BACKGROUND OF THE INVENTION One of the most important, but not always in common resolved problems regarding the engine construction, is to improve the efficiency of the engine to use completely the heat delivered to the cylinders and to achieve better equalizing and steadiness improving the reliability and the operation of the engine. There are cam internal combustion engines and Stirling-cycle machines, all comprising at least one axial cylinder, all cylinders located parallel to and equidistantly from the main shaft of the engine. Each cylinder is provided with a mobile piston, the rod of which is connected to cam surface of a drum by cam follower with possibility to move through the cam. The cam profile is constructed as a curve circumscribed according to a determined function. The cam is connected to the main shaft. Besides, the engine comprises means for delivering and/or removing the working substance, both connected with the combustion chambers of the engine. The cam engines, besides the simple construction, which can be executed symmetric to the axis, permit according to the function for movement of the cam followers through the drum cam simultaneously to influence in great extent over the thermodynamic cycle of the engine and to be achieved total equilibration regarding the inert forces.

There are cam engines of Stirling cycle with a swash plate /US 5343704/ or cam executed according to harmonic function MO 82/04101 of Moscripl. Here the process proceeds according to the thermodynamic cycles for this type of engines which results in reduction of the efficiency. Besides it is impossible to regulate the operating duty according to loading and can not be achieved improved equilibration and steadiness of the engine.

The cam internal-combustion engines are more popular. For example, it is known from US 4492188 cam internal-combustion engine of Palmer with cam executed according to sinus function. This function permits achievement of better equilibration and steadiness of the engine, but insures the work regarding only some of the popular thermodynamic cycles for gasoline or diesel engine. The cycles do not permit better use of the supplied heat, therefore the thermodynamic and efficiency coefficients are low.

There are also known other cam internal-combustion engines with cam being for example saw line with rectilinear asymmetric parts in view /US 4553508, Stinebaugh/, or cam with dead points in each axial direction at different levels /US 5140953/. It is possible cam curve which /US 5218933/insures during compression to diminish sharply the velocity of the piston on ignition and after that to increase before reaching top dead center. All these curves by which the cams of known engines are constructed have some advantages, to improve the thermodynamics which results in increased efficiency factor and diminished emission of hazardous gases. From the other hand however, these curves do not permit the achievement of balance during work of the engine because of the appearance of non-balanced inert forces and moments. This enables lower reliability and wear resistance of the engines, especially when operating at more intensive duties and promotes increased level of noise.

There is also known a cam internal-combustion engine from US 4149498, comprising the above mentioned elements and parts, with cam having undulating configuration with rectilinear parts corresponding to top and bottom dead centers of the piston, which insures constant volume of the chambers during phases of combustion and free loss of combustion gases. The engine working with such cam has important advantages, its thermodynamic cycle reaches to the ideal approaches, but as the curve does not insure equal velocities and accelerations of the pistons during all phases it is again impossible to be achieved the balance of the engine. Besides, the processes of overlapping and refuelling which are not executed at constant volume, enable lower fresh working substance and increased quantity of burned combustion gases in the working volume of the cylinder resulting in lower efficiency factor of the engine. Besides, the hydraulic losses increase in the means, supplying the working cylinder with fresh working substance. This engine does not change the compression ratio at different load, which does not insure effective work of the engine at different operating duty. Besides, the construction of the engine is complicated and not reliable.

If we examine in more details US 4553508 we shall see that in one embodiment the cam curve for movement of the followers can be periodical, having symmetric rectilinear branches towards the middle of the period, connected smoothly to each other. It can be useful to realize only the known thermodynamic cycles, because all phases of the process operate by inconstant volume. Besides, on transition between every two branches of the cam will dynamic impacts appear which lower the reliability of the engine, because it is not secured constant contact in the movable connection between the followers and the working profile of the cam. On execution of the cam according to the preferred modification with asymmetric branches towards the middle of the period, it is not secured the balance of the engine during work, although the thermodynamics is improved. Besides the above mentioned elements and units, the engine comprises also other elements improving the work, as a mechanism to regulate the compression ratio, being force cylinder connected with the working cam drum and moving it through splined connection axially to change the working volume of the cylinders on different load. Besides there are means for guide the followers, which are a slide block supporting the piston rod and slipping over two parallel guiding rods each with round- cross section, these rods connected fixedly to the upper and lower of the engine case round the cam drum. This engine however besides disadvantages, coming from the curve of the working cam has complicated construction, comprising lots of elements which lower the reliability. It is not provided a mechanism to displace the fuel-air mixture distribution phases.

There are big losses from friction in the splined connection between the working shaft and the cam upon changing the compression ratio. The mechanism regulating the compression ratio enables the appearance of pulsation on movement of the cam through the working shaft, causing vibrations and noise with different amplitude and level for cold and warm engine.

SUMMARY OF THE INVENTION The main object of the invention is to provide a cam engine with the highest efficiency, which is more economical and environmentally save.

It is a further object of the present invention to provide an improved cam engine which is maximum balanced and reliable and having improved wear resistance of exploitation.

The level of noise and vibrations to be normal. The engine must operate without impacts.

It is another object of the present invention to provide an improved cam engine having better dynamic qualities.

It is another object of the present invention to provide an improved cam engine being effective at all operating duties, keeping optimal thermodynamic cycle, realizing the maximum possible efficiency for each operating duty of the engine.

It is another object of the present invention to provide an improved cam engine, which must be manufacturable for production and repair, with low specific amount of metal and low energy consumption for construction.

It is another object of the present invention to provide an improved cam engine, which should enable the building in different working machines.

The next object of the present invention is to provide an improved cam engine which permits the use of simple transmission and gives possibility for more functions.

It is another object of the present invention to provide an improved cam engine keeping the serviceability at higher working temperatures and temperature differences.

The above mentioned and other objects of the present invention have been achieved by a cam engine comprising working shaft and at least one axial cylinder, all cylinders located parallel to and equidistantly from the working shaft. Each cylinder has at least one piston with possibility of reciprocating movement in the cylinder, the said piston connected with a cam mechanism. The chambers of the cylinders can be connected with means for delivery and/or means for removal of the working substance. The cam mechanism comprises at least one cam drum connected coaxial with the working shaft and at least one cam follower with the possibility of reciprocating movement through guides. At least one of the followers is connected with a piston rod, forming a real piston cam follower. Each cam follower is in contact with the possibility of movement through at least one of the working profiles of the cam drum. Each profile of the cam is executed with undulating configuration according to a function, continuous until at least to its second derivative within the whole cam curve, so upon movement of the followers, their velocity and accelerations at the beginning and at the end of each ascending and descending sector from the period of the curve of the cam are with equal value, and the maximum and minimum values of the accelerations are located in one of the middle centers of each ascending and descending sector of the period. This way are eliminated the dynamic impacts of each follower upon transition from one stroke to another and are created conditions to receive lower velocities of their movement round their dead centers which improves the efficiency of the engine. Besides, on these conditions periodical functions for movements of the cam followers can be synthesized which enable equal conditions for the work of the engine notwithstanding its number of strokes and the kind of work of the followers of one-sided or two-sided action.

It is preferably the curve of the cam to be executed undulated and the accelerations of the followers equidistant from the beginning and/or the middle of each ascending or descending sector from the curve to be with equal value and opposite sign. This way is achieved the maximum possible balance of the engine, because the unbalanced inert forces are diminished to a greater extent, especially when the masses of the cam followers are equal.

It is preferably the curve of the cam to be executed undulated, so upon movement of the followers their velocities and accelerations at the beginning and at the end of each ascending and descending sector of the period to be equal to zero. It is preferably to be provided rectilinear sector for at least the one-side located convexities on the cam curve, so each piston to remain static upon movement in at least unilateral dead centers. This way the engine realizes thermodynamic cycle, which enables more rational use of the supplied heat for the cylinders and lower quantity of toxic gases. The result is higher efficiency factor of the engine, which is economical and save for the environment. Besides the hydraulic losses diminish. Besides, this engine permits to be maximum balanced when the cam followers are with equal masses, even number, at least four and located steadily round the axis of the cam.

This improves the wear resistance of the engine, facilitates the suspension and diminishes the noise level.

A mechanism changing the compression ratio and/or also a mechanism to control the fuel-air mixture distribution can be built in the engine, making it equally effective for each operating duty. It can be built also a mechanism, providing permanent contact between the followers and the curve of the cam, which facilitates the installation and eliminates the appearance of dynamic impacts.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal graphic representation of a section of four-stroke cam internal- combustion engine; Fig.2 and 3 show a function and its second derivative of movement of the followers with a flat portion in each top and bottom dead center.

Fig.4a and 4b show a graphic representation of the thermodynamic cycles corresponding to known four-stroke diesel engine and cam four-stroke diesel engine according to the invention; Fig.5 shows a view of a mechanism of cam engine with one real piston cam follower; Fig.6a and 6b are view and a cross section through the body of a cam follower and fig.6c is a view of a cage from the assembly of the cam follower and guide; Fig.7a-d are cross sections of different embodiments for assembly of the cam follower and guides; Fig.8 is a cam mechanism comprising two real piston followers and two simulating followers; Fig.9a-d are schemes showing different ways of location of the cam followers round the cam drum; Fig. 0, fig. 11 and fig. 12 show views of cam mechanisms with different orientation of the real piston followers; Fig. 13 a and fig. 1 3b show a function and its second derivative of movement of the cam followers with rectilinear horizontal sectors in each top and bottom dead center and with rectilinear sectors in the middle of all ascending and descending branches of the curve; Fig. 14 is graphic representation of the difference in the level in axial direction for two contact surfaces from the working profile of the cam; Fig. 15 is schematic representation of contact coupling between a cam follower and the groove of the cam in top dead center; Fig. 16a-c show different ways for elastic suspension of the contact element from the cam follower; Fig. 17 shows a follower, enabled to work with cam having working flange; Fig. 18 shows the coupling between component cam with groove and contact elements of the cam follower; Fig. 19 is longitudinal section of mechanism changing the compression ratio; Fig. 20a-d show different embodiments of the lifter of the mechanism from fig. 19; Fig.21a and 21b show cross sections of embodiments of the unit for axial displacement from the mechanism shown on fig. 19; Fig. 22a and 22b show embodiments ofthe splined unit for axial displacement; Fig.23 is longitudinal section of engine with two working cams and two-side located piston-cylindrical groups; Fig.24 and fig.25 are embodiments of mechanism insuring optimum tightening between the guides and the cam followers of the cam mechanism; Fig.26a-d show a regulator of centrifugal type for mechanism to control the fuel-air mixture distribution according to fig. 1, working with advance; Fig.27a-c show regulator of centrifugal type for mechanism regulating the fuel-air mixture distribution according to fig. 1, working with retardation; Fig. 28 is longitudinal section of mechanism controlling the fuel-air mixture distribution of toothed type; Fig. 29a-c show different embodiments of component cam block from the mechanism regulating the fuel-air mixture distribution according to fig.28; Fig. 30 is longitudinal section showing part ofthe cam engine with reversible block for turning the direction of the fuel-air mixture distributive mechanism and cam block for fuel- air mixture distribution of lever type; Fig. 3 la-c show different embodiments of component cam block of the fuel-air mixture distributive mechanism according to fig.30; Fig. 32 shows longitudinal section of the engine from fig.30 with cam block for fuel- air mixture distribution of rocker type; Fig. 33 is section of reversible block according to fig.30; Fig. 34 is section of reversible block with derivation of movement from the reversible gears; Fig. 35a and 35b are schematic upper and lateral representations of the reversible block from fig.34, joined with distributive cam shafts regulating the fuel-air mixture distribution of cylinders located in groups in direction of one of the engine's cross clearance; Fig. 36 and fig. 37 are longitudinal and cross sections oftwo-stroke cam engine; Fig. 38a and 38b show graphic representation of the thermodynamic cycles, corresponding to the known two-stroke engines and to a two-stroke cam engine according to the invention; Fig. 39 is longitudinal section of cam engine of Stirling type with two cams and opposite located cylinders for constant low and constant high temperature; Fig. 40 is cross section of cam engine of Stirling type with one cam and one-side located cylinders; Fig. 41a and 41b show a function and its second derivative of movement of the followers with flat portions in one-side located convexities of the cam curve from fig. 39 and fig. 40; Fig. 42a and 42b are schematic representations of dephasing and additional dephasing for the cams ofthe engine from fig. 39; Fig. 43 a-c are diagrams corresponding to the known thermodynamic cycles of engines Stirling type, of the cycle of the engine from fig. 39 with dephasing of the cams in angle and the cycle ofthe engine from fig. 39 with additional dephasing ofthe two cams.

DETAILED DESCRIPTION OF THE INVENTION Different engines can be realized according to the invention - internal-combustion four-stroke and two-stroke engines and external-combustion engines of Stirling type. The examples regarding the cam's curve will be given for internal-combustion four-stroke engines, but the analysis is valid also for two-stroke engines and the engines with Stirling cycle.

Fig. 1 shows one embodiment of four-stroke engine according to the invention. The engine comprises working shaft 1 and in this case more than one axial cylinders 2, located equidistant and steadily round the shaft 1. In each cylinder 2 with one-side or two-side operation, in this case with one-side operation, can be located depending on the operation at least one piston 3 with possibility for reciprocating movement. The pistons 3 of all cylinders 2 are joined with cam mechanism comprising a cam drum 4, connected with the shaft 1, this way is ensured possibility for mutual receipt and delivery of motions, forces and moments.

The cam mechanism further comprises cam followers 5 contacting the cam 4 and guides 6 to guide the followers 5.\The curve of the cam 4 has undulating configuration and ensures function for movement of the cam followers 5, which is continuous at least to its second derivative within the whole rotation interval from 0° to 3600 of the cam 4. On movement of the followers 5 the velocity and the acceleration at the beginning and at the end of each ascending and descending sector from the period of the curve of the cam 4 are with equal value and the maximum and minimum values of the accelerations are located in the middle centers of each ascending and descending sector. This way are equaled the conditions on which effects the thermodynamic cycle in engine with two-side cam followers and relatively low values are received for the velocity of the cam followers 5 round each dead position. This thermodynamic cycle is especially effective for engines working with fast combustible air-fuel mixtures. Besides, the conditions improve to achieve the balance of the engine. Fig. 2 shows a function for movement of the cam followers 5 corresponding to the curve of the cam 4 where is possible the velocities and the accelerations of the followers 5 at the beginning and at the end of each ascending and descending sector from the period of the curve to be equal to zero.

This way are achieved better conditions for effecting of the thermodynamic cycle with slower combustible fuels. It is shown that in each convexity from the curve can be provided rectilinear horizontal sector and on movement of each piston 3 to remain static in each top and/or bottom dead position. This insures improved conditions for operation of the thermodynamic cycle in all operating duties with the slowest combustible fuels. Besides, it insures constant volume of heat supplied to the combustion chamber and enough time for its assimilation, better ventilation of the working cylinders and charge with fresh working substance. The rectilinear horizontal sectors can be equal to each other which besides the improvements in the cycle, ensures the achievement of complete balance for the engine. When comparing fig. 4a and 4b show that with the cam engine according to the invention whose curve on the cam drum is realized according to the function on fig. 2 is increased in great extent the efficiency of four-stroke diesel engine /fig. 4b/ and is diminished the negative work for elimination of the gases in comparison with a conventional four-stroke diesel engine /fig.

4a/.

As example, satisfying the necessary conditions for the realization of the function for movement of the cam followers 5 from fig. 2 for the whole interval from 0° to 3600 of rotation of the cam 4 can be shown the following equality: # 1 # S((p)= H [ - sin(27t Y 27: Y where H - piston stroke; y - angle of rotation of the cam 4 where the piston 3 realizes its stroke; (p - angle of rotation of the cam 4.

In the shown example the pistons 3 execute four strokes for one turnover of the cam 4, and for the first interval (for realization of the first stroke, the function receives the following forms where: - angle of rotation of the cam 4 upon realization of one working stroke.

#- angle of rotation of the cam 4 where the piston 3 remains static. <BR> <BR> <BR> <BR> <P> 5 <BR> <BR> <BR> <BR> <BR> <BR> <BR> 0 # # # S 2 <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> 5 5 <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> # # 6 6 2 1 2 # # # S(#)=H[ sin (2# 2 2 Y 2# Y <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> 5 <BR> <BR> <BR> <BR> <BR> <BR> <BR> # # # S(#)= H, 2 for the second stroke, as follows: <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> 5 <BR> <BR> <BR> <BR> <BR> <BR> # # # + S(#)= H; 2 5 5 <BR> <BR> <BR> <BR> # - # - - 5 2 1 2 + # # # 2 S(#)= H-H[ - sin(2# 2 r 2# r <BR> <BR> <BR> <BR> <BR> #<BR> <BR> <BR> <BR> 2 - # # 2 S(#)=0, 2 for the third stroke, as follows: <BR> <BR> <BR> <BR> <BR> #<BR> <BR> <BR> <BR> 2 # # # 2 + S(#)=0, 2 <BR> <BR> <BR> <BR> <BR> # #<BR> <BR> <BR> 2 + # # # 3 - 2 2 <BR> <BR> <BR> <BR> <BR> # #<BR> <BR> <BR> # - 2 # # - 2 - 2 1 2 S(#)= H-H[ - sin(2#)] <BR> <BR> <BR> γ 2# γ<BR> <BR> <BR> <BR> <BR> <BR> <BR> #<BR> <BR> <BR> <BR> 3 -# # # 3 S(#)= H, 2 for the fourth stroke, as follows: <BR> <BR> <BR> <BR> <BR> #<BR> <BR> <BR> <BR> 3 # # # 3? + S(#)= H, 2 5 5 3 + + -< (p g 4P - - 2 2 <BR> <BR> <BR> <BR> <BR> <BR> <BR> 5 5 <BR> <BR> <BR> <BR> <BR> <BR> <BR> (p - 3P - - # - - 3P - - 2 1 2 S(#)= H-H[ - sin(2# <BR> <BR> <BR> <BR> γ 2# γ<BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> 5 4P - - # (p <- 4P S# = 0 2 The second derivatives of these functions are shown on fig. 3 where they form one continuous endless line and therefore the engine will work without dynamic impacts.

Each cam follower 5 of the cam mechanism /fig. 5 and 6a, b, c/ comprises body 7 having grooves in this case, where is possible to make reciprocating movement through guides 6 executed here as prism guides. The guides 6 are fixedly connected to the case of the engine. Between guides 6 and the body 7 there is a cage 8 with rolling elements 9 to diminish friction. This way linear bearings are formed to guide the cam followers 5. The body 7 is provided with roller 10 which can move through the groove of the cam 4. The body 7 of the cam follower 5 can be fixedly connected with the rod of the piston 3 /fig. 5/ and this way forms a real piston follower 11 as shown on fig. 8. On fig. 7 a-d are shown different embodiments of the assembly of the guides 6 and the body 7. The cam follower 5 can be executed not only as a real piston follower 11 but as simulating cam follower 12 which is not connected with the working piston /fig. 8/. Simulating followers 12 are used to improve the balance of the engine in its different embodiments, serving for balance. All cam followers 5 can be steadily located round the axis of the cam 4 as shown on fig. 9a and 9b, or to be combined in even number of units 5' steadily located round the axis, all units with equal number of equally located each other followers 5, as shown on fig. 9c, d and e. Besides, the number of followers 5 in the units 5' can be optional. This way is possible the build in of additional aggregates in the engine, as for example a compressor, without disturbance of the balance. The followers 5 or the units 5' of the cam followers can form at least one balanced group, in each one with the purpose of achieving balance, the cam followers 5, simulate followers 12 and/or real piston followers 11, or units 5' are with equal mass and are located steadily round and equidistant from the axis of the cam drum 4. Besides, the convexities from the curve ofthe cam are steadily located round its axis. Besides on movement ofthe followers 5, the accelerations of the said followers 5, which are equidistant from the beginning of each ascending and descending sector from the period of the curve are with equal value and sign. For example on fig. 13 the acceleration al for the first follower is with equal value and direction as the acceleration a5, a2 is equal to a6 etc. It is preferably the profile of the cam 4 to be executed with even number of convexities, at least four and the number of cam followers 5 or units 5' to be even, not less than four. Besides, this number is preferably to be divisible to the number of the cam curve's convexities and half of the number of convexities to be odd number. Alternatively, half of the number of the cam curve convexities can be even number which is not divisible to the number of the followers 5. For example under six pieces of cam followers 5 have six pieces of convexities on the cam's profile or under four pieces of cam followers 5 have ten pieces of convexities. In this embodiment when the number of dead positions increases the turnovers of the engine diminish proportionally and the moment of rotation increase, the power remaining fixed. This insures the overall dimensions of the engine to satisfy the concrete needs. The number of parts in the engine can diminish, for example can be eliminated the necessity of reducer for the big ship engines. Besides, the curve of the cam can be executed in such a way that on movement of the followers 5 the maximum and minimum values of the accelerations of these followers 5 which are located equidistantly from the middle of each ascending and descending sector are nearer to the beginning and to the end of each sector than to its middle, so as the maximum and minimum value of the difference from the products of the first and the second derivative from the beginning and the middle of each sector as per function for movement is minimal. This way can be improved the balance of the cam engine if the number of the working cylinders is even and they are steadily located round the axis of the engine.

As shown on fig. 10 the engine according to the invention can work with double acting piston followers 11, each of them provided in its both ends with coaxial pistons 3 moving in coaxial cylinders 2, located opposite each other. As shown on fig. 11 all the pistons 3 can be one-side located. One combination of differently oriented one-side acting real piston followers 11 is shown on fig. 12 where each two adjacent pistons 3 are oriented in opposite directions. These versions of orientation of the pistons 3 give the possibility to be liberated bigger spaces round the cam 4, to build in additional aggregates and to diminish the number of parts and cross clearances of the engine, keeping its working volume.

In one embodiment of the invention, outlined in fig. 13a and 13b with the functions for movement of the followers 5, the profile of the cam 4 is executed in such a way that additionally in the middle of all ascending and descending sectors there are rectilinear inclined sectors and the accelerations of the cam followers 12 and/or 1 1 in these sectors are equal to zero. It is preferably the rectilinear inclined sectors to be equal. It is preferably the size of these sectors to be such that the angle of rotation (p of the cam on movement of the cam follower over the said sectors to be different from the angle of rotation (p of the cam on movement of the cam follower over the rectilinear horizontal sectors in each convexity of the cam's profile. This way besides improving of the thermodynamic cycle and the balance of the engine is achieved better steadiness during work.

To insure cam engine's work without impacts additionally is provided coupling with permanent contact between the working surfaces 13 and 13' of the cam drum 4 and the contact elements 14 and 14' of the cam followers 5 on transition from top and bottom dead positions compensating the mounting gap between them /see fig. 15, 16, 17 and 18/. The contact surfaces 13 and 13' of the working profile of the cam 4 can be constructed according to equal or different functions having either different stroke or different phases of the strokes, or different stroke and different phases of the strokes. An example for different stroke is shown on fig. 14 where conventionally is accepted that transition is realized on top and bottom dead positions of the pistons. Besides, the contact elements 14 and 14', mounted over the rollers 10 of the cam followers 5 are chosen in such a way that diminish the friction of the coupling, in this case these are rolling bearings. The contact elements 14 and 14' are at least two, each one mounted to the same or to different rollers 10 and at least one of them is mounted to the corresponding roller 10 through elastic element 15 with possibility for preliminary tightening /fig. 1 6a and 16b/. On fig. 15 is shown an outlined example of contact coupling on top dead center for the cam 4 with working groove. It is shown that the two contacting bearings 14 and 14', thanks to the elastic suspension of one of them and the eccentricity of the two working surfaces 13 and 13' of the cam groove, eliminates the mounting gap and transition in dead center is realized without impacts. On fig. 16a and 16b are shown different ways of execution of the elastic element 15 with spring and deformable bush. The elastic element 15 serves to eliminate errors in the profile and helps to sustain permanent contact with the working curve of the cam. On fig. 17 is shown a cam follower 5 with two rollers 10, mounted on each of them contact element 14 or 14' Such a cam follower is enabled to work with cam 4 having working flange which can be with equal thickness in each section of the cam's axis through its prolongation. In this case one of the shoulders from the elasticaly suspended contact element 14' is produced with eccentricity e which is regulated to eliminate the mounting gap and compensate the wear and deformations upon exploitation. On fig. 18 is shown other embodiment where the cam 4 is component with working groove and each part 4 and 4' comprising one ofthe contact surfaces 13 and 13' of the groove. Here the contact surfaces 13 and 13' are displaced one another through the axis of roller 10 in such a way that each one contacts one of the contact elements 14 and 14', located on the axis of roller 10. On this embodiment the profiles of the surfaces 13 and 13' can be displaced towards the stroke of follower 5 forming eccentricity e, or the axis of the elastic suspended contact element 14' can be constructed with eccentricity with possibility for regulation. When the functions by which are produced the contact surfaces 13 and 13' are displaced one another towards the stroke of the cam follower 5, then the elastic element 15 must have the possibility to deform only within the difference of the stroke or the eccentricity e The cam engine can be provided with mechanism to change the compression ratio. On examining the embodiment shown on fig. 1 with one-side located piston-cylindrical groups and fig. 19, this mechanism comprises lifter 16, located coaxial to the shaft 1 under or above the cam 4. In one embodiment shown on fig. 19 the lifter 16 can include a body 17. To the internal face of the body 17 is attached coaxial thrust washer 18 without possibility of rotation against it and mounted on the face ofthe washer rolling elements 19 being in contact with one of the faces of coaxial controlling face cam 20. To compensate technological errors it is preferably the connection between the washer 18 and the body 17 to be executed as spherical bearing. The controlling cam 20 is in contact with driving elements 21 which in the shown embodiment are executed as hydraulic cylinders - toothed bars to set in motion the cam round the axis of the shaft 1. Over the other face of the controlling cam 20 are located rolling elements 22 which can be smooth /fig. 20d or 20e/ or profiled oval bodies /fig. 20a-c/.

The rolling elements 22 contact one of the faces of the executive cam 23. Over the rolling elements 22 contacting the face surfaces of the controlling cam 20 and/or of the executive cam 23 can be performed equal wavelike concavities and convexities connected smoothly as shown on fig. 20 b-e. The executive cam 23 is insured against rotation towards the body 17 and can execute only coaxial motion. Over the other face of the cam 23 are located other rolling elements 24 contacting one of the faces of the working cam drum 4. The mechanism changing the compression ratio includes also a unit 25 for axial movement of the cam 4 /fig.

1, 19, 21a, 21b and 22/. The unit 25 comprises rolling elements 26 which can be with different shape, for example spheres /fig. 19b/ or rollers /fig. 19a/. The rolling elements 26 are located in cage connecting the shaft 1 and the cam 4 with formed longitudinal grooves 27.

The grooves 27 can be parallel or inclined to the axis of the shaft 1 as shown on fig. 22. When the grooves 27 are inclined, additionally upon change of the compression ratio it is possible to influence the displacement of fuel-air mixture distributive phases. It is preferably to act elastic elements over the face of the cam 4, opposite to the lifter 16 for example tension springs 28, to eliminate the slippage upon movement of the working rolling elements 22 and the turning of the cam 4 in direction of diminishing the compression ratio. In other embodiment for mechanism regulating the compression ratio, especially suitable for building in of cam engine with two-side located piston-cylindrical groups, the engine comprises two working cams 4A and 4B as shown on fig. 23. There are two opposite acting and self-regulated mechanisms to control the compression ratio, located each one in the bottom of the corresponding cam. Each lifter 16A and 16B is executed as one-side acting hydraulic cylinder, whose piston 29 is hollow and insured against rotation. In this case of one-side acting coaxial hydraulic cylinder, for driving medium to return the cam 4 in direction of diminishing the compression ratio are used gases in the cylinders 2 and the elastic elements 28. To insure permanent contact between the piston 29 of the hydraulic cylinder and the corresponding working cam 4 on the face of the piston 29 is formed a flange 30 having cage with rolling elements 31. There is possibility the contact between the piston 29 and the cam 4 to be executed through an intermediate washer 32 located on the shaft 1 with possibility for axial displacement insured against rotation and through dividing rod 33, located parallel to the shaft 1 with possibility for axial displacement. This way can be achieved a change in the compression ratio in cylinders located on both sides or on each side of internal-combustion engine according to the needs, for example axially distanced from the hydraulic cylinder cam drum 4. The same is the case with two working cams 4A and 4B where the dividing rod 33 passes easily for example through the cam 4A and influences the second cam 4B, displacing it axially. It is preferably each two opposite followers 5 of cam engine with two-side located piston-cylindrical groups to be guided separately through own guides 6, provided with cages 8. If each same cams 4A and 4B are in phase (fig. 23) the balance is achieved according the above mentioned rules because each two coaxial followers 5 are moving as whole. If however the cams 4A and 4B are in counterphase so as the top dead point of any follower 5 responds to the top dead point of its coaxial follower 5, than the cam engine is always balanced independently from the number of followers 5 and the character of the curve of the cam 4, because the opposite accelerations of the coaxial followers 5 are always provided.

On fig. 24a and 24b is shown an embodiment, providing an optimum tightening between guides 6 and the bodies 7 of the followers 5. Each guide 6 is resting over at least one bearing surface of the case 34 of the engine with at least one own surface in such a way that there is possibility for lateral displacement, fixed through fasteners 35 - in this case screws. A mechanism for tightening 36 is located between two adjacent guides 6 for two adjacent followers 5. The mechanism 36 includes expansion screw 37 with special conical head 38, screwed in conical sleeve 39. The screw 37 and the sleeve 39 enter in the corresponding semipockets of at least two expanders 40, each one bearing one guide 6. In this case a third expander 40 is resting over a bearing surface ofthe case 34. On screwing a nut 41 to the screw 37 its conical head 38 and conical sleeve 39 influence the expander 40 in such a way that compress the guides 6 and eliminate eventual gaps. On fig. 25a is shown one other way of providing an optimum tightening between the guides 6 and the bodies 7 of the followers 5.

In this case between the contacting surfaces of the case 34 and each guide 6 in the corresponding pocket a collet 42 is located with tightening. The collet 42 being cross-like cut body as shown on fig. 25b. The perfect guidance through the above mentioned linear bearings of the followers 5 gives the possibility to provide bigger operational gap between the piston 3 and the cylinder 2 compensating bigger temperature expansion.

To stabilize the thermodynamic characteristics of the engine Ifig. 1, 26-32/it can be provided with a mechanism regulating the fuel-air mixture distribution with phase shift. It helps to establish optimum phases of fuel-air mixture distribution according to the changes in compression ratio and engine's turnovers. Commonly, the mechanism regulating the fuel-air mixture distribution comprises primary shaft 43, fixedly connected as prolongation of the working shaft 1. The primary shaft 43 can drive for example a fuel-injection pump, a current distributor etc. Through a regulator 44 coaxial to the primary shaft 43 is connected secondary hollow shaft 45 with possibility for axial and/or angle movement. A coaxial cam block of the fuel-air mixture distribution 46 is connected to the shaft 45 through splined connection. The cam block 46 comprises at least one cam profile 47 for the discharge valve 48 in case the engine is two-stroke. In case the engine is four-stroke the cam block 46 comprises two cam profiles and cam profile 49 for inlet valve 50. On fig. 1 and 26a-d is shown one embodiment for mechanism regulating the fuel-air mixture distribution with advancing phase shift of four- stroke engine whose cylinders act in direction of rotation of the cam 4. The mechanism comprises a regulator 44 of centrifugal type, shown in details on fig. 26 including fingers 51 of primary shaft 43, active weights 52, fingers 53 of secondary shaft 45 and springs 54. The working shaft 1 is connected fixedly to the primary shaft 43 through the fingers 51. The fingers 51 are in movable connection with grooves of suitable profile at the active weights 52, in this case two numbers, which are connected with the secondary hollow shaft 45 through the fixedly connected with them fingers 53. The fingers 51 and 53 are connected through calibrated springs 54. This way, when the engine rests or works with turnovers minimum resistible and similar to them, the active weights 52 are near to the secondary hollow shaft 45.

The primary shaft 43 and the secondary hollow shaft 45 are quiet one another and are rotating with the turnovers of the working shaft 1. On increasing the engine's turnovers the active weights 52 distance from the axis influenced by the centrifugal forces until reaching the casing 55 of the secondary hollow shaft 45. The fingers 51 move through the profile grooves of the active weights 52 and the distance between fingers 51 and 53 diminishes, the result is overcoming the resistance of springs 54 and additional rotation of the secondary shaft 45 towards the primary shaft 43 in direction of rotation. The cam block 46, connected with the shaft 45 changes its initial position towards the maximums and the minimums of the working curve of the cam 4. On fig. 27a-c is shown a version of regulator 44' of mechanism with retarding phase shift for the engine from fig. 1. The springs 54' of this regulator connect the active weights 52' with each other and one of their ends joins fingers 53' of the secondary shaft 45. On increasing the turnovers above definite number the weights 52' move away overcoming the resistance of springs 54'. Fingers 51' of the primary shaft 43 slip over the profile grooves of the active weights 52' and distance between fingers 51' and 53' increases.

This results in retarded rotation of the secondary shaft 45 towards the primary shaft 43 in direction of rotation and retarded phases of fuel-air mixture distribution. On fig. 28 is shown another mechanism regulating the fuel-air mixture distribution of toothed type. The primary shaft 43" and the secondary shaft 45" are connected with splined connection giving the possibility for axial displacement, for example slots. The regulator 44" is double acting hydraulic cylinder which moves axially the secondary shaft 45". The splined connection between the secondary shaft 45" and the cam block 46" of the fuel-air mixture distribution mechanism has slots inclined toward the axis, for example slots inclined to the left or to the right. This way upon command from the cylinder 44" the shaft 45" moves axially towards the primary shaft 43". The shaft 45" drives the cam block 46" upon its movement through the axis. As a result from the slot's inclination the block 46" advances or retards during rotation towards the shaft 45". If the splined connection between the shafts 43" and 45" has also inclined axial slots, there is additional possibility to regulate the phase shift of fuel-air mixture distribution. As shown on fig. 29a-c, the cam block 46 of the fuel-air mixture distributive mechanism can be executed component, in such a way that at least one of the cam profiles 47, 47A, 47B, 48, 48A and 48B has the possibility for driving from the primary shaft 43. This way it is more rationally to regulate the beginning and the continuity of the phases of fuel-air mixture distribution.

On fig. 30 is shown an example of four-stroke cam engine with fuel-air mixture distributive mechanism and working range of the working cylinders opposite to the direction of rotation of the cam 4. On fig. 33 is shown reversible block 56 for reversing the fuel-air mixture distributive mechanism, located between the working shaft 1 and the primary shaft 43. The block 56 comprises connected conical gears and the motion from the shaft 1 is transferred in direction, opposite to the primary shaft 43. On including of such reverse all curve's branches ofthe cam 4 are equally intensified. For example, with four-stroke engine the working range of the cylinders becomes 1-4-3-2 and each couple of adjacent ascending and descending curve's branches of the cam 4 are passing periodically through all working strokes of each working cylinder. This insures improved service resource of the engine. As shown on fig. 30 the cam block 46 ofthe fuel-air mixture distribution can be executed on the basis of lever multiplying transmitting mechanism 57 driving the valves 48 and 50. The regulator 44 in this case is of centrifugal type. On fig. 31a, 3 lib and 31c is shown cam block 46, where the suction 49 and discharging 47 cam profiles can be component as shown on fig.

29a, 29b and 29c and at least one of the profiles 47, 47A, 47B, 48, 48A and 48B is connected with the primary shaft 43 of the fuel-air mixture distributive mechanism. On fig. 32 is shown the engine from fig. 30 with rocker transmitting mechanism 58 for driving of valves 48 and 50. On fig. 34, 3 5a and 35b is shown engine with mechanism controlling the fuel-air mixture distribution and reversible block 59 located after the mechanism's regulator. In this case through the coupled connecting lateral conical gears 60A and 60B coaxial distributive shafts 61A and 61B can be driven, where cams 62 and 63 are located corresponding to the inlet 48 and discharging 50 valves of the working cylinders 2. Such an embodiment of the engine gives the possibility of changing its clearance and component according to the needs. The distributive shafts 61 can serve also for driving of different units and aggregates of the engine.

This engine certainly can be executed without mechanism regulating the fuel-air mixture distribution.

The cam engine according to the invention can be also executed as two-stroke engine.

Such an example is shown on fig. 36 and 37. It is possible for the cylinder block in which are located the cylindrical sleeves 64 of the working cylinders 2 to be formed with upper 65 and bottom 66 sectors, in each sector 65 and 66 radial cavities are formed, corresponding to 67 and 68 for circulation of the cooling liquid. The cylindrical block can be executed as monolithic or component. A hermetic space 69 is formed round each cylinder 2 in the upper sector 65 of the cylinder block connected through blowing-down windows 70 with the working chamber of the cylinder 2. The windows 70 are formed in each cylindrical sleeve 64.

In the space 69 which is continuously supplied from compressor, for example built in the engine, with fresh working substance, for example air, is created overpressure, necessary to clean the chamber from the combustion products. Discharging valves 72 are located in the cylinder head 71 to guide the combustion gases. The piston 3 is preferably to be with an additional seal 73 to prevent the leakage of fresh working substance into the space 69. Such an engine can be executed with one-side located cylinders including each of the above mentioned mechanisms. In comparison with the known two-stroke crank-rocker engines the described two-stroke cam engine whose cam is executed with curve according to the invention is more effective having similar thermodynamic cycle as shown on fig. 38b in comparison with fig. 38a.

The cam engine according to the invention can also be executed with Stirling cycle /see fig. 39 and 40/. On fig. 39 is shown such an engine with two equal cams 4C and 4D, located on the working shaft 1, turned to each other with their rectilinear horizontal sectors and dephased opposite one another under definite angle. The angle of dephasing is preferably to be round angle y where is realized each sector of the curve /fig. 42 and 43/. As shown on fig.

41 the working curve of each cam 4C and 4D is executed as periodical curve having period û and the number of periods is more than one. As shown on the figures each period consists of three sectors, realizing itself within the angle y. The sectors are ascending, rectilinear horizontal and descending, all with equal size and the horizontal rectilinear sectors included only in one-side located convexities of the curve. The curve of each cam can respond to the regulations for equal accelerations of the followers 5 which are equidistant from the beginning and/or the middle of each ascending and descending sector. It is preferably the followers 5 of each equalized group of followers 5 to be with equal mass and located steadily round the axis of the cams. Their number round each cam is divisible to the sector's number of the curve.

For example round cam with two periods and six sectors can be located six, twelve or eighteen etc. followers 5. This way is achieved maximum balance as to the engine as a whole, as to the followers round each cam. In one preferred embodiment the number of followers 5 round each cam is two times bigger than the sector's number of the curve and the maximum and minimum values of the accelerations of the followers 5 equidistanced from the middle of each ascending and descending sector are nearer to the beginning and to the end of each sector than to the middle, so as the maximum and minimum value of the difference from the products of the first and the second derivative from the beginning and the middle of each sector as per function for movement is minimal.

This way is achieved maximum balance for engine's operation. Certainly the followers in this case can be grouped in units 5", which form at least one balanced group of units 5" The engine from fig. 39 comprises at least one cylinder 2C for constantly high and cylinder 2D for constantly low temperature, located opposite each other in separate cylinder blocks for each type in, in this case round the corresponding cams 4C and 4D of the shaft 1 which is hollow. The working spaces of cylinders 2D for constantly low temperature are connected with cooler 74. Eventual leakage of the working substance, for example helium can be assembled in spaces 75, each one limited from piston 3C and 3D, cylinder 2C and 2D and diaphragm sealing 76 connecting the cylinder and the piston. Between the cylinders 2D for constantly low temperature coaxial to the shaft 1 is located heat exchanger 77 to cool the cooling agent, in this case water. The heat exchanger 77 has output to the space where is located the cooler 74. The cold oxidant, in this case air, is supplied through the central hole of the shaft 1. The shaft 1 has openings 78 for the cold air, connected with the space 79 round the heat exchanger 77. The space 79 is connected with rotating heater 80, in this case through openings 81' and 81" of the shaft 1. The heater 80, besides for preliminary heating of the air, serves also for continuous homogenization of the air-fuel mixture, as it is fixedly connected to and rotates together with the shaft 1 in the combustion chamber 82. Round the shaft 1 in the combustion chamber 82 are located the cylinders 2C, each one provided with heater 83 to heat the working substance. The heater 83 is connected with the space above the piston of the cylinder 2C. The combustion chamber 82 is provided with injector 84 to supply fuel and is connected with collector 85 to remove the combustion gases. The spaces above the pistons of each two coaxial cylinders 2C and 2D are connected and between them is located regenerator 86, being porous material. In the regenerator 86 is realized the removal or the acceptance of heat from the working substance. In this case both cams 4C and 4D are connected with the corresponding mechanism to change the compression ratio, whose lifters 1 6C and 1 6D are for example one-side acting hydraulic cylinders. The cams 4C and 4D are connected with the shaft 1 through corresponding mechanisms for axial displacement 25C and 25D. The grooves 27 of the mechanisms 25C and 25D can be upright or inclined towards the axis of the shaft 1.

In this case of inclined grooves of at least one of the mechanisms 25, besides change in the compression ratio it is possible to be realized additional dephasing of the working curve of the cams 4C and 4D one another. On fulfillment of the above mentioned conditions the engine works with more effective thermodynamic cycle /fig. 44b/ than the classic Stirling cycle /fig.

44a/. The effect of the additional dephasing on the thermodynamic cycle is shown on fig. 44c.

The better efficiency in this case is due to the compression or the expansion of the working substance which is realized almost entirely in the zones, where heat is removed or accepted and the acceptance or the removing of heat between the regenerator 86 and the working substance is realized almost in constant volume.

One other possible embodiment of effective, balanced, steadily working and easily regulated engine with Stirling cycle is shown on fig. 40. This engine works with one cam 4 and as shown on the figure, the cylinders 2E and 2F for constantly low and constantly high temperature are located steadily side by side and the next cylinder but one round the axis of the engine. The central angle between the axis of two adjacent cylinders 2E and 2F from different type is equal to the angle y of a sector from the cam's curve. The spaces above the pistons of each two cylinders 2E and 2F located one another under angle y, are connected through regenerator /not shown on the figure/.

In these cases the mounting of the combustion chamber with the engines of Stirling type between the cylinders with constant high temperature results in considerable decrease of the clearance and the number of details of the engine. Besides, the losses of effective heat are less.

The shown examples serve only for illustration and do not limit the scope of the invention, which is determined only by the following claims.