Abstract:
The invention relates to a piston cam engine used in different field of the mechanical engineering, as internal-combustion engines compressors, pumps etc. The cam engine comprises cylinders ( 13 ) with pistons ( 20 ), a cylindrical tubular 3D cam ( 3 ) having a cam groove on the inner cylindrical surface and at least two guides ( 10 ) which are guide columns. The cam ( 3 ) is composed and includes two coaxial bushes ( 3   a,    3   b ), each one having corrugated cam section ( 95   a  or  95   b ) from its one side and flange ( 35 ) from its other side besides the bushes ( 3   a,    3   b ) are positioned against each other with its corrugated ends at a distance from each other, and further comprises spacer ( 37 ) between the flanges ( 35 ) of the bushes ( 3   a,    3   b ), so as to form the cam groove having a constant section.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a piston cam engine and particularly to an opposite piston cam engine, used in different field of the mechanical engineering, as internal-combustion engines, compressors, pumps etc. Engines could be integrated in various land, water and air vehicles, as well as in stationary units. 
       BACKGROUND OF THE INVENTION 
       [0002]    The most important and perspective application of opposite piston mechanisms converting the reciprocal linear piston motion into rotation towards output shafts and vice versa is in the field of internal combustion engines. 
         [0003]    There are known from DE 3347859, RU 2069273, RU 2073092, RU 2089733, RU 2118472 etc., opposite piston cam engines comprising a housing, a drive or driven shaft, a cylindrical tubular 3D cam having a cam groove on the inner cylindrical surface, opposite coaxial cylinders mounted in the housing, as well as pistons moving in the cylinders and followers having end pieces for moving in the cam groove connected to the pistons. The opposite pistons of these known cam engines are fixed each other and have synchronized motion. Although these engines have a simplified construction and possibility for reduction of contact pressure that occurs in contact areas of the cam groove and end pieces of the followers, they have not elements moving in reciprocal of the pistons direction to create balance inertial force. 
         [0004]    There are also known from SU 1525284 and SU 1705600 another opposite piston cam engines including a housing, a drive or driven shaft, a cylindrical tubular 3D cam having a cam groove on the inner cylindrical surface, opposite coaxial cylinders mounted in the housing, as well as pistons moving in the cylinders connected with followers having end pieces for moving in the cam groove. Each piston of these engines has own follower having arm with end piece for independent movement in the cam groove. Thus it is possible for the pistons to move in opposite directions and their inertial forces to be neutralized. The end pieces for movement in the cam groove are rollers bearing by the free ends of the arms. The rectilinear movement of the pistons is ensured by other rollers mounted also on the free ends of the arms of the follower, but moving in a guide groove formed in the housing. It is a main disadvantage of these engines that the linear guidance of the followers is performed by guide groove which provokes arising of micro strokes in between the contact surfaces of the rollers and the groove when the direction of piston motion has changed. Besides in order to ensure precise guidance of the pistons, the cylinders and the pistons must be manufactured with a high precision. 3D cam is monolithic and it is difficult to produce the internal cam groove with high precision. All above complicates the technology and increases the manufacturing costs. 
       SUMMARY OF THE INVENTION 
       [0005]    The problem solved by the present invention is to provide a piston cam engine which is balanced and reliable, as well as noise and vibrations are decreased. 
         [0006]    This and other problems are solved by a piston cam engine comprising a housing, a drive or driven shaft, a cylindrical tubular 3D cam having a cam groove on the inner cylindrical surface. The 3D cam is composed. It includes two coaxial bushes, each one having corrugated cam section from its one side and flange from its other side, besides the bushes are positioned against each other with its corrugated ends in such a way that the convexities of one of the cam sections are positioned against concavities of the other at a distance from each other. The cam further comprises spacer between the flanges of the bushes, so as to form the cam groove having a constant section. There is a possibility the groove to be controlled for ensuring a permanent contact between the rollers and the corresponding cam section. Thus an endless corrugated cam groove on the inner cylindrical surface is performed, having constant cross section. The engine further comprises at least one cylinder, as well as at least one piston moving in the cylinder and at least one inertial balancer of the piston controlled by the cam. The engine further comprises at least two guides for linear reciprocal motion of each piston and each balancer, followers having at least two arms connected to the pistons and to the balancers. The guides according to the invention are guide columns, parallel and equally placed compared to the axes of the cam. Each one of the followers is equally placed compared to the axes of power transmission. On the ends of the arms rollers are mounted for moving in the cam groove. In the engine according to the invention the micro impacts between the contact surfaces of the rollers and the cam groove are avoided when the direction of piston motion has changed. The manufacturing costs decreases since it is not necessary for providing of high precision of guidance a high precision of manufacturing of pistons and cylinders. 
         [0007]    In one embodiment of the invention the guides are fixed to the housing, and the followers have a possibility to move axially on the guides. In one alternative embodiment the reverse is true, namely the followers are fixed to the housing, and the guides have the possibility to move axially on the guides. 
         [0008]    In another embodiment of the engine according to the present invention the cross section of each cam section is a line arranged at angle of degrees different from 90° in towards the axes of the cam which arrangement ensuring a reaction having radial component from the cam section when contacting the roller, and the radial component direction is directed to the axes of the cam. This radial component leads to discharge of the arms of followers, because it eliminates a part of the moment caused by the axial component of the same total reaction. 
         [0009]    In yet another embodiment of the invention the end of each arm is formed as a main bearing journal which free end forms additional bearing journal eccentric disposed compared to the main bearing journal. The roller is mounted on the main bearing journal and an additional roller is mounted on the additional bearing journal, so as the main roller and the additional roller contact with the opposite cam sections of the cam. The additional rollers ensure contact with the opposite cam of the cam section contacting with the main rollers. Thus it prevents the contact between each follower and the cam from interruption when the direction of the loading force has changed. Between the additional bearing journal and the additional roller has elastic element ensuring self-aligning toward the cam sections. In one alternative embodiment of the invention the axes of each arm is a straight line coinciding with the direction of the contact reaction in top dead center of the piston. The end of each arm is formed as a fork, and on fork arms a main bearing journal is immovably mounted, carrying the main roller. The main bearing journal is tube-like shaped, in which hole an additional bearing journal is positioned having axes parallel to the arm, on which additional journal an additional roller is mounted. The additional bearing journal has a possibility for movement on the axes of the main bearing journal, as the main roller and the additional roller each contacts with the one of opposite cam sections of the cam. 
         [0010]    In one another embodiment the piston cam engine according to the invention further comprises at least one cylinder head including variable means for delivery and means for discharge of working fluid. Thus the engine may be build in and to operate as compressor or pump. 
         [0011]    In one next embodiment of the invention the corrugated cam section is made so that its curve of law of motion of the followers in function of the angle of cam rotation is formed by consecutively alternating ascending and descending sectors in which connection equal number of convexities and concavities are obtained, which total number is equal to or multiple to the sum of the number of arms of the followers. At that the curve is continuous at least up to its second derivative within one complete cam rotation of 360°. Besides the curve is symmetrical for every two adjacent ascending and descending sectors toward a line passing trough its point of junction and the line is perpendicular to the tangent to the curve in this point, as well as the curve is symmetrical toward the middle point of a given ascending or descending sector. This embodiment of the cam curve ensures the velocities and accelerations of the followers at the end of each ascending and descending sector to be equal of their velocities and accelerations in the beginning of the next section, which in its turn leads to achieve a graded junction when the followers change their direction of movement to one preferred embodiment each ascending or descending sector of the curve has by one maximal and by one minimal value of its second derivative which are displaced from the end points of the given sector. In one more preferred embodiment the values of the second derivative of the curve are equal to zero in the points of connection of each two adjacent sectors. In one most preferred embodiment equal rectilinear sectors are included in the zone of points of connection of the curve. Thus the accelerations are equal by size and adverse by direction when comparing the accelerations of given follower at any two of its positions which are equal remote from the middle point of any ascending or descending sector. Such curve provides a simultaneous contact of all main bearing journals of followers with the respective cam profiles. Thus the piston cam engine according to the invention is completely balance at each working stage. 
         [0012]    In one another embodiment the piston cam engine according to the invention comprises more than one drive or driven shaft, each one rotary moved by the cam. 
         [0013]    In one next embodiment the drive or driven shaft transmits or accepts motion from the cam by means of chain drive. 
         [0014]    The invention further provides a compressor or pump including at least one piston cam engine according to the embodiments described above. 
         [0015]    The present invention also provides a motor including the piston cam engine according to the embodiments described above. 
         [0016]    In one embodiment the motor is an internal-combustion engine, which valve-timing mechanism includes at least one kinematic chain having one discharge or one inlet cam on its one end and valve on its other end, both connected by a rocker with roller. The roller contacts to the discharge or inlet cam. The discharge or inlet cam is a flat 2D cam fixed coaxially to the main cam of the piston cam engine. The rocker is connected by a hinge to the housing of the engine. 
         [0017]    In yet another embodiment the motor is a four-stroke two-piston engine, which valve-timing mechanism consists of four kinematic chains, two of which are discharge and the other two are inlet chains, which kinematic chains are located by two different discharge and inlet chains of each side of the main cam. 
         [0018]    In another embodiment the motor is four-stroke one-piston engine, which valve-timing mechanism consists of two kinematic chains, one of which is discharge chain and the other is inlet chain, which kinematic chains are located on the side of the cylinder. 
         [0019]    Another embodiment provides a two-stroke two-piston engine, which valve-timing mechanism consists of two kinematic discharge chains located by one of each side of the main cam, and the power supplying with fresh working substance is from windows of each cylinder. 
         [0020]    The another embodiment of the invention further provides a motor which is a two-stroke one-piston engine, having valve-timing mechanism consisting of one kinematic discharge chain. 
         [0021]    The next embodiment discloses a motor comprising one operating cylinder working at four- or two-stroke process, and one opposite cylinder which is cylinder of compressor or pump. In one preferred embodiment the opposite cylinder is a cylinder of compressor, and at least a part of the compressed air from the compressor cylinder feeds the operating cylinder through a pneumatic accumulator where the air is stored and/or fuel-air mixture is prepared for the next working cycle of the operating cylinder. 
         [0022]    In yet another embodiment the motor comprises more than one piston cam engine, each of which represents separate module, and the modules are kinematic connected each other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  shows a longitudinal section of piston engine passing through the axes of two opposite guiding columns; 
           [0024]      FIGS. 2   a ,  2   b  and  2   c  are three-dimensional views of one two-arm and one three-arm follower and a variant of follower with centering journal which meet the requirements for followers of piston cam engine according to the invention; 
           [0025]      FIGS. 3   a ,  3   b ,  3   c  and  3   d  are respectively views, partial section and auxiliary view of a composite follower; 
           [0026]      FIGS. 4   a  and  4   b  are two variants for guiding of followers of two-piston cam engine according to the invention; 
           [0027]      FIG. 5  is an axonometric view of partial section of the main cam and gearing for rotation output or input; 
           [0028]      FIG. 6  shows a cam section with plate inserted; 
           [0029]      FIG. 7  shows a sloping cam section made radial unloading reaction to the follower; 
           [0030]      FIGS. 8   a  and  8   b  show respectively longitudinal and cross section of piston engine with modified followers and curvilinear cam section; 
           [0031]      FIG. 9  shows the properties of the law of movement of the followers; 
           [0032]      FIG. 10  is a two-piston cam compressor; 
           [0033]      FIG. 11  represents a longitudinal section of two-piston four-stroke internal combustion cam engine passing through the axes of the valves and its main cam; 
           [0034]      FIG. 12  shows two-piston two-stroke internal combustion cam engine; 
           [0035]      FIGS. 13   a ,  13   b  and  13   c  show respectively one-piston compressor, one-piston four-stroke engine and one-piston two-stroke engine according to the invention; 
           [0036]      FIGS. 14   a  and  14   b  show respectively four- and two-stroke engine combined with a compressor; 
           [0037]      FIGS. 15   a  and  15   b  show respectively two laws of followers movement and their second derivatives that are continuous and which extreme values do not coincide with the end points of their sectors; 
           [0038]      FIGS. 16   a  and  16   b  show a law of follower&#39;s movement and its second derivative with introduced rectilinear horizontal sectors in each point of the curve corresponding to pistons dead position; 
           [0039]      FIGS. 17   a  and  17   b  show thermodynamic cycle respectively of a traditional four-stroke diesel engine and of a cam four-stroke diesel engine according to the invention; 
           [0040]      FIG. 18  shows internal combustion engine composites of two modules; 
           [0041]      FIG. 19  shows the connection between the shaping of the cam sections and the law of piston motion. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0042]    According to the invention different two- and one-piston engines could be realized that may afterwards be build in compressors, pumps, internal combustion engines performing different working cycles, as well as internal combustion engines combined with a pump or compressor. 
         [0043]      FIG. 1  shows one preferred embodiment of a two-piston cam engine according to the invention. The engine comprises two followers  1  that are monolithic in that case and each one has two arms  26 . To their free endings that are formed as main bearing journals  4 , main rollers are mounted  2  that are in contact with their corresponding curved sector of main transformation cam  3 . Additional bearing journal  5  is attached to the front part of each main bearing journal  4 , on which journal  5  elastic element  6 , bush in this case, another bush  7  and additional roller  8  are mounted. The additional roller  8  is in contact with the cam curve that is opposite to cam curve the main rollers  2  are in contact. The axes of additional bearing journals  5  are parallel to the axes of their corresponding main bearing journals  4 , but they are displaced against them in direction parallel to the axis of given follower in direction to common end of its arms  26 . A spacer washer  9  is mounted between each main bearing journal  4  and its corresponding additional bearing journal  5  that prevents the contact between the main roller  2  and additional roller  8  rotating in different directions. Between each arm  26  and its corresponding main bearing journal  4  there is an opening which axis is parallel to the direction of loading force to the respective follower. In these opening there are guiding columns  10  with round cross section in this case. In sown example the connection between the guiding columns  10  and the followers  1  is fixed. Each guiding column  10  on its turn is guided in its two endings by linear bearings  11  placed in housing  12 , namely two opposite cylinder blocks. In the blocks  12  there are also opposite cylinders  13  and bearing rings  14 . In one of the two cylinder blocks  12  there are screw holes in which binder screws  15  are screwed that are protected against self-unscrewing by means of fixing bolts  16 . The bolts  16  are screwed in the corresponding binder screws  15  with reverse threads and are protected against self-unscrewing by means of spring washers  17 . The binder screws  15  exert rated pressure on bearing ring  14  of axial bearing  24  and eliminate undesirable axial clearances both in axial bearings  24  and between cam curves and rolling rollers  2  and  8  of followers  1 . The cylinder blocks  12  close bilaterally a crankcase  18  by means of threaded joints  19  which could be seen on  FIG. 12 . In the two operating cylinders  13  there are pistons  20  having compression rings  21 . Pistons  20  are fixed to the unitary endings of the arms  26  of each follower by means of bolts  22 . In this case pairs of cylindrical locators  23  are used for centering between the followers and pistons  20 , connected respectively to the arms  26  of given follower  1  and the rod of the corresponding piston  20 . The fit between the pairs of cylinder locators  23  is a guaranteed clearance fit, which gives opportunity each piston  20  for self-adjusting in the corresponding cylinder  13 . The contact front parts of the locators  23  could be manufactured so as to ensure parallelism between axes of piston  20  and their corresponding cylinders  13  and do not prevent pistons  2 Q self-adjusting. In this particular case the bearing of the cam  3  in the opposite cylinder blocks  12  is frontal by means of axial rolling bearings  24  and radial by means of friction bearings  25 . The piston cam engine according to the present invention is suitable for unifying of its units, thus allowing flexibility in the manufacturing of different modifications. 
         [0044]    Axonometric views of followers, namely having two and three arms  26  and an example of follower with a centering journal are shown on  FIGS. 2   a ,  2   b  and  2   c . It is typical for the two-arm follower  1  that its axis of symmetry coincides with the axis  90  of loading force to the follower  1 . Additional effect from the use of more than two arms  26  for one follower is the increase of the number of contacts between the follower and its respective cam curve which leads to more uniform distribution of summary piston force on the cam curve, reduces its wearing out thus prolonging the piston cam engine life of operation. 
         [0045]      FIGS. 3   a ,  3   b ,  3   c  and  3   d  show respectively views, partial section and auxiliary view of a composite follower  1  having four separate arms  26  twos connected. In the one end of each arm  26  there is a channel with rectangular cross section in which a connector  28  by means of fitting pins  27  is adjusted to the arms  26 . The two sides of the channel embrace the front parts of the connector  28 . The fitting pins  27  are in parallel to the direction of loading force of the follower  1 . Each arm  26  is connected to the connector  28  with two adjusting screws  29  and one retainer screw  30 . The fixing screw passes through a reniforme opening  31  of the arm  26  and is screwed in a screw hole of connector  28 . This example embodiment allows independent adjustment of the arm  26  position.  FIG. 3   d  shows a follower having four arms  26 , two of which lying opposite each other together with the connector  28  form a monolithic detail, while the other two arms  26  are connected to the connector  28  as described above. Using composite followers  1  will facilitate their manufacturing in cases when the arms  26  are more than two or when overall dimensions are large. 
         [0046]      FIGS. 4   a  and  4   b  shows two example embodiments of follower guiding of the piston engine according to the invention. In the first embodiment shown on  FIG. 4   a  each column  10  is fixed to its corresponding arm  26 , and its connection  11  to the housing is axially-movable. In the second embodiment shown on  FIG. 4   b  each guiding column  10  is fixed to engine housing and the connection  11  with its corresponding arm  26  is axially movable. These connections  11  allow reciprocal motion of the followers  1  in parallel to their own lines of loading force. The connections  11  could be made as friction bearing or rolling axial bearings. The fixed connections are shown with “X” on the drawing. The second embodiment of  FIG. 4   b  of the disclosed piston engine is preferable in cases when the followers&#39; guiding is reliable, for example guiding of follower having more than two arms. 
         [0047]      FIG. 5  shows an axonometric view of the cam  3  of the piston cam engine of  FIG. 1 . This cam  3  comprises two identical cam bushes  3   a  and  3   b . On one side of these bushes there are cam curves having two concavities and two convexities each and the sum of total number concavities and convexities is equal or multiple to the sum of arms  26  number of the two followers  1 . On the other side of each cam bush there is internal ring-shaped cut-out  32  for friction radial bearings  25 , semicircular channel  33  for the balls of the rolling axial bearings  24 , adjusting ring  34  for orientation of the first cam bush  3   a  against the other one  3   b  and flange  35  for fastening of means for fluid flows control. In this case the means for control are flat 2D cams  36 . The axes of cam bushes  3   a  and  3   b  coincide, while their cam curves are turned opposite each other as the convexities of one of the curves are positioned against the concavities of the other one thus forming the cam groove. The reciprocal position of the two cam bushes  3   a  and  3   b  is implemented by means of a spacer  37 . In one preferred embodiment the spacer  37  is fixed with one of the cam bushes  3   a , and its fitting with the other cam bush  3   b  allows axial movement between each other. Thus the cam grove width could be adjusted.  FIG. 5  shows a gearing  38 , accepting or taking out the rotation. One of the gears  38   a  is fixed to the spacer  37 , and the other  38   b  is fixed to a shaft  39  that is placed in engine housing, which could be seen on  FIGS. 4   a  and  4   b.    
         [0048]    The embodiment shown on  FIGS. 6   a  and  6   b  increases the reliability and wear resistance of the main cam  3  of the disclosed piston engine without significantly raising its price.  FIG. 6   a  shows a cross section of a cam bush  3   a  or  3   b  passing through its own axis and a point corresponding to one top dead center of the pistons  20 . It could be seen that there are plates  40  made of material resistant to high contact pressure, which plates  40  are mechanically fastened on the most loaded parts of the cam profile, which usually are the areas around the top dead centers. In this shown embodiment the plate is fixed together with thread fastening element  41  that passes through an opening into the wall of cam bush  3   a  or  3   b , parallel to its axis and goes into a recess  42 , where by means of a nut  43  the plate  40  is pressed on the lower plane of curve of the bush  3   a  or  3   b .  FIG. 6   b  is a view of one of the cam bushes  3   a  or  3   b  towards its cam profile and in direction of its axis. When mounting the plate  4 Q is pressed to the spacer  37  by screwed joint of a screw  44  and nut  45 . By using of wear-resistant plate  40  the possibility any vacancies between the plate  40  and the main material of the cam bush  3   a  or  3   b  to occur is avoided. The cam bushes according to the invention are chipper than the monolithic, and when the plate  40  is worn out it could be easy replaced with a new one. 
         [0049]      FIG. 7  shows a sloping cam cross section, creating a radial unloaded reaction to the arms  26 ′ when the cross-section of cam curve has an inside edge  95 ′ lower than the outside  95 ″ one. Thus it is possible to control the direction of the reaction from the cam curve to the arms  26 ′. The contact area between the cam curve  95  and the main rollers  2 ′ of the arms  26 ′ become wider and it appears a radial component of the reaction from the cam curve  95  to the arm  26 ′. The expanded contact area reduces its contact pressures in contact surfaces, while the radial reaction unloads the arms  26 ′ of followers  1  by means of the moment created by it that eliminates part of the moment of axial component of the general cam reaction. 
         [0050]    Further opportunity for increasing the loading capacity of followers  1  is shown on  FIGS. 8   a  and  8   b  that are respectively a longitudinal and cross section of the described piston engine with modified followers. In the present example the axes of each arm  26 ′ is a straight line coinciding with the direction of contact reaction in top dead center of piston  20 . The end of each arm  26 ′ is formed as a fork, in which arms a main bearing journal  4 ′ are fixed, in this case by clamps  93  and threaded joint, on which a main roller  2 ′ is mounted. The main bearing journal ( 4 ′) is tube-like shaped, in which hole an additional bearing journal ( 5 ′) is positioned having axes parallel to the arm ( 26 ′), on which journal ( 5 ′) an additional roller ( 8 ′) is mounted. The additional bearing journal ( 5 ′) has a possibility for movement on the axes of the main bearing journal ( 4 ′), as the main roller ( 2 ′) and the additional roller ( 8 ′) each contacts with the one of opposite cam sections ( 95   a ,  95   b ) of the cam ( 3 ). In this case the cam curve of the main cam  3  is composed by a straight horizontal line and an arc, which is the active part of the cam curve. The main rollers  2 ′ in this case have arch-shaped cross section corresponding to the cam curve with which the rollers  2 ′ are in contact with. Roller  8 ′ contacts with the cam curve as the additional bearing journal  5 ′ is pressed by means of plunger  88  and spring  6 ′ leaning on cap  89 . A connecting element  91  binds the followers  1  and the guiding columns  10 . The main advantage of the disclosed embodiment is that the loading forces to the arms  26 ′ provoke mainly compression loads in the arms, but not buckling or torsional loads which lead to metal fatigue. 
         [0051]      FIG. 9  shows a preferred cam law motion of followers in development. Total number of concavities and convexities of law curve corresponds to the total number of arms of the two followers in examples of  FIG. 1 ,  FIG. 4  and  FIG. 5 , and in this case is four. It is shown also symmetry between each two adjacent sectors and symmetry of points inside each ascending  101  and descending  102  sector against its middle point. 
         [0052]      FIG. 10  shows a two-piston cam compressor or pump, where to the described piston cam engine a cylinder head  46 , comprising means  47  and  48  for supply and discharge of fluid. 
         [0053]    The adapting of the piston cam engine according to the invention to a four-stroke internal combustion engine is shown on  FIG. 11 . The valve timing mechanism comprises at least one kinematic chain, four in this case, each of them having valve  49  at one of its end, as well as one discharge  50  or one inlet  51  cams at the other end, connected together by means of rocker  52  having roller  53 . The discharge  50  or inlet  51  cam is a flat 2D cam, which is fixed coaxially to the main cam  3  of the piston cam engine. The rocker  52  is connected by a hinge  54  to the housing of the engine. The valve  49  is connected to the rocker  52  by adjusting screw  55  having spherical end piece  56  secured by nut  57 . Between each adjusting screw  55  and the front part of the stem of the respective valve  49  there is a cylindrical pad  58  for preserving the reliable contact between adjusting screws  55  and valves  49  when disturbing the parallel position of their axes during valves operation. The valves are driven by guiding bushes  59  positioned in two cylinder heads  60 , which tightly close the working cylinders  13 . The valves shown on  FIG. 11  make by known manner an additional sealing contact with their adjacent cylinder heads by means of preliminary tightening of return springs  61  connected with their respective valves  49  by means of valve disk  62  and binary conic bushes  63 . There is a sealing conic bush  64  between each valve  49  and cylinder head  60 . Seats  65  for return springs  61  have been formed in cylinder heads  60 , as well as openings  66  for nozzles, channels  67  and  68  for working fluid inlet and outlet port, spaces  69  for circulation of the cooling fluid, and combustion chambers  70 . 
         [0054]      FIG. 12  shows a two-piston two-stroke internal combustion engine comprising the cam engine according to the invention. In that particular case there do two cylinder heads  77  and a valve timing mechanism having two kinematic chains, each of them comprise one discharge cam  78 . The supply of fresh working medium is carried out by means of windows  79  made on each cylinder  13  in the places corresponding to the bottom dead center of the pistons. Each of the cylinder blocks has internal ring gaps  80  and seals  81  around the windows  79 . These ring gaps  80  are supplied with fresh working medium, which pressure is higher than the pressure of the working fluid in the supplied cylinder, when its windows start to open. The air inlet to the ring gaps  80  becomes possible through openings  82  in cylinder blocks. 
         [0055]      FIGS. 13   a ,  13   b  and  13   c  show respectively a single-piston cam compressor, a single-piston four-stroke cam engine and a single-piston two-stroke cam engine are shown according to the invention. All of them are made on the basic of the piston cam engine shown on  FIG. 4   b . Each one of them has been developed after changing one of its pistons and the corresponding cylinder with a balancer  84 . The cylinder block of the removed cylinder has been replaced with a closing cover  83 . The single-cylinder cam engines of  FIG. 13  are more economical. They are useful for small working volumes and where the requirement for steadiness of engines operation is not always high. Besides they are convenient for the purposes of research and experimental activity. It is easy to transform them into the two-piston cam engine described above. 
         [0056]      FIGS. 14   a  and  14   b  show different embodiments of combined two-piston cam engine with a compressor.  FIG. 14   a  refers to a four-stroke engine, and  FIG. 14   b —to a two-stroke one. Each of the shown embodiments comprises compressor cylinder  87  having means  47 ,  48  for supply and discharge of working fluid. The differences between them are connected with their energy-supplying cylinders  86 . In both cases it is shown, that at least a part of the compressed air from the compressor  87  is directed to the operating cylinders  86  for enrichment of the fuel mixture, as a pneumatic accumulator  85  is provided for storage and air or fuel-air mixture supplying for the next thermo-dynamic cycle. This embodiment is suitable in the cases when the consumer needs mechanical and pneumatic energy at one and the same time and when the steadiness of rotation moment of the outlet shaft is not an important factor. 
         [0057]    The efficiency of cam engines could be increased by improvement the cam law motion, as it is shown on  FIGS. 15   a  and  15   b . The first drawing on  FIG. 15   a  shows two cam laws motion with different degree of retardation of their pistons around their dead centers. Their corresponding second derivatives are given on  FIG. 15   b  below. It is evident from this drawing that each sector of the law, irrespective of the fact whether it is ascending  101  or descending  102  one, is characterized with one explicitly expressed maximum  109  and one explicitly expressed minimum  110  of its second derivatives or the same but in reverse sequence (minimum-maximum), which do not coincide with the end points  113  of the section to which they belong. The second derivative, represented with a continuous line, differs by that its values  111  in the ends of each section equal to zero. The continuity of the second derivative of the cam law leads to smooth movement of followers. 
         [0058]    In the following  FIGS. 16   a  and  16   b  a cam law motion and its second derivate are shown. In the law curve equal rectilinear sections  112  are integrated in each point, which corresponds to the dead centers of the pistons. On  FIG. 16   a  it is shown that the second derivate is continuous, without of interruption, because the values of the second derivative in the ends of each ascending  101  and descending  102  sectors equal to zero. One example of cam law motion as cycloid function is represented on  FIG. 16   a . 
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                   ] 
                 
               
             
             , 
           
         
       
     
         [0000]    through which the ascending and descending sectors of the cam law motion may be presented, where φ is the angle of cam rotation  3 , S(φ) is the cam law motion, H is the piston stroke and γ is the angle of cam rotation  3 , within which the piston  20  realizes its stroke. For the given example, pistons  20  perform four strokes per one revolution of the cam  3  and four times are immovable keeping constant cylinder volume, each time in the course of δ[deg CrAng]. The relation between γ and δ may be presented by means of the following equation: 
         [0000]      4δ+4γ=360°.
 
         [0059]    The specific forms of the cycloid function for each ascending  101  and descending  102  sector of the law are given in the table below, as well as the introduced rectilinear horizontal sections  112 . 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
               
                 Type of Section 
                 Range of Section 
                 Law of Section 
               
               
                   
               
             
             
               
                 1. Rectilinear 
                 
                   
                     
                       
                         0 
                         ≤ 
                         ϕ 
                         ≤ 
                         
                           δ 
                           2 
                         
                       
                     
                   
                 
                 S(φ) = 0 
               
               
                   
               
               
                 2. Ascending 
                 
                   
                     
                       
                         
                           δ 
                           2 
                         
                         ≤ 
                         ϕ 
                         ≤ 
                         
                           γ 
                           + 
                           
                             δ 
                             2 
                           
                         
                       
                     
                   
                 
                 
                   
                     
                       
                         
                           S 
                            
                           
                             ( 
                             ϕ 
                             ) 
                           
                         
                         = 
                         
                           H 
                           · 
                           
                             [ 
                             
                               
                                 
                                   ϕ 
                                   - 
                                   
                                     δ 
                                     2 
                                   
                                 
                                 γ 
                               
                               - 
                               
                                 
                                   1 
                                   
                                     2 
                                     · 
                                     π 
                                   
                                 
                                 · 
                                 
                                   sin 
                                    
                                   
                                     ( 
                                     
                                       2 
                                        
                                       π 
                                        
                                       
                                         
                                           ϕ 
                                           - 
                                           
                                             δ 
                                             2 
                                           
                                         
                                         γ 
                                       
                                     
                                     ) 
                                   
                                 
                               
                             
                             ] 
                           
                         
                       
                     
                   
                 
               
               
                   
               
               
                 3. Rectilinear 
                 
                   
                     
                       
                         
                           γ 
                           + 
                           
                             δ 
                             2 
                           
                         
                         ≤ 
                         ϕ 
                         ≤ 
                         
                           γ 
                           + 
                           
                             
                               3 
                               2 
                             
                              
                             δ 
                           
                         
                       
                     
                   
                 
                 S(φ) = H 
               
               
                   
               
               
                 4. Descending 
                 
                   
                     
                       
                         
                           γ 
                           + 
                           
                             
                               3 
                               2 
                             
                              
                             δ 
                           
                         
                         ≤ 
                         ϕ 
                         ≤ 
                         
                           
                             2 
                              
                             γ 
                           
                           + 
                           
                             
                               3 
                               2 
                             
                              
                             δ 
                           
                         
                       
                     
                   
                 
                 
                   
                     
                       
                         
                           S 
                            
                           
                             ( 
                             ϕ 
                             ) 
                           
                         
                         = 
                         
                           H 
                           - 
                           
                             H 
                             · 
                             
                               [ 
                               
                                 
                                   
                                     ϕ 
                                     - 
                                     γ 
                                     - 
                                     
                                       
                                         3 
                                         2 
                                       
                                        
                                       δ 
                                     
                                   
                                   γ 
                                 
                                 - 
                                 
                                   
                                     1 
                                     
                                       2 
                                       · 
                                       π 
                                     
                                   
                                   · 
                                   
                                     sin 
                                      
                                     
                                       ( 
                                       
                                         2 
                                          
                                         π 
                                          
                                         
                                           
                                             ϕ 
                                             - 
                                             γ 
                                             - 
                                             
                                               
                                                 3 
                                                 2 
                                               
                                                
                                               δ 
                                             
                                           
                                           γ 
                                         
                                       
                                       ) 
                                     
                                   
                                 
                               
                               ] 
                             
                           
                         
                       
                     
                   
                 
               
               
                   
               
               
                 5. Rectilinear 
                 
                   
                     
                       
                         
                           
                             2 
                              
                             γ 
                           
                           + 
                           
                             
                               3 
                               2 
                             
                              
                             δ 
                           
                         
                         ≤ 
                         ϕ 
                         ≤ 
                         
                           
                             2 
                              
                             γ 
                           
                           + 
                           
                             
                               5 
                               2 
                             
                              
                             δ 
                           
                         
                       
                     
                   
                 
                 S(φ) = 0 
               
               
                   
               
               
                 6. Ascending 
                 
                   
                     
                       
                         
                           
                             2 
                              
                             γ 
                           
                           + 
                           
                             
                               5 
                               2 
                             
                              
                             δ 
                           
                         
                         ≤ 
                         ϕ 
                         ≤ 
                         
                           
                             3 
                              
                             γ 
                           
                           + 
                           
                             
                               5 
                               2 
                             
                              
                             δ 
                           
                         
                       
                     
                   
                 
                 
                   
                     
                       
                         
                           S 
                            
                           
                             ( 
                             ϕ 
                             ) 
                           
                         
                         = 
                         
                           H 
                           · 
                           
                             [ 
                             
                               
                                 
                                   ϕ 
                                   - 
                                   
                                     2 
                                      
                                     γ 
                                   
                                   - 
                                   
                                     
                                       5 
                                       2 
                                     
                                      
                                     δ 
                                   
                                 
                                 γ 
                               
                               - 
                               
                                 
                                   1 
                                   
                                     2 
                                     · 
                                     π 
                                   
                                 
                                 · 
                                 
                                   sin 
                                    
                                   
                                     ( 
                                     
                                       2 
                                        
                                       π 
                                        
                                       
                                         
                                           ϕ 
                                           - 
                                           
                                             2 
                                              
                                             γ 
                                           
                                           - 
                                           
                                             
                                               5 
                                               2 
                                             
                                              
                                             δ 
                                           
                                         
                                         γ 
                                       
                                     
                                     ) 
                                   
                                 
                               
                             
                             ] 
                           
                         
                       
                     
                   
                 
               
               
                   
               
               
                 7. Rectilinear 
                 
                   
                     
                       
                         
                           
                             3 
                              
                             γ 
                           
                           + 
                           
                             
                               5 
                               2 
                             
                              
                             δ 
                           
                         
                         ≤ 
                         ϕ 
                         ≤ 
                         
                           
                             3 
                              
                             γ 
                           
                           + 
                           
                             
                               7 
                               2 
                             
                              
                             δ 
                           
                         
                       
                     
                   
                 
                 S(φ) = H 
               
               
                   
               
               
                 8. Descending 
                 
                   
                     
                       
                         
                           
                             3 
                              
                             γ 
                           
                           + 
                           
                             
                               7 
                               2 
                             
                              
                             δ 
                           
                         
                         ≤ 
                         ϕ 
                         ≤ 
                         
                           
                             4 
                              
                             γ 
                           
                           + 
                           
                             
                               7 
                               2 
                             
                              
                             δ 
                           
                         
                       
                     
                   
                 
                 
                   
                     
                       
                         
                           S 
                            
                           
                             ( 
                             ϕ 
                             ) 
                           
                         
                         = 
                         
                           H 
                           - 
                           
                             H 
                             · 
                             
                               [ 
                               
                                 
                                   
                                     ϕ 
                                     - 
                                     
                                       3 
                                        
                                       γ 
                                     
                                     - 
                                     
                                       7 
                                       2 
                                     
                                   
                                   γ 
                                 
                                 - 
                                 
                                   
                                     1 
                                     
                                       2 
                                       · 
                                       π 
                                     
                                   
                                   · 
                                   
                                     sin 
                                      
                                     
                                       ( 
                                       
                                         2 
                                          
                                         π 
                                          
                                         
                                           
                                             ϕ 
                                             - 
                                             
                                               3 
                                                
                                               γ 
                                             
                                             - 
                                             
                                               7 
                                               2 
                                             
                                           
                                           γ 
                                         
                                       
                                       ) 
                                     
                                   
                                 
                               
                               ] 
                             
                           
                         
                       
                     
                   
                 
               
               
                   
               
               
                 9. Rectilinear 
                 
                   
                     
                       
                         
                           
                             4 
                              
                             γ 
                           
                           + 
                           
                             
                               7 
                               2 
                             
                              
                             δ 
                           
                         
                         ≤ 
                         ϕ 
                         ≤ 
                         
                           
                             4 
                              
                             γ 
                           
                           + 
                           
                             4 
                              
                             δ 
                           
                         
                       
                     
                   
                 
                 S(φ) = 0 
               
               
                   
               
             
          
         
       
     
         [0060]    Diagrams p-V (pressure-volume) of two diesel engines are shown on  FIGS. 17   a  and  17   b . The first diagram on  FIG. 17   a  corresponds to a diesel engine, having a conventional crank mechanism, and the second diagram on  FIG. 17   b  corresponds to a cam law according to the invention. The effective operation of the cam engine is greater than that of traditional engine, due to the fact that in the case of cam engine the heat is brought into in almost constant cylinder volume, and its negative work for the change of the waste gases with fresh working medium is lower than that of traditional diesel engine, which again is due to the fact that around the dead centers and mostly in the bottom dead center, the pistons of the cam engine described may significantly reduce their velocity and even stop for a while. 
         [0061]      FIG. 18  shows engine composed of two modules  94 , and each module  94  is a two-cylinder four-stroke. The connection between the modules  94  is performed by outlet gearing  38 . 
         [0062]      FIG. 19  shows the connection between the cam law motion and the shaping of the cam curves. It is shown the geometry of treating cutter movement where each of 3D curves  97 , involved by the points of the axes  96  of the cutter, lie on the cylindrical surfaces  98 , which axes  99  coincide with the cam axis  100 . The curves  97  represent the piston law motion S(φ) depending on the angle of cam rotation. As a result of the above, each cam curve  97  will correspond to the curve of  FIG. 9 . 
         [0063]    Although the description above contains many specifics, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus, the scope of this invention should be determined by the appended claims and their legal equivalents.