CA3138257A1 - Synchronous two-stroke "servo piston" service unit with floating ring for endothermic engines - Google Patents

Abstract

The SERVO-PISTON propulsor aims to improve the energy output efficiency generated within the engine, it operates individually as it does not require further devices, it distinguishes itself by its ability to develop a new kinematic process thanks to a new stroke called "scission", which basically divides the device into two sections: the central section, with a central disc connected to the rod, that drags the external one shaped like a "floating ring". It does not require additive oil in the fuel, it provides low consumption even if compared to the four-stroke engines as it is not subordinated to any type of valves, which absorb power, complicate the functioning, raise temperatures and oblige the employment of specific antiknock petrols. With such specifications one gets the benefit to employ a sole thermodynamic cycle for the complete turn of the camshaft, therefore this efficiency makes it a two-stroke system.

Description

TITLE: SYNCHRONOUS TWO-STROKE "SERVO PISTON" SERVICE UNIT WITH FLOATING
RING FOR ENDOTHERMIC ENGINES
Technology field which the invention refers to The mobility and the intended use of the unit presented is aimed at all those vehicles equipped with internal combustion engines in a condition of what can be moved in relation to space-time movement. It is employed for transportation in general, for leisure, for work and for sports competitions, in relation to people or things.
The state of the art and the preexisting technology of the two-stroke engine The age of the two-stroke engine, as is well known, is slowly drawing to an end, abandoned by the majority of the motor industry despite the capacity that this system is still be able to express and despite it appearing to be still valid from the point of view of versatility, compactness and constructive simplicity, which dictated a low-cost production and sale. However, a strong use still remains in environments in which environmental regulations are less restrictive, for instance for motocross competitions in the mountains, for boats in the nautical field and for snowmobiles on the snow but, as for road use, nowadays it has been abandoned even for motorcycles.
Date recue/date received 2021-10-27

2 The state of the art and the preexisting technology of the four-stroke engine The demand for increasingly efficient and clean engines and the economic and sports competition have led the evolution of this type of engine to high levels, especially for the exasperated use of the turbo compressor which, although it brings benefits at a functional level, cannot be said to be also successful in containing polluting emissions. As a matter of fact turbo engines, by exploiting the exhaust gas pressure, decrease the ability of gases to be filtered. And it is logic to think that this matter has come to a climax and that further developments in that direction will gradually decline given the advance of electric battery-powered propulsors.
Technical problem with the two-stroke engine The reasons for the decline of the two-stroke engine are: the severe anti-pollution regulations in force in the cities and in the inhabited centers, high consumption and the burden of adding oil to the fuel.
Recently, there have been patents attempting to address the inefficiencies of the two-stroke engines by employing counter pistons, which oppose each other with complex mechanisms in order to set into motion the relating laborious devices which, in order to function, require unique systems built on purpose like: crankshafts in series, articulated joints, rotating valves, pipe supports with sliding rods, connecting rods, double arm with variable geometry movements, separated prechambers, high-pressure supply systems and dedicated turbo compressors.
Date recue/date received 2021-10-27

3 The solutions are different from each other but they need to be suitably manufactured and employed in engines specifically constructed for the purpose. All of these patented sophistications are not easy to implement due to the complexity of the mechanisms to be produced, to the design and production costs and to the practical and economical benefits, and probably they are even far from the creators' intentions.
Technical problem with the four-stroke engines A symptomatic factor that slows down the evolution of the four-stroke engine is certainly determined by the mushroom valves which, though still indispensable, at the same time set limits due to their inefficient function; they absorb part of the energy produced and waste heavy amounts of fuel for their own cooling at higher speeds and result in further waste during the so-called "crossover" phase. They exclusively work with specific fuels with a higher octane rating as a consequence of the auto ignition caused by high working temperatures.
Description of invention - The synchronous two-stroke "servo piston"
service unit with floating ring (1) proposes the employment of a two-stroke propulsion system for endothermic engines by exploiting the full power that the system possesses. This new technology is sustainable, it complies with the strict regulations in force and it is accessible in large scale with low-cost design and production thanks to the extreme simplicity of construction and to the great benefits offered. The invention, unlike its two-stroke direct competitors which propose similar systems in the light of the actual state of the art, presents itself with Date recue/date received 2021-10-27

4 very simplified mechanics of movement, it is compatible with the current technology of distribution employed in modern four-stroke engines and it uses the same components, but larger and heavier. But what is even more innovative, which makes it different from other systems, is the way the fresh charge (air/fuel mixture) is introduced into the cylinder, in fact this new system provides for the inflow of the fresh charge through a lamellar valve located at the top of the cylinder chamber (2/3) which, thanks to the depression generated by the servo piston moving downwards from the TDC to the BDC during the suction stroke, introduces directly the mixture thus filling up the cylinder chamber completely (2/5). Once the mixture has been preloaded and pressurized, the servo piston moves back up from the bottom dead center and the scission stroke occurs, that is to say that the servo piston decomposes into two sections, the external ring separates from the central disc in traction which is braked by the friction generated by the compression rings coming into contact with the cylinder wall (2/6). In this circumstance, once the cylinder chamber depressurizes, the servo piston is able to move back up to the TDC through the fresh charge previously sucked up and to pour the latter downwards from the upper part of the cylinder itself (2/7-8), thus turning the preload into the fresh charge, and then it reassembles as one element at the end of stroke forming the top of the cylinder head (2/9).
Unlike the modern four-stroke engines, the advantages of this system lie in the fact of being able to use more ecological and alternative fuels benefiting from the absence of the overhead mushroom outlet valve which Date recue/date received 2021-10-27 considerably overheats to the passage of the exhaust burnt gases.
Moreover additional benefits are derived during the gas exhaust stroke which takes place from the lower point of the cylinder (2/5), in fact exhaust gases remain less time in the cylinder chamber and, once they have expanded after the detonation, they directly flow out in only one stroke as they are no longer pushed back up to the outlet valve, which avoids the resulting overheating of the head due to heat radiation and, as a consequence, having to use specific antiknock fuels with a higher octane rating. Thanks to the cold head (less hot) one profits from a higher compression ratio with a resulting better thermal efficiency in comparison to the current combustion engines in which only about a third of the energy developed during the combustion of the air-fuel mixture is transformed into mechanical energy, the rest of it ends up unused, wasted in the outlet or transferred to the cooling system. At last, a further benefit one can get from the servo piston is that the turbo compressor is not employed, in fact the exasperated use of the latter in modern four-stroke engines in order to increase the power leads to a reduced ability to catalyze discharges due to the pressure drop and to the substantial increases in size and costs.
THREE-STROKE SYSTEM - The system architecture has been designed on the basis of the S/P's peculiarity, which is to carry out two simultaneous activities (plus an extra one) out of the four functional thermodynamic strokes of the Otto cycle named "service strokes", which comprise the fresh mixture suction stroke simultaneously combined with the burnt gas(2/3-4-5) exhaust stroke and an extra one called "scission", hereafter Date recue/date received 2021-10-27 explained. The remaining strokes, those of compression and expansion called "active", are dependent on the power unit represented by the principal piston.
PROPULSION FUNCTION - The work carried out by the S/P in the cylinder chamber is comparable to that of a plunger turned upside down which moves in a rectilinear reciprocating motion with its direction parallel to the major axis of the cylinder (in this case, by way of example, in vertical direction) from the TDC to the BDC and vice versa, opposite and synchronized to the primary piston, and operates with a rapid motion. In fact it acts as a propulsor which is able to generate at the same time pression and depression in one motion from top to bottom, it is subordinated to the turn of an altered overhead camshaft and subjected to a derivative desmodromic mechanism.
DISTINGUISHING CHARACTERISTICS
PASSIVE FUNCTION - As for the moving central section of the S/P, (1/7) the particular installation of this unusual device allows the pouring of the fluid mass (fresh charge) into the same cylinder, it opens when moving upwards during the service stroke, thus carrying out a singular function understood as "scission"(2/6). The automatism of this section is developed in a dynamic way from a mass that moves by inertia and that becomes compact when moving downwards and decomposes into two sections when moving upwards: the central part, which is well fixed to the rod, shaped like a circle and the external part shaped like a floating ring (1/7).
Date recue/date received 2021-10-27 COMBUSTION CHAMBER - In other words it is the space that takes shape when the S/P is in the top dead center TDC (end of stroke), at that moment it assumes the shape and the function of head, thus forming the upper section of the cylinder chamber. Right at the time the end of stroke is reached in the TDC, in the head the S/P temporarily forms the top of the combustion chamber (2/9), namely the space in which the air-fuel mixture is confined at the end of the P/P's compression stroke.
TWO-STROKE - It is determined that with the above-mentioned specifications one has the capacity to employ a sole thermodynamic cycle for one complete turn of the camshaft, therefore this functionality is characterized by the two-stroke principle.
THE BORE AND THE STROKE LENGTH - The geometry of the architecture is designed by calculating the margins of the kinematic process, which is expressed by the value of the "Superquadro" ratio (short-stroke) since the bore value is bigger than the stroke length. This choice is the ideal solution that brings: functional benefits, a decrease in the excursion of the S/P and consequently a reduction in the volume of the organs connected to it.
ANTI-SEIZURE - The S/P is not particularly exposed to the complication of the seizure as it operates attached to the rod (1/1), which moves it in a perfectly linear way, exempt from lateral forces, favoured moreover by its ability to rotate on its own axis. In addition to that, in order to prevent seizure and ensure the lubrification, one row of ball bearings is encased in a groove that encircles the S/P (1/10) and they are immersed Date recue/date received 2021-10-27 into a special grease for high temperatures (like molybdenum disulphide) which makes the motion smoother and reduces the friction with the cylinder pipe. The whole is closed, partitioned and hermetically protected between two compression rings ( 1/8-9) of the synthesized type (carbide, tungsten and steel alloy).
SIZE - The circumference is the same as the bore of the primary piston.
Thicknesses and weights are situational, defined by the design values, the condition of use and the materials employed.
QUICK AND ACCURATE - These adjectives sum up the reactive nature of the S/P unit and the steadiness of the perfectly linear stroke. These benefits are achieved thanks to the fact that the S/P is not attached to a connecting rod but to a linear rod (1/1) and thanks to the consequent absence of lateral forces (given by the effect of flaring due to the upward and downward motion generally related to pistons).
THE HOUSING - The section is defined as the seat of the S/P in the point of upper end of stroke TDC, it draws an analogy with the valve seat of the four-stroke engine from which it takes the technology and the materials employed for the making of this section.
THE SPARK PLUG - It is laterally located for the positive ignition of the combustion and appropriately housed in the upper part of the cylinder, in the combustion pseudo-chamber, therefore it is no longer in the head but it is laterally located, which is an obliged solution to allow the passage of the S/P.
THE MATERIALS AND THE SHAPE - Aluminium alloy forged, from an aesthetic Date recue/date received 2021-10-27 point of view it is similar to a big mushroom valve where, at the center of the disc, is evident a circular intersection. The latter in fact is the passive valve with a tail which is represented by a sturdy linear rod (1/1), whose extremity is predisposed for the contact of the equalizers (2/3). The whole surface is enclosed by the two compression rings (1/8-9) which contain the row of inox ball bearings (1/10).
THE COOLING - In addition to the centralized system of the engine that also cools the cylinder, the S/P enjoys a further benefit due to a thermic exchange and achieved by the fresh charge both during the suction stroke and the scission stroke.
INTEGRATED SYSTEM - All the technologies described in this report take shape in the upper section of the four-stroke engine. The remaining components, which are normally employed for what they have been designed, remain unchanged and they are the pistons, the connecting rods, the camshaft, the change gear, the clutch, the transmissions, the electronic injection, the radiators, part of the distribution, all the electric system of lubrification and the cooling, etc...
The following study in depth is pointed out by simulating the employment of the S/P in a vertical single-cylinder spark ignited petrol fuelled two-stroke engine.
In order to get optimum efficiency from this new technology for the construction of a modern engine, two old technologies have been selected along with a third traditional mechanical organ whose functions are connected with each other and carry out combined actions. It is specified Date recue/date received 2021-10-27 that the S/P is an individual organ which is an end in itself; the connected technologies, hereafter explained, are not binding to its functioning and it can be connected to any device that puts it into motion, be it mechanical, electric or pneumatic in order to get the above-mentioned benefits.
THE FIRST TECHNOLOGY - The choice of the S/P's command system falls on the derivative of a little known system of distribution named "desmodromic". It is distinguished by an essential characteristic, the employment of a faster and more accurate recall mechanical method of the valves; the size of such a system is not sufficient so it is implemented with a structural oversizing, proportionally at an approximate scale of 1:5, notwithstanding the faithfulness to the criterion which it has been invented for. The whole architecture has been clearly designed for an accurate synchrony of the S/P subordinated to the stroke rate of the P/P, which follows the stroke with a uniform and regular rhythm.
THE RATE - Appropriately calibrated, the S/P's command system balances the travel with only two movements (push and pull) with a different rhythm and it is run by a single two-cam shaft setting. Being conceived in this way, it is able to develop a greater load with the necessary energy amplifying the range of action of the equalizer and thus increasing the excursion.
PERTINENT- It is involved, in the same context, a third element as well, an aid-worker of the overhead activity, namely the common "camshaft"
which interfaces among the parts creating a connection: constrained in U
Date recue/date received 2021-10-27 the new architecture, it gets altered as well and in fact, by getting elaborated, its size gets enlarged, specifically the one of the cams (eccentrics) which are definitely much larger, in order to allow a longer excursion on the two independent equalizers (arms), which in their turn operate alternately on the axis of the S/P.
THE SECOND TECHNOLOGY - In order to optimize the S/P's potential at its best, a very versatile passive (it does not absorb energy) one-way distribution device has been adopted and re-used, better known as "lamellar pack", originally used in many two-stroke engines (and air compressors), mainly during the suction stroke (fresh mixture), but now it is also employed as outlet valve, located on the burnt gas outlet pipe at the base of the cylinder. It is made up of a series of lamellae (in carbon, steel, fibre, etc.) which regulate the fluid dynamics of gases that enter the two-stroke engine cylinder.
THE FUNCTIONING - As for the inflow stroke, the principle is similar to the employment in the traditional two-stroke engine but in different modes and times, the function occurs during the stroke in which the S/P
moves downwards, therefore in the cylinder chamber a depression is generated and the lamellar valve, which is located at the top in the cylinder pipe, opens up in the inward direction of the cylinder itself, thus favouring the inflow of the fresh charge, and closes up again once the depression ceases due to the filling of the cylinder chamber. In the next stroke, the exhaust one following the detonation and the gas expansion, a resonance, which produces a pressure increase in the Date recue/date received 2021-10-27 cylinder, is generated; the lamellar valve, which is located on the outlet in the lower part of the cylinder pipe, by receiving pressure, opens up in the outward direction allowing the burnt gas evacuation and after that it immediately closes up, once the pressure ceases and the S/P
moves back up.
THE THREE FUNCTIONS CARRIED OUT BY THE SERVO-PISTON
A) THE EXHAUST - Starting from the TDC, the device intervenes with a little delay after the detonation by calculating the gas expansion time coefficient, the gases give the push to the P/P in the downward stroke, followed by the S/P, which on the contrary is moved by the pulse received from above (camshaft-desmo combo) and by the dynamic suction backpressure (drag phenomenon determined in a gas mass) generated by the wave. During the stroke from top to bottom the S/P, driven by pressure, from the "X"
side quickly pushes the exhaust burnt gases outwards to the lamellar valve (lamellar pack), which has meanwhile opened up following the pressure exerted on it, and to the outlet.
B) THE SUCTION - In the course of the cleaning (exhaust) stroke, which takes place on the "X" side of the S/P, at the same time on the "Y" side the other phase of work occurs, namely the suction (the inflow of the fresh charge, the fuel); the S/P slowly pushes the burnt gases from the "X" side and simultaneously from the "Y" side sucks up the reload. The latter moves down into the empty space, favoured by the depression generated, which in its turn has enabled the lamellar inlet valve (located at the top) to open inwards, thus favouring the inflow of the Date recue/date received 2021-10-27 fresh charge (air/petrol mixture or other fuel) directly into the cylinder chamber and allowing the complete filling; at that point the lamellar inlet valve closes up following the lack of depression. Once the servo-piston reaches the BDC, it has completed the two first phases of the first stroke.
C) THE SCISSION - It is the division of the S/P into two parts, basically it is a new supplementary stroke. This function is possible thanks to the passive valve that allows the advent of the new function, which does not belong to the well-known thermodynamic cycle, and it is precisely described as "functional service stroke". The dynamic process is carried out in the following way: once the BDC is reached (namely the position where the P/P and the S/P are opposite one another), after having discharged the gases to the outlet and preloaded the cylinder chamber with the fuel from the "Y" side, the S/P moves back up a little in advance of the P/P (drawn back up by the camshaft/desmo combo) and generates a turbulence which pours the mass of particles (fresh charge) into the chamber after passage through the opening of the passive valve.
The manoeuvre occurs thanks to the braking given by the friction of the S/P's external section compression rings coming into contact with the cylinder chamber's sheath (dragged by leash).
Once the stroke is completed, at first the central section of the S/P
(valve) houses in its end of stroke in the TDC and immediately afterwards the external section aligns again to the central one, thus reassembling the S/P, thanks to a spiral spring inserted between the two parts (1/12) Date recue/date received 2021-10-27 and to the compression thrust given by the following piston.
FUNCTIONAL EVOLUTION OF THE PRIMARY PISTON
The role played by the power unit (primary piston) in the cylinder chamber in association with the fellow S/P is scaled down to only two active strokes and the piston rate is completely the same if compared to the four-stroke engine, but the background changes. The difference in the process is not made by the piston in itself with its reciprocating motion but by its fellow S/P, which with its aid reduces the strokes from four to two increasing the active work of the piston during the charge compression stroke and the expanding pressure stroke and making itself responsible for the two service strokes, as already described. The shape assumed by the piston, which best fits for this employment, is the Cupa type (like the diesel), characterized by a short skirt with concave top, and it allows to best collect the combustible mixture at the center of the piston, which best absorbs the expanding gases thus limiting the recoil, namely the pressure heading in the opposite direction.
KINEMATIC SEQUENCE OF THE THERMODYNAMIC PROCESS
1st Stroke Regular/lst Action/it Phase/Expansion/Downwards/Picture 2 Once the optimum point of compression in the cylinder chamber is reached (2/2), in the TDC the spark goes off and immediately the detonation of the fuel mixture occurs, followed by the burnt gas volumetric expansion stroke, and the piston moves downwards (2/3-4) reaching the BDC (2/5), Date recue/date received 2021-10-27 thus already completing half turn of the camshaft.
1st Stroke Del. /2nd Action/2' Two-phase/Exhaust/Downwards/Picture 2/X Side Afterwards, in the same first stroke, the S/P follows the action of the P/P (2/3-4) downwards with a little delay (Del.) carrying out the exhaust stroke from top to bottom and pushing the burnt gases towards the lamellar outlet valve (2/5).
1st Stroke Del. /2' Action/2' Two-phase/Suction/Downwards/Picture 2/Y Side At the same time the S/P, in the same above-written action always from top to bottom, from the "Y" side carries out the fresh charge (fuel) preload retro suction stroke (being the fresh charge introduced by a high depression) filling all the space of the stroke from top to bottom in the same cylinder chamber (2/3-4-5).
2' Stroke Advance/3' Action/3' Phase/Scission/Upwards/Picture 3 This completely new stroke, named scission, consists of the advance restart of the S/P from the BDC right before the piston which, by decomposing into two sections and opening up its central valve, manages to move back up cleaving the fresh charge, poured from the "Y" side to the "X" side, to move back into its seat at the end of stroke in the TDC
and then to reassemble, thus forming at that point the top of the head.
2' Stroke Regular/4th Action/4th Phase/Compression/Upwards/Picture 3 Finally the primary piston follows the servo-piston upwards pushing the fluid mass, which is in stasis condition, by compressing it to the top close to the S/P which, at that moment, serves as head (moved by the camshaft that has meanwhile completed the turn).
Date recue/date received 2021-10-27 THE SYNTHESIS - The sequence of events previously described starts with the piston moving down during the expansion stroke, the S/P follows it and from the "X" side pushes the discharged exhaust gases to the outlet and, at the same time, completes the filling of the cylinder chamber by sucking up the fresh charge from the "Y" side, then it moves back up during the scission stroke followed by the piston, which in its turn by moving upwards pushes and compresses the fresh charge to the top close to the S/P. At the time when the S/P and the P/P reach the TDC, once the optimum point of compression is achieved, the spark goes off and ignites the fuel, which by imploding generates the expansion wave. Then it starts again for the following turn of the thermodynamic cycle according to what has already been said about the functioning of this new system.
Date recue/date received 2021-10-27

Claims (6)

1

1. Aluminium alloy two-stroke "servo-piston" service unit for endothermic engines (1/1), it is a thermodynamic device accompanied by the upper and lower compression rings (1/8-9) employed for pressure tightness when coming into contact with the cylinder wall, both during the suction stroke and exhaust stroke, they are of the circular open flat carbide alloy metal L-shaped type, the device is also equipped with a stainless steel recall spring inserted between the external ring and the central disc (1/12) in order to ensure the closure of the former with the latter.

2. The servo piston, as defined in point 1, is characterized by the fact that it is a synchronic biphasic generator both of exhaust gas pressure and of air/fuel mixture preload depression, it is also characterized by a rectilinear and alternative motion with its direction parallel to the major axis of the cylinder, it is opposite to the principal piston in the chamber of the same cylinder and turned upside down at the top of the head in the TDC (2/2).

3. The servo piston, as defined in point 1, is characterized by the fact that it is a multifunctional device equipped with a depressor, it features a concave and convex stairstep (1/5) section for the matching of the central disc with the external ring (1/6-11) and, when it is in its top position in the TDC as head of the cylinder, it reassembles as one flat surface (1/9).

4. The servo piston, as defined in point 1, is a bipartite plate (1/1) characterized by the fact that the disc-shaped central part (1/4) is connected through the connection stem (1/1), which is provided with a downward beat point (1/2) and an attachment for recall (1/3), to a desmodromic distribution system with overhead cams, while the external perimeter section (1/7) is of the mobile floating ring type.

5. The servo piston, as defined in point 1, is characterized by the fact that it is manufactured with a self-cooling system, prior to the heat exchange which occurs when it moves through the fresh preload previously sucked up from the BDC to the TDC (2/7-8) during the scission stroke.

6. The servo piston, as defined in point 1, is characterized by the fact that it is of the dry-type and self-lubrificating as it is encircled by one row of steel ball bearings (1/10) which are contained in an elastic cage, immersed into a special grease and interposed between the upper and lower compression rings.