Motor

Abstract

To make an engine more compact by allowing a balancer to be placed compactly in areas other than in front of the engine. An engine comprising: a timing chain 67, 68 on one side of the engine; and a timing chain drive sprocket 65, 66 driving the timing chain 67, 68, the timing chain drive sprocket 65, 66 being driven by a timing chain drive gear 64 arranged coaxially on the side of the engine, the timing chain drive gear 64 being driven by an idler driven gear 63, the idler driven gear 63 being driven by an idler drive gear 62, the idler drive gear 62 meshing with a predetermined gear 61 provided on a crankshaft 10 on which a balancer 80 is arranged coaxially with the idler drive gear 62.

Description

BACKGROUNDTechnical field

[0001] The present invention relates to an engine. State of the art

[0002] An engine with an internal combustion engine equipped with a balancer to suppress vibrations is known. This type of engine has a configuration in which a water pump shaft is attached and secured to one end of a front balancer shaft (see, for example, JP 2009-162202 A). SUMMARY

[0003] When placing the balancer, auxiliary devices can be provided that are driven coaxially with the same drive source, but it is difficult to place the balancer compactly outside the high degree of freedom area in front of the motor.

[0004] In view of the circumstances just described, the object of the present invention is to make an engine more compact by allowing a balancer to be compactly placed in areas other than in front of the engine.

[0005] An engine is provided with: a timing chain on one side of the engine; and a timing chain drive sprocket driving the timing chain, wherein the timing chain drive sprocket is driven by a timing chain drive gear (64) arranged coaxially on the side of the engine, wherein the timing chain drive gear is driven by an idler driven gear, wherein the idler driven gear is driven by an idler drive gear, wherein the idler drive gear meshes with a predetermined gear provided on a crankshaft in which a balancer is arranged coaxially with the idler drive gear.

[0006] According to the present invention, a balancer can be compactly placed in areas other than in front of an engine, whereby the engine can be made more compact. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of an engine according to an embodiment of the present invention; Fig. 2 is a cross-sectional view of the engine taken along a plane passing through a crankshaft, a mainshaft, and a front cylinder; Fig. 3 illustrates the peripheral structures of an idler gear support shaft and a timing chain drive shaft; Fig. 4 is a perspective view showing a cross section of the crankshaft together with the idler gear support shaft and the like; Fig. 5 is a perspective view showing a cross section of the idler gear support shaft together with the crankshaft and the like; Fig. 6 is a perspective view showing the idler gear support shaft along with its peripheral configuration; and Fig. Figure 7 shows the timing chain drive shaft along with its peripheral configuration. DETAILED DESCRIPTION

[0007] An embodiment of the present invention will be described below with reference to the drawings. Note that in the description, directions such as front, rear, left, right, top, and bottom are identical to directions with respect to a vehicle body unless otherwise specified. Furthermore, in each drawing, reference character FR denotes the front of the vehicle body, reference character UP denotes the top of the vehicle body, and reference character LH denotes the left side of the vehicle body. [Embodiment]

[0008] Fig. 1 is a perspective view of an engine 1 according to an embodiment of the present invention. The engine 1 in Fig. 1 is shown without a crankcase cover 2 covering the engine 1 from the right side.

[0009] The engine 1 is a V-type engine installed in a motorcycle, which can also be referred to as an internal combustion engine and power unit. The engine 1 includes a crankcase 11 in which a crankshaft 10 is rotatably supported, a front cylinder 12F (also called the first row) tilted forward and extending forward and upward from the top of the crankcase 11, and a rear cylinder 12R (also called the second row) tilted rearward and extending rearward and upward from the top of the crankcase 11.

[0010] Each of the cylinders 12F and 12R includes a cylinder block 12a, a cylinder head 12b connected to the top of the cylinder block 12a, and a head cover (not shown) closing the top of the cylinder head 12b, as well as a valve train 13 arranged between the cylinder head 12b and the head cover.

[0011] The crankcase 11 consists of a hollow housing that supports the crankshaft 10 and peripheral structures and is divided into left and right sections. However, the shape and structure of the crankcase 11 can be changed according to the specifications of the engine 1 and the like.

[0012] The crankshaft 10 is rotatably mounted in the crankcase 11 so that it extends in the direction of the vehicle width. Furthermore, a main shaft 21 is rotatably mounted in the crankcase 11 behind and below the crankshaft 10, with a countershaft 22 rotatably mounted below the crankshaft 12 and the main shaft 21. Furthermore, an idler gear support shaft 31 is rotatably mounted in the crankcase 11 above the rear of the crankshaft 10 and on the right side of the crankcase 11, with a timing chain drive shaft 32 rotatably mounted above the idler gear support shaft 31 and on the right side of the crankcase 11. The crankshaft 10, the main shaft 21, the countershaft 22, the idler gear support shaft 31, and the timing chain drive shaft 32 are parallel to one another.

[0013] Fig. Figure 2 is a cross-sectional view of the engine 1 taken along a plane passing through the crankshaft 10, the main shaft 21, and the front cylinder. The crankshaft 10 includes left and right journals 10a rotatably supported in the crankcase 11, and a crank 10b disposed between the left and right journals 10a and housed in a crank chamber 14. The crank 10b includes crank webs 10c integrally formed with the journals 10a, and a crank pin 10d interconnecting the crank webs 10c.

[0014] The crank webs 10c are formed integrally with crank weights 10e on the side of the axis of the crankshaft 10 opposite the crank pin 10d.

[0015] In the cylinder block 12a, a cylinder bore 15 is provided above the crank chamber 14, and a piston 16 is provided in the cylinder bore 15. The piston 16 is connected to the crankshaft 10 via a connecting rod 17.

[0016] The engine 1 in this configuration is designed such that the front and rear cylinders have different phases and the large connecting rod ends 17a of the front and rear cylinders resting on the crank pin 10d are in contact with one another via the crank webs 10c.

[0017] The right (one) end of the crankshaft 10 protrudes from the crankcase 11 to the right, with a primary drive gear 41 provided at this end. The primary drive gear 41 meshes with a primary driven gear 42 provided on the main shaft 21.

[0018] Located in a rear portion of the crankcase 11 is a gear chamber 18, which houses a constant-mesh gear 19. The gear chamber 18 and the crank chamber 14 are separated from each other by a partition wall 11w.

[0019] The transmission 19 includes the main shaft 21 running parallel to the crankshaft 10, the countershaft 22 running parallel to the main shaft 21, and a gear group 19g arranged on the main shaft 21 and the countershaft 22. The countershaft 22 functions as the output shaft of the engine 1 and drives a rear wheel, which constitutes the drive wheel, via a power transmission mechanism (e.g., a chain transmission mechanism).

[0020] At the right end of the main shaft 21, a clutch mechanism 51 is provided, which can interrupt the power transmission between the crankshaft 10 and the power transmission mechanism. The clutch mechanism 51 includes an outer clutch disc 53 connected to the primary output gear 42 via a damper mechanism 52, an inner clutch disc 54 fixed to the main shaft 21, and a friction disc 55 provided between the outer clutch disc 53 and the inner clutch disc 54. The clutch mechanism 51 is covered from the outside in the vehicle width direction by the crankcase cover 2. The crankcase cover 2 may also be referred to as a clutch cover.

[0021] As in Fig. As shown in Figure 2, the primary drive gear 41, a timing gear 61, and a balancer drive gear 71 are arranged at the right end of the crankshaft 10. These gears 41, 61, and 71 are arranged in a space formed between the crankcase 11 and the crankcase cover 2.

[0022] The crankcase cover 2 comprises a cylindrical portion 2t that projects into the engine to surround a tube 3 connected to the crankshaft 10. The space between the cylindrical portion 2t and the tube 3 is sealed by a sealing element 4, with the opening of the cylindrical portion 2t being closed on the outside in the vehicle width direction by a cap 5.

[0023] Fig. 3 shows the peripheral structures of the idler gear support shaft 31 and the timing chain drive shaft 32.

[0024] The engine 1 uses a semi-camshaft transmission system in which gears and timing chains are used in combination to drive the valve trains 13 of the front and rear cylinders.

[0025] In engine 1, the rotation of the crankshaft 10 is transmitted to an idler gear drive gear 62 provided on the idler gear support shaft 31 via the timing gear 61 fixed to the crankshaft 10. Then, the rotation of the idler gear drive gear 62 is transmitted to a timing chain drive gear 64 provided on the timing chain drive shaft 32 via an idler gear driven gear 63 provided on the idler gear support shaft 31.

[0026] As in Fig. 3, a first timing chain drive sprocket 65 for the rear cylinder and a second timing chain drive sprocket 66 for the front cylinder are attached to the timing chain drive shaft 32. The valve train 13 (camshaft of the valve train 13) of the rear cylinder is driven by a first timing chain 67 wound around the first timing chain drive sprocket 65, while the valve train 13 (camshaft of the valve train 13) of the front cylinder is driven by a second timing chain 68 wound around the second timing chain drive sprocket 66. As shown in the Fig. 1 and Fig. 3, the configuration for implementing the semi-camshaft transmission system focuses on the right side of the engine.

[0027] Fig. 4 is a perspective view showing a cross section of the crankshaft 10 together with the idler gear support shaft 31 and the like. Fig. 5 is a perspective view showing a cross section of the idler gear support shaft 31 together with the crankshaft 10 and the like. Fig. 6 is a perspective view showing the idler gear support shaft 31 along with its peripheral configuration.

[0028] As in Fig. 4, on the crankshaft 10, the balancer drive gear 71 is fixed to the right side of the crankshaft 10 (engine outside), the timing gear 61 is fixed to the inside of the balancer drive gear 71 in the crankshaft direction (engine inside), and the primary drive gear 41 is fixed to the inside of the timing gear 61 in the crankshaft direction (engine inside).

[0029] The number of teeth and diameters of the gears 71, 61, and 41 are determined according to the specifications of the engine 1, but in the present embodiment, the primary drive gear 41 is formed as the gear with the largest diameter. Since the balancer drive gear 71 drives a balancer 80, which will be described later, to suppress the primary vibrations of the engine 1, the gear ratio between the balancer drive gear 71 and the crankshaft 10 is 1:1, and the balancer 80 is driven at the same speed as the crankshaft 10.

[0030] The timing gear 61 slows the rotation of the crankshaft 10 by half and transmits the rotation to the valve train 13 (camshaft of the valve train 13). For this reason, the timing gear 61 is designed with a smaller diameter than the balancer drive gear 71.

[0031] As in Fig. As shown in Figure 5, the idler gear support shaft 31 has a hollow shape with a bottom separate from the crankcase 11 and is fixed to the crankcase 11 with its bottom abutting against the crankcase 11 by a fastener 31k inserted from the outside in the vehicle width direction. The fastener 31k is a single bolt according to the present embodiment. Note that the structure for fixing the idler gear support shaft 31 to the crankcase 11 can be changed as needed.

[0032] Two bearings 31a and 31b, which are needle bearings, are arranged next to the idler gear support shaft 31. The idler gear driven gear 63, which meshes with the timing gear 61, and the idler gear drive gear 62 are fixed to the outer peripheral surface of the bearing 31a located on the inside of the crankshaft direction (corresponding to the inside of the engine). Therefore, the idler gear driven gear 63 and the idler gear drive gear 62 are relatively rotatable with respect to the idler gear support shaft 31. These gears 63 and 62 rotate synchronously because they are fixed to each other.

[0033] A serashi gear 62s having the same diameter as the idler gear 62 is attached to the idler gear 62 so as to rotate relative to the idler gear 62. The serashi gear 62s meshes with the timing gear 61 and is biased by an elastic member in the opposite direction to the rotational direction of the timing gear 61 to absorb the backlash between the timing gear 61 and the idler gear 62. The serashi gear 62s is also called a scissor gear and is an example of a "backlash absorption mechanism" according to the present disclosure.

[0034] A balancer driven gear 72 meshing with the balancer drive gear 71 is fixed to the outer peripheral surface of the bearing 31b of the intermediate gear support shaft 31 directed outward in the crankshaft direction (corresponding to the engine outer side).

[0035] The balancer output gear 72 is fixedly connected to the balancer 80. As in Fig. As shown in Figure 6, the balancer 80 is formed by forming a portion of the balancer output gear 72 into a fan-shaped thick portion that bulges toward the right side of the engine (corresponding to the outer side toward the crankshaft). The balancer 80 functions as a primary balancer, suppressing the primary vibrations of the engine 1 by rotating at the same speed in synchronization with the crankshaft 10 (reverse). By adjusting the shape and weight of the balancer 80, the vibration suppression effect can be adjusted accordingly.

[0036] The structure of the balancer 80 is not limited to the structure described above. For example, the balancer 80 can be manufactured as a separate component from the idler gear 62, and the balancer 80 and the idler gear 62 can be connected to form a single unit. Furthermore, vibrations other than primary vibration can be suppressed by adjusting the number of teeth in the gears of a balancer drive system, the balancer 80, or the like.

[0037] As in Fig. As shown in Figure 5, the intermediate gear support shaft 31 is provided with a plurality of oil supply holes 31h. Lubricating oil is supplied to the support shaft 31, and the supplied lubricating oil is supplied to the bearings 31a and 31b and the gears 62 and 63 via the oil supply holes 31h.

[0038] As in Fig. As shown in Figure 3, the timing chain drive gear 64, which meshes with the idler gear driven gear 63 provided on the idler gear support shaft 31, is provided at the right end of the timing chain drive shaft 32. On the timing chain drive shaft 32, the second timing chain drive sprocket 66 for the front cylinder in the vehicle width direction (corresponding to the engine inside) is provided inside the timing chain drive gear 64, and the first timing chain drive sprocket 65 for the rear cylinder in the vehicle width direction (corresponding to the engine inside) is provided inside the second timing chain drive sprocket 66.

[0039] Fig. 7 shows the timing chain drive shaft 32 together with its peripheral configuration.

[0040] As in Fig. 7, the timing chain drive shaft 32, the timing chain drive gear 64 and the first and second timing chain drive sprockets 65 and 66 are made as one piece.

[0041] Bearings 33 and 34, which are roller bearings, are press-fitted at both ends of the timing chain drive shaft 32, with the first timing chain drive sprocket 65 being formed on the outer periphery of the press-fitted portion of the bearing 33 on the crankcase 11 side. Furthermore, the timing chain drive gear 64 is integrally formed on the outer periphery of the press-fitted portion of the bearing 34 on the crankcase cover 2 side. The first timing chain drive sprocket 65, the second timing chain drive sprocket 66, and the timing chain drive gear 64 are arranged coaxially.

[0042] In this configuration, since the timing chain drive shaft 32, the timing chain drive gear 64, the first timing chain drive sprocket 65, and the second timing chain drive sprocket 66 are manufactured as a single piece, the number of components can be reduced. Furthermore, since the first timing chain drive sprocket 65 is installed using the press-fit part of the bearing 33, the first timing chain drive sprocket 65 can be positioned closer to the inside in the vehicle width direction (engine inside).

[0043] Furthermore, in this configuration, as in the Fig. 3, Fig. 5 and the like, the first timing chain drive sprocket 65 is arranged at a position where it overlaps the crank weight 10e or the connecting rod large end 17a in the vertical direction perpendicular to the crankshaft direction. As a result, the first timing chain drive sprocket 65 and the first timing chain 67 can be arranged closer to the inside of the engine 1 in the left-right direction. Therefore, the engine 1 can be made more compact in the left-right direction (crankshaft direction).

[0044] As described above, the engine 1 according to the present embodiment includes the crankshaft 10, in which the connecting rod large ends 17a of the front and rear cylinders are adjacent to each other on the crankpin 10d via the crank webs 10c, and the timing chains 67 and 68 for the front and rear cylinders 12F and 12R, each of the timing chains 67 and 68 being located on one side of the engine. The timing chain drive sprockets 65 and 66, which drive the timing chains 67 and 68, respectively, are driven by a timing chain drive gear 64 coaxially disposed on the engine side. Furthermore, the timing chain drive gear 64 is driven by the idler gear driven gear 63, wherein the idler gear driven gear 63 is driven by the idler gear drive gear 62 meshing with the drive gear of the crankshaft 10.

[0045] As in the Fig. 3, Fig. 5 and the like, in the present embodiment, the first timing chain drive sprocket 65 is arranged among the timing chain drive sprockets 65 and 66, at a position where it overlaps the crank weight 10e or the connecting rod large end 17a in the vertical direction of the engine at right angles to the crankshaft direction. Therefore, the first timing chain drive sprocket 65 and the first timing chain 67 can be positioned closer to the inside of the engine 1 in the left-right direction, and the engine 1 can be made more compact in the width direction.

[0046] In addition, as in the Fig. 3 and Fig. 5, the idler gear drive gear 62 and the idler gear driven gear 63 synchronously and relative to the idler gear support shaft 31 carrying the gears 62 and 63, the idler gear support shaft 31 being fixed to the crankcase 11 of the engine 1.

[0047] This configuration eliminates the need for a bearing between the idler gear support shaft 31 and the crankcase 11, thereby making it possible to reduce the periphery of the idler gear support shaft 31.

[0048] In addition, the idler gear 62 is provided with a serashi gear 62s, which acts as a backlash absorption mechanism. This configuration allows the backlash absorption mechanism to be made compact.

[0049] Furthermore, the idler gear support shaft 31 has a hollow shape with a bottom, is fixed to the crankcase 11 with the bottom abutting against the crankcase 11, and includes the oil supply port 31h through which oil is supplied from the inside to the idler gear drive gear 62 and the idler gear driven gear 63. According to this configuration, the lubrication system for the gears on the idler gear support shaft 31 can be made compact.

[0050] It should be noted that the oil supply port 31h may be provided for supplying oil to the idler gear drive gear 62 and / or the idler gear driven gear 63.

[0051] As in Fig. As shown in Figure 1, the idler gear support shaft 31 is arranged between the crankshaft 10 and the main shaft 21, which runs parallel to the crankshaft 10. This configuration enables a compact arrangement of the idler gear support shaft 31 by effectively utilizing the space between the crankshaft 10 and the main shaft 21.

[0052] In addition, the engine contains, as shown in Fig. 5, the primary drive gear 41, which transmits the rotation of the crankshaft 10 to the main shaft 21, wherein the primary drive gear 41 is arranged further inboard of the engine than the idler driven gear 63. Since the primary drive gear 41 can be arranged closer to the inside of the engine in this configuration, the torsional moment acting on the crankshaft 10 can be reduced and the periphery of the crankshaft 10 can be made more compact.

[0053] Furthermore, the first timing chain drive sprocket 65, the second timing chain drive sprocket 66, and the timing chain drive gear 64 are coaxially and integrally formed, the bearings 33 and 34 are press-fitted at both ends of the integral member, and the first timing chain drive sprocket 65 is formed on the outer periphery of the portion where the bearing 33 is press-fitted on the crankcase 11 side. This configuration makes it easier to make the member including the timing chain drive sprockets 65 and 66 and the timing chain drive gear 64 compact in the axial direction, which advantageously leads to a reduction in the width of the engine 1.

[0054] Furthermore, in the engine 1 according to the present embodiment, as shown in Fig. 3, the timing chains 67 and 68 are provided on the engine side, and the timing chain drive sprockets 65 and 66, which drive the timing chains 67 and 68, respectively, are driven by the timing chain drive gear 64 arranged coaxially on the engine side. The timing chain drive gear 64 is driven by the idler driven gear 63, and the idler driven gear 63 is driven by the idler drive gear 62, which meshes with the timing gear 61 (predetermined gear) on the crankshaft 10. Furthermore, the balancer 80 is arranged coaxially with the idler drive gear 62.

[0055] According to this configuration, the balancer 80 can be placed compactly even in areas other than the high degree of freedom area in front of the motor, whereby the motor 1 can be made more compact.

[0056] Furthermore, the idler gear driven gear 63 and the idler gear drive gear 62 rotate synchronously relative to the idler gear support shaft 31 supporting these gears, and the balancer 80 rotates relative to the idler gear support shaft 31 at a different speed than the idler gear drive gear 62. According to this configuration, the rotational speed of the timing chain drive system, including the idler gear drive gear 62, and the balancer drive system can be adjusted independently of each other, while the balancer 80 is arranged coaxially with the idler gear drive gear 62, thereby ensuring the degree of freedom in the design of each drive system.

[0057] Furthermore, the balancer driven gear 72, which is driven by the balancer drive gear 71 on the crankshaft 10, and the balancer 80 are provided integrally with the balancer driven gear 72. According to this configuration, since the balancer drive gear 71 is provided for the balancer, the number of teeth for the balancer drive system and the timing chain drive system can be set differently, thereby increasing the degree of freedom of the gear ratio of each drive system. Furthermore, the balancer 80 is integrated with the balancer driven gear 72, which contributes to reducing the number of components and miniaturization.

[0058] In addition, the balancer 80 is positioned closer to the outside of the engine, that is, outward in the crankshaft direction, than the idler gear 62. According to this configuration, the timing chain drive system including the idler gear 62 can be positioned closer to the inside of the engine, thereby making the engine 1 more compact. Furthermore, when the specifications of the balancer 80 are changed, or when the specifications without the balancer 80 are changed, no major changes need to be made to the internal structure of the engine 1, such as the structure of the timing chain drive system.

[0059] In addition, as in the Fig. 3 and Fig. 5, the clutch mechanism 51 is provided, which interrupts the power transmission from the crankshaft 10, and the balancer 80 overlaps the clutch mechanism 51 in a direction perpendicular to the crankshaft direction in a cross-sectional view taken along a plane passing through the axis of the crankshaft 10 and the axis of the clutch mechanism 51 (corresponding to the axis of the main shaft 21). According to this configuration, by utilizing the space available in the direction perpendicular to the crankshaft direction with respect to the clutch mechanism 51, the balancer 80 can be arranged compactly.

[0060] Furthermore, the idler driven gear 63 is arranged closer to the outside of the engine, that is, outward in the crankshaft direction, than the primary drive gear 41 provided on the crankshaft 10, and the balancer driven gear 72 is arranged closer to the outside of the engine, that is, outward in the crankshaft direction, than the idler driven gear 63. According to this configuration, when the specifications of the balancer 80 are changed or when the specifications without the balancer 80 are changed, no major changes need to be made to the internal arrangement of the engine 1, for example, to the arrangement of the drive system including the primary drive gear 41 or to the arrangement of the drive system including the idler driven gear 63. [Other embodiments]

[0061] The embodiment described above describes only one aspect of the present invention and can be optionally modified and applied without departing from the gist of the present invention.

[0062] For example, in the above embodiment, the case where the first timing chain drive sprocket 65 is arranged at the position where it overlaps the crank weight 10e or the connecting rod large end 17a in the vertical direction of the engine was described, but the present invention is not limited to this, and the second timing chain drive sprocket 66 may be arranged at the position where it overlaps the crank weight 10e or the connecting rod large end 17a in the vertical direction of the engine. Furthermore, both the first timing chain drive sprocket 65 and the second timing chain drive sprocket 66 may be arranged at positions where they overlap the crank weight 10e or the connecting rod large end 17a in the vertical direction of the engine.

[0063] Furthermore, in the above embodiment, the case was described where the balancer 80 is coaxial with the idler gear 62 in the Fig.1 and the like, but the present invention is not limited thereto, and the balancer 80 may be arranged coaxially with the idler gear 62 in an engine other than a V-type engine.

[0064] Moreover, although the case where the present invention relates to an engine 1 mounted on a motorcycle has been described, the present invention is not limited thereto, and therefore can be applied to engines of saddle vehicles including vehicles other than motorcycles, as well as vehicles other than saddle vehicles, mobile units other than vehicles, and the like. [Configuration supported by the above embodiments]

[0065] The above embodiments support the following configurations.

[0066] (Configuration 1) An engine comprising: a timing chain on one side of the engine; and a timing chain drive sprocket that drives the timing chain, the timing chain drive sprocket being driven by a timing chain drive gear arranged coaxially on the engine side, the timing chain drive gear being driven by an idler driven gear, the idler driven gear being driven by an idler drive gear, the idler drive gear meshing with a predetermined gear provided on a crankshaft in which a balancer is arranged coaxially with the idler drive gear.

[0067] According to this configuration, the balancer can be placed compactly, which allows the engine to be made more compact.

[0068] (Configuration 2) The motor according to Configuration 1, in which the idler driven gear and the idler drive gear rotate synchronously and relative to an idler support shaft carrying the idler drive gear and the idler driven gear, wherein the balancer also rotates relative to the idler support shaft but at a different speed than the idler drive gear.

[0069] According to this configuration, the rotation speed of the timing chain drive system, including the idler gear, and the balancer drive system can be adjusted independently, while the balancer is arranged coaxially with the idler gear, and the degree of freedom in the formation of each drive system can be ensured.

[0070] (Configuration 3) The engine according to configuration 1 or 2 further comprises a balancer driven by a balancer drive gear provided on the crankshaft, the balancer being formed integrally with the balancer driven gear.

[0071] According to this configuration, since the balancer drive gear is specifically designed for the balancer, the number of teeth can be set differently for the balancer drive system and the timing chain drive system, allowing for increased freedom in the gear ratio of each drive system. Furthermore, the balancer is integrated into the balancer driven gear, which contributes to reducing the number of components and thus miniaturization.

[0072] (Configuration 4) The engine according to any one of configurations 1 to 3, in which the balancer is arranged closer to the outside of the engine than the idler drive gear.

[0073] With this configuration, the timing chain drive system, including the idler gear, can be positioned closer to the engine interior, making the engine more compact. Furthermore, changing the balancer specifications or changing the specifications without the balancer eliminates the need for major changes to the engine's internal structure.

[0074] (Configuration 5) The engine according to any one of configurations 1 to 4, further comprising a clutch mechanism that interrupts power transmission from the crankshaft, wherein, in a cross-sectional view taken along a plane passing through an axis of the crankshaft and an axis of the clutch mechanism, the balancer overlaps the clutch mechanism in a direction perpendicular to a direction of the crankshaft.

[0075] According to this configuration, the balancer can be arranged compactly by utilizing a space available in the direction perpendicular to the crankshaft with respect to the clutch mechanism.

[0076] (Configuration 6) The engine according to Configuration 3, in which the idler driven gear is arranged closer to the outside of the engine than a primary drive gear provided on the crankshaft, and the balancer driven gear is arranged closer to the outside of the engine than the idler driven gear.

[0077] According to this configuration, if the specifications of the balancer or the specifications without the balancer are changed, no major changes need to be made to the internal layout of the engine. LIST OF REFERENCE SYMBOLS 1 engine (combustion engine) 10 Crankshaft 10c crank web 10d crank pin 10e crank weight 11 Crankcase 12F, 12R cylinder 13 Valve train 17a large connecting rod end 21 Main shaft 31 Intermediate gear support shaft 31h oil supply opening 33, 34 camps 41 primary drive gear 51 Clutch mechanism 61 Control gear 62 Intermediate gear 62s Serashi gear (backlash absorption mechanism) 63 Intermediate gear output gear 64 Timing chain drive gear 65 first timing chain drive sprocket 66 second timing chain drive sprocket 67 first timing chain 68 second timing chain 71 Balancer drive gear 72 Balancer output gear 80 equalizers QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2009-162202 A

[0002]

Claims

[1] An engine comprising: a timing chain (67, 68) on one side of the engine; and a timing chain drive sprocket (65, 66) driving the timing chain (67, 68), the timing chain drive sprocket (65, 66) being driven by a timing chain drive gear (64) arranged coaxially on the side of the engine, the timing chain drive gear (64) being driven by an idler gear driven gear (63), the idler gear driven gear (63) being driven by an idler gear drive gear (62), the idler gear drive gear (62) meshing with a predetermined gear (61) provided on a crankshaft (10), characterized by , that a compensator (80) is arranged coaxially to the intermediate gear drive gear (62). [2] The engine according to claim 1, wherein the idler gear driven gear (63) and the idler gear drive gear (62) rotate synchronously and rotate relative to an idler gear support shaft (31) carrying the idler gear drive gear (62) and the idler gear driven gear (63), and the balancer (80) rotates relative to the idler gear support shaft (31) at a different speed than the idler gear drive gear (62). [3] The engine according to claim 1 or 2, further comprising a balancer driven gear (72) driven by a balancer drive gear (71) provided on the crankshaft (10), wherein the balancer (80) is formed integrally with the balancer output gear (72). [4] The engine according to claim 3, wherein the intermediate gear driven gear (63) is arranged closer to the outside of the engine than a primary drive gear (41) provided on the crankshaft (10), and the balancer output gear (72) is arranged closer to the outside of the engine than the idler output gear (63). [5] The engine of any preceding claim, wherein the balancer (80) is located closer to the outside of the engine than the idler drive gear (62). [6] The engine according to any one of the preceding claims, further comprising a clutch mechanism (51) which interrupts the power transmission via the crankshaft (10), wherein, in a cross-sectional view taken along a plane passing through an axis of the crankshaft (10) and an axis of the clutch mechanism (51), the balancer (80) overlaps the clutch mechanism (51) in a direction perpendicular to a direction of the crankshaft (10).

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