EP0142559A4

EP0142559A4 - Internal combustion engine.

Info

Publication number: EP0142559A4
Application number: EP19840902269
Authority: EP
Inventors: Marius A Paul
Original assignee: Individual
Current assignee: PAUL Marius A
Priority date: 1983-05-20
Filing date: 1984-05-17
Publication date: 1985-09-26
Also published as: DK25685A; AU3012684A; JPS60501370A; BR8406910A; EP0142559A1; DK25685D0; WO1984004779A1

Abstract

An internal combustion engine which is combined with a thermal cycle of the Rankine type in which water is heated to steam and injected into the engine along with the fuel for increasing the engine output. Increased power can be provided with a turbine compressor (16) receiving the exhaust from the engine and compressing the air intake to the engine. An additional fuel burner (22) may be provided to drive the turbine to provide still further increased and immediate power. The engine may be run either as a two stroke or four stroke engine. A single valve (7) may be used to communicate the engine cylinder with the air intake and exhaust when used in conjunction with a rotating valve (8) which selectively communicates the single valve with the air inlet or outlet. A two cycle engine having a precombustion chamber (35) has an opening which receives a piston profile (38) for providing increased performance.

Description

INTERNAL COMBUSTION ENGINE BACKGROUND OF THE INVENTION

The efficiency of today's reciprocating internal combustion engine is approximately 30% with respect to the conversion of the potential energy of the fuels into mechanical work. The balance of approximately 70% is lost in the cool¬ ing and exhaus systems. Generally, the recovering of the lost thermal energy is particularly complex and is justified only in the case of some high horsepower installations as encountered in power plants and aboard ships.

The present invention is directed to various improvements in internal combustion engines of either the two or four cycle type by maximizing the efficiency of the engines and increasing their work output.

SUMMARY

The present invention includes the follow¬ ing objects and advantages:

It associates and integrates, within the thermal cycle of the reciprocating internal-com¬ bustion engine, a thermal cycle of Rankine type, which develops itself simultaneously on the base of the residual energy of the thermal cycle of the reciprocating internal combustion engine.

- ' €?^*■-.- • O PI The thermal engine with internal combustion, the steam generator and the thermal engine with steam make up a unique machine and its separate thermal cycles (gases and steam) develop themselves in parallel and simultaneously, recuperatively, compensatorily and integratedly. The working agent is made up in its active phases (expansion and exhaust) of the burnt gases of the internal-com¬ bustion engine and of the superheated steam, generated by the integrated recuperative generator, which by mixing makes up a homogeneous working agent that acts on the piston and on a turbine (if used for a supercharged engine) .

The residual energy of the thermal cycle of the internal-combustion engine is transferred to the Rankine cycle of the integrated steam generator by a complex heat transfer (conduction, convection, radiation, contact and mixing) which takes place through the walls of the cylinders of the internal combustion engine, towards the cooling water that flows in a double concentric circuit, from outside to inside (radially) and that passes through the stages of preheating, vaporization and superheating, finally being injection, in the inner cylinder cooling jacket and from here in a chamber, concentric with the combustion chamber, where simultaneously takes

OMPI place the fuel combustion and the process of vaporization and the final superheating of the steam. The mixing of the two working agents and expansion in the cylinder of the thermal reciprocating engine, continued in the turbine of gases and steam, allows the complete utili¬ zation of the thermal energy (of the gases and of the steam) by expansion up to the energeti¬ cally runout thermal parameters, close to condensation state of the water steam, which state takes place in the noise-absorber with condenser, which finishes thus the route of the working fluid. The recovered water in the condenser (preferably at 80-90 degrees C.) is introduced again in the thermal cycle of the integrated thermal engine which an increased quantity by the condensated steams resulted from the hydrocarbon combustion; the ensemble of the integrated thermal cycles, which carries and recuperates the thermal energy generated in the engine cylinder from outside towards inside, automatically creates an adiabatiσ state of total elimination of the thermal loss and leads to the removal of the cooling system (excepting ^'that of the supercharging air) ;

The thermal engine, as a homogeneous unit, runs in a two or four stroke cycle;

The thermal four-stroke engine is provided with a unified system of gas exchange distribution by common valves of admission and exhaust and by ports at the cylinder base for scavenging and for additional air admission. The separation of the admission process from that of exhaust is carried out by a rotating distributor valve, concentric with the exhaust-admission valve, synchronized with stages of the four-stroke cycle;

The four-stroke thermal engine with the unified gas exchange distribution and thermal integrated cycles can be changed-over into a two- stroke cycle engine by a gear system with two ratios of transmission (n/1 and n/2) from the engine crankshaft to the distribution system, respectively, by the camshaft with axially dis¬ placement, provided with two cams for each cylin¬ der one for running in the four-stroke cycle and the second for running in the two-stroke cycle, the concentric rotary slide valve remaining blocked on the permanent exhaust position and the unique valve has the function of exhausting only. The change from the four-stroke cycle to the two-stroke cycle assures the engine a surplus of power of 75—80%, a-double possibility of power change and of carrying out a vast field of power and of operating conditions;

The two-stroke engine with scavenging by ports and with thermal integrated cycles is provided with admission-scavenging and exhaust ports at the

OMH base of the cylinder with a steam generating sleeve in the zone of the combustion chamber with a con¬ centric chamber, which assures the steam super¬ heating and their homogeneous mixing with the com¬ bustion gases, a simultaneous generation of working fluid (steam and gases) taking place even in the incipient stage of combustion, which develops it¬ self in the engine cylinder during the expansion stage and later in the turbine of exhausted gases, the engine combustion chamber being provided with upper ports, which make connection with the steam superheating concentric chamber and towards the interior of the cylinder is provided with a coni¬ cal nozzle, which is in conjunction with a disper¬ sive counterprofάle secured to the piston;

The supercharging of the two and four-stroke engines and the final utilization of the gases energy is assured by a combined diesel and gas turbine provided with a hyperbar combustion chamber for heavy- duty regime;

The convertible engine, in four and two-stroke, with integrated thermal cycles, is made up of an out¬ ward block, provided with an external water system, centered on the jacket of the steam generator, in the engine cylinder, the interior having the outer side spiral grooves for water leading and heat-trans¬ ferring. The base of the cylinder having piston control ports for scavenging and supplementary admis¬ sion. In the central upper part of the cylinder is

* ΕE

OMPI located a unique valve centered in a rotative distributor valve, driven in a ratio n/2 by the crankshaft, supported by a radial axial bearing J and driven in rotation by a gear; the reciproca¬ ting motion of the valve is achieved by a cam¬ shaft which actuates a tappet by the agency of an adjusting plate; the springs and the axial bearing assure the closing of the kinematic chain of the distribution. Air is absorbed by the turbocompressor, which blows the compressed air towards an intermediary cooler, from where by some ports penetrates to the base of .the engine-cylinder, simultaneously reaching the central valve zone by a pipe and enters the engine cylinder in the period of time when the rotative distributor provides the admission period. The exhaust gases escape from the cylinder by the central valve and the rotative distributor being in its exhaust period and are led to the exhaust- gas turbine, from where they -enter the noise- absorber and condenser. In parallel with the main air-circuit, the engine is provided with a by¬ pass circuit, made up of a pipe, a butterfly valve an annexed combustion chamber and an additional pipe for burnt-gases. The water for cooling and generating the steam is stored up in a tank, from where it is drawn by a low-pressure pump and led to the upper part of the cylinder block by a water jacket to a water injection pump, into the steam generating chamber, from where it enters the combustion chamber by a circular groove which sur¬ rounds the seat of the unique valve. The piston is provided with a central combustion chamber. In the case of passing to the two-stroke cycle, the cam¬ shaft is driven into rotation with the ration n/1 (by a mechanism not represented in the figure) having an axial translatory motion in order to work with the cams specific for the two-stroke cycle, the rotative distributor valve being simul¬ taneously blocked in the exhaust position.

The two-stroke engine with thermal inte¬ grated cycles is made up of a cylinder-block, provided with a cooling room, centered in the . jacket of the steam generator, the engine cylin¬ der is provided, on the lower part, with some admission and scavenging ports and some exhausting ports, and on the central upper part with a concentric chamber, which provides the steam super¬ heating by the contact with the walls of the com¬ bustion-chamber and with the burnt gases, which flow by the upper ducts and by the central nozzle, controlled by the piston profile. The air is absorbed by the turbo air-blower and sent to the air cooler, from where, by the scavenging ports, it enters the engine cylinder. At the start of the engine and at heaby-duty conditions the turbo air-blower is supplied with burnt gases delivered by the combustion chamber, which works in a by-pass circuit, controlled by a butterfly-valve, blowing the burnt gases by a pipe to the gas-turbine, from where the expanded gases mixed with the gases and

OMPI the steam exhausted from the cylinder by the exahusting ports, enter the condenser which recovers the water produced by the generator and by the combustion of the combustive hydro¬ carbons. The water is stored in a tank, from where is absorbed by a low-pressure pump and is introduced in the engine cooling jacket for preheating, finally being drawn by the water in¬ jection pump and injected in the steam generator,

Other and further objects, features and advantages will be apparent from the following description of presently preferred embodiments of the invention, given for the purpose of dis¬ closure, and taken in conjunction with the accompanying drawings.

_ O P B IEF DESCRIPTION OF THE DRAWINGS

Figure 1 is an energetical-functional diagram and cross setion through the four or two- stroke convertible engine with integrated thermal cycles.

Figure 2 is a functional diagram of the gas-exchange process for the four-stroke engine.

Figure 2.1 is an exhaust end-upper sca¬ venging (+a, -a) —admission beginning.

Figure 2.2 is admission by the unique valve and supplementary admission by the ports at the cylinder base.

Figure 2.3 is compression end and upper scavenging (+a, -a) ,

Figure 2.4 is exhaust by the unique valve and scavenging by the ports at the cylinder base.

Figure 2.5 is exahust by the unique valve.

Figure 3 are chrono-sections diagram of the gases-exchange in the four-stroke engine.

Figure 4 are entropical diagrams of the internal-combustion cycle and of the Rankine as¬ sociated and integrated cycle.

Figure 5 is an energetical-functional diagram and cross section through the two-stroke engine with distribution by ports, with integrated thermal cycle.

Figure 6 is a fuel injection diagram.

Figure 7 is a water injection diagram, and

Figure 8 is a diagram of the pressure variations in the engine.

^■ OMPI DESCRIPTION OF THE-PREFERRED EMBODIMENTS

Referring now to Figure 1, the convertible four and two-stroke engine with integrated thermal cycles, is shown running in the four-stroke mode and is made up of an outer block 1, provided with an outer water-space 2, centered on the steam- generator jacket 3, with the working cylinder in the interior having spiral grooves 4 on the outer part forming a passageway for water and for heat-transferring. At the base of the cylinder are ports 5 for supplementary air admission and scavenging, controlled by the piston 6. A unique valve 7 is located in the central upper part of the cylinder, being centered in a rotative dis¬ tributor valve 8, driven in a ratio n/2 by the camshaft 80 and supported by a radial-axial bearing 9 and driven in rotation by a gear 10. The re¬ ciprocating motion of the valve is achieved by a camshaft 11, which actuates a tappet 12, by the agency of an adjusting plate 13. The springs 14 and the axial bearing 15 assure the closing of the kinematic chain of the distribution. Air is absorbed by the turbocompressor 16, which blows the compressed air towards an intermediary cooler 17, from where by the ports 5 enters the base of the engine cylinder, simultaneously reaching the zone of the central valve 7 by the pipe 18 and enters the engine cy¬ linder in the period of time when the rotator distributor 8 assures the admission period. The

OMPI exhaust gases escape from the cylinder by the central valve 7 and by the rotative distri¬ butor 8, when it is in the exhaust period, and are led to the exahust-gas turbine 16, from where they enter the noise-absorber 19 which includes a condenser. In parallel with the main air- circuit, the engine is provided with a by-pass circuit made up of a pipe 20, a butterfly valve 21, an annexed combustion chamber 22 and an additional pipe 23 for the burnt-gases. The water for cooling and generating the steam is stored in the tank 24, from where it is drawn by a low-pressure pump 25 and led to the upper part of the cylinder block 1, by a water jacket 2 to a water injection pump 26, into the steam gene¬ rating chamber 4, from where it enters the com¬ bustion chamber by a circular groove 27, which surrounds the unique valve seat 7. The piston 6 is provided with a central combustion chamber 28.

The two-stroke engine with integrated thermal cycle, according to Figure 5, is made up of a cylinder-block 29, provided with a cooling room 30, centered in the jacket of the steam- generator 31, which is provided at the lower part of the cylinder with some admission and scavenging ports 32 and some exhausting ports 33. On the central upper part is provided a concentric chamber 34, which assures the steam superheating by the contact with the walls of the combustion-chamber 35 and with the burnt gases, which flow by the upper ducts 36 and by the central nozzle 37, controlled by the profile 38 of the piston 39. The air being absorbed by the turbo air-compressor 40 is sent to the air-cooler 41, from where it enters into the engine-cylinder by the scavenging ports 32. The turbo air-blower 40 is supplied, at the engine start and at heavy-duty conditions, with burnt gas delivered by the combustion- chamber 42, which works in a by-pass circuit, controlled by a butterfly-valve 43, blowing the burnt gases by the pipe 44 to the inlet of the gas-turbine 40, from where the expanded gases, mixed with the gases and the steam exhausted from the cylinder by the exahusting ports 33, enter the condenser 45, which recovers the water produced by the generator and by the combustion of the combustible hydrocarbons. The water is stored in the tank 46, from where is drawn by a low-pressure pump 47 and it is introduced for preheating in the engine cooling jacket, finally being drawn by the water injection pump 48 and injected in the generator for high-pressure steam.

The process and the two and four-stroke convertible engine with integrated thermal cycles operates according to the invention as follows:

The turbine driven air compressor 16, electrically driven, begins to deliver compressed- air to the combustion chamber 22, which starts and accelerates the turbo air-blower at the normal speed delivering the supercharging air.

O PI The engine, being started, can run from the beginning in the maximal working regime.

The fuel injection, according to Figure 6 takes place with an advance of a versus the top dead center, the water injection is produced by the high pressure pump 26, which injects portions of water, preheated in the jacket of the steam generator 3 with an angular delay indicated in Figure 7, and with pressure higher than those existent in the combustion chamber, preferably about 221 bars critical pressure value and tem¬ peratures of 647 K=374 C. The water cirtical temperature is achieved and corresponds to the temperature of air compressing end or to a usual temperature reached by gases during the initial period of the combustion. The steam generation at cirtical parameters leads to maximal efficiency from the point of view of the consumption of mechanical work and of use of the potential energy of the superheated steam, during the combustion, at values determined by the temperature peak of the combustion. The expansion of the homogeneous mixture of gases and steam in the en¬ gine cylinder 3 up to temperatures of 300 to 350 C=573 to 623 K, continued in the turbine of exhausted gases up to temperarues of approximately 120 C, allows the complete utilization of the potential energy of the working agent.

The mixture of gases and steam enters the condenser 19 with the noise-absorber, which

_OMPI lowers the temperature below the condensation point (about 90-95 C) , temperature with which the water is introduced again in the circuit of cooling, preheating, evaporation, super¬ heating and condensation.

The functional succession of the strokes in the four-stroke cycle with unified distribu¬ tion by the single valve 7 and the ports 5 take place as shown in Figures 2.1, 2.2, 2.3, 2.4, 2.5.

Position 2.1 - Exahust cut-off when the central valve 7 is completely open, the piston 6 is in the top dead center and the rotative distributor valve 8 is in the position indicated by Figure 2.1.1, and there takes place the superior scavenging of the burnt-gases with the fresh compressed-air originating in the pipe 18.

Position 2.2 - The air admission takes place by cylinder connection with the pipe 18 while the piston 6 is moving down, the central valve 7 is open and the rotative distributor is in position 2.2.1. The piston 6 opens the air prots 5, by which a supplementary air-quantity is delivered. The admission sections totals can be either equal or surpass to the piston surface, leading to a filling of maximum-maximorum order.

Position 2.3 - The air-compression takes place after closing by the piston of the air ports 5 at the cylinder base, while the piston 6 is going

O P up, the central valve 7 is closed and the rota¬ tive distributor 8 is in position 2.3.1. The fuel injection, combustion and injection of water-steam at critical parameters takes place at the end of the compression.

Position 2.4 - The expansion takes place, while the piston 6 is moving down, up to the moment E when the unique valve 7 is open and produces the free exhaust of the burnt gases; in the moment the piston opens the scavenging ports 5, by which penetrates the scavenging air, which pushes the burnt-gases out of the cylinder. In this moment, the rotative distributor 8 is in position 2.4.1 and makes the connection of the cylinder with the exhaust manifold for gases and steam towards the turbine 16.

Position 2.5 - The piston 6 goes up during the exhaust-phase and removes the steam-gases mix¬ ture towards turbine 16. During this phase the unique valve 7 is completely open and the rotative distributor 8 is in position 2.5.1, assuring con¬ nection between the cylinder and the exhaust- manifold.

In Figure 3, there are indicated the schematical variations of the chronosections, in connection with Figure 2, 2.1, 2.2, 2.3, 2.4, 2.5 the following conclusions being drawn: During the preliminary exhaust phase 2.4 the burnt gases are strongly pushed from the cylinder with air of forced scavenging through the ports 5, assuring a perfect cleaning of the cyli-nder of consumed gases, the inner cooling of the whole piston surface, of the cylinder, of the cylinder-head and of the exhaust valve.

During the proper exhaust phase 2.5, the mixture of steam, gases and scavenging that entered by the ports 5 is exhausted by the pis¬ ton 6 as far as the top dead center.

During the upper scavenging phase 2.1, the piston 6 finished the complete gases-exhaust and the rotative distributor 8 assures an upper scavenging 2.1.1, which completes the perfect cleaning of the cylinder of useless gases (burnt gases and of expansion) .

During the admission phase 2.2, the air enters through the valve 7, the rotative dis¬ tributor 8 is in position 2.2.1, and through the ports 5, into the cylinder and completing the cylinder filling up.

The operation of the convertible engine in the two-stroke variant is carried out by changing the rotations ratio (from n/2 to n/1) between the crankshaft and the camshaft 11, which is shifted axially and actuates the cam 50 proper for the two-stroke cycle. In this variant the rotative distributor 8 is locked in the position-per¬ manent exhaust. The fuel injection system (not shown) , having the rotations synchronized with the camshaft automatically passes at the nes rotation-regime. Particularly, the speed- governor of the injection pump continues to be driven from the engine canshaft 80. In this function regime the valve 7 is the exhaust valve and the ports 5 carry out the scavenging and filling of the cylinder. The water injec¬ tion is synchronized with the fuel injection, and the adaptation at the new functional regime is automatic.

The operation of the two-stroke engine with distribution through ports with the inte¬ grated thermal cycles, according to my invention and to the Figure 5, takes place as follows:

The turbo-blower 40 is driven into rota¬ tion by an electrical starter and supplies air from the compressor end to the combustion chamber 42, which by combustion brings the turbo-blower 40 to the normal rotation rate, which allows the supplying of the air necessary for the two-stroke engine. Simultaneously, the engine is driven by an electrical starter, which releases the opera¬ tion in conditions of normal regime.

The water necessary for the steam generator is absorbed from the tank 46 by the circulating low-pressure pump 47 and is introduced through the outer preheating circulation in the jacket 30, from where it is taken over by the water injection high pressure pump 48 and is injected at the critical parameters (pressure= 220-240 bars, temperature-374° C.) in the jacket of the steam generator 31. This assures the water and steam transport in the upper central zone, in the concentric chamber 34, where the steam, super¬ heating at the combustion process parameters (2200° C to 2300° C. and 150 bars) takes place, thus making the thermal process very efficient. The expansion of the homogeneous mixture of steam and burnt gases up to the inlet parameters in the turbine 40 with 350° C. and the final expansion up to the temperature of about 120° C. renders profitable integrally the potential energy' of the working fluid. The mixture of gases and steam energetically exhausted is introduced in the condenser 45, which lowers the temperature below the condensing point (about 90-95° C), recovering the water, which is condensed and stored in the tank 46.

The advantages of the new process and of the engines operating with integrated thermal cycle are as follows:

It carries out maximum of energetical efficienty utilizing the whole potential energy, actually utilizable by a combustion process, which leads at the most reduced specific fuel consumption.

OMPI It assures the highest energetical con¬ centration possible to be carried out in thermo¬ dynamics by the possibility of the engines to run supercharged in stoichio etric regime.

It assures an integral adiabatic func¬ tioning regime by the complete utilization of the energy exhausted from the Diesel engine cycle at maximal efficiency of the energetical parameters.

It eliminates the necessity of the cooling systems massively simplifying the engine construc¬ tion.

It massively reduces the engines thermal and mechanical stresses and adequately extends their operating life.

The occurrence of the overcharged water steams in the moment of combustion leads to the integralpollution reduction of the noxious constituents of the burnt and exhausted gases and represents the radical solution of thepollution phenomenon at a level of maximal energetical efficiency.

The engines with integrated thermal cycles can be generally applicable without restrict¬ ing or limitative conditions. They massively

OMPΓ con ribute to reduce the world-wide energe¬ tical crisis.

The four-cycle engine can be used with or without the Rankine cycle and provide an improved engine by using a single valve 7 for admission and exhaust of gases which can therefore be made larger than conventional valves and which is used for scavenging and additional air emission. The rotating distributor valve 10 performs the separation of the admission pro¬ cess from that of the exhaust and is concentric with the exhaust-admission valve 7. The four¬ cycle engine can be quickly and easily changed over into a two-cycle engine and vice versa for changing the power output and availability of use in different applications. Both the two and four- stroke engine can be supercharged by use of the gas turbine compressor circuit and with the further use of a combustion chamber for heavy-duty and quick starting operations.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned as well as others inherent therein. While presently pre¬ ferred embodiments of the invention have been given for the purpose of disclosure, numerous changes in details of construction and arrange¬ ment of parts will be readily apparent to those skilled in the art and which are encompassed with¬ in the spirit of the invention and the scope of the appended claims.

Claims

AMENDED CLAIMS

[received by the International Bureau on 20 September 1984 (20.09.84); original claims 1 to 16 replaced by amended claims 1 to 34]

1. In an internal combustion engine having a cylinder and a piston reciprocally movable in the cylinder, an improvement comprising: cooling jacket means surrounding substantially the entire cylinder and defining a thin space. in which a film of cooling fluid can be heated by heat conducted outwardly through the cylinder, the thin space being in continuous communication with the working space within the cylinder; and injection means for injecting a prescibed amount of cooling fluid into the thin space defined by the cooling jacket means at a prescribed time during each complete cycle of the engine, such that the resulting cooling fluid film is heated to produce high pressure, superheated vapor for entry into the working space within the cylinder, and such that a Rankine cycle is thereby provided.

2. An improvement as defined in claim 1, wherein the thin space defined by the cooling jacket means is a narrow spiral passageway beginning near the lower end of the cylinder and ending near the upper end of the cylinder.

3. An improvement as defined in claim 2, wherein the narrow spiral passageway defined by the cooling jacket means is in continuous communication with the engine cylinder via a circular injection port adjacent to the upper end of the cylinder.

4. An improvement as defined in claim λ , wherein the cooling jacket means further includes means defining a cylindrical chamber surrounding the narrow spiral passageway for use in pre-heating the cooling fluid prior to injection into the spiral passageway by the injection means.

5. An improvement as defined in claim 1, wherein substantially all of the prescribed amount of cooling fluid injected by the injection means is thereafter heated and introduced into the cylinder working space as superheated vapor during a single cycle of the engine.

6. An improvement as defined in claim 5, wherein the cooling fluid injected into the thin space by the injection means is further heated by the compressed air and exhaust gases present in the cylinder working space and in the thin space, because of the continuous communication between the cylinder working space and the thin space.

7. An improvement as defined in claim 1, and further including means for recovering at least a portion of the cooling fluid from the exhaust gases and steam expelled from the engine during its exhaust cycle, the recovered cooling fluid being subsequently used by the injection means.

8. An improvement as defined in claim 1, wherein the thin space defined by the cooling jacket means surrounds a substantial portion of the engine cylinder's upper wall.

9. An improvement as defined in claim 8, wherein: the internal combustion engine further includes a precombustion chamber located immediately above the upper end of the cylinder; and the thin space defined by the cooling jacket means further surrounds the precombustion chamber.

10. An improvement as defined in claim ϊ, wherein the cooling fluid injected by the injection means absorbs substantially all of the heat conducted away from the cylinder working space, such that the internal combustion engine is an adiabatic system and is free of any additional means for dissipating heat conducted away from the cylinder working space.

11. An improvement as defined in claim 1, wherein the cooling fluid includes water.

12. A thermal engine comprising: an internal combustion apparatus including a cylinder, a piston reciprocally movable in the cylinder, intake means for introducing air into the cylinder at predetermined intervals, and exnaust means for removing combustion gases from the cylinder at predetermined intervals; , an external combustion apparatus including a combustion chamber, intake means for channeling air into the combustion chamber, and exhaust means for channeling combustion gases from the combustion chamber; compressor means for supplying air to both the intake means of the internal combustion apparatus and the intake means of the external combustion apparatus; valve means interposed between the compressor means and the intake means of the external combustion

OMPΓ ^" ^■ S

apparatus, for regulating the amount of air supplied thereto; and turbine means driven by the combustion gases removed from both the internal combustion apparatus and the external combustion apparatus; wherein the internal combustion apparatus and external combustion apparatus operate independently of each other.

13. A thermal engine as defined in claim 12, wherein: the internal combustion apparatus further includes vapor means for generating high pressure, superheated vapor and for entering it into the cylinder at predetermined intervals; the exhaust means of the internal combustion apparatus removes both combustion gases and vapor from the cylinder at the predetermined intervals, whereby the internal combustion engine further operates in a Rankine cycle; and the turbine means is further driven by the vapor removed from the internal combustion apparatus.

14. A thermal engine as defined in claim 13, and further including means for mixing together the combustion gases and vapor removed from the internal combustion engine with the combustion gases channeled from the external combustion engine, whereby the vapor is reheated prior to driving the turbine.

15. A thermal engine as defined in claim 13, wherein the vapor means of the internal combustion apparatus includes:

_O P! cooling jacket means surrounding substantially the entire cylinder and defining a thin space in which a film of cooling fluid can be heated by heat conducted outwardly through the cylinder; and injection means for injecting a prescribed amount of cooling fluid into the thin space defined by the cooling jacket means at a prescribed time during each complete cycle of the engine, such that the resulting cooling fluid film is heated to produce high pressure, superheated vapor for injection into the working space of the cylinder.

16. A thermal engine as defined in claim 15, wherein the internal combustion apparatus is an adiabatic system and is free of any means other than the vapor means for dissipating heat conducted away from the cylinder working space.

17. A thermal engine as defined in claim 12, and further including means for cooling the portion of the compressed air supplied by the compressor to the intake means of the internal combustion engine.

18. In an internal combustion engine having a cylinder, a piston movable in the cylinder, fuel injection, and an air intake and gas outlet, an improvement comprising: a central valve longitudinally movable relative to the cylinder for opening and closing the cylinder to the air intake and gas outlet; and a rotary valve coaxiaily positioned with the central valve with means for selectively connecting the central valve to the air intake and the gas outlet, the 5 0

means including drive means for continuously rotating the rotary valve synchronously with reciprocation of the central valve.

19. An internal combustion engine as defined in 18, wherein the central valve comprises a common reciprocating valve of admission and exhaust and the rotary valve comprises a distributor valve with rotary slide means for selective separation of admission and exhaust on synchronous rotation with the stages of a four-stroke cycle.

20. An internal combustion engine as defined in claim 19 comprising further, ports at the cylinder base in periodic piston-controlled communication with the air intake for admission of a supplemental air quantity to aid scavenging and combustion.

21. An internal combustion engine as defined in claim 20, wherein the admission area of the ports in combination with the admission area of che central valve when open, at least equals the cross sectional area of the cylinder.

22. An internal combustion engine as defined in claim 18, wherein said engine includes a crankshaft and a camshaft, • the rotary valve being operably connected to the crankshaft and the central valve being operably connected to the camshaft, the camshaft being driven in rotation with a ratio of n/2 with respect to the crankshaft for operation of che engine in a four-stroke cycle, the rotary valve alternately providing admission and exhaust on openings of the central valve.

3 ϊ

23. An internal combustion engine as defined in claim 22 comprising further, air admission ports at the cylinder base in periodic, piston-controlled communication with the air intake.

24. An internal combustion engine as defined in claim 23 with transmission means for operating the engine in a two-stroke cycle, wherein the camshaft is driven in rotation with a ratio of n/1 with respect to the crankshaft, the rotary valve providing exhaust on each opening of the central valve.

25. An internal combustion engine as defined in claim 24, wherein the camshaft has a first select cam for a four-stroke cycle and a second select cam for a two-stroke cycle, the camshaft being shiftable axially for select engagement of either cam on selected four-stroke or two-stroke operation.

26. In an internal combustion engine having a cylinder, a piston movable in the cylinder, fuel injection, and an air intake and gas outlet, an improvement of conversion means for four to two-stroke engine operation comprising: valve means at the top of the .cylinder for communcation of the cylinder selectively with the air intake and the gas outlet; air admission ports at the cylinder base in periodic piston-controlled communication with the air intake; first valve drive means tor selectively operating the valve means synchronous with the stages of a four-stroke cycle; second valve drive means for selectively operating the valve means synchronous with the stages of a two-stroke cycle, with the valve means at the top of the cylinder blocked from communication with the air intake; and means for selectively switching the first and second valve drive means for selective operation of the engine in a four-stroke cycle or a two-stroke cycle.

27. In an internal combustion engine having a cylinder defining a main working space and a piston reciprocally movable within the main working space, an improvement comprising: means defining a precombustion chamber concentric with and immediately above the main working space defined by the cylinder; means defining a central, concentric opening between the precombustion chamber and the main working space, for channeling the flow of gases therebetween; and means defining a concentric channel surrounding the walls of the precombustion chamber and interconnecting the precombustion cnamber with the main working space, for further channeling the flow of gases therebetween.

28.. An improvemenc as defined in claim 27, wherein the means defining a concentric channel includes a plurality of ports interconnecting the concentric channel with the upper end of the precombustion chamber.

29. An improvement as defined in claim 27, wherein the concentric channel has a substantially uniform cross-section. \ 30. An improvement as defined in claim 27, wherein the wall separating the concentric channel from the precombustion chamber has a thickness substantially the same as the thickness of the concentric channel.

31. An improvement as defined in claim 27, wherein: the central, concentric opening has a tapered periphery; and the top side of the piston includes a tapered profile that is conformably engagable with the tapered periphery of the central, concentric opening, to vary the effective area of the opening.

32. An improvement as defined in claim 31, wherein the profile on the top side of the piston substantially closes the central, concentric opening when the piston is located at its uppermost position.

33. An improvement as defined in claim 27, wherein: the internal combustion engine is a diesel engine and is devoid of any intake or exhaust valve adjacent to the precombustion chamber; and the internal combustion engine further includes both intake ports and exhaust ports near the lower end of the cylinder and further includes means for injecting fuel into the precombustion chamber.

34. An improvement as defined in claim 27, wherein the internal combustion engine further includes means for injecting high pressure, superheated vapor into the concentric channel surrounding the precombustion

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chamber at a prescribed time during each complete cycle of the engine, to cool the wall separating the concentric channel from the precombustion chamber.

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