VARIABLE INTERNAL COMBUSTION ENGINE CRANK

THE FIELD OF ART The invention relates to the field of mechanical engineering and more particularly to engineering matters and even more particularly to engineering systems or units and even more specifically to connections for rotation transmission. Specifically, it refers to a variable internal combustion engine crank whose the connecting rod rotation centre is changeable.

BACKGROUND OF THE INVENTION

The variable internal combustion engine crank disclosed in the present invention has not been disclosed in the prior art.

A motor or internal combustion engine is a heat engine in which both combustion and work production take place internally in the engine compartment. Thus, the conversion of the chemical energy of the fuel into thermal and consequently mechanical energy is achieved through combustion.

The kinematic mechanism of an internal combustion engine consists of the crank, the connecting rod and the piston. The crank is known to perform a purely rotational motion, the piston performs a purely linear (reciprocating) motion, and the connecting rod that connects the piston to the crank performs a complex motion i.e. the one end, which is connected to the piston, performs reciprocating motion and the other end, which is connected to the crank, performs rotational motion. The disadvantage of these machines is that the distance of the crank from the bearing point of the connecting rod remains constant so that the maximum torque is not achieved and an increased cylinder volume is required for a specific performance, while the crank consumes larger amounts of energy during exhaust and compression.

It is thus an object of the present invention to deal with the aforementioned disadvantages and shortcomings of the prior art by proposing a variable internal combustion engine crank.

It is a further object of the present invention to provide a variable internal combustion engine crank that produces more torque while achieving the same performance as a smaller cylinder volume engine.

It is a further object of the present invention to provide a variable internal combustion engine crank which achieves reduction of the combustion chamber at the moment of maximum expansion, while at the same time the crank is moved from the vertical to the maximum possible distance.

A further object of the invention is to disclose a variable internal combustion engine crank, which exhibits less resistance during exhaust and compression, where the crank consumes less energy since there is a shorter distance.

A further object of the invention is to provide a variable internal combustion engine crank, where the crankshaft fluctuates the distance from the bearing point of the connecting rod.

Another object of the invention is to present a variable internal combustion engine crank, where the pin is firmly connected to the rod.

It should further be noted that the camshaft and the internal combustion engine head system remain unchanged from those already known in the art.

These and other objects, features and advantages of the invention will become apparent in the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become apparent to those skilled in the art with reference to the accompanying drawings in which it is illustrated in an illustrative and non-limiting manner.

Figure 1 shows a sectional illustration of the variable crank, showing the shaft, the base, the pin, the piston and the connecting rod, among others.

Figure 2 shows in section the embossed path and the pin with the piston in full length, at the top dead centre. Figure 3 shows a section of the pin, the rod and the embossed path followed by the pin at the time when the piston starts to expand. Here the movement of the pin on the embossed path is obvious and therefore the change of the rotation point of the crank.

Figure 4 shows a section of the piston head at the bottom dead centre and at the same time the indicative position of the pin in the embossed path.

Figure 5 shows in section the time when the rod and the pin are perpendicular under the piston head and the piston remains at the bottom dead centre.

Figure 6 shows a section of the piston at the time the compression starts and the movement of the pin from the vertical to the embossed path is apparent, while the piston still remains at the bottom dead centre.

Figure 7 shows in section the termination of the piston head at the end of compression at the top dead centre and the indicative position on the embossed path where the pin is at that moment.

Figure 8 shows an exemplary illustration of a system with two pistons and rods, according to the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now to the accompanying drawings we will describe indicative embodiments of the variable internal combustion engine crank, as well as its mode of operation, in order to make obvious its general characteristics as well as its advantages.

The operation and the technical characteristics of the invention will be explained by reference to the operating phases of an engine. The system of the invention consists of a piston (1), Fig. 1, which moves inside a cylinder (2). The linear reciprocating motion of the piston (1) is converted to rotational one, by means of a suitable kinematic mechanism consisting of a connecting rod (3) and a crank (4), which is part of the crankshaft (5) of an engine. The crankshaft (5) is mounted via ball bearings (6) on bearings (7) being on both sides, while at the same time there is a base (8) which together with another base (9), on which the cylinder (2) rests, define the crank chamber. Contrary to what is known to date, the rod (3) is not connected to the crankshaft via a simple knob, but via a pin (10). The pin (10) is firmly connected, substantially anchored, to the rod (3), penetrating it, while at the same time penetrating the parts of the crank (4). At the same time, however, its two ends on either side enter an embossed path (11).

During the reciprocating motion of the piston (1), the rotational motion of the crankshaft (5) and the complex motion made by the rod (3), the pin (10) moves within the embossed travel (11), driving therein. Initially, in the first phase of operation, the piston (1), Fig. 2, is at the top dead centre and starts moving towards the bottom dead centre. The rotation of the crankshaft (5) and its connection to the rod (3) divert it from the vertical, Fig. 3, while the pin (10) moves within the embossed path (11). It becomes apparent that the point of rotation of the crankshaft (5) and the lower end of the rod (3) no longer coincide, as in conventional engines, but differ. To achieve this they are connected to each other with a connecting element (12), in a longitudinal hole (13), within which the pin (10) moves freely and in a straight line. In this way the movement of the piston (1) starts from the top dead centre to the bottom dead centre, while the rod (3) has diverted a few degrees from the vertical.

Similarly when the piston (1) reaches the bottom dead centre, Fig. 4, the pin (10) continues to move both in the embossed path (11) and inside the connection element (12), until the pin (10) also terminates its travel within the hole (13) of the connecting element (12), which occurs when the rod (3) is aligned vertically below the piston (1), Fig. 5. The compression phase of the fuel inside the combustion chamber begins with the shift of the rod (3), Fig. 6, with the movement of the pin (10) in the embossed path (11) and in the longitudinal hole (13) of the connecting element (12). The completion of the compression phase is achieved upon terminating the movement of the piston (1) at the top dead centre, Fig. 7, which occurs similarly again while the rod (3) is deflected a few degrees from the vertical. As becomes apparent, by changing the distance of the rotation centre of the crankshaft (5) from the rotation centre of the pin (10), it is possible during the piston (1) expansion and while increasing the distance of the rotation point of the crankshaft (5) to the centre of the pin (10) and while the piston (1) is near the top dead centre, to achieve rotation of the crank (4) a few degrees from the vertical, in order to utilize the greatest torque at the output of the crankshaft (5 ).

In an alternative embodiment of the invention, there is the possibility of connecting more than one variable crank in parallel, Fig. 8, where the crankshaft (5) of the one will be the same as the crankshaft (5) of the adjacent one so that each piston (1) works in complete harmony with the others. The two variable cranks are fixedly connected to each other by a spindle (14), which transmits motion from one crank to the other, via gears (15) on each side of each crank. In an alternative embodiment of the invention, sprockets or drive belts may be used instead of gears (15). The rest of the structure of each variable crank remains the same, according to what has been reported so far.

The materials used for both the pin (10) and the other components that make up the invention may be e.g. of titanium, without excluding the use of other materials, such as steel. It should be noted here that the description of the invention has been made with reference to illustrative examples, to which it is not limited. Therefore any change or modification in terms of shape, dimensions, morphology, materials used and construction and assembly components, as long as they are not a new inventive step and do not contribute to the technical development of the already known, are considered to be contained in the purposes and in the aspirations of the present invention.