opening 199 will remain in register with blanked-off portion 197 of ~tatic ~eal plate 190 unt;1 th2 expansion stroke is substantially complete, at which point ~pening 199 rotates int~
regi ter with exhaust port 195 to commence the cycle again.
As best ~een ~n Fig. 2, the rear ~ace 191 of ~tatic seal plate 190 is open to an oil cond~it 309, which circulates oil ~djaeent rear ~ace ~91 ~nd to oil return line 400. Ga~kets 193 prevent leakage of this eooling ~1 into the intake and/or exhaust of the engine. Circulation of oil cools the ~tatl~ ~eal 199 dire~tly~ and the rotat~n~ ~eal ~ace 1~4 of rotary valve a~sembly 189 $ndirectly by ~ondu~ti~n. ~nstead ~103~

of oil, water or other fluid could be used. ~hus, the rotary valve ~8~embly 189 ~an be kept at a temperature below that ~t which excessive oxidation would sccur.
Furthermore~ the heated oil or fluid c~n be ~ed to provide pas~engex somfort heat. Because the temperature of the valve is low, it i~ not necessary to use excessive fuel during combustion to prevent oxidation of the valves, as i~ the ca e with conventional poppet valvesq This result~ in better fuel economy and lower emi~sion of hydrocarbons and carbon monoxide t which otherwise result from rich fuel mixtures of prior art engines, Furthermore, the engine of the pre~ent invention lends itself to greatly ~impli~ied ignition, and intake and exhaust manifold~. As ~hown in Figs. 3 and 4, the engine has a "~ingle point" intake 12 and a "6ingle point" exhaust pipe 75, and a single spark plug, even though the enqine has four cylinders. In a conventional four cylinder engine, ~omplex and heavy intake and exhaust manifolds would be required, as well as four spark plugs and associated distributor and wiring. The ~single point" lntake is of especially great advantage ~n Diesel ~mbodiments of the present invention. In a conventional engine, an injection pump i~ required for each cylinder. In small engines, thi~
multpoint fuel injection ~ystem can cost a~ much as the rest of the engine. In the present ~nvention, only a ~ingle injection pump would be required, regardless of the number of cylinders.
Returning now to Fig. 3, to transmit forces and mo~ion~ to ~nd ~rom the pi~ton into use~ul work (i.e. rotation of engine block 13 ~nd shaft llOl, a connecting rod 41 iB pivotally connected at ~t~ upper end to pi~ton 21 by means of wrist pin 81. At the opposite end of connec~ing rod 41~ ~ cam follower 51 is ro~atably mounted ~b~ut an ~xle 5S. In the embodiment shown, the cam ollower ~ preferably ~ rotatable wheel 20~3~1 to minimize wear and friction. ~owever, ~ sliding cam follower, rather than a rolli~g cam follower, may al~o be employed.
Connecting rod 41 ii~ linked by means o~ link arm or rock~r arm 170 At a pivot 174 on the connecting rod 41 between axle 55 and pivot 81. The oppo~ite end of rocker arm 170 i6 r4ekably pivoted about rocker ~rm pivot 173, which is mounted on mounting plate 175 which is a~fixed ko and rotates with engine block 13. Pivot 173 is offset with respect to the centerline of cylinder 31 and causes the connecting rod 41 ~nd cam follower 51 to move in a ki~ematically defined path as piston 21 reciprocates.
Cam follower 51 is adapted to follow and roll about the inside periphery of cam track 60 as engine block 13 rotates clockwise. Cam track 60 has a generally ellipsoid shape which i8 preferably generally anti-symmetrical across a 12:00/6:00 line. By ~anti-~ymmetrical" is meant that if one were to cut the cam track at the 12:00/6sOO line, and turn one side o~
the cam track over about approximately the 9 00/3:00 line, the reversed cam track would then be symmetrical across the 12:00/6:00 line. The reason for the anti-~ymmetry is the geometry of the connecting rod/linkage as~embly with the rocker arm ro~ker pivot on each cylinder being positioned leading the centerline o~ its respective cylinder (i.e. more clockwi~e than cylinder centerline). Thus, anti-6ymmetry of cam tra~k 60 eauses pi~tons opposing one another to have the same radial position and reciprocal ~peed at a given rotor angle ~but oppositely directed~, resulting in le~ dyn~miG unbalanGe of the engine due to reciprocating ~a~ses.
The roughly 12:00 po~ition o the track in Fig. 3 corresponds to top dead center of the ~ompression ~troke, the roughly 3:00 position correspo~ds to the bottoni dead center of the expansion ~)()3~

~troke, the roughly 6:00 position correspond~ top dead center of the exhaust ~troke, ~nd the roughly 9sO0 posi~ion corresponds to the bottom de~d center of the intake Rtroke. Thus, a 360 rotation of engine block 13 c~rre~ponds to R complete ~our ~troke cycle.
~ he cam track ~eqment between the 12:00 top dead center angular position and the 3:00 bottom dead center angular position has A generally positive slope ~o th~t the radial distance between a point on cam track 60 and the ~enter of rotation of engine block 13 generally, preferably continuo~ly, increases between these angular positions of the engine block.
Similarly, the c~m tra~k segment between the 3:00 bottom dead center angular position and the 6:00 top dead center position has a generally negative ~lope so that the radial distance between a point on cam track 60 and the center of rotation of engine block 13 generally, preferably continuously, decrea~es between these angular po~itions o~ the eng~ne block.
As shown in Figs 1, 2 and 3, an inner cam track 65 is also preferably provided ~ubstantially parallel with outer cam track ~0, ~nd radially inwaxdly of cam follower 51. The purpose of inner cam tra~k 65 to to ensure that cam follow 51 remain~ substantially ad3acent to cam track 6~, that ~ , that i8 does not go radially inward of cam track 60, parti~ularly during intake ~nd exhaust stro~es when there is relatively little pressure in combustion chamber 71 acting on piston 21. Particularly in embodiments ~f the present invention where rocker arm extension 171 (and 171') and counterweight 172 ~and 172~3 are used to counterbalance centrifugal ~orces in a ~anner to be further explained~
at low engine ~peeds it i5 possible for centrifual forces acting upon the pi~ton/connecting rod/cam follower a~sembly to be in~ufficent to o~ercome friction ~uring intake ~nd exhaust ~troke~. Inner cam track 65 provides ~ means ~or ~pplying a radially 2~3~

outward force on cam follower ~1 to avoid this.
In~tead of an inner cam track, other mean~ of ensuring ~hat cam follower 51 remain~ ~ub~tantially adjacent to cam tr~ck 60 may be provided, ~uch ~ a ~pring to urge cam fo~lower ~1 outwardly aganist cam trac~ 60, or a mechanical ~top or bumper t~ prevent m~vement of the pi~ton/connecting rod/linkage ~ fiembly ~eyond TDC.
As engin~ block 13 rotates~ cam fol$ower 51 traver~es cam track 60. As the radial distance between a poin~ on cam track 60 and the rotational axis of the engine block 13 increases and decreases, c2m follower Sl moves radially inwardly and outwardly to transmit forces and mot~ons to ~nd from the cam track to from piston 21 by means of the connecting rodJrocker arm linkage assembly. Where the ~lope of cam 60 is positive 3Or negative), there is a tanqential, or "sidet' component of force acting between cam follower 51 and cam track 60. It is this tanyential component of force which, of cour~e, causes rotation of engine block 13, and hence the power output o~ the engine.
Correspondingly, the oppositely directed tangential force causes the pi~ton to move radially inwardly during the exhaust and compressions ~trokes. Rocker arm 170 transmits a large proportion of the tangential component of force ~cting upon c~m follower 51 by cam track 60 to mounting plate 175. In this way, forces imparted by the cam track 60 in a direction tendin~ to rotate engine block 13 in either direction are not primarily transmitted by means of ~ide forces acting upon the pi~ton within its cylinder, as is the ~ase with the prior ~rt, but rather by ~eans ~f the external linkage arrange~ent. ~hus t ~ide forces which w4uld otherwise tend to prematurely cause wear on the pi~t~n are minimized. Furthermore; becau~e the rocker pivot 173 i~ ~t a radially farther pos~tlon than the average pi~ton position, ~ greater lever ~rm i~ 2va~1able for the tran~mi~sion o~ torgue.

~133~31 ~18-The increased torque ~apability of the engine of the present invention a~ compared to an equivalently sized crankshaft-type engine i~ depicted diagrammatically in Fig. 120 ~he engine~ are equivalent in the EenRe of having the ~ame piston area and ~troke.
The absissa of the graph of Fig. 12 is the c~m~rotor an~le of an engine in accordance the pre~ent invention, having pure harmonic piston motion and one half the crank angle for an equivalent ~ized crankshaft-type engine. This is done because one revolution of the rotor of the present invention is equivalent to two for the crankshaft of a ~onventional engine. As can be seen from ~he graph, calculated torque per unit piston force is significantly higher for the engine of the present invention than for the equi~alent conventional engine from 5 through 60 of rotor angle. Although the torque for the rotor of the present invention begins to drop sharply thereafter, dropping to less than the conventional engine, thi~ is approximately the point at which the exhaust port or valves open, t~ius relievin~ the cylinder of pressure in any event. Thus, during substantially the entire period of rotation when u~eful work can be extracted from the gas (i.e. prior to opening the exhaust valve or port), the torque output of the present invention is ~ub~tantially greater than that of a conventional engine, resulting in higher po~er output and efficiPncy.
Rocker arm 170 prefera~ly includes an extension lin~ 171 extending beyond pivot 173 and in~luding counter weight 172 ~t it~ extreme or free end. Extension link 171 an~ countex-weight 172 ~re weighted to substantially counterbalance oentrifugal forces .cting upon piston 21, connecting rod 41, cam follower Sl and link arm 170~ These forces tend to throw pi~ton 21 ~n~ ~hese parts radially outwardly ;~03~9~.

against the cam tr~ck ~urface 60, tending to increase wear on the cam track follower and cam track surface 60. Link exten~ion 171 and counter-weight 172 are ~rrangea o that link arm 171 and counter-weight 172 tend to move radially ~nwardly ~s piston 21 move~
outwardly, thus tending to sub~tantially countera~t the centrifugai forces. ~owevex, preferably the weight of the counterweight is ~uch that this does ~ot completely offset the centrifugal forces, ~o that the piston ~nd cam follower are urged into contact with the cam track surfaoe. In this way, excessive wear due to centrifugal forces acting upon the oam track follower 51 and cam track 60 are minlmized.
'rhe arrangement of link~ges with respect to connecting rod 41 as depicted in Fig. 3 is not the only arrangement that can be used to accomplish the purposes of the present invention. For example, in Fig. 1, another embodiment of the engine 10' is depicted. In thi~ embodiment link 170 is connected to connecting rod 41 at the radially extreme end of connecting rod 41 by means of pivot 174'' which ~s coaxial with axle 55 for cam follower 51. In another embodiment, engine 10" is depicted in Fig. 5. In this embodiment, cam followex 51 is connected to lin~ arm 170' at the apex of a "Vn-~haped bend in link arm 170', rather than being pivotally connected to connecting rod 41. In this embodiment, connecting rod 41 is relatively ~hort, and the radially extreme ~nd of connecting rod 41 is pivoted to link 170' by means of pivot 174'. Link 170' is pivotally mounted at pivot 173l, which is in turn mounted to mounting plate 175. In this embodiment, extension link 171' and count~r weight 172' are integral with one An~therO
Ca~ ~urface 60 i5 profiled 80 as to translate the reciprocating motion of piston 21 through the linkage ~ssembly into rstary motion of en~ine blo~k 13, and hence output 6haft 110. ~ecause the rotary engine ;~03~&g~.

of t~e present ~nv~ntion has no crank, the inheren~
kinematic limitations of the crank-slider motion ~f a piston with a crank ~rrangement are eliminated. ~hu~, the ~hape of cam ~ur~ace 60 c~n be tailored ~o ~ume whatever profile be~t ~uit the heat snd pre~ ure characterifitic~ of the combust~on proceqs and/or any other design parameter requir~d.
One embodiment of a c~m profile is depic ed in FigO 9~ As depicted therein, the cam profile is a ~ubstantially anti~ymmetrical ellipsoid. The profile of Fig, 9 has poi nt 1-72 indicated about it~
periphery.
Fig. 8 i~ ~ tabulation of the relatiYe piston radial reciprocal po~ition as a function of rotor angle (Col. 2) for a cam follower 51 having a radius Wr~ of 1.5 inches (~ol. 1). Each of the peripheral points 1-72 on Fig. 9 corresponds to a crank or rotor angle position as indicated in Col. 7 of Fig~ B, beginning at crank or rotor angle o~ 0 at position 1. Pure harmonic (i.e. sinusoidal) piston motion i5 tabulated in Col. 3, which is the piston motion generated by the cam profile of Fig. 9. A configuration where the expansion stroke continues during 110 of rotor rotation is tabulated in Col~ 4~ The calculated piston motion for a cor~esonding four ~troke cra~k type engine are tabulated in Col~ S for a true 720 cycle, and in Col. S for a two stroke crank type engine having a 360 cycle for compari~on.
The pure or ~imple harmonic configuration is preferable in high-speed rotary engine designs, becaus2 it results in lower inertial ~tresses on the piston caused by reciprocation o~ the piston than ~rank-slider motion.
For even lower inertial ~tresses 8 a cam profile gener~ting ~ubsta~tially con~tant pi~ton reeiprocating ~cceleration may be employ~d. In a constant acceleration configuation, the pi~ton 9~.
-21~
accelerat~s radi~lly to a point at a ~ubst~ntially constant po~itive rate. At that point, the direction of a~celeration reverses, and continues at a ~ub~tantially constant but negative rate of acceleration. Calculated inertial ~txesses on a pi~ton due to reciprocation for a constant acceleration configuration are depicted graphically in Fig. 13, along with calculated inertial 6tresses ~or ~imple harmonic and crank generation motion~ for compari~on.
For applications where smooth power output and high efficiency i~ desired, the configuration having an expansion str~ke of greater ~han 90, pre~erably 110, may ~e employed. The 110 al~o results ~akes possible a lower idle speed; because of the 20 overlap in power ~trokes for a f~ur ~ylinder~
four stroke design, thus resulting in lower ~uel consumption in 5top and go traffic where a significant amount of time is ~pent at idle.
Other cam profiles may be employed wherein the piston has a longer expansion stroke than intake ~troke. This allows the high pr2ssure combustion gases to expand to closer to ambient pressure before exhausting the gases, resulting ~n higher efficency and lower heat rejection, and thereby less fuel ~onsumption.
Another configuration is one where the piston moves very rapidly toward top dead center prior to the initiation of combustion to minimize the time for pre-ignition to occur. ~his allows higher compression ratios with lower quality fuels, resultin~ in higher efficiency and lower ~uel costs.
Still ~nother co~figuration i6 one where the pi~ton move~ very rapidly off top dead center ~ollowing *he ~nitiation of ~ombustion to minimize the time during w~ich hot product~ of co~bustion are ~n contact with relatively co~l ~yl$nder wall~, thus contributing ~o les6 heat los~ and higher ef~iciency. The r~pid 2~3~9~
~22-expansion causeq ~ rapid decrease in pre~sure ~nd temperature, which decreases the garnering of pollutants, ~uch ~s oxides of nitrogen, becauRe there is less ti~e at the high pressure and temperature at which oxides ~f nitrogen are formed.
The cam can also be configured to provide a full exhau~t stroke to maximum TDC ~nd ~ full intake ~troke from maximum TDC to BDC irrespective of the compression ratio to yield ~etter breathing and scavenging with~ut valve overlap. Valve overlap (i.e., where both the exhau~t and intake valves are openl can increase emissions~ .
~ hese various cam profiles can ~e combined together in compromise profiles, and a myriad o~ other ~am profiles can be adopted for other custom requirements.
Turning now to Figs. 1 and 2, a preferred embodiment of the rotary engine of the pre~ent invention incorporating a novel oil cooling and lubricating 6ystem i~ depicted. In this system, a sump 300 containing oil is preferably positioned di~ectly below housing 14. Oil from the 8ump 300 is withdrawn through suction line 301 into oil pump 302. This oil pump is driven by means of a gear ~et 315 driven by ~haft 110. Oil pumped from oil pump 02 i6 pumped into discharge line 307A ~nd through filter 305 to remove particulates. Oil after having passed through filter 305 is di~charged into di~charge line 306B and then through oil coolex 307, whi~h may be either air ~r water cooled. Since oil pump 302 only operat~s when shaft 110 is rotating, the oil coollng and lubricating system preferably ~ncludes an electric oil pump 303 for ~hut down cooling and lubricating, and for lubricating pri~r to E~art up of the enqine. Electric oil pump 303 also take~ intake from 8ump 300 through an intake line 301 and discharge~ through a check valve 304 into discharge line 307A, then through filter 305 and oil ;~:003~L93l cooler 307 in the ~ame manner ~8 ~or oil pumped from oil pump 302.
Instead of (or in addition to) positioning oil cooler 307 on discharge line 306B, an oil cooler 307' can be included on the oil return line ~00 just up stream of the B~mp 300 to cool the oil ~u~t before the oil enters oil ~ump 300.
Oil, after having been cooled ~y means of oil ~ooler 307, passes ~nto a ~tationary line 307C and ~nto rotating oil inlet 308 to the engine rotor. Because inlet 308 rotates with respect to oil di~charge line 307C, a rotating oil ~eal 310 i~ included to prevent leakage ~f oil.
A ~ide stream of oil is taken from discharge line 307C and into line 309 to cool the rear face 191 of static ~eal plate 190 in the manner previously described. Oil from passageway 309 passes adjacent xear face 191 to cool the static seal plate and is discharged into oil return line 4Q0.
Oil from passageway 308 passes into the head end 311 of cooling jacket 320. ~ead end 311 includes a plurality of generally radially inwardly orieAted walls or fins 313, which are ~ubstantially parallel to one anothex. Wal s or fins 313 are spaced apart from one another to form troughs 312 between ~ins 313. As the cylinder block 13 rota~es, centrifugal force acting upon ~he oil will tend to cause ~he oil to be retained within troughs 312. The rotation of the e~qine block will also ~ause a centrifugal force field ~o be placed upon oil contained within each of the troughs 312 thereby tending to inc~ease the natural ~onvective forces acting upon oil within each trough 9 becau~e oil within each trough tend~ to be heated at the radially inward ~b~ttom~ of the trough and tend to ~rise~ ~way from the rotational center to be replaced by cooler oi lo By ~natural convect~ve force" i~ meant the tendency of hot, les dense, ~luid to rise abvve and be ~33~

-2~-displaced by cosler, more dense, fluid under gxavit~tional or other acceleration forces due to the difference in their den6ities, as distinguish2d from convection due to pumping the fluid by mechanical means past the surface to be cooled. In the present ~nvention, centripital acceleration caused by rot~tion of the engine block 6ubstitutes for gravitational acceleration in the "natural" ~onvention; Thus, cooler oil will tend to be forced into the bottom of each trough 312 while hotter oil will tend to ~e displaced over the tops of walls 313 and radially outwardly~
After passing through the head end 311 of the oil cooling jacket oil exits at 314, ~nd into the oil jacket 320 around the cylinder 31D
This heated oil will continue to pass through oil cooling jacket 320 adjacent cylinder 31 to cool the cylinder until the oil reaches an oil hole 321. Oil hole 321 i8 oriented 50 as to spray the discharge oil onto the cam follower 51 to cool and lubricate the cam follower. Oil return lines 400 are included on the bottom of housing 14 to allow the spent oil to return to oil 8ump 3~.
In addition to passing into oil cooling jacket 320, a ~ide stream of oil from rotor inlet 308 passes into a lubricating line 317, and hen~e through inboard rotor bearing 318 and then into oil ~ooling jacket 320, and a side straam passes to outboard rotor bearing 319, then to the driving gear set 315 for oil punp 302; and then to oil return line 400 to be returned to puunp 303 to s:ool and lubricate these parts.
Be~au6e engine block 1 is rotating, centri~ugal force~ ~cting on the oil contained within oil cooling jacket 320 will tend t~ ~orce the oil radially outwardly. Because o:E this, ~ 6maller oil pump 302 $hen wsuld ~e nece sary in ~ conventional engine it~ required, resulting in greater net power output ~rom ~haft 110. In additiosl; because oil is ~3~

used for cooling, as well as for lubricating, no water jacket around the cylinder i~ r~quired. Furthermore, the engine block ~160 transfer~ heat to the houging indirectly by heating the air within the housing, which ~n turn transfers it~ heat to the hou~ing. This indirect cooling i~ a~si~ted by rotation of the engine bloc~ within the housing, which cau~es ~ovement and mixing of the air in the hou~ing7 The inner ~urface of pi~ton head lOl and wrist pin ~l are cooled and lubricated by me~ns of oil thrown off the ~urface of cam follower 51 a it rotates. Finally, another oil spray hole 322 i8 provided on the outside of oil ~oolin~ j~cket 320 directed to thP pivot 173 of rocker arm 170 to provide lubrication of thi pivot. In thi~ manner, a very ~imple and reliable oil cooling and lubricating system which eliminates the need to use direct air or water cooling of the cylinders i~ provided. In addition to simplifying the construction, the use of oil cooling in accordance with the present invention allows the engine to run hotter, resultiny in higher e~ficiency.
In order to make most effective use of available fuels, the engine in accordance with the present lnvention preferably includes means for varying the compression ratio in ~ach cylinder ~sembly 30 while the engine is oper~ting. In ~ccordance with one embodiment of the present invention, depiet~d in Fig5.
6 and 6A as engine 10''~, compression can be varied while the engine i~ operating by mean~ of a compression control ~ystem 120. Compression control ~ystem 120 includes ~ knock ~enser 125~ which is preferably a piezoelectrie crystal. ~nock sen~er 125 ~e~ct~ the commencement of engine knock in the cylindex a~mblies 30. Signal~ from knock ~enser 125 ~re ~ed into an amplifier and control unit 130. Amplifier ~nd control unit 130 control ~he power input to a servomotor 135 to cau~e the ~ervomotor to rotate in one direction, 2~ 4931 tending to decrease compres~ion when engine knock i~
detected, ~nd to rotate in the oppo~ite direction to increase compression when engine knock iB not ~etected.
Servomotox 135 ha~ an output gear 140 which drives a reduction gear 145. Reduc~on gear 1~5 ~n turn drives a r~mp drive worm gear 150. Worm gear 150, in turn, rotates ramp drive threads 155l cau~ing drive element 153 to rotate axially thereby rotating acme threads 156 in and out. This ¢auses ramp drive rod 153 to either extend or retract, depenaing o~ the rotational directivn of ~ervomotor 135. ~amp drive rod 158 is connected to a movable cam track ~egment 159, which i~ positioned in an opening 157 ~n cam rack 60.
Of cour~e, other means of moving the cam track ~egment 159, ~uch as a hydraulic ~ylinder can be used, and there i~ no intention of limi~ing the invention to the exemplary en~odiment ~hown.
Movable ~am track 6egment 159 i8 comprised of a leading ramp 161 (and 161'~ and a trailing ramp 162 interdigitatably connected to one another by means of center joint pivot 166 having pivot head 167 and 167'.
Center joint pivot 1~6 is ~uitably connected to trailing edge 162, and extends through a slot 165 (and 165') in leading ramp 161. Trailing ramp 162 is pivotably mounted by means of pivot 164, and leading ramp 161 is pivotably mounted about pivot 163. As ramp drive rod 158 moves in and out in response to th~
motion of ~ervomotor 135, leading ramp 161 and trailing ra~p 162 will be pivotably moved in response thereto from radially further position~ to radially closer position%O Accordingly, as cam follower 151 rotates about cam track 60, when ~t reaches leading r~mp 161, it will be compelled to ride along leading ramp 161 until it re~che~ trailing ramp 162 and will ride ~long trailing ramp 162 until it reaches the continuati~n of ~am track 60. Thus, the path of cam follower 51 c~n be altered by moving leading ramp 161 and ~raili~g ramp ~ ~ O 3 ~ 9~..

16~ rad~ally inwardly or outwardly, either manually or automatically depending upon engine load or other engine parameters. For example, engine parameter~ such as engine temperature 9 exhaust temperature, ~nt~e air temperature, engine ~peed c~uld be fed into a fiuitably programmed ~icroprocessor to effect the control function. ~hu~, the highest compression po~ible, without engine knoc~, that is po~sible for ~ given fuel and engine load can be accomplished, re~ulting in increased engine efficiency~ Furthermore, the compression can be xeduced priox ko ~tarting the engine ~nd ~ept low until just after the engine 8tart5 to decrease the power required to crank the engine. Also, the compression can be lowered, manually or automatically, at idle. This reduces torque variation and t~ereby reduces the stable idle ~peed and fuel consumption at idle.
The compres~ion ratio in the engine the present invention can be varied as much as desired, but a particularly desirable range is from a low o~ 7:1 to 17:1. This range allows use of a wide variety of ~uels in a ~paxk ignition engine previously believed to be impossible. For example, it i8 ~elieved that even jet fuel can be carbureted and used succes~fully in an engine of the pre~ent invention, when the compre~ion s lowered to about 7:1. When higher octane ~uel is available, the compression ratio can be raised to allow higher efi~iency commensurate with the quality ~f the ~uel.
An alternate embodiment of the rotary engine o the present invention having means for varying the compression r~tio durin~ operation i~ ~epicted in Figs.
3 and 4. As depicted therein, the xo~ary eng~ne 10 includes driving gear 200 which i8 mounted to output ~haft 110. Driving gear 201 drlves ~ first idler gear 201, which, in turn, drives a 6econd ldler ge~r 202.
Idler gear 202 drives ~ driven gear 203 which i~

20~3~

connected to a compres~or cam ~04. Thus, as the rotatable engine block 13 rotates, compres or cam 204 will be rotated a corresponding number of degree~ by gears 200, 201~ 202 and 203.
Compressor cam 204 ln~ludes four lobe6, ea~h having a peak 206 and a notch 205 on the trailing side of the cam. A~ cam 244 rotates, it acts upon a drlven roller 207 whi~h i5 mounted ~o a movable cam track segment 20g by means of roller ~x12 208. Movable cAm track ~egment 209 is pivotably attached by means of pivot 210 to housing 14.
In oper~tion, movable cam rack ~e~ment 209 is in the radially outward po~ition, i.e~ with it8 leading edge substantially flush with the remainder of cam track ~urface 60. As engine block 13 rotates into position, and cam follower 51 rotates ~ufficiently so that :It i5 entirely upon the leading portion of the movable cam track ~egment 209, cam compressor 204 rotates correspondingly to a position where peak 206 aots upon driven roller 207 to cause movable cam track segment 209 to pivot radially inwardly, thereby driving cam follower 51 and hence pi5ton 21 into a position of higher compxession. This compre~sion is effected relatively quickly because o~ the cam action of ~am compressor 204. Becau~e pre-ignition i~
time-dependent, that i~ the ga~ter the compression the less likely pre-ignition ~s to occur with the ~ame compression ratio, the rapid compre~sion imparted by cam 204 minimizes the propensity for pre-igni~ion even at high compression ratios. Therefore, ~u~h higher compYession ratios, in the range of 18:1, can be used resulting in higher efficiency then is pos ible in engines of the prior art with relatively ~low compre~sion. In thi~ ~mbodiment, inner cam tr~ck 65 has an lndentation 66 near 12:00 top de~d center.
Indentation permit~ movable cam track ~egment 209 to move cam follvwer 51 radially inwardly without ~20~)349~

interference with inner cam track 65 at that point.
Because the region ~round 12:00 top dead center i~
always under relatively high pre sure (due to comprefision and c~mbustion) cam follower 51 will alway~
be finmly held ~gainst outer cam tr~ck 60 at thi8 position 9 lrrespective oP the lack of an inn~r cam track at this po~ition.
As cam 204 continues to rotate, driven roller 207 will fall lnto ~otch 205 causing the cam track ~egment 209 to rapidly return to a relatively flush position with the remainder of cam trac~ 60. This quickly reduces pressure and temperature of the combustion gases, re~ulting in higher ~fficency and lowex emi~sio~ of nitrous oxides. Thus, as cam follower 51 con~inues past the cam track ~egmen~ 209, when it reaches cam track 60, mov~ble cam trask segment 209 will be relatively flush with cam track 60 to allow the cam track roller 51 to continue unimpeded, and ready for another cycle with the next piston assembly.
Turning now to Fig. 5, an embodiment of the present invention utilizing a device for selectively locking a particular piston and linkaye assembly so that it does not recipxocate as the engine block 13 rotates i6 depicted. This loc~ing device includes a plunger lock 801 fixedly mount~d to cylinder 31.
Plunger lock i~ pre~erably a solenoid but could be a hydrauli~ cylinder. Plunger lock 801 includes a centrally disposed plunger pin 802. Rocker arm 170 includes a mating hole 803 which i~ adapted to receive plunger pin 8020 When rocker arm 170 is in the appropriate position, i.e. with the piston ~ubstan~ially at the top dead center of it~ ~tr~ke~
plunger lock 801 can be s~lectiYely energized t~ drive plunger pin 802 into mating hole 803. Once engaged ~n mating hole 803, rocker arm 170 will be loGked and piston 21 will not be ~ble ~o recipr~cate as engine block 13 rotate~. 0~ cour~e7 in this embodiment, innex ~:0~3~g~

cam track 65 would not be used because ~t would interfere with the motion of cam ~ollower 51.
Furthermore, thi~ ~tructuxe en~bles the engine of the present invention to continue to run e~en if one or more pistons ~eize~ By Yelectively di~engaging p~tons from reciprocating~ only the number o p~ston~
necessary to 6upply the xequired load will be operating, which result~ in ~igher efficiency.
- Plunger lock 801 can be operated manually, or automatically in response to engine load or other engine parameters. When operatPd automatically, an engine ~ensor 804 is provided responsive to engine parameter~, ~uch as engine speed and throttle position.
When engine load i6 low, ~ontrol mean~ 805 ~an actuate plunger lock 801 at the point i~ the rotation of engine block 13 where mating hole 803 is aligned with plunger pin 802. ~hen engine load incxeases to the point that additional cylinders are required, control means B05 disengag0s plunger pin from mating hole B03 at the ~ame, approximately top dead centerl position o~ the pi~ton.
An e~gine in accordance with the present invention is an ideal power plant ~or propeller driven light airplanes. In light airplanes, the propeller ~peed generally does not exceed about 2500 revolutions per minute (~rpm~). Because 2500 rpm is a relatively low speed for conventional crank type engines, reduction gearing ~etween the engine and the propeller i~ frequently ~ecessary ~o that the engine can r~n ht a higher, more e~ficient ~peed. In a rotary engin in accordance with the ~resent invention, the ~haft ~peed i~ one half that of a crank-type enqine having ~he s~me displacement ~nd number of ~ylinder~. That ~8 o n powex ~tro~e occur~ for each cylinder of the rotary engine in accordance w~th n prefered four-~tr~ke embodiment o~
the pre ent inYention once every ~haft revolution, wherea~ in ~ crank-~ype four ~ro~e engine, a power 3~L9~
-31- , ~troke occurs every othex revolution. Thu~ the rotary engine of the pre~ent invention rotates slowly enough to be directly coupled to a light a~rplane propeller withou~ reduction gearing, while having the high efficency of an ~effective~ speed ~compared to -an equivalent cr~nk-type engine) of twice it~ ~ctual shaft ~peed.
~ eference ~ now made to Figure 10 ~howing an alternate embodLment of the pre~ent ~nY2ntion wherein two ~imilar engines lOA and lOB axe proviaed on the ~ame drive ~haft 901. In thi~ constru~ion each of the engine blocks 13 a~sociated with the re~pective engine is Goupled to drive shaft 901 by ~ree wheeling bearings in a hydraulically actuated ~lutch assembly 902. The engin~ block 13 of engin~ lOA and its output ~haft 903 are hollow to permit output ~haft 904 of engine lOB to pass therethrough to connect with hydraulic clutch 902.
Hydraulic clutch 902 i~ operable to ~electively couple eit~er or both of output shafts 903 and 904 to the drive shaft 901. When both engines are coupled; the output shafts of the engines preferably rotate in ~he same direction at the 6ame ~peed.
Engine lOB may ~lso include an input ~haft 905 and another hydraulic clutch 906. Input 8haft 905 can lead from another engine ~nd be connected to engines lOA and 109 by hydraulic clutch 906. Thus, as many engines as de~ired can be banked together in ~eries in this manner, the output ~haft of one engine extending through a hollow rotor and output ~haft of the next engine in the ~eries. ~hus, if ~ome of the engine~ were operating and he others were not, the o~her engines could remain idle on the output ~ha~t without creating ~ drag to the operation o~ t~ other engines~
The banked engine concept ~hown in Figure 13 may be utilized where the expected load to be driven will vary and at tim~ two engines may be ~eeded while 2~03~

at other time~ ~nly one engine will be sufficient to provi~e the power ~utput requirement nec~ssary. ~ence, during periods of h~gh torque load demand both engines wvuld be engaged on the drive ~haft ~nd, after high torque load demand6 have ~ubsided, one of the engine~
can be topped, the hydraulic clutch disengaged ~nd that engine remain 6tationary ~nd idle while other en~ine power~ the output ~haft.
To ~o ~o, clutch 902 can be di~engaged ~ngaged ~o that engine lOB is actuated only in high torque load demand ~ituations. Aftex a period of c~gine ~se, clutch 902 is placed in a state ~o th t engine lOB operate~ continuously while engine lOA
operates only intermittently. In this way engine wear is shared by the plurality of engines in th~ bank.
~hus, a~ter a period o continuous use, a particular engine i~ relegated to 6tandby use while another engine, which previously has operated only intermittently, is relegated ~o cont~nuous operation.
Where the banked engine concept of the present invention is used for automobile power plants the switching of the engine can be accomplished after fifty thousand miles of operation and in essence a relatively new engine will a~sume the major burden of power output requirement while the engine which has functioned continuously for the fifty thou~and miles is relegated to intermittent duty.
Engines in accordance with ~he present invention, and particularly mul~ibanked engines, are particularly well ~uited for driving light airplane propellers, because the ~extra~ engine provide~ an ~dditional marqin of 6afety in ca~e of ~ailure of one of the engine~. Fig~ 11 depict~ a light propeller driven airplane 907 including ~ two ~ank ~mbodiment o~
the pre~en~ invention. The ~irplane includes ~
fu~elage 908 ~nd a propeller 909 driven by propeller drive ~haft 901 extending ~rom two ~imilar rotary ~ ~ O 3 ~ 9~.

engines lOA and lOB connectablQ together in Geries .
The intake line 911 and exhaust line 912 to and from the ~tatic valve plates are conveniently positioned between the two engines lOA and lOB, resp~ct~Yely.
Each of engines lOA nnd lOB can be selectiYely ~oupled or decoupled from the propeller drive ~haft 901 by means of hydraulic clutch 902. In thi~ ~nner, the safety and power of two independent engines can be prov~ded, while retaining the simplicity and co~t ~avings of a ~ingle propeller design.
Although the invention haG been described in accordance with preferred embodiments, it will be ~een by those 6killed in the art that many modifications can be made within the spirit and scope of the pr~sent invention, and no intention i~ made to limit the ~cope of the present invention to any of these embodiments.
Rather, the scope of the pxesent inventi~n is to be measured by the appended claim~.

Claims (39)

1. A rotary internal combustion engine, said engine comprising;
a housing;
a cam track internally disposed within said housing and adapted to receive a cam follower;
an engine block disposed within said housing, said engine block and said housing being relatively rotatable with respect to each other about a central axis;
means connectable to an external drive member for translating said relative rotation of said engine block with respect to said housing into useful work;
at least one radially arranged cylinder assembly on said block, each cylinder assembly including a cylinder having a longitudinal axis extending generally radially outwardly from the rotational axis of said block, said cylinder including means defining an end wall, a piston member disposed within said cylinder and adapted to reciprocate within said cylinder;
a combustion chamber, means permitting periodic introduction of air and fuel into said combustion chamber, means for causing combustion of a compressed mixture of air and fuel within said combustion chamber, means permitting periodic exhaust of products of combustion of air and fuel from said combustion chamber, and means for imparting forces and motions of said piston within said cylinder to and from said cam track, said means comprising linkage means and a cam follower operatively connected to said linkage means, said linkage means comprising a connecting rod having a first end portion pivotally connected to said piston member and a second end portion; a rocker arm having a first end portion pivotally mounted to a mounting point fixed with respect to said block and offset with respect to the longitudinal axis of its associated cylinder, a second end portion pivotally connected to said second end portion of said connecting rod, and an arm portion connecting said first and second end portions of said rocker arm; said cam follower being adapted to ride along said cam track so that said cam follower forces and motions are transmitted to and from said piston through said linkage means to and from said cam track;
wherein said cam track includes at least a first segment and at least a second segment thereof, said first segment having a generally positive slope wherein said segment has a generally increasing radial distance from the rotational axis of said engine block whereby as a piston moves outwardly in a cylinder on a power stroke while the cam follower is in radial register with said cam track segment, the reactive force of the respective cam follower through said linkage means against the cam track segment acts in a direction tending to impart rotation to said engine block in the direction of the positive slope of said cam track segment, said second segment having a generally negative slope wherein said segment has a generally decreasing radial distance from the rotational axis of said engine block whereby as a cam follower rides along said negative slope of said cam track as said engine block rotates, said cam follower will cause a geometrically defined motion of said linkage means to compel a radially inward motion of the respective piston in its respective cylinder.

2. The engine as defined in claim 1, wherein each respective cam follower is operatively connected to its respective linkage means by mean of an axle mounted on the second end portion of its respective connecting rod.

3. The engine as defined in claim 2, wherein said axle is substantially coaxial with the pivotal connection between the second end portion of the respective connecting rod and the second end portion of the respective rocker arm.

4. The engine as defined in claim 2, wherein the pivotal connection of said second end portion of the respective connecting rod and the second end portion of the respective rocker arm is between said cam follower axle and said pivotal connection of said first end portion of its respective connecting rod with its respective piston.

5. The engine as defined in claim 1, wherein each respective cam follower is operatively connected to its respective linkage means by means of an axle mounted on the arm portion of its respective rocker arm.

6. The engine as defined in claim 1, wherein said arm portion has a radially inwardly open "V" bend, and said can follower axle is located substantially at the apex of said "V" bend.

7. The engine as defined in claim 1, wherein said housing is stationary and said engine block rotates.

8. The engine as defined in claim 1, wherein said engine block is stationary and said housing rotates.

9. The engine as defined in claim 7, wherein said first end portion of each respective rocker arm further includes a counterweighted free end extending from said mounting point in a direction generally away from the longitudinal axis of said cylinder whereby centrifugal forces acting upon the respective piston, linkage means and cam follower will be counterbalanced to a substantial degree by centrifugal forces acting upon the free end of said respective rocker arm.

10. The engine as defined in claim 1, wherein said cam follower as a roller rollable along at least a portion of said cam track.

11. The engine as defined in claim 1, wherein said cam track is an outer cam track and wherein said device further includes an inner cam track spaced apart from and substantially parallel with said outer cam track and wherein said cam follower is adapted to closely fit between said outer track and said inner track.

12. The engine as defined in claim 1, wherein said end wall of each respective cylinder is a head fixed with respect to its respective cylinder.

13. The engine as defined in claim 1, wherein said said cam track has a shape such that each respective piston has a substantially longer power stroke than intake stroke.

14. The engine as defined in claim 1, wherein said said cam track has a shape such that each respective piston has a simple harmonic motion.

15. The engine as defined in claim 1, wherein said said cam track has a shape such that each respective piston has a power stroke greater than 90 degrees of relative rotation of said engine block.

16. The device as defined in claim 1, wherein said means for causing combustion of said compressed mixture of air and fuel within said combustion chamber is compression ignition.

17. The device as defined in claim 1, wherein said means for causing combustion of a compressed mixture of air and fuel within said combustion chamber is spark ignition.

18. The rotary internal combustion engine as defined in claim 17 wherein said engine operates on four stroke cycle.

19. The rotary internal combustion engine as defined in claim 1, wherein said engine operates on a two stroke cycle.

20. A rotary internal combustion engine comprising, a housing;
an engine block disposed within said housing, said engine block and said housing being rotatable with respect to each other about a central axis;
a cam track internally disposed within said housing and adapted to receive a cam follower;
at least one cylinder extending generally radially outwardly from said rotational axis of said block, each said cylinder having a head end radially nearest the rotational axis of said block;
a piston member disposed within each said cylinder and adapted to reciprocate within said cylinder;
a cam follower operatively connected to each said piston member and adapted to ride along said cam track to transmit forces and motions to and from said cam follower and said cam track;
means for circulating oil through said engine block and around said cylinders to cool said engine block and said cylinders, said circulating means comprising an oil sump stationary with respect to said housing, a stationary pump having an intake in said receptacle and a discharge, stationary conduit means having an inlet end connected to the discharge of said pump and an outlet end in the vicinity of the head end of each of said cylinders, an oil jacket around each of said cylinders, said oil jacket having an inlet end rotatably and sealably connected to the outlet end of said stationary conduit means and an open outlet end generally radially away from said inlet so that the rotation of said engine block wall impart centrifugal force to he oil in said oil jacket to assist in circulation and pumping of the oil, means within said housing for collecting heated oil which has exited said outlet ends, means for conducting said collected oil to said sump, and means for cooling said oil.

21. The engine as defined in claim 20, wherein the end of each of said oil jackets in the vicinity of the head of each respective cylinder includes a plurality of oil retaining walls defining troughs, each of said troughs being oriented with its bottom radially farther from the rotational axis of said block than its opening so that rotation of said engine block will impart a centrifugal force field to oil in each of said troughs tending to retain oil in said troughs, thereby centrifugally increasing natural convection on oil in said troughs which will cause hotter oil to tend to flow radially away from the bottom of said trough to be displaced by cooler oil under the influence of said centrifugal force.

22. A rotary internal combustion engine, said engine comprising:
a housing;
a cam track internally disposed within said housing and adapted to receive a cam follower;
an engine block disposed within said housing, said engine block and said housing being relatively rotatable with respect to each other about a central axis;
means connectable to an external drive member for translating said relative rotation of said engine block with respect to said housing into useful work;
at least one radially arranged cylinder assembly on said block, each said cylinder assembly including a cylinder having a longitudinal axis extending generally radially outwardly from the rotational axis of said block, said cylinder including means defining an end wall, a piston member disposed within said cylinder and adapted to reciprocate within said cylinder, a combustion chamber, means permitting periodic introduction of air and fuel into said combustion chamber, means for causing combustion of a compressed mixture of air and fuel within said combustion chamber, means permitting periodic exhaust of products of combustion of air and fuel from said combustion chamber, and a cam follower adapted to ride along said cam track so as to impart forces and motions to and from said piston and said cam track;
wherein said cam track includes at least a first segment and at least a second segment thereof, said first segment having a generally positive slope wherein said segment has a generally increasing radial distance from the rotational axis of said engine block whereby as a piston moves outwardly in a cylinder on a power stroke while the cam follower is in radial register with said cam track segment, the reactive force of the respective cam follower acts in a direction tending to impart rotation to said engine block in the direction of the positive slope of said cam track segment, said second segment having a generally negative slope wherein said segment has a generally decreasing radial distance from the rotational axis of said engine block whereby as a cam follower rides along said negative slope of said cam track as said engine block rotates; said cam follower will cause a radially inward motion of the respective piston in its respective cylinder; and means for varying the compression ratio of each of said cylinders during operation of said engine.

23. The engine as defined in claim 22, wherein said compression ratio control means includes a cam track segment which is adjustably movable in a generally radial direction to vary the radial distance between said adjustably movable cam track segment and the rotational axis of said engine block thereby to adjustably alter the path of said cam follower in a radial direction in the region of said adjustably movable cam track segment and, means for moving said movable cam track segment from a first position of lesser compression to a second position corresponding to the desired degree of compression.

24. The engine as defined in claim 23, wherein said means for moving said movable cam track segment from a first postion to a second position operates to move the cam track segment while a particular cam follower is riding along said movable cam track segment as said engine block rotates and further includes means for returning said cam track segment to said first position prior to the arrival of the next cam follower as it rotates toward the cam track segment.

25. The engine as defined in claim 22, further comprising means for automatically controlling said compression ratio control means, said means including means for detecting the presence of engine knock and means responsive to said detection means for decreasing compression ratio where engine knock is detected and for increasing compression ratio when engine knock is not detected.

26. The engine as defined in claim 22 wherein said means for varying the compression ratio of each of said cylinders during operation of said engine is operative to reduce said compression ratio at idle.

27. The engine as defined in claim 22 wherein said means for varying the compression ratio of each of said cylinders during operation of said engine is also operative to reduce said compression ratio prior to starting said engine.

28. A rotary internal combustion engine, said engine comprising:
a housing;
a cam track internally disposed within said housing and adapted to receive a cam follower;
an engine block disposed within said housing, said engine block and said housing being relatively rotatable with respect to each other about a central axis;
means connectable to an external drive member for translating said relative rotation of said engine block with respect to said housing into useful work;
at least two radially arranged cylinder assemblies on said block, each of said cylinder assemblies including a cylinder having a longitudinal axis extending generally radially outwardly from the rotational axis of said block, said cylinder including means defining an end wall, a piston member disposed within said cylinder and adapted to reciprocate within said cylinder, a combustion chamber, means permitting periodic introduction of air and fuel into said combustion chamber, means for causing combustion of a compressed mixture of air and fuel within said combustion chamber, means permitting periodic exhaust of products of combustion of air and fuel from said combustion chamber, and a cam follower adapted to ride along said cam track so as to impart forces and motions to and from said piston and said cam track;
wherein said cam track includes at least a first segment and at least a second segment thereof, said first segment having a generally positive slope wherein said segment has a generally increasing radial distance from the rotational axis of said engine block whereby as a piston moves outwardly in a cylinder on a power stroke while the cam follower is in radial register with said cam track segment, the reactive force of the respective cam follower acts in a direction tending to impart rotation to said engine block in the direction of he positive slope of said cam track segment, said second segment having a generally negative slope wherein said segment has a generally decreasing radial distance from the rotational axis of said engine block whereby as a cam follower rides along said negative slope of said cam track as said engine block rotates, said cam follower will cause a radially inward motion of the respective piston in its respective cylinder; and means for selectively preventing and permitting reciprocating motion of a selected piston in its respective cylinder, said means being operable during operation of said engine.

29. The engine as defined in claim 28, wherein said selectable means is a solenoid powered locking device.

30. The device as defined in claim 28, wherein said selectable means is a hydraulically powered locking device.

31. The device as defined in claim 28, wherein said selectable means is a mechanical locking device.

32. The device as defined in claim 28, wherein said selectable means further includes automatic control means responsive to engine operation parameters.

33. A rotary internal combustion engine, said engine comprising:
a housing, a cam track internally disposed within said housing and adapted to receive a cam follower;

a first valve plate on said housing, said valve plate including a front face, a rear face and at least an exhaust opening therethrough, and ~ portion containing no openings;
means for circulating a fluid adjacent said rear face of said first valve plate to cool said first valve plate;
an engine block disposed within said housing, said engine block and said housing being relatively rotatable with respect to each other about a central axis;
means connectable to an external drive member for translating said relative rotation of said engine block with respect to said housing into useful work;
at least one radially arranged cylinder assembly on said block, each said cylinder assembly including a cylinder having a longitudinal axis extending generally radially outwardly from the rotational axis of said block, said cylinder including means defining an end wall, a piston member disposed within said cylinder and adapted to reciprocate within said cylinder, a combustion chamber, port means relatively rotatable with respect to said first valve means permitting periodic exhaust of products of combustion of air and fuel from said combustion chamber, said means including an opening in said combustion chamber sealably facing said first valve plate so that as said engine block rotates, said opening will be rotated into communication with the corresponding exhaust opening in said first valve face at the appropriate portions of the engine cycle, and will be closed off at other appropriate portions of the engine cycle, means for causing combustion of a compressed mixture of sir and fuel within said combustion chamber, and a cam follower adapted to ride along said cam track so as to impart forces and motions to and from said piston and said cam track;
wherein said cam track includes at least a first segment and a second segment thereof, said first segment having a positive slope wherein said cam track segment has a continuously increasing radial distance from the rotational axis of said engine block whereby as a piston moves outwardly in a cylinder on a power stroke while the cam follower is in radial register with said cam track segment the reactive force of the respective cam follower against the cam track segment acts in a direction tending to impart rotation to said engine block in the direction of the positive slope of said cam track segment, and whereby as a cam follower rides along said negative slope of said cam track as said engine block rotates, said cam follower will cause a radially inward motion of the respective piston in its respective cylinder.

34. The engine as defined in claim 33, wherein said first valve plate further includes an intake opening therethrough and said port means on each respective cylinder assembly further includes means permitting periodic intake of an intake charge into said combustion chamber, said means including an opening in said combustion chamber sealably facing said first valve plate so that as said engine block and said housing rotate with respect to each other, said opening will be relatively rotated into communication with the corresponding intake opening in said stationary valve face at the appropriate portion of the engine cycle.

35. The engine as defined in claim 34, wherein said intake charge is a mixture of air and fuel.

36. The engine as defined in claim 34, wherein said intake charge is air.

37. A light airplane comprising a propeller and a rotary internal combustion engine operatively connected to said propeller to drive said propeller, said rotary engine comprising a housing;
a cam track internally disposed within said housing and adapted to receive a cam follower;
an engine block disposed within said housing, said engine block and said housing being relatively rotatable with respect to each other about a central axis;
means connectable to an external drive member for translating said relative rotation of said engine block with respect to said housing into rotation of said propeller;
at least one radially arranged cylinder assembly on said block, each cylinder assembly including a cylinder having a longitudinal axis extending generally radially outwardly from the rotational axis of said block, said cylinder including means defining an end wall, piston member disposed within said cylinder and adapted to reciprocate within said cylinder;
a combustion chamber, means permitting periodic introduction of air and fuel into said combustion chamber, means for causing combustion of a compressed mixture of air and fuel within said combustion chamber, means permitting periodic exhaust of products of combustion of air and fuel from said combustion chamber, and means for imparting forces and potions of said piston within said cylinder to and from aid cam track, said means comprising a cam follower operatively connected to piston, said cam follower being adapted to ride along said cam track so that said cam follower forces and motions are transmitted to and from said piston to and from said cam track;
wherein said cam track includes at least a first segment and at least a second segment thereof, said first segment having a generally positive slop wherein said segment has a generally increasing radial distance from the rotational axis of said engine block whereby as a piston moves outwardly in a cylinder on a power stroke while the cam follower is in radial register with said cam track segment, the reactive force of the respective cam follower against the cam track segment acts in a direction tending to impart rotation to said engine block in the direction of the positive slope of said cam track segment, said second segment having a generally negative slope wherein said segment has a generally decreasing radial distance from the rotational axis of said engine block whereby as a cam follower rides along said negative slope of said cam track as said engine block rotates, said cam follower will compel a radially inward motion of the respective piston in its respective cylinder.

38. A multibank power plant comprising at least a first and a second rotary internal combustion engine connectable together in series, each of said engines comprising:
a housing;
a cam track internally disposed within said housing and adapted to receive a cam follower;
an engine block disposed within said housing and rotatable about a central axis;
an output shaft extending axially from each said engine block, each said output shaft being coaxial with the other;

means for coupling said output shafts together so that said output shafts rotate together in the same direction at the same speed;
at least one radially arranged cylinder assembly on each said block, each cylinder assembly including a cylinder having a longitudinal axis extending generally radially outwardly from the rotational axis of said block, said cylinder including means defining an end wall, a piston member disposed within said cylinder and adapted to reciprocate within said cylinder;
a combustion chamber, means for causing combustion of a compressed mixture of air and fuel within said combustion chamber, means permitting periodic exhaust of products of combustion of air and fuel from said combustion chamber, and means for imparting forces and motions of said piston within said cylinder to and from said cam track, said means comprising a cam follower operatively connected to said piston;
wherein said cam track includes at least a first segment and at least a second segment thereof, said first segment having a generally increasing radial distance from the rotational axis of said engine block whereby as a piston moves outwardly in a cylinder on a power stroke while the cam follower is in radial register with said cam track segment, the reactive force of the respective cam follower against the cam track segment acts in a direction tending to impart rotation to said engine block in the direction of the positive slope of said cam track segment, said second segment having a generally negative slope wherein said segment has a generally decreasing radial distance from the rotational axis of said engine block whereby as a cam follower rides along said negative slope of said cam track as said engine block rotates, said cam follower will compel a radially inward motion of the respective piston in its respective cylinder.

39. The engine as defined in Claim 1, wherein said said cam track has a shape such that each respective piston has substantially positive and negative constant acceleration.