MXPA99001391A - Improvements in axial piston rotary engines - Google Patents

Abstract

A rotary internal combustion engine (200) of the type having a rotor assembly (216) supported in a housing (210) for rotation about a longitudinal axis (217), said housing having two spaced apart end plates (212, 213) and said axis being the axis of rotation of an output shaft (218) operatively connected at one end to said rotor assembly, the other end being free and passing through an aperture in one of said end plates, said rotor assembly including a plurality of pistons (231 to 238) mounted for reciprocating movement in respective cylinders (228) arranged in spaced relation around said longitudinal axis, and cam follower means (254) operatively connected to each piston and adapted to coact with undulating cam track means (225) supported around said axis of rotation and between said end plates, means (215) being provided for conveying combustible fuel to, and for conveying exhaust gases from the operative ends of the cylinders whereby cyclical combustion of said fuel in said cylinders imparts reciprocation to said pistons with resultant thrust against said cam track means so as to cause rotation of said rotor assembly (216) and output shaft (218);characterised in that said undulating cam track means includes an annular track mounted to a support stem or shaft (219) disposed substantially centrally thereof and extending in the direction of said longitudinal axis, said support stem or shaft being supported at one end by the other of said end plates (213) and the axis of said annular cam track means being the axis of rotation of said rotor assembly.

Description

IMPROVEMENTS IN AN AXIAL PISTON ROTATING ENGINE TECHNICAL FIELD OF THE INVENTION The present invention relates to improvements in rotary engines with axial pistons and has particular, but not exclusive, application to improvements in or modifications to the type of engine described in general principles in International Patent Application Number PCT / AU95 / 00815 (to which in what follows will be referred to as "PCT application").

BACKGROUND OF THE INVENTION In said PCT application very useful forms of rotary engines with axial pistons were described and illustrated, as is evident especially in the drawing of the assembly of Figure 11 of said application, and it should be understood that all the disclosures of the memory Descriptive of that request should be considered as part of the disclosure of the present specification to the extent that they are relevant and / or convenient. In such engines, a plurality of pistons are mounted on cylinders as part of a rotor assembly, the pistons cooperating with a driving track to cause rotation of the rotor assembly when combustion of fuel in the cylinder occurs in a typical manner of the engines internal combustion type piston. In the present specification the terms "upper end" and "lower end" are used to refer to the combustion end and the driving end of the engine, as will be understood by those skilled in internal combustion engines of the piston type. An object of the present invention is to provide a rotary engine with axial pistons of the general type described in said PCT application, in which the thrust on the seals of the inlet and / or outlet mouth is reduced. Still another object of the present invention is to provide a rotary engine with axial pistons of the general type described in said PCT application, in which the lower end of the motor is sealed from the upper end, so that it can avoid or at least substantially prevent the lubricant required for the driving track, the follower of the driving track, the walls of the cylinder and other components of the lower end enter the combustion chamber by means of the inlets. It has long been known that the regulation of the opening and closing of the inlet and exhaust ports has a significant effect on the operation of internal combustion engines and that the performance of internal combustion engines can be increased by varying the regulation. , in particular the opening regulation of the inlet ports in operation. Therefore, an object of the present invention is to provide a rotary motor with axial pistons of the general type described in said PCT application that lends itself to variable regulation of the input. Still another object of the present invention is to provide a rotary engine with axial pistons that lends itself to variable length piston strokes to vary the compression ratio, whereby different fuels can be efficiently used.

DESCRIPTION OF THE INVENTION Taking into account the foregoing objectives and other objectives, the present invention, in one aspect generally refers to a rotary internal combustion engine of the type having a rhetorical assembly supported in a housing for rotation about a geometric axis longitudinal, said housing having two end plates spaced apart and said axis being the axis of rotation of an output shaft operatively connected to one end of said rotor assembly, the other end being free and passing through an opening in a of said end plates, said rotor assembly including a plurality of pistons mounted for reciprocating movement in respective cylinders disposed in spaced relation about said longitudinal axis and follower elements operatively connected to each piston and adapted to act together with the undulating driving track element. supported around said rotation axis and between said end plates, providing elements to carry fuel to, and to carry exhaust gases from the operating ends of the cylinders, whereby the cyclic combustion of said fuel in said cylinders can impart reciprocating movement to said pistons with resultant thrust against said driving track element. , so that the rotation of said rotor assembly and output shaft occurs; characterized in that said undulating driving track element includes an annular track mounted to a rod or support shaft disposed substantially centrally therein and in the direction of said longitudinal axis, said rod or support shaft being supported at one end by the other of said end plates and the geometric axis of said annular driving track element being the geometric axis of rotation of said rotor assembly. In another aspect the invention relates in general to a rotary internal combustion engine of the type having a rotor assembly supported in a housing for rotation about a longitudinal axis, said housing having two end plates spaced apart from each other and said axis being the axis of rotation of an output shaft operatively connected to one end of said rotor assembly, the other end being free and passing through an opening in one of said end plates, said rotor assembly including a plurality of pistons mounted for movement reciprocating in respective cylinders disposed in spaced apart relation about said longitudinal axis and follower elements operatively connected to each piston and adapted to act together with the undulatory driving track element supported around said rotation axis and between said end plates, provides components for carrying fuel to and to carry exhaust gases from operating ends of the cylinders, whereby cyclical combustion of said fuel in said cylinders can impart reciprocating movement to said pistons with resultant thrust against said driving track element, so that the rotation of said rotor assembly and output shaft occurs; characterized in that said plurality of pistons are arranged in two or more assemblies, each assembly having two or more pistons arranged in spaced relation about said rotation axis and interconnected by means of piston connecting elements, so that the pistons of each the assembly moves in unison, said undulatory driving track follower element and said undulating driving track element arranged so that the direction of travel of one set of pistons is generally opposite to the direction of another set of pistons and that said element The undulating driving track includes an annular track mounted to a rod or support shaft disposed substantially centrally therein and in the direction of said longitudinal axis, said rod or support shaft being supported at one end on the other of said end plates. and the geometric axis of said driving track element being ular the geometric axis of rotation of said rotor assembly. In yet another embodiment, the invention relates in general to a rotary internal combustion engine of the type having a rotor assembly supported in a housing for rotation about a longitudinal axis, said housing having two end plates spaced apart from each other and said geometric axis, the geometric axis of rotation of an output shaft operatively connected to one end of said rotor assembly, the other end being free and passing through an opening in one of said end plates, said rotor assembly including a plurality of pistons mounted for reciprocating movement in respective cylinders arranged in spaced relationship about said longitudinal axis and followers connected operatively to each piston and adapted to act together with the undulating driving track element supported around said rotation axis and between said end plates , providing elements to carry fuel to, and to carry exhaust gases from operating ends of the cylinders, whereby the cyclic combustion of said fuel in said cylinders can impart reciprocating movement to said pistons with resultant thrust against said driving track element, so that the rotation of said rotor assembly and output shaft occurs; characterized in that said plurality of pistons are arranged in two or more assemblies, each assembly having two or more pistons arranged in spaced relation about said rotation axis and interconnected by means of piston connecting elements, so that the pistons of each assembly they move in unison, said undulatory driving track follower element and said undulating driving track element arranged so that the direction of travel of one set of pistons is generally opposite to the direction of another set of pistons and that each of said piston connecting elements includes a ring disposed around said rod or support shaft, and said ring connecting a set of pistons is displaceable with reciprocating movement within a ring connecting another set of pistons. Preferably, said cylinders are provided in a cylinder block and said rod or support shaft is coaxial with said output shaft and rotatably supports said cylinder block. It is also preferred that said output shaft be operatively connected to said cylinder block by means of an output plate assembly, said cylinder block and said output plate assembly as a whole defining a chamber of circular cross-section generally around said longitudinal geometric axis and said driving track element, and said driving track follower element being housed inside said chamber. Preferably, said rod or support shaft is supported at its other end (the end of said chamber) by said output shaft or said output plate assembly. It will be appreciated that in such a form of the invention, the extreme thrust will be substantially reduced, if not eliminated. Preferably, said cylinder block is supported in a sealable manner by said support shaft or shaft, and said outlet plate assembly is sealably connected to said cylinder block, allowing such sealing that oil or other lubricant is retained in said chamber. for lubricating the driving track element and the driving track follower element, the cylinder walls and other lower end components as will be more clearly understood in the description of the drawings without significant leakage of lubricant to the operating ends of the cylinders (or in other words, the combustion chambers). Preferably, said driving track element is pivotally supported by said other end plate, whereby it can be pivoted or rotated to vary the angular position of the driving track element relative to said other end plate. Typically, the element for carrying fuel to, and / or exhaust gases from, the operating ends of the cylinders will influence ports provided in said other end plate and it will be appreciated that the angular movement of the driving track element will vary the input regulation and / or escape. Also, in embodiments where surface sealing elements are used to seal the inlet / exhaust mouth of the cylinders, as will be understood in the embodiments illustrated in the drawings, the reduction in thrust and end mentioned above will reduce loads on such sealing elements. , thus allowing an improved seal. Furthermore, it is preferred that said corrugated driving track element be movable toward and away from said other end plate in the direction of said longitudinal axis. Properly, such movement allows the stroke of the pistons to be varied, thereby varying the compression ratio of the engine. In this way, the engine includes suitable elements to supply fuel to the cylinders, and different fuels can be used as desired. As described above, the plurality of pistons according to the second aspect of the invention are arranged in two or more assemblies, each assembly having two or more pistons arranged in spaced relation around said rotation axis and interconnected by means of connecting elements of the pistons, so that the pistons of each set move in unison, said drought element being of the driving track and said undulating driving track element arranged so that the direction of travel of a set of pistons is generally opposite to the direction of another set of pistons. In a preferred form of the invention, there are two sets of pistons arranged, so that one assembly generally moves in the direction opposite to the displacement of the other set, although there may be an overlap with the limit switches when both sets are displaced momentarily in the same direction. Likewise, it is preferred that each set include four, six or eight pistons arranged, so that alternating pistons are in the drive stroke, while the other pistons are in the intake (or induction) stroke. It is also preferred that the connecting elements of each set of pistons be constituted by a continuous ring arranged around said rod or support shaft, with a ring arranged so that it moves with reciprocating movement within the other ring. Each of said rings must be of sufficient strength to maintain all the pistons of the assembly moving in unison, although it is possible that one set of pistons is disposed at a greater radius of said longitudinal axis than the other set of pistons and that they act in conjunction with different driving track elements, it is preferred that each set of pistons be arranged equidistantly of the longitudinal axis, whereby all assemblies can act together with the same driving track element. In other forms of the invention, in which more than two piston assemblies are used, it is preferred that they be arranged in pairs, each pair acting with the same driving track element. While it will be understood that the torque could be transferred from the pistons directly to the cylinder walls, it is preferred that the engine include torque transfer elements to transfer the torque of each piston to said output shaft, such being torque transfer elements arranged so as to prevent the pistons from "tapping" on their respective cylinders or rubbing on the cylinder walls, thereby reducing wear. Also, it is preferred that the torque transfer element be effective to maintain the pistons centrally in their respective cylinders. In a preferred form, the torque transfer element transfers the torque from the piston connecting elements directly to the cylinder block which in turn is fixed to the output plate assembly. In an embodiment in which the piston connecting elements are constituted by a continuous ring, the torque transfer element includes a ammunition rotatably captured in part in a recess provided in said ring and partly in a recess provided in said block. cylinders and / or said outlet plate assembly. However, in other embodiments, the torque transfer member includes a linear guide shaft that runs from the cylinder block and the output plate assembly and is fixed thereto and a linear bearing assembly slidably mounted on it. said linear guide shaft and fixed to the ring. In order that the invention may be more readily understood and practically implemented, reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention, by way of illustration and example only, and are not to be construed in any way as limiting The invention disclosed and claimed herein, upon which, the aforementioned objects and advantages and others of the present invention will become more clear to those of ordinary skill in the art.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows diagrammatically or schematically in diametral cross section or elevation an engaccording to the invention with parts omitted for simplifying purposes.

Figure 2 schematically shows diametral cross section or raised another motor according to the invention with parts omitted for simplifying purposes. Figure 3 is a diagrammatic plan view of a motor of the general type shown in Figure 1 showing that two ring assemblies annular connectors can be used to carry two sets of pistons acting in conjunction with previously separated tracks according to the invention, the diagrammatic plan view illustrating the torque transfer element described in relation to Figures 1 and 2. Figure 4 is a diagrammatic plan view of a motor of the general type shown in Figure 1 showing how two sets Ring-shaped annular connectors can be used to carry two sets of pistons coacting with the same driving track according to the invention, the diagrammatic plan view illustrating the torque transferring element described in relation to Figure 6. Figure 5 is a sectional view of a motor according to the invention showing more details of various components. Figure 6 is a sectional view of another engaccording to the invention using an alternative torque transference element to that of the engof Figure 5.

. DETAILED DESCRIPTION OF THE DRAWINGS The eng200 illustrated in Figure 1 includes a housing that is indicated generically with the reference number 210, which comprises a cylindrical shell 211 sealably connected to and between circular end plates spaced apart from each other. are an output or drive end plate 212, and an induction / exhaust end plate 213, plate 213 having inlet ports 206 and 207 (not shown) and exhaust ports 208 and 209 for gas inlet and exhaust of combustion, as well as adequate supplies of spark plugs or incandescent spark plugs (not shown). A rotor assembly 216 is mounted within the housing 210 for rotation about a longitudinal axis 217 that passes centrally in general through the housing and the two end plates, the rotor assembly being supported in the housing by the coaxial output shaft 218 and the driving shaft supporting shaft 219, the free ends of which pass through the drive end plate 212 and the induction end plate 213, respectively, as will be described in greater detail below, with the output shaft being mounted on the output shaft. a bearing 220 and having a seal 220a mounted on the drive end plate. The non-free or internal ends 221 and 222 of the output shaft and the support shaft of the driving track, respectively, are arranged in almost abutting relationship, the supporting shaft of the driving track being rotatably supported by the output shaft. For this purpose, a bearing 223 is mounted in a recess 223a formed at the end of the output shaft. In this embodiment, the supporting axis of the driving track is shown under pressure with the induction end plate and the keyed thereto to prevent relative rotation. However, if longitudinal or pivotal movement is required to change the compression ratio or vary the input regulation, as will be more readily understood below, a suitable mounting block can be mounted on the outer face of the induction end plate. In the embodiment shown in Figure 5, the support shaft of the driving track has a spl325 thereon which may be a reinforcing plate 325a which in turn is ablated to the induction endplate. In addition, it will be appreciated that the recess 223a is replaced by a recess 323a provided in the support shaft 319 of the driving track and the output shaft has a short shaft or pin 318a., which is rotatably mounted in a bearing 323 fixed in the recess. Near its internal end a disc-like portion 224 is formed integrally with the axis of the driving track and is arranged radially therefrom, having at its periphery an undulating driving track 225 which is sinusoidal in general in the direction of the longitudinal geometric axis, whose purpose will be evident below. The rotor assembly includes a cylinder block 227 that has eight cylinders 228 equally spaced apart from each other therein and that are at the same radius from the longitudinal axis 217. The intake and exhaust gases enter and leave the cylinders through of a cylinder boc 215 that moves in and out of alignment with the inlet ports 206 and 207 and the exhaust ports 208 and 209. The manner in which the seal is maintained between the cylinder mouth 215 and the end plate induction / exhaust is the same as that described in said PCT application. The pistons 231 to 238 are disposed so as to reciprocate in one of the cylinders 228 parallel to the longitudinal geometrical axis, four of the pistons being mounted in an internal piston connecting ring assembly 241, the four pistons being alternated mounted on an external piston connecting ring assembly 242, as shown more clearly in Figures 3 and 4. It will be understood that the use of rings to connect the set of pistons allows one or two sets of pistons to act in conjunction with a driving track and other sets act in conjunction with one or more diverting tracks disposed radially outward of the other track. The embodiment illustrated in Figure 2 is the same as that illustrated in Figure 1, except that the pistons are mounted in respective star mounting plates 243 and 244 (not shown), respectively. A hole 246 passes through the cylinder block coaxially with the longitudinal axis 217 to receive therein the support shaft 219 of the driving track, the rotor assembly being supported by means of the cylinder block for rotation about the support shaft of the driving track. For this purpose, a bearing 247 is mounted in the hole 246 ~ and is seated on a shoulder 248 formed on the support shaft of the driving track. In the embodiments of Figures 5 and 6, an additional bearing 347a is provided in the hole adjacent to the disc-like portion 324. The output shaft 218 is connected to the rotor assembly by an output plate assembly 249 similar to a disk which is abutted to the driving end of the cylinder block around its periphery by means of bolts 251, the conditioning end being the " lower end ", the output plate assembly and cylinder block together defining a chamber 252, the eight cylinders opening at their non-operating ends or" lower "to the chamber. It will be appreciated that the supporting shaft of the driving track and the output shaft cooperate by means of the bearing 223 to form a central support shaft for the rotor assembly, the supporting shaft of the driving track being more or less fixed and rotating the output shaft with the rotor assembly. Each piston is connected at its lower end to a roller 254 that is in continuous rolling contact with the driving track 225, thereby reciprocating the pistons 231 to 238, due to the cyclic combustion of fuel in the cylinders and the actuation The combination of the rollers with the driving track will cause the rotor assembly to rotate as they will be well understood based on said PCT request. The torque is transferred from the pistons and the piston ring assemblies to the cylinder block and the output shaft by means of a number of linear bearings 256 which slide in linear guide pins 257 spaced around the connecting rings of the piston rings. pistons. It will be noted that the ring assemblies 241 and 242 of the pistons, the rollers 254, the driving track 225, the linear bearings and the linear guide pins and the lower parts of the pistons are all housed inside the chamber 252, so that the oil can be contained therein to initialize all the moving parts that require oil lubrication. The embodiments illustrated in Figures 5 and 6 are similar to those in Figures 1, 2 and 3, and accordingly, the corresponding components are numbered with the same numbers, but starting with a 3 or a 4 instead of a 2. Both of these embodiments incorporate different elements to those of Figures 1, 2 and 3 for torque transfer from the pistons to the output shaft. In Figure 5 it can be seen that the piston connecting ring assemblies 341 and 342 (not shown) have radially arranged grooved portions 356 which are slidably mounted in guide channels 357 provided in the cylinder block parallel to the cylinder block. Longitudinal geometric axis 317. The torque transfer element shown in Figure 6 is considered to be particularly effective and includes a plurality of captured ammunition assemblies 455, each of which comprises ammunition 456 and two halves 457a and 457b of ball track disposed around the periphery of each piston ring assembly, typically having one set per piston. Each track half has a cylindrical track formed therein of a fractionally larger diameter than the ammunition, so that the two halves together form a closed cylindrical track adapted to contain the ammunition therein, allowing the ammunition to roll to along the track. The half track 457a is fixed to the piston ring assembly and the other half track 457b is fixed to the cylinder block for rolling movement of the ammunition within the track halves parallel to the longitudinal axis. It will be understood that each half track 457a has reciprocating movement with its respective connector ring assembly, thereby being displaced longitudinally in relation to its associated half track 457b, effectively transferring the ammunition torque from one half track to the other half track. As illustrated in Figure 5 (and similarly in the Figure 6), coolant is supplied to the rotor assembly for passage through a water jacket 371 inside the cylinder block by means of a central hole 370 provided in the support shaft 319 of the driving track and openings 372 provided therein. , then emerging from the upper end of the cylinder block 327 adjacent to the support shaft of the driving track through an outlet passage conduit. 373 that is sealed against an annular outlet passage duct 374 provided on the inner face of the induction end plate. The coolant exits the induction end by means of an opening (not shown) to cool in a radiator in a normal manner. Seals 376 and 377 and 379 are provided in recesses in the central hole 346 of the cylinder block on opposite sides of the bearing 347 and similarly a seal 378 is provided on the "upper" side of the bearing 323 to contain coolant in the water jacket . The lubricant is supplied to the lower end components by means of a supply conduit 381 which passes through the central hole 370 and which opens into the chamber 352. In the engine various oil pathways and supply lines are provided as needed , for example, the oil path 382 for effective lubrication, as will be understood by those skilled in the art. The induction / exhaust end plate 213 provides a mounting for external items, such as spark plugs, fuel injectors, exits and exhaust lines, accessories for cooling supply, accessories for electronic ignition, and similar items, as will be understood in basis to said PCT application. The motors described in the present specification operate in a manner similar to that described in said PCT application, the main difference remaining in that the driving track element is supported by a central axis, which results in advantages as mentioned above. The invention described in the present specification may have other variants and modifications, as will be readily apparent to those skilled in the art without departing from the scope and scope of the invention, as defined in the appended claims.

Claims (22)

1. A rotary internal combustion engine of the type having a rotor assembly supported in a housing for rotation about a longitudinal axis, said housing having two end plates spaced apart from each other, and said axis being the axis of rotation of an axis of rotation. outlet operatively connected to one end of said rotor assembly, the other end being free and passing through an opening in one of said end plates, said rotor assembly including a plurality of pistons mounted for reciprocating movement in respective cylinders disposed in spaced relation about of said longitudinal axis and follower elements operatively connected to each piston and adapted to act together with the undulatory driving track element supported around said rotation axis and between said end plates, providing elements for carrying fuel to and for raising exhaust gases from operating ends of the cylinders, whereby the cyclic combustion of said fuel in said cylinders can impart reciprocating movement to said pistons with resultant thrust against said driving track element, so that rotation of said assembly occurs. rotor and output shaft; characterized in that said undulating driving track element includes an annular track mounted to a rod or support shaft disposed substantially centrally therein and in the direction of said longitudinal axis, said rod or support shaft being supported at one end by the other of said end plates and the geometric axis of said annular driving track element being the geometric axis of rotation of said rotor assembly.

2. A rotary internal combustion engine of the type having a rotor assembly supported in a housing for rotation about a longitudinal axis, said housing having two end plates spaced apart from each other, and said axis being the geometric axis of rotation of a output shaft operatively connected to one end of said rotor assembly, the other end being free and passing through an opening in one of said end plates, said rotor assembly including a plurality of pistons mounted for reciprocating movement in respective cylinders arranged in relation spaced around said longitudinal axis and follower elements operatively connected to each piston and adapted to act together with the undulatory driving track element supported around said rotation axis and between said end plates, providing elements for carrying fuel to, and for carrying exhaust gases from operating ends of the cylinders, whereby the cyclical combustion of said fuel in said cylinders can impart reciprocating movement to said pistons with resultant thrust against said driving track element, so that the rotation of said piston is produced. rotor assembly and output shaft; characterized in that said plurality of pistons are arranged in two or more assemblies, each assembly having two or more pistons arranged in spaced relation about said rotation axis and interconnected by means of piston connecting elements, so that the pistons of each the assembly is displaced in unison, said undulatory driving track follower element and said undulating driving track element arranged so that the direction of travel of one set of pistons is generally opposite to the direction of another set of pistons, and said The undulating driving track element includes an annular track mounted to a rod or support shaft disposed substantially centrally therein, and in the direction of said longitudinal axis, said support shaft being supported at one end by the other of said ends. extreme plates, and the geometrical axis of said annular driving track element being the geometric axis of rotation of said rotor assembly. A rotary internal combustion engine according to claim 1 or claim 2, wherein said cylinders are provided in a cylinder block, and said rod or support shaft is coaxial with said output shaft and rotatably supports said cylinders block. A rotary internal combustion engine according to claim 3, wherein said output shaft is operatively connected to said cylinder block by an output plate assembly, said cylinder block and said output plate assembly defining said plate. together a chamber around said rod or support shaft and said driving track element, said driving track follower element being housed inside said chamber. A rotary internal combustion engine according to claim 4, wherein said cylinder block is supported in a sealable manner by said support shaft or shaft, and said outlet plate assembly is sealably connected to said block of cylinders. 6. A rotary internal combustion engine according to claim 3, wherein said rod or support shaft is supported at its other end by said output shaft or said output plate assembly. A rotary internal combustion engine according to any of claims 2 to 6, wherein said piston connector element includes a ring disposed around said rod or support shaft, and said ring connecting a set of pistons movable with reciprocating movement inside the ring that connects another set of pistons. 8. A rotary internal combustion engine according to claim 7, including a torque transfer element d for transferring torque of respective ring to said output shaft. 9. A rotary internal combustion engine according to claim 8, wherein said torque transfer element includes a ammunition rotatably captured in part in a recess associated with the respective ring and partly in a recess associated with said block. d cylinders and / or said output plate assembly. A rotary internal combustion engine according to claim 8, wherein said torque transfer element d includes a linear guide shaft disposed between said cylinder block and said output plate assembly d and fixed thereto, and a linear cushion assembly slidably mounted on said linear guide shaft fixed to said ring. A rotary internal combustion engine according to any of the preceding claims, wherein said driving track element is supported by another end plate for pivotal movement about a longitudinal axis. 12. A rotary internal combustion engine according to any of the preceding claims, wherein said undulating driving track element is movable towards and away from said other end plate. 1

3. A rotary internal combustion engine according to claim 12, and including elements for moving said driving track element toward and away from said other end plate and / or pivoting said driving track element in relation to said other extreme plate. A rotary internal combustion engine according to claim 7 or claim 8, wherein said driving track follower element includes a roller mounted for rotation about a geometric axis at right angles to said longitudinal axis. A rotary internal combustion engine according to claim 14, wherein said roller is in a non-captive relationship with its driving track element, by virtue of which the or each driving track element has a single continuous undulating face , against which each roller is calzable only in the part of the periphery of each roller that is more distant from the respective piston. 16. A rotary internal combustion engine according to any of claims 3 to 15, wherein said other end plate has openings therein provided with mouth elements adapted to register with corresponding movable mouths in said cylinder block to admit fuel to the operative ends of the cylinders, said other end plate being at the end of the cylinder. induction and exhaust of the engine, and constituting a mounting for fuel injectors, spark plugs. or equivalent elements as required for the particular engine and the exhaust outlet elements. A rotary internal combustion engine according to claim 16, wherein said other end plate has a pair of diametrically opposed spark plugs constituting said ignition plug elements or equivalent elements, a pair of sets of injectors of diametrically opposed fuel constituting said fuel injector element, and a pair of diametrically opposed exhaust outlets constituting said exhaust outlet element, all said pairs being arranged at spaced intervals to act together with cylinder ports to allow successive intake functions , compression, motor expansion and piston exhaust. A rotary internal combustion engine according to any of the preceding claims, wherein said support shaft or shaft has an orifice adapted to provide a cooling input element to said rotor assembly, with inlet passage conduits being provided therefrom. said hole to said cylinder block. A rotary internal combustion engine according to any of the preceding claims, wherein said housing includes a substantially cylindrical carcass body sealingly connected to, between said two end plates spaced apart from each other. 20. A rotary internal combustion engine of the type having a rotor assembly supported in a housing for rotation about a longitudinal axis, said housing having two end plates spaced apart from each other, and said axis being the geometric axis of rotation of a output shaft operatively connected to one end of said rotor assembly, the other end being free and passing through an opening in one of said end plates, said rotor assembly including a plurality of pistons mounted for reciprocating movement in respective cylinders arranged in relation spaced around said longitudinal axis and follower elements operatively connected to each piston and adapted to act together with the undulating driving track element supported around said rotation axis and between said end plates, providing elements to carry fuel to, and torque to carry exhaust gases from operating ends of the cylinders, whereby the cyclic combustion of said fuel in said cylinders can impart reciprocating movement to said pistons with resultant thrust against said driving track element, so as to produce the rotation of said piston. rotor assembly and output shaft; characterized in that said plurality of pistons are arranged in two or more assemblies, each assembly having two or more pistons arranged in spaced relation about said rotation axis and interconnected by means of piston connecting elements, so that the pistons of each assembly they move in unison, said undulatory driving track follower element and said undulating driving track element arranged so that the direction of travel of one set of pistons is generally opposite to the direction of another set of pistons; characterized in that each of said piston connecting elements includes a ring arranged around said rod or support shaft, and said ring connecting a set of pistons is movable with reciprocating movement within a ring connecting another set of pistons. 21. A rotary internal combustion engine according to claim 1, which includes two sets of pistons disposed equidistantly of the longitudinal axis, whereby all the pistons of said two assemblies can act together with the same driving track element. 22. A rotary internal combustion engine substantially described above with reference to any of the figures of the accompanying drawings. SUMMARY A rotary internal combustion engine (200) of the type having a rotor assembly (216) supported in a housing (210) for rotation about a longitudinal axis (217), the housing having two separate end plates (212, 213) ) and the shaft which is the axis of rotation of an external arrow (218) operatively connected to one end of the rotor assembly, and the other end which is free and which passes through an opening in one of the end plates, the rotor assembly including a plurality of pistons (231 to 238) mounted for reciprocating movement in respective cylinders (228) placed in spaced apart relation about the longitudinal axis, and the cam follower means (254) operatively connected to each piston and adapted to coact with the cam drive curve means (225) held around the axis of rotation and between the end plate means (215) that are provided to transport the fuel to, and to transport the gas s of exhaust from the operating ends of the cylinders, so that the cyclic combustion of said fuel in the cylinders imparts the oscillation to the pistons with the resultant impulse against the motive cam curve means to cause the rotation of the rotor assembly ( 216) and the exit arrow (218); characterized in that the undulating cam driving curve means includes an annular drive curve mounted to a support rod or arrow (219) positioned substantially centrally therein and extending in the direction of the longitudinal axis, the support rod or arrow which is supported at one end by the other of the end plates (213) and the axis of the annular cam drive curve means which is the axis of rotation of the rotor assembly. * * * * *