Patent Publication Number: US-2012031383-A1

Title: Internal combustion engine

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an internal combustion engine with a crankshaft, at least one movable compression piston housed in a compression cylinder and at least one movable working piston housed in an operating cylinder, wherein the movement of the compression piston and the movement of the working piston are kinematically coupled to the movement of the crankshaft, so that, during a single revolution of the crankshaft by an intake stroke and a compression stroke of a four-stroke cycle, the compression piston moves back and forth and that the working piston moves back and forth during a single revolution of the crankshaft by a working stroke and an exhaust stroke of the same four-stroke cycle, wherein the compression cylinder has at least one inlet valve for drawing-in air into the compression cylinder with a downward movement of the compression piston and the working cylinder has at least one outlet valve for purging out combustion gases in an upward motion of the working piston. 
     2. Description of Related Art 
     As internal combustion engines for driving motor vehicles, machines and the like, at present, almost exclusively use reciprocating piston engines that operate on the Otto or Diesel principle. The deficiencies of these engines, including unsatisfactory efficiency, high emissions, especially during cold starts, considerable noise and the like are known and are largely attributed to the fact that the transformation of liquid fuel into the gaseous state, the mixture formation, ignition and combustion of all take place within a very small, short operating cycle under strongly varying and poor controllable flow conditions. 
     German document DE 602 25 451 T2 and corresponding U.S. Pat. Nos. 6,543,225 B2 and 6,609,371 B2 disclose a motor, which has a crankshaft that revolves around a crankshaft axis of the engine. In addition, a piston is provided which is housed within a first cylinder that can be moved and operatively connected to the crankshaft, so that the working piston moves back and forth during a single revolution of the crankshaft by a working stroke and an exhaust stroke of a four-stroke cycle. Also, a movable compression piston is provided which is housed within a second cylinder and operationally connected to the crankshaft, so that the compression piston moves back and forth during the same revolution of the crankshaft by an intake stroke and a compression stroke of the same four-stroke cycle. The first and second cylinders are connected to each other via a gas passage, wherein the gas passage contains an inlet valve and an outlet valve defining a pressure chamber in between, wherein the inlet valve and the outlet valve of the gas passage maintain essentially at least one specified ignition-state gas pressure in the pressure chamber during the entire four-stroke cycle. In order to reach the ignition position of the piston, the crankshaft must revolve at least by 20° from a position in which the working piston is located in its upper dead-point position. The ignition position is thus achieved only when the working piston is moving downward and has reached a specified distance from the upper dead center. The engine as known from prior art also has an unsatisfactory efficiency that is attributed to higher emissions. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide an internal combustion engine, which is distinguished from other engines as known from prior art by a higher efficiency, a good torque response, a low pollutant emission and low manufacturing and operating costs. 
     The aforementioned object is achieved in an internal combustion engine of the type mentioned above that has at least two combustion chambers that are separated from each other and interconnected with the compression cylinder and the working cylinder for igniting a fuel-air mixture, in accordance with a first alternative embodiment of the invention, by each combustion chamber being connected to the compression cylinder via at least one combustion chamber inlet valve and to the working cylinder via a combustion chamber outlet valve, and wherein the valves are so controlled that the outlet valve of the combustion chamber is opened only after combustion of the fuel-air mixture in the combustion chamber and that the combustion chambers are controlled alternately for combustion. 
     The invention relates to a reciprocating internal combustion engine, wherein the intake as well as the compression process is performed by at least one compression piston and the operating and pushing process of at least one working piston. The two pistons are arranged opposite each other. Between the working cylinder and the compression cylinder there is a connection via at least two combustion chambers located in the cylinder head, wherein the fuel-air mixture is brought to combustion, which can happen due to external or self-ignition (diesel fuel/biodiesel). The two combustion chambers are alternately activated only every second revolution, so that sufficient time is available for preparing the fuel and air mixture for combustion in the combustion chamber. Accordingly, the control of the valves is set, wherein upon combustion of a fuel-air mixture in the combustion chamber, the same combustion chamber is controlled only after a 720° revolution of the crankshaft and a fresh fuel-air mixture is burned in the combustion chamber again. The alternate combustion in at least two combustion chambers ensures a substantially complete combustion of the fuel-air mixture and contributes to low exhaust emissions. As a result, the internal combustion engine is distinguished by a higher efficiency than that of the engines as known from the prior art and the manufacturing and operating costs are low. 
     In principle, the combustion chambers can have an equal size. At least two pairs of combustion chambers can also be provided, each with two combustion chamber pairs of equal size, wherein the combustion chambers of a first combustion chambers pair can be larger than the combustion chamber pair of a second combustion chamber pair, and wherein both combustion chambers of a combustion chamber pair, i.e., equal-sized combustion chambers, are alternately controlled for combustion. At low speeds in city traffic, if the cylinders have a lower degree of filling, a combustion chamber pair can be controlled with smaller combustion chambers, and thus, the combustion efficiency can be increased. However, for faster travel, and maximum cylinder filling, the combustion chamber pair can be controlled with the larger combustion chambers. This can improve fuel utilization and ensures high combustion efficiency. The combustion takes place alternately in each case in the same size combustion chambers. 
     In another embodiment of the invention, it may be provided that at least two combustion chamber pairs are provided with two combustion chambers of different sizes, wherein each of the two combustion chambers of different sizes belonging to a combustion chamber pair can be controlled together for combustion and wherein the combustion chamber pairs are controlled alternately. Again, it is preferably such that the combustion chamber pairs each have equally large total combustion chamber volume, whereby the total combustion chamber volume comprises of the volumes of the combustion chambers of different sizes allotted to one pair of combustion chambers. The total volume of the larger combustion chamber and the smaller combustion chamber of a combustion chamber pair can be designed for a maximum cylinder filling. For example, one large and one small combustion chamber can form a pair of combustion chambers and are each controlled at the same time for combustion. In the next revolution of the crankshaft, a larger combustion chamber and a smaller combustion chamber of an additional combustion chamber pair are controlled for combustion. In this context, the larger combustion chamber can be approximately twice as large as the smaller combustion chamber. However, other proportions in size are possible in principle. 
     The control and/or opening and closing of the valves can be done electrically, pneumatically, mechanically or hydraulically. It can also be provided with automatic valves, actuated by the prevailing gas pressure in the cylinder, known as flapper valves. 
     The control of the valves can provide the opening of the combustion chamber outlet valve during revolution of the crankshaft by less than 20°, preferably less than 10°, especially less than 5°, via a position beyond that in which the working piston is located in its upper dead-point position. Preferably, the combustion chamber outlet valve is opened when the working piston is located directly in the upper dead center, with a deviation of ±1° to 4° with reference to the revolution of the crankshaft. When opening the outlet valve of the combustion chamber, the combustion of the fuel-air mixture is completed in the combustion chamber or essentially completed and the combustion process is concluded. The burned mixture is then passed through the opening of the combustion chamber outlet valve of the controlled combustion chamber into the working cylinder. 
     From the viewpoint of structural design, the kinematic coupling of the motion of compression piston and working piston to the crankshaft is preferably designed such that the compression piston and the working piston, in the case of a four stroke cycle, during the movement from the respective top dead center to the bottom dead center and back, execute a continuous counter-movement. In a preferred manner, the compression cylinder and the working cylinder side are arranged by side in a plane transverse to the longitudinal axis of the crankshaft, in particular perpendicular to the longitudinal axis of the crankshaft. This leads to a space-saving design of the engine and allows a kinematic coupling of the motion of compression piston and working piston with low friction losses, which will be discussed below. 
     In order to solve the above problem, it may be provided, in an internal combustion engine of in above mentioned type, in an alternative embodiment according to the invention, that the working piston is articulately connected with the crankshaft via a multi-part link rod, wherein the link rod has at least two connecting rods, and the connecting rods are connected at the end via at least one first hinge, while the other end of a first connecting rod of the link rod is flexibly connected with the working piston and the other end of a second connecting rod of the link rod is flexibly connected with the crankshaft, namely with a crank pin of the crankshaft, wherein a cross connecting rod is articulated at the end on the first hinge, wherein the cross connecting rod is type of a pivot rod that rotates about a pivot axis, wherein the other end of the cross connecting rod is flexibly connected via at least a second hinge with at least a third connecting rod, the third connecting rod being articulately connected with the compression piston. 
     Thanks to the proposed kinematic coupling of compression pistons, working pistons and crankshaft, the friction forces on the cylinder walls can be reduced in the upward and downward movement of the pistons, resulting in an improved power transmission to the crankshaft, and thus, to an increase in torque. By the division of the link rod under the working piston, an improved application of force is achieved in the revolution of the crankshaft, wherein the pressure across the working piston can be utilized almost without any loss of compression as a result of the connection of the working piston with the compression piston via the cross connecting rod. In the case of the noted articulated connection of the working piston and the compression piston with the crankshaft, less energy must be drawn from revolution so as to cause the compression via the compression piston. Here, the residual energy of the burned gases is further utilized in the working cylinder before the working piston reaches the bottom dead center, in order to move the compression piston upward. In the case of the engines as known from the prior art, this residual energy is lost with the compression of burned gas in the exhaust system. The aforesaid crank mechanism of the internal combustion engine contributes to a higher efficiency, better torque performance and lower emissions, coupled with low manufacturing and operating costs. 
     In another alternative embodiment of the internal combustion engine for solving the above-mentioned object, it may be provided that at least two separate compression chambers interconnecting the compression cylinder and the working cylinder are provided for the purpose of compressing air, or a fuel-air mixture, or for retaining the air compressed in the compression cylinder or for retaining a compressed fuel-air mixture, wherein the ignition and combustion of the fuel-air mixture can be carried out in the working cylinder, wherein each compression chamber is connected to the compression cylinder via at least one compression chamber inlet valve and wherein the at least one working cylinder and the valves are controlled such that the compression chambers are alternately controlled for compression. 
     This embodiment of the invention again relates to a reciprocating internal combustion engine, wherein the intake and compression process can be performed in a compression cylinder with a compression piston and the operating and compression process in an operating cylinder with piston. Preferably, the two cylinder-piston assemblies are arranged opposite each other, as has been described above. Between the compression cylinder and the working cylinder there exists a connection via at least two compression chambers located in the cylinder head, in which the drawn-in air through the compression piston is pushed during the compression stroke. In the compression chamber, the air may be treated as a gas mixture for combustion, or only when it has been “discharged” in the working cylinder, via the working piston. It is first ignited only in the working cylinder, depending upon the fuel by self-ignition or external ignition. The internal combustion engine with two compression chambers leads to a higher efficiency in fuel combustion, to a better torque performance and to a reduced emission of polluting substances, combined with low production and operating costs. 
     In a further preferred embodiment, the control of the valves can provide for the opening of the compression chamber outlet valve during revolution of the crankshaft by more than 340° to 360°, preferably provide more than 350° to 360°, preferably more than 355° to 360°, wherein the working piston is located in its upper dead-point position during revolution of the crankshaft by 360°. Preferably, the introduction of compressed air and/or compressed air-fuel mixture is done immediately before the working piston has reached its top dead center point. The introduction of pressure from a compression chamber in the working cylinder starts before reaching a 360° crankshaft revolution. The compression chamber outlet valve closes, preferably before it comes to ignition and combustion of the fuel-air mixture in the working cylinder. It is essential that the two compression chambers are controlled alternately, i.e., at every second turn, thus it has been described above in connection with said embodiment of an internal combustion engine with two combustion chambers. 
     The compression chambers may be of equal size. There may also be at least two different compression chamber pairs, each with two compression chambers of equal size, wherein the compression chambers of a first compression chamber pair are greater than the compression chambers of a second compression chamber pair and in each case the same two compression chambers of a compression chamber pair can be controlled alternately for compression. It is also possible that at least two compression chamber pairs are provided, each with at least two compression chambers of different size, wherein each of the two different sized compression chambers of a compression chamber pair can be controlled together for compression and wherein the compression chamber pairs are controlled alternately. 
     The temperature of combustion air and/or fuel-air mixture can be favorably influenced using water, distilled water or mixtures thereof, together with alcohol and if necessary, other components. In this context, a fourth alternative embodiment of the invention for solving the object mentioned is provided with at least one device for injecting water and/or distilled water and/or alcohol and/or a mixture of water and alcohol and if necessary, other substances into the compression cylinder and/or into a combustion chamber interconnecting the working cylinder and the compression cylinder and/or into a compression chamber interconnecting the working cylinder and the compression cylinder and/or an intake of the compression cylinder. Due to the provision of a sufficiently high water content in the fuel-air mixturem self-ignition can be precluded during compression of the gas mixture. 
     Another aspect of the invention relates to a method for operating an internal combustion engine of the type described above based on the method steps as illustrated in the drawings. 
     The aforementioned aspects and features of the present invention and the aspects described in the following and the features of the present invention can be used independently, and also in any combination. 
     Further advantages, features, characteristics and aspects of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic cross-sectional view of a first embodiment of an inventive internal combustion engine with two combustion chambers, with valves of the combustion chambers are arranged essentially parallel to the cylinder axes, 
         FIG. 2  is a schematic top plan view of a second embodiment of an internal combustion engine with four combustion chambers, wherein the valves of the combustion chambers are arranged essentially perpendicular to the cylinder axis, 
         FIGS. 3   a  to  3   f  are schematic representations of the four-stroke cycle internal combustion engine as shown in  FIG. 1  during operation of the internal combustion engine, 
         FIG. 4  is a schematic cross-sectional view of a third embodiment of an internal combustion engine with two compression chambers, wherein the valves of the compression chambers are arranged essentially parallel to the cylinder axes, 
         FIG. 5  is a schematic top plan view of a fourth embodiment of an internal combustion engine with two compression chambers, wherein the valves of the compression chambers are arranged essentially perpendicular to the cylinder axis, 
         FIG. 6  is a schematic cross-sectional view of a fifth embodiment of an internal combustion engine with two compression chambers and at least one combustion chamber in the working piston, 
         FIG. 7  is a schematic cross-sectional view of a sixth embodiment of an internal combustion engine with two compression chambers and having at least one combustion chamber in the working piston, and 
         FIGS. 8 to 10  are perspective views of further embodiments of an internal combustion engine, wherein the working piston is flexibly attached to the crankshaft via a multi-part link rod. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows an internal combustion engine  1  in a schematic cross-sectional view. The internal combustion engine  1  has a crankshaft, which is not shown in detail. However, the longitudinal axis  2  of the crankshaft is shown, by which a crank arm  3  revolves during operation of internal combustion engine  1 . The internal combustion engine  1  has a compression pistons  5  that can be freely moved in an operating cylinder  6  and a working piston  7  that can be freely moved in a compression cylinder  4 , wherein the movement of the compression piston  5  and the movement of the working piston  7  are kinematically coupled to the movement of the crankshaft so that the compression piston  5  moves back and forth during a single revolution of the crankshaft in an intake stroke and a compression stroke of a four-stroke cycle and the working piston  7  moves back and forth during a single revolution of the crankshaft in an operating stroke and an exhaust stroke of the same four-stroke cycle. The compression cylinder  4  has at least two inlet valves  8  for drawing-in air into the compression cylinder  4  during a downward movement of the compression piston and the working cylinder  7 , and two outlet valves  9  for emitting combustion gases from the working cylinder  6  during an upward movement of the working piston  7 . The inlet valves  8  and the outlet valves  9  are arranged perpendicular to the cylinder axis of compression cylinder  4  and the working cylinder  6 . 
     In order to obtain adequate time for preparation of a fuel-air mixture and combustion of the fuel-air mixture, at least two, preferably four, separated from one another, combustion chambers  10 - 13  having the compression cylinder  4  interconnected with the working cylinder  6  are provided for ignition and combustion of fuel-air mixture. This is illustrated in  FIGS. 1 to 3 . Each of the combustion chambers  10 - 13  is connected via at least one combustion chamber inlet valve  14   a - 14   d  with the compression cylinder  4  and is also connected with the working cylinder  6  via at least one combustion chamber outlet valve  15   a - 15   d . The valves  8 ,  9 ,  14   a - 14   d,    15   a - 15   d  are controlled such that the combustion chamber outlet valve  15   a - 5   d  of a combustion chamber  10 - 13  is opened only after the combustion of the fuel-air mixture in combustion chambers  10 - 13  and that the combustion chambers  10 - 13  are alternately controlled for combustion. Thus, essentially complete combustion of the fuel in the combustion chambers  10 - 13  is guaranteed, resulting in a higher efficiency and a low-emission of pollutants from the internal combustion engine  1 .  FIG. 1  shows only one combustion chamber  10  with a combustion chamber inlet valve  14   a  and a chamber outlet valve  15   a.  The combustion chamber valves  14   a,    15   a  are arranged parallel to the longitudinal axes of the compression cylinder  4  and the working cylinder  6 . 
       FIG. 2  shows a second embodiment of an internal combustion engine  1  having four combustion chambers  10 - 13 , wherein the combustion chamber inlet valves  14   a - 14   d , and the combustion chamber outlet valves  15   a - 15   d  are arranged perpendicular to the longitudinal axis of the compression cylinder  4 , and perpendicular to the longitudinal axis of the working cylinder  6 . In doing so, the combustion of the fuel in the combustion chambers  10 - 13  is least disturbed by the valves  14   a - 14   d,    15   a - 15   d.  However, basically, it is also possible that the combustion chamber inlet valves  14   a - 14   d  and/or the combustion chamber outlet valves  15   a - 15   d  are arranged parallel to the longitudinal axis of the compression cylinder  4  and/or to the longitudinal axis of the working cylinder  6  as represented in  FIG. 1 . 
     As is evident from  FIG. 2 , the combustion chambers  10  and  13  have a larger combustion chamber volume than the combustion chambers  11  and  12 . At low speed in city traffic, when the cylinders have a lower degree of filling, the smaller combustion chambers  11 ,  12  are controlled alternately, thereby increasing the efficiency of combustion. However, for maximum cylinder filling, the larger combustion chambers  10 ,  13  are controlled alternately. In principle, it is also possible that the size of the combustion chambers  10 - 13  is so chosen that the combustion chamber volume of the larger combustion chambers  10 ,  13 , is approximately twice as large as the volume of the smaller combustion chambers  11 ,  12 . The total combustion chamber volume of a larger combustion chamber  10 ,  13  and a smaller combustion chamber  11 ,  12  may then be sufficient for a maximum cylinder filling. Then, for example, the combustion chambers  10  and  11  and the combustion chambers  12  and  13  can be actuated simultaneously. It is understood that the invention is not restricted to the proportions in size as shown in  FIG. 2 . 
     The functioning of the internal combustion engine  1  is described in detail in the following. Air is drawn-in through the open inlet valve  8  during the downward movement of the compression piston  5  in the compression cylinder  4 . Inlet valves  8  close at the bottom dead center of the compression piston  5  and the combustion chamber inlet valve  14   a  of the first combustion chamber  10  opens. This is shown schematically in  FIGS. 3   a  and  3   b.    
     During upward movement of the compression piston  5  (see,  FIGS. 3   c - 3   f ), the drawn-in air is compressed in the first combustion chamber  10 , at which the combustion chamber outlet valve  15   a  is closed first. Upon the compression piston  5  reaching upper dead center, the first combustion chamber inlet valve  14   a  of the combustion chamber  10  closes. 
     If diesel or bio diesel is used as fuel, then air is prepared for combustion, wherein fuel is injected through a nozzle  16  into the combustion chamber  10 , and brought to combustion through auto-ignition. If gasoline, gas, hydrogen or alcohol is used as fuel, air is pre-treated for combustion with direct injection through the nozzle  16  and then brought to combustion in the combustion chamber  10  by spark ignition using a spark plug (not shown here). If gasoline, gas, hydrogen or alcohol is used as fuel, the enrichment of air can also happen in a suction pipe or an intake channel  17  of the cylinder head. Subsequently, the compressed mixture in the combustion chamber  10  is combusted by means of spark-ignition using a spark plug. Enrichment of combustion air with fuel in the compression cylinder  4  can be done through a nozzle  18 . Finally the compressed mixture in the combustion chamber  10  is brought to combustion by means of spark ignition. The air can be partially enriched in the suction pipe or in the inlet channel  17  in the cylinder head, in the compression cylinder  4  through the nozzle  18  and/or in the combustion chamber  10  through the nozzle  16 . It is understood that other combustion chambers  11 ,  12 ,  13  can have corresponding nozzles  16 . Then, the compressed-air mixture fuel contained in the combustion chamber  10  is brought to combustion by means of spark ignition. 
     Once the compression piston  5  reaches upper dead center, the working piston  7  is located at bottom dead center (ref.  FIG. 3   f ), which means that the combustion chamber outlet valve  15   a  of the first combustion chamber  10  closes. Thereafter, the working piston  7  compresses the stress-relieved, burned mixture through the open outlet valve  9  from the working cylinder  6  through the outlet channel  19  of the cylinder head in the exhaust. 
     At the same time, the compression piston  4  is on its way to bottom dead center. Air is drawn-in through the open inlet valves  8 . Once the working piston  7  reaches upper dead center, the outlet valves  9  are closed and the combusted mixture in the first combustion chamber  10  is led into working cylinder  6  through the opening of the first outlet valve  15   a  of the combustion chamber. 
     About the same time, the inlet valves  8  close, the second combustion-chamber inlet valve  14   b  of the second equal-sized combustion chamber  13  is opened and the previously drawn-in air or the fuel-air mixture is now compressed in the combustion chamber  13  on the path of the compression piston  5  from the bottom dead center to top dead center. Subsequently, as described above, the same takes place with respect to the combustion chamber  13 . Here, the working piston  7  is located on the path from the top dead center to bottom dead center. At bottom dead center, the first chamber outlet valve  15   a  closes and the outlet valves  9  open, wherein the compression piston  5  is located approximately at the top dead center. Thereafter, the second chamber inlet valve  14   b  closes and the inlet valves  8  open. 
     As per  FIG. 1 , the compression cylinder  4  and the working cylinder  6  are arranged alongside one another in a plane perpendicular to the longitudinal axis  2  of the crankshaft. 
     As can be seen from  FIG. 1 , the working piston  5  is articulately connected with the crankshaft via a multi-part link rod  20 , wherein the link connecting rod  20  has at least two connecting rods  21 ,  22 , wherein the connecting rods  21 ,  22  are connected at their proximal ends via at least a first hinge  23 , wherein the opposite end of the first connecting rod  21  of the link connecting rod  20  is pivotably connected with the working piston  7  and the other end of the second connecting rod  22  is pivotably connected to a crank arm  3  of the crankshaft. At the first hinge  23 , an end of a cross connecting rod  24  is pivotably connected, wherein the cross connecting rod  24  a type of a rocker arm that pivots about a pivot axis  25 . The cross connecting rod  24  does not necessarily have a straight shape. The other end of cross connecting rod  24  is pivotably connected via at least one second hinge  26  to at least a third connecting rod  27  which is pivotably connected to the compression piston  5 . The illustrated form of the kinematic coupling of the compression piston  5 , working piston  7  and crankshaft causes the compression piston  5  and the working piston  7  to move in opposite directions during the four-stroke cycle. Thanks to the connection via link connecting rod  20  and cross connecting rod  24 , the compression piston  5  and the working piston  7  can be moved up and down with lower friction losses, leading to an increase in overall efficiency in fuel combustion. 
     It is also shown in  FIG. 1 , that the longitudinal axis  2  of the crankshaft is arranged below the rotational axis of the first hinge  23  and below the rotational axis of the second hinge  26 . Further, the longitudinal axis  2  of the crankshaft can run below the axis of rotation  25  of the cross connecting rod  24 . The longitudinal axis  2  of the crankshaft is spaced apart in a horizontal direction laterally from the rotational axis of the first hinge  23  and, preferably, arranged in the area between the pivotal axes of the first hinge  23  and the second hinge  26 . This structure leads to very low friction losses, and thus, to a high degree of energy utilization during fuel combustion. In addition, it is preferably provided that the longitudinal axis  2  of the crankshaft runs in a horizontal direction in the region between the rotational axis  25  of the cross connecting rod  24  and the axis of revolution of the first hinge  23 . In the horizontal direction, the longitudinal axis of the crankshaft  2  is suitably spaced apart from the central axis of the working piston  7 . 
     The connecting rods  21 ,  27 , respectively, are anchored in the area of the central longitudinal axis of the working piston  7  and/or the compression piston  5 . The rotational axis  25  of the cross connecting rod  24  is located in vertical direction between the rotational axis of the first hinge  23  and the rotational axis of the second hinge  26 . 
     Schematically, it can be seen that an eccentric mounting of cross connecting rod  24  can be provided so as to facilitate the movement of the working piston  5 ,  7  with very little frictional in the cylinders  4 ,  6 . The eccentric arrangement of bearings has an impact on the position of the two connecting rods  21 ,  27 , which are hinged to the pistons  5 ,  7  or the bearing can be moved in its position by means of a servo-motor. The cross connecting rod  24  can be mounted eccentrically on a rotating shaft. It is also possible that widely spaced apart positions are specified, where the cross connecting rod  24  can be mounted centrally or eccentrically. The bearing fixed on the axis of revolution  25  of the cross connecting rod  24  can be arranged on a bolt, a stepwise adjustable bolt or a revolving shaft, which can also be mounted eccentrically. 
     According to  FIG. 1 , the cylinders  5 ,  7  can be arranged inclined to the vertical motor axis. Here, a positive or negative slope of the motor axis can be present. Basically, the cylinders  5 ,  7  can also be arranged parallel to one another. 
     With reference to  FIG. 1 , the compression piston  5  can be arranged on the right side of the working piston  7 , in the same arrangement of the longitudinal axis  2  of the crankshaft  2 . In principle, other arrangements of pistons to crankshaft  5 ,  7  are beneficial and possible. 
     Incidentally, the link rod  20  may also be formed of more than two connecting rods  21 ,  22 . More connecting rods can be provided so as to reach a desired reduction of friction losses during upward and downward movement of the piston  5 ,  7  inside the cylinders  4 ,  6 . 
     The compression cylinder  4  and the working cylinder  6  can be of different cylinder volumes with respect to the cylinder volume between the top dead center and bottom dead center of the compression piston  5  and/or the working piston  7 . Here, the same or different cylinder geometries are possible. For example, pistons  5 ,  7  can be combined with a round cross-sectional shape with pistons  5 ,  7  with an oval cross-sectional shape. The illustrated internal combustion engine  1  can be operated with turbo-charging or supercharging. 
     A change in cylinder volume can also be reached by a change in the length of cross connecting rod  24  or the arrangement of the axis of revolution  25  of the  24  cross connecting rod, which results in a change of the compression stroke of the working piston  5 . 
     In a certain symmetrical arrangement of the working pistons  5 ,  7 , and the arrangements of longitudinal axis  2  of the crankshaft and the axis of revolution  25  of the cross connecting rod  24  (not shown), it is possible, in principle, to link a further connecting rod, which is not shown in detail, to the crank arm  3 , on the one hand, and to the second hinge  26 , on the other. This would facilitate a connection between the crankshaft, the cross connecting rod  24  and the third connecting rod  27 . The other rod must not be anchored on the same crank pin like the connecting rod  22 . 
     The length ratios of the connecting rods  21 ,  22  and  27  and of the cross connecting rod  24  are not limited to the ratios as shown in  FIG. 1 . 
       FIGS. 4 to 6  show alternate embodiments of internal combustion engines  28 , wherein the components matching the internal combustion engine  1 , as shown and described in  FIGS. 1 to 3 , have been provided with the same reference characters. Only the differences between internal combustion engines  1  and  28  are described in the following. 
     The internal combustion engine  28  has, in the place of combustion chambers, at least two compression chambers  29 ,  30  separated from each other and interconnecting the compression cylinder  4  and the working cylinder  6 , which according to  FIG. 5  can have the same volumes. The compression chambers  29 ,  30  are provided for compressing of air, or for compressing a fuel-air mixture, wherein the ignition and combustion of the fuel-air mixture can take place in the embodiment of the working cylinder  6  as shown in  FIG. 4 . 
     Each compression chamber  29 ,  30  is connected via at least one compression chamber inlet valve  31   a ,  31   b  with the compression cylinder  4  and via at least one compression chamber outlet valve  32   a,    32   b  with the working cylinder  6 . The valves  8 ,  31   a ,  31   b,    32   a,    32   b,    9  are controlled such that the compression chambers  29 ,  30  are alternately actuated for compression. In the case of the internal combustion engines  28  as shown in  FIGS. 4 and 6 , the valves  8 ,  31   a,    31   b,    32   a,    32   b,    9  are arranged essentially parallel to the longitudinal axis of the working cylinder  4  and/or the compression cylinder  6 . In the embodiment shown in  FIG. 5 , the compression chamber inlet valves  31   a,    31   b  and the compression chamber outlet valves  32   a,    32   b  are arranged perpendicular to the longitudinal axis of each cylinder. Further it is understood that in principle, more than two compression chambers  29 ,  30  may be provided. The compression chambers can be of different sizes, as illustrated for the combustion chambers  10 - 13  in  FIG. 2 . 
     The functioning of the internal combustion engine  28  as shown in  FIG. 4 ,  28  is described below. Air is drawn-in through the open inlet valve  8  during downward movement of the compression piston  5  in the compression cylinder  4 . At the bottom dead center of the compression piston  5 , the inlet valves  8  close and the compression chamber inlet valve  31   a  of the first compression chamber  29  opens. During an upward movement of the compression piston  5 , the air drawn in the first compression chamber  29  is compressed, in which the compression chamber outlet valve  32   a  is closed. When the compression piston  5  reaches the top dead center, the first compression chamber inlet valve  31   a  closes. The working piston  7  about now starts travelling to the top and pushes the stress-relieved gases from the open outlet valves  9  through the outlet valve channel  19  in the exhaust. 
     The compression piston  5  now again reaches approximately bottom dead center in the compression cylinder  4  and the air is drawn-in through the open inlet valve  8 . The working piston  7  is now located close to a position at 360° of the crankshaft revolution. 
     If diesel or bio-diesel is used as fuel, then the compressed air is prepared for combustion, in which the fuel from the first compression chamber  29  is introduced into the working cylinder  6  through the now open outlet valve  32   a  of the compression chamber. After closing the compression chamber outlet valve  32   a,  fuel is injected. Thanks to the high pressure, fuel in the cylinder  6  is brought to combustion by self-ignition. If gasoline, gas, hydrogen or alcohol is used as fuel, then the air for combustion is prepared by direct injection, by guiding it through the open outlet valve  32   a  of the compression chamber into the working cylinder  6 . After closing the compression chamber outlet valve  32   a,  fuel is injected through a nozzle  33  and then brought to combustion with a spark plug  34 . 
     Enriching the air can also be performed in the suction pipe or the intake port  17  of the cylinder head. Upon enrichment, the compressed mixture present in the first compression chamber  29  is introduced through the open outlet valve  32   a  of the compression chamber into the working cylinder  6  and brought to combustion after closing the compression chamber outlet valve  32   a  by means of ignition spark plug  34 . Air can also be enriched in the compression cylinder through the nozzle  18 . Thereafter, the compressed mixture present in the compression chamber  29  is again passed through the open outlet valve  32   a  of the compression chamber into the working cylinder  6 , and brought to combustion by means of spark ignition upon closing the compression chamber outlet valve  32   a.  Finally, the enrichment of air can take place partly in the suction pipe or inlet channel  17  in the cylinder head, in the compression cylinder  4  through the nozzle  18  and/or in the compression chamber  29  through the nozzle  16 . It is understood that the second compression chamber  30  can have a corresponding nozzle  16 . Thereafter, the compressed mixture present in the first the compression chamber  29  is passed through the open outlet valve  32   a  of the compression chamber into the working cylinder  6  and brought to combustion by means of spark ignition upon closing the compression chamber outlet valve  32   a.    
     Post ignition, working piston  7  is moved back downward and presses the compression piston  5  located in the compression cylinder  4  upwards by means of cross connecting rods  24 . The compression piston  5  pushes the air through the open compression chamber inlet valve  31   b  into the second compression chamber  30 . 
     Once the compression piston  5  has reached the top dead center, the working piston  7  is located in the bottom dead center, which means that the combustion chamber outlet valve  32   a  closes. Thereafter, the working piston  7  compresses the stress-relieved, burned mixture through the open outlet valve  9  through the outlet valve channel  19  of the cylinder head into the exhaust. At the same time, the compression piston  5  moves to the bottom dead center and draws-in air through the open inlet valves  8 . When the working piston  7  reaches a crankshaft revolution just before the notch at 360°, the outlet valves  9  are closed and the pressure present in the second compression chamber  30  is passed through the compression chamber outlet valve  32   b  in the working cylinder  6  above the working piston  7 . Now, as before, it is processed as described further, with reference to the second compression chamber  30 . 
     When using diesel or bio-oil as fuel, optionally, valves  31   a,    31   b,    32   a,    32   b  of the compression chambers  29 ,  30  are arranged essentially perpendicular to the respective cylinder axis. 
     In the internal combustion engine  28  shown in  FIG. 6 , a vase-shaped combustion chamber  35  is preferably provided in the working piston  7 . The combustion chamber  35  is so arranged in the working piston  7  and has a cross-sectional geometry such that air emanating from the combustion of fuel from the respective compression chamber  29 ,  30  is guided to the combustion chamber  35  such that a rotational flow and/or a swirl of the incoming air is formed, thereafter fuel is injected in its middle range. This requires an appropriate geometry of the combustion chamber  35 , which is preferably formed in the shape of a vase as shown in the illustrated embodiment. From the respective compression chamber  29 ,  30 , the outgoing air meets the inner wall  36  of the combustion chamber  35  and is deflected thereby, so that there is a revolving wall flow in the combustion chamber  35 . It results in a directed emission of air from the respective compression chamber  29 ,  30  toward the inner side wall surfaces of the combustion chamber  35  in the upper region of the sidewall surfaces. It is understood that deviating from the embodiment as shown schematically in  FIG. 6 , the outlet valve of each compression chamber  29 ,  30  can be aligned to the combustion chamber  35  and can have a suitably adapted outlet geometry. 
     In the combustion chamber  35  of the working piston  7 , still hot residual gases are found after combustion of the fuel and compression of the burned gases. During subsequent inflow of fresh gases from the respective compression chamber  29 ,  30  for the next combustion process, these residual gases are cooled. This cooling is slowed down by the formation of a rotational flow at the inner wall  36  of the combustion chamber  35 . Especially when operating the internal combustion engine  28  with diesel fuel, the colder air-gas mass, not required for combustion, is compressed by the rotational flow formed outside and thus prevent a rapid cooling of the gases and/or the burned mixture at the working piston  7 . The colder air-gas mass, not required for combustion, form on the inner wall  36  of the combustion chamber  35  an air cushion that acts as insulation. Thus, pressure reduction in the working cylinder  6  is reduced. It is understood that the combustion chamber  35  is only schematically shown in  FIG. 6 . The combustion chamber  35  can be arranged further adjacent to the outlet valve of the compression chamber  29 ,  30 . In principle, the combustion chamber  35  may also have a further cross-sectional shape, which favors the formation of a rotational flow at the inner wall  36  of the combustion chamber  35 . Further, a plurality of combustion chambers  35  can be provided, wherein each combustion chamber  35  is spatially assigned a certain compression chamber  29 ,  30 . 
       FIG. 7  shows a fifth embodiment of an internal combustion engine  28 , which essentially corresponds to the embodiment shown in  FIG. 6 , but in mirrored arrangement of compression piston  5  and working piston  7 , which necessitates a different arrangement of the connecting rods for kinematic coupling of the working pistons  5 ,  7 . 
       FIGS. 8 to 10  show further embodiments of internal combustion engines  28 , wherein the working piston  7  is connected via a hinge to a multi-part link rod  20  with the crankshaft. The link rod  20  has in turn two connecting rods  21 ,  22 , wherein the connecting rods  21 ,  22  are connected together at their ends by at least one first hinge (pivot pin)  23 . The other end of a first connecting rod  21  is pivotably connected to the working piston  7  and the other end of a second connecting rod  22  is pivotably connected with two pivot pins  37 , which receive the second connecting rod  22  and during operation, describe a circular path around the rotational axis of the crankshaft. The pivot pins  37  are connected to a shaft journal  38  of the crankshaft. 
     In the area of the first hinge  23 ,  FIG. 8  shows two connecting rods  39 ,  40  that are parallel, but spaced apart from each other and pivotably connected at their ends to the connecting rods  21 ,  22 . The connecting rods  39 ,  40  are swivel-mounted in the form of a rocker about a rotational axis  25 . In the case of the embodiments as shown in  FIGS. 8 and 9 , the connecting rods  39 ,  40  form a cross connecting rod, through which, the movements of the working piston  7  and compression pistons  5  are coupled. 
     At the other end, each connecting rod  39 ,  40  is connected via at least one second hinge  26  with a third connecting rod  27 . The third connecting rod  27  is pivotably connected to the compression piston  5 . 
     As is clear from  FIGS. 8 and 9 , the distance between the connecting rods  39 ,  40  are chosen to be large so that a back-swing of the crank pins  37  is possible. Thus, the revolution axis  25  can be arranged closer to the rotational axis of the crankshaft, which has a beneficial effect on the efficiency of fuel combustion and restricts a lower overall height. 
     In the embodiment shown in  FIG. 9 , the second connecting rod  22  is connected via a second pivot joint  41  with the connecting rods  39 ,  40 . The first connecting rod  21  is connected via the first pivot joint  23  with the connecting rods  39 ,  40 . The connecting rods  21 ,  22  need not, therefore, be connected via a hinge joint with the cross connecting rod, which can also apply to the above-described embodiments of internal combustion engines  1 ,  28 . 
     In the embodiment shown in  FIG. 10 , the cross connecting rod  24  has a first rocker arm  42  pivotably connected with a third connecting rod  27 , which pivots about the rotational axis  25 . At the other end, the cross connecting rod  24  has two mutually parallel flanks  43 ,  44 , which receive both of the connecting rods  21 ,  22  and are hinged to the connecting rods  21 ,  22 .