AU2002302034B2 - Axial Piston Machine - Google Patents

Description

Regulation 3.2

AUSTRALIA

PATENTS ACT, 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Actual Inventor: Address for service in Australia: NOEL STEPHEN DUKE NOEL STEPHEN DUKE A J PARK, Level 11, 60 ACT 2601 Axial Piston Machine Marcus Clarke Street, Canberra Invention Title: The following statement is a full description of this invention, including the best method of performing it known to me/us -2- "IMPROVEMENTS IN OR RELATING TO AXIAL PISTON MACHINES TECHNICAL FIELD This invention relates to axial piston machines and other mechanism of similar nature, and in particular to such mechanism having a crank shaft.

BACKGROUND ART Various engines/pumps utilizing a crank shaft are currently known. Such engine/pumps are more commonly known as wobble engines/pumps or swash plate engines/pumps. Wobble engines/pumps have axial pistons disposed from a wobble plate which is fixed on an output/input shaft at an acute angle. In the case of an engine, power received from the pistons is transferred to the wobble plate during the power stroke, displacing the wobble plate axially, and as a result rotating the shaft. The operation of a wobble pump is in reverse order, wherein power is applied to the input shaft to displace fluid inside the cylinders.

Modem developments in wobble engines/pumps have included changes in the configuration and operation of the pistons/cylinders and in inlet/outlet porting of the fluids. The drive mechanisms of such modem machines are nevertheless very complex, requiring many parts which are both difficult to assemble and also difficult to maintain such engines/pumps also have a lot of components operating under high frictional forces.

Previously published New Zealand Patent No.221366 discloses therein a means to transfer the wobbling motion of a disc to a rotary motion of the shaft and visa versa.

Further disclosed therein is a suitable means of providing power to or from the disc by way of internal cylinder engine or hydraulic/pneumatic motors. There is however no detail on any means by which the cylinder engine is or can be coupled to either the disc or the shaft, such that the invention can operate as a compact simple unit.

New Zealand Patent No. 150235 describes a continuous disc acting as pistons inside a chamber. The disc is non planar and rotation thereof inside the chamber forms pockets which are compressed and expanded at differing angles of rotation.

-3- The complex nature of the disc, output and crank shafts, chamber and other dependent mechanisms make such an engine/pump expensive and difficult to make.

New Zealand Patent No.131852 describes a two stroke or four stroke engine also operable as pump, in which pistons of circular cross-section which are bent in an arc are located inside curved cylinders disposed axially about a central axis. Power from the rotating cylinders is transferred to the output engine block, the spider in this invention remaining stationary.

Most modem wobble type engines/pumps require many complicated parts to ensure efficient operation. Difficulties exist in the sealing of cylinders to ensure that no fluid escapes undesirably, and in the assembly and maintenance. Such engines also have problems operating in balance.

It is an object of the present invention to provide an engine which will at least provide the public with a useful choice.

DISCLOSURE OF THE INVENTION Accordingly the present invention may broadly be said to consist in an axial piston machine having port means providing a series of intake and exhaust ports fixed relative to said port means, each connected respectively to an air intake or air and fuel mixture source and (ii) an exhaust system, fuel injection means from said housing, an fuel ignition means, a shaft rotatable relative to said port means, said shaft carrying a crank shaft having a crank axis oblique to the shaft axis, at least one cylinder defining a combustion chamber, said cylinder carried by a combustion chamber housing rotatable about the shaft axis, said combustion chamber housing being indexed at some lesser rate of rotation to the speed of rotation of said shaft and wherein each cylinder includes at least one port open to said combustion chamber, capable during operation of being brought into and out of an operative -4communication with each of said series of intake and exhaust ports, and, wherein each cylinder has an inlet to said combustion chamber from said fuel injection means, a piston for reciprocal motion in each said combustion chamber, a piston control means provided to said crank shaft and controlling the piston moving motion within each combustion chamber as the shaft rotates relative to said combustion chamber and each of said shaft and said chamber housing rotates relative to said port means, wherein said operative communication of said at least one port of each cylinder with each of said series of intake and exhaust ports occurs during a stroke of each piston in said combustion chamber for the axial piston machine, and wherein each said cylinder is removably secured to said combustion chamber housing.

Preferably said combustion chamber housing carries at least three cylinders, said combustion chamber housing rotating as an assembly about the shaft axis, each of said pistons of each of said combustion chambers being reciprocable moveable within each of said combustion chambers and also rotatable therewith about said shaft axis.

Preferably each said combustion chamber is defined by said cylinder and in which each said piston is movable between the limits of (TDC) and (BDC) defined by the angle between the crank axis and shaft axis.

Preferably a connection member is provided between each of said pistons and said piston control means to control the reciprocal movement of each respective piston between (TDC) and (BDC) within its cylinder.

Preferably said port means presents a series of intake and exhaust ports at such intervals and sequences on a pitch circle diameter of a planar surface of said port means such that said at least one port of each of said cylinders, is in operative communication over a predetermined range of rotation, with said intake and exhaust ports as said combustion chamber housing rotates relative to said port means.

Preferably said at least one port of each said cylinders sealably rotates over said substantially planar surface and at intervals provides gas communication with said intake port(s) during the induction stroke of said piston (of a 4 stroke cycle) for air or air and fuel mixture intake into said combustion chamber, and (ii) said exhaust port(s) during the exhaust stroke of said piston (of a 4 stroke cycle) for displacement of exhaust gas from said combustion chamber, wherein sealable engagement of said at least one port of each said cylinder is provided between said intake and exhaust ports for said compression and power strokes of a four stroke cycle.

Preferably for each said cylinder there are two ports sealably rotatable over said substantially planar surface during compression and power strokes and at intervals provides gas communication with said intake port and said exhaust port during the induction/scavenging stroke of a 2 stroke cycle for air or air and fuel mixture intake and exhaust displacement from said combustion chamber.

Preferably each connection member extends from a point on the perimeter of said piston control means to it associated piston, each of said connection rods having degrees of freedom with respect to said piston control means to allow for the linear movement of each said piston within each said combustion chamber between its top dead centre (TDC) and bottom dead centre (BDC).

Preferably two degrees of freedom for one piston are provided at the engagement of the associated said connection member with said piston control means, a first degree of freedom being to provide radial translation of said connection member from said crank axis and a second degree of freedom to provide relative rotation between said piston control means and the associated said connection member and three degrees of freedom are provided for the remaining piston, said first and said second degree and a third degree in a direction tangentially to the rotational plane defined by said piston control means.

Preferably said combustion chamber housing is indexed by an indexing means to said output shaft such that rotation of said output shaft is proportional (but in the opposite direction) to the rotation of said combustion chamber housing (or vice versa) about said shaft axis.

-6- Preferably two combustion chamber housings are provided, each to present pairs of substantially opposed pistons within respective said cylinders and each of two said cylinders being rotatable about the shaft axis and each of two said cylinders located adjacent a corresponding said port means providing said series of intake and exhaust ports (an optional fuel injection means and/or air/fuel ignition means), a connection member for each pair of opposed pistons, and engaged intermediate of its distal ends with said piston control means.

BRIEF DESCRIPTION OF THE DRAWINGS: Figure 1 is a sectional view through a preferred form of a six cylinder spark ignition engine of the present invention; Figure 2 is a partially cross-sectioned, partially schematic representation of part of the engine illustrated in Figure 1 detailing some of the essential geometry; Figure 3 is a perspective view of some of the components of the internal assembly of the engine of Figure 1, including the two cylinder head providing means, piston control means, shaft and associated gearing; Figure 4 is a perspective view of some of the components of the internal assembly of the engine of Figure 1, including the two cylinder head providing means, piston control means, and shaft; Figure 5 illustrates the path traced by the crank axis from point X as shown in Figure 2; Figure 6 illustrates the path traced by the crank axis through point X as shown in Figure 2; Figure 7 illustrates the rotations and translations of the piston control means, crank axis, connection means and pistons in operation of the preferred form of the engine of the present invention shown in Figure 1; -7- Figure 8 is a plan view of the cylinder head providing means, and associated cylinders of the engine of the preferred form of the invention shown in Figure 1; Figure 9 is a sectional view through section AA of Figure 8; Figure 10 is a perspective view of one of the cylinder head providing means of Figure 1, which also carries the associated annular gear; Figure 11 is a partial perspective view illustrating in more detail a port of the cylinder head providing means and associated cylinder; Figure 12 and 13 are perspective views of a crank shaft, shaft and balancing masses of Figure 1; Figure 14 is a perspective view of the piston control means of the engine of the preferred form of the invention shown in Figure 1; Figure 15 is a perspective view of the piston control means as mounted on the crank shaft; Figure 16 is an end view of a connection means of an engine of the preferred form of the invention shown in Figure 1, the connection means illustrated having two translational and one rotational degree of freedom; Figure 17 is a sectional view of part of the connection means of Figure 16; Figure 18 is a top view of the connection means pin for the attachment of the connection means to the piston control means; Figure 19 is a side view of the connection means pin of Figure 18; Figure 20 is a cross-sectional view of the connection means bush shown in Figure 17, Figure 21 is a perspective view of the engine of the preferred form of the invention shown in Figure 1, wherein the ported means and end member at one end has been removed, Figure 22 is a perspective view of part of the engine of the preferred form of the invention shown in Figure 1; Figure 23 is a perspective view of the planet gears and associated support rings of the engine of the preferred form of the invention shown in Figure 1; -8- Figure 24 is a perspective view illustrating the engagement of the planet gears with the annular gear of the engine of the preferred form of the invention shown in Figure 1; Figure 25 is a plan view illustrating in part the gear teeth of the annular gear, planet gears and shaft gear; Figure 26 is a sectional view through section AA of Figure Figure 27 is a perspective view of an end member of the engine of the preferred form of the invention of Figure 1; Figure 28 is an alternative perspective view of the end member and ported means of Figure 27; Figure 29 is a plan view of the end member of Figure 27; Figure 30 is a sectional view through section AA of Figure 29; Figure 31 is a plan view of the end member of Figure 29 with which the ported means is engaged and on which the preferred configuration of port means cooling is illustrated; Figure 32 is a sectional view through section AA of Figure 31; Figure 33 is a partial bottom view of the ported means and end member of Figure 28; Figure 34 is a perspective view of the engine of the preferred form of the invention shown in Figure 1 in which additionally parts such as carburetors, air filters, exhausts, starter motor, coils and throttle controls are illustrated; Figure 35 illustrates a sequence of positions of cylinders relative to the ported means of the engine of the preferred form of the invention shown in Figure 1 wherein the crank is counter-rotating to the cylinders; Figure 35A illustrates a sequence of positions of cylinders relative to the ported means of the engine of the preferred form of the invention shown in Figure 1 wherein the crank is co-rotating to the cylinders Figure 36 illustrates a sequence of positions of cylinders relative to the ported means, in the operation of a cylinder/porting configuration of a similar engine shown in -9- Figure 1, having 5 pairs of opposing cylinders wherein the crank is co-rotating with the cylinders; figure 36A illustrates a sequence of positions of cylinders relative to the ported means, in the operation of a cylinder/porting configuration of a similar engine shown in Figure 1, having 5 pairs of opposing cylinders wherein the crank is counter-rotating with the cylinders; Figure 37 illustrates a sequence of positions of cylinders relative to the ported means of an alternative form of the engine of Figure 1, wherein there are 7 pairs of opposing cylinders and wherein the crank is co-rotating with the cylinders; Figure 37A illustrates a sequence of positions of cylinders relative to the ported meang of an alternative form of the engine of Figure 1, wherein there are 7 pairs of opposing cylinders and wherein the crank is counter-rotating with the cylinders Figure 38 illustrates an alternative arrangement of engine of the present invention, wherein there is no relative rotation between the cylinder head providing means and ported means; Figure 39 illustrates yet another arrangement of engine of the preferred form of the invention shown in Figure 1, wherein a discontinuous shaft is utilised; Figure 40 illustrates a cross-sectional view through yet an alternative form of the present invention utilising a partial spherical like cylinder arrangement; Figure 41 is a partially sectioned perspective view of an engine of form of the present invention shown in Figure Figure 42 illustrates a plan view of the pistons of the engine of Figure 41 and Figure 43 illustrates a sequence of positions of cylinder chambers relative to the ports during the operation of a six or three cylinder engine of an engine of the present invention shown in Figure 41.

Figure 44 is a sectional view through another preferred form of the engine of the present invention of Figure 1 adapted to run in a two stroke cycle, Figure 45 is a sectional view of an alternative arrangement of the engine of Figure 44, Figure 46 is a sectional view through the engine of Figure 1 illustrating lubrication and cooling fluid flows.

Figure 47 is a more detailed view of that part of figure 1 about the cylinder head providing means; Figure 48 is a plan view of an end member showing the relative angles between ports and spark plugs; Figure 49 is a more detailed view of that part of figure 1 about the annular gear.

DETAILED DESCRIPTION OF THE INVENTION: The most preferred form of the present invention which is herein described in detail is a combustion engine having three pairs of opposing pistons. The engine is shown in cross section in Figure 1, and various details of its components and operation described are illustrated in Figures 2-33. In the most preferred form of the invention, the engine as shown in Figure 1, consists of a shaft 1 which extends substantially all the way through the engine which carries a crank shaft 2, having a crank axis 2 A oblique to the shaft axis 1 A. The angle between the shaft axis 1 A and the crank axis 2 A will herein be described and referred to as the crank angle. Although herein described is a shaft which is a separate member to the crank shaft, the entire crank shaft/shaft arrangement may be of one part (ie the crank shaft).

The rotation of the shaft 1 about its shaft axis 1 A will rotate the crank shaft 2 about the shaft axis 1 A. Figure 6 illustrates the path traced by the crank axis 2 A about the shaft axis 1 A. At point X, where the crank axis 2 A and shaft axis 1 A intersect, there is no relative motion of the crank axis 2 A to the shaft axis 1A Carried by the crank shaft 2 and able to rotate about the crank axis 2 A is a piston control means 3. Most preferably the piston control means 3 is rotatably mounted from the crank shaft 2 by tapered roller bearings 50. Preferably such bearings are located at each end of the crank shaft so as to axially locate the piston control means 3 to the crank shaft 2. The bearings further ensure that the piston control means plane of rotation 3A remains at substantially 900 relative to the crank axis 2 A Although 11 undesirable, it is possible for this invention to be performed when the piston control means plane of rotation 3 A and the crank axis 2 A are not at 900 to each other.

The piston control means 3 controls the reciprocal motion of three pairs of opposed pistons 6. It has been envisaged that any number of pairs of opposed pistons can be utilised in an engine of this invention, and brief details of such are discussed hereafter. Pistons 6 are located at the distal ends of connection means 4 which are disposed from and at the perimeter of the piston control means 3. In the preferred form of the present invention, three connection means 4 are disposed from and at the perimeter of the piston control means at 1200 intervals. Each connection means 4 is located and is of shape to be symmetrical about the piston control means plane of rotation 3 A however this need not be essential, and an asymmetric connection means 4 with changes to the associated geometry, may be used in this engine.

The pistons may be of any cross section with respect to its reciprocal axis, however in the preferred form of the present invention, the pistons have been illustrated as having a circular cross section.

Each piston is able to reciprocate inside of a complementary cylinder 12.

The cylinders 12 are mounted in cylinder head providing means 5 which holds the cylinders 12 in a complementary array to the pistons. The cylinders may be made of one unitary member as part of the cylinder head providing means 5 by, for example, casting and machining, or as in the preferred form of individual parts.

In a most preferred form the engine has two cylinder head providing means, one for each set of opposed pistons.

Each cylinder head providing means 5 and cylinders 12 are able to rotate about the shaft axis 1A and are equispaced from point X as shown in Figure 1. The use of cylinder head providing means bearings 52 between the cylinder head providing means and shaft 1, provides a suitable means of allowing such rotation. Preferably such bearings are ball bearings, however other suitable forms of bearing may be used.

The rotation of each of the two cylinder head providing means 5 about the shaft axis 1A is synchronous. Such synchronous rotation is in the preferred form achieved by the use of cylinder head providing means connectors 53. Such cylinder head providing -12means connectors 53 are secured at their distal ends to each of the cylinder head providing means 5 by a suitable fastening means such as a bolt or machine screw. In the preferred form there are three cylinder head providing means connectors 53, however a person skilled in the art will realise that any number of such connectors 53 or other configurations thereof, will ensure synchronous rotation of the two cylinder head providing means Located adjacent each cylinder head providing means 5 are ported means 13, which in the preferred form of the invention shown in Figure 1, also carry spark plugs 57 for the ignition of fuel in the cylinders 12 at appropriate times.

The ported means 13 are each located by end members 54. Each end member 54 locates the shaft 1 by the use of end member bearings 55 having an axis of rotation coaxial with the shaft 1. The bearings allow rotation of the shaft 1 to the end members 54. Preferably the bearings 55 are tapered roller bearing, which are able to bear against both radial and axial forces.

Each of the ported means provide porting for the inlet of fuel into each cylinder and outlet of combusted gases out of each cylinder. The location of the ports in the ported means 13 and end members 54 allow the in-flow of fuel during the induction stroke of each piston, and outlet of exhaust gases during the exhaust stroke of each of the pistons of a four-stroke engine. Additionally the ported means locate at appropriate intervals spark plugs for the ignition of the fuel when the piston is at or near top dead centre. The rotation of the cylinder head providing means relative to the ported means about the shaft axis 1 A allows for the ports and spark plugs 57 to be presented to each cylinder in the appropriate sequence.

A rotational relationship between the cylinder head providing means 5 and the shaft 1 is achieved by the use of gears. In the preferred form one of the cylinder head providing means carries an annular gear 19. This gear 19 engages with planet gears which are associated with their adjacent end member 54. They are rotatable about their axes to index the rotation of the cylinder head providing means 5 and the shaft gearing 11.

-13 The expansion force produced by the combustion of fuel in a cylinder 12 is transferred from the pistons 6 through the connection means 4 to the piston control means 3. This moment about point X provides a moment to the crank shaft 2. Such a moment applied to the crank shaft 2 causes a rotational displacement thereof about the shaft axis 1 A and causes the shaft to rotate correspondingly.

Each of the ported means 13 have therein ports for the inlet and outlet of fuel to and from the cylinders 12. Such ports are arranged on a pitch circle diameter from the shaft axis 1 A and align with the openings to each cylinder over a specific range of angular rotations of the cylinder head providing means 5. As the shaft 1 rotates as a result of the force on the crank shaft 2, the rotating motion is transferred via the planet gears 10 to the cylinder head providing means 5. When the shaft 1 rotates the cylinder head providing means 5 orbits about the shaft axis 1 A. The orbiting of the cylinder head providing means 5 about the shaft axis 1A causes the openings to each cylinder to 1) align with the inlet/outlet ports during certain ranges of orbital positions of each cylinder and 2) to be closed during other ranges of rotation. The rotational positions of the cylinder head providing means relative to the ported means for a four stroke engine are such that; fuel mixture is able to be induced (or blown) into the cylinder 12 through inlet ports during the downward or expansion stroke of the piston 6, fuel mixture is able to be compressed during the upward or compression stroke of the piston 6 (and also injected for diesel operated engines), combusting fuel mixture is able to be ignited and expand inside the cylinder 12 forcing the piston 6 downward during the power stroke, exhaust fluids are able to be expelled from the cylinder 12 through exhaust ports 8 during the upward or exhaust stroke of the piston 6, In the preferred form of engine as shown in Figure 1 the planet gears 10 induces a rotation in the cylinder head providing means 5 in an opposite direction to the rotation of the shaft 1.

However, with an alternative arrangement of the planet gears and annular gear, wherein the annular gear is carried by the ported means 13 and the planet gears are 1. 1 -14carried by the cylinder head providing means 5, co-rotation of the shaft 1 and the cylinders/cylinder head providing means and pistons will be achievedL Illustrated in Figure 35 is a sequence showing the alignments of the cylinder openings 12' in the cylinder head providing means 5' relative to the inlet/outlet ports, of the ported means 13'. It illustrates the engine of figure 1 wherein the crank shaft is counter rotating to the cylinders,' at a rotation of 3:1, proving 4 power strokes per revolution of the crank shaft..

The arrow C indicated in Figure 35 is the direction of rotation of the crank, and the arrow TDC is the top dead centre position of the crank.

In following around cylinder opening 12', it can be seen that at top dead centre the cylinder 12' is exposed partially to both inlet port 15' and exhaust port 8' in the ported means 13'. At top dead centre the exhaust fluids have all substantially been expelled from the cylinder 12'. Immediately after the piston 6' reaching top dead centre fuel mixture is induced (or blown) into the cylinder 12' through inlet port 15'. As the piston travels downwardly from the top dead centre position the cylinder 12' become fully aligned with the inlet port 15' (intake 900).

At substantially bottom dead centre, the cylinder 12' becomes fully sealed by the ported means and as the piston 6' travels through bottom dead centre the fuel inside the cylinder 12' starts to compress.

As the piston 6' travels towards top dead centre, the fuel mixture is ignited. For engines utilising petrol as a fuel, such ignition is initiated by the sparking of a spark plug. However fuels such as diesel will ignite due to their compression, and therefore no ignition initiating means is required. This alternative mode of operation is hereafter described in more detail.

As the piston 6' travels from top dead centre to bottom dead centre as a result of the combustion of the fuel mixture, power is transferred to the shaft via the connection means 3 and crank shaft 2. As the piston 6' reaches bottom dead centre, the cylinder chamber 12' becomes aligned with a second exhaust port 8' located in the ported means 13. As the piston passes through bottom dead centre, and returns to top dead centre, exhaust fluids are able to be expelled out through outlet port Thereafter the sequence repeats for the next compression, power, exhaust, and induction strokes. The positioning of the inlet and outlet ports and spark plugs on the ported means, and the indexing of the head providing means to the shaft 1 and ported means 13 results in the openings to the cylinders 12 to be aligned with the appropriate ports and spark plugs at the appropriate axial positions of each of the pistons relative to the cylinders. As the engine of the preferred form of the invention is double acting, the ports and spark plugs of the two ported means are not aligned with one another ie when one of a pair of pistons is travelling in its power stroke, the other of the pair of pistons will most preferably be in its exhaust stroke. Alternatively, whilst one of the pair of pistons is going through its power stroke, the other of the pair of pistons may be in its compression stroke. Table 1 below illustrates the alternatives to the strokes through which a pair of pistons of a four stroke engine may be travelling.

TABLE 1 STROKE OF FIRST STROKE OF SECOND ALTERNATIVE CYLINDER OF PAIR CYLINDER OF PAIR STROKE OF SECOND CYLINDER OF PAIR POWER EXHAUST COMPRESSION EXHAUST INTAKE POWER INTAKE COMPRESSION EXHAUST COMPRESSION POWER INTAKE Figure 35A is an engine of figure 1 wherein the crank and the cylinders are corotating. As a result, the crank to cylinder gearing ratio of 9:1 and the 4 inlet and 4 outlet ports per end member, 2.7 power strokes per revolution of the crank result.

-16- Figure 2 illustrates part of the engine of Figure 1, and shows the oblique angle (crank angle) between the crank shaft axis 2 A and shaft axis 1 A. The plane of rotation of the piston control means 3 is defined by the plane 3 A which is normal to the crank shaft axis 2 A The rotation of the crank shaft 2 about the shaft axis 1 A causes the distal ends of the piston control means 3 to follow a locus of an arc of centroid at point X. The crank radius 58 is the radius of the gudgeon pins connecting the connection means 4 to the pistons 6, when at top dead centre and bottom dead centre, from point X. As the reciprocation of the pistons inside of the cylinders is along a linear axis (the piston axis 6 A) there exists a slight degree of difference in the path followed by each piston between top dead-centre and bottom dead-centre and the crank radius 58. This difference is compensated for by allowing the connection means to move radially relative to the piston control means along the piston control means plane of rotation 3

A

The path difference is minimised by ensuring that the normal to the piston axis at midway between top dead-centre and bottom dead-centre of each piston, passes through the intersection of the crank shaft axis 2 A and shaft axis 1A at point X shown in Figure 2.

Figures 3 and 4 are perspective views of the internal components of the engine of Figure 1, where the cylinders 12 have not been represented. Annular gear 19 is secured to one of the cylinder head providing means 5 by use of a suitable fastening means such as bolts or machine screws. It is located at only one of the cylinder head providing means 5. In the most preferred form the annular gear 19 has square-cut teeth, however it is envisaged that helical, or double helical gears will also be suitable. The annular gear 19 is positioned on the cylinder head providing means 5 such that its centre coincides with the shaft axis 1

A.

Figure 24 is a perspective view of the annular gear 19 associated with complementary cut planet gears 10. The planet gears are held in a fixed relationship to each other by the use of a ring 59 and planet gear mounting plate 86 which hold the axis of rotation of each of the planet gears in a fixed relationship.

Figure 25 is a plan view of the annular gear 19, planet gears 10, ring 59 and shaft gear 11. Although in the preferred form of the present invention, three planet I k -17gears 10 are used, a person skilled in the art will realise that any number of such planet gears disposed between the annular gear 19 and shaft gear 11 can be used. The axes of the planet gears are held stationary relative to the ported means 13 and end member 54.

This is achieved by the fixing of the mounting plate 86 to the end member 54 by several fastening means such as screws, bolts or machine screws. When the planet gears 10 are held stationary, a clock-wise rotation of the annular gear 19 will result in an anti-clockwise rotation of the shaft gearing 11. It is envisaged that although in the present form of the invention with its preferred gearing arrangement, the end members are held stationary, alternative forms of the present invention may have a stationary shaft 1 or stationary cylinder head providing means 5. In such configurations relative rotation of the shaft 1, end members and ported means, and cylinder head providing means are as shown in Table 2 below.

TABLE 2 Clockwise shaft axis rotation cylinder head rotation ported means Output from rotation shaft axis clockwise anticlockwise fixed clockwise fixed clockwise cylinder head anticlockwise clockwise fixed fixed clockwise clockwise ported means fixed clockwise clockwise clockwise fixed clockwise When the cylinder head providing means 5 and the shaft 1 are co-rotating, by the appropriate arrangement of the annular gear and planet gears, the relative rotations of the shaft 1, end members and ported means, and cylinder head providing means are shown as in Table 3 below.

-18- TABLE3 Clockwise shaft axis rotation cylinder head rotation ported means Output from rotation shaft axis clockwise clockwise fixed clockwise fixed anticlockwise cylinder head clockwise clockwise fixed fixed clockwise clockwise ported means fixed clockwise clockwise anticlockwise fixed clockwise Figure 49 is an enlarged view of the region of figure 1 about the annular gear and bearings.

Figure 26 is a sectional view through AA of Figure 25. Most preferably the shaft gear 11 has a sleeve type arrangement to allow it to fit over the shaft 1. To ensure that the shaft gear is rotatably secured to the shaft 1, a pin, spline or key way type engagement is preferable. A person skilled in the art will however realise that many other methods of securing and/or presenting a shaft gear from the shaft are available.

For instance the gear may be cut as part of the shaft or shrink fitted thereto, but as it is preferably for the gear to be hardened it is a separate gear.

Figures 12 and 13 are perspective views of the shaft 1 and shaft gear 11, crank shaft 2 and balancing masses 60. The shaft 1 is most preferably made from medium tensile steel and is of a stepped diameter, the largest of which is in the middle, to allow the crank shaft 2, balancing masses 60, shaft gearing 11 and shaft bearings to be slidably located on the shaft 1.

-19- The crank shaft 2 is of circular cross section having a bore oblique to the crank axis 2 A The bore corresponds to that part of the shaft 1 at which the crank shaft 2 is to be located. The centre line of the bore intersects the crank shaft axis 2 A most preferably at the centroid of the crank shaft.

The crank shaft 2 is secured to the shaft 1 by the use of dowel pin. Alternatively the crank shaft may be secured to the shaft 1 by the use of splines, key ways or shrink fitting, or all such methods. Alternatively the crank shaft may be formed by machining the shaft 1. Balancing masses 60 are secured to the shaft 1 to ensure that during the operation of the engine, the out of balance forces of the rotating and reciprocating mass of parts are minimal. The balancing masses 60 are most preferably made of medium tensile steel and are secured to the shaft 1 by the use of dowel pins. Again alternative forms, as before described, of securing such masses may be used.

Because the motion of the reciprocating parts is sinusoidal, ie simple harmonic motion, only primary out of balance forces are generated. This implies that the two balancing masses can theoretically balance such out of balance masses, leaving no residual out of balance force. A simple calculation of the out of balance forces on the shaft 1 during the operation of the engine would determine the location, shape and size of the balancing masses 60 which are suitable.

Alternatively the crank shaft and shaft may be forged from a one piece billet of suitable grade of steel.

Mounted from the crank shaft 2 is the piston control means 3. The piston control means 3 is rotatable about the crank axis 2 A by the use of bearings 50. As illustrated in Figure 1, the bearings 50 are tapered roller bearings. Alternatively, ball bearings may be utilised, but due to the moments which are created by the reciprocating motion of the pistons, it is desirable that the bearings are able to bear a thrust component of force. Two tapered roller bearings 50 are secured to the ends of the crank shaft 2, as shown in Figure 1. The piston control means 3 includes a piston control means collar 61 or ring as shown in Figure 14 having an inside bore, able to engage with the outer race of the tapered roller bearings 50. This ensures that the piston control means is axially restrained from moving relative to the crank shaft.

Annular thrust plates 73 locate onto the crank shaft by use of machine screws to locate the bearings axially thereto.

Radially extending from the piston control means collar 61 are piston control means arms 62. The number of arms 62 of the piston control means correspond to the number of pairs of pistons 6 used in the engine.

The piston control means may be of any shape and does not necessarily need to present arms as shown in Figure 14. Alternatively the piston control means may be a disc to which at its circumference, connection means are able to be located.

Connected to the distal ends of the arms 62 of the piston control means 3 are connections means. Figure 16 illustrates the end view of a connection means 4. In the most preferred form one connection means 4 is located at the distal ends of each of the arms 62, andeach control a pair of opposing pistons. It is however envisaged that this engine may operate in a single acting mode, wherein each connection means would control only one piston. However, in the most preferred form the engine is double acting, as in this mode of operation the out of balance forces and moments are more easily balanced. Furthermore the construction of the embodiment of the engine is not much less complex for a single acting cylinder arrangement compared to a double acting cylinder arrangement of twice the capacity.

Each piston is connected to a distal end of a connection means 4 by the use of a standard gudgeon pin type arrangement, which extends through the gudgeon pin hole 84 in the connection means.

The connections means 4 is connected to the piston control means 3 by a connection means pin 63. The pin 63 is preferably press fitted into a hole in the piston control means, but may alternatively be a part thereof. The connection means pin 63 is located in a bush 64 which locates inside a bore of the connection means 4, as shown in Figure 17. Due to the alignment of the cylinder axis with the shaft axis, the shaft axis 1 A coincides with the plane of symmetry 4 A of the connection means 4 shown in Figure 16.

As a result of the rotation of the pistons about both the crank shaft axis 2 A and shaft axis 1 A, the connection means 4 carrying the pistons needs to be rotatable relative -21to the piston control means 3 about the piston control means plane of rotation 3

A

The connection means bush 64 shown in Figures 17 and 20 provides for this rotational degree of freedom of the connection means 4 about the piston control means plane of rotation 3

A

Many alternative means of achieving such relative rotation between the connection means 4 and piston control means 3 have been envisaged. Such include the use of roller or ball bearings, located at the piston control means or located anywhere along the piston control means arms 62. Alternatively a hinging type arrangement may be utilised as part of the connection means 4, having a pivoting axis to allow relative movement to the connection means 4.

As the displacement of the pistons inside of and relative to the cylinders is linear, but the rotation of the crank shaft 2 A about the shaft 1 A causes the locus (relative to the cylinder) of the piston control means to be an arc having a centroid at point X (shown in Figure a second degree of freedom of the connection means 4 relative to the piston control means 3 is essential. This second degree of freedom is also provided for by the connection means bush 4. The bush is able to slide backwards and forwards inside of the bore of the connections means 4, along the piston control means plane of rotation 3

A

The degree of difference in the path of each piston inside the cylinder and the locus of the piston control means has been minimised by positioning the gudgeon pin at a distance from the piston control means plane of rotation 3 A such that at midway on the line between top dead centre and bottom dead centre of the gudgeon pin, the normal thereto intersects at point X (the intersection of the crank shaft axis 2 A and shaft axis 1 A) as shown in Figure 2. In the most preferred form the connection means 4 are symmetrical about the piston control means plane of rotation 3 A and to this extent the essential geometry of the cylinder head providing means and cylinders are substantially symmetrical about the axis normal to the shaft axis 1

A.

The rotation of the pistons about the crank shaft axis 2 A and its rotation about the shaft axis 1 A causes yet a further difference in relative displacement of the piston control means to of each respective cylinder. The difference is due to the nonsynchronous wobbling like rotation of the piston control means 3 about the crank shaft 22 axis 2 A and the cylinder head providing means 5 about the shaft axis 1 A when viewed from the direction of the shaft axis 1 A. As the pistons rotate synchronously with the cylinder head providing means 5, the non-synchronous rotation of the piston control means 3 to pistons 6 needs to be absorbed somewhere there between. In the most preferred form this difference in rotation is compensated for by the connection means bush 64. The bush provides a third degree of freedom to the connection means in a direction of the piston control means plane of rotation 3

A

However to ensure there is some positive association of the connection means with the cylinder head providing means, one of the connection means does not have this third degree of freedom relative to the piston control means 3. The piston control means arm extending to the connection means 3 having only two degrees of freedom, does rotate synchronously with the cylinder head providing means. The third degree of freedom in the other two connection means is achieved by the connection means bush 64 and connection means pin 63. Figures 18 and 19 illustrate the connection means pin 63, having therein slots or reliefs 65. The connection means bush 64 as shown in Figure 20 has ridges complementary to the connection means pin slots 65. Figure 17 shows the relationship of the connection means pin 63 and connection means bush 64 when located inside of the connection means 4. The slots 65 allow for the connection means to translate relative to the piston control means 3 in a plane parallel to the rotational plane of the cylinder head providing means The third degree of freedom may alternatively be provided in the gudgeon pins of the connection means 4, however in the most preferred form it was found to be more effective to have this third degree of freedom provided for at the connection means pins 63.

Alternatively, the piston control means arms may be pivotable at a pivot away from their distal ends, who's axis is parallel to the crank shaft axis. To ensure transmission of power from the pistons, one of such arms would be fixed and nonpivotable, and the other two would be pivotable, for a six cylinder opposed pair engine.

Most preferably the connection means 4 is made from high tensile aluminium which is either cast and machined, or machined. They may alternatively be fabricated.

23 The connection means bushes are most preferably made from sinted bronze or bronze and similarly the connection means pins 63 are of chromium steel having a high surface finish.

Figure 8 is a planar view of a cylinder head providing means 5 which carries three cylinders 12. The cylinder head providing means 5 locates and secures each of the cylinders in a fixed array. Figure 9 shows a cross sectional view through section AA of Figure 8. It shows how each cylinder 12 is secured to the cylinder head providing means 5 by a plate ring or collar which locates around the perimeter of the cylinder 12. The use of machine screws or bolts or the like, ensures secure attachment of each of the cylinders to the cylinder head providing means. Also illustrated in Figures 8 and 9 are the cylinder head providing means connectors 53 which connect each of the two cylinder head providing means 5 to each other. The connectors 53 locate into a bore or aperture of each of the cylinder head providing means 5. The cylinders are made from commonly used metal alloys for cylinders of engines known.

Each of the cylinders 12 has therein a relief to accommodate for the oscillating motion of the piston control means arms 62 relative to the cylinders.

Figures 10 and 11 illustrate the surface of the cylinder head providing means which engages with the ported means 13. A ring seal 100 shown in figures 1 and 47, having apertures located to correspond with the raised portions of the cylinder head providing means about each of the openings to the cylinders, rotates with the cylinder head providing means. The ring seal has a centroid at the shaft axis 1 A and is of internal and external diameter sufficient provide the sealing to each of cylinder openings. Preferably the ring seal is made from a hard steel such as that used for saw blades coated with a friction reducing coating.

Annular seals 101 and 102 are located about the openings to the cylinders in an annular groove and below the ring seal. Figure 47 shows in more detail, the preferred arrangement of such seals. When the compressed fluids in the cylinders attempt to escape therefrom, the increase pressure due to such fluids increase the pressure inside of the cavity 103 and press the ring seal against the ported means, closing off that -24escape route. Similarly the increase in pressure on the inside wall of seal 101 forces the seal 102 against the outside wall of the annular groove and seals off that escape route.

A person skilled in the art will realise that many other methods of sealing the cylinder openings to the ported means are possible.

In the most preferred form of the present invention, the end members 54 carry the ported means 13. Figure 28 is a perspective view of an end member 54 and ported means 13. Although in the preferred form of the present invention, the ported means 13 and end member 54 are separate parts, the ported means and end member can be a single item. In the preferred form of the present invention the end members 54 are made from aluminium, and the ported means 13 are made from a steel suitable for case hardening for durability and strength. The use of a case hardened steel for the ported means is desirable as the ported means 13 are subjected to frictional forces from their relative rotation to the cylinder head providing means 5 and also to the combustion heat from the fuel in each of the cylinders.

Each of the ported means 13 in the preferred form of the present invention, has two inlet ports 15 and two exhaust ports 8 for the induction of a fuel/air mixture and the exhaust of combusted fuel respectively.

In the most preferred mode of the present invention and wherein the engine operates in a standard four stroke counter rotating sequence, one revolution of the cylinder head providing means about the shaft axis 1 A results in each of the pistons having two four stroke cycles. As the gearing ratio is 3:1 between the shaft and the cylinder head providing means, one revolution of the cylinder head providing means relative to the ported means, results in four revolutions of the cylinder head providing means relative to the shaft, when the engine is operating in a counter rotating mode.

When the engine is operating in a co-rotating mode, wherein the cylinder head providing means rotates in the same direction as the shaft, one revolution of the cylinder head providing means relative to the ported means results in two revolutions of the cylinder head providing means relative to the shaft. The most preferred sequence of operation has been schematically illustrated in Figure 35. Spark plugs initiate the combustion of the fuel inside of the cylinders when the piston approach TDC. To this 25 extent the ported means is also provided with apertures 66 for presenting a spark plug to the cylinders at appropriate intervals. In the most preferred mode where the pistons travel through two 4 stroke cycles, two spark plugs are presented from each ported means.

The end members 54 contain apertures corresponding to those in the ported means to allow for the provision of fuel/air, and spark plugs and for the exhaust of exhaust gases to the apertures in the ported means 13.

Figure 29 is a plan view of an end member 54 illustrating the relative positions of the outlet ports 15, inlet ports 8 and spark plug apertures 66. In the preferred for of the present invention, all ports are at the same pitch circle diameter.

The apertures located on the perimeter of the end member 54 allow for the securing of structural members 68 as shown in Figures 1,21, and 22 which hold both end members 54 in fixed relationship.

Figure 30 is a sectional view through section AA of Figure 29. It shows the ported means relief 67 into which the ported means 13 is able to locate. The end member 54 of Figures 29 and 30 is that end member which houses the gearing of Figure 26 between the cylinder head providing means 5 and the shaft 1. The threaded screw holes 85 in one of the end members 54 locate the machine screws which fasten the planet gears mounting plate 86 as shown in Figure 23 to the end member 54.

Figure 32 is a sectional view through section AA of an end member shown in Figure 31. In Figure 32, the ported means 13 has been illustrated in association with the end member 54. Shown in both Figures 30 and 32 are the outlet port 8 and spark plug aperture 66 through both the ported means 13 and end member 54. The inlet and outlet ports 15 and 18, are reversed on the opposite ported means and end member located at the other end of the engine.

Although herein described are engines having openings to each cylinder at an identical pitch circle diameter, alternatively some openings may be at different pitch circle diameters, having corresponding ports in the ported means at differing corresponding pitch circle diameters. This type of arrangement can be utilised by engines having different firing sequences and geometry.

26 For the engine of the preferred form of the invention, the line drawn between the two spark plugs of one of the end members, is at 450 to the line drawn between the two spark plugs of the other end member. This 45' offset ensure that the ports, and spark plugs of each of the end members are located in the correct position for each of the opposed pairs of pistons. When the crank rotates 1800 relative to the cylinder head providing means, the cylinder head providing means is moved -450 to the ported means, and the crank is moved +1350 relative to the ported means. This total 1800 and has a ratio of 3:1 corresponding to the gearing. As a result the offset of the end members is required to be 450.

Figure 48 shows the end member of figure 29. In the preferred form of the engine of the present invention, wherein there are three pistons at each end of the engine, the angle between the spark plug centre and the most adjacent port is 67.50, and the angle between pairs of ports is 45' The inlet and outlet ports 15 and 8 respectively as shown in Figure 33 expand in cross sectional area at or towards the surface of the ported means which engages with the complementary surface of the cylinder head providing means 5. This expansion of area is desirable to ensure that a larger port area is presented to each of the cylinders as they rotate over the ports. This ensures better transfer of fluids into and out of the cylinder and also provides the required inlet and exhaust duration as the cylinders rotate past. For the size of ports used and size of cylinder openings, the intake ports opens at 300 before TDC and closes at 300 after BDC, and the exhaust port opens at 300 before BDC and closed at 300 after TDC.

Geometry for other configurations of engine can also be determined by simple calculations.

Reliefs 69 have been provided in the end members to increase their surface area to provide efficient cooling of the end members and ported means. Although herein shown, the relief 69 are of a particular configuration, any other alternative configuration to provide a suitable means of cooling can be used.

Figure 33 is a bottom view of the end member 54 and ported means 13. As shown, the ported means is most preferably ring shaped and planar. The ported means 27 may however have a bevelled surface which is presented to a complementary surface of the cylinder head providing means 5. In fact the complementary surfaces of the ported means 13 and cylinder head providing means 5 may be of any contour, however the most preferred shape is planar as this is easy to manufacture.

The bottom view of the end member 54 and ported means 13 also illustrates the planet gear screw holes 85, which are able to receive machine screws which secure the planet gear mounting plate 85 to the end member 54. Preferably there are three of such screw holes present in the end member 54. The slots 94 in the planet gear mounting plate 86 allow a degree of adjustment of the location of the planet gears relative to the end member. This degree of freedom allows for the timing of the relative rotation of the cylinder head to the ported means to be adjustable. Also included in the planet gear mounting plate 86 is a pin hole 95 which is able to receive a pin therethrough to lock the mounting plate 86 to the end member. The screws which extend through the slots 94 would not be sufficient to rotationally hold a mounting plate to the end member.

Although herein described in detail with reference to the various components and parts, is a combustion engine which has three opposing pairs of pistons, this invention can be adapted to a combustion engine with more than three opposing pairs of pistons or single acting pistons. The gear ratio between the shaft 1 and cylinder head providing means 5 is related to the number of pairs of pistons of the engine. The gear ratio of the engine of figure 1 operating in a four stroke cycle is defined by Ws Wc -N wherein Ws is the rotation of the shaft 1, Wc is the rotation of the cylinder head providing means 5 and N is the number of pairs of cylinders. Hence for three pairs of opposed pistons, the shaft rotates at three times the speed of the cylinder head providing means 5 and preferably but not essentially in opposite direction. For a corotating engine having 3 opposed pair of pistons and each end member having 4 inlet and outlet ports with a gear ratio of 9:1, Ws/Wc=+N 2 Figure 36 illustrates a sequence through half a revolution of the cylinders of a spark ignition combustion engine having five pairs of opposed pistons. In this configuration the cylinders are co-rotating with the crank. The crank to cylinder gearing -28ratio is 5:1. Each of the ported means has 2 inlet and 2 outlet ports, proving for 4 power strokes per revolution of the crank. Figure 36A show a 5 pair of opposed cylinder engine, wherein the crank is counter co-rotating to the cylinders. The gearing ratio is at and for 6 ports per ported means, results in 6 power strokes per revolution of the crank.

Similarly Figure 37 illustrates a sequence through one third a revolution of the cylinders of a spark ignition combustion engine having seven opposed pairs of pistons.

In one single revolution of the cylinder head providing means 13' of Figure 37, a single piston moves through three cycles of a four stroke cycle. Figure 37 shows the relative rotations of the cylinder head providing means 13 and the ported means through one third of a revolution, ie one four stroke cycle. Figure 37A is a counter rotating version of a seven pair of opposed cylinder engine,. The gearing ratio of the crank to cylinders is -7:1 and for 8 ports per ported means, 8 power strokes per revolution of the crank result.

In the most preferred form of the present invention as shown in Figure 1, fuel is supplied to the cylinders when required through the inlet ports 15 by natural aspiration.

The fuel and air mixture is mixed by the use of carburetters 70 located at each inlet port as shown in Figure 34. Most preferably the carburetters are 28mm ID, flat side venturi type. A person skilled in the art will realise that alternative carburetters may be used, and where the capacity of the cylinders is different to that herein described, other suitable carburetters may be required. Air is drawn into the carburetters 70 through air filters 71. A throttle controller 72 is connected to throttle cables controlling the fuel into the carburetters 70 and is thereby able to control fuel quantities drawn into each cylinder. The throttle controller, controls all four carburettors of the engine of Figure 1 simultaneously. Simultaneous operation is desirable to ensure that the expansion forces of the combusted fuel in each cylinder are substantially similar.

In the most preferred form a starter motor 73 of which part is shown in Figure 34 drives by way of belt drive at start-up, the alternator pulley 74. This in turn during start-up drives a smaller alternator pulley which connects by way of belt drive onto a pulley of shaft 1. Once the engine is operating, a suitable form of clutching or

J

29 disengaging of the starter motor from the shaft 1 is required. Such may include a sprag clutch within the starter motor. A person skilled in the art will realise that there are many alternative ways of achieving start-up. Although herein described in the most preferred form, a starter motor connects indirectly to the shaft 1 by the use of belts, many other forms of direct and indirect driving means are usable. As an example, a separate starter motor may directly drive the shaft 1 to start the engine. Alternatively the engine may be started by way of pneumatics, forcing compressed air or other fluid into the cylinders to initiate the motion thereof. This method of starting an engine is commonly used on large trucks and ship engines. Alternatively rotation of the engine at start-up may be achieved by applying a force to the cylinder head providing means by way of friction drive or direct drive coupling.

The engine will further include as part of its electrical circuits a coil 75 and electronic ignition module 76, and alternator 78 as shown in Figure 34. The sparking of the spark plugs in the engine of the preferred form of the invention, is triggered by a Hall effect sensors mounted from the shaft 1. A disk having magnets is mounted to the shaft which rotates past the Hall effect sensors, sensing the relative rotation of the triggers there past, initiating the sparking of each of the spark plugs at the appropriate times. Many alternative ways of inducing such sparking of the spark plug are known, including the commonly used points (kettering) and reluctor mechanisms. The arrangement of these parts is well known in the automobile industry, and mayinclude equivalent alternatives. Exhaust piping 79 is most preferably connected to the exhaust ports for the ducting away of harmful exhaust gases.

As an alternative to the delivery of fuel into the cylinders, the engine may utilise exhaust gas turbos or direct drive turbos or super chargers, of which the operation is well known.

As a further alternative, instead of the mixing of air and fuel in a carburettor, the engine may utilise fuel injectors for the injection of fuel into the cylinder at the' appropriate angles of rotation of the cylinder head providing means and piston position.

Again such methods of injection are commonly known in the motor industry and need no further explanation.

As an alternative embodiment to the engine described in Figure 1, Figure 38 illustrates a cross section through an engine in which there is no relative rotation between the cylinder head providing means 5" and ported means 13". In this configuration of engine the shaft 1" is geared at each end to an annular gear 19" by planet gears 10" which are able to orbit about the shaft axis 1

A

and are able to rotate about their own axes. The rotation of the planet gears 10" is coupled with a cam Such coupling may be achieved by mounting the axle of the planet gears 10" from the cam 80". The cam 80" operates push rods 81" which in turn connect to rocker arms 82" which in turn operate inlet valves 83" and outlet valves 87" for the inlet of fuel and air into the cylinder 12" and for the exhaust of exhaust gases therefrom.

The engine of Figure 38 has two pairs of opposed pistons located at 1800 from each other from the perimeter of the piston control means The engine illustrated again may include any number of pistons and cylinders and may be double acting or single acting.

Figure 38 only illustrates one valve per cylinder, however out of plane of the cross section, at least one valve per cylinder is present such that each cylinder has at least one for inlet of air/fuel and at least one for outlet of exhaust gases. The gearing between the ported means 13" and the shaft and the shape of the cam 80" is such as to provide valve operation from the cam 80" to open the ports and close the ports to the cylinders at the appropriate times. Again this engine may be operated as a compression ignition engine, and injectors may also present in the cylinder head providing means, and again this engine may utilise exhaust gas turbos or direct drive turbos. For the retention of lubricating oil to the internal parts of the engine of Figure 38, there has been provided a crank shaft casing 89" which surrounds the pistons, crank shaft, piston control means and other associated components. This casing also provides further rigidity to the embodiment of the engine.

The valves 87"/83" are biased towards closing the ports to each of the cylinders by the use of valve springs. Opening is achieved by the push rods rocker arms and cam followers. A person skilled in the art will be able to determine an appropriate shape of the cam 80", to operate the valves at appropriate intervals of piston reciprocation.

-31 Again as the crank shaft and ports are indexed to each other by the use of the annular gear 19", planet gears 10" and shaft gearing, an appropriate ratio of gearing requires to be used, this will of course depend on the shape of the cam shaft.

Other components not illustrated in Figure 38, to operate the engine will be required. Such components include the carburettor, spark plugs for spark ignition engines and associated electric circuits.

Figure 39 is a cross sectional view through an engine similar to the engine shown in Figure 1, wherein there are two pairs of opposed pistons. The substantial difference between the configuration of the engine of Figure 39 and the engine of Figure 1 is the construction of the crank shaft and the shaft The shaft is discontinuous and locates there between the crank shaft Bearing from the crank shaft 2" is the piston control means A balancing mass 14"' is associated with each portion of the shaft Again the balancing masses 14"' balance the rotating masses and reciprocating masses in the engine.

The ported means 13"' of the engine of Figure 39 are not located in end members as in Figure 1. However a person skilled in the art will realise that this is just one alternative configuration of presenting such parts.

The gearing between the shaft and the cylinder head providing means is substantially similar to that described for the engine of Figure 1 although is duplicated on the opposite end of the shaft.

Another preferred form of the present invention consists of an engine of an embodiment different to the embodiment of the engine of Figure 1. In Figure 40 there is illustrated a partial sectional perspective view of such embodiment. Referring to Figure 41 in conjunction with the sectional view of the engine as shown in Figure the engine consists of shafts '1 which carry there between a crank shaft The crank shaft'2 is carried by crank shaft carrying members '14 secured to each shaft Again this form of engine in operation has the crank shaft '2 tracing a cone as in Figure 6 or Figure 5. The crank shaft'2 is carried by the crank shaft carrying members '14 at an incline to the axis 1 A of the shaft The crank shaft axis '2A intersects the '1A axis at point'X substantially mid way between the carrying members 14. The crank shaft'2 -32carries a piston control means '21 most preferably by using bearings '29. The bearings allow the piston control means '21 to rotate about the crank shaft axis 2

A

Carried on the perimeter of the piston control means are three pistons Figure 42 is a plan view of the pistons '20 and piston control means '21. The pistons are segments of a disc. When the engine is assembled, between each piston '20 is located a wedge block '22. The wedge blocks '22 are maintained between the pistons by the outer casing '27 and are wedged between the radial edges of each piston.

Cylinders '12 are defined by the upper and lower surfaces of the piston '20, the inner surface of the outer casing '27, the radial surfaces of the wedge blocks '22 located on either side of the piston '20, the ported means '13 and by the piston control means '21.

The piston control means '21 is substantially spherical in shape, at least in regions which form part of the cylinder '12 and has its centroid at point X. The shape of the piston control means ensures that during operation of the engine, the surface which defines part of each cylinder does not translate relative to the centroid but only rotates relative thereto. This is desirable to ensure sealing is maintained between the piston control means '21 and the ported means. Seals '25 provided in the ported means '13 seal the cylinder between the piston control means '21 and the ported means '13. Seals are also provided at the circumference of each of the pistons '20 to provide a seal between the circumference of each piston '20 and the interior surface of the outer casing '27. Seals '26 are also provided between the radial edges of each piston '20 and the radial surface of the wedge blocks '22, such seals prevent fluids from passing out of each cylinder.

Cylinders are located on both sides of each piston '20. The movement of each piston due to expansion of fuel in the cylinder causes the pistons to oscillate. Such motion induces a rotating motion of the crank shaft '2 about the shafts '1 and induces a rotating motion of the shafts. The pistons '20 and pistons control means '21 are coupled to the ported means '13 by a coupling means '23. Most preferably the coupling means '23 is a bevel gear. A bevel gear located on the piston control means meshes with a bevel gear of a large diameter located on the ported means '13. Due to such coupling, -33a rotary motion of the piston control means '21, piston'20 and wedge blocks '22 relative to the ported means '13 occurs.

The engine of Figures 40 and 41 is another preferred embodiment of the present invention wherein two cylinder chambers are situated on each side of the wobble pistons '20. However a person skilled in the art would realise that this engine may also utilise a single sided cylinder defined in part by one side of the pistons Illustrated in Figure 43 is a sequence showing the rotations of the cylinders relative to the inlet and outlet ports located in the ported means '13 of the engine of Figure 40. The sequence illustrate the steps of operation for either a three single acting or six double acting piston engine.

Following the cylinder "12 and piston "20 around, at top dead centre both inlet port "15 and outlet port "8 provide a passageway for fluids. At top dead centre exhaust fluids are virtually all expelled from the cylinder "12, and inlet fuel mixture is about to enter. As the cylinder "12 and piston "20 rotate from top dead centre to bottom dead centre, the inlet port "15 provides an inlet for fuel mixture. At substantially bottom dead centre, the cylinder "12 travels over the ported means "13 such that no ports are aligned with the cylinder "12. The inlet port "15 becomes closed by the rotation of the wedge block "22 there over. From bottom dead centre to top dead centre, the piston compresses the fuel mixture inside the cylinder "12. Thereafter as the fuel mixture combusts during the power stroke the piston travels back to bottom dead centre. At substantially bottom dead centre, and during travel of the piston "20 to top dead centre a second exhaust port provides an opening for exhaust fluids to be expelled from the cylinder "12. As the piston reaches top dead centre again a second inlet port becomes exposed to the cylinder chamber and fuel mixture is supplied through the intake into the cylinder chamber for the next sequence.

This form of engine can easily operate in different modes such as fuel injection and compression ignition having appropriate sequences as required. If it is desired to operate this engine using a diesel fuel, fuel injectors can be inserted and glow plugs may replace the spark plugs.

I -34- The engine of Figure 1 and the alternative arrangements illustrated in Figures 38 and 39 in 40 can be adapted to operate as a compression ignition engine. In the operation of the engine of the present invention as a compression ignition engine, using for example diesel as a fuel, the spark plugs 57 shown in Figures 1, 39 and 40, no longer need to be present in the embodiment. Ignition of the fuel/air mixture in a compression ignition engine is achieved by compression of the fuel/air mixture to a pressure and temperature wherein the mixture automatically ignites. The engine of the present invention can be adapted to be run as a diesel type engine by changing the compression ratios to 16: 23:1. This is achieved by having a larger crank angle or by reducing the combustion chamber volume. The compression ratio in each of the cylinders is proportional to the crank angle. In the engine of figure 1, wherein it is operating as a spark ignition engine, the crank angle is 100.

Additionally fuel injectors must be located in the ported means 15 for fuel injection into the cylinder when each piston is at top dead centre or slightly before. The injection of fuel in a compression ignition engine is well documented and does not need to be further described. Most modem diesel engines include glow plugs which are utilised at start-up. The heat which is released helps to initiate the combustion process when the engine is cold. It is envisaged that most preferably the glow plugs are located in the ported means 13, however it is noted that in the engines of Figures 1, 39 and 40, these glow plugs may not necessarily be presented to the cylinders at start-up. To this extent it will be desirable for the rotation of the cylinder head providing means 5 to be adjustable prior to start-up to present the openings to each of the cylinders to a glowplug mounted in the ported means 13. Alternatively the glow-plugs may be present in the cylinder head providing means Although herein described, the engines of the present invention have a cylinder which defines the combustion chamber of the fuel, the ported means may additionally include a pre-chamber system which communicates with the main combustion chamber through holes or apertures or the like. Such chambers are usually used in engines in which fuel is injected. The engine utilising pre-chamber systems are characterised by very good air utilisation and they are also suitable for high speed engines.

'b The combustion of fuel inside of cylinders is well documented, and many shapes of piston heads, injection angles and characteristics are known. These can all be utilised for the engine of the present invention.

Although so far herein described are engines of the present invention which operate in a four stroke cycle, all of these can be adapted to operate in a two stroke cycle. Figure 45 is a sectional view of substantially the engine of Figure 1, with slight changes to allow it to operate in a two stroke cycle. The substantial difference in the embodiment of the engine of Figure 45 when compared to the engine of Figure 41 are the ported means 13 T and the cylinders 12'. The pistons of the two stroke engine of Figure 45 have twice as many power strokes during a single revolution of the cylinder head providing means as the pistons of the engine of Figure 1. To this extent twice as many inlet ports 15 are provided in the ported means 13 T of an engine of similar geometry to that of Figure 1. In the preferred form of the two stroke engine, the exhaust gases are expelled from the cylinder 12 T through exhaust ports 8' (each cylinder having at least one) located in the perimeter of the cylinder 12

T

Such exhaust ports become open to the cylinder 12 T slightly before the piston 6 T reaches bottom dead centre. Simultaneously a fresh charges of air/fuel mixture enters into the cylinder 12

T

through inlet port 15' in the ported means 13

T

As the piston 60 returns to top dead centre, the exhaust ports 8 T are sealed by the piston and the inlet port 15 T is sealed by rotation of the cylinder head providing means to allow the air fuel mixture in the cylinder to be compressed and ignited when at or slightly before top dead centre.

Figure 45 illustrates a two stroke engine in which ignition is initiated by a spark plug 57T However as herein before described, such ignition may be achieved by compression of the air/fuel mixture.

Because the two stroke process lacks separate intake and exhaust strokes, the cylinder must be filled and emptied simultaneously.

The exhaust ports 8 T around the perimeter of the cylinder 12' connect to a single exhaust outlet of each cylinder. The combusted gases may either be expelled through each exhaust outlet into the surrounding environment, or alternatively a circumferential exhaust port providing means may be located about the exhaust outlets with centroid at 1.

V

-36the shaft axis, to provide at certain intervals of rotation of the cylinder head providing means openings for the exhaust outlet of each cylinder for the exhaust gases to be scavenged out of the cylinder 12

T

Preferably such a circumferential exhaust port providing means connects the ports therein to a single exhaust outlet to there from dispose of the harmful exhaust gases. Such a exhaust port providing means is analogous in relative rotational operation to the ported means 13

T

Figure 44 illustrates an alternative arrangement of exhausting the gases from the cylinder of the two stroke engine of Figure 45. Exhaust ports 8 T are located in the head providing means 13r at intervals such that when the piston is at bottom dead centre, ports 8' allow for the ducting away of exhaust gases from each cylinder. Although illustrated in Figure 44 are exhaust ports 8T located on a larger pitch circle diameter to the inlet ports 15', the exhaust ports 8T' may alternatively be on a smaller pitch circle diameter to the inlet ports The two stroke cycle engine may operate as a compression ignition engine, and may include alternative forms of fuel delivery to the cylinders. Again the shaft I T is indexed to the cylinder head providing means 5 T and ported means 13 T The method of start-up of the two stroke engine of the present invention can be similar to what has been described for the-four stroke engines, or any other method commonly known to a person skilled in the art. The method of cooling a two stroke engine is as substantially herein described.

For a two stroke engine, the appropriate orbital positions are such that; combusting fuel mixture is able to expand inside the cylinder 12 T forcing the piston 6 T downward during the power stroke, exhaust fluids are expelled from, and fuel mixture is displaced into the cylinder chamber when the piston is substantially at bottom dead centre, and fuel mixture is able to be compressed during the upward or compression stroke of piston 6

T

The present invention may also operate as a fluid displacement/compression machine such as a pump or a fluid driven motor. When operated as a pump or compressor a power input is supplied from eg. an electric motor to the shaft. Rotation -37of the shaft induces a rotation of the crank shaft, and causes oscillation of the pistons control means and pistons in the cylinder. Rotation of the cylinder head providing means about the shaft axis is induced from the rotation of the shaft by the gearing.

Such rotation causes a relative rotation between the cylinder head providing means and the ported means such that ports become aligned and unaligned with the cylinders at appropriate intervals. This results in induction of fluid and subsequent compression/delivery. (The opposite when driven as a motor) Figure 46 is a sectional view through the engine of Figure 1, wherein there has been included detail of the lubrication and cooling system of the engine. A suitable lubricating oil which also is able to take away heat from parts of the engine, circulated by a pumping mechanism 96 which operates from the shaft 1. The oil circulates from the pumping mechanism 96 through a conduit in the shaft 1 to the cylinder head providing means bearings 52. From the bearings 52 through an orifice in the cylinder head providing means, the oil is delivered to a jacket surrounding each of the cylinders.

The oil circulates through the jacket and out through a conduit into the crank shaft casing 98 and into the sump at the very bottom of the casing. Oil is also directed through the shaft conduit into the piston control means and out through the piston control means arms onto the back surfaces of each of the cylinders. This oil is also able to drain out into the sump. The oil in the sump is recirculated back to the pumping mechanism 96 through a conduit.

There are many forms of lubricating the engine of the present invention. It is envisaged that a high pressure low volume circulation of oil will be desirable for the lubrication of bearings, and a low pressure high volume circulation for cooling of the engine. Heat can be removed from the engine to an external body (eg air) via the end member 54. Transfer of heat within the engine is achieved by a combination of direct conduction (eg via ported means 13) and by a heat exchanger within the end members 54, taking heat away from the lubrication oil. This heat may either be then directly (assisted by the reliefs 69 shown in Fig 31) or via a cooling medium (eg radiator fluid) to an external fluid/air heat exchanger (radiator) to the surrounding air, or by any combination of the above.

Claims (11)

1. An axial piston machine having port means providing a series of intake and exhaust ports fixed relative to said port means, each connected respectively to an air intake or air and fuel mixture source and (ii) an exhaust system, a shaft rotatable relative to said port means, said shaft carrying a crank shaft having a crank axis oblique to the shaft axis, at least one cylinder defining a combustion chamber, said cylinder carried by a combustion chamber housing rotatable about the shaft axis, said combustion chamber housing being indexed at some lesser rate of rotation to the speed of rotation of said shaft and wherein each cylinder includes at least one port open to said combustion chamber, capable during operation of being brought into and out of an operative communication with each of said series of intake and exhaust ports, and, wherein each cylinder has an inlet to said combustion chamber presented for communication with said intake and exhaust ports. a piston for reciprocal motion in each said combustion chamber, a piston control means provided to said crank shaft and controlling the piston moving motion within each combustion chamber as the shaft rotates relative to said combustion chamber and each of said shaft and said chamber housing rotates relative to said port means, wherein said operative communication of said at least one port of each cylinder with each of said series of intake and exhaust ports occurs during a stroke of each piston in said combustion chamber for the axial piston machine, and wherein each said cylinder is removably secured to said combustion chamber housing.

2. An axial piston machine as claimed in claim 1 wherein said combustion chamber housing carries at least three cylinders, said combustion chamber housing rotating as an assembly about the shaft axis, each of said pistons of each of said combustion chambers being reciprocable moveable within each of said combustion chambers -39- being reciprocable moveable within each of said combustion chambers and also rotatable therewith about said shaft axis.

3. An engine as claimed in claims 1 or 2 wherein each said combustion chamber is is defined by said cylinder and in which each said piston is movable between the limits of (TDC) and (BDC) defined by the angle between the crank axis and shaft axis.

4. An engine as claimed in claim 1 wherein a connection member is provided between each of said pistons and said piston control means to control the reciprocal movement of each respective piston between (TDC) and (BDC) within its cylinder.

An engine as claimed in claim 1 wherein said port means presents a series of intake and exhaust ports at such intervals and sequences on a pitch circle diameter of a planar surface of said port means such that said at least one port of each of said cylinders, is in operative communication over a predetermined range of rotation, with said intake and exhaust ports as said combustion chamber housing rotates relative to said port means.

6. An engine as claimed in claim 5 wherein said at least one port of each said cylinders sealably rotates over said substantially planar surface and at intervals provides gas communication with said intake port(s) during the induction stroke of said piston (of a 4 stroke cycle) for air or air and fuel mixture intake into said combustion chamber, and (ii) said exhaust port(s) during the exhaust stroke of said piston (of a 4 stroke cycle) for displacement of exhaust gas from said combustion chamber, wherein sealable engagement of said at least one port of each said cylinder is provided between said intake and exhaust ports for said compression and power strokes of a four stroke cycle.

7. An engine as claimed in claim 5 wherein for each said cylinder there are two ports sealably rotatable over said substantially planar surface during compression and power strokes and at intervals provides gas communication with said intake port and said exhaust port during the induction/scavenging stroke of a 2 stroke cycle for air or air and fuel mixture intake and exhaust displacement from said combustion chamber.

8. An engine as claimed in claim 1 wherein each connection member extends from a point on the perimeter of said piston control means to it associated piston, each of said connection rods having degrees of freedom with respect to said piston control means to allow for the linear movement of each said piston within each said combustion chamber between its top dead centre (TDC) and bottom dead centre (BDC).

9. An engine as claimed in claim 1 wherein two degrees of freedom for one piston are provided at the engagement of the associated said connection member with said piston control means, a first degree of freedom being to provide radial translation of said connection member from said crank axis and a second degree of freedom to provide relative rotation between said piston control means and the associated said connection member and three degrees of freedom are provided for the remaining piston, said first and said second degree and a third degree in a direction tangentially to the rotational plane defined by said piston control means.

An engine as claimed in claim 1 wherein said combustion chamber housing is indexed by an indexing means to said output shaft such that rotation of said output shaft is proportional (but in the opposite direction) to the rotation of said combustion chamber housing (or vice versa) about said shaft axis.

11. An engine as claimed in any one of claims 4 to 10 wherein two combustion chamber housings are provided, each to present pairs of substantially opposed pistons within respective said cylinders and each of two said cylinders being rotatable about the shaft axis and each of two said cylinders located adjacent a corresponding said port means providing said series of intake and exhaust ports (an optional fuel injection means and/or air/fuel ignition means), a connection member for each pair of opposed pistons, and engaged intermediate of its distal ends with said piston control means.