Cam drive system for an engine and method for driving the cams of an engine

Abstract

Front end of an engine, comprising: a first end of a crankshaft (132); an idler gear assembly (404) comprising an idler gear (406) and a tensioner pulley (408), the idler gear (406) being in meshing engagement with the first end of the crankshaft (132), the tensioner pulley (408) being connected to the idler gear (406) and having a common axis of rotation therewith; first and second camshaft pulleys (142, 144) positioned vertically above the idler gear assembly (404); a cam drive belt (146) contacting the first and second camshaft pulleys (142, 144) and the tensioner pulley (408), respectively; and a fuel pump drive gear in direct meshing engagement with the idler gear, the fuel pump drive gear (412) being directly connected to a drive shaft (415) of a fuel pump (416), the fuel pump (416) being positioned in a direction of the axis of rotation of the idler gear between pistons of the engine and the idler gear (406) and the fuel pump drive gear (412).

Description

Area

[0001] This description generally relates to methods and systems for a cam drive system of an engine. Background / Summary

[0002] In a vehicle, the installation space for an engine may be limited. In particular, the height, length, and / or width of an engine may be limited by the size of the vehicle. However, fitting the large number of engine components, particularly a diesel engine, into a frame of smaller vehicles may be difficult. For example, the front end of an engine may include multiple drive mechanisms for driving engine components using rotational energy from an engine crankshaft. In particular, camshafts may be driven by camshaft pulleys that are rotationally connected directly to a crankshaft by a drive belt. However, the present inventors have recognized that connecting the camshaft pulleys directly to the crankshaft by means of a belt increases the size of the pulleys required to maintain a desired gear ratio between the crankshaft and the camshafts.Due to the larger size of the camshaft pulleys, such systems increase the overall height and / or width of the engine.

[0003] For example, DE 10 2004 033 948 A1 discloses a combined pump / camshaft drive in which a fuel pump is driven via an intermediate gear that meshes with a crankshaft output gear, said intermediate gear having an additional tooth track via which the camshafts are driven.

[0004] Furthermore, from the document DE 60 2004 005 489 T2 a fuel pump drive for fuel pumps with plunger pistons is known, wherein the said plungers are driven via rotating cams in order to generate time-controlled pump strokes.

[0005] Furthermore, DE 601 20 342 T2 shows an internal combustion engine in which a timing chain drives two overhead camshafts from a drive pinion on the crankshaft. Additionally, the crankshaft drives a belt drive that leads to a transmission.

[0006] The present invention is based on the object of creating an improved engine system and method that avoids the above-mentioned disadvantages. In particular, a compact design of the drives for the camshaft and the fuel pump of an engine is to be achieved.

[0007] According to the invention, the stated object is achieved by the front end of an engine according to claim 1, a method according to claim 11 and an engine system according to claim 16. Preferred embodiments of the invention are the subject of the dependent claims.

[0008] In one example, the problems described above may be solved by a front end of an engine comprising: a first end of a crankshaft; an idler gear assembly including an idler gear and an idler pulley, the idler gear assembly being in meshing engagement with the first end of the crankshaft, the idler pulley being connected to the idler gear and having a common axis of rotation therewith; first and second camshaft pulleys positioned vertically above the idler gear assembly; and a cam drive belt contacting the first and second camshaft pulleys and the idler pulley, respectively. In this way, by connecting the camshaft pulleys to the idler gear, the size of the camshaft pulleys can be reduced, and thus the size of the engine system can be correspondingly reduced.

[0009] In another embodiment, a method for an engine may include transmitting rotational motion from a crankshaft to an idler gear, the idler gear meshing with a first end of the crankshaft by means of a plurality of intermeshing teeth, rotating an idler pulley directly connected to the idler gear by means of rotation of the idler gear, the idler gear and the idler pulley having a common axis of rotation, and driving rotation of first and second camshaft pulleys by a cam drive belt driven by the idler pulley, the cam drive belt contacting an outer surface of the first and second camshaft pulleys and the idler pulley.

[0010] In yet another embodiment, a system for an engine may include a front end including a first end of a crankshaft, an idler gear assembly including an idler gear and an idler pulley, the idler gear meshing with the first end of the crankshaft, the idler pulley being connected to and having a common axis of rotation with the idler gear, first and second camshaft pulleys connected to first and second camshafts, respectively, and a cam drive belt contacting the first and second camshaft pulleys and the idler pulley, and not contacting the first end of the crankshaft, and a rear end disposed opposite the front end, the rear end including a flywheel connected to a second end of the crankshaft. In some examples, the idler gear may have more teeth than the first end of the crankshaft.Additionally or alternatively, the intermediate gear may have a larger diameter than the first end of the crankshaft.

[0011] Thus, due to its larger number of teeth and larger diameter, the idler gear can rotate at a slower speed than the crankshaft. By connecting the camshaft pulleys to the slower-rotating idler gear, the diameter of the camshaft pulleys can be reduced. By reducing the size of the camshaft pulleys, the overall size of the engine system can be reduced.

[0012] It should be understood that the foregoing summary is provided to introduce, in a simplified form, a selection of concepts that are further described in the detailed description. It is not intended to identify key or essential features of the claimed subject matter, the scope of which is determined solely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. Brief description of the drawings Fig. 1 shows a front perspective view of an exemplary engine system according to one or more embodiments of the present disclosure. Fig. 2 showed a perspective rear view of the exemplary engine system of Fig. 1 according to one or more embodiments of the present disclosure. Fig. 3 showed a side view of the exemplary engine system of Fig. 1 according to one or more embodiments of the present disclosure. Fig. 4 shows a perspective cross-sectional view of a front end of the exemplary engine system of Fig. 1, including a gear-driven diesel fuel injection pump, according to one or more embodiments of the present disclosure. Fig. 5 shows a cross-sectional view of a front end of the exemplary engine system of Fig. 1, including the gear-driven diesel fuel injection pump from Fig. 4, according to one or more embodiments of the present disclosure. Fig. Figure 6 shows a cross-sectional view of one side of the exemplary engine system of Fig. 1, including the gear-driven diesel fuel injection pump from Fig. 4-5, according to one or more embodiments of the present disclosure. Fig. Figure 7 shows a perspective view of the gear-driven diesel fuel injection pump of Fig. 4-6 according to one or more embodiments of the present disclosure. Fig. Figure 8 shows a perspective cross-sectional view of the front end of the exemplary engine system of Fig. 1, including the gear-driven diesel fuel injection pump from Fig. 4-7, according to one or more embodiments of the present disclosure. Fig. 9 shows a cross-sectional view of a cylinder head of the exemplary engine system of Fig. 1 and shows exemplary flow paths of engine coolant and engine exhaust gases through the cylinder head. Fig. 10 shows an exhaust gas recirculation (EGR) cooler used in the exemplary engine system of Fig. 1 is included. Fig. 11 shows a first cross-sectional view of the exemplary engine system of Fig. 1 included EGR cooler. Fig. 12 shows a second cross-sectional view of the exemplary engine system of Fig. 1 included EGR cooler. Fig. 13 shows a cross-sectional view of a motor used in the exemplary engine system of Fig. 1 included intake manifold. Fig. 14 shows a cross-sectional view of two in the exemplary engine system of Fig. 1 included cylinders. Fig. 15 shows a partial view of the exemplary engine system of Fig. 1 and illustrates a relative arrangement of two fuel injectors connected to the engine system. Fig. Figure 16 shows a group of fuel injectors designed for connection to the exemplary engine system of Fig. 1, with the group of fuel injectors being the two of Fig. 15 includes fuel injectors shown. Fig. 17 shows a fluid-carrying seal associated with an exhaust manifold of the exemplary engine system of Fig. 1 is connected. Fig. 18 shows an enlarged view of a fuel pump of the exemplary engine system of Fig. 1.

[0013] Fig. 1-18 are drawn to scale, but other relative dimensions may be used. Detailed description

[0014] The following description relates to systems and methods for mechanically driving a diesel fuel injection pump and for driving one or more camshafts of an engine system. A diesel engine, such as that of Fig. 1-8 and herein with reference to Fig. 1-18, may be operated with diesel fuel. The engine may include an exhaust gas recirculation (EGR) system having a plurality of passages formed in a cylinder head of the engine for flow of coolant and exhaust gases to an EGR valve assembly, as shown in Fig. 9. The EGR valve assembly is configured to direct coolant and exhaust gases to an EGR cooler, which includes a bypass passage connected to a baffle, as shown in Fig. 10-12. The baffle may direct gases from the bypass passage to an outlet of the EGR cooler and reduce a likelihood of gases from the bypass passage recirculating in the EGR cooler. The engine may additionally include an intake manifold with helical intake manifolds and non-helical intake manifolds positioned in an alternating arrangement (as shown in Fig. 13-14) to increase intake air swirl in the combustion chambers. Engine fuel injectors can be positioned at different angles to each other (as in Fig. 15-16) to shape a spray pattern from each fuel injector to accommodate the greater swirling amount of intake air. An exhaust manifold of the engine may include a heat-shielding gasket with multiple channels shaped to direct fluid (e.g., oil leaks) away from an exterior of the exhaust manifold, as shown in Fig. 17 is shown.

[0015] The engine may include a diesel pump for pumping fuel to combustion chambers of the engine. The pump may be driven by the engine. In particular, energy obtained from combustion of the fuel in the combustion chambers may be used to drive a rotational movement of a crankshaft, which may then be used to supply energy to the fuel pump. As in the examples of Fig. 4-8, the crankshaft may include a gear at a first end of the crankshaft near or at a forward end of the engine. The crankshaft gear may be in meshing engagement with an idler gear of an idler gear assembly such that rotational movement of the crankshaft drives rotational movement of the idler gear. The idler gear may be positioned between the crankshaft gear and a gear of a fuel pump drive shaft and may be in meshing engagement with both. In this way, rotational movement of the crankshaft may be transmitted to the fuel pump by means of the idler gear, and the rotational movement of the crankshaft may be transmitted to the idler gear, which is then transmitted to the fuel pump drive shaft. The rotational movement of the fuel pump drive shaft may drive a fuel pump piston, pressurizing fuel delivered to the combustion chambers.This allows the fuel pump to be driven by one or more gears rather than a belt or chain. In some examples, the fuel pump may be driven by a gear arrangement as shown in . Fig. 18, includes one or more scissor gears. Furthermore, driving the fuel pump using the gear drive system can reduce drive torque irregularities (e.g., those associated with a belt-driven system) and the resulting wear on fuel pump components, thereby extending the service life of the fuel pump.

[0016] The above-described and in Fig. The exemplary engine shown in FIGS. 1-8 may include camshafts that rotate to control the opening and closing timing of intake and exhaust valves of the engine's combustion chambers. The rotation of the camshafts may be driven by the engine's crankshaft at a particular gear ratio to maintain a desired angular velocity ratio between the camshafts and the crankshaft. In one example, the desired angular velocity ratio may be approximately 2:1, such that the camshafts make one complete rotation for approximately every two complete rotations of the crankshaft.

[0017] The camshafts may be connected to the idler gear assembly by means of a belt and respective pulleys, with the idler gear assembly being driven directly by the crankshaft by means of meshing teeth. The idler gear assembly can thus transmit torque from the crankshaft to the camshafts. As in the examples of Fig. 4-8, the idler gear assembly may include more teeth than a first end of the crankshaft with which it meshes. The idler gear assembly may rotate at a slower rate than the crankshaft. Due to the slower angular velocity of the idler gear assembly, the size of camshaft pulleys connecting the camshafts to the idler gear assembly may be reduced while maintaining the desired angular velocity relationship between the camshafts and the crankshaft. Thus, by reducing the size of the camshaft pulleys, the overall size of the engine may be reduced.

[0018] Fig. 1-18 illustrate the relative positioning of various components of an engine system. If they are shown directly contacting or directly connected to one another, then such components may be referred to as directly contacting or directly connected, at least in one example. Similarly, components shown continuous or adjacent to one another may each be continuous or adjacent to one another, at least in one example. For example, components in surface contact with one another may be referred to as being in surface contact or physically contacting one another. As another example, elements positioned apart from one another, with only a space and no other components between them, may be referred to as such, in at least one example.

[0019] As yet another example, elements shown above / below each other, on opposite sides of each other, or to the left / right of each other may be so referred to relative to each other. Further, as shown in the figures, in at least one example, a topmost element or point of an element may be referred to as a "top" of the component, and a bottommost element or point of the element may be referred to as a "bottom" of the component.

[0020] Furthermore, Fig. 1-18 illustrates an axis system 150 that can be used to describe the relative positioning of components of the motor system. The axis system 150 can include a vertical axis 152, a transverse axis 154, and a longitudinal axis 156. The axes 152, 154, and 156 can be orthogonal to one another, thereby defining a three-dimensional axis system. As used herein, "top / bottom," "upper / lower," and "above / below" can be relative to the vertical axis 152 and can be used to describe the positioning of elements of the figures relative to one another along the vertical axis 152. Similarly, "left of / right of" and "side of" can be used to describe the positioning of elements of the figures relative to one another along the transverse axis 154 and can be used to describe the positioning of elements of the figures relative to one another along the transverse axis 154.Furthermore, “in front of” and “behind” may be relative to the longitudinal axis 156 and may be used to describe the positioning of elements of the figures relative to one another along the longitudinal axis 156.

[0021] Thus, in one example, elements shown above other elements are positioned vertically above the other elements. As yet another example, shapes of the elements depicted in the figures may be referred to as having those shapes (e.g., formed as circular, straight, planar, curved, rounded, chamfered, angled, or the like). Elements shown intersecting one another may, in at least one example, be further referred to as intersecting elements or intersecting one another. Furthermore, in one example, an element shown inside another element or shown outside another element may be referred to as such.

[0022] Starting with Fig. 1 shows a front perspective view 100 of an exemplary engine system 10. The engine system 10 may include a front end 102 opposite a rear end 104, a top surface 106 opposite a bottom surface 108, and a first side 110 opposite a second side 112. The engine system 10 includes a cylinder head 114 connected to a cylinder block 116, which defines one or more combustion chambers 118 (which may be referred to herein as cylinders). Specifically, the combustion chambers 118 may be formed by one or more bores in the cylinder block 116, wherein the bores define the side and bottom walls of the combustion chambers 118. The cylinder head 114 may be positioned vertically above the cylinder block 116, and a bottom surface of the cylinder head 114, which is contiguous with a top surface of the cylinder block 116, may define the top wall of the combustion chambers 118. In the embodiments described herein with reference to Fig. 1-18, the engine system 10 includes four combustion chambers 118. However, it should be understood that in other examples, the engine system 10 may include more or fewer than four combustion chambers 118. Furthermore, in this description, combustion chambers 118 may also be referred to herein as cylinders 118.

[0023] The cylinders 118 may be arranged adjacent to and / or parallel to each other along the longitudinal axis 156 in what is commonly referred to by those skilled in the art as an "in-line" arrangement. Thus, the cylinders 118 may be arranged as a single row of cylinders. However, it should be understood that in other examples, the engine cylinders 118 may be arranged in multiple rows, such as in a "V" configuration.

[0024] Below the cylinder block 116, a crankcase skirt 119 can be positioned between the cylinder block 116 and an oil pan 120. Thus, the crankcase skirt 119 can be connected to the underside of the cylinder block 116, and the oil pan 120 can be connected to the underside of the crankcase skirt 119. Thus, the oil pan 120 can define the underside 108 of the engine system 10. In other words, the oil pan 120 can be positioned on the underside 108 of the engine system 10. The oil pan 120 can be a (in Fig. 1 not shown) oil pump, which pumps oil to various rotating engine components for lubrication.

[0025] By means of an intake tract 122, intake air can enter the engine system 10. Then, the intake air can be supplied by means of an integrated intake manifold 422 (in Fig. 4, Fig. 8 and Fig. 13 and is illustrated below using Fig. 13) to the combustion chambers 118. In particular, an amount of airflow to the combustion chambers 118 may be regulated by an intake throttle and / or one or more intake valves. Upon opening of the one or more intake valves, intake air may be introduced into the combustion chambers 118, such as during an intake stroke of a piston. The intake air may then be compressed during a compression stroke of the piston as the piston moves upward toward the cylinder head 114 and top dead center (TDC). Diesel fuel may be injected into each of the combustion chambers 118 by respective fuel injectors 124 positioned above the combustion chambers 118. In particular, diesel fuel may be injected directly into each of the cylinders 118 by the fuel injectors 124. The injected fuel may combust with the compressed intake air during a subsequent power stroke.After combustion, one or more exhaust valves 126 may open to allow the combustion products to exit from the combustion chambers 118 to an exhaust manifold 128.

[0026] The exhaust manifold 128 may connect the combustion chambers 118 to a common exhaust tract 130 for directing the combustion products from the combustion chambers 118 to the exhaust tract 130. One or more of the combustion chambers 118 may additionally be connected to an internal exhaust tract 902 formed by inner surfaces of the cylinder head 114 for directing exhaust gases to an EGR assembly 900 connected to the engine system 10 (as shown in Fig. 9 and described in more detail below). The exhaust tract 130 may include a turbine 131 of a turbocharger of the engine system 10. The turbine 131 may be connected to an intake compressor positioned within the intake tract 122 for compressing the intake air provided to the combustion chambers 118. After flowing through the turbine 131, exhaust gases may pass through a diesel particulate filter and / or other emissions control devices before being discharged to the environment.

[0027] The combustion of the air-fuel mixture in the combustion chambers 118 can drive a reciprocating motion of the pistons positioned in the combustion chambers 118. Movement of the pistons can be converted into rotational motion of a crankshaft 132, which can be used to deliver torque to one or more vehicle wheels. In particular, as described below with reference to Fig. 2, at the rear end 104 of the engine system 10, a flywheel 134 may be connected to a rear second end of the crankshaft 132 opposite a front first end 133 of the crankshaft 132. The front first end 133 of the crankshaft 132 may be positioned at or near the front end 102 of the engine system 10 and may include one or more gears and / or pulleys for driving various components of the engine system 10. For example, as shown in Fig. 1, the crankshaft 132 may include one or more outer first pulleys 136. One of the outer first pulleys 136 may be connected via a belt or chain to a water pump pulley 138 for driving a water pump 140 of the engine system 10. In particular, the water pump pulley 138 may be connected to the water pump 140 such that rotational movement of the pulley 138 drives the water pump 140. The outer first pulleys 136 may include additional pulleys that may be connected via belts and / or chains to various other engine components, such as an air conditioning compressor, for transferring power from the crankshaft thereto. The water pump 140 may supply water or coolant to the cylinder head 114, the cylinder block 116, and / or a radiator for cooling various components of the engine system 10.

[0028] The engine system 10 may include a front cover 141 at the front end 102 that protects and covers internal components of the engine system 10 at the front end 102. The outer first pulleys 136 and the water pump pulley 138 are shown positioned in front of or outside the front cover 141. Inside the front cover 141 and as described below with reference to Fig. 4-8, the crankshaft 132 may be connected to one or more gears and / or belts to drive rotational movement of an input camshaft pulley 142 and an output camshaft pulley 144. The pulleys 142 and 144 may be positioned adjacent to each other relative to the vertical axis 152 at or near the top 106 of the front end 102 of the engine system 10. Further, the crankshaft 123 may include a gear at the front first end 133 that is connected to an idler gear (hereinafter referred to with reference to Fig. 4-8), wherein the idler gear comprises a pulley connected to the camshaft pulleys 142 and 144 by a camshaft drive belt 146. The idler gear may be positioned relative to the front end 102 rearward and inward of the outer first pulleys 136. The camshaft pulleys 142 and 144 may be connected to separate camshafts. In the example of Fig. 1, only one exhaust camshaft 148 is shown. The camshafts can thus rotate with the camshaft pulleys 142 and 144 and can control the opening and closing timing of the intake and exhaust valves. In particular, the intake camshaft pulley 142 can be connected to the intake camshaft along the same rotational axis as an intake camshaft and can control the opening and closing timing of one or more intake valves. Similarly, the exhaust camshaft pulley 144 can be connected to an exhaust camshaft along the same rotational axis as the exhaust camshaft pulley 144 and can control the opening and closing timing of the exhaust valves 126. Thus, the exhaust camshaft can rotate at approximately the same speed as the exhaust camshaft pulley 144 and the intake camshaft can rotate at approximately the same speed as the intake camshaft pulley 142.The camshaft 148 may include camshaft lobes 149 that convert rotational movement of the camshaft 148 into linear movement of the exhaust valves.

[0029] As in the example of Fig. 1, the camshaft 148 may be positioned vertically above the cylinder block 116 in the cylinder head 114. Thus, the camshaft 148 may be positioned vertically above the crankshaft 132. Although in the example of Fig. 1, it should be understood that other examples may include more or fewer than two camshafts. Further, in some examples, engine system 10 may include a variable valve timing system or a variable cam timing system to adjust valve opening and / or closing timing.

[0030] Continue to Fig. 2 shows a perspective rear view 200 of the motor system 10. In detail, Fig. 2 a more detailed view of the rear end 104 of the engine system 10 including the flywheel 134. The flywheel 134 may be connected to the crankshaft 132 at a rear second end 233 of the crankshaft 132, the rear second end 233 being opposite the front first end 133 (in Fig. 2 not shown). Thus, the flywheel 134 may be connected to the crankshaft 132 at the rear end 104 of the engine system 10. The flywheel 134 may connect the crankshaft 132 to a vehicle transmission for transmitting torque from the crankshaft 132 to the transmission and one or more vehicle wheels.

[0031] Fig. 2 also shows an example of one or more pistons 202 positioned within one of the combustion chambers 118. The pistons 202 can translate up and down along the vertical axis 152 between TDC and bottom dead center (BDC).

[0032] Continue to Fig. 3 shows a first side view 300 of the engine system 10, which faces the first side 110 of the engine system 10. Shown are sections of two of the combustion chambers 118, exposing two of the pistons 202 positioned therein. Furthermore, the fuel injectors 124 are shown positioned above the combustion chambers 118, such that each of the combustion chambers 118 includes a dedicated fuel injector. The fuel injectors 124 may be connected to a fuel pump via fuel supply lines 302. Thus, the fuel supply lines 302 may be connected at a first end to the fuel injectors 124 and at an opposite second end to a (in Fig. 3 not shown) fuel pump.

[0033] With reference now to Fig. 4 and Fig. 5 show these cross-sectional views 400 and 500 of the engine system 10 at the front end 102 of the engine system 10, wherein the (above with reference to Fig. 1) is removed. This allows Fig. 4 and Fig. 5 are described together in this description. Thus, the Fig. 4 shows a cross-section of the engine system 10 at the front end 102 of the engine system 10 along a plane parallel to the plane defined by the vertical axis 152 and the transverse axis 154. The front cover 141 has been removed, exposing internal components of the engine system 10 at the front end 102 of the engine system 10. The Fig. 4 may thus be immediately adjacent and inward of the front cover 141 and the outer first pulleys 136 described above with reference to Fig. 1 and Fig. 3 were described.

[0034] The first end 133 of the crankshaft 132 may include a crankshaft gear 402 and / or an oil pump pulley 403. The crankshaft gear 402 and the oil pump pulley 403 may be connected to the crankshaft 132 and may share a rotational axis with the crankshaft 132. In particular, the pulley 403 and the gear 402 may be rotationally fixed relative to the crankshaft 132. The oil pump pulley 403 may also be referred to herein as an oil pump drive gear 403. The pulley 403 and the gear 402 may rotate with the crankshaft 132 and at substantially the same angular velocity as the crankshaft 132. Thus, the oil pump pulley 403 and the crankshaft gear 402 may be concentrically positioned about a central rotational axis of the crankshaft 132. The crankshaft gear 402 may be connected to an idler gear assembly 404. The oil pump pulley 403 may be connected to a (in Fig. 4) positioned in the oil pan 120. Thus, rotational movement of the crankshaft 132 can be transmitted to the oil pump by means of the belt 405 to drive and power the oil pump.

[0035] The crankshaft gear 402 can drive the idler gear assembly 404 by means of a meshing engagement between a plurality of teeth of the crankshaft gear 402 and a plurality of teeth 407 of the idler gear assembly 404. In particular, the idler gear assembly 404 can include an idler gear 406 and an idler pulley 408, with the idler gear 406 including the teeth 407. The idler gear 406 thus meshes with the first end 133 of the crankshaft 132. The idler gear 406 and the idler pulley 408 can integrally form the idler gear assembly 404. In some examples, the idler gear assembly 404 can thus comprise a single continuous piece that includes the idler gear 406 and the idler pulley 408. The idler gear 406, the idler pulley 408, and the idler gear assembly 404 can thus share a common axis of rotation.Furthermore, the idler gear 406, the tension pulley 408, and the idler gear assembly 404 may be rotationally fixed to one another so that they rotate in the same direction and at substantially the same angular velocity. The idler gear 406 may have a larger diameter than the tension pulley 408. Thus, for a given angular velocity of the idler gear assembly 404, the edges or teeth 407 of the idler gear 406 may have a greater linear velocity than the edges of the pulley 408 due to the larger diameter of the idler gear 406.

[0036] When the crankshaft 132, and thus the crankshaft gear 402, rotates, the meshing teeth of the crankshaft gear 402 and the idler gear 406 can cause the idler gear assembly 404 to rotate. Thus, the idler gear assembly 404 can be driven by rotating the crankshaft 132 via the meshing engagement of the teeth of the idler gear 406 and the crankshaft gear 402. The idler gear assembly 404 can rotate in a direction opposite that of the crankshaft 132. Thus, the crankshaft 132 can rotate in a first direction, and the idler gear assembly 404 rotates in a second direction, the second direction being opposite the first direction. For example, when the crankshaft 132 rotates in a counterclockwise direction as viewed from the front end 102 of the engine system 10, the idler gear assembly 404 rotates clockwise.

[0037] Furthermore, the idler gear 406 and the idler gear assembly 404 may rotate at a slower speed (a smaller angular velocity) than the crankshaft gear 402 and the crankshaft 132. In particular, the idler gear 406 may include more teeth than the crankshaft gear 402 and / or may include a larger diameter than the crankshaft gear 402 and thus may rotate slower than the crankshaft 132 when driven by the crankshaft gear 402. In one example, the idler gear 406 may include 63 teeth and the crankshaft gear 402 may include 45 teeth. In other examples, the idler gear 406 may include more or fewer than 63 teeth and / or the crankshaft gear 402 may include more or fewer than 45 teeth.

[0038] Furthermore, in some examples, the pitch of the crankshaft gear teeth and the idler gear teeth and / or the sizing of the teeth may be approximately equal to reduce slippage between the gears 402 and 406 and maintain meshing engagement between the two gears 402 and 406. Thus, in some examples, the idler gear 406 may have a larger diameter than the crankshaft gear 402 to accommodate its greater number of teeth. The idler gear 406 may additionally or alternatively be sized to separate the idler gear 406 and a fuel pump drive gear 412 with which it also meshes.The idler gear 406 may thus be sized based on one or more of: a desired distance between the crankshaft gear 402 and the fuel pump drive gear 412, a desired number of teeth of the teeth on the idler gear 406, a number of teeth on the crankshaft gear 402, a desired gear ratio or speed ratio between the idler gear 406 and the crankshaft gear 402, etc.

[0039] In other examples, however, the crankshaft gear 402 may have a larger diameter than the idler gear 406. Furthermore, in some examples, the pitch and / or dimension of the crankshaft gear teeth and the idler gear teeth may be different. In still other examples, the crankshaft gear 402 may include more teeth than the idler gear 406 and / or may rotate at a slower speed than the crankshaft gear 402.

[0040] The idler gear 406 may also be in meshing engagement with the fuel pump drive gear 412 via a plurality of intermeshing teeth. Specifically, teeth 407 of the idler gear 406 and teeth 414 of the fuel pump drive gear 412 may be in meshing engagement such that rotational movement of the idler gear assembly 404 drives rotational movement of the fuel pump drive gear 412. The fuel pump drive gear 412 may be connected to and share a rotational axis with a drive shaft 415 of a fuel pump 416. In some examples, the fuel pump drive gear 412 and the drive shaft 415 may be rotationally fixed such that they rotate at substantially the same angular velocity. The drive shaft 415 may drive a piston or other pressurizing element of the pump 416. In one example, the pump 416 may include a single plunger (e.g., piston) as described below.In other examples, however, the pump 416 may include more than one plunger or pressurizing element, and each plunger or pressurizing element may be driven by rotation of the drive shaft 415.

[0041] The rotary movement of the drive shaft 415 can thus be used to operate the pump 416, to displace the piston of the pump 416 and thus to supply the (in Fig. 4 (not shown) combustion chamber 118. In some examples, the piston of pump 416 may move linearly up and down twice for each complete rotation (e.g., 360 degrees of rotation) of crankshaft 132 (e.g., from top dead center to bottom dead center and from bottom dead center to top dead center). In this manner, crankshaft 132 may be used to operate pump 416. Specifically, rotational motion of crankshaft 132 may be transmitted via idler gear 406 and fuel pump drive gear 412 to drive shaft 415 of pump 416 to create the linear motion of the piston in pump 416.

[0042] The idler gear 406 and the idler gear assembly 404 can thus be positioned between the crankshaft 132 and the fuel pump drive gear 412 and can separate them. Furthermore, the idler gear assembly 404 can be positioned vertically above the crankshaft 132. The idler gear 406 can thus be in meshing engagement with the first end 133 of the crankshaft 132 and with the fuel pump drive gear 412 by means of the plurality of intermeshing teeth. Furthermore, the crankshaft 132, and in particular the crankshaft gear 402, may not be in meshing engagement with the fuel pump drive gear 412. Thus, the crankshaft gear 402 and the fuel pump drive gear 412 may be separated by the idler gear 406. Thus, the crankshaft 132 and the fuel pump drive gear 412 may not be in physical contact with each other.However, torque can still be transmitted between the crankshaft 132 and the fuel pump drive gear 412 by means of the intermediate gear 406 (e.g., by means of the intermediate gear 406 from the crankshaft 132 to the fuel pump drive gear 412).

[0043] The fuel pump drive gear 412 may have approximately the same diameter and / or the same number of teeth as the crankshaft gear 402. In such examples, the fuel pump drive gear 412 may thus have a smaller diameter than the idler gear 406 and may include approximately 45 teeth. Further, the fuel pump drive gear 412 may rotate at approximately the same angular velocity as the crankshaft 132. However, in other examples, the fuel pump drive gear 412 may have a larger or smaller diameter than the crankshaft gear 402, may include more or fewer teeth than the crankshaft gear 402, and / or may rotate at a different angular velocity than the crankshaft 132. Further, the fuel pump drive gear 412 rotates in the opposite direction of the idler gear 406. Thus, the fuel pump drive gear 412 rotates in the same direction as the crankshaft 132.

[0044] In this way, lateral loading of the fuel pump drive shaft 415 (e.g., forces against the fuel pump drive shaft 415 in radial directions relative to a rotational axis of the fuel pump drive shaft 415) and fuel pump bearings can be reduced relative to systems that utilize belts and pulleys to connect the crankshaft 132 to the fuel pump drive shaft 415 by incorporating the idler gear 406 as a torque-transmitting mechanism between the crankshaft 132 and the fuel pump drive shaft 415. Furthermore, friction losses between the fuel pump 416 and the crankshaft 132 can be reduced relative to systems that utilize belts and pulleys to connect the crankshaft 132 to the fuel pump drive shaft 415 by connecting the crankshaft 132 to the fuel pump drive shaft 415 via the idler gear assembly 404.Thus, friction and wear on the fuel pump 416 may be reduced, and durability of the fuel pump 416 may be reduced by reducing the load on one or more bearings of the fuel pump 416. Furthermore, by incorporating the idler gear 406, a distance between the crankshaft 132 and the fuel pump 416 may be reduced relative to systems that utilize belts and pulleys to connect the crankshaft 132 to the fuel pump 416, thereby reducing the size, packaging, and cost of the engine system 10.

[0045] The camshaft drive belt 146 may be driven by the idler gear assembly 404. Specifically, the camshaft drive belt 146 may contact an outer peripheral surface of the tension pulley 408. Thus, the camshaft drive belt 146 may rotate when the idler gear assembly 404 rotates. In this way, the crankshaft 132 may drive the camshaft drive belt 146 via the idler gear assembly 404. Specifically, the crankshaft 132 drives rotation of the idler gear assembly 404 by means of a meshing engagement between the first end 133 of the crankshaft 132 and the idler gear 406, and rotation of the idler gear 406 drives rotation of the camshaft drive belt 146 by means of the pulley 408, wherein the pulley 408 is directly connected to the idler gear 406 such that rotating the idler gear 406 by a first angular amount (e.g., degrees) rotates the pulley 408 by the same angular amount.In this way, the crankshaft 132 can drive rotation of the idler gear assembly 404, and the idler gear assembly 404 can drive rotation of both the camshaft drive belt 146 and the fuel pump drive gear 412. However, the camshaft drive belt 146 does not need to contact the crankshaft 132 (e.g., be in surface contact with it).

[0046] The camshaft drive belt 146 may additionally be connected to outer peripheral surfaces of the camshaft pulleys 142 and 144. Specifically, the camshaft pulleys 142 and 144 may include outer teeth 438 that may mesh with the camshaft drive belt 146. In some examples, the pulleys 142 and 144 may each include approximately 21 teeth. However, in other examples, the pulleys 142 and 144 may each include more or fewer than 21 teeth. The number of teeth on pulleys 142 and 144 and / or the sizing of pulleys 142 and 144 can be selected to achieve a 2:1 gear ratio between crankshaft 132 and pulleys 142 and 144, such that pulleys 142 and 144, as well as the camshafts, complete one full rotation every two full rotations of crankshaft 132. One full rotation can be defined as a rotation of 360 degrees.Thus, the camshafts and pulleys 142 and 144 can rotate 360 degrees for every 720 degrees that the crankshaft 132 rotates.

[0047] Rotation of the idler gear assembly 404 by means of the rotating crankshaft 132 may thus drive rotation of the camshaft drive belt 146, which in turn may drive rotation of the camshaft pulleys 142 and 144. The camshaft pulleys 142 and 144 may share a rotational axis with the camshafts. In particular, the intake camshaft pulley 142 may share a rotational axis with an intake camshaft 448, and the exhaust camshaft pulley 144 may share a rotational axis with the exhaust camshaft 148.The intake camshaft pulley 142 may be rotationally fixed to the intake camshaft 448 such that the camshaft pulley 142 and the camshaft 448 rotate at approximately the same angular velocity, and / or the exhaust camshaft pulley 144 may be rotationally fixed to the exhaust camshaft 148 such that the camshaft pulley 144 and the camshaft 148 rotate at approximately the same angular velocity. However, in other examples, a variable valve timing system may be included to adjust the relative rotational speed of the pulleys 142 and 144 and the camshafts 148 and 448 (e.g., to increase or decrease a rotational speed of the camshaft 148 and / or the camshaft 448 relative to a rotational speed of the pulley 142 and / or the pulley 144). As in the example of FIG. Fig. 4, the camshafts 148 and 448 and the camshaft pulleys 142 and 144 may be positioned vertically above the idler gear assembly 404.

[0048] In this manner, the belt 146 may connect the idler gear assembly 404 to the camshaft pulleys 142 and 144. The belt 146 may be connected directly to the tensioner pulley 408 and not connected to the crankshaft 132. Thus, rotational motion of the crankshaft 132 may be transmitted by the belt 146 first to the idler gear assembly 404 and then from the idler gear assembly 404 to the camshaft pulleys 142 and 144. The belt 146 may form a closed loop around the outer surfaces of the tensioner pulley 408 and the camshaft pulleys 142 and 144. Thus, the linear velocity of the camshaft pulleys 142 and 144 at the outer edges or teeth of the pulleys 142 and 144 may be approximately equal to the linear velocity of the tension pulley 408 at the outer surface of the pulley 408.Furthermore, due to the rotating belt 146 connecting the pulleys 142 and 144 to the idler gear assembly 404, the camshaft pulleys 142 and 144 can rotate in the same direction as the idler gear assembly 404. Thus, the camshaft pulleys 142 and 144 can rotate in a direction opposite to the crankshaft. Thus, the crankshaft 132 can rotate in a first direction, and the idler gear assembly 404 and the pulleys 142 and 144 can rotate in a second direction, the second direction being opposite to the first direction. For example, when the crankshaft 132 rotates in a counterclockwise direction as viewed from the front end 102 of the engine system 10, the pulleys 142 and 144 rotate clockwise.

[0049] The engine system 10 may further include a tensioning device 410. As in the example of Fig. 4, the tensioning device 410 may be positioned vertically above the idler gear assembly 404. The tensioning device 410 may be rotatable and may be biased by a biasing element (e.g., a spring) to rotate in one direction. In the example of Fig. 4, the biasing element of the tensioner 410 can bias the tensioner 410 to rotate counterclockwise as viewed from the front end 102 of the engine system 10. Thus, the tensioner 410 can exert a transverse force to the left (e.g., along the transverse axis 154 in the positive direction) against the belt 146, and the belt 146 can correspondingly exert a normal force in a direction opposite the transverse force against the tensioner 410 (e.g., along the transverse axis 154 to the right and in the negative direction). The transverse force against the belt 146 from the tensioner 410 can pull the belt 146 taut against the pulley 142, the pulley 144, and the idler pulley 408. In this way, the tensioner 410 can maintain the tension in the belt 146 at a substantially constant amount.The tensioner 410 may contact an outer first surface 411 of the belt 146, while the pulleys 142 and 144 and the tensioner roller 408 may contact an opposite inner second surface 413 of the belt 146.

[0050] Due to its larger diameter and / or its greater number of teeth relative to the crankshaft gear 402, the idler gear 406 can rotate at a lower angular velocity than the crankshaft 132. When connected to the idler gear assembly 404, the belt 146 can thus rotate at a lower speed than when connected to the crankshaft 132. Since the speed of the belt 146 can be reduced, the diameter of the camshaft pulleys 142 and 144 can be reduced in the Fig. 4, relative to engine systems in which the camshaft belt is directly connected to the crankshaft 132, the desired angular velocity ratio may be reduced to achieve a desired angular velocity ratio between the crankshaft 132 and the camshaft pulleys 142 and 144. For example, the desired angular velocity ratio between the crankshaft 132 and the camshaft pulleys 142 and 144 may be approximately 2:1, such that the camshaft pulleys 142 and 144 and the camshafts 148 and 148 complete approximately one complete rotation for every two complete rotations of the crankshaft 132. However, it should be understood that the desired angular velocity ratio may be greater or less than 2:1 in other examples.By reducing the diameter of the camshaft pulleys 142 and 144, the overall size, packaging, and cost of the engine system 10 may be reduced relative to the system in which the camshaft belt is directly connected to the crankshaft 132. In some examples, the diameters of the camshaft pulleys 142 and 144 may be approximately the same. However, in other examples, the diameters of the camshaft pulleys 142 and 144 may be different.

[0051] The engine system 10 may further include an exhaust gas recirculation (EGR) system, as shown in Fig. 9-12 and described below. In particular, the engine system 10 may include a high-pressure exhaust gas recirculation system in which exhaust gases flow through an exhaust passage formed inside the cylinder head, through an EGR assembly and an EGR cooler, and to a location downstream of the turbocharger compressor in the intake passage 122. Additionally or alternatively, the engine system 10 may include a low-pressure EGR system in which an LP EGR passage (LP = short for low pressure) connects the exhaust passage downstream of the turbocharger turbine to a location upstream of the turbocharger compressor in the intake passage 122. In this way, exhaust gases may be recirculated to the intake passage 122. The intake passage 122 is in Fig. 4 with an intake throttle valve 418 that can regulate an amount of air flowing into the engine system 10.

[0052] The EGR passage 420 may connect an EGR cooler 424 to the engine intake. In examples where the EGR system is configured as a HP EGR system, such as that of Fig. 4 and Fig. 9-12, the EGR passage 420 may be connected to the intake manifold 422. The intake manifold 422 may be an integrated intake manifold 422. The intake manifold 422 directs intake gases from the intake tract 122 to each of the combustion chambers 118 (in Fig. 4 (not shown). The EGR system includes an EGR cooler 424 for cooling exhaust gases recirculated to the intake manifold 422. Specifically, the EGR cooler 424 may be positioned upstream of the EGR passage 420 to cool the exhaust gases en route to the intake manifold 422.

[0053] With reference now to Fig. 6 shows this one side cross-sectional view 600 of the engine system 10 on the second side 112 of the engine system 10. Thus, the Fig. 6, the cross-section of the engine system 10 is taken along a plane parallel to the plane defined by the vertical axis 152 and the longitudinal axis 156. Internal components of the engine system 10 are located in Fig. 6 on the second side 112 of the motor system 10 free (are e.g. in Fig. 6 shown).

[0054] As in Fig. 6, the water pump pulley 138 may be positioned in front of (e.g., in the negative direction of the longitudinal axis 156 of the crankshaft sprocket 402) the crankshaft sprocket 402, the oil pump belt 405, the oil pump pulley 403, etc. Further, the oil pump belt 405 and the oil pump pulley 403 may be positioned in front of and adjacent to the crankshaft sprocket 402. Thus, the crankshaft sprocket 402 may be positioned behind the oil pump belt 405, the oil pump pulley 403, and the water pump pulley 138. However, the crankshaft sprocket 402, the idler gear 406, and the fuel pump drive gear 412 may be aligned with each other along the longitudinal axis 156. Thus, the crankshaft gear 402, the idler gear 406, and the fuel pump drive gear 412 can be positioned parallel to each other along a same plane, which plane can be parallel to a plane defined by the vertical axis 152 and the transverse axis 154.The rotational axes of the fuel pump drive gear 412, the crankshaft gear 402, and the idler gear 406 may thus be parallel to each other (e.g., may extend in the same direction). By positioning the gears 402, 412, and 406 in the same plane, the length of the engine system 10 with respect to the longitudinal axis 156 may be reduced relative to systems in which the pump 416 is driven by a belt or chain. Thus, the size, packaging, and / or cost of the engine system 10 may be reduced.

[0055] As in Fig. 6, the fuel pump drive gear 412 and the fuel pump 416 may be positioned vertically above the crankshaft 132. Additionally or alternatively, the fuel pump 416 may be positioned behind the first end 133 of the crankshaft 132 and / or behind the crankshaft gear 402, the idler gear 406, and the fuel pump drive gear 412. Furthermore, the fuel pump 416 may be positioned below the intake manifold 422 (with reference to Fig. 4 and described above) and positioned below the camshaft pulleys 142 and 144. The fuel pump 416 may be positioned below the EGR cooler 424.

[0056] As in Fig. 6, the tension roller 408 (in Fig. 6 by the camshaft drive belt 146 positioned above the tension pulley 408), the oil pump pulley 403, the oil pump belt 405, and the camshaft drive belt 146 at the front end 102 of the engine system 10 are all aligned along a same plane. Thus, the tension pulley 408, the oil pump pulley 403, the oil pump belt 405, and the camshaft drive belt 146 can be positioned parallel to one another along the same plane, which plane is parallel to a plane defined by the vertical axis 152 and the transverse axis 154. In other words, the tension pulley 408, the oil pump pulley 403, the oil pump belt 405, and the camshaft drive belt 146 can be positioned at a same position along the longitudinal axis 156. Furthermore, the rotational axes of the tension pulley 408, the oil pump pulley 403, the oil pump belt 405 and the camshaft drive belt 146 may be parallel to each other.

[0057] Fig. 6 also shows two of the pistons 202 connected to the crankshaft 132 via respective connecting rods 604. The crankshaft 132 may include main bearings 602 and counterweights 606. The counterweights 606 may reduce a magnitude of one or more vibration modes of the crankshaft 132 (e.g., movements of the crankshaft 132 in different directions, at different frequencies, etc.) when the rotational motion of the crankshaft 132 is converted into linear motion of the pistons 202.

[0058] With reference now to Fig. 7 and Fig. 8 show these perspective side views 700 and 800 respectively of the front end 102 of the engine system 10. Fig. 7 and Fig. 8 thus show the components at the front end 102 of the engine system 10, which is already shown in Fig. 4 and Fig. 5, with the front cover 141 removed, exposing internal components of the engine system 10 at the front end 102. Thus, Fig. 7 and Fig. 8 are described together in this description.

[0059] As in Fig. 8, the camshaft pulleys 142 and 144 may be positioned vertically above the fuel pump 416, the idler gear assembly 404, the tensioner 410, the fuel pump drive gear 412, and / or the crankshaft 132. Further, the tensioner pulley, the oil pump pulley 403, the oil pump belt 405, the camshaft drive belt 146, and the camshaft pulleys 142 and 144 are all arranged in a common plane at the front end 102 of the engine system 10. Thus, the tensioner pulley 408, the oil pump pulley 403, the oil pump belt 405, the camshaft drive belt 146, and the camshaft pulleys 142 and 144 can be positioned along a same plane parallel to one another, which plane can be parallel to a plane defined by the vertical axis 152 and the transverse axis 154.In other words, the tensioner pulley 408, the oil pump pulley 403, the oil pump belt 405, the camshaft drive belt 146, and the camshaft pulleys 142 and 144 may be positioned at the same position along the longitudinal axis 156. Furthermore, the rotational axes of the tensioner pulley 408, the oil pump pulley 403, the oil pump belt 405, the camshaft drive belt 146, and the camshaft pulleys 142 and 144 may be parallel to each other.

[0060] The fuel pump 416 may further be positioned below the intake manifold 422. Compared to examples where the fuel pump 416 is connected to the crankshaft 132 via a belt or chain, by connecting the fuel pump 416 to the crankshaft 132 via a drive gear (e.g., the idler gear 406) in this manner, the distance between the fuel pump 416 and the crankshaft 132 may be reduced. Thus, the fuel pump 416 may be positioned below the camshaft pulleys 142 and 144 rather than above the pulleys 142 and 144, as may be the case in examples where the fuel pump 416 is driven by a pulley or belt. Compared to examples where the fuel pump 416 is driven by a belt, the height of the engine system 10 with respect to the vertical axis can thus be adjusted by driving the fuel pump 416 by means of a drive wheel (e.g.intermediate gear 406).

[0061] Fig. 9 shows a cross-sectional view of the cylinder head 114 and illustrates exhaust gases and engine coolant flowing through the cylinder head 114 toward an EGR assembly 900. The cylinder head 114 includes a plurality of passages formed within an interior of the cylinder head 114. Specifically, the cylinder head 114 includes an internal exhaust passage 902 for flowing exhaust gases to the EGR assembly 900 and an internal coolant passage 904 for flowing coolant to the EGR assembly 900.

[0062] The internal exhaust tract 902 receives exhaust gases (e.g., combusted fuel and air) from one or more cylinders 118 and directs the exhaust gases through the cylinder head 114 to the EGR assembly 900. In the embodiment described herein with reference to Fig. 1-18, the exhaust manifold 128 is an external exhaust manifold connected to the cylinder head 114 by fasteners (e.g., bolts) and configured to direct exhaust gases from a plurality of exhaust ports of the cylinders 118 to an external exhaust outlet 1702 (e.g., outside the interior of the cylinder head 114 and in Fig. 17) to flow.

[0063] The internal exhaust tract 902 may be connected to (e.g., formed integrally with) one or more of the exhaust ports internal to the cylinder head 114 such that a portion of exhaust gases flowing from the one or more exhaust ports does not flow through the exhaust manifold 128. Instead, the above-described portion of exhaust gases may flow through the internal exhaust tract 902 toward the EGR assembly 900, as shown by the example exhaust flow path 916. In this configuration, the internal exhaust tract 902 receives the portion of exhaust gases directly from the exhaust ports of the cylinders 118. In other examples, exhaust gases may instead flow into the internal exhaust tract 902 from one or more exhaust pipes of the exhaust manifold 128. In these examples, the inner exhaust tract 902 may form an exhaust inlet aperture (e.g., an opening) on an outer surface of the cylinder head 114 (e.g., outside the interior of the cylinder head 114).The exhaust inlet aperture may be connected to one or more exhaust pipes to allow exhaust gases from the exhaust pipes to flow through the exhaust inlet aperture and into the internal exhaust tract 902. In other examples, the exhaust manifold 128 may instead be an internal exhaust manifold (IEM) and may be entirely contained within (e.g., formed within) the interior of the cylinder head 114. Specifically, the pipes of the IEM may be formed by interior surfaces of the cylinder head 114 and may extend through the interior of the cylinder head 114 to connect to the exhaust ports of the cylinders 118. In these examples, the internal exhaust tract 902 may be connected to (e.g., formed therewith) one or more of the exhaust pipes to receive a portion of exhaust gases from one or more of the respective cylinders 118. In still other examples, the internal exhaust tract 902 (e.g.,via the exhaust pipes) take in exhaust gases directly from a combination of the exhaust ports and the exhaust manifold.

[0064] The EGR assembly 900 includes an EGR valve 905 positioned within an interior 952 of a body 950 of the EGR assembly 900 and within a flow path (e.g., exhaust flow path 916) of exhaust gases from the internal exhaust tract 902. The EGR valve 905 is positioned downstream of an EGR inlet 906 formed by an outer surface of the body 950, with the EGR inlet 906 of the body 950 directly connected to an EGR outlet 910 of the cylinder head 114. The EGR valve 905 may be a normally closed valve and may be moved to an open position, a closed position, and multiple positions between the open position and the closed position by means of a valve actuator (e.g., a solenoid, a hydraulic actuator, etc.). By adjusting an opening amount of the EGR valve 905, a flow rate of exhaust gases from the inner exhaust tract 902 through the EGR assembly 900 can be adjusted.For example, increasing the opening amount can increase the flow rate of exhaust gases, and decreasing the opening amount can decrease the flow rate of exhaust gases.

[0065] In one example, the position of the EGR valve 905 may be adjusted by an electronic control unit (e.g., a computer system) of the engine system 10. The control unit 10 receives signals from the various sensors of the engine system 10 and utilizes the various actuators of the engine system 10 to adjust engine operation based on the received signals and commands stored in a memory of the control unit. For example, adjusting an exhaust gas flow through the EGR valve 905 may include adjusting an actuator of the EGR valve 905 to adjust an opening amount of the EGR valve 905. In one example, the control unit may determine a control signal to be sent to the valve actuator, such as an amplitude of the signal determined based on a determination of the flow rate of exhaust gas through the EGR valve 905.The flow rate of exhaust gas through the EGR valve may be based on a measured flow rate or determined based on operating conditions such as engine speed and / or a position of the EGR valve 905. The controller may determine the amplitude through a determination that directly considers the flow rate, such as increasing the amplitude to increase the flow rate (e.g., increasing an opening amount of the EGR valve 905). Alternatively, the controller may determine the amplitude based on a calculation using a lookup table, where the input is the flow rate and the output is the signal amplitude.

[0066] The internal coolant passage 904 may be a coolant passage positioned parallel or in series with other coolant passages formed in the cylinder head 114 by interior surfaces of the cylinder head 114. Coolant (e.g., engine coolant) may flow within the cylinder head 114 through the internal coolant passage 904 and toward the EGR assembly 900, as shown by an example coolant flow path 914. The coolant flows from the internal coolant passage 904 through the body 950 of the EGR assembly 900 and into the EGR cooler 424. Exhaust gases and coolant do not mix or come together within the body 950 of the EGR assembly 900. The inner coolant passage 904 forms a coolant outlet 912 on an outer surface of the cylinder head 114, and the coolant outlet 912 is fluidly connected to a coolant inlet 908 of the EGR assembly 900. In the Fig. 9, the EGR assembly 900 is directly connected to the outer surface of the cylinder head 114 at the coolant outlet 912 and the EGR outlet 910, such that no additional coolant or exhaust passages are positioned outside the cylinder head 114 between the coolant outlet 912 and the coolant inlet 908 or between the EGR outlet 910 and the EGR inlet 906. By directly connecting the EGR assembly 900 to the cylinder head 114 and routing exhaust gases and coolant through the cylinder head to the EGR assembly 900, the number of coolant and / or exhaust passages outside the cylinder head 114 can be reduced and the size of the engine system 10 can be reduced.

[0067] The EGR assembly 900 is fluidly connected to the EGR cooler 424 such that coolant flowing into the EGR assembly 900 (e.g., via coolant flow path 914) is directed into coolant passages of the EGR cooler 424, and exhaust gas flowing into the EGR assembly 900 (e.g., via the exhaust flow path 916) is directed into a bypass passage and / or a collection volume of the EGR cooler 424, as described below with reference to Fig. 10-12 is described.

[0068] Fig. 10-12 show different views of the EGR cooler 424. In detail, Fig. 10 is a view of an outer side of the EGR cooler 424 (e.g., the outer surfaces formed by a body 1044 of the EGR cooler 424), Fig. 11 shows a view of the EGR cooler 424 along a first cross-sectional plane parallel to the vertical axis 152 and transverse axis 154 and positioned at an inlet end 1042 of the EGR cooler 424, and Fig. 12 shows a view of the EGR cooler 424 along a second cross-sectional plane parallel to the first cross-sectional plane and positioned at an outlet end 1040 of the EGR cooler 424. The inlet end 1042 and the outlet end 1040 are positioned opposite each other along a center axis 1030 of the EGR cooler 424. From the EGR assembly 900 connected to the cylinder head 114 (as described above with reference to Fig. 9), exhaust gases may flow into a collection volume 1100 formed by an interior space 1046 of the body 1044 via an exhaust inlet 1104 positioned at the inlet end 1042. The exhaust gases may be cooled by heat transfer (e.g., transfer of thermal energy) from the exhaust gases to the coolant (e.g., engine coolant) flowing through one or more coolant passages (not shown) surrounding a perimeter of the collection volume 1100. The coolant passages are formed in the interior space 1046 of the body 1044 and are fluidly separated from the collection volume 1100 such that coolant and exhaust gases do not mix and / or do not come together in the EGR cooler 424.

[0069] Coolant may flow into the coolant passages of the EGR cooler via one or more coolant inlets positioned at the inlet end 1042 of the EGR cooler 424. In the Fig. 10-12 and described herein, the inlet end 1042 includes a first coolant inlet 1002, a second coolant inlet 1004, and a third coolant inlet 1006 positioned radially about the center axis 1030 and the exterior of the EGR cooler 424. The coolant inlets (e.g., first coolant inlet 1002, second coolant inlet 1004, and third coolant inlet 1006) are fluidly connected to the internal coolant passage 904 of the cylinder head 114 via the EGR assembly 900. The first coolant inlet 1002 is formed as an opening in a first flange 1008 of the body 1044, the second coolant inlet 1004 is formed as an opening in a second flange 1010 of the body 1044 and the third coolant inlet 1006 is formed as an opening in a third flange 1012 of the body 1044.The first flange 1008, the second flange 1010 and the third flange 1012 are each directly connected to the EGR assembly 900 by means of a plurality of fasteners 1014 (e.g., bolts), such that the first coolant inlet 1002, the second coolant inlet 1004 and the third coolant inlet 1006 are fluidly connected to corresponding coolant outlets of the EGR assembly 900.

[0070] In one example, coolant flows from the internal coolant passage 904 of the cylinder head 114 into the EGR assembly 900 and into the coolant passages of the EGR cooler 424 via the coolant inlets described above. The coolant may absorb thermal energy from exhaust gases in the EGR cooler 424 and may then flow out of the EGR cooler 424 via a coolant outlet 1022 to be recirculated within the engine system 10 (e.g., cooled by a radiator fluidly connected to the coolant outlet 1022 and / or pumped back into the cylinder head 114). In one example, coolant flowing out of the EGR cooler 424 via the coolant outlet 1022 may be directed to a heater core via one or more external coolant passages. Due to the direct connection of the coolant inlets (e.g.,Due to the connection of the first coolant inlet 1002, the second coolant inlet 1004, and the third coolant inlet 1006 to the body 950 of the EGR assembly 900, passages connected to the coolant outlet 1022 are the only external coolant passages included in the engine system 10. By reducing the number of external coolant passages, an overall size of the engine system 10 can be reduced.

[0071] The EGR cooler 424 includes a bypass passage 1102 configured to direct exhaust gases through the EGR cooler 424 and reduce an amount of thermal energy transferred from the exhaust gases to the coolant flowing through the coolant passages. The bypass passage 1102 extends within the interior 1046 of the EGR cooler 424 from the inlet end 1042 to the outlet end 1040 and is positioned away from the coolant passages of the EGR cooler 424. With this configuration, an amount of heat transferred to the coolant from exhaust gas flowing through the bypass passage 1102 can be reduced relative to an amount of heat transferred to the coolant via exhaust gas flowing within the collection volume 1100.

[0072] Exhaust gases flowing through the collection volume 1100 may flow out of the EGR cooler 424 via a first exhaust outlet 1016 and / or a second exhaust outlet 1020. The first exhaust outlet 1016 and / or the second exhaust outlet 1020 may each be fluidly connected to the intake manifold 422 (e.g., via EGR passage 420 connected to the first exhaust outlet 1016) to mix exhaust gases from the EGR cooler 424 with intake air flowing into the intake manifold 422 for delivery to the cylinders 118. Additionally, exhaust gases flowing through the bypass passage 1102 may flow out of the first exhaust outlet 1016. However, to direct a flow of exhaust gases from the bypass passage 1102 to the first exhaust outlet 1016, the EGR cooler 424 includes a baffle 1200 surrounding a periphery of the first exhaust outlet 1016 within the interior 1046 of the body 1044 of the EGR cooler 424.The baffle 1200 forms a partially enclosed volume that is fluidly connected to both the bypass passage 1102 and the collection volume 1100 and is shaped to direct exhaust gases from the bypass passage 1102 toward the first exhaust outlet 1016. By directing the exhaust gases in this manner via the baffle 1200, an amount of exhaust gas recirculating from the bypass passage 1102 into the collection volume 1100 can be reduced.

[0073] Fig. 13-14 show different cross-sectional views of several intake manifolds included in the intake manifold 422. In detail, Fig. 13 is a cross-sectional view of the intake manifold 422 illustrating relative positioning of spiral intake manifolds and non-spiral intake manifolds of the intake manifold 422, and Fig. 14 shows a cross-sectional view of the intake manifolds connected to intake ports of two cylinders 118 of the engine system 10. A main intake inlet 1316 of the intake manifold 422 is positioned along a center axis 1390 of the intake manifold 422 and is fluidly connected to each of the intake manifolds.

[0074] Fig. 13 shows a relative positioning of cylinders 118 in the inline 4 arrangement of the engine system 10. For example, a first cylinder 1350 and a fourth cylinder 1356 may be referred to herein as outer cylinders or flanking cylinders, and a second cylinder 1352 and a third cylinder 1354 may be referred to herein as inner cylinders, with the inner cylinders positioned along an axis 1318 between each of the outer cylinders. Fig. 14 shows an enlarged view of the inner cylinders (e.g., the second cylinder 1352 and the third cylinder 1354).

[0075] The intake manifold 422 included in the engine system 10 is an integrated intake manifold with intake tubes (e.g., intake ports) formed by interior surfaces of the cylinder head 114. The intake tubes include both helical and non-helical intake tubes positioned in alternating arrangements relative to the cylinders 118. For example, the first cylinder 1350 is connected to a first non-helical tube 1300 and a first helical tube 1302, the second cylinder 1352 is connected to a second non-helical tube 1304 and a second helical tube 1306, the third cylinder 1354 is connected to a third helical tube and a third non-helical tube 1310, and the fourth cylinder 1356 is connected to a fourth helical tube 1312 and a fourth non-helical tube 1314.

[0076] In this arrangement, the tubes connected to the first cylinder 1350 and the second cylinder 1352 are in an antisymmetrical arrangement relative to the tubes connected to the third cylinder 1354 and the fourth cylinder 1356. Specifically, the tubes connected to the first cylinder 1350 and the second cylinder 1352 form a first tube group 1370, and the tubes connected to the third cylinder 1354 and the fourth cylinder 1356 form a second tube group 1372, with the tubes of the first tube group 1370 being positioned in an opposite arrangement relative to the tubes of the second tube group 1372. In outward directions (e.g., radial directions) from the central axis 1390, for example, the first tube group 1370 and the second tube group 1372 each include helical tubes positioned adjacent to the central axis 1390 (e.g., the second helical tube 1306 and the second helical tube 1308, respectively).the third spiral tube 1308), followed first in the outward directions by non-spiral tubes (e.g., 1304 and 1310, respectively), followed second in the outward directions by spiral tubes (e.g., 1302 and 1312, respectively), and followed third in the outward directions by non-spiral tubes (1300 and 1314, respectively). In embodiments where the engine includes a different number and / or arrangement of cylinders, the intake manifolds are arranged in a similar arrangement (e.g., the first tube group being positioned across the center axis of the second tube group and having an opposite arrangement of tubes relative to the second tube group).

[0077] The spiral tubes (e.g., 1302, 1306, 1308, and 1312) are shaped such that an amount of swirl (e.g., turbulence) of intake air flowing through the spiral tubes toward the corresponding connected cylinders 118 is increased by an amount greater than the non-spiral tubes (e.g., 1300, 1304, 1310, 1314). In one example, the spiral tubes may be formed with a spiral shape (e.g., may be formed as passages that wrap around a direction of airflow through the passages), and the non-spiral tubes may be formed with a relatively cylindrical shape (e.g., smooth and non-twisting). In other examples, the spiral tubes and / or non-spiral tubes may have a different type of shape.However, in each example, the spiral tubes are shaped to increase the amount of swirl of the intake air by a greater amount than with non-spiral tubes. In this way, when fuel is injected into the cylinders 118 by the fuel injectors 124, the amount of mixing of fuel and intake air in the cylinders 118 can be increased, thereby increasing the combustion efficiency of the fuel and intake air in the cylinders 118 (e.g., reducing the amount of unburned fuel / intake air in the cylinders 118).

[0078] Fig. 14 shows an enlarged view of the second cylinder 1352 and the third cylinder 1354, showing a relative arrangement of intake ports, exhaust ports, and glow plugs connected to the cylinders 1352 and 1354. For example, the second cylinder 1352 includes exhaust ports 1408 and 1410, intake ports 1430 and 1432, and a glow plug 1404. The third cylinder 1354 includes exhaust ports 1412 and 1414, intake ports 1434 and 1436, and a glow plug 1406. The intake port 1430 and the intake port 1432 of the second cylinder 1352 are connected (respectively) to the second non-helical tube 1304 and the second helical tube 1306 of the first tube group 1370. The inlet port 1434 and the inlet port 1436 are connected to a third spiral tube 1308 and (respectively) a third non-spiral tube 1310 of the second tube group 1372.The glow plug 1404 connected to the second cylinder 1352 extends from the cylinder head 114 at a midpoint of the second cylinder 1352 downward into the second cylinder 1352. Similarly, the glow plug 1406 connected to the third cylinder 1354 extends from the cylinder head 114 at a midpoint of the third cylinder 1354 downward into the third cylinder 1354. Other cylinders included in the engine system 10 include a similar glow plug arrangement (e.g., the first cylinder 1350 and the fourth cylinder 1356).

[0079] To reduce a likelihood of fuel injected by the fuel injectors 124 hitting the glow plugs (e.g., glow plugs 1404 and 1406), and to enable the alternating arrangement of the intake manifolds and the increased amount of intake air swirl as described above, the fuel injectors 124 may be positioned relative to each other at different angles (e.g., with different spray patterns and / or directions), as described below with reference to Fig. 15-16 is described.

[0080] Fig. 15 shows a view of two exemplary fuel injectors connected to the engine system 10, and Fig. Figure 16 shows a relative arrangement of the fuel injectors 124, with the engine system 10 omitted for illustration purposes. The position of each fuel injector is determined by the Fig. 13-16 shown axis 1318.

[0081] A first fuel injector 1616 includes a solenoid valve 1612 and is fluidly connected to a fuel line 1504, a fuel return line 1608, and the first cylinder 1350. A second fuel injector 1500 includes a solenoid valve 1508 and is fluidly connected to the fuel line 1504, a fuel return line 1512, and the second cylinder 1352. A third fuel injector 1502 includes a solenoid valve 1510 and is fluidly connected to the fuel line 1506, the fuel return line 1514, and the third cylinder 1354. A fourth fuel injector 1618 includes a solenoid valve 1614 and is fluidly connected to the fuel line 1506, the fuel return line 1610, and the fourth cylinder 1356. Each fuel injector is shown with a corresponding axis positioned parallel to a direction of fuel flow from the corresponding fuel injector solenoid valve into the fuel injector.For example, the first fuel injector 1616 is positioned along an axis 1604, the second fuel injector 1500 is positioned along an axis 1520, the third fuel injector 1502 is positioned along the axis 1522, and the fourth fuel injector 1618 is positioned along the axis 1606. The axis 1604 is at a first angle 1600 relative to axis 1318, axis 1520 is at a second angle 1516 relative to axis 1318, axis 1522 is at a third angle 1518 relative to axis 1318, and axis 1606 is at a fourth angle 1602 relative to axis 1318.

[0082] The first angle 1600, the second angle 1516, the third angle 1518, and the fourth angle 1602 may each be a different angle amount, such that the first fuel injector 1616, the second fuel injector 1500, the third fuel injector 1502, and the fourth fuel injector 1618 each inject fuel into their respective connected cylinders at different angles. For example, an amount and / or direction of swirl of intake air flowing into the first cylinder 1350 may be different due to the arrangement of the intake manifolds, as described above with reference to Fig. 13-14, may be different than an amount and / or direction of swirl of intake air flowing into the second cylinder 1352. As a result, the second angle 1516 of the second fuel injector 1500 may be a different angular amount than the first angle 1600 of the first fuel injector 1616, such that a fuel spray pattern and / or fuel spray angle of the second fuel injector 1500 is different than a fuel spray pattern and / or fuel spray angle of the first fuel injector 1616. In this way, each fuel injector may be angled separately to achieve relatively uniform combustion efficiency for each of the cylinders 118. In other examples, one or more of the angles of the fuel injectors may have a same angular amount, with at least one fuel injector having a different angular amount.

[0083] Fig. 17 shows a view of the exhaust manifold 128 connected to the cylinder head 114 of the engine system 10. A sealing portion 1710 of a gasket 1700 is positioned at an interface between the cylinder head 114 and the exhaust manifold 128 and fluidly seals the interface between the cylinder head 114 and the exhaust manifold 128 (e.g., prevents leakage of exhaust gas, oil, etc. from the location where the exhaust manifold connects to the cylinder head 114). The gasket 1700 may include a plurality of apertures shaped to align with the exhaust ports of the cylinder head 114 and may allow exhaust gases to flow from the exhaust ports into exhaust pipes (e.g., passages) of the exhaust manifold 128.

[0084] The gasket 1700 additionally includes a heat-shielding portion 1712 having an upper surface 1706, a lower surface 1707, and a plurality of fluid channels 1704 extending from the upper surface 1706 to the lower surface 1707. During conditions where the gasket 1700 is connected between the cylinder head 114 and the exhaust manifold 128, the fluid channels 1704 are positioned vertically in series (e.g., in a direction from the upper surface 1706 to the lower surface 1707) with the direction of gravity. Fluid (e.g., oil) impinging on the gasket 1700 from locations external to the exhaust manifold 128 (e.g., locations vertically above the gasket 1700) may be prevented by the gasket 1700 from leaking onto the exhaust manifold 128 and may instead flow into one or more of the fluid channels 1704. The fluid channels 1704 may direct the fluid away from the exhaust manifold 128, thereby reducing a likelihood of degradation of the exhaust manifold 128.Additionally, the heat-shielding portion 1712 may be formed from a material that is resistant to degradation at typical engine operating temperatures (e.g., steel, fiberglass, etc.) and may be configured to conduct heat from the engine system 10 away from the exhaust manifold 128. In this way, a likelihood of degradation of the exhaust manifold 128 may be further reduced.

[0085] Fig.18 shows an enlarged view of the fuel pump 416 described above. The fuel pump 416 is directly driven by the fuel pump drive gear 412, with the fuel pump drive gear 412 meshing with the idler gear 406. The fuel pump drive gear 412 includes a first sprocket 1818 fixedly connected to a first bearing 1820 and a second sprocket 1808 rotatably connected to the first bearing 1820. The second sprocket 1808 may normally be non-rotatable relative to the first bearing 1820. However, an operator of the engine system 10 (e.g., a user) may rotate the second sprocket 1808 relative to the first bearing 1820 and the first sprocket 1818 by rotating a first adjustment pin 1830 of the fuel pump drive gear 412. By rotating the second toothed disk 1808 relative to the first bearing 1820 by means of the first adjusting pin 1830 (e.g.in the direction 1850), a position of teeth of the second toothed disk 1808 relative to teeth of the intermediate gear 406 can be adjusted (as further described below).

[0086] The idler gear 406 includes a third toothed disk 1814 fixedly connected to a second bearing 1834, and a fourth toothed disk 1817 rotatably connected to the second bearing 1834. The fourth toothed disk 1817 may normally be rotationally fixed relative to the second bearing 1834. However, the operator of the motor system 10 may rotate the fourth toothed disk 1817 relative to the second bearing 1834 and the third toothed disk 1814 by turning a second adjusting screw 1836 of the idler gear 406. By rotating the fourth toothed disk 1817 relative to the second bearing 1834 by means of the second adjusting pin 1836 (e.g., in direction 1850), a position of teeth of the fourth toothed disk 1817 relative to teeth of the third toothed disk 1814 can be adjusted.

[0087] In the configuration described above, the first sprocket 1818 is in meshing engagement with the third sprocket 1814, and the second sprocket 1808 is in meshing engagement with the fourth sprocket 1817. The first inset 1800 shows an exemplary engagement of the fuel pump drive gear 412 with the idler gear 406. In this example, the teeth of the fourth sprocket 1817 are shown in a first position relative to teeth of the third sprocket 1814. The fourth sprocket 1817 can be rotated to a second position shown by a second inset 1802 by rotating the first adjustment pin 1830 to move the teeth of the fourth sprocket 1817 in a direction 1844 relative to the teeth of the third sprocket 1814.Moving the fourth sprocket 1817 to the second position shown by the second sub-image 1802 reduces a gap amount between the teeth of the fourth sprocket 1817 and the teeth of the second sprocket 1808. By reducing the gap amount between the teeth as described above, a vibration amount of the idler gear 406 and / or the fuel pump drive gear 412 can be reduced. By reducing the vibration amount of the gears, degradation of the fuel pump 416 can be reduced and engine torque transmission to the fuel pump 416 can be increased.

[0088] In this way, by driving a fuel pump using a series of gears that transmit torque from a crankshaft to the fuel pump, a technical effect of reducing lateral load on a fuel pump can be achieved. Furthermore, compared to systems that use belts and pulleys to connect the crankshaft to the fuel pump, friction losses occurring between the fuel pump and the crankshaft can be reduced. By driving the fuel pump with the series of gears instead of belts or chains, a further technical effect of reducing the distance between the crankshaft and the fuel pump can be achieved, thereby reducing the size, packaging space, and cost of the engine system.

[0089] By connecting a camshaft drive belt to an idler gear driven by a crankshaft sprocket, which has a larger diameter than the crankshaft sprocket, a further technical effect of reducing engine size and improving compactness can be achieved. Since the idler gear can rotate at a slower speed than the crankshaft, the size of the camshaft pulleys can be reduced, thereby reducing the overall size, packaging space, and cost of the engine system relative to systems where the camshaft belt is directly connected to the crankshaft. The size, packaging space, and cost of the engine system can be further reduced by arranging the crankshaft sprocket, the idler gear, and the fuel pump drive gear parallel to each other along the same plane.By positioning the wheels in the same plane, the length of the motor system can be reduced relative to systems where the pump is driven by a belt or chain.

[0090] In one embodiment, a front end of an engine comprises: a first end of a crankshaft; an idler gear assembly including an idler gear and an idler pulley, the idler gear meshing with the first end of the crankshaft and the idler pulley connected to and sharing a common axis of rotation with the idler gear; first and second camshaft pulleys positioned vertically above the idler gear assembly; and a cam drive belt contacting the first and second camshaft pulleys and the idler pulley, respectively. A second example of the front end optionally includes the first example and further includes the cam drive belt not contacting the crankshaft.A third example of the front end optionally includes the first and / or second example and further includes the front end of the engine being disposed opposite a rear end of the engine, the rear end including a flywheel connected to a second end of the crankshaft. A fourth example of the front end optionally includes one or more or each of the first through third examples and further includes the first and second camshaft pulleys having a same diameter and being positioned adjacent to each other on an upper side of the front end of the engine relative to a vertical axis of the engine, the upper side being disposed opposite a lower side of the engine, the lower side including an oil pan.A fifth example of the front end optionally includes one or more or each of the first through fourth examples, and further includes the tension pulley having a smaller diameter than the idler gear, and the cam drive belt contacting an outer peripheral surface of the tension pulley. A sixth example of the front end optionally includes one or more or each of the first through fifth examples, and further includes the first end of the crankshaft rotating in a first direction, the idler gear assembly rotating in a second direction opposite the first direction, and the first and second camshaft pulleys rotating in the second direction.A seventh example of the front end optionally includes one or more or each of the first through sixth examples and further includes a first end of a first camshaft being directly connected to the first camshaft pulley and a second end of a second camshaft being directly connected to the second camshaft pulley, wherein the first and second camshafts rotate in a direction opposite a rotational direction of the first end of the crankshaft. An eighth example of the front end optionally includes one or more or each of the first through seventh examples and further includes the idler gear having 63 teeth, the first end of the crankshaft having 45 teeth, and each of the first and second camshaft pulleys having 21 teeth.A ninth example of the front end optionally includes one or more or each of the first through eighth examples and further includes an oil pump drive gear drivingly connected to the first end of the crankshaft by an oil pump drive belt, wherein the oil pump drive belt, the oil pump drive gear, the cam drive belt, and the first and second camshaft pulleys are all disposed in a same plane at the front end of the engine. A tenth example of the front end optionally includes one or more or each of the first through ninth examples and further includes a fuel pump drive gear in meshing engagement with the idler gear, wherein the fuel pump drive gear is directly connected to a drive shaft of a fuel pump.

[0091] In one embodiment, a method for an engine comprises: transmitting rotational motion from a crankshaft to an idler gear, the idler gear meshing with a first end of the crankshaft by means of a plurality of intermeshing teeth; rotating an idler pulley directly connected to the idler gear by means of rotation of the idler gear, the idler gear and the idler pulley having a common axis of rotation; and driving rotation of the first and second camshaft pulleys by a cam drive belt driven by the idler pulley, the cam drive belt contacting an outer surface of the first and second camshaft pulleys and the idler pulley.In a first example of the method, transferring rotational motion from the crankshaft to the idler gear comprises rotating the crankshaft in a first direction and rotating the idler gear in a second direction opposite the first direction, and rotating the idler gear comprises rotating the tension pulley in the second direction. A second example of the method optionally includes the first example and further comprises rotating a first camshaft directly connected to the first camshaft pulley in the second direction and rotating a second camshaft directly connected to the second camshaft pulley in the second direction.A third example of the method optionally includes one or both of the first and second examples, and further includes where driving rotation of the first and second camshaft pulleys includes rotating the first and second camshaft pulleys at half a camshaft speed. A fourth example of the method optionally includes one or more or each of the first to third examples, and further includes where the idler gear, the tensioner pulley, and the first and second camshaft pulleys are all disposed at a front end of the engine, the front end being opposite a rear end of the engine that includes a flywheel of the engine.

[0092] In one embodiment, a system for an engine comprises: a front end comprising: a first end of a crankshaft; an idler gear assembly including an idler gear and an idler pulley, the idler gear meshing with the first end of the crankshaft and the idler pulley connected to the idler gear and having a common axis of rotation therewith; first and second camshaft pulleys connected to first and second camshafts, respectively; and a cam drive belt contacting each of the first and second camshaft pulleys and the idler pulley and not contacting the first end of the crankshaft; and a rearward end disposed opposite the front end, the rearward end including a flywheel connected to a second end of the crankshaft.In a first example of the system, the tensioner pulley has a smaller diameter than the idler gear, and the idler gear includes a greater number of teeth than the first end of the crankshaft. A second example of the system optionally further includes the first example wherein the front end includes a fuel pump drive gear in meshing engagement with the idler gear, the fuel pump drive gear being directly connected to a drive shaft of a fuel pump, the fuel pump being positioned further inboard of the engine compared to the front end of the engine.A third example of the system optionally includes one or both of the first and second examples and further includes the front end further comprising an oil pump drive gear in meshing engagement with a crankshaft pulley directly connected to the first end of the crankshaft and directly connected to a drive shaft of an oil pump, wherein an oil pump belt is engaged with both the crankshaft pulley and the oil pump drive gear.A fourth example of the system optionally includes one or more or each of the first to third examples and further includes wherein the front end further includes a tensioning device positioned vertically above the idler gear assembly and vertically below the first and second camshaft pulleys, wherein a side of the tensioner abuts an outer surface of the cam drive belt and wherein an inner surface of the cam drive belt abuts the first and second camshaft pulleys.

[0093] In another embodiment, a system comprises: a cylinder head of an engine; a plurality of passages extending through an interior of the cylinder head and formed by interior surfaces of the cylinder head, the plurality of passages including a first passage forming an exhaust outlet on an exterior surface of the cylinder head and a second passage forming a coolant outlet on the exterior surface; and an EGR valve assembly directly connected to the cylinder head at the exhaust outlet and the coolant outlet. In a first example of the system, the EGR valve assembly includes a coolant passage directly connected to the second passage, and wherein engine coolant is configured to flow from the second passage in the cylinder head to the coolant passage of the EGR valve assembly.

[0094] In yet another embodiment, an EGR cooler comprises: a body having an inlet end and an outlet end; an exhaust gas collection volume positioned within an interior of the body and fluidly connected to an exhaust outlet formed through an outer surface of the body at the outlet end; a baffle having a first end shaped to enclose a perimeter of the exhaust outlet within the interior; and an exhaust gas bypass passage extending through the interior of the body from the inlet end of the body to the baffle at a second end of the baffle opposite the first end. In a first example of the EGR cooler, the EGR cooler further comprises an exhaust outlet positioned at the outlet end, the exhaust outlet fluidly connected to the baffle.

[0095] In yet another embodiment, a system comprises: an intake manifold having: a first end positioned opposite a second end; a main intake aperture positioned midway between the first end and the second end along a central axis; a first intake manifold positioned between the central axis and the first end; a second intake manifold positioned adjacent to the first intake manifold and between the central axis and the second end; a third intake manifold positioned adjacent to the first intake manifold between the first end and the first intake manifold; and a fourth intake manifold positioned adjacent to the second intake manifold between the second end and the second intake manifold; wherein the first intake manifold and the second intake manifold are each helical passages, and wherein the third intake manifold and the fourth intake manifold are each non-helical passages.

[0096] In yet another embodiment, a system comprises: a cylinder bank having a plurality of first and second engine cylinders; an intake manifold having a plurality of helical intake manifolds positioned in alternating arrangement with a plurality of non-helical intake manifolds; a plurality of first fuel injectors connected to the plurality of first engine cylinders and angled in a first direction relative to a centerline of the cylinder bank; and a plurality of second fuel injectors connected to the plurality of second engine cylinders and angled in a second direction opposite the first direction relative to the centerline.

[0097] In yet another embodiment, a system for an intake manifold of an engine comprises: four engine cylinders arranged in an in-line configuration; a main intake inlet fluidly connected to each of the four engine cylinders and centered along a central axis of the intake manifold, two cylinders of the four engine cylinders being symmetrically arranged on opposite sides of the central axis; a plurality of helical intake manifolds, each of the four engine cylinders being fluidly connected to the main intake inlet by one of the plurality of helical intake manifolds; and a plurality of non-helical intake manifolds, each of the four engine cylinders being fluidly connected to the main intake inlet by one of the plurality of non-helical intake manifolds, and wherein the plurality of helical intake manifolds and the plurality of non-helical intake manifolds have mirror symmetry about the central axis.In a first example of the intake manifold system, the system further comprises a plurality of fuel injectors, wherein each fuel injector of the plurality of fuel injectors is connected to a different one of the four engine cylinders and is arranged at a different angle than other fuel injectors of the plurality of fuel injectors. In a second example of the intake manifold system, the different angle of each of the fuel injectors is based on a geometry of a corresponding helical intake manifold of the corresponding engine cylinder.

[0098] In yet another embodiment, an exhaust manifold gasket comprises: a sealing portion shaped to fluidly seal a mating interface between an exhaust manifold and a cylinder head; and a heat-shielding portion having an upper surface, a lower surface, and a plurality of fluid channels converging from the upper surface to the lower surface, the fluid channels being positioned vertically above the sealing portion relative to a direction of gravity at the mating interface.

[0099] In yet another embodiment, a system comprises: a fuel pump; a fuel pump drive gear assembly connected to the fuel pump, comprising a first drive gear fixedly connected to a first bearing and a second drive gear rotatably connected to the first bearing and rotatable relative to the first bearing by means of a first adjustment pin; and an idler gear assembly having a first idler gear fixedly connected to a second bearing and a second idler gear rotatably connected to the second bearing and rotatable relative to the second bearing by means of a second adjustment pin, the first idler gear in meshing engagement with the first drive gear and the second idler gear in meshing engagement with the second drive gear.

[0100] It should be noted that the example control and estimation routines contained herein may be utilized with various engine and / or vehicle system configurations. The control methods and routines disclosed herein may be stored as executable instructions in non-transitory memory and executed by the control system, including the controller combined with the various sensors, actuators, and other engine hardware. The particular routines described herein may represent one or more of a number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like. Thus, various steps, operations, and / or functions shown may be performed in the sequence shown, in parallel, or in some cases skipped.Similarly, the order of processing is not necessarily required to achieve the features and advantages of the exemplary embodiments described herein, but is provided for ease of illustration and description. Depending on the particular strategy employed, one or more of the illustrated steps, operations, and / or functions may be performed repeatedly. Further, the described steps, operations, and / or functions may graphically represent code to be programmed into non-volatile memory of the machine-readable storage medium in the engine control system, wherein the described steps are performed by executing the instructions in a system including the various engine hardware components combined with the electronic control unit.

[0101] It should be understood that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not intended to be limiting, as numerous modifications are possible. For example, the foregoing technology may be employed in V-6, I-4, I-6, V-12, horizontally opposed 4-cylinder, and other engine types. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, as well as other features, functions, and / or characteristics disclosed herein.

[0102] The claims may refer to "a" element or "a first" element, or the equivalent thereof. Such claims should be construed as encompassing the inclusion of one or more such elements, neither requiring nor excluding two or more such elements.

Claims

[1] Front end of an engine, comprising: a first end of a crankshaft (132); an idler gear assembly (404) comprising an idler gear (406) and a tensioner pulley (408), the idler gear (406) being in meshing engagement with the first end of the crankshaft (132) and the tensioner pulley (408) being connected to the idler gear (406) and having a common axis of rotation therewith; first and second camshaft pulleys (142, 144) positioned vertically above the idler gear assembly (404); a cam drive belt (146) contacting the first and second camshaft pulleys (142, 144) and the tension pulley (408), respectively; and a fuel pump drive gear in direct meshing engagement with the idler gear, wherein the fuel pump drive gear (412) is directly connected to a drive shaft (415) of a fuel pump (416), the fuel pump (416) being positioned in a direction of the rotational axis of the idler gear between pistons of the engine and the idler gear (406) and the fuel pump drive gear (412). [2] A front end according to claim 1, wherein the cam drive belt (146) does not contact the crankshaft (132) and wherein the tension pulley (408) is disposed forward of the idler gear (406), closer to a front cover (141) of the front end than the idler gear. [3] The front end of claim 2, further comprising an oil pump drive gear (403) drivingly connected to the first end of the crankshaft (132) by an oil pump drive belt (146), the oil pump drive belt (146), the oil pump drive gear (403), the cam drive belt (146), the first and second camshaft pulleys (142, 144), and the tensioner pulley (408) all being disposed in a same plane at the front end of the engine. [4] The front end of claim 1, wherein the front end of the engine is disposed opposite a rear end of the engine, the rear end including a flywheel (134) connected to a second end of the crankshaft (132), the cylinders (118) of the engine being positioned in an in-line configuration with one of the pistons positioned within each cylinder (118), and the fuel pump (416) being positioned in front of all the pistons of the engine in the direction of the axis of rotation and relative to the front end. [5] The front end of claim 1, wherein the first and second camshaft pulleys (142, 144) have a same diameter and are positioned adjacent to each other relative to a vertical axis of the engine at a top surface of the front end of the engine, the top surface being opposite a bottom surface of the engine, the bottom surface including an oil pan (120), and the engine is a diesel engine. [6] The front end of claim 1, wherein the tension pulley (408) has a smaller diameter than the idler gear (406) and wherein the cam drive belt (146) contacts an outer peripheral surface of the tension pulley (408). [7] The front end of claim 1, wherein the first end (133) of the crankshaft (132) rotates in a first direction, the idler gear assembly (404) rotates in a second direction opposite the first direction, and the first and second camshaft pulleys (142, 144) rotate in the second direction, and wherein the fuel pump drive gear in direct meshing engagement with the idler gear (406) includes teeth of the fuel pump drive gear (416) in meshing engagement with teeth of the idler gear. [8] The front end of claim 1, further comprising a first end of a first camshaft directly connected to the first camshaft pulley and a second end of a second camshaft directly connected to the second camshaft pulley, the first and second camshafts rotating in a direction opposite to a direction of rotation of the first end of the crankshaft (132). [9] The front end of claim 1, wherein the idler gear (406) has 63 teeth, the first end (133) of the crankshaft (132) has 45 teeth, and the first and second camshaft pulleys (142, 144) each have 21 teeth. [10] The front end of claim 1, wherein the fuel pump (416) is a diesel fuel injection pump and is disposed vertically above the crankshaft (132) and vertically below an EGR cooler (424). [11] A method for an engine, comprising: Transmitting a rotary motion from a crankshaft (132) to an intermediate gear, wherein the intermediate gear (406) meshes with a first end of the crankshaft (132) by means of a plurality of intermeshing teeth; Rotating a tensioning roller (408) which is directly connected to the intermediate wheel (406) by means of rotation of the intermediate wheel, wherein the intermediate wheel (406) and the tensioning roller (408) have a common axis of rotation; Driving rotation of the first and second camshaft pulleys (142, 144) by a cam drive belt (146) driven by the tension pulley (408), the cam drive belt (146) contacting an outer surface of the first and second camshaft pulleys (142, 144) and the tension pulley (408); Driving rotation of a fuel pump drive gear (412) in direct meshing engagement with the idler gear (406) via the rotation of the idler gear, the fuel pump drive gear (412) being directly connected to a drive shaft (415) of a fuel pump (416); and Adjusting a gap amount between the teeth of the idler gear and the fuel pump drive gear (412) by adjusting a relative position between the teeth of a first toothed disk and the teeth of a second toothed disk of a scissor gear, wherein the scissor gear is either the fuel pump drive gear (412) or the idler gear (406). [12] The method of claim 11, wherein transmitting rotational movement from the crankshaft (132) to the idler gear (406) comprises rotating the crankshaft (132) in a first direction and rotating the idler gear in a second direction opposite to the first direction, wherein rotating the tension pulley (408) comprises rotating the tension pulley (408) in the second direction, and wherein the first toothed disk is fixedly coupled to a bearing of the scissors gear and the second toothed disk is rotatably coupled to the bearing. [13] The method of claim 12, further comprising rotating a first camshaft directly connected to the first camshaft pulley in the second direction and rotating a second camshaft directly connected to the second camshaft pulley in the second direction. [14] The method of claim 13, wherein driving rotation of the first and second camshaft pulleys (142, 144) comprises rotating the first and second camshaft pulleys (142, 144) at half the speed of the first camshaft and the second camshaft. [15] The method of claim 11, wherein the idler gear, the tension pulley (408), and the first and second camshaft pulleys (142, 144) are all disposed at a front end of the engine, the front end being opposite a rear end of the engine including a flywheel (134) of the engine, and wherein the fuel pump (416) is disposed in a direction of a rotational axis of the idler gear between the pistons of the engine and the idler gear (406) and the drive gear of the fuel pump (416), the fuel pump (416) further being positioned vertically above the crankshaft (132). [16] System for an engine, comprising: a front end comprising: a first end of a crankshaft (132); an idler gear assembly (404) comprising an idler gear (406) and a tensioner pulley (408), the idler gear (406) being in meshing engagement with the first end of the crankshaft (132) and the tensioner pulley (408) being connected to the idler gear (406) and having a common axis of rotation therewith; first and second camshaft pulleys (142, 144) connected to first and second camshafts; a cam drive belt (146) contacting the first and second camshaft pulleys (142, 144) and the tensioner pulley (408) respectively and not the first end (133) of the crankshaft (132); a fuel pump drive gear (412) in direct meshing engagement with the idler gear, the fuel pump drive gear (412) being directly connected to a drive shaft (415) of a fuel injection pump, the fuel injection pump being positioned further inside the engine than the front end of the engine and vertically above the crankshaft (132), the fuel injection pump being positioned in a direction of the rotational axis of the idler gear between pistons of the engine and the idler gear (406) and the fuel pump drive gear (412), cylinders (118) of the engine, each of which can accommodate one of the pistons, being arranged in a row; and an oil pump drive gear (403) in meshing engagement with a crankshaft pulley directly connected to the first end of the crankshaft (132) and directly connected to an input shaft of an oil pump, an oil pump belt contacting both the crankshaft pulley and the oil pump drive gear (403), the oil pump belt and the cam drive belt (146) being arranged in the same plane; and a rear end disposed opposite the front end, the rear end including a flywheel (134) connected to a second end of the crankshaft (132). [17] The system of claim 16, wherein the tension roller (408) has a smaller diameter than the idler gear (406), the idler gear (406) comprising a greater number of teeth than the first end (133) of the crankshaft (132). [18] The system of claim 16, wherein both the idler gear (406) and the fuel pump drive gear (412) are scissor gears comprising first and second toothed discs rotatable relative to each other to adjust a relative position of the teeth of the first disc and the second disc. [19] The system of claim 16, wherein the tension pulley (408) is disposed forward of the tension wheel relative to a front end front cover (141), the front cover (141) being adapted to cover the tension wheel assembly, and wherein the tension pulley (408), the oil pump drive belt, and the cam drive belt (146) are all disposed in a same plane, the rotational axis of the tension wheel being disposed normal to the plane. [20] The system of claim 16, wherein the front end further comprises a tensioner disposed vertically above the idler gear assembly (404) and vertically below the first and second camshaft pulleys (142, 144), one side of the tensioner contacting an outer surface of the cam drive belt (146) and an inner surface of the cam drive belt (146) contacting the first and second camshaft pulleys (142, 144).

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