Connecting rod and crankshaft arrangement for internal combustion engine

Abstract

A Reciprocating Internal Combustion Engine (RICE) comprises a cylinder block defining at least one cylinder having a longitudinal cylinder axis, which represents the piston axis line of stroke, a piston configured to reciprocate within the said cylinder along the axis line of stroke between the Top and Bottom Dead Centers, a connecting rod and a crankshaft assembly. The connecting rod and the crankshaft assembly comprise, a connecting rod, a crankshaft wherein the crankshaft comprises a crankpin, the crankpin comprising an outer mating surface with the inner surface of the con rod bearing shell. Moreover, the said crankpin outer surface has a circumferential geometrical recess with a specified depth of cut; and an efficiency-boosting assembly fitted to the said recess thereby substantially enhancing the efficiency of the engine.

Description

CONNECTIG ROD AND CRANKSHAFT ARRANGEMENT FOR INTERNAL COMBUSTION ENGINEField of the Invention

[0001] The present invention relates to methods and apparatus and to methods and apparatus which provide an efficiency-boosting arrangement adapted to improve force transmission between connecting rods and crankpins during the expansion stroke of a reciprocating internal combustion engine (RICE) to, significantly, enhance the engine efficiency.Background of the Invention

[0002] The present invention relates to efficiency-boosting in reciprocating internal combustion engines (RICE) and is more particularly directed to improving gas force transmission between a connecting rod big end assembly and crankpin of a (RICE) thereby, substantially, enhancing the engine efficiency.

[0003] Reciprocating internal combustion engines have long powered various applications, but they face persistent challenges in efficiency and emissions. While advancements like turbocharging and variable valve timing have made strides, opportunities remain for further enhancement.

[0004] The conventional engine design's complex interactions lead to energy losses due to friction, heat, and inefficient combustion. These inefficiencies hinder progress toward cleaner, more sustainable engine technology.

[0005] In response to these challenges, the present invention introduces an innovative Efficiency-Boosting Arrangement for Reciprocating Internal Combustion Engines. This arrangement addresses efficiency and emissions issues through a unique combination of components and mechanisms, ushering in a new era of engine performance and environmental responsibility.Description of Prior Art

[0006] In conventional Reciprocating Internal Combustion Engines (RICE), pistons are coupled to a crankshaft by connecting rods to translate the reciprocating motion of pistons to the rotary motion of the crankshaft. The engine power is delivered when the explosions inside the combustion chambers take place during the expansion stroke where forces aretransmitted from the pistons to the connecting rods to the crankshaft to the driveline. Unfortunately, at the expansion stroke Top Dead Centre (TDC) position of a piston, the force applied by the piston is collinear with the axes of the crankpin and the crankshaft simultaneously. This means that no output torque or turning force at this instant i.e. , no energy is delivered by the crankshaft to the driveline thereby efficiency of the engine is, substantially, reduced causing more harmful emissions which represents a challenging problem during the last century.

[0007] To alleviate this problem, prior art engines incorporate various efficiency enhancement designs and control devices. Normally, these devices are related to improving combustion performance and / or power enhancement. Among these devices are the following:1. Introducing a modification in the combustion system and its arrangement,2. Variable Valve Timing and Lift: certain valve timing produces better fuel efficiency, and different timing produces more power,3. Petrol Direct Injection where an accurate amount of petrol is injected directly into each of the already air-filled cylinders which improves fuel and reduces emission level at low load,4. Variable Displacement / Cylinder Deactivation, such a mechanism controls the number of cylinders that run on. Fuel flow to the inactive cylinders is cut and the valves are deactivated. With fewer cylinders to fill, fuel economy improves,5. Introducing a better cooling system and making use of the hot exhaust gases,6. Introducing a better lubricating system for less friction losses,7. Replacing the conventional Slider Crank Mechanism (SCM) with another one that produces more power,8. Carrying out major modifications and changes to the conventional SCM to increase the power.9. Carrying out very slight modification changes to the conventional SCM to increase the power without adding additional fuel, i.e., to enhance efficiency.

[0008] However, most of the efficiency-boosting devices of the prior art suffer from the drawback that they cannot be simply incorporated into conventional internal combustion engine designs, are expensive to manufacture, complicated, and have slight efficiencyenhancement contribution. Therefore, there is a real need for an efficiency boosting device for a reciprocating internal combustion engine (RICE) to alleviate all of the drawbacks of the prior art in a simple, efficient and inexpensive manner.

[0009] Patent Number: GB2583956B (UK Patent Application No: GB 1906890.7), represents an example of carrying out very slight modification changes to the conventional RICE, mentioned in item 9 above, presented three embodiments to solve the low- efficiency bottleneck problem; the Con Rod big end housing, the crankpin outer surface and the crank arm (web). In all of them, the Dynamic Force-Split Concept (DFSC) wherein a half elastic pad was employed in the assembly. On the other hand, application number EP 19186064.2 represents another example of solving the low-efficiency problem by carrying out slight modification to the con rod big end, where a Symmetric Elastic Pad SEP is employed. In the SEP a Dynamic Force-Lag Concept (DFLC) is used to increase the efficiency of the engine.

[0010] In the present invention, new developments and findings have been made since the UK and EP applications were filed in 2019. In the present invention, however, the Dynamic Force-Split Concept (DFSC) and the Dynamic Force-Lag Concept (DFLC) are combined in the form of an efficiency-boosting arrangement in a simple, robust, inexpensive, smart manner and produce better resultsSummary of the Invention

[0011] Aspects of the present invention are set out in the independent claims. Optional features giving examples of the disclosure are set out in the dependent claims. The present disclosure provides an efficiency-boosting arrangement adapted to improve force transmission between connecting rods and crankpins during the expansion stroke of a reciprocating internal combustion engine (RICE) to, significantly, enhance the engine efficiency.

[0012] A Reciprocating Internal Combustion Engine (RICE) as per the present disclosure may comprise at least one reciprocating piston and a crankshaft having at least one crankpin journal, both the said piston and the said crankpin journal are linked by a connecting rod. In some examples, the connecting rod has a split big end adapted for holding the connecting rod journal of the crankpin and connecting rod bearing shell, and a small end defining a pin opening provided to receive a piston pin. In some examples,the connecting rod's big end housing circumscribes the crankpin journal. The crankpin outer surface has a geometrical recess having a specified uniform depth of cut in the direction of the circumference of the outer mating surface, the said geometrical recess depth is at most equal to the con rod bearing shell thickness, wherein the said recess cut is made along the entire length of the said crankpin and parallel to its axis. For example, the force control member may have a thickness equal to the depth of the circumferential geometrical recess. Moreover, the said geometrical recess may have a circumferential arc length, which specifies its extension angle wherein at the TDC the said recess extension angle is bisected by the axis line of stroke, which intersects the axes of the said crankpin and the said crankshaft simultaneously. Furthermore, in some examples, the said extension angle of the said geometrical recess is equal to the conventional crankpin-con rod force distribution extension angle, which is bisected by the axis line of stroke at the TDC position of the expansion stroke. An efficiency-boosting assembly is fitted to the said recess thereby substantially enhancing the efficiency of the engine. The said efficiencyboosting assembly comprises a force control member mounted in and fixed to the said geometrical recess. As will be apparent, the terms force control member and the efficiency-boosting assembly may be used interchangeably herein. The force control member, may be made of durable elastic metal. For example, the term durable elastic metal may refer to a metal having less stiffness than the stiffness of said crankpin material. Arrangements wherein the force control member comprises a metal having less stiffness than the stiffness of the crankpin material (e.g. a durable elastic metal), the force control member may tend to influence the rate of force transmission to the crankshaft. Moreover, the said force control member has dimensions and shape to fit properly in the said geometrical recess (e.g. the radial depth of the force control member is the same as the depth of the geometrical recess and / or the circumferential and / or axial spatial extent of the force control member is the same or substantially the same as that of the geometrical recess, for example, the force control member may sit within the geometrical recess (e.g. to provide a transition fit or an interference fit between the force control member and the geometrical recess) ; it also has a uniform thickness in the direction of the circumference of the outer mating surface, which is at most equal to the thickness of said bearing shell (e.g. in such examples, a top surface of the force control member may sit flush within the geometrical recess, for example, so that there is no radial difference between the height of the force control member and a surface surrounding the geometrical recess). In examples, the said force control member is arranged in the said geometrical recess defined in the said crankpin, wherein the entire outside surface of the crankpin togetherwith the outside surface of the said force control member of the efficiency-boosting assembly has a circular cross-section that cooperates with the said bearing shell. In such examples, similar to the said geometrical recess, the said force control member of the efficiency-boosting assembly has an angle equal to the conventional crankpin-con rod force distribution extension angle, which is bisected by the axis line of stroke at the TDC position of the expansion stroke.

[0013] Therefore, the present disclosure provides a simple, inexpensive, practical, durable and smart efficiency-boosting arrangement for modifying and influencing the rate of force transmission between the connecting rods and the crankpins to the crankshaft for increasing the engine output power without additional fuel consumption, thereby substantially boosting the engine efficiency.Brief description of the drawings.

[0014] The preferred embodiments of the present invention will now be described with the reference to accompanying drawings.FIG. 1 is a partially exploded view of an internal combustion engine with its efficiencyboosting arrangement according to the first exemplary embodiment of the present invention.FIG. 2 is a perspective view of an internal combustion engine crankshaft's main components together with the efficiency-boosting arrangement as per the first exemplary embodiment of the present invention.FIG. 3 is an exploded view of the connecting rod and crankpin incorporating the efficiencyboosting arrangement main components as per the first exemplary embodiment of the present invention.FIG. 4 a cross-sectional view of the internal combustion engine of the present invention when, a) one of the pistons is at TDC of the expansion stroke showing the efficiency-boosting arrangement effect on the forces’ distributions wherein the extension angle bisector coincides with the axis line of stroke, b) the force control member modelling at the TDC of the expansion stroke, andc) when the crankshaft keeps rotating after passing the axis line of stroke while the extension angle bisector is still within the range of the extension angle of the conventional engine as per the first exemplary embodiment of the present invention.FIG 5. a simulation of gas / forces loading and performance test comparisons between single-cylinder conventional and modified engines, a) Cylinder gas pressure versus volume, b) Contact forces between the con rod and crankpin for conventional and modified engines, c) The produced torque of the conventional and modified engines, and d) the characteristic performance curves for the conventional and the modified engines.FIG. 6 a partially exploded view of: a) A V-type internal combustion engine with its efficiency-boosting arrangement and b) Efficiency boosting arrangement main components, according to the second exemplary embodiment of the present inventionFIG. 7 a cross and longitudinal sectional views of the internal combustion engine according to the second exemplary embodiment of the present invention showing: a) The forces’ distributions and b) A longitudinal cross section for the crankpin and the efficiency-boosting arrangement.Figure 8A illustrates an exploded view of a Reciprocating Internal Combustion Engine (abbreviated to RICE) provided by the present disclosure.Figure 8B illustrates an exploded side view of a connecting rod and crankpin of a connecting rod and crankpin assembly of the present disclosure.Detailed description

[0015] In this detailed description, the preferred embodiments of the present invention will be described in the light of the accompanying drawings through examples that will not have any limiting effect on a deep understanding of the invention subject. FIG. 1-7 of the drawings illustrate the exemplary embodiments of the Reciprocating Internal Combustion Engine (RICE), 10, provided with an “efficiency-boosting arrangement” 30 of the present invention.

[0016] With reference to FIG. 1-5 wherein the RICE 10 includes a cylinder block 20 having a plurality of piston receiving bores 21 for receiving a piston 31 , which reciprocates therein along the axis line of stroke 211. The RICE 10 further includes a crankshaft assembly 33 having a plurality of crankpins 333 which are rotatably mounted by bearing shells 322 & 323 to big ends of connecting rods 32. It will be appreciated by those skilled in the art that while only four crankpins 333, four cylinders 21 and four pistons 31 are illustrated in FIG. 1 , the RICE 10 may include any appropriate number of cylinders, such as one, two, three, etc., and may be of in-line engine as well as V-engine or opposed cylinder or opposed piston engine configuration.

[0017] The crankshaft assembly 33 converts the reciprocating motion of pistons 31 into rotary motion in a manner well-known in the mechanical engineering arts.

[0018] As illustrated in FIG. 1 , the connecting rod 32 as per the present invention, has a big end housing adapted for receiving the crankpin 333 of the crankshaft assembly 33 and the connecting rod bearing shell 322 & 323. The outer surface of the said connecting rod bearing shell 322 & 323 has an interference fit with the inner surface of the connecting rod big end housing 3221 & 3231 , wherein a lubricating oil film exists in the clearance between the crankpin 333 and the con rod bearing shell 322 & 323 allowing for force transmission between the connecting rod 32 and the crankpin 333.

[0019] To effectively improve the transmission of energy from the connecting rod 32 to the crankshaft 331 , an “efficiency-boosting arrangement” 30 is mounted between the crankpin 333 and the connecting rod bearing shell 322 & 323.

[0020] Consider a conventional RICE that has a typical crankpin-con rod force distribution extension angle 3240 at the commencement of the expansion stroke, wherein the extension angle 3240 is bisected by the axis line of stroke 211 at the TDC position of the expansion stroke. The said efficiency-boosting arrangement 30 per the first exemplary embodiment of the present invention comprises a recess 3331 which is cut geometrically in the crankpin 333 outer surface and a force control member 334. The geometrical recess 3331 has a circumferential extension angle 33313 which is designed to be equal to the conventional RICE typical crankpin-con rod force distribution extension angle 3240 which is bisected by the axis line of stroke 211 at the TDC. Moreover, recess 3331 has a length33312, which is parallel to the crankpin axis 3330 and is equal to the crankpin axial length 33312. The geometrical recess 3331 , also, has a circumferential uniform cut depth 33311 , which at most equals the con rod bearing shell thickness 3320. The shortest line 3314 that intersects the crankshaft axis 3310 and the crankpin axis 3330 at the TDC of the expansion stroke and coincides with the axis line of stroke 211 , representing the extension angle bisector 3314 of the recess 3331 . The recess 3331 is adapted to receiving the said force control member 334 which fits in and is fixed to the said recess 3331 for, significantly, enhancing the transmission of forces from the connecting rod 32 to the crankshaft 331. The force control member 334 is made of reliable and durable elastic metal having a stiffness, which is less than the stiffness of the crankpin 333 material. The said force control member 334 has a length 3342 which is equal to the crankpin length 33312, in addition to a circumferential uniform thickness 3341 which is at most equal to the bearing shell thickness 3320. The circumferential extension angle 3343 of the said force control member 334 is equal to the corresponding extension angle 33313 of the recess, which is also equal to the conventional RICE typical crankpin-con rod force distribution extension angle 3240. When fixing the force control member 334 to the recess 3331 their extension angle bisectors 33401 and 3314, should coincide with each other, wherein the outer surface of the force control member 334 forms, together with the outer surface of the crankpin 333 the mating surface with the inner surface of the con rod bearing shell 322&323.

[0021] The objective of using the force control member 334 is to have control over the rate of action of the forces that act on the crankshaft 331 to increase the crankshaft output torque during the expansion stroke. For example, the efficiency-boosting arrangement tends to provide a slower acting force on the crankshaft than the con rod force during the expansion stroke, thereby, significantly enhancing the engine efficiency.

[0022] It is well known in the mechanical art that, at the TDC of the expansion stroke where the gas force is maximum, the crankshaft output energy is zero since at that position; the centers of the piston, crankpin and crankshaft are collinear. Therefore, at the commencement of the expansion stroke, the said efficiency boosting arrangement 30 intends to provide a smart means to slow down the crankpin force action rate on the crankshaft until it gets a significant torque arm, therefore, producing useful energy. FIG. 4a demonstrates the difference between the conventional con rod force 3241 &324, which represents a fast-acting force. A fast force at the TDC of the expansion stroke is notrecommended since at this instant the torque arm is zero while the gas pressure is maximum wherein this invention is aimed to make use of the maximum as well as other gas forces to provide useful output energy. To elaborate more on this, the expansion stroke is divided into four phases:• Phase 1 : In this phase, the efficiency-boosting arrangement transmits the whole gas force with a time lag of a fraction of a millisecond. At TDC of the expansion stroke wherein piston 31 applies the maximum gas force 3121 on the con rod 32 which, conventionally, is applied over the crankpin 333 outer surface as given by 3241 &324, however, due to the force control member 334 effect, the reaction contact force 3350 is being built up slower than the applied force 3241 &324 instigating the so-called “dynamic force lag concept (DFLC)” as depicted in FIG. 4a. Figure 4b represents the force control member 334 of the efficiency-boosting arrangement 30 by an elastic spring and a dashpot at the start of the expansion stroke that will be used to demonstrate the effect of DFLC by a simulation test as will be shown later in FIG 5.• Phase 2: In this phase, the efficiency-boosting arrangement continues to play a dominant role in transmitting most of the gas force with a time lag of a fraction of a millisecond. This phase takes place in the angular interval where the bisector 3314 or 33401 has just passed the TDC of the expansion stroke to a crank angle, which is equal to half of the extension angle 33313 or 3343. During this phase, the crankpin force distribution is a mix of the mutual contact force F_32 324 and the effect of the force control member 334 force, F_32AM 3350 as given by the distribution curves 3332&3350 wherein the contact force split into two portions (components) one component 3332 leads the other component 3350. Both components enhance the crankshaft output energy positively. It is worth noticing that, while at TDC of phase 1 , the efficiency-boosting arrangement is fully active, thereby the so-called DFLC takes place and then as the crank rotates during the expansion stroke, both of the fast-leading component 3332 provided by the crankpin 333 and the lagging component 3350 provided by the efficiency-boosting arrangement 30, i.e., a Dynamic Force Split Concept (DFSC) takes place. Therefore, during phase 2; the efficiency-boosting arrangement 30 allows the DFLC and DFSC to take place during the expansion stroke simultaneously.• Phase 3: In this phase, the crankpin plays a main role in transmitting most of the remaining gas force with no time lag. This phase takes place during the expansion stroke, where the angular interval of phase 3 when the bisector 3314 or 33401 has just passed a crank angle, which is equal to one-half of the extension angle 33313 or 3343 to a crank angle which is equal to the extension angle 33313 or 3343. During this phase, the crankpinforce distribution of the mutual contact force F_32 324 leads the force provided by the force control member 334 force, F_32AM 3350 wherein the contact force split into two components one component leads F_32 324 the other component F_32AM 3350. In this phase, only the Dynamic Force Split Concept (DFSC) takes place.• Phase 4: This phase takes place as the bisector 3314 or 33401 has just passed a crank angle, which is equal to the expansion angle 33313 or 3343 till the end of the expansion stroke. During this phase, the efficiency-boosting arrangement is inactive since it gets out of the mutual gas force contact with the con rod bearing shell as shown in the simulation results 332 and 3350 depicted in FIGS 5b and 5c.

[0022] During the expansion stroke, the connecting rod applies the force F_32 3241 on the crankpin 333, the force transmitted to the crankshaft 331 depends on the influence of the efficiency-boosting arrangement 30 wherein the force F_32AM 3350, which is due to the effect of the force control member 334 lags the applied force F_32 3241 since the member 334 is compressed elastically by an amount u as shown in fig. 4 and, therefore, the said force control member 334 responds by an elastic force F_32AM 3350 whether it is in fully contact, i.e., phase 1 , partially contact (phase 2 and phase3), while in phase 4, the efficiency-boosting arrangement does not affect the contact force distribution since it does not have contact with bearing shell 322.

[0023] To demonstrate the effectiveness of the efficiency-boosting arrangement, a singlecylinder spark ignition engine is used in the simulation comparison of the test results between the conventional and modified engines as shown in Fig 5. Figure 5a depicts the cylinder gas pressure 22 versus engine cylinder volume, while Figure 5b shows a comparison between the mutual contact forces between the con rod bearing shell 322 and the crankpin 333 for conventional 324 and modified 3350 & 3332 engines, wherein, it is observed that, from the commence of the expansion stroke till an angle equal to the extension angle value 3240 of a crankshaft rotation, the curves for the modified engine are slower acting on the crankshaft than those of the conventional engine. The impact of the lagged forces on the output crankshaft energy is well demonstrated in Fig 5c. Fig 5c exhibits the produced torque of the conventional 33361 , 3363 (mean torque) and modified 3362, 3364 (mean torque) engines wherein the output energy of the modified engine is substantially increased without adding extra fuel. Fig 5d illustrates a comparison of the characteristic performance curves for the conventional 3371 (torque) and 3373 (power)and the modified 3372 (torque) and 3374 (power) engines from which the superiority of the modified engine due to the present invention over the conventional engine is apparent.

[0024] Figs 6 and 7 illustrate a second exemplary embodiment of the present invention describing a V-type engine with its efficiency-boosting arrangement. In this embodiment, each of the two juxtaposed connecting rods 32 shares the same elongated crankpin 333 and the same elongated efficiency-boosting assembly 30. As shown in Figs 6 and 7, the efficiency-boosting arrangement 30 comprises a recess 3331 which is geometrically cut in the elongated crankpin 333 outer surface with an extension angle 33313, a length 33312 which is equal to the elongated crankpin axial length and a cut depth 33311 having a depth value equal to, at most, the con rod bearing shell thickness 3320. The bisector of the recess extension angle 33313 is the shortest line 3314 joining the crankshaft axis 3310 and the crankpin axis 3330. As illustrated in the first exemplary embodiment of the present invention, the recess 3331 is adapted to receiving the force control member 334, which fits in and is fixed to the said recess 3331 provided for significantly boosting the transmission of ferees from the connecting rod 32 to the crankshaft 331. When fixing the force control member 334 to the recess 3331 , its extension angle bisector 33401 coincides with the said recess extension angle bisector 33314. As shown in Figs 6 and 7, each efficiency boosting assembly 30 is allocated for two juxtaposed connecting rods 32 wherein according to firing order when one of them is at the TDC of the expansion stroke, the other one has a different function.

[0025] Figure 8A illustrates an exploded view of a Reciprocating Internal Combustion Engine (abbreviated to RICE) 700 provided by the present disclosure. Figure 8B illustrates an exploded side view of a connecting rod and crankpin of a connecting rod and crankpin assembly of the present disclosure. The RICE 700 comprises: a cylinder block 710 defining a set of cylinders; a set of pistons 720; and, a connecting rod and crankshaft assembly 800.

[0026] The cylinder block 710 defines a plurality of cylinders 711-714. Each cylinder 711- 714 has a longitudinal axis line of stroke 711 L-714L respectively. The set of pistons 720 comprises a corresponding number of pistons to cylinders in the cylinder block. In the present example, four pistons 721-714 are provided, one for each of the cylinders 711- 714, e.g. a first piston 721 in first cylinder 711 and so on.

[0027] Each piston 721-724 is configured to reciprocate within a respective cylinder 711. As a piston reciprocates within a cylinder, the piston moves along the longitudinal axis line of stroke of the cylinder (e.g. line 711 L for first piston 711 in first cylinder 721). Each piston reciprocates between a top dead centre (TDC) position and a bottom dead centre (BDC) position. For each cylinder-piston pair, the piston is configured to reciprocate within the cylinder along the said axis line of stroke between the Top dead centre, TDC, and Bottom dead centre. Figure 8A has a first line indicative of the TDC (labelled TDC) and a second line indicative of BDC (labelled BDC). That is, when a top surface of a piston touches the TDC, that piston is considered at the TDC position. Likewise, when a bottom surface of a piston touches the BDC, that piston is considered at the BDC position.

[0028] As will be appreciated by those skilled in the art, the cylinder block and piston set shown in Figure 8A are merely illustrative and in practice the cylinder block may comprise any number of cylinders, for example, 1 cylinder, 2 cylinders, 4 cylinders, 6 cylinders, 8 cylinders or any positive integer of cylinders. A corresponding number of pistons may be provided respectively, e.g. 1 piston for 1 cylinder, 2 pistons for 2 cylinders etc.

[0029] The connecting rod and crankshaft assembly 800 comprises: a set of connecting rods 810 having a big end; and, a crankshaft 820.

[0030] The set of connecting rods 810 (sometimes referred to simply as con rods) comprises a connecting rod for each piston. In the present example, four connecting rods 811-814 are provided e.g. a first connecting rod 811 and so on. Each connecting rod has a first end connected to a piston (e.g. first connecting rod 811 has a first end connected to the first piston 721). Each connecting rod has a second end distal to the first end. The second end is referred to as a big end (because it is larger than the first end) and shown in Figure 8A with reference signs 811 B, 812B, 813B, & 814B of connecting rods 811-814 respectively.

[0031] Each crankpin has an outer mating surface which has a circumferential recess. The circumferential recess is a recess configured to receive a force control member (described in more detail below). The recess has a circumferential angular extent equal to a circumferential extension angle. The circumferential extension angle may be arranged so that when the piston is in the TDC position of the expansion stroke, the circumferential extension angle is bisected by the said axis line of stroke. The circumferential extensionangle may preferably equal to the conventional engine connecting rod force distribution circumferential angle over the crankpin journal.

[0032] The recess has an axial extent orthogonal or substantially orthogonal to the direction of the circumferential extension angle. Each recess has a uniform depth (e.g. referred to as a depth of cut elsewhere herein). The depth of cut of a given recess is equal to (or in examples greater than) the thickness of the connecting rod bearing shell 851 . The geometrical recess is disposed along the entire length of the said crankpin in a direction parallel to its axis.

[0033] For each big end, bearing shell is provided between an inner mating surface of the big end and the crankpin outer mating surface. A force control member is provided for each of the crankpins disposed in said recess. Each force control member 741-744 is sized to fit within the geometrical recess of an outer surface of the crankpin e.g. circumferentially, axially and radially (e.g. thickness)). In examples, the entire outside surface of the crankpin together with the outside surface of the said force control member of the efficiency-boosting assembly has a circular cross-section that cooperates with the said bearing shell.

[0034] For example, each force control member may comprise an elastic metal (e.g. the term durable elastic metal may refer to a metal, having less stiffness than the stiffness of said crankpin material). When configured to use (e.g. when the arrangement is assembled) the force control member is mounted in and fixed to a geometrical recess of a crankpin.

[0035] The crankshaft 820 comprises a set of crankpins 830, one for each connecting rod. In the present example, four crankpins 831-834 are provided e.g. a first crankpin 831 and so on. Each crankpin is configured to engage a respective connecting rod (e.g. a big end of said connecting rod).

[0036] In particular each big end 811 B-814B of each connecting rod 811-814 is configured to engage a respective crankpin 831-824 of the crankshaft 820. In particular, the first big end 811 B of the first connecting rod 811 is coupled to the first crankpin 831 . A first force control member is disposed within the recess of the first crankpin 831 and contacts the big end 811 B of the first connecting rod 811. The same is true of the second, third, andfourth connecting rods, crankpins, and force control members. The crankpins and force control members are disposed within a bearing shell (e.g. a first bearing shell 851 is shown in Figure 8B) which rotatably mounts the crankpin with respect to the connecting rod. Each bearing shell is enclosed by a connecting rod big end and a connecting rod closure (e.g. Figure 8B shows a connecting rod big end 811 B and connecting rod closure 811C which are connectable by bolts 900 thereby to enclose the bearing shell 851).

[0037] The arrangement shown in Figures 8A & 8B operates in the same manner as other arrangements described herein. Each force control member provides a comparative increase in the time taken to transmits force from the combustion of a fuel-air mixture via the piston to the crankshaft via the crankpin. This is illustrated when considering the stroke of any given piston of the RICE 800 over a full cycle.

[0038] At TDC the combustion of the fuel-air mixture imparts a maximum force on the piston which transfers is transferred to the connecting rod which, which in turn is transferred to the crankpin via the force control member. The force control member has a stiffness less than the crankpin and / or the connecting rod, therefore, the force travels from the piston to the crankpin comparatively slower using the arrangement of the present disclosure compared to a typical RICE e.g. a RICE without the force control member. This concept may be referred to a “dynamic force lag concept (DFLC)”. The comparative time lag of force transmission using the arrangements of the present disclosure provide an effective lag of the force. Essentially the force is applied slightly ‘behind’ the motion of the crankpin thereby resulting in a portion of the maximum force (provided when the piston is disposed at the TDC position) being provided in the same direction as the direction of motion of the crankpin. In this way the RICE 800 (and other RICEs provided by the disclosure) are comparatively more efficient than typical RICEs.

[0039] It will also be appreciated that the connecting rod and crankshaft assembly 820 (or any other connecting rod and crankshaft assembly described herein) could be provided separate from the rest of a RICE e.g. for the purpose of retrofit of existing typical RICEs, for example, whereby the typical connecting rod and crankshaft assembly of the typical RICE is swapped out for a connecting rod and crankshaft assembly of the present disclosure.

[0040] The previous description of the preferred exemplary embodiments of the present invention has been presented for illustration per the provisions of the Patent Statutes. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obvious modifications or variations are possible considering the above teachings. The embodiments disclosed hereinabove were chosen to best illustrate the principles of the present invention and its practical application to thereby enable those of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated, if the principles described herein are followed. Thus, changes can be made in the above-described invention without departing from the intent and scope thereof. It is, also intended that the scope of the present invention be defined by the claims appended thereto.I. Terms

[0041] The term "invention" and the like mean "the one or more inventions disclosed in this application", unless expressly specified otherwise.

[0042] The terms “an aspect”, "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", "certain embodiments", "one embodiment", "another embodiment" and the like mean "one or more (but not all) embodiments of the disclosed invention(s)", unless expressly specified otherwise.

[0043] A reference to "another embodiment" or “another aspect” in describing an embodiment does not imply that the referenced embodiment is mutually exclusive with another embodiment (e.g., an embodiment described before the referenced embodiment), unless expressly specified otherwise.

[0044] The terms "including", "comprising" and variations thereof mean "including but not limited to", unless expressly specified otherwise.

[0045] The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise.

[0046] The term "e.g." and like terms mean "for example", and thus does not limit the term or phrase it explains.

[0047] The term "i.e." and like terms mean "that is", and thus limits the term or phrase it explains. For example, in the sentence "the computer sends data (i.e., instructions) over the Internet", the term "i.e." explains that "instructions" are the "data" that the computer sends over the Internet.

[0048] Where two or more terms or phrases are synonymous (e.g., because of an explicit statement that the terms or phrases are synonymous), instances of one such term / phrase does not mean instances of another such term / phrase must have a different meaning. For example, where a statement renders the meaning of "including" to be synonymous with "including but not limited to", the mere usage of the phrase "including but not limited to"does not mean that the term "including" means something other than "including but not limited to".

[0049] Neither the Title (set forth at the beginning of the first page of the present application) nor the Abstract (set forth at the end of the present application) is to be taken as limiting in any way as the scope of the disclosed invention(s). An Abstract has been included in this application merely because an Abstract of not more than 150 words is required under 37 C.F.R. sctn.1.72(b). The title of the present application and headings of sections provided in the present application are for convenience only, and are not to be taken as limiting the disclosure in any way.

[0050] Numerous embodiments are described in the present application, and are presented for illustrative purposes only. The described embodiments are not, and are not intended to be, limiting in any sense. The presently disclosed invention(s) are widely applicable to numerous embodiments, as is readily apparent from the disclosure. One of ordinary skill in the art will recognize that the disclosed invention(s) may be practiced with various modifications and alterations, such as structural and logical modifications. Although particular features of the disclosed invention(s) may be described with reference to one or more particular embodiments and / or drawings, it should be understood that such features are not limited to usage in the one or more particular embodiments or drawings with reference to which they are described, unless expressly specified otherwise.II Overview

[0051] The "Efficiency-Boosting Arrangement for Reciprocating Internal Combustion Engines" is a groundbreaking solution designed to enhance the efficiency of internal combustion engines. It addresses a long-standing problem where engines lose efficiency during the expansion stroke, particularly at the Top Dead Center (TDC) position. This invention optimizes force distribution, significantly boosting engine efficiency without requiring complex modifications or added fuel consumption.Key Features:• Simplicity and Cost-Effectiveness: A straightforward, affordable solution applicable to various reciprocating engines.• Improved Energy Conversion: Maximizes the use of gas pressure for enhanced engine performance and efficiency.• Versatility: Can be adapted to different reciprocating engine types and sizes• Environmental Impact: Reduces emissions, contributing to sustainability

[0052] In essence, this invention offers a cost-effective, adaptable, and environmentally responsible solution to a long-standing engine efficiency challenge.The present disclosure also comprises the following numbered clauses, which define embodiments of the disclosure:Clause 1. A Reciprocating Internal Combustion Engine (RICE) comprising a cylinder block defining at least one cylinder having a longitudinal axis line of stroke, a piston configured to reciprocate within the cylinder along the said axis line of stroke between the Top and Bottom dead centers, a connecting rod and a crankshaft assembly, the connecting rod and the crankshaft assembly comprising, a connecting rod, a crankshaft, the crankshaft comprising, a crankpin, the crankpin comprising, an outer mating surface, the assembly also comprising, a bearing shell arranged between the inner mating surface of the big end of the con rod and the crankpin outer surface, the said crankpin outer surface having a circumferential geometrical recess with a specified depth of cut and a precise circumferential extension angle, wherein an efficiency boosting assembly fitted to the said geometrical recess thereby substantially enhancing the efficiency of the engine.Clause 2. The RICE according to clause 1 wherein the said geometrical recess has a specified uniform depth of cut in the direction of the circumference of the outer matingsurface, the said geometrical recess depth is at most equal to the said bearing shell thickness wherein the said recess cut is made along the entire length of the said crankpin and parallel to its axis.Clause 3. The RICE according to clauses 1 and 2, wherein the said geometrical recess has a circumferential arc length, which has a specified extension angle wherein at the TDC the said geometrical recess extension angle is bisected by the said axis line of stroke, which intersects the axes of the said crankpin and the said crankshaft simultaneously.Clause 4. The RICE according to clauses 2 and 3, wherein the value of the said extension angle of the geometrical recess is equal to the conventional engine con rod force distribution circumferential angle over the crankpin journal, which is bisected by the axis line of stroke at the TDC position of the expansion stroke.Clause 5. The RICE according to clauses 1 , wherein the said efficiency boosting assembly comprises a force control member, the said force control member influences the rate of force transmission to the crankshaft; the said force control member is mounted in and fixed to the said geometrical recess.Clause 6. The RICE according to clauses 5, wherein the said force control member is made of a reliable and durable elastic metal, which has less stiffness than the stiffness of the said crankpin material where the relative stiffness between the force control member and the said crankpin material plays an important role in slowing down the gas force transmission from the piston to the crankshaft thereby, significantly enhancing the engine efficiency.Clause 7. The RICE according to clauses 5 and 6, wherein the said force control member has dimensions and shape to fit properly in the said geometrical recess.Clause 8. The RICE according to clauses 5 to 7, wherein said the force control member has a uniform thickness in the direction of the circumference of the outer mating surface, which is at most equal to the thickness of the said bearing shell.Clause 9. The RICE according to clauses 1 to 8, wherein the said force control member is arranged in the said geometrical recess defined in the said crankpin, where the entireoutside surface of the crankpin together with the outside surface of the said force control member of the efficiency-boosting assembly has a circular cross-section that cooperates with the said bearing shell.Clause 10. The RICE crankpin of the crankshaft according to clauses 5 and 7, wherein the value of the said extension angle of the force control member is equivalent to the conventional engine con rod force distribution circumferential angle over the crankpin journal, which is bisected by the axis line of stroke at the TDC position of the expansion stroke.

Claims

CLAIMS1. A Reciprocating Internal Combustion Engine, RICE, comprising: a cylinder block defining a cylinder having a longitudinal axis line of stroke, a piston configured to reciprocate within the cylinder along the said axis line of stroke between the Top dead centre, TDC, and Bottom dead centre; and, a connecting rod and crankshaft assembly, the connecting rod and crankshaft assembly comprising, a connecting rod having a big end, a crankshaft, the crankshaft comprising, a crankpin, the crankpin comprising, an outer mating surface, the connecting rod and crankshaft assembly also comprising, a bearing shell arranged between an inner mating surface of the big end and the crankpin outer mating surface, the said crankpin outer mating surface having a circumferential recess with a depth of cut and a circumferential extension angle, and, a force control member disposed in the said recess.

2. The RICE according to claim 1 wherein the said geometrical recess has a uniform depth of cut in the direction of the circumference of the crankpin outer mating surface, the said geometrical recess depth is at most equal to the said bearing shell thickness wherein the said recess cut is made along the entire length of the said crankpin in a direction parallel to its axis.

3. The RICE according to claims 1 and 2, wherein the said geometrical recess has a circumferential arc length, which corresponds to the circumferential extension angle wherein at the TDC position of the expansion stroke the said circumferential extension angle is bisected by the said axis line of stroke.

4. The RICE according to claims 2 and 3, wherein the value of the said circumferential extension angle of the geometrical recess is equal to the conventional engine con rod force distribution circumferential angle over the crankpin journal, which is bisected by the axis line of stroke at the TDC position of the expansion stroke.

5. The RICE according to claim 1 , wherein the force control member is mounted in and fixed to the said geometrical recess.

6. The RICE according to claim 5, wherein the said force control member comprises an elastic metal.

7. The RICE according to any of claims 5 to 6, wherein the force control member has less stiffness than the stiffness of the said crankpin.

8. The RICE according to claims 5 to 7, wherein the said force control member is sized to fit within the said geometrical recess.

9. The RICE according to claims 5 to 8, wherein said the force control member has a uniform thickness in the direction of the circumference of the outer mating surface, which is at most equal to the thickness of the said bearing shell.

10. The RICE according to claims 1 to 9, wherein the said force control member is arranged in the said geometrical recess defined in the said crankpin, where the entire outside surface of the crankpin together with the outside surface of the said force control member of the efficiency-boosting assembly has a circular cross-section that cooperates with the said bearing shell.

11. The RICE according to any of claims 1 to 10, wherein the force control member has a thickness equal to the depth of the circumferential geometrical recess.

12. The RICE according to claims 5 and 11 , wherein the value of the said extension angle of the force control member is equivalent to the conventional engine con rod force distribution circumferential angle over the crankpin journal, which is bisected by the axis line of stroke at the TDC position of the expansion stroke.

13. The RICE according to any of claims 1 to 12, wherein: the engine block comprises a plurality of cylinders; the RICE further comprising: a piston for each cylinder;a connecting rod for each piston; and, a crankpin for each connecting rod.

14. A connecting rod and crankshaft assembly for a reciprocating internal combustion engine, RICE, the connecting rod and crankshaft assembly comprising: a connecting rod having a big end a crankshaft, the crankshaft comprising, a crankpin, the crankpin comprising, an outer mating surface, the connecting rod and crankshaft assembly also comprising, a bearing shell arranged between an inner mating surface of the big end and the crankpin outer mating surface, the said crankpin outer mating surface having a circumferential recess with a depth of cut and a circumferential extension angle, and, a force control member disposed in the said recess.

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