COMBUSTION ENGINE

TECHNICAL FIELD OF THE INVENTION:

The present invention relates to Internal Combustion engines.

BACKGROUND OF THE INVENTION:

Internal Combustion engines are very commonly being used in automobiles. They are popularly referred as IC engines. There are two types of IC engines that are very well accepted by the automobile industry namely reciprocating engines and rotary engines. Apart from these two, attempts made to use gas turbines in automobiles. Each of these types of engines has their own advantages and disadvantages. Automobile players judiciously select the type of the engine depending upon their needs and variants they offer to their clients. It is observed that the reciprocating engines have been widely used in the automobile industry over the rotary engine. There was a school of thoughts that would expect that the rise of rotary engines would address most of the problems with the reciprocating engines. The reciprocating engine includes a number of components that leads to vibrations and increases the weight of the engine. With the advent of the rotary engines the number of parts has been reduced but the inefficiency, higher emissions and engine durability issues have limited the adoption of the engine. There are problems relating to number of components, weight, and cost of reciprocating engines.

It is observed that there is uneven heat distribution in the rotor and enclosure of the rotary IC engines, namely Wankel rotary engine, which gives rise to problems making difficult to use as IC engines. As per the present state of art, in the rotary engines, the gas is moved from one place to another within the cylinder that affects adversely gas sealing in the engine. Therefore, there is a need of means that solves one or more problems as discussed above. There is also a need of means to increase power to weight ratio, reduce number of parts, reduce cost and increase the power of the IC engines.

SUMMARY OF THE INVENTION

The present invention provides a radial opposed piston reciprocating internal combustion engine. The engine includes a piston-cylinder assembly having a pair of piston assembly positioned in a cylinder. The piston assemblies are positioned facing opposite to one another in a cylinder. Each piston assembly includes a piston attached to a piston shaft. Outer surfaces of the pistons are configured to abut the inner periphery of the cylinder thereby defining a plurality of chambers. A pair of cylinder heads is connected to the cylinder. The piston shaft is passed through a hole configured on each cylinder head thereby enclosing the cylinder. The cylinder head has a plurality of slots configured thereon. A crankshaft assembly having a pair of crank is mounted on a crankshaft at predefined positions. The crankshaft passes through a hole configured in the cylinder heads. A pair of connecting arms is positioned on the piston shafts outside the cylinder.

A pair of connecting rods having a first end of each connecting rod is connected to the connecting arm and a second end of each connecting rod is coupled to the cranks of the crankshaft at other end thereof. The engine further includes a pair of valve timing mechanism. Each valve timing mechanism includes a plurality of valves and a bucket tappet slidably inserted into the slots configured on the cylinder head and a pair of gear assembly. Each gear assembly having a cam driver gear positioned on the crank shaft meshing with a cam driven gear positioned on the piston shaft or cylinder head. The bucket tappet passes motion and force from a cam attached onto cam driven gear to operate the valves.

BRIEF DESCRIPTION OF THU DRAWINGS

FIG. 1 is a perspective view of a radial opposed piston reciprocating IC engine in accordance with first embodiment of the present invention;

FIG. 2 is an exploded view of the IC engine of FIG. 1; FIG. 3 is a perspective view of the piston- cylinder assembly of FIG. 1;

FIG. 4 is a perspective view of a piston of the piston-cylinder assembly of FIG. 3; FIG. 5A-5C show perspective views of pistons and piston assembly with respect to alternative embodiment of the present invention;

FIG. 6 is an exploded view of a cylinder head assembly of the IC engine of FIG. i ;

FIG. 7 shows perspective view of crankshaft assembly of the IC engine of FIG. 1; FIG. 8 A shows a connecting arm of the IC engine of FIG. 1;

FIG. 8B shows a connecting rod of the IC engine of FIG. 1;

FIG. 8C shows a cam gear of the IC engine of FIG. 1;

FIG. 9 shows a valve timing mechanism of the IC engine of FIG. 2;

FIG. 10 shows combustion chambers of IC engine of FIG. 1;

FIG. 11 shows schematic diagrams of combustion chambers in accordance with working of IC engines of FIG. 1 ;

FIG. 12A shows perspective view of a radial opposed piston reciprocating IC engine without cover in accordance with second embodiment of the present invention

FIG. 12B shows exploded view of a radial opposed piston reciprocating IC engine of FIG. 12 A;

FIG. 13C shows perspective view of piston of IC engine of FIG. 12A;

FIG. 13A shows perspective view of cylinder head, of IC engine of FIG. 12A;

FIG. 13B shows sectional view of cylinder heads of the IC engine of FIG. 12A; FIG. 14 shows perspective view of a crankshaft assembly of the IC engines of FIG. 12 A;

FIG. 15 shows combustion chambers of IC engine of FIG. 12A;

FIG. 16A shows perspective view of a radial opposed piston reciprocating IC engine without cover in accordance with third embodiment of the present invention

FIG. 16B shows exploded view of a radial opposed piston reciprocating IC engine of FIG. 16 A;

FIG. 17 shows perspective view of a piston of the IC engine of FIG. 15 A; FIG. 18 shows perspective view of a half crankshaft of the IC engines of FIG. 15 A; and

FIG. 19 shows combustion chambers of IC engine of FIG. 15 A.

PET ATT, ED DESCRIPTION OF THE INVENTION

Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention.

References in the specification to“one embodiment” or“an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase“in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers in brackets indicate corresponding parts in the various figures.

Referring to FIGS. 1-9, a radial opposed piston reciprocating internal combustion engine (100) (hereinafter“the engine (100)”) in accordance with first embodiment of the present invention is shown. The engine (100) includes a piston-cylinder assembly (120), a pair of cylinder head assembly (134), a crankshaft assembly (140), a pair of connecting arms (150), at least one pair of connecting rods (160), a valve timing mechanism (170) having a pair of gear (180). The piston cylinder assembly (120) is enclosed in the pair of cylinder head assembly (134). The cylinder head assembly (134) and piston-cylinder assembly (120) include the crankshaft (140) supported therein. A pair of piston assembly (122) of the piston-cylinder assembly (120) includes a pair of connecting arms (150) fixed thereon. The connecting arms (150) have the connecting rods (160) attached at the end portions thereof by using a connecting means such as a pin. The crankshaft assembly (140) and the cylinder head assembly (134) support the valve timing mechanism (170). Each piston assembly (122) includes a piston disk (122A), at least one piston (128) and a piston shaft (122B). The cam driven gear (184) of the valve timing mechanism (170) is mounted on the cylinder head assembly (134) and rotates freely thereon and cam driver gear (181) is rigidly mounted on the crankshaft assembly (140). In alternative embodiment, the cam driven gear (184) of the valve timing mechanism (170) is mounted on the piston shaft (122B).

Referring to FIG. 3 and 4, the piston-cylinder assembly (120) in accordance with an embodiment of the present invention is shown. The piston- cylinder assembly (120) includes a pair of piston assembly (122), a cylinder (124) and a predefined number of spark plugs (126). In an embodiment, for diesel engines, spark plugs can be replaced by diesel injectors. The piston disk (122A) has a predefined shape and has at least one piston integrated thereto. In an embodiment as shown in Figures 3 and 4, two pistons (128) are integrated on the periphery of the piston disk (122A) having an angular distance of 180° there between. It is understood here that the shape of pistons (128) may be designed according to desired combustion efficiency and performance of the combustion chamber (130). The pistons have rectangular, circular, square or oval cross- section. A width of the pistons (128) is double as that of the thickness of the piston disk (122A). However, it is understood here that the shape, number, angle and configuration of the pistons (128) may vary in alternative embodiments of the present invention based on the type of stroke required. The piston disk (122A) includes the shaft (122B) attached at a centre thereof. The piston shaft (122B) includes a plurality of splines (127) configured at a predefined location thereon.

Referring to FIG. 5, a piston assembly (520) in accordance with alternative embodiment of the present invention is shown. In this one embodiment, the piston assembly (520) includes two piston assemblies (522, 523). A first piston assembly (522) includes a first piston disk (522A) having pistons (528A) connected to a first piston shaft (522B) and a second piston assembly (523) includes a second piston disk (523A) having pistons (528B) connected to a second piston shaft (523B). The first piston disk (522A) and the first piston shaft (522B) have a hollow bore configured therethrough having diameter matches with the diameter of the second piston shaft (523B). The second piston shaft (523B) is inserted into the bore of the first piston assembly (522) thereby forming the piston assembly (520). The second piston shaft (523B) rotates freely in the first piston shaft (522B) in opposite direction to each other. It is understood here that angle between the pistons (528A, 528B) are defined as per the requirement of the shape and angle between the chambers to be formed by the piston assembly (520) with the cylinder (124).

Referring to FIGS. 3 and 6, the pair of pistons (122) is connected to the cylinder (124) having a predefined shape. The periphery of the cylinder (124) includes a plurality of slots (121) of predefined shapes configured thereon. The slots (121) provide passages for cooling water. It is to be noted here that width of the cylinder (124) matches with the width of the pistons (128) of the piston disk (122A). However, it is understood here that the shape of the cylinder (124) and configuration of the slots (121) thereon may vary in alternative embodiment of the present invention.

Referring to FIGS. 3-6, the piston disk (122 A) and the pistons (122) are received in the cylinder (124) and fixed at inner periphery thereof by using the connecting means. In an embodiment, the piston disk (122A) of one piston is slidably contacting to the piston disk (122A) of another. The outer surfaces of the pistons (128) abut the inner periphery of the cylinder (124) thereby defining chambers (130). In an embodiment, as the piston disk (122A) of each piston assembly (122) has two pistons (128), the pair of piston assembly (122) and cylinder (124) defines four chambers (130) at the inner periphery of the cylinder (124). However, it is understood here that the number of chambers (130) may vary in alternative embodiments of the present invention. It is to be noted here that both the pistons (122) rotate back and forth, that is, oscillate around the shaft’s (122B) common axis within a predefined angle opposite to each other. The angular distance between the piston assemblies (122) may vary between 1° and 90° depending on the crank position. However, the angle of rotation for each piston assembly (122) may be determined by the length of the connecting arm (150), the length of the connecting rod (160), the crank radius and the distance between the crankshaft (140) and piston shaft (122B). The outer periphery of the cylinder (124) has a predefined number of slots (125) configured thereon. The holes receive spark plugs (126) or injectors (Not Shown) therein.

Referring to FIGS. 6, a cylinder head assembly (134) in accordance with an embodiment of the present invention is shown. The cylinder head assembly (134) includes a disc (136) having a cylinder head (135) integrated at one surface thereof. The shape of cylinder head (135) exactly matches with the shape of the cylinder (124). The cylinder head (135) includes a plurality of slots (137) configured on the surface periphery thereof. The slots (121) of the cylinder (124) match with the slots (137) of the cylinder heads (135). The slots (121, 137) act as cooling passages communicating with internal passages (Not Shown) within the cylinder head (135). The cylinder heads (135) house the intake and exhaust valves that facilitates air intake and exhaust into and from the cylinder (124). Valves (172) are slidably inserted into the cylinder head (135), valve lock (not shown here) and valve spring (174) keeps the valves (172) in close position. Bucket tappet (176) slidably inserted into the cylinder head (135) that passes the motion and force from the cam (173) attached onto cam driven gear (184) to open and close the valves (172). In an embodiment, the pair of cylinder head assembly (134) are fixed to the cylinder (124) on either side thereof such that centres (138) of the cylinder heads (135) receive shafts (122B) of the pistons. The pair of cylinder head assembly (134) includes an intake cylinder head assembly (134) and an exhaust cylinder head assembly (134). The cylinder (124) is sandwiched or enclosed between the cylinder head assembly (134). The cylinder head assemblies (134) are connected to the cylinder (124) by using the connecting means. The splined portions (127) of the shafts (122B) of the piston are passed through the centres (138) of the cylinder heads assembly (134).

Referring to FIG.7, a crankshaft assembly (140) in configuration with the internal combustion engine (100) in accordance with an embodiment of the present invention is shown. The engine (100) includes at least one crankshaft assembly. In an embodiment, the engine (100) as shown in Figures 1-7 includes a crankshaft assembly (140) is positioned in the holes (139) configured on the cylinder head assembly (134) at predefined positions. Each crankshaft assembly (140) includes a crank (142) mounted on a crankshaft (144). In an embodiment, the crankshaft assembly (140) shown in Figure 7 includes the two cranks (142) rigidly fixed at the ends of the crankshaft (144) facing opposite to each other. The crankshaft assembly (140) is positioned in the engine (100) such that each crankshaft (144) passes by the cylinder (124) aligned with a hole (139) of the cylinder head assembly (134). The crank shaft assembly (140) includes two piece of crankshaft (144) rigidly fixed in the middle by crankshaft coupling (143). However, the crankshaft assembly (140) may be made in single piece as crankshaft of the conventional multi -cylinder engines. In this embodiment, the crankshaft assembly (140) is made in two pieces to ease the assembly and other considerations. It is to be noted here that if the crankshaft (140) is made in single piece, then the cylinder (124), cam driver gear (181) and cylinder head assembly (134) design needs to be changed accordingly.

Again referring to FIGS. 1-4, and 8 A, the splined portions (127) of the piston shafts (122B) receive a pair of connecting arms (150) thereon. The connecting arms (150) include a pair of arms (152) of a predefined shape. The connecting arm (150) have a splined hub (154) configured at a centre thereof that connects the connecting arm (150) in parallel configuration with each other. The splined hub (154) is rigidly fixed with the splined portion (127) of the piston shaft (122). Each arm includes one or more holes (156) configured at end portions thereof. The connecting arms (150) oscillate with the pistons (122) in an angular motion. According to the invention, one of the connecting arms (150) oscillates in opposite direction to that of the other.

Each connecting arm (150) includes a connecting rod (160) connected thereto at a predefined angle. However, the angle varies according to the crank position. In an embodiment, the connecting rod (160) is of capsule shape having a pair of holes configured at the end portions thereof. One hole of the connecting rod (160) is aligned with one end of the connecting arm (150) and fixed thereto by using a connecting means such as a connecting arm pin (not shown). In an embodiment, each connecting arm (150) includes a connecting rod (160) connected at the holes configured thereon. Other ends of the connecting rods (160) are fixed to the cranks (142) by a crank pin of the crankshaft (144). However, it is understood here that the two crankshafts (140) may be positioned having 180° opposite to each other therein the alternative embodiments of the present invention. In such as case there would be a connecting arm with a hole at other end also and receives another connecting rod. The other end of the second connecting rod connects to the other crankshaft.

Referring to FIG. 9, a valve timing mechanism (170) in accordance with an embodiment of the present invention is shown. In an embodiment, the valve timing mechanism (170) includes a plurality of gears of different predefined diameters working in configuration with one another. Valve timing mechanism (170) consists of valves (172), valve spring (174), bucket tappet (176) and gear assembly (180). The gear assembly (180) includes a cam driver gear (181) and a cam driven gear (184). The motion of the crankshaft (140) is transferred by the cam driver gear (181) to the cam driven gear (184). The cam driven gear (184) includes a radial cam (173) is configured to operate the intake and exhaust valve opening and closing timing based on the cam profile and angular position of the crankshaft (140). The valves (172) are positioned in valve seats (175) in the cylinder head (135). The valves (172) include intake and exhaust valves. The valves (172) open and close the intake and exhaust passageway for air to intake in the combustion chamber (130) during intake stroke and to expel the burned (exhaust) gases out of combustion chamber (130) after the completion of expansion stroke.

In accordance with this one embodiment, as the cam (173) comes in contact with bucket tappet (176), the cam pushes the bucket tappet (176) in the cylinder head (135), that in turn pushes the valve (172) and causes the air intake or exhaust passage open. The bucket tappet (176) receives force from cam and moves along valve’s axis according to the cam profile. This action pushes valves (172) to open it against the spring (174) force. The cam profile may be designed in such a way that the same may be made to slide from radially inward to outward on cam driven gear (184) in order to change the valve opening/closing timings. In accordance with this one embodiment, there are two valve timing assemblies (170) per engine, one each for intake and exhaust valves. However, it is understood here that the number of valve timing assembly may vary or the valve timing assembly may be replaced by a suitable mechanism such as chain driven cam wheel, electromagnetic based valve actuator, hydraulic pressure driven valve actuation, rotary valve actuation mechanism in alternative embodiments of the present invention. In accordance with an embodiment, the ratio between the cam driver gear (181) and the cam driven gear (184) is 2: 1. Accordingly, for every rotation of the cam driven gear (184) the cam driver gear (181) and the crankshaft (144) rotate twice.

Referring to FIG.10, as the engine (100) runs, the pistons (122) form four chambers (130). As the expansion/power stroke in one of the chambers exerts pressure on the pistons (128), the pistons (128) move away from each other. That produces torque on the piston shaft (122B) and hence on to the connecting arms (150) that translated in to the torque on crankshafts (144) via connecting rod (160).

In accordance with the present invention, the components outside of the cylinder heads (135), such as piston shafts (122B), connecting arms (150), connecting rods (160), cranks (142), valves (172), valve timing mechanism (170) etc., can be enclosed by covers (190). The covers can be designed in such a way that the components get enclosed and also provide structural rigidity to the entire engine. The cover may contain oil for lubrication and also provide space to mount other accessories such as alternator, oil pump, water pump etc.

Referring to FIG. 11, the angular motion of the piston assembly (122) is determined by the crank radius, length of the connecting rod (160) the length the connecting arm (150) and the distance between crankshaft (140) and piston shaft (122B). One end of the piston shaft (122B) is supported by the cylinder head (135) and the other end of the shaft (122B) is supported by the engine enclosure (not shown) with the bearings to allow free rotation of the piston assembly (122) around the shaft axis.

Referring to FIG. 1-11, in operation, as the pistons (122) oscillate; the volume in two out of four chambers (130) reduces while the volume in other two chambers increases. Thus, out of the two reducing volume chambers, one performs the compression stroke and the other performs the exhaust stroke. The rest two increasing volume chambers (130) perform either expansion or the suction stroke. The role of the chambers (130) change as the pistons reverses the direction.

The chambers experience the strokes in a predefined sequence as: intake, compression, expansion and exhaust. With reference to this one embodiment, if four chambers (130) are counted in a clockwise direction, then the 1st chamber experiences the intake stroke, the 2nd chamber experiences the exhaust stroke, the 3rd chamber experiences the expansion stroke and the 4th chamber experiences the compression stroke. As these stokes end, the 2nd chamber, that had experienced the exhaust stroke, experiences the intake stroke. The 3rd chamber experiences the exhaust stroke. The 4 ^th chamber experiences the expansion stroke and the 1st chamber experiences the compression stroke. After each stroke, the chambers (130) keep experiencing sequential change of strokes as shown in FIG. 10 and keep generating torque.

As the engine (100) runs all the 4-strokes of the conventional 4-stroke 4- cylinder engine occurs simultaneously. However, the engine behaves as opposed piston 4-stroke engine because the pressure generated by combustion of fuel pushes both the pistons (122) away from each other simultaneously. Thus, both cranks (142) generate the power during each 180 degree of rotation.

Referring to FIGS. 12A-15, a radial opposed piston reciprocating internal combustion engine (200) (hereinafter“the engine (200)”) in accordance with second embodiment of the present invention is shown. In this one embodiment, the engine (200) acts as a four chamber-two stroke engine (200). The basic construction of the engine (200) is similar to engine (100) with several difference such the engine (200) does not have valve timing mechanism. Further, there are intake and exhaust ports (204,206) in the engine (200) that open and close by the piston movement.

The engine (200) includes a pair of cylinder heads (235), a crankshaft (240), at least one pair of connecting arms (250), at least one pair of connecting rods (260). The piston cylinder assembly is enclosed in the pair of cylinder heads (235). The cylinder heads (235) and piston-cylinder assembly include the crankshaft (240) supported therein. A pair of piston assembly (222) of the piston- cylinder assembly includes a pair of connecting arms (250) fixed thereon. Each connecting arm (250) has the connecting rod (260) attached at the end portions thereof by using a connecting means such as a pin.

Each piston assembly (222) includes a piston disk (222A), at least one piston (228) and a piston shaft (222B). In an embodiment, two pistons (228) are integrated on the periphery of the piston disk (222A) having an angular distance of 180° there between. The pistons (228) have venture shape having concave portion configured at one side face thereof. However, it is understood here that shape and configuration of the piston (228) may vary in alternative embodiments of the present invention. The pistons (228) may include rectangular, circular, square or oval cross-section. In an embodiment, as the piston disk (222A) of each piston assembly (222) has two pistons (228), the pair of piston assembly (222) and cylinder (224) defines four chambers (230) at the inner periphery of the cylinder

(224). The outer periphery of the cylinder (224) has a predefined number of holes

(225) configured thereon. The outer periphery of the cylinder (224) also includes ports (204, 206) configured thereon that act as an intake and exhaust (204, 206) ports respectively. The holes (225) receive spark plugs (226) therein. Injectors can be used in diesel engine or direct injection petrol engine. All the elements of the engine (200) is enclosed by a cover (290)

Referring to FIG. 12A-15, in operation, in this embodiment, the air is drawn into and expelled from combustion chamber through intake and exhaust ports respectively. The opening and closing of intake and exhaust ports at a predefined crank angle is controlled by the piston (228) movement. Since, both the intake and exhaust happens through intake and exhaust ports (204, 206) in a one stroke and compression in another stroke, the engine (200) is called 2-stroke engine. At the end of the compression stroke a spark is generated or the diesel fuel is injected that ignites the fuel air mixture and pressure on the pistons (228) is created such that the pistons (228) move away from each other thereby rotating the crankshaft (240). The crankshafts (240) having cranks (242) positioned on the shafts (244) are joined together thereby forming a crank coupling (243)

In accordance with this one embodiment, as the pistons (228) move away from each other in expansion stroke from two of the chambers (230), the other two chambers (230) would have completed the exhaust and intake from previous stroke. Now these two chambers (230) perform the compression stroke as the ports get closes by the piston motion. The first two chambers (230) experience expansion stroke and as the pistons (228) movement opens exhaust and intake ports expel the burned gases and take in fresh charge at the same time. The cycles continue and the pairs of chamber (1 & 3, 2 & 4) go through cycle of intake- expansion-exhaust and compression strokes. Similar to the earlier 4-stroke design, this 2-stroke engine has 4-chambers and the pistons (228) facing two opposite chambers (230) simultaneously generates power stroke every 180 degree rotation of the crankshaft (240).

Referring to FIGS. 16A-19, a radial opposed piston reciprocating internal combustion engine (300) (hereinafter“the engine (300)”) in accordance with third embodiment of the present invention is shown. In this one embodiment, the engine (300) acts as a two chamber-two stroke engine (300). The engine (300) includes a piston- cylinder assembly (320), a pair of cylinder heads (335), a crankshaft (340), a pair of connecting arms (350), at least one pair of connecting rods (360), The piston cylinder assembly (320) is enclosed in the pair of cylinder heads (335). The cylinder heads (335) and piston-cylinder assembly (320) include the crankshaft (340) supported therein. A pair of piston assembly (322) of the piston-cylinder assembly (320) includes a pair of connecting arms (350) fixed thereon. Each connecting arm (350) has the connecting rod (360) attached at the end portion thereof by using a connecting means such as a pin. Each piston assembly (322) includes a piston disk (322A), at least one piston (328) and a piston shaft (322B). In an embodiment, two pistons (328) are integrated on the periphery of the piston disk (322A) having an angular distance of 180° there between. The pistons (328) have venture shape. However, it is understood here that the shape and angular configuration of the pistons (328) may vary in alternative embodiments of the present invention. The pistons (328) may include rectangular, circular, square or oval cross-section. In an embodiment, as the piston disk (322A) of each piston assembly (322) has two pistons (328), the pair of piston assembly (322) and cylinder (324) defines two chambers (330) at the inner side of the cylinder (324). The outer periphery of the cylinder (324) has a predefined number of holes (325) configured thereon. The holes (325) receive spark plugs (326) therein. The outer periphery of cylinder (324) also includes ports (304, 306) configured thereon that act as intake and exhaust ports (304, 306) respectively. In case of diesel engine the spark plugs are replaced by injectors as in previous embodiments. All the elements of the engine (300) are enclosed in a cover (390).

In accordance with this one embodiment, in the engine (300) in an exhaust valve may be added and the intake may carried out by intake port. It is to be noted here, addition of the exhaust valve provides some flexibility that can be utilized to enhance the engine performance, efficiency and emissions as the exhaust valve can be controlled to a desired timing.

Referring to FIGS. 16A-19, in operation, in engine (300) only 2-chambers perform the same task the other two chambers do not take part in any strokes. In this one embodiment, the engines air is taken in from intake port (304) while exhaust is expelled from the exhaust port (306). This happens when the pistons (328) move away from each other in expansion stroke and uncovers the intake port and exhaust ports at a predefine crank angle. In accordance with this one embodiment, the intake port (304) and exhaust ports (306) open and close simply by piston (328) movement. Intake, exhaust, expansion and compression happen in two chambers (330) only. This allows other two chambers (330) to be free of any action that facilitate bringing the crankshaft (340) within the cylinder (324) circumference while in the engines (100) or (200) described in the first and second embodiments respectively, the crankshaft (340) is outside the cylinder (324).

The IC engine (100, 200, 300) of the present invention is compatible for fuels such as Petrol, Natural gas, LPG, diesel, bio-diesel, landfill gas and the like.

The engine elimination of piston side thrust hence reduction in friction. The engine (100, 200, 300) of the present invention generates double the power strokes compared to conventional 4-stroke, 4-cylinder engine. The IC engine (100, 200, 300) increases power to weight ratio and includes less number of parts thereby reducing the complexity of the system. The IC engines (100, 200, 300) reduces cost due to less number of parts and smaller size.

The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.