WO2008029426A1

WO2008029426A1 - Volumetric machine comprising a toroidal chamber, divided into variable-volume sections by one or more separation valves, in which at least one toroidal- sector piston slides

Info

Publication number: WO2008029426A1
Application number: PCT/IT2007/000590
Authority: WO
Inventors: Emanuele Spada
Original assignee: Emanuele Spada
Priority date: 2006-09-07
Filing date: 2007-08-21
Publication date: 2008-03-13
Also published as: ITCT20060019A1; EP2061952A1

Abstract

Described herein is an apparatus characterized in that it comprises a toroidal chamber having a preferably (but not exclusively) circular cross section, with one or more controlled separation valves that identify a characteristic angle on the circumference of revolution of the torus, each of which is designed to be opened, when it is about to be reached by a toroidal-sector piston that turns within the chamber itself, so as to allow the piston to pass, and to be closed as soon as the piston passes beyond it, dividing the chamber into at least two sections, the variability of which enables exchange of energy between the fluid and the piston; each of the aforesaid sections is delimited by the wall of a closed separation valve or of a piston and by the wall that faces it, whether it belongs to the same piston or to another piston or to another separation valve.

Description

Volumetric machine comprising a toroidal chamber, divided into variable-volume sections by one or more separation valves, in which at least one toroidal- sector piston slides

*****

The present invention basically regards the sector of internal-combustion engines (in what follows ICEs) and hydraulic tractor machines and roadwork and building-site, machinery, in which the types of machines that currently cover the majority of applications are:

- piston engines with cylindrical combustion-chamber

(in two-stroke or four-stroke versions, either normally aspirated or supercharged, supplied by petrol, diesel, gas, etc.) , which are widely used notwithstanding the low efficiency with respect to the energy potential contained in the fuel, and Wankel engines, which have a more limited diffusion;

- blade turbomachines (gas or steam hydraulic turbines, turbojets, turbopumps, turbosuperchargers, turbo-aspirators, turbofans, etc. ) ; and

- piston-cylinder worksite machinery and other volumetric machines with small ranges of application as compared to the foregoing, such as scroll machines, Roots machines, Archimedes' screws, gear pumps, ^• and other minor types.

The main purpose of the invention is to provide a new type of machine or apparatus having characteristics of considerable technical and commercial importance, such as marked versatility of use and application, high mechanical efficiency, high thermodynamic efficiency in the case of use as ICEs, high fluid-dynamic versatility in the case of use as worksite machinery, high adaptation to the working conditions in the case of use as tractor machines.

More specifically, the versatility of the invention is represented by the fact that it is able to function, with simple variations, such as the presence or otherwise of certain components (injectors, spark plugs, expansion boxes) and with the appropriate arrangement and calibration of the fluid-inlet/outlet valves, as ICE, as worksite machinery (pump, compressor, aspirator, or fan) or as hydraulic, gas or steam, tractor machine (equivalent to a turbine) with the obvious possibility of being made of any size (and with the possibility of application to the sector of motor vehicles, to industry, etc.) .

As regards mechanical efficiency, it is to be noted that the present invention is not subject to the losses due to inertia inherent in the reciprocating motion of the piston of piston-cylinder machines, albeit preserving the constructional simplicity thereof as compared to blade turbomachines .

As regards its application as ICE, it should be noted that an expansion box is provided, which enables preheating of the air to be introduced into the combustion chamber, thus recovering part of the energy that in traditional piston-cylinder engines is inevitably lost with exhaust of the fumes and heating of the engine, without jeopardizing the degree of filling and the volumetric efficiency, freeing the compression ratio from the "noxious volume", i.e., the part of exhaust gases that is not expelled. In the case of use as worksite machinery, the invention enables convenient regulation of the capacity independently of the pressure head: the capacity is varied by modifying the r.p.m., whilst the pressure head is controlled by acting on the calibration of the delivery valves.

Finally, in applications of the invention as tractor machine, it is possible to adapt operation of the apparatus to the variations in the conditions of the fluid at inlet, by acting on the timing of the controlled intake valves.

The foregoing has been obtained envisaging an apparatus characterized in that it comprises a toroidal chamber having a cross section that is preferably (but not exclusively) circular, with one or more controlled separation valves, which identify a characteristic angle on the circumference of revolution of the torus, each of which is designed to be opened, when it is about to be reached by a toroidal-sector piston that turns within the chamber itself, so as to allow said piston to pass, and to be closed as soon as the piston passes beyond it, dividing the chamber into at least two sections, the variability of which enables exchange of energy between the fluid and the piston; each of the aforesaid sections is delimited by the wall of a closed separation valve or of a piston and by the wall that faces it, whether this belongs to the same piston, or to another piston, or to another separation valve.

A better understanding of the invention will be obtained from the ensuing description with reference to the annexed plates of drawings, which illustrate, purely by way of non-limiting example, some preferred embodiments of the invention.

In the plates of drawings:

Figure 1 is an exploded view of the main components of the invention;

Figures 2A, 2B, 3A, 3B show the plane shapes that generate by revolution the components of the invention constituted by solids of revolution and the axes about which said shapes turn; Figures 4, 5, 6 and 7 are 3D views of some parts of the invention;

Figures 8 to 13 show the steps of operation as ICE of a first embodiment of the invention;

Figures 14 to 17 show the steps of operation as worksite machine of said first embodiment;

Figures 18 to 21 show the steps of operation as tractor machine of said first embodiment;

Figures 22 to 30 show the steps of operation as ICE of a second embodiment of the invention; Figures 31 to 37 show the steps of operation as ICE of a variant of said second embodiment;

Figures 38 to 44 show the steps of operation as ICE of a further variant of said second embodiment;

Figures 45 to 48 show the steps of operation as worksite machine or tractor machine of a third embodiment of the invention.

With reference to Figures 1 and 4-7, a first embodiment of the machine or apparatus according to the present invention basically comprises: 1. two outer half-shells 1, designed to be assembled for providing an annular body, each of which is basically formed by an arched body with development according to the arc of a circle, having the concave side provided with a toroidal groove and the ends provided with flanges l^r for mutual fixing to the other half-shell;

2. an inner block 2, which is designed to be enclosed between said half-shells 1 and has a basically annular body with the outer side provided with a toroidal groove mated to those of the half-shells themselves ^* to form a toroidal chamber with circular or elliptical cross section;

3. a piston 6, having a toroidal-sector body with circular or elliptical cross section, designed to slide within the toroidal chamber; 4. two separation passing valves 4a and 4b, each of which is basically constituted by a sliding diaphragm set crosswise to said toroidal chamber, and which are designed to be controlled in a known way for closing/opening the chamber itself at the passage of the piston 6;

5. four nonreturn valves Vl to V4 , either automatic or controlled, housed in purposely provided seats 5 for regulating the inflow/outflow of the fluid into/out of the toroidal chamber; 6. a driving shaft 9, having a basically cylindrical tubular shape sharing the main axis AP of the toroidal chamber in which the piston 6 slides;

7. circumferential sealing means 10a and 10b, set respectively between the driving shaft 9 and the outer half-shells 1 and between the driving shaft 9 and the inner block 2; and 8. a circular end plate or base 11, designed to close an inner chamber delimited by the empty space within the annular body of the inner block 2, said base being set on the same side as the driving shaft 9.

In the example illustrated, each of the two outer half-shells 1 is formed by the solid of revolution generated by the corresponding shape of Figure 2B, which describes an angle α = 180° in its motion about the main axis AP. In the general case, the two half- shells 1 can have a different amplitude, respectively equal to α and 360° —a.

The ends of said half-shells (parallel to the axis of revolution or main axis AP) have a height that considerably greater than the rest of the annular body and are each formed by the solid of revolution generated by the corresponding shape of Figure 2A that describes a small angle, thus constituting the outer half-flanges 1' for mutual fixing of the half-shells 1 themselves. Made within the flanges 1' are holes for the tie-rods 3 that keep the machine assembled, as well as half of the seats of the controlled separation valves 4a and 4b.

Said inner block 2, enclosed between the outer half-shells 1 to form said toroidal chamber with circular cross section, is formed by the solid of revolution generated by the corresponding shape of Figure 2B, which describes an angle of 360° in its motion about the main axis AP. In a position corresponding to the four half- flanges 1' of the outer shells 1, the inner block 2 is provided with transverse ^' elements with axial development, referred to as counterflanges 2' , which are designed to co-operate with the half-flanges 1' of the outer half-shells 1 (Figure 2A) . According to a peculiar characteristic of the invention, said counterflanges 2' form an enlarged portion where the remaining half of the seats, within which the controlled separation valves 4a and 4b slide, are made. The annular body of the inner block 2 comprises a central cavity or inner chamber (Figures 1 and 4-7), which, in the case of operation as ICE, forms the expansion box P of the apparatus.

It should be noted that, according to the invention, in the case of operation as tractor machine or worksite machine, the same inner chamber functions instead as terminal part of the intake manifold A for the working fluid.

Each of the controlled separation passing valves 4a and 4b is constituted by the solid of revolution generated by the corresponding shape of Figure 3A and 3B that describes an angle of a few degrees in its motion about the axis. In the figures, said valves are represented in the two end positions of their stroke: at the bottom dead centre 4a, in a position such as to enable passage of the piston 6, and at the top dead centre 4b, in a position such as to close the toroidal chamber before and after passage of the piston itself.

For this purpose, in the example illustrated, each of said controlled valves 4a and 4b is constituted by a sliding diaphragm provided with a through opening in a position corresponding to the cross section of the toroidal chamber within which the piston or plunger 6 slides .

The aforesaid four nonreturn valves Vl to V4 (housed in their own seats 5) designed to regulate the inlet/outlet of fluid into/out of the toroidal chamber can be, according to the cases, either automatic (opening/closing determined by the pressure of the fluid and by the calibration pressure) or else controlled.

Two of the corresponding seats are made in the outer half-shells 1 and the other two in the inner block 2 so as to form two pairs, each of which is set "astride" of a controlled separation valve (Figures 4 to 6) .

The toroidal-sector piston β with circular cross section, is formed by the solid of revolution generated by the internal circumference of the chamber, which, in its motion about the main axis AP, describes a given characteristic angle designated by ^xλβ" in the figures.

According to the present invention, fixed on the piston are the tie-rods 7 that connect and fix it mechanically to the driving shaft 9, and seats are made for the corresponding circumferential piston rings 8. The tie-rods 7 are parallel to the driving shaft.

In this connection, it should be noted that fixing of the piston to the driving shaft can be performed also by means of welding or other known types of fixing. The driving shaft 9, which is basically tubular, is formed by the solid of revolution generated by the corresponding shape of Figure 2A-2B that describes an angle of 360° in its motion about the main axis AP, the base of which forms the top vault of the toroidal chamber. The circumferential sealing means are constituted by outer annular piston rings 10a, set between the external surface of the driving shaft 9 and the outer half-shells 1, and by inner annular piston rings 10b, set between the inner block 2 and the internal surface • of the driving shaft itself, the seats of said piston rings being made in the thickness of the driving shaft 9 (Figures 1 and 2A-2B, 3A-3B) .

The base 11 is fixed to the inner block 2 in order to form the top face of the chamber inside the inner block 2.

According to the invention, in the case of operation as ICE a further base is provided, designed to close the bottom part of the same inner block 2 so that the inner chamber will be closed to function as expansion box P.

Once again according to the invention, in the case of operation as tractor machine or worksite machine, instead of the second base there is provided a flange or other known means for connection to the intake manifold A.

In the first embodiment so far described purely by way of example, the characteristic angle a identified by the separation valves 4a and 4b is, for simplicity, equal to 180°. Consequently, the two outer half-shells 1 are semicircular.

In what follows, the separation valves 4a and 4b will also be designated by Cl and C2. OPERATION AS ICE

In its operation as ICE (Figures 8 to 13), the toroidal chamber is divided into two parts by the separation valves Cl and C2. As will be seen, these two parts house the volumes Sl, S2, S3 and S4, which correspond, respectively, to the: intake volume, compression volume, combustion volume, and scavenging/exhaust volume. More specifically, each of the volumes Sl to S4 has been numbered according to the nonreturn valve that enables it to exchange fluid to perform a given function: Sl is the volume of external air drawn in via the valve Vl from the rear face of the piston 6, which is then compressed on its front face to^' reach the volume S2 at the calibration pressure of the valve V2, via which said compressed air is sent to the expansion box, where it is preheated and pressurized further by absorbing heat from the engine and contributing to cooling thereof. In the volume S3 there occurs combustion of the air/fuel mixture, obtained by injecting fuel into the air coming from the expansion box via the valve V3, and the volume S4 contains the fumes to be exhausted via the valve V4. The four nonreturn valves Vl to V4 are preferably automatic and, in the case illustrated, the intake valve Vl and the discharge valve V4 communicate with the outside of the outer shell 1, whilst the valve V2 and the valve V3 communicate with the inner chamber of the inner block 2, which, as has been said, is closed and functions as expansion box P. It is important to note that, on the basis of the values of the angles α and β, it is possible to vary the amount of the volumes, whilst in the configuration adopted illustratively in Figures 8 to 13 (with α = β = 180°), the succession of the various steps is the following: the piston 6, represented in Figure 8 in the position where it has just uncovered the intake valve Vl, with its motion in a clockwise direction and the separation valve Cl closed, brings about a negative pressure, which causes the valve Vl to open and draws in fresh air into the volume Sl; simultaneously, the other face of the piston brings about an overpressure in the volume S4, which causes the discharge valve V4 to open, enabling evacuation of the combustion fumes. This step continues up to the position of Figure 9, when the piston 6 covers the discharge valve V4, which closes, whilst the separation valve Cl opens to enable passage of the piston itself, setting the volumes Sl and S4 in communication and thus putting an end to the negative pressure in the volume Sl and causing closing of the intake valve Vl.

Then the piston passes beyond the separation valve C2, which closes behind it, and subsequently uncovers the valve V3 (Figure 10) causing opening thereof and starting to take in from the expansion box P the compressed air that in the meantime has been preheated and then further pressurized, whilst in the volume S2 starts compression of the fresh air.

It is preferable to inject the fuel (for example, diesel oil) into the volume S3 by means of at least one injector set preferably on the inner block 1 in the proximity of the valves V3 and/or C2. In the case where said fuel requires sparking (such as, for example, petrol or alcohol or LPG or methane) , in a position corresponding to the injector there are also provided sparking means of a known type (for example, one or more spark plugs) .

In the figures, said injector and said spark plug have been designated as a whole by the reference I/C.

This step lasts until the piston 6 reaches the position of Figure 11, when, at the start of injection of diesel oil or upon sparking, according to the type of supply of the engine (for this reason in the figures an injector or spark plug designated by the reference I/C is represented) , the overpressure of the combustion (graphically represented in Figure 11 by a spark) will cause closing of the valve V3 and will start to transmit energy to the piston, whilst in the volume S2 compression of the air continues.

The latter will last until the piston has reached the position of Figure 12, when the air in the volume S2 exceeds the calibration pressure of the valve V2, which, by opening, enables access of the compressed air to the expansion box, whilst in the volume S3 the combustion (represented graphically in Figures 12 and 13 by a flame) develops and continues to push the piston 6.

The influx of compressed air from the volume S2 to the expansion box P is protracted until the piston covers the valve V2 causing it to re-close (Figure 13) , at the same time uncovering the valve V4, which reopens, thus starting evacuation of the fumes, the combustion in the volume S3 having in the meantime been completed.

At this point, the separation valve C2 reopens to enable passage of the piston 6, and as soon as the other face of the latter passes beyond the separation valve Cl, the latter re-closes behind it, thus restoring the situation immediately preceding that of Figure 8 and giving rise to a new cycle. OPERATION AS WORKSITE MACHINE The piston 6 supplies mechanical energy to the fluid that enters/exits from the volumes of the toroidal chamber.

In this case, the arrangement of the valves Vl to V4, preferably with automatic operation, is different from the preceding case and is the one indicated in Figures 14 to 17. More specifically, the intake valve Vl and the valve V3 communicate with the inner chamber of the inner block 2, whilst the delivery valve V2 and the valve V4 communicate with the outside of the outer shell 1.

In this case, the volumes Sl and S3 take in the fluid, whilst the volumes S2 and S4 carry out compression, so that, given the symmetry of operation with respect to the axis of the separation valves Cl and C2, the configuration α = β = 180° proves the most functional one.

In operation as worksite machine, the sequence of the steps is the following: the piston 6, represented in Figure 14 in the position where it has just uncovered the valve Vl, with its motion in a clockwise direction and the separation valve Cl closed, creates in the volume Sl a negative pressure, which causes the valve Vl to open, thus drawing in the fluid from the inner chamber, which in this case functions as intake manifold A. Simultaneously, the piston or plunger 6 compresses with its other face the fluid in the volume S4.

In this regard, it is to be noted that this action of the piston or plunger 6, in the case of incompressible fluid (operation as pump) causes opening of the valve V4, calibrated at the delivery pressure, whilst in the case of compressible fluid opening of the delivery valve V4 will occur when the piston or plunger 6 arrives, for example, in the position of Figure 15, when the pressure of the fluid in the volume S4 exceeds that of calibration of the delivery valve V4 (operation as compressor, fan or aspirator, according to calibration of the intake and delivery valves) .

This step continues up to the position of Figure 16, when the piston or plunger 6 covers the valve V4, which closes, whilst the separation valve Cl opens to allow the piston to pass, setting the volumes Sl and S4 in communication and thus putting an end to the negative pressure in the volume Sl, with the consequent closing of the valve Vl. As soon as the piston 6 passes beyond the valve V3

(Figure 17), with the separation valve C2 that closes behind it, a situation similar to that of Figure 14 will be set up, with the volume S3 instead of Sl and the volume S2 instead of ^• S4 : consequently, there is intake of new fluid in S3 and start of compression or thrust of the fluid previously drawn into the volume S2 out of the delivery valve V2. OPERATION AS TRACTOR MACHINE

The piston 6 receives mechanical energy from the fluid that enters/exits from the volumes of the toroidal chamber.

In this case, the arrangement of the valves Vl to

V4 remains unvaried with respect to the preceding case

(see Figures 18 to 21) , but the valves Vl and the V3 become controlled valves, with the volumes Sl and S3 that see to intake and expansion of the fluid with transmission of energy to the piston β, whilst the volumes S2 and S4 see to evacuation of the exhaust fluid.

Consequently, also in this case, given the symmetry of operation with respect to the axis of the separation valves, the configuration α = β = 180° is the most functional, with the following sequence of steps: as soon as the piston 6, in its motion in a clockwise direction, reaches the position indicated in Figure 18, with the separation valve Cl that has just closed behind it, the inlet valve Vl opens behind it, enabling inflow into the volume Sl of the fluid with high enthalpy and/or at a high pressure, which starts to transmit energy to the piston. Simultaneously, the piston or plunger 6 creates, with its front face, an overpressure in the volume S4, which causes opening of the discharge valve V4 enabling discharge of the fluid, which has now already undergone its enthalpy jump.

This step continues up to the position of Figure 19, when the controlled inlet valve Vl closes and the influx of the fluid with high enthalpy and/or at high pressure in the volume Sl ceases, whilst evacuation of the fluid from the volume S4 continues .

According to the invention, the volumetric pressures and the flow rates are such that the fluid in the volume Sl transmits energy to the piston 6 up to completion of its enthalpy jump, i.e., pushing the piston up to the position of Figure 20, when it covers the discharge valve V4, which that closes, whilst the separation valve Cl opens allowing it to pass. As soon as the piston passes beyond the inlet valve V3 (Figure 21) , with the separation valve C2 that closes behind it, a situation is set up similar to that of Figure 18, with the volume S3, instead of Sl, and the volume S2 instead of S4, with inflow of new fluid with high enthalpy and/or at a high pressure in the volume S3 and evacuation through the discharge valve V2 of the fluid in the volume S2, which has now completed its enthalpy jump.

At this point, it should be noted that the operation of the machine so far described, with particular reference to three cases of use of the invention has taken into consideration examples of constructional solutions limited to the main components. The attached drawings, in fact, are very schematic and do not include the well-known members for lubrication, cooling, and control of the valves, springs, etc. Furthermore, it is evident that the dimensions and the proportions illustrated have a purely illustrative and non-functional purpose. As it has been possible to see from the figures and from what has so far been described, the first embodiment of the invention, with two separation valves Cl and C2 arranged preferably, but not necessarily, at 180°, functions with a cycle that is completed in one turn of the driving shaft 9, i.e., describing a full cycle of 360°.

A second embodiment of the invention, illustrated in Figures 22 to 44 in three variants, one piston, two diametrally opposite pistons, and two pistons set close to one another, is characterized in that it envisages just one controlled separation valve Cl.

In this second embodiment, as will be seen, the apparatus that is described functions with a cycle that is completed in two turns of the driving shaft 9, i.e., describing two full cycles of 720°. In operation as ICE of the first variant of this second embodiment (Figures 22 to 30), the volumes Sl to S4, each of which is numbered according to the nonreturn valve that enable it to exchange fluid, perform different functions: the volume Sl draws in the external air that the volume S2 compresses up to the calibration pressure of the valve V2, and then sends it to the expansion box where it is preheated and pressurized further, thus absorbing heat from the engine and contributing to cooling thereof, whilst the volume S3 sees to combustion of the mixture, and the volume S4 sees to exhaust of the fumes.

In this case, the nonreturn valves Vl and V2 are automatic valves, whilst V3 and V4 are controlled.

In the configuration adopted, the piston or plunger 6 covers an arc of amplitude β = 90° approximately, and the succession of the various steps is the following: the^' piston 6, represented in Figure 22 in the position where it has just uncovered the valve Vl, with its motion in a clockwise^' direction and the separation valve Cl closed, creates a negative pressure that causes opening of the valve Vl and draws in fresh air into the volume Sl, whilst a purposely- provided control device prevents opening of the valve V3. Simultaneously, the piston 6 creates with its other face an overpressure in the volume S4, which causes opening of the valve V4 in so far as a purposely provided control device enables opening thereof, thus enabling evacuation of the combustion fumes.

This step continues up to the position of Figure 23, when the piston 6 covers the valve V4, which closes, whilst the separation valve Cl opens to allow the piston to pass, setting in communication the volumes Sl and S4, thus putting an end to the negative pressure in the volume Sl and causing closing of the valve Vl . Then the piston 6, after a step in which it entrains the air drawn in trapped between its two faces

(Figure 24), passes beyond the separation valve Cl, which will close behind it, until V3 is uncovered (see

Figure 25) , causing opening thereof, in so far as the device that controls it carries out release thereof. There thus starts introduction from the expansion box P of the compressed air that in the meantime has been preheated and further pressurized, the pressure of which keeps the valve Vl closed, whilst in the volume S2 there starts compression of the fresh air, with the control device of the valve V4, which blocks it in the closed position.

This step lasts until the piston reaches the position of Figure 25, when the fuel is injected into the volume S3 via at least one purposely provided injector, set, preferably, on the inner block 1 in the proximity of the valves V3 and/or Cl. In the case where the fuel requires sparking (petrol, LPG, methane, etc.), provided in the proximity of the injector are also ignition means, such as for example a spark plug._. In the figures, said injector/spark plug is designated by the reference I/C.

At the start of injection of the fuel with self- ignition (for example, diesel oil) or upon sparking (for example, petrol or LPG) , the overpressure of combustion (represented graphically in Figure 26 by a spark) will cause closing of the valve V3 and will start to transmit energy to the piston, whilst compression of the air continues in the volume S2.

Said compression will last until the piston has reached the position of Figure 27, when the air in the volume S2 exceeds the calibration pressure of the valve V2, which, by opening, enables access of the compressed air to the expansion box P, whilst in the volume S3 the combustion (represented graphically in Figure 27 and 28 by a flame) develops and continues to push the piston.

The inflow of compressed air from the volume S2 to the expansion box P is protracted until the piston β covers the valve V2, causing it to re-close (Figure 28), whilst the separation valve Cl reopens to enable passage of said piston.

At this point, there will be a step of conveying of the fumes, trapped between the two faces of the piston (Figure 29) , which is protracted until the piston again uncovers the valve V4, which reopens, because the control device will have seen to releasing it, thus starting evacuation of the fumes.

As soon as the piston passes beyond Cl again (Figure 30), it re-closes behind it, in this way restoring the situation immediately preceding that of Figure 22 and giving rise to a new cycle. With reference to Figures 31 to 37, corresponding to a variant of the second embodiment, which envisages two pistons arranged at an angle γ = 180° from one another, we shall now analyse the case of operation as ICE. It should be noted that, even though the figures referred to illustrate an example of embodiment in which the two pistons 6 are the same as one another, they can have different lengths without thereby modifying operation of the entire apparatus, which will now be described.

Also in this case, the volumes Sl to S4, each of which is numbered according to the nonreturn valve that enables fluid exchange, perform different functions: the volume Sl draws in the external air that the volume S2 compresses up to the calibration pressure of the valve V2 and then sends it to the expansion box, where it is preheated and pressurized further thus absorbing heat from the engine and contributing to its cooling, whilst the volume S3 sees to combustion of the mixture and the volume S4 to exhaust of the fumes; in addition, the four nonreturn valves Vl and V2 are automatic valves, whereas the valves V3 and V4 are controlled.

In the configuration adopted (β = 45° approximately, γ = 180°), the "-succession of the various steps is the following: a piston 6, represented in Figure 31 in the position where it has just uncovered the valve Vl, with its own motion in a clockwise direction and the separation valve Cl closed, creates a negative pressure, which causes opening of the valve Vl and draws in fresh air into the volume Sl, whilst a purposely provided control device prevents opening of the valve V3. Simultaneously, the other piston 6 causes an overpressure, which pressurizes the air previously drawn in and contained in the volume S2, with the valve V4 that is kept closed by a purposely provided control device.

In this step, there will also be conveying of the fumes, trapped between the two pistons 6, into the volume S4.

This step continues up to the position of Figure 32, when the air in S2 exceeds the calibration pressure of the valve V2, which, by opening, enables access of the compressed air to the expansion box P.

Then, the piston 6 that compressed the air in the volume S2 covers the valve V4 , which closes, whilst the separation valve Cl opens to allow the piston to pass, setting in communication the volumes Sl and S4, thus putting an end to the negative pressure in the volume Sl and causing closing of the valve Vl (Figure 33) .

After a step in which the air drawn in is entrained, trapped in the volume Sl, the piston that compressed the air in the volume S2 passes beyond the separation valve Cl, which will close behind it, thus giving rise also to evacuation of the combustion fumes in the volume S4, via the valve V4, which has been released by the corresponding control device. Said piston 6 proceeds until V3 is uncovered (Figure 34), causing opening thereof, which is now enabled by the release effected by the device that controls the valve V3.

There thus starts introduction from the expansion box P of the compressed air that in the meantime has been preheated and further pressurized, the pressure of which will keep the valve Vl closed, whilst in the volume S4 evacuation of the fumes starts via the valve V4. This step lasts until the piston reaches the position of Figure 35, when the fuel is injected into the volume S3 via at least one purposely provided injector set, preferably, on the inner block 1 in the proximity of the valves V3 and/or Cl. In the case where the fuel requires sparking (petrol, LPG, methane, etc.), provided in the proximity of the injector are also ignition means, such as for example a spark plug. In the figures, said injector/spark plug is designated by the reference I/C. At the start of injection of the fuel with self- ignition (for example, diesel oil) or sparking (for example, petrol or LPG) , the overpressure of the combustion (represented graphically in Figure 35 by a spark) will cause closing of the valve V3 and will start to transmit energy to the piston 6 (Figure 36) , whilst in the volume S4 evacuation of fumes by the second piston continues .

This step of combustion will last until the piston has reached the position of Figure 37, with the combustion (represented graphically in Figure 36 and 37 by a flame) that has been completed in the volume S3, transmitting energy to the piston 6 so that the separation valve Cl is re-opened to enable passage of the second piston.

At this point, there will be a step of conveying of the fumes, trapped in the volume S4 between the two pistons 6, which is protracted until the second piston that is not in contact with the combustion passes beyond the valve Cl, which re-closes behind it, in this way restoring the situation immediately preceding that of Figure 31 and giving rise to a new cycle.

In the further variant illustrated in Figures 38 to 44, the operation of the invention as two-piston ICE is altogether similar to what has just been described.

Illustrated here is the possible operation in the case where the angle γ between the two pistons 6 is different from 180°.

As has already been said previously, the two pistons 6 could have an angular amplitude β different from one another. Finally, a third embodiment of the invention, illustrated in Figures 45 to 48, is characterized in that it envisages one piston 6, just one controlled separation valve Cl and just two nonreturn valves Vl and V2. In this case, as will be seen, operation as tractor machine/worksite machine is altogether similar to what has been described for the first embodiment with two separation valves and four nonreturn valves, with the only difference that steps are envisaged in which the working fluid is entrained between the faces of the piston, as may be readily appreciated from the figures.

More specifically, in operation as tractor machine (Figure 45 to 48) the volumes Sl and S2, each of which is numbered according to the nonreturn valve that enables it to exchange fluid, perform different functions: the volume Sl sees to intake of the fluid at high enthalpy and/or high pressure from the intake manifold and expansion thereof with transmission of energy to the piston, whilst the volume S2, via the valve V2, sees to exhaust of the fluid that has now performed its enthalpy jump; in addition, the nonreturn valve V2 is automatic, whereas the valve Vl is controlled with the succession of the steps described hereinafter. When the piston reaches the position of Figure 45, the device that controls the valve Vl actuates opening thereof. There thus starts, in the volume Sl of the toroidal chamber, inflow of fluid at high enthalpy and/or pressure, which, with the separation valve Cl closed, starts to transmit energy to the piston 6, whilst the latter simultaneously^" causes with the other face an overpressure in the volume S2, which brings about opening of the valve V2, giving rise to discharge of the fluid that has now performed its enthalpy jump. This step continues up to the position immediately subsequent to that of Figure 46, when the valve Vl is closed by the corresponding control device. Then in the volume Sl expansion of the fluid proceeds, simultaneously with evacuation of the exhausted fluid in the volume S2 until the piston 6 reaches the position of Figure 47, when it covers the valve V2, which closes, whilst the separation valve Cl opens to enable passage of the piston.

Next, the piston or plunger 6, after a step in which it entrains the exhausted fluid trapped between its two faces (Figure 47), passes again, with its rear face, beyond the separation valve Cl, which will close behind it, until the valve Vl is uncovered again, in this way restoring the situation immediately prior to that of Figure 45 and giving rise to a new cycle. With reference to the same Figures 45 to 48, in operation as worksite machine, instead, the volumes Sl and S2, each of which is numbered according to the nonreturn valve that enables it to exchange fluid, perform different functions: the volume Sl sees to intake of the fluid to be compressed, whilst the volume S2 sees to compression and delivery; in addition, the nonreturn valves Vl and V2 are automatic, with the succession of the steps described hereinafter.

The piston or plunger 6, represented in Figure 45 in the position where it has just uncovered the valve Vl, with its motion in a clockwise direction and the separation valve Cl closed, brings about a negative pressure, which causes opening of the valve Vl and draws in fresh air into the volume Sl; simultaneously with the other face it causes a compression in the volume S2, which, in the case of operation as pump (incompressible fluid) will cause opening of the valve

V2, calibrated at the delivery pressure, whilst in the case of operation as compressor (compressible fluid) opening of the valve V2 will occur, for example, when the position of Figure 46 is reached.

This step continues up to the position of Figure 47, when the piston 6 covers the valve V2, which closes, whilst the separation valve Cl opens to enable passage of the piston itself, setting in communication the volumes Sl and S2, thus putting an end to the negative pressure in Sl and bringing about closing of the valve Vl.

^•Then the piston 6, after a step in which it entrains the fluid drawn in trapped between its two faces (Figure 48) , passes again, with its rear face, beyond the separation valve Cl, which will close behind it, thus restoring the situation immediately prior to that of Figure 45 ^"and giving rise to a new cycle.

In conclusion, it should be noted that herein the invention has been described hypothesizing that the discharge of the fluid is performed towards the outside and the intake is performed from inside, but it is clear that the machine could function also arranging the intake and exhaust in the opposite way. The present invention has been described and illustrated in some of its preferred embodiments and variants, but- it is clear that modifications and/or replacements that are technically and/or functionally equivalent may be made by any person skilled in the branch, without thereby this implying any departure from the sphere of protection of the present industrial patent right,

Claims

1. A volumetric apparatus usable as internal- combustion engine (ICE) or as worksite machine or as tractor machine, characterized in that it comprises, in combination: a toroidal chamber, with one or more controlled separation valves (4a, 4b, Cl, C2) that identify a characteristic angle on the circumference of revolution of the torus that defines said chamber, each of which valves is designed to be opened, when it is about to be reached by at least one toroidal-sector piston or plunger (6) that turns within the chamber itself, so as to allow the piston to pass, and to be closed as soon as said piston (6) passes beyond it, dividing the chamber into at least two parts designed to house volumes of fluid (Sl to S4) having different functions, the variability of which enables exchange of energy between a working fluid and the piston (6); each of the aforesaid sections (Sl to S4) being delimited by the wall of a closed separation valve (4a, 4b, Cl, C2) or of a piston and by the wall that faces it, whether it belongs to the same piston or to another piston (6) or else to another separation valve (4b, 4a, C2, Cl) ; each of said one or more arched pistons or plungers (6) being mechanically constrained to a driving shaft (9) set coaxial to the main axis (AP) that coincides with the axis of revolution of the torus that defines the chamber in which the piston (6) slides.

2. The apparatus according to Claim 1, characterized in that said toroidal chamber and said piston or plunger (6) have a circular or elliptical cross section or in any case a closed cross section.

3. The apparatus according to Claim 1, characterized in that it basically comprises:

A. two outer half-shells (1) designed to be assembled for providing an annular body, each of which is basically formed by an arched body with development according to the arc of a circle, having the concave side provided with a toroidal groove and the ends provided with flanges (I' ) for mutual fixing to the other half-shell;

B. an inner block ,(2) designed to be enclosed between said half-shells (1) , having a basically annular body with the outer side provided with a toroidal groove mated to those of the half-shells themselves to form said toroidal chamber, which has a circular or elliptical cross section or in any case a closed cross section;

C. at least one piston or plunger (6) having a toroidal-sector body with circular or elliptical cross section, designed to slide within the toroidal chamber;

D. one or more separation passing valves (4a, 4b, Cl, C2) , each of which is constituted basically by a diaphragm that slides crosswise with respect to said toroidal chamber and which are designed to be controlled in a known way for closing/opening the chamber itself to the passage of the piston (6);

E. at least two nonreturn valves (Vl to V4), either automatic or controlled, for regulating the inlet/outlet of fluid into/from the toroidal - chamber; F. a driving shaft (9), having a basically cylindrical tubular shape which shares the main axis (AP) of the toroidal chamber in which the piston (6) slides; G. circumferential sealing means (10a and 10b) , set respectively between the driving shaft (9) and the outer half-shells (1) and between the driving shaft (9) and the inner block (2);

H. at least one circular base (11) , designed to close an inner chamber delimited by the empty space within the annular body of the inner block (2), the base of which is set on the same side as the driving shaft (9) .

4. The apparatus according to the preceding claim, characterized in that each of the two outer half-shells (1) is formed by the solid of revolution generated by an appropriate shape that describes an angle respectively equal to α and 360 °-α in its motion about the main axis (AP) . 5. The apparatus according to the preceding claim, characterized in that at least one of the ends of said half-shells (1) , parallel to the axis of revolution or main axis (AP) , has a height greater than the rest of the annular body and is formed by the solid of revolution generated by an appropriate shape that describes an angle of a few degrees, thus constituting outer half-flanges (I' ) for mutual fixing of the half- shells (1) themselves.

6. The apparatus according to the preceding claim, characterized in that made within at least one of the half-flanges {!' ) are: holes for tie-rods (3) designed to keep the apparatus assembled, and half of the seats within which said one or more controlled separation valves (4a, 4b, Cl, C2) slide.

7. The apparatus according to Claim 3, characterized in that said inner block (2), enclosed between the outer half-shells (1) to form said toroidal chamber with circular or elliptical cross section, is formed by the solid of revolution generated by an appropriate shape that describes an angle of 360° in its motion about the main axis (AP) .

8. The apparatus according to Claims 5 and 7, characterized in that in a position corresponding to the half-flanges (I' ) of the outer shells (1) , the inner block (2) is provided with purposely provided counterflanges (2^r ) formed by transverse elements with axial development, designed to co-operate with the half-flanges (I' ) of the outer half-shells (1) .

9. The apparatus according to the preceding claim, characterized in that said counterflanges (2' ) form an enlarged portion made in which are the remaining half of the seats, within which the one or more controlled separation valves (4a, 4b, Cl, C2) slide.

10. The apparatus according to Claim 3, characterized in that the annular body of the inner block (2) comprises a central cavity or inner chamber, which, in the case of operation as ICE, is designed to constitute an expansion box (P) of the apparatus.

11. The apparatus according to Claim 3, characterized in that the annular body of the inner block (2) comprises a central cavity or inner chamber that, in the case of operation as tractor machine or worksite machine, is designed to constitute the terminal part of an intake manifold (A) for the working fluid. 12. The apparatus according to Claim 3, characterized in that each of the controlled separation passing valves (4a, 4b, Cl, C2) , is constituted by the solid of revolution generated by an appropriate shape that describes an angle of a few degrees in its motion about the main axis (AP) ; said separation valves being designed to slide between a position of bottom dead centre (4a), with a motion such as ^' to enable passage of the piston (β), to a position of top dead centre (4b), in such a way as to close the toroidal chamber before and after passage of the same piston (6), and vice versa.

13. The apparatus according to the preceding claim, characterized in that each of said controlled valves (4a, 4b, Cl, C2 ) is constituted by a sliding diaphragm provided with a through opening in a position corresponding to the cross section of the toroidal chamber within which said at least one piston or plunger (6) slides.

14. The apparatus according to Claim 3, characterized in that said nonreturn valves (Vl to V4) for inlet/outlet of fluid into/from the toroidal chamber are automatic, with opening/closing determined by the pressure of the fluid and by the calibration pressure, or else controlled in a known way. 15. The apparatus according to the preceding claim, characterized in that at least one of the seats (5,) for said nonreturn valves (Vl to V4) is made in the outer half-shells (1) and at least one of the seats (5) for said nonreturn valves (Vl to V4) is made in the inner block (2) ; said at least two seats (5) for the nonreturn valves being arranged so as to form pairs, each of which is set "astride" of a controlled separation valve (Cl, C2) .

16. The apparatus according to Claim 4, characterized in that each toroidal-sector piston (6), is formed by the solid of revolution generated by the internal circumference of the chamber, which, in its motion about the main axis (AP) , describes a given angle β .

17. The apparatus according to Claim 3, characterized in that fixed on each piston (6) are tie- rods (7) that connect and fix it mechanically to the driving shaft (9), and in that provided in the proximity of its ends are seats for corresponding circumferential sealing piston rings (8); the tie-rods (7) being parallel to the driving shaft (9) .

18. The apparatus according to Claim 3, characterized in that the driving shaft (9), which is basically tubular, is formed by the solid of revolution generated by an appropriate shape that describes an angle of 360° in its motion about the main axis (AP), the base of which forms the top vault of the toroidal chamber.

19. The apparatus according to Claim 3, characterized in that said circumferential sealing means are constituted by outer annular piston rings (10a) , set between the external surface of the driving shaft (9) and outer half-shells (1), and by inner annular piston rings (10b) , set between the inner block (2) and the internal surface of the same driving shaft, said seats being made in the thickness of the tubular body of the driving shaft (9) .

20. The apparatus according to the preceding claim, characterized in that the base (11) is fixed to the inner block (2) in order to form the top face of the chamber inside the inner block (2) . 21. The apparatus according to the preceding claim, characterized in that provided, in the case of operation as ICE, is a further base, designed to close the bottom part of the same inner block (2) so that the inner chamber is closed to function as expansion box (P).

22. The apparatus according to Claim 20, characterized in that, in the case of operation as tractor machine or worksite machine, fixed to the bottom part of the same inner block (2) is a flange or other known means for connecting the inner chamber to an intake manifold (A) .

23. The apparatus according to Claim 3, characterized in that said pistons (6) have lengths different from one another. 24. The apparatus according to Claim 3, characterized in that said pistons (6) are fixed to the driving shaft (9) and are arranged in the toroidal chamber at an angular distance Y < 180°.

^'25. The apparatus according to Claim 3, characterized in that it envisages four nonreturn valves (Vl to V4) arranged in pairs, so that one pair sets in communication the toroidal chamber with the outside world and the other pair sets the same toroidal chamber in communication with the chamber inside the block (2) ; each pair of nonreturn valves being set "astride" of a separation valve (Cl, C2) different from that of the other pair.

26. The apparatus according to Claim 3, characterized in that it envisages four nonreturn valves (Vl to V4) arranged in pairs, so that the valves of each pair set the toroidal chamber in communication both with the outside world and with the chamber inside the block (2); each pair of nonreturn valves being set "astride" of a separation valve (Cl, C2) different from that of the other pair. 27. The apparatus according to Claim 3, characterized in that it envisages four nonreturn valves (Vl to V4) arranged in pairs, so that one pair sets the toroidal chamber in communication with the outside world and the other pair sets the same toroidal chamber in communication with the chamber inside the block (2); said pairs of nonreturn valves being set "astride" of one and the same separation valve (Cl, C2) .

28. The apparatus according to Claim 3, characterized in that it envisages two nonreturn valves

(Vl, V2) and one separation valve (Cl) ; said valves setting the toroidal chamber in communication both with the outside world and with the chamber inside the block

(2) and being arranged on opposite sides with respect to said separation valve (Cl) .

29. The apparatus according to Claim 3, characterized in that, provided in the proximity of the nonreturn valve (V3) are means for delivery of the fuel into the volume (S3) .

30. The apparatus according to the preceding claim, characterized in that in the proximity of the valve (V3) there are further provided means for ignition of the fuel present in the volume (S3) .