WO2015027291A1

WO2015027291A1 - Engine

Info

Publication number: WO2015027291A1
Application number: PCT/AU2014/050198
Authority: WO
Inventors: Geoffrey Leonard CARR
Original assignee: Carr Geoffrey Leonard
Priority date: 2013-08-28
Filing date: 2014-08-26
Publication date: 2015-03-05

Abstract

An internal combustion engine, a charger, an engine assembly, and a method for charging an internal combustion engine are provided. The internal combustion engine includes a cylinder having one or more pistons for driving a drive shaft assembly, and a delivery system for delivering air to the cylinder through the drive shaft assembly.

Description

ENGINE

TECHNICAL FIELD

[0001 ] The present invention relates to an internal combustion engine and a charger for charging an internal combustion engine,

BACKGROUND ART

[0002] In a conventional single cylinder internal combustion engine, the expansion of burning fuel and air mixture in a combustion chamber drives the movement of a piston withi a cylinder. The piston is connected via a connecting rod to a crankshaft. The interaction between the connecting rod and the crankshaft transforms the linear motion of the piston to rotational motion of the crankshaft. An internal combustion engine ca have any number of cylinders depending on the application of the engine. (For example, four, six and eight cylinder engines are commonly used for cars.)

[0003] Many variations of the conventions internal combustion engine exist. However, many existing engines are heavy and overly complex in design, Moreover, conventional two stroke engines cannot be effectively charged by a compressed air charger such as a supercharger or turbocharger. This is because conventional two stroke engines have exhaust ports which typically become sealed after respecti ve intake ports.

[0004] Embodiments of the present invention provide an improved Internal combustion engine that achieves a high power to weight ratio. Moreover, embodiments of the present inventio provide a two stroke internal combustion engine capable of being charged effectively by a compressed air charger.

[0005] In some applications, a compressed air charger such as a turbocharger or a supercharger is coupled to an engine to provide additional air to the combustion chamber of the engine so tha more power can be produced by the engine. However, the turbocharger or supercharger can often provide inconsistent outpu depending on the operation of the engine.

[0006] Embodiments of the present invention also provide an improved, charger for charging an internal combustion engine, which is capable of providing consistent output to the internal combustion engine,

[0007] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part, of the common general knowledge in the art in Australia or in an other country.

SUMMARY OF INVENTION

[0008] Accordin to one aspect of the invention, there is provided an internal combustion engine includin

a. cylinder having one or more pistons for driving a drive shaft assembly, and

a delivery system for delivering air to the cylinder throug the drive shaft assembl .

[0009] Advantageously, the configuration of the internal combustion engine to enable air to be delivered through the drive shaft assembly may enable the engine to be of a more streamlined, compact and light weight design.

[0010] The drive shaft assembl may include a hollow drive shaft. The delivery system may deliver air to the cylinder through the hollow drive shaft. The hollow drive shaft may include two parts. The two parts of the hollow drive shaft may be removably connected to one another. The two parts of the hollow drive shaft may be removably connected to one another via a threaded connection and nut assembly. The hollow drive shaft may be located along a central elongate axis of the internal combustion engine.

[0011] The one or more pistons may be operatively adapted to drive the hollow shaft in cycles of rotation such that an outlet of the hollow drive shaft aligns with an. inlet of the cylinde once per cycle of rotation to allow air to pass from the hollo drive shaft into the cylinder,

[0012] The air delivery system may deliver air t the cylinder from a charger for charging the internal combustion engine. The charger may include a supercharger and/or. a turb.ochar.ger.

[0013] The internal combustion engine may be a two stroke engine.

[0014] The cylinder may include an air induction port for allowing air to be injected into the cylinder therethrough at a start of a compression stroke of a cylinder cycle, a fuel injection port for allowing fuel to be injected into the cylinder therethrough at an end of the compression stroke of the cylinder cycle, and an exhaust port to allowing exhaust to pass out of the cylinder therethrough during a combustion stroke of the cylinder cycle.

[0015] The drive shaft assembly may include a reciprocating member for reciprocating along a predefined path, and a rotating member configured for engagement with the reciprocating member such that, reciprocating motion of the reciprocating member is transformed into rotation of the rotating member. The rotation of the rotating member may drive the hollow drive shaft in cycles of rotation.

[0016] The reciprocating member may define an annular channel for receiving an annular lip of the rotating member.

[0017] The internal combustion engine may include one or more connecting rods connecting the one or more pistons with the drive shaft assembly such that motion of the pistons can be transferred to reciprocating motion of the reciprocating member. Each connecting rod may have a spherical end portion configured for engagement with the reciprocating member, the spherical end portion being configured to facilitation relative motion between the reciprocating member and each connecting rod.

[0018J The internal combustion engine may include an operating chamber for housing at least a portion of the reciprocating member and the corresponding rotating member. The operating chamber defines an infernal elongate groove for receiving a slider of the reciprocatin member and allowing the slider to slide back and forth within the elongate groove so as to guide the reciprocating motion of the reciprocating member,

[0019] The internal combustion engine may further define an oil reservoir for holding excess oil collected in the operating chamber, the oil reservoir includes an oil collection system for collecting the excess oil. The oil collection system may include spring loaded ball bearings located along a floor of the elongate groove. The sliding motion of the slider may push oil past the ball bearings so that excess oil collected in the elongate groove is pushed into the oil reservoir.

[0020] The operating chamber may define a further internal elongate groove on an opposite side of the operating chamber for receiving a further slider on an opposite side of the reciprocating member. An oil collection system may be located along a floor of eac internal elongate groove.

[0021] Advantageously, the oil reservoir may collect excess oil through the oil collection system when the internal combustion engine is operating in any orientation. This allows the internal combustion engine to be suitably used in aviation applications, for example, in aerobatic flights, in which the orientation of the internal combustion engine may often change- with the flight path.

[0022] The drive shaft assembly may include a further reciprocating member for reciprocating along a predefined path, and a further rotating member configured for engagement with the further reciprocaling member such that reciprocating motion of the further reciprocating member is transformed into rotation of the further rotating member. The reciprocating member and the corresponding rotating member may be located adjacent an opposite end o the cylinder to the further reciprocating member and the corresponding further rotating member.

[0023] The internal combustion engine may include a further operating chamber to house at least a portion of the further reciprocating member and the farther rotating member. The further operating chamber may be located on an opposite end of the cylinder to the operating chamber.

[0024] The internal combustion engine may include two or more cylinders arranged in parallel to one another around the hollow drive shaft. The internal combustion engine may include five cylinders evenly positioned around the hollow drive shaft to for a. cylinder block.

[0025] Each cylinder may include pair of opposed pistons,

[0026] Advantageously, .arranging the cylinders around a central drive shaft may further enable the internal combustion engine to be of compact, low profile and light weight design. The arrangement of the opposed pistons and the drive shaft assembly is also advantageously configured to achieve a high power output.

[0027] Eac piston may include a sealing ring located around a body of the piston. Advantageously, the sealing rin prevents excess lubricant oil from entering into a combustion chamber of the cylinder.

[0028] The internal combustion engine further include a cooling jacket for holding cooling fluid. The cylinder block may include the coolmg jacket. The internal combustion engine may include a spark plug and/or a laser igniter .

[0029] The internal combustion engine may further comprise an actuator, for translating the one or more pistons to change a compression ratio of the cylinder. According to certain embodiments, an actuator in the form of piston may translate a drive shaft assembly of the engine, and in tur translate the pistons, to change the compression ratio of the cylinder.

[0030] The internal combustion engine may comprise a second actuator configured to rock a face of the rotating member along a lateral axis. In particular, the second actuator may rock the face in concert with, or independently of the reciprocaling member, in order to prevent port timing changes of the engine caused by translation of the pistons.

[0031] Furthermore, the internal combustion engine may comprise a third actuator configured to vary a position of the rotating member_* i a rotational direction, relative to the further rotating member.

[0032] According to another aspect of the invention, there is a method of operating an inte na! combustion engine, the method including

driving a drive shaft assembly using one or more pistons in a cylinder, and

delivering air to the cylinder through the drive shaft assembly.

[0033] Accordin to another aspect of the invention, there is provided a charger for chargin an internal combustion engine with compressed air, the charger including

a compressor for providing compressed air to the internal combustion engine,

a first driver for driving the compressor, the first driver being configured to receive power from a drive shaft of the engine, and

a second driver for driving the compressor, the second driver being configured to receive power from exhaust of the engine,

the first driver and the second driver forming a single drive unit such tha when the operation of the engine transitions from low revolution pe minute (RPM) to high RPM, load from the compressor shifts from the first driver to the second driver.

[0034] Advantageously, the compressor may be driven consistently by the first and second drivers, thereby enabling the charger to provide a more consistent output to the internal combustion engine.

[0035] The first driver ma be coupled with the second driver. The first driver may include an output shaft which engages with a output shaft of the second driver.

[0036] The first driver may include art input drive configured to engage with the drive shaft of the engine. The first driver may further include a gearbox for carrying out, speed and torque conversions between the input drive and the output shaft of the first driver.

[0037] The second driver may include an exhaust impeller configured to be driven by the exhaust of the engine, The .exhaust impeller may drive the output shaft of the second driver.

[0038] According to a further aspect of the invention, there is provided an engine assembly including an internal combustion engine as previously described coupled to a charger as previously described.

[0039] According to yet another aspect of the invention, there is provided a method fo charging an internal combustion engine with compressed air, the method including providing compressed air to the internal combustion engine,

driving the compressor using a first driver, the first driver being configured to receive power from a drive shaft of the engine, and

driving the compressor using a second driver, the second driver being configured to receive power from exhaust of the engine,

wherei the first driver and the second driver forms a single drive unit such that when the operation of the engine transitions from low RPM to high RPM, load from the compressor shifts from the first driver to the second driver.

[0040] Any of the features described herein can be combined in an combination with any one or more of the other features described herein within the scope of the invention.

[00 1] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the commo general knowledge,

BRIEF DESCRIPTION OF DRAWINGS

[0042] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled i the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to a number of drawings as follows:

[0043] Figure 1 illustrates a side section view of an internal combustion engine according to an embodiment of the invention.

[0044] Figure 2A illustrates a perspective view of the internal combustion engine of Figure 1.

[0045] Figure 2B illustrates a perspective view of the internal combustion engine of Figure 2 A with its outer covers removed,

[0046] Figure 3 illustrates a front view of a reciprocating member of the internal combustion engine of Figures 1, 2 , 2B.

[0047] Figure 4 illustrates a two part bracket fo mounting a connecting rod of the internal combustion engine to the reciprocating member of Figure 3. [0048] Figure 5 illustrates a rotating member of the internal combustion engine of Figures 1 , 2A, 2B.

[0049] Figure 6 illustrates the internal structure of the rotating member of Figure 5.

[0050] Figure 7 illustrates connections between connecting rods and the reciprocating member of Figure 3.

[0051] Figure 8 illustrates an oil collection system of the internal combustion engine of Figure I . 2A and 2B.

[0052] Figure 9 illustrates a charger for charging an internal combustion engine according a embodiment of the present invention.

[ 0053] Figure 10 illustrates a side section view of an internal combustion engine system according to an alternative embodiment of the present invention,

[0054] Fig 1 la illustrates a perspective view of a cylinder block of the engine of Figure 10, according to an embodiment of the present invention.

[0055] Fig 1 l b illustrates an end vie w of the cylinder block of t he engine of Figure 10.

[0056] Fig l ie illustrates a side view of the cylinder block of the engine of Figure 10.

[0057] Figure 1 Id illustrates a perspective cutaway view of the cylinder block of the engine of Figure 10.

[0058] Figure 12a illustrates a end cutaway view of the c linder block of the engine of Figure 10, from an intake end of the engine.

[0059] Figure 12b illustrates a perspecti ve cuta way view of the cylinder block of the engine of Figure 10, from the intake end of the engine.

[0060] Figure 12c illustrates an end cutaway view of the cylinder block of the engine of Figure 1 , from an exhaust end of the engine.

[^'0061] Figure 12d illustrates a perspective cutaway view of the cylinder block of the engine of Figure 10, from the exhaust end.

[0062] Figure 13 is a perspective view of the internal combustion engine of the engine of Figure 10 with the cylinder block removed. [0063] Figure 14 is an exploded perspecti ve view of a portion of the internal combustion engine of the engine of Figure 10 wit the central cylinder block removed.

[0064] Figure 15 is an exploded perspective view of a portion of a dri ve shaft assembly of the engine of Figure 10, according to an embodiment of the present invention.

[0065] Figure 16a is a perspective view of the hollow drive shaft of the engine of Figure 10, according to an embodiment of the present invention.

[0066] Figure 16b is an end view of the hollow drive shaft of the engine of Figure 1.0.

[0067] Figure 16c is a perspective cutaway view of the hollow drive shaft of the engine of Figure 1 .

[0068] Figure 1.7 is a perspective cutaway sectional view of the interna! combustion engine of Figure 10 with the cylinder block removed, according to an embodiment of the present invention.

[0069] Figure 18a illustrates a sectional cutaway view of the engine of Figure .10 in a low compre ssion configuration.

[0070] Figure 18b illustrates a side cutaway view of the engine of Figure 10 in a hig compre ssion conf i guration ,

DESCRIPTION OF EMBODIMENTS

[0071] Figure 1 illustrates a side section view of an internal combustion engine 100 according to an embodiment of the present invention. The internal combustion engine 1.00 includes a central cylinder block 102, two end operating chambers 104, 106 located on opposite ends of the cylinder block 102, and a middle hollow drive shaft 108 located along a central elongate axis of the engine 100.

[0072] The cylinder block 102 includes five cylinders (only two cylinders 1.10a, 1.1.0b shown) equally spaced around the hollow drive shaft 108. Each cylinder 110a, 1 10b houses a pair of opposed piston 1 14a, 1.14b, 1 14c, 114d. Each pair of opposed pistons 1 1.4a, 1 14b, 1 14c, 114d are linearly movable within each respective cylinder 11.0a, 1 10b. The linear movement of the pistons 1.14a, 1 :14b, 1 14c, ll4d drives the hollow drive shaft 108 through a drive shaft assembly 116.

[0073] The drive shaft assembly 116 includes the hollow drive shaft 108 and a pair of reciprocating members 1 18a, 1 18b. Each reciprocating member 118a, 1 8 is mounted on the hollow drive shaft 108 adjacent opposite ends of the cylinder block 102. The drive shaft assembly 1 16 further includes a pair of rotating members 120a, 120b, Each rotating member 1.20a,. 120b is configured t engage with a respective reciprocating member 118a, 1.18b. Each reciprocating member 1 18a, 1 18b and the corresponding rotating member 1.20a, 120b is housed within a respective operating chamber 104, 106. Each operating chamber 104, 106 defines a pair of elongate grooves 122a, 122b, 124a, 124b. Each pair of elongate grooves 122a, 122b, 124a, 124b is located on opposite sides of the respective operating chamber 104, 106, Each reciprocating member 11.8a, 1. 18b includes a pair of slider blocks 1.26a, 126b, 128a, 128b configured to be received within respective elongate grooves 122a, 122b, 124a, 124b. The movement of the slider block 126a, 1.26b, 128a, 128b within the respective elongate grooves 122a, 122b, 124a, 124b guide the reciprocating motion of the respective reciprocating members 1.18a, 1 18b.

[0074] Eaeh piston 114a, 1.14b, 1 14c, 1 14d is piyotally connected t a respective reciprocating member 118a, 118b via a connecting rod 1 12a, 1 ! 2b. 1 12c, 1 1.2d such that linear movement of the pistons 114a, 1.14b, 1 14c, 114d is transformed into reciprocating movement of the reciprocating members 118a, 11.8b. The reciprocating movement of the reciprocatin members 1 18a, 118b cause the rotating members 12.0a, 120b to rotat and thereb drive the hallow drive shaft 108 in rotation.

[0075] The internal combustion engine 100 is a two stroke engine. During operation, each cylinder cycle includes a compression stroke and a combustion stroke. The operation of the internal combustio engine 100 will be discussed in further detail below in relation to a single cylinder 1 10a. It is to be understood that the other cylinders in the cylinder block 102 operate according t the same principle as that described belo in relation to cylinder 11.0a.

[0076] Cylinder 1.10a includes an air induction port 130a, a fuel injection port 130b, an exhaust port 130c, and an air inlet 130d. At the start of a compression stroke, induction air is injected into the combustion chamber 134 (defined b a volume between the pair of opposed pistons 114a, 1.1.4b). At the same time, an outlet 132 of the hollow drive shaft 108 is aligned with the air inlet 130d of the cylinder 110a, and additional induction air is delivered via the hollow drive shaft 108 from a compressed air charger (not shown) into the combustion chamber 134. The injection of induction air via the air induction port 130a and the air inlet 130d pushes exhaust from a previous cycle out of the combustion chamber 134 via exhaust port 130c.

[0077] During the compression stroke, the reciprocating members 1 18a, 118b push the pistons 1 14a, 1 14b towards each other such that air induction port 130a and the exhaust port 130c are sealed by each piston 1 14a, 1 3.4b and the air in the combustion chamber 1.34 is compressed. After the exhaust port 130c is sealed, additional air can be delivered to the combustion chamber 134 via inlet 130d to further, pressurize the combustion chamber 134. The movement of the reciprocating members 1 18a, 1 18b causes the respective rotating members 120a, 120b to axially rotate and thereby turn the hollow drive shaft 108. As the drive shaft 108 is rotated, the outlet 132 turns away from the inlet 130d and air no longe flows between the hollow drive shaft 108 and the combustion chamber 134.

[0078] As the pistons 114a, 114b reach Top Dead Centre, fuel is injected through fuel injection port 130b and combustion occurs within the combustion chamber .134. If the fuel is petrol , a spark plug (not shown) is used to initiate combustion, if the fuel is diesel, combustion is initiated automatically via compression of the fuel and air mixture within the combustion chamber 134.

[0079] During the combustion stroke, expansion of the fuel and ai mixture within the combustion chamber 134 pushes the pistons 114a, 3.14b apart. The pistons 114a, 114b push one side of each reciprocating member 118a, 1 18b away from the cylinder block 102 thereby causing an opposite side of each reciprocating member 118a, 1.18b to move towards the cylinder block 1.02 to drive another cylinder 110b into its compression stroke.

[0080] At the end of the combustion stroke for cylinder 3.10a, the pistons 1 14a, 114b move past the air induction port 130a and the exhaust port 130c, the outlet 132 of the hollow drive shaft 108 becomes realigned with th air inlet 130d of the cylinder 110a, induction air is injected into the combustion chamber 134 via air induction port 130a and inlet 130d, which pushes exhaust out of the combustion chamber 134 through the exhaust port 130c. At the same time, cylinder 1.1.0b reaches the end of its compression stroke and moves towards the combustion stroke. As cylinder 110b initiates the combustio stroke, combustion of the ai and fuel mixture causes pistons i 14c, 114d to move apart and push one side of the reciprocating members 11 a, 1 18b away from the cylinder block 102, which moves an opposite side of the reciprocating members 1 18a, 118b towards the cylinder block. The movement of the opposite side of the reciprocating members 118a, 118b towards the cylinder block 102 pushes the pistons 114a, 114b towards one another in cylinde 110a, and cylinder 110a re-enters its compression stroke in a second cycle. The compression and combustion strokes are repeated in each successive cylinder cycle.

[0081 ] The motion of the pair of opposing pistons in each of the five cylinders move in succession to one another and the sequence of movements of the pistons cause the reciprocating members 1 1.8a, 1 18b to reciprocate or move back and forth as guided by the sliders 125a, 326b, 128a, 128b slidin withi the respective elongate grooves 122a, 122b, 124a, 124b. The .reciprocating motion of the reciprocating members 1.18a, 1.18b cause the respective rotating members 120a, 120b to rotate. The rotation of the rotating members 3.20a, 120b drives the hollow drive shaft 108 in cycies of rotation such that the outlet 132 of the drive shaft 108 becomes aligned with an inlet of each of the five cylinders once per cycle of rotation. The rotation of the drive shaft 108 is tuned such that the outlet 132 of the drive shaft 108 is aligned with an inlet 130d of a cylinder 1 10a as the cylinder 1 30a transitions between the combustion stroke to the compression stroke,

[0082] The drive shaft 108 includes a first part 136 and a second part 138. The second part 138 of the drive shaft 108 is sealed at one end 140 such that the engine 100 can continue to operate even if the first part 136 becomes faulty or broken. The first part 136 is connected to the second part .138 via a threaded connection 142 and nut (not shown).

[0083] Each piston 11.4a, 114b, 114c, 11.44 includes a sealing ring 111 located adjacent one end such that exces lubricant oil from the operating chambers 104, 106 cannot enter the combustion chamber 134 of each cylinder 1 10a, and the air and fuel mixture in the combustion chamber 134 does not escape into the operating chambers 104, 106.

[0084] The cylinder block .102 further includes a cooling jacket 103 for holding cooling fluid. The cooling fluid facilitates cooling of the cylinders 110 during operation. The cooling jacket 103 is completely sealed around the cylinder block 102 so as to eliminate requirement for any gaskets (typically used in conventional engines) and potential leaks.

[0085] Figure 2A is a perspective view of the internal combustion engine 100. As previously described, the internal combustion engine 100 includes a cylinder block 120 and tw operating chambers 104, 106. Each operating chamber 104, 106 is disposed on an opposite side of the cylinder block 120. The air induction port 130a, fuel injection port 130b and the exhaust port 1.30c for each cylinder are spaced around the cylinder block 120 as shown in Figure 2A.

[0086] Figure 2B is a perspective view of the internal combustion engine 100 with its outer casing removed. As previously described, the combustion engine 100 includes five cylinders. Each cylinder houses a pair of opposed pistons 114, Each piston 114 is connected via a connectin rod 1 12 to a respective reciprocating member 118a, 118b. The reciprocatin motion of each reciprocating member 3 18a, 118b is guided by a pair of sliders 126a, 126b, 128a, 128b (only one slider shown on each reciprocating member 1 18a, 118b) configured to slide back forth within respective elongate grooves 122a, ,122b, 124a, 124b (not shown).

[0087] Figure 3 illustrates a front view of a reciprocating member 1 18a of the internal combustion engine 100. The reciprocating member 1 18a includes a circular disk or plate 144, Slider blocks 126a, 126b are provided on opposite sides of the circular plate 144 to guide the movement of the reciprocating member 1 18a along a path defined by the elongate grooves 122a, 1.22b, 124a, 124b as previously described.

[0088] The plate 144 defines a central opening 146 for receiving the hollow drive shaft 108. The central opening 146 is sized to allow the hollo drive shaft .108 to freely rotate therein.

[0089] The circular plate 144^■further defines five aperture 148a, 148b, 148c, I48d. 148e. Each aperture 148a, 148b. 148c, 148d, 148e is sized to receive one end of a connecting rod 112 (described in further detail with reference to Figure 7). To facilitate the connection between the connecting rods 1 12 and the circular plate 144, brackets 150a, 150b, 150c, 150d, 150e are provided for the attachment of each connecting rod 112.

[0090] Figure 4 is a perspecti ve view of one of the brackets 150 shown in Figure 3 , Each bracket 150 includes two parts or halves 152a, 152b. Once the ends of the connecting rods 112 are received in the apertures 148a, 148b, 148c, 148d, 148e, the bracket halves 152a, 152b are placed around each end of the connecting rods 112 to secure the connecting rod 112 to the circular plate 144, The bracket 150 can be secured to the circular plate 144 using any one or more of bolts, nuts, screws, pins, rivets, nails, clips, clamps, or any suitable fastener.

[0091] Figure 5 is a perspective view of a rotating member 120 of the internal combustion engine 100. The rotating member 120 includes a base portion 154 and a head portion 156. The rotating member 120 defines a cylindrical hollow portion 158 along a rotational axis of the rotating member 120, The hollow portion 158 is sized to receive the drive shaft 108, The wails of the hollow portion 158 engage with walls of the drive shaft 1.08 so that rotation of the rotating member 120 rotates the drive shaft 108.

[0092] The head portion 154 has a substantial fmstoconical shape. One side of the head portion 154 is angled with respect to a plane normal to the rotational axis of the head portion 154 so as to define circular face 160. The head portion 154 also define a annular groove 162 generally concentric to the cross section of the cylindrical hollow portion 158, The annular groove 1 2 is configured to receive the annular protrusion on the bottom of the circular plate 144, and allow the rotating member 120 to rotate with respect to the circular plate 144.. [0093] As shown in Figure 6, the head portion 156 includes internal splines 162, The splines 162 advantageously reduce the weight of the head portion 156 whilst providing the head portion 156 with, the required physical properties, such as strength and toughness. The splines 162 facilitate mass balance of the head portion 156.

[0094] The attachment, between the connecting rods 112, a reciprocating member 1 18 and a rotating member 120 will now be described with reference to Figure 7, As shown in Figure 7, each connecting rod 1 12a, 1 12b (only two of five connecting rods are shown) include a spherical end portion 164a, 164b, Each end portion 1 4a, 164b is received in. a respective aperture 148a, 148b, 148c, 148d, 148e of the circular plate 144, Each connecting rod 112a, 112b is the secured in place using brackets 150a, 150c mounted around a periphery of the respective spherical end portions 164a, 164b. The rotating member 120 is rotatable relative to the reciprocating member 1 18 and connecting rods 112a, 112b.

[0095] The circular plate 144 further defines a annular- side channel 166 adjacent a periphery of the circular plate 144 for receiving an annular lip 17 of the rotating member 120 (see Figure 1). Once the annular lip 172 of the rotating member 120 is received in the side channel 16 of the reciprocating member 118, a circular backing plate 168 is secured to a peripheral ridge 174 of the circular plate 144 vi fasteners 176. The fasteners 176 can include any one or more of bolts, nuts, screws, pins, rivets, nails, clips, clamps, or the like. The circular backing plate 168 defines a central opening 178 so that the head portion 156 of the rotating member 120 can protrude therethrough (see Figure 1).

[0096] Due to the unique shape of the head portion 156 of the rotating member 120, as the reciprocating member 118 moves back and forth along linear path defined by the elongate groove 122a, 122b or 124a, 124b, the reciprocating motion of the reciprocating member 1.18 turns the rotating member 120 about its rotating axis. As the rotating member 120 rotates relative to the reciprocating member 118, the annular lip 172 of the rotating membe 120 slides within the annular side channel 1 6 of the circular plate 144,

[0097] Figure 8 illustrates a portion of an oil scavenge system 180 of the internal combustion engine 100. The oil scavenge system 180 includes an oil return line 182 which collects lubricating oil from moving parts and joints of the internal combustion engine 100 via ducts .188 provided in throughout the engine 100. For example, ducts 188 are provided in the reciprocating members 118 and connecting rods 112 as shown in Figure 7.

[0098] More particularly. Figure 8 illustrates a slider 126 located within an elongate groove 122 of an operating chamber 104. Along a floor 184 of the elongate groove 122, the oil collection system 180 provides multiple spring loaded ball bearings 186 (only four shown). Durin operation of the engine 100, excess oil collects in the elongate groove 122. As the slide 1.26 slides back and forth within the elongate groove 122, the slider 126 pushes excess, oil past the ball bearings 186 into the oil return line 182Whil.st only a portion of the oil collection system 180 is described with reference to Figure 8, it is understood that any number of sprin loaded ball bearings can be used along a. floor of each elongate, groove 122, 124 of the operating chambers 104, 106.

[0099] Advantageously, the oil return linl82 of scavenge system 180 can collect excess oil through the oil collection system 180 when the internal combustion engine 100 is. operatin in any orientation. This allows the mternal combustion engine 100 to be suitably used in aviation applications, for example, i acrobatic flights, in which the orientation of the internal combustion engine 100 would frequently change with the flight path.

[00100] Whilst only the operation of one side of the drive shaft assembly has been described above, it is to be understood, that the operation of the side of drive shaft assembly associated with operating chamber 104 mirrors the operation of the side of the drive shaft assembl associated with operating chamber 106.

[00101] Advantageously, arranging the cylinders 110 in parallel around the central hollow drive shaft 108 allows the internal combustion engine 100 to achieve a compact, low profile and lightweight design. The drive shaft assembly 1 16 is also advantageously configured. to achieve a high power output. The internal combustion engine 100 therefore has a higher power to weight ratio than many conventional engines.

[0 102] Moreover, the manner in which the combustion chambers 134 are contained between opposed pistons 114 and between the operating chambers 104, 106 eliminates the need for any heavy blocks to carr high stresses exerted between a manifold and crankcase support bearings of a conventional internal combustion engine. The. arrangement of the opposed pistons 1 14 also eliminates the need for a heavy manifold, which is commonly used in conventional internal combustion engines.

[00103] Furthermore, as each cylinder 110a defines an air induction port 13.0a, a fuel induction port 130b, and an exhaust port 130c, camshafts, camshaft drives, valves, valve springs, which are commonly used in conventional engines' are also eliminated.

[00104] As the operatio of the hollow drive shaft 308 is timed and tuned to deliver induction air into the combustion chamber 134 of each cylinder 1 10, individual cylinder intake runners commonly used in conventional engines are also eliminated.

[00105] In the combustion engine 100, the operation of the reciprocating members 1 18 and the respective rotating members 120 convert linear motion of the pistons 1 14 to rotary motion of the hollow drive shaft 108. The operation of the reciprocatin members 118 and the respective rotating members 120 thereby provides the equivalent function of a crankshaft in a conventional engine. However, unlike the connecting rods in a conventional engine, which pivot relative to the pistons across large angles: to drive the crankshaft, only small pivotal movement of the connecting rods 112 (relative to the pistons 112) in the present engine 100 is required to drive the drive shaft assembly 116. The relatively smaller pivotal movement required for the connecting rods 112 in the present engine 110 advantageously reduces stress and strain caused, by high side loads on the pistons 114 and thereby reduces wear and tear of the pistons 1 14 as well as the connecting rods 112 ,

[00106] The internal combustion engine 100 can advantageously be used in a wide range of applications including all modes of transpor and variou machinery and plant equipment,

[00107] Figure 9 illustrates a charger 200 according an embodiment of the present invention for charging an internal combustion engine such as the internal combustion engine 100 as described above with compressed air, The operation of the charger 200 will now be described with reference to the internal combustion engine 100. However, it is to be understood that the charger 200 can be used to charge any suitable internal combustion engine.

[00108] The charger 200 includes a centrifugal compresso 202 for providin compressed air t the internal combustion engine 100. The compressor 202 extracts ambient air via intakes 204a, 204b and compresses the ambient air to provide compressed air to the engine 100. The compressed air is delivered to the combustion chambers 134 of each cylinder 110 via the hollow drive shaft 108 and air induction ports 130a as previously described.

[00109] The charger 200 includes a first driver 206 for driving the compressor 202. The first driver 206 is configured to receive power from a drive shaft of the engine 100 (not shown). The charger 200 also includes a second driver 208 for driving the compressor 202. The second driver 208 is configured to receive power from the exhaust of the engine 100.

[001.10] The first driver 206 includes an input drive 210 configured to be driven by the hollow drive shaft 108 of the engine 100. The input drive 210 can be coupled to the drive shaft 108 using any one or more of a serpentine belt, tooth belt, one or more gears, chains or any other [00111 J The first driver 206 further includes a gearbox 212 and an output drive shaft 214, The input drive 210 is coupled to the output chive shaft 214 via the gearbox 212, The gearbox 21 catties out speed and torque conversions between the input drive 210 and the output drive shaft. 214, The output drive shaft 214 is also coupled to the compressor 202 such that rotation of the output drive shaft 214 can drive the compressor 202.

[00112J As the engine 100 is turned on, the hollow drive shaft 108 of the engine 100 drives the input drive 210 of the driver 206, which drives the output drive shaft 214 via gearbox 212. The output drive shaft 214 in turn drives the compressor 202, which delivers compressed air to the engine 100, Accordingly, the first driver 206 essentially acts as a supercharger for the internal combustion engine 100.

[00113] The second driver 208 includes an exhaust inle 216, an exhaust impeller 218 driven by exhaust from the exhaust inlet 21 , and an output drive shaft 220, Once the engine 100 turns on, exhaust emitted from the exhaus port 130c of each cylinder 110 is delivered to the exhaust inlet 216. The flow of the exhaust turns the exhaust impeller 218 to drive the output drive shaft 220.

[00114] The output drive shaft 220 of the second driver 208 is coupled to the output drive shaft 2,14 of the first driver 206 either directl or via a gearbox 222. The gearbox 222 carries out speed and torque conversions between the output drive shaft 220 of the second drive 208 and the output drive shaft 214 of the first drive .206. The gearbox 222 can be a step-down gearbox.

[001.15] The second driver 208 can there-fore drive the- compressor 202 via the output drive shafts 220, 214. The second driver 208 essentially acts as a turbocharger for the internal combustion engine 100.

[00116] As the engine 100 is turned on, time is required for the engine to transition from low RPM (Revolutions per Minute) to high RPM. Initially, as the engine 100 operate at low RPM, power from exhaust emitted from die engine 100 is low. During the low RPM period, the second charger 208 provides little output. However, the drive shaft 108 of the engine 100 provides sufficient power to drive the first, charger 206. Accordingly, the compressor 202 is predominantly driven by the first charger 206 when the engine is operating at low RPM.

[00117] As the engine 100 transition from low RPM to high RPM, power from the exhaust of the engine 100 increases so that more power is delivered to the exhaust impeller 218 of the second charger 208, which increases the power output of the second charger 208, As output from the second charger 208 increases with increasing RPM, more power is delivered from the second charger 208 to the compresso 202 and load from the compressor 202 shifts from the first drive 206 t the second driver 208.

[00118} At high RPM, load from the compressor 202 can he completely shifted t the second driver 208 and the first charger 206 does not carry any load from the compressor 202. Moreover, excess power from the second charger 208 can be back driven to the engine 1.00 via the output drive shafts 220, 214, gearbox 212 and input: drive 210.

[00119] As the engine 100 transitions from high RPM to low RPM, power from the exhaust of the engine 100 reduces, and load from the compressor transfers from the second charger 208 back to the first charger 206.

[00120] Conventional superchargers can operate with sufficient power output at low RPMs, but cause power drains on the engine at high RPMs. Conventional turbochargers can provide sufficient power output at high RPMs without causing power drains on the engine. However, as conventional turbochargers rely on exhaust from the engine fo input, conventional turbochargers typically lack sufficient power at low RPMs. By combining the first driver 20 (which effectively operates like a supercharger) and the second driver 208 (which effectively operates like a turbocharger) into a single drive unit, the charger 200 combines the advantages of a supercharger and a turbocharger,. whilst eliminating the disadvantages of the supercharger and turbocharger,

[00121 ] Advantageously, the compressor 202 can be driven consistently by the first and/or second dri ers 206, 208 across a wide range of RPMs to thereby provide consistent output to charge the internal combustion engine 100 during operation.

[00122] Further, conventional superchargers typically cause a 20% t 25% power drain on the engine at high RPM. As the first driver 206 can be completely unloaded at high RPM, the power drain of conventional superchargers can be eliminated. Also, as excess power from the second charger 208 can be back driven via the gearbox 212 into the engine 100, engine power recovery that is not possible with conventional supercharger or turbocharger setup can be achieved with the present invention,

[00123] Moreover, combining the first driver 206 and the second driver 208 into a single unit eliminates duplication of compressors, air filters, intake plumbing and intereoolers. By coupling the output drive shaft 220 of the second driver 208 directly t the output drive shaft 214 of the first driver 206, an exhaust waste gate typically used in conventional chargers is eliminated.

[00124] An internal conibustion engine 100 according to another embodiment of the invention can include any suitable type of connecting rods 112 for connecting the pistons 114 t the drive shaft assembly 1.16. For example, conventional connecting rods having universal joint style ends or ball end bearing style connectors can be used instead of the spherical end portions 164.

[00125] In some embodiments, the internal combustion engine 100 can be configured to operate a a multi-fuel engine. In these embodiments, various types of fuel can be injected into the engine 100 via the fuel injection ports 130b at the end of each compression stroke.

[00126] In other embodiments, the internal combustion engine 100 can have any suitable number of cylinders 110. For example, the engine 100 may have two, three, four, five, six, seven, eight of more cylinders 110. The cylinders 110 can be arranged in parallel surrounding the hollow drive shaft 108.

[00127] Figure 10 illustrates a side section view of an internal combustion engine system 1000 according to an embodiment, of the present invention. The internal combustion engine system 1000 includes an internal combustion engine 1000a, a charger 1000b coupled to the internal combustion engine 1000a, an intercooler lOOOe coupled to charger 1000b, and an inlet manifold lOOOd coupled betwee the intercooler 1000c and the internal combustion engine 1000a,

[00128] The internal combustion engine 1000a is similar t the internal combustion engine 100 of Figure 1 and includes a centra] cylinder block 1020, two end operating chambers 1040, 1060 located on opposite ends of the cylinder block 1020, and a middle hollow drive shaft 1080 located along a central elongate axis of the engine 1000a.

[00129] The cylinder block 1020 includes a plurality of cylinders 1100 equall spaced around the hollow drive shaft 1080, each cylinder 1100 housing a pair of opposed pistons 1140. Linear movement of the pistons 1140 is transformed into reciprocating movement of reciprocating members 1180a, 1 180b, and the reciprocating movement of the reciprocating members 1 .180a, 1180b causes rotating members 1200a, 1200b to rotate and thereby drive the hollow drive shaft 1080 in rotation.

[00130] As discussed in further detail below, the engine 1000a includes variable cylinder compression. In particular, the reciprocating member 11.80a can be translated ^'towards each other such that the opposed pistons 1 140 are closer to each other, thus increasing a compression ratio of the cylinders 1 .100.

[00131] The engine 1000a includes a main gear 1005, for driving the charger 1000b by gearing 1010, and an exhaust turbine 1015 for additionally driving the charger 1000b. in particular, the charger 1000b includes a radial compressor 1025 for compressin air from a air intake. As such, the charger 1000b is driven both by exhaust gases from the engine 1000a (in a similar manner to a turbocharger) and by rotation of the gearing 1.010 in a similar manner to a supercharger. The main gear 1005 also functions as a flywheel and includes an integrated torsional damper.

[00132] The charger 1000b can be similar or identical to the charger 200 of Figure 9. The radial compressor 1025 can be drive consistently by the first and/or second drivers 206, 208 across a wide range of RPMs to thereby provide consistent output to charge the internal combustion engine 1000a during operation.

[00133] The inle manifold lOOOd is coupled to an inlet side of the engine 1000a, and provides compressed air and fuel to the engine 1000a. In particular, a central fuel injector 1030 injects vaporized fuel into a cavity defined by the inlet manifold lOOOd, which fuel mixes with the compressed air from the charger lOOOb via the intercooler 1000c.

[00134] Turbulence is added to the air-fuel mixture by a rotating element with vanes in the form of a s wirier 1035. The swirler 1035 is located within the inlet manifold lOOOd, and provides turbulence to the air-fuel mixture before it enters the drive shaft 1080.

[00135] The engine 1000a includes an ignition device 1.045 in the form of a direct fuel injector, a spark plug, a laser plug/laser igniter and/or a glow plug. The ignition device 1045 may assist in combustion of the air-fuel mixture, such as by providing a spark to ignite an air- petrol mixture, or to assist in starting the engine, such as by providing a heated element (glow plug) to a diesel engine.

[00136] The engine 1000a further includes an oil sump 1050, for storing oil fo lubricating the engine, including the pistons/cylinder walls, and various other moving parts as described in further detail below.

[00137] The internal combustion engine system 1 00 includes a starter generator 1055, which c mpris s a statof 1065 and a. rotor 1070, for assisting in starting the engine, and for generatin electricity for powering auxiliary devices while running. The starter generator 1055 also functions as a ^'flywheel, and thus can assist in preventing vibration in the engine.

[00138] Fig 1 la illustrates a perspective view of the cylinder block 1020, according to an embodiment of the present invention. Fig 1 lb illostrates an end view of the cylinder block 1020, Fig 1.1c illustrates a side view of the cylinder block 1020, and Figure 1 Id illustrates a perspective cutaway view of the cylinder block 1020.

[00139] Each cylinder .1 100 includes cylinder intake ports 1075, for providing a charged air- fuel mixture into the cylinder 1 100, exhaust ports 1085, for enabling combusted exhaust gases to escape from the cylinder 1100, and an ignition plug port 1300b, for providing an ignition plug, for example in the form of spark plug, in the case of a petrol engine, a glow plug, in the case of a diesel engine, and/or direct fuel injection to the cylinder 1100.

[00140] The intake ports 1075 are coupled to a central intake duct .1090, for providing the charged air and fuel mixture from the hollow drive shaft .1080. As the hollow drive shaft 1080 rotates, an outlet of the drive shaft aligns with a portion of the central intake duct 1090 that corresponds to one of the cylinders 1100. As such, the charged air and fuel mixture is selectively provided to cylinders 1 100.

[0014:1 ] The cylinder block 1020 further includes a cooling jacket 1030 for holding cooling fluid, for cooling of the cylinders 1100 during operation. The cooling jacket 1030 i completel sealed around the cylinder block 1020 so as to eliminate requirement for any gaskets, which reduces a risk of leaks,

[00142] Figure 12a illustrates an end cutaway view of the cylinde block 1020, cut along section B-B of Figure lie from an intake end of the engine 1000a, illustrating the intake ports 1300& Figure 12b illustrate a perspective cutaway view of the cylinder block 1020, cut alon section B-B of Figure l ie, from the intake end.

[00143] As discussed above, the central intake duct 1090 couples the compressed air-fuel mixture from the hollow drive shaft 1 80 to the cylinders 1100 by the cylinder intake ports 1075. The cylinder intake ports 1075 are evenly spaced around a wall of the cylinde 1100, and the cylinder intake ports 1075 of respective cylinders 1.100 are separated by intake channel walls 1095. The intake .channel walls 1095 enable the charge of compressed air-fuel mixture to be provided to each of the cylinders 1 1 0 individually, which eliminates the need for valves that open and close in each of the cylinders.

1 01441 Figure 12e illustrates an end cutaway view of the cylinder block 1020, cut along section C-C of Figure l ie from an exhaust; end of the engine 1000a, illustrating the exhaust ports 1300c. Figure 1.2d illustrates a perspective cutaway view of the cylinder block 1020, cut along section C-C, from the exhaust end,

[00145] The cylinder exhaust ports 1085 are evenly spaced around a wall of the cylinder 1100, and each cylinder is coupled to a respective exhaust port 1300c b the cylinder exhaust ports 1085.

[00146] Figure 13 is a perspective view of the internal combustion engine 1000a with the cylinder block 1020 removed, according to an embodiment of the present invention, The piston .1140 are connected to the reciprocating members 11.80 by connecting rods 1.120.

[00147] As the reciprocating member 1180 move back and forth along a linear path, the reciprocating motion of the reciprocating member 1180 turns the rotating member 1200 about its rotating axis.

[00148] Anti-rotation brackets 1105 prevent the reciprocating members 1 180 from rotating. In particular, the anti-rotation brackets 1105 are received in clianneis of the cylinder block 1020, to guide movement of the reciprocatin members 1 180 linearly.

[00149] Figure 14 is an exploded perspective view of a portion of the internal combustion engine 1 00a with the central cylinder block 1020 removed.

[00150] The hollow drive shaft 1080 includes drive teeth 1110 that engage with the rotating member 1200. In particular, rotation of the rotating members 1200 causes the hollow drive shaft 1080 to rotate.

[00151] The hollow drive shaft 1 80 is held in place by retention springs 1 1 15, which engage with the rotating members 1200, and prevent the drive shaft 1080 from disengaging from the rotating members 1200.

[00152] Figure 15 is an exploded perspective view of a portion of the drive shaft assembly 1.160, according to an embodiment of the present invention.

[00153] As discussed above, the drive shaft assembly 1 160 includes the reciprocatin member 1 180 and the rotatin member 1200, The drive shaft assembly 1160 further includes a counterweight 1 .125, for balancing the drive shaft assembly 1160. The counterweight 1 1.25 i coupled to the rotating member 1200 by a plurality of screws 1130, and thus also functions as a retention plate for the rotating member 1200. [00154] Figure 16a is a perspective view of the hollow drive shaft 1080, according to an embodiment of the present invention. Figure 3.6b is a end view of the hollow drive shaft 1080; and Figure 16c is a perspective cutaway view of the hollow drive shaft 1080,

[00155] The hollow drive shaft 1080 comprises an intake shaft 1 135, a central shaft 1 145 and an output shaft 11.50, Ends of the central shaft 1145 are received in fire intake, shaft 113.5 and the output shaft 1150 respectively.

[00156] An air intake 1155 is formed in a central portion of the intake shaft 1135, which extends partway through the central shaft 1145 to a rotary valve 1165, The rotary valve 1165 selectively provides compressed air-fuel mixture to the cylinders 1100, in cooperation with the intake channel walls 1095, according to a rotation of the hollow drive shaft 1080, In particular, when an output of the rotary valve 1165 is aligned with intake channel walls 1 95 of a particular cylinder 1100, compressed air- fuel mixture can be provided to that cylinder 1100.

[00157] Figure 1.7 is a perspective cutaway sectional view of the internal combustion engine 1000a wit the cylinder block 1020 removed, according to an embodiment of the present invention. Figure 17 illustrates the interaction between the hollow drive shaft 1080, and in. particular the rotary valve 1 165, with reference to the remaining component of the engine 1000a.

[00158] As discussed above, the engine 1000a includes variable cylinder compression. In particular, the drive shaft assemblies 1 160 can be axially translated such that a distance between opposing pistons 1140 is changed.

[00159] Figure 18a illustrates a sectional cutaway view of the engine 1000a i a low compression configuration and figure 18b illustrates a side cutaway view of the engine 3000a in a high compression configuration.

[00160] The engine 1000a includes hydraulic actuators 1170 comprising hydraulic pistons 1175 configured to translate the drive shaft, assemblies 1.160. In particular, the hydraulic piston 1175 forces the .drive shaft assemblies 1160 to move towards each other, thus forcing the pistons to move closer to each other, including in a maximum compression configuration.

[00161 ] As illustrated wit reference to Figure 18a, the hydraulic pistons 1 .175 are fully seated in the hydraulic- actuators- 1170. As a result, the pistons at the maximum compression configuration are separated by a relativel large gap, as illustrated by a first gap 1 185, thus resulting in a low compression configuration. [00162] As Illustrated with reference to Figure 18b, the hydraulic pistons 1175 are extended from the hydraulic actuators 1 170, forcing the drive shaft assemblies 1.160 to move towards each other. As a result, the pistons at the maximum compression configuration are separated by a relativel small gap, as illustrated by a second gap 1190, thus resulting in a high compression configuration.

[00163] According to alternative embodiments, a single hydraulic actuator may be used to force one of the drive shaft assemblie 1160 towards the other drive shaft assembly 1160. A such, compression of the engine can be changed while one of the driv shaft assemblies 1 160 may be statically configured.

[001.64] The skilled addressee will readily appreciate that variable cylinder compression can be achieved by means othe than hydraulic actuator 1170, such as through us of mechanical actuators or electro-mechanical actuators. Furthermore, the variable compression may, for example, be dynamic, i.e. change during operation of the engine 1000a, or preselected manually.

[00165] The engine 1000a may comprise a Homogeneous charge compressio ignition (HCCI) engine. In such case, the compression of the engine 1000a may be changed to adjust ignition timing of the engine. In particular, the compression of the engine 1000a can be set such that the vaporized air-fuel mixture is ignited at an optimum time in relatio to movement of the piston.

[00166] The internal combustion engine 1 00a may comprise a second actuator (not shown) configured to rock a face of a rotating member 1200 along a lateral axis. In particular, the second actuator may rock the face in concert with, or independently of the reciprocating member .1 180, in order to prevent port timing change of the engine 1000a caused by translation of the pistons 1.1.40,

[00167] As the hydraulic actuators 1170, forcing the drive shaft assemblies 3 160 to move towards each other, a location of the cylinder intake ports 1075 and the cylinder exhaust ports 1085 relative to the pistons will change. The second actuator may rock the face to compensate for such movement.

[00168] Furthermore, the internal combustion engine 1000a may comprise a third actuato configured t vary a position of the first rotating member 1200, in a rotational direction, relative to the second rotating member.

[0 1.69] According to alternative embodiments, the internal combustion engine 3000a may be configured to operate without a cooling jacket 1030. In particular, the pistons 1 140 may comprise carbon-carbon pistons, and the cylinder 1 100 may comprise an infused ceramic liner. These materials, in addition to being natural lubricants, are able to withstand higher cylinde temperatures, arid have lower thermal expansion than traditional aluminum pistons, for example.

[00170} In the present specification and claims (if any), the word 'comprising' and its derivatives including 'comprises' and 'comprise⁵ include each of the stated integers but does not exclude the inclusion of one or more further integers.

[00171] Reference throughout this specification to 'one embodiment' or 'an embodiment' means that a particular feature, structure, or characteristic described in connection with the embodiment is included, in at least one embodiment of the present invention. Thus, the appearance of the phrases in one embodiment' or n an embodiment' in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined i any suitable manner in one or more combinations.

[00172] In compliance with the statute, the invention has been described in language more o less specific to structural or methodical features. It is to be -understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is. therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (i any) appropriately interpreted by those skilled in the art.

Claims

1. An internal combustio engine including

a cylinder having one or more pistons for driving a drive shaft assembly, and a delivery system for delivering air to the cylinder through the drive shaft assembly.

2. The internal combustio engine of claim 1, wherein the drive shaft assembly includes a hollow drive shaft, for delivering air to the cylinder,

3. The internal combustion engine of claim 2, wherein the hollow drive shaft includes at least two parts removably connected to one another.

4. The intemal combustion engine of claim 2, wherein the hollow drive shaft is located along a central elongate axis of the- internal combustion engine.

5. The internal combustion engine of claim 1, wherein the one or more pistons are operatively adapted to drive the hollow shaft in cycles of rotation such that an outlet of the hollow drive shaft aligns with an inlet of the cylinder once per cycle o rotation: to allow air to pass from the hollow drive shaft into the cylinder.

6. The internal combustion engine of claim 1 , wherein the air delivery system delivers air to the cylinder from a charger, for charging the internal combustion engine.

7. The internal combustion engine of claim 1 , wherein the diive shaft assembly includes a reciprocating member for reciprocating along a predefined path, and a rotating member configured for engagement with the reciprocating member such tha reciprocating motion of the reciprocating member is transformed into rotation of the rotating member, wherein the rotation of the rotating member drives the hollow drive shaft.

8. The internal combustion engine of claim 7, further including one or more connecting rods connecting the one or more pistons with the reciprocating member, such that motion of the pistons is transferred to a reciprocating motion of the reciprocating member,

9. The internal combustion engine of claim 8, wherein each connecting rod has a spherical end portion configured for engagement with the reciprocating member, the spherical end portio being configured to facilitate relative motion between the reciprocating member and each connecting rod.

10. The internal combustion engine of claim 7, further including an operating chamber for housing at least a portion of the reciprocating member and the corresponding rotating member, wherein the operating chamber is configured to guide the reciprocating motion of the reciprocating member.

1 1 . The internal combustion engine of claim 1 , including a further: reciprocating member for reciprocating along a predefined path, and a further rotating member configured for engagement with the further reciprocating member such that reciprocating motion of th further reciprocating member is transformed into rotation of the further rotating member, wherein the reciprocating member and the corresponding rotating member are located adjacent an opposite end of the cylinder to the further reciprocating .member and the corresponding further rotating member,

12. The internal combustion engine of claim 1, including a plurality of cylinders arranged in parallel to one another around the hollow drive shaft.

13. The internal combustion engine of claim 1 , wherein each cylinder includes a parr of opposed pistons.

14. The- internal combustion engine of claim 1, further comprising an actuator, for translating the One or more pistons to change a compression ratio of the cylinder.

15. A method of operating an internal combustion engine, the method including

driving a drive shaft assembly using one or more pistons in a cylinder, and delivering air to the cylinder through the drive shaft assembly.

1.6. A charger for charging an internal combustion engine with compressed air, the charger including

a compressor fo providing compressed ai to the internal combustion engine, a first driver for driving the compressor, the first driver being configured to receive power from a drive shaft of the engine, and

a second driver for driving the compre sor, the second driver being configured to receive power from exhaust, of the engine,

the first driver and the second driver forming a single drive unit such that when the operation of the engine transitions from low revolutions per minute (RP ) to high RPM, load from the compressor shifts from the first driver to the second driver.

17. The charger of claim 16, wherein the first driver includes an input drive configured to engage with the drive shaft of the engine.

18. The charger of claim 16, wherein the second driver includes an exhaust impeller configured to be driven by the exhaust of the engine.

19. An engine assembly including the internal combustion engine of claim 1 and the charger of .claim 16.

20. A method for charging an internal combustion engine with compressed air, the method including

providing compressed air to the internal combustion engine,

hiving the compressor using a first driver, the first driver bein configured to receive power from a drive shaft of the engine, and

wherein the first driver and the second driver form a single drive unit such that when the operation of the engine transitions from low RPM to high RPM, load from the compressor shifts from the first driver to the second driver.