ITPO20110011A1 - ROTARY ENGINE WITH INTERNAL COMBUSTION, VARIABLE STROKE OR NOT, EIGHT OR DIESEL CYCLE. COMPOSED OF A STATOR AND A CYLINDRICAL ROTOR THAT CONTAINS THE OFFICES FOR TWO OSCILLANT PISTONS IN ITS ENTRY. SUCTION AND EXHAUST THROUGH TRANSFER LIGHTS. - Google Patents

Description

DESCRIPTION

4-stroke, 2-piston internal combustion engine, with 4 die stages being completed in one revolution.

It can be Otto cycle or Diesel, and / or turbo. It can be assembled in several units, that is, it is modular.

The motor is represented in Table 1. In the drawing above, its main components are highlighted, such as: the stator (Table 1 / A) of cylindrical shape, the rotor (Table 1 / B) also of cylindrical, which turns inside the stator, and two pistons (Table 1 / C), whose seats are contained within the overall dimensions of the rotor. N.B. The engine is shown rotated at an intermediate point between Top Dead Center (TDC), and Bottom Dead Center (PMI).

The pistons are of particular shape, and could resemble, in shape and movement, the shoes of a drum brake, which were however pivoted in two diametrically opposite points of the rotor, i.e. staggered by 180 degrees, and therefore both oriented in the same direction. clockwise (or counterclockwise).

The two pistons perform a rather complex oscillating movement. Each piston is hinged, through one of its ends, to a peripheral point of the rotor. Consequently, the piston, through the hinge (Tab. 1 / D), is bound to follow the circular path (Tab. 1 / E) generated by the rotor. Instead the central part of the piston follows an elliptical path (Table 1 / F). (Hereinafter, instead of 'elliptic' read 'elliptic or pseudo-elliptic').

The elliptical path is concentric with the circular path, and is placed inside it, so it is smaller. But since, obviously, the points of the ellipse are not equidistant from the center, in order to follow the ellipse, the piston is forced, with its median part, to approach and move away from the center, thus causing the reciprocating motion. The elliptical path constitutes the axis of an elliptical groove (Table 1 / G), duplicated on the two sides of the motor.

The two bearings (Tab. 1 / H) belonging to each piston pass through these grooves.

(Hereinafter, instead of “bearings” read “bearings or bushings').

The central drawing of Table 1 is a section passing through the major axis of the ellipses.

The part radially external to the elliptical groove is called external ellipse (Plate 1/1), the radially internal part is called elltoae intema (Plate 1 / L). These two elliptical bodies are coplanar, and constitute the radially internal and external guides of the bearing. Consequently, the distance between the outer and inner ellipses is equivalent to the bearing diameter while the depth is equivalent to the bearing width (beyond tolerances).

Between the stator and the ellipse there is a 'diaphragm' (Table 1 / M), similar in shape to the large ellipse, it has the function of increasing the separation surface between the crankcase and the combustion chambers.

Ideally it is the equivalent of the 'jacket' of the conventional engine.

The diaphragm repeats the shape of the external ellipse, its elliptical hole is smaller than that of the external ellipse, because the bearing passes through the latter, while the bearing pin passes through the diaphragm.

The thickness of the diaphragm is minimal, and is equal to the distance between the piston and the bearing.

Externally to the ellipses there are two 'cheeks' (Table 1 / N) which seal the stator on both sides.

The entire cheek-ellipsis-diaphragm package is present on both sides of the stator, it copies its shape and external size, and is integral with it.

Cheek and ellipse (s), and / or diaphragm and outer ellipse, can also be grouped and fused together.

The bottom drawing of Table 1 shows the pistons at TDC (Table 1/0), and PMI (Table 1 / P).

Table 2 represents the exploded engine, assembled with the upper side '' uncovered <*>.

In evidence on the stator the luds and the fòro candle, which we will see better later.

The PISTON has a crescent shape, and is represented in Table 3 with its exploded and assembled parts. In the drawing above it can be seen that it has two large through holes, parallel to the axis of the rotor.

A hole (Tab. 3 / A) is placed in the median area and houses the pin (Tab. 3 / B) of the bearings (Tab. 3 / C).

The other hole (Tab. 3 / D) is placed at the end of the piston, and houses the pin (Tab. 3 / E) of the hinge (Tab. 3 / F) which articulates the piston to the rotor. The two lateral faces of the piston are called flat shell (Tab. ZIG), the opposite face to the hinge is called curved shell (Tab. 3 / H).

The piston also has a series of small holes which constitute the passages of the lubricant.

They have an entrance from the intrados of the piston (Table 3 / M), and an exit on the side skirts (Table 3 / N).

The drawing below shows the combustion chamber (Tab. 3 / L) which is obtained in the top of the piston (Tab. 3/1). It is placed on its free end (the one opposite the hinge), in order to maximize the combustion thrust. In fact, if we consider the piston as a second kind lever (chiacdanoci), the combustion chamber must be placed on the positive arm of the lever.

The ROTOR is represented in Table 4 with the relative “elastic bands <*> assembled and exploded.

It also has various holes for lubrication. Both of these aspects will be clarified in the respective paragraphs "Seals <*> and 'Lubrication <*>.

The rotor is cylindrical in shape, but this shape is interrupted by the two volumes formed by the pistons and their strokes. This cylindrical shape is ideally reconstituted by the pistons, when these are at TDC (except for the combustion chambers). The drawing below shows how the rotor has the hinges in the periphery (Tab. 4 / E), and the relative pin holes (Tab. 4 / D), by means of which the pistons are articulated to the rotor. N.B. I drew the “female <*> parts of the hinges on the rotor, and the“ male <*> parts on the pistons, but it is evident that they can also be reversed.

The STATOR (Tab. 2 / A) contains the rotor, and therefore has the same cylindrical shape.

LIGHTS (or transfers) are obtained on the stator (and / or on the guanda-ellipse-diaphragm sandwich), which allow the gaseous fluids to enter and exit. It is the rotor that with its rotary motion discovers and then covers (with the Intake port (Tab. 2 / B), and subsequently the Discharge port (Tab. 2 / C), thus allowing the mixture to enter and exhaust of the burnt gases, similar to what happens in the 2-stroke engine.

Furthermore, the hole (Tab. 2 / E) of the spark plug (Tab. 2 / E) is housed on the stator.

GASKETS, or bands, seal each unit volume on all sides, some are housed on the piston, others on the rotor near the piston. Similarly to the "piston rings" of the alternating engine, they prevent the mixture and gases from penetrating the crankcase, and the oil from penetrating into the combustion chambers.

The seals on each piston are five, and they surround the sky. Two curved gaskets (Tab. 3/0), are placed on each flat shell, a long gasket (Tab. ZIP) is placed on the curved shell, and two short gaskets (Tab. 3 / Q) are placed in correspondence with the parts of hinge belonging to the rotor.

On the rotor four other seals complete the seal of each unit volume, are illustrated in Table 4. N.B. For descriptive simplicity, the seals of a single piston are shown in Table 4 below. A straight gasket (Table 4 / A) and parallel to the rotation axis, is placed on the external curved face of the rotor, at the end of the space occupied by each piston, on the side opposite the hinge.

Another gasket parallel to the rotation axis, is placed on the external curved face of the rotor, and is adjacent to the hinge, it is called straight hinge gasket (Tab. 4 / B). Finally, two curved gaskets (Table 4 / C) are placed on the internal face of the rotor, and are in contact with the curved piston skirt and with the diaphragms.

All the seals are pushed by the centrifugal force towards the stator, so they work in the right direction.

However, the curved seals (on the pistons and on the rotor) must also guarantee sealing towards the lateral diaphragms, that is, in a direction orthogonal to the centrifugal force. Therefore, if necessary, the thrust towards the diaphragms can be assisted by serpentine or other shaped springs.

For reasons of space, it is preferable to avoid using multiple bands (seal and oil scraper) as in the alternating engine, but single “multi-function 'bands, as in the Wankel engine.

The entire cycle of the FOUR PHASES is completed in a single turn.

Table 5 shows the operation illustrated in various successive steps (18 steps in half a turn, one every 10 °).

1st Phase: Aspiration. The piston drops from TDC to PMI. The rotor has already discovered the Intake Light and enters the mixture. At the end of the Phase, the rotor begins to cover the Intake Port.

2nd Phase: Compression. The piston rises from PMI to PMS. The Light of Aspiration closes, and Compression can take place.

3rd Phase: Burst-Expansion. The piston is back at TDC. The spark fires, and the piston is pushed towards the PMI, and then the rotor is induced to rotate. At the end of the Phase, the opening of the Exhaust Port begins. 4th Phase: Unloading. The piston rises from BDC to TDC and unloading takes place. At the end of this Phase, the rotor begins to cover the Exhaust Port, and uncover the Intake Port.

Simultaneously the other piston does the same Phases, but postponed by two (while one piston is in the first Phase, the other is in the third Phase, etc.). So, having the engine with two pistons, it will have two bursts per revolution, one every 180 degrees.

It can be observed how each piston makes the stroke from TDC to BDC, due to the different diameters of the ellipse. Therefore TDCs occur when the piston bearings are at the vertices of the largest diameter of the ellipse, that is, when they are at 90 ° and 270 ° degrees of the ellipse (with respect to the 0 ° trigonometric). PMI when the bearings are at the vertices of the smallest diameter, i.e. at 0 ° and 180 ° degrees.

It can be noted that, when the pistons are at TDC, together with the rotor, they form a circular shape which completely seals on the stator, except for the combustion chambers.

When the piston is at the PMI, its hinged side has remained adherent to the stator, while the body is rotated around the hinge, following the ellipse, and therefore approaching the center of the rotor.

Note that the piston is subjected to two different rotations at the same time. As it revolves around the rotor, it also rotates around the hinge.

Table 6 / A shows the rotor angles when the pistons are at TDC and PMI.

Table 6 / B shows the schematic graph of the 4 Phases. Indicates the angles of the start of Lights opening, and completion of Lud opening, and the angles of start of Lights closure, and completion of Lights closure.

The geometry of the engine makes the piston descent from PMS to PMI faster than the ascent from PMS to PMS. That is, the piston moves faster in the Intake and Burst phases, compared to the Compression and Exhaust phases, while in the conventional connecting rod engine the descent and ascent speeds are the same.

In the Burst Phase, which is the one that creates the power, the burnt gases work more effectively if they encounter a piston that "collapses" quickly under the thrust. That is, there is a higher Thermodynamic Efficiency.

This difference between the descent and ascent speeds can be controlled in the design phase, as it is directly proportional to the hinge-bearing distance, with respect to the total length of the piston.

To decrease the difference between the two speeds, it is sufficient to redesign the piston alone, bringing the bearing closer to the hinge, and leaving the other dimensions of the piston and of the other engine components unchanged.

The diagram in Table 6 / C shows the comparison with the Cido Otto engine, both from PMS to PMI.

The hypothetical engine for comparison is also 218 cc, with a bore and stroke of 65.3 mm, connecting rod 130.6 mm. On the abscissa the rotation of the crankshafts, from TDC to PMI. In ordinate the percentage increase of the trips. Note that, compared to the Cido Otto, throughout the stroke, the piston is lower, where the expansion is greater. The maximum advantage <*> percentage (Table 6 / D), occurs when the rotors are at 34.5% of the rotation from TDC to PMI, where the drop is at 47.3% of the entire stroke, while in the connecting rod motor remained at 31.5%, doè 50.2%.

It is possible to slowly redesign the engine, making it a VARIABLE STROKE, and therefore a variable displacement. The compression ratio usually adopted varies from 1:10 to 1:12. But the volumetric expansion ratio of the flue gases is much higher than these numbers, and would require an ideal compression ratio of 1:14. But in conventional engines, not being able to reach high compression values (for reasons beyond this point), it is necessary to renounce to exploit all the energy produced by the explosion.

The way to get around this limit is to design a variable stroke engine, where it has a certain stroke and displacement at the intake, and a larger stroke and displacement when expanding.

In this way, a higher compression ratio can be adopted.

Then the mixture, exploding and expanding from the PMS to the PMI, will meet a greater volume, and will have the possibility of exploding all on the piston deio, where it produces power, and not in the exhaust manifold, where it can no longer produce it. Ultimately, better performance and operating economy are obtained.

I obtain the variable stroke by modifying the geometric shape of the elliptical path, that is, making it “asymmetrical <*> (Table 7 / A). Considering the ellipse as formed by two parallel parabolas, I adopt two different measurements for the two minor radii of the two parables. That is, the smaller radius of the larger suction side parabola (Tab. 7 / B), and that of the smaller expansion side (Tab. 7 / C).

Therefore the piston stroke will be short in suction (Tab. 7 / D), and longer In expansion (Tab. 7 / E). Ultimately, the displacement will be small in suction (Tab. 7 / F), and larger in expansion (Tab. 7 / G).

LUBRICATION. The oil reaches all points of the engine in motion.

In Table 8 the arrows indicate the direction of the lubricants.

(N.8. For ease of reading I have drawn the Rotor with the seals incorporated).

The oil enters the engine through two paths, the first through the cheeks, the second through the rotor.

The drawing above is a section passing through the major axis of the ellipses.

Through each cheek, an oil channel lubricates the bench support (Table 8 / A).

Again through each cheek, a jet of oil lubricates the elliptical groove (Tab. 8 / B) crossed by the bearings, and the bearings themselves when they pass under the jet.

The other oil inlet takes place through a canalization obtained axially to the rotor (Tab. 8 / C).

From here a series of channels branch out, all incorporated in the rotor, and which reach the various points to be lubricated. The other end of the rotor contains a similar channel from which all the oil comes out (Table 8 / P).

From the axial channel of the rotor, the oil continues through the long channels (Table 8 / D) obtained in the two radial arms of the rotor, and progressively reaches the various other areas.

The oil comes out towards the hinge of each piston, through two ducts (Table 8 / E), obtained between the male and female components of the hinge, and bypassing the pin.

Through two holes, folio exits on the external curved face of the rotor (Plate 8 / F), from here, due to the rotation, it wets the whole face, in the direction of the arrows (Plate 8 / G).

Finally it is sprayed by the long jets (Tab. 8 / H) towards each internal curved face of the rotor (Tab. 8/1), that is the face where the curved skirt of the piston slides.

The oil that had been introduced on the external face of the rotor, due to the effect of the rotation, has slid along this surface, in the direction of the arrows (Table 8 / G), at the end of the path it is trapped by the system of seals, and finds the single outlet in the oil recovery holes (Table β / L), present on the external dregs of the rotor. From here, through the long V-shaped converging channels (Plate 8 / M), placed at the periphery of the rotor, it is sent towards the long radial channels (Plate 8 / N) obtained in each of the rotor arms.

All the oil introduced into the engine, after having lubricated the relative targets, ends up in the crankcase, from where due to the effect of the centrifugal force, it is projected under the piston crown, and due to the effect of the rotation it runs through it in the opposite direction to the rotation of the rotor. and cools it.

A part of this oil is intercepted inside the piston, and is pushed by the centrifugal force into a series of channels that go from the intrados of the piston (Tab. 3 / M), towards the flat skirts (Tab. 3 / N ).

The rotation and back and forth of the piston causes this oil to wet the entire gap between the flat shells and the stator.

The oil that has passed through the intrados of the pistons, after having climbed over the hinges, is stopped by the collection bags (hatched area in Table 4) contained in the two large radial arms of the rotor.

From here, through the holes (Tab. 8/0), it enters the long radial channels (Tab. 8 / N), from where it is conveyed into the oil drain channel (Tab. 8 / P) coaxial to the crankshaft , and therefore can exit towards the oil filter.

The DESIGN ISSUES are similar to those of another internal combustion rotary engine: the Wankel.

I designed the engine with the best known Wankel currently in production as a comparison, namely the Mazda RX-8 sports coupe.

The Mazda Wankel is a 230 HP (170 kW), 1308 cc twin-engine. Each rotor is 654 cc, and since each rotor has 3 bursts per revolution, this results in 6 bursts per revolution and a unit displacement of 218 cc.

To check the consistency of my design, I chose the same 218cc unit displacement as the Mazda, and since my rotor has 2 pistons, a total displacement of 436cc follows, with 2 bursts per revolution.

To have a complete volumetric equivalence with the Mazda twin-engine, my engine would have to be a tri-rotor, thus forming a similar 6 "cylinder <*> 1308 cc engine unit, and 6 bursts per revolution.

The Wankel is equated, by sporting regulations and by the tax authorities, with a conventional double displacement engine.

The Peripheral Speed of the Rotor is one of the critical parameters of the Wankel, and of the motors in general.

Given that the Mazda rotor is 3000 rpm (while the crankshaft is 9000 rpm, that is triple), and that the stator diameters are 164 mm and 125 mm, it follows a linear development of the stator of about 470 mm. , consequently the rotor has a peripheral speed of 23.6 mt / sec.

To calculate the maximum design rpm of my engine, I set the same Exact Peripheral Rotor Speed of 23.6 mtfaec as the Wankel Mazda as the limit.

It should be emphasized that this data is not comparable with the Average Piston Speed (VMP) of the alternating motor. As in the latter, the speed varies from zero at TDC, then increases and becomes maximum at about halfway, and then decreases until it becomes zero again at PMI. Hence, in the reciprocating motor, the VMP is the average of these speeds, consequently the maximum speed is obviously much higher than the average speed.

On the other hand, in a rotating motor, the peripheral speed is always constant during the revolution.

Having my motor with a rotor diameter of 180 mm, i.e. 5Θ5 mm of linear development of the stator, with the Peripheral Speed limited to 23.6 mt / sec, it can run at maximum at 2504 girl, which is very close to the 3000 rpm of the Mazda.

Without increasing the Peripheral Speed, a relative increase in displacement is possible. This is achieved by increasing the width and length of the pistons, i.e. without affecting the rotor diameter.

The MEASURES hypothesized by me, in the case of a standard chorea engine, are:

Unit displacement 218 cc, Total displacement 436 cc.

Rotor diameter 180 mm.

Width of the rotor-piston 63.6 mm. (ideally corresponds to the bore of the alternating motor).

Length of the piston, from the hinge to its opposite face (the curved skirt), 143 mm.

Distance from hinge to bearing, 99.8 mm.

Diameter of the circumference passing through the hinges of the two pistons 159 mm.

Angle formed by the piston, passing from PMS to PM1 1932 °.

Linearized piston stroke 48.22 mm (measured at the end).

Bearing dimensions (rollers, commercial type): external diameter 22 mm, internal diameter 10 mm, width 13 mm, admitted dynamic load 8.8 kN, fatigue limit load 1.25 kN, weight 23 gr each.

Dimensions of the elliptical path: major diameter 109, minor diameter 58.7 mm.

With these bearings, the dimensions of the elliptical groove that houses the bearings (subject to tolerances) are:

Throat width 22 mm (equal to the bearing), external diameters 131 x 80.7 mm, internal diameters 87 x 36.7 mm.

The diameters of the diaphragm ellipse, in which the bearing pin travels: 119 x 68.7 mm.

The combustion chamber, obtained in the deio of the pistons, has a volume of 24.20 cm3.

Compression ratio of 10: 1.

The MEASURES hypothesized by me, in the case of a variable chorea motor, are:

Ratio between intake capacity and expansion capacity equal to 1: 1.5

Unit displacement in aspiration 145.4 cc. (Unit displacement in expansion 218 cc unchanged).

Angle supplied by the piston, passing from PMS to PM1 12.88 ° (Intake side).

Linearized stroke of the piston 32.15 mm (measured at the end) (Intake side).

Smaller radius of the elliptical path on the Intake side 37.14 mm (Expansion side 29.35 mm unchanged).

All other measures remain unchanged.

Various considerations in favor of my engine:

a) Low speed motor. The limit of 2504 rpm that I have imposed, may seem low, but it is not for a rotating engine, infected are almost the same rpm as the brilliant Wartkel Mazda (3000 gin).

This is because it must be considered that the significant data is not the number of revolutions, but the number of bursts per minute. Infect my engine, with 2 bursts per lap, at 2504 rpm I will do 5008 bursts per minute. Which are the same bursts per minute of a 2-cylinder Otto engine, but those same bursts will hurt them at double the revs, that is 5008. If instead we consider a bi-engine, it would make the same bursts per minute of an Otto cycle engine. 4-cylinder. Etc. In general, my engine compared to an Otto cycle engine, and with the same number of pistons, has the same number of blowouts per minute, but at half revs.

As a result, in an engine designed to run at low rpm, Γ component wear is low.

b) Filling coefficient higher than in the reciprocating engine.

My engine has the prerogative of working at a low number of revolutions, and since it is known that the filling is higher at low revs, it follows that the engine is highly filled, that is, it can take in a large amount of 'air'. Consequently, the power is also higher.

c) High Thermodynamic Efficiency compared to the alternating motor.

As already seen, the descent of the piston from PMS to PMI is faster than the ascent from PMS to PMS (in the alternating motor the two speeds are the same).

The expansion phase, which is the one that creates the power, is facilitated by the sudden descent of the piston, and therefore by the sudden expansion of the volume. A piston that 'collapses <*> quickly, is able to support the propagation of the flame front more quickly, that is, there is a better use of fuel.

d) Low suction pressure drop, because the mixture passes through short, straight, large section ducts without obstacles. The evacuation of flue gases is also facilitated by this type of ducts.

While in the reciprocating engine, the gaseous fluids must pass through tight curves and bottlenecks (between the valve and the manifold), and bypass obstacles (the valve stem).

e) Better Consumption, Power and Pollution of the reciprocating engine.

The Intake and Exhaust ports are extremely spaced, and this minimizes the risk of flow crossings, and of fresh mixture leaking through the exhaust.

Therefore, by widening the lights, it is possible to create a more sophisticated Distribution Crossing motto than in conventional engines. The result is an increase in the 'trapped' mixture before the exhaust port closes. In this way, a higher Filling Coefficient is obtained, which has a positive impact on Consumption, Power and Pollution.

As seen, the intersection can be increased by widening the lights, that is, anticipating the opening of the intake port, and delaying the closing of the exhaust port. But it can also be achieved by 'lengthening' the piston, that is, lengthening the distance from the game bag to the opposite point, where the curved mantle is.

In the alternating engine, on the other hand, the intake and combustion chambers coincide, and since the valves are adjacent, the Distribution Crossing connects the intake and exhaust ducts, as in the Wankel.

1) There is no risk of self-ignition because the intake and combustion chambers are distant and clearly separated, ie the fresh mixture cannot meet "hot <*> areas.

There is no risk of flame return, because the large distance between the intake and exhaust ports minimizes the risk of the burned gases refluxing into the intake manifold.

These two prerogatives could favor the study of alternative fuels such as hydrogen. In the alternating engine, on the other hand, the intake and combustion chambers coincide.

g) Absence of vibrations, because the engine is balanced per se.

The crankshaft is symmetrical, and the only masses in reciprocating motion are the two pistons, which work in harmony that is, they approach and move away simultaneously.

While in the case of variable stroke, since the motion of the two pistons is not identical, the motor requires balancing.

h) All the seals always work at a constant angle on the corresponding surface, as in traditional engines.While in the Wankel the apical seals continuously vary the angle with the stator during the revolution, which entails rapid wear of the seals (replacement every 40,000 km ).

Furthermore, in the Wankel, since the apical seals rebound due to the recesses between the stator lobes, vigorous motion springs have been adopted, which worsen the wear of the seals themselves and of the stator.

i) Economy and simplicity of construction, because the motor is made up of few components.

There are no classic components of the alternating engine distribution, such as camshaft, valves and related settings, springs, tappets, rocker arms, gears and timing belt.

The function of all these organs is performed only by the lights, as in the 2-stroke engine and in the Wankel.

Moreover, since the rotor itself is in rotary motion, there are not even those organs which in the alternating motor transform the motion from rectilinear to rotary, such as connecting rods and crankshaft.

The function of these organs is performed by the ellipses alone.

I) There are no contraindications to designing the diesel engine by adjusting the Compression Ratio. There are no contraindications even to make it turbo, nor to make it direct injection.

It is possible to assemble several motors in Modular form, such as the Wankel:

If double-engined, they must be offset by 90 degrees, and there will be 4 bursts per turn and one burst every 90 degrees.

If Trirotore, they must be staggered by 60 degrees, and there will be 6 bursts per turn and one burst every 60 degrees. Etc.

I am not aware of anything like this pre-existing. The similarities with the pre-existing engines can be summarized as follows: Rotating engine, like the Wankel. Four phases, like the Wankel and like the 4-stroke engine.

Intake and Exhaust via Lud, like the Wankel and like the 2-stroke engine. The Lud are uncovered and covered by the rotor, while in the 2-stroke engine they are uncovered and covered by the piston.

Claims (8)

CLAIMS 1) Internal combustion rotary engine. Consisting of a cylindrical rotor which houses inside the housings for two oscillating pistons. The rotor rotates inside a cylindrical stator which is closed by two bases. 2) Each piston has the shape of a “crescent.” One of the two ends is hinged to the periphery of the rotor, and follows a circular path, always equidistant from the center. Instead, the opposite end of the piston can oscillate inside the rotor, as the central part of the piston follows an elliptical path, coaxial and integral with the lateral bases that close the stator. Therefore, the pistons are forced to follow the ellipse, that is, they approach and move away from the center of the rotor, causing the reciprocating motion. 3) Transfer ports, arranged on the stator (and / or on the side bases), allow the entry and exit of fluids. It is the rotor with its motion, which uncovers and covers the intake and exhaust transfer ports. 4) 4-stroke rotary engine that completes the entire ddo in a single revolution. Compared to a 4-stroke alternating engine, with the same number of pistons, it produces the same number of blasts per minute, but at half revolutions per minute. 5) The descent of the piston from TDC (top dead center) to PMI (bottom dead center) is faster than the ascent from PMI to TDC. Compared to the reciprocating engine, at each moment of the Expansion Phase, there is a greater volume available for the expanding gas. So there is a better Thermodynamic Efficiency. 6) The intake and exhaust manifolds are short, straight, with a large section and without obstacles, i.e. there are Low Losses of Intake Load. On the other hand, in the alternating engine, the gases must pass through bottlenecks (between the valve and the manifold), and go around obstacles (the valve stem). 7) Intake and Exhaust are extremely spaced, thus reducing the risk of Flame Return, and of fresh mixture leaking through the exhaust. Consequently, it is possible to adopt a very thorough intersection of the intake and exhaust phases, compared to the alternating engine. In other words, a higher Filling Coefficient is obtained, and consequently a better Thermodynamic Efficiency. Ultimately, better consumption, power and pollution of the alternating engine. 8) The combustion and intake chambers are separate, so there is a reduced risk of self-ignition. S) The engine can also be designed with Variable Stroke, and therefore with Variable Displacement. We can have the piston stroke short in the Intake phase, and long in the Burst phase. To achieve this, I modify the shape of the ellipse, and consider it an "asymmetrical" ellipse. That is, I consider the ellipse as formed by two adjacent parabolas, and I adopt two different measurements for the minor radii of the two parabolas. of the parabola which concerns the suction phase, is larger than the minor radius of the parabola which concerns the bursting phase. Consequently, the displacement in the intake phase is smaller than the displacement in the combustion phase.