JP2009074677A - Engine and saddle type vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine capable of sufficiently securing capacity of an oil pan for a transmission, even when a vehicle width is restricted. <P>SOLUTION: This engine 2 has a crankshaft 40, a transmission having a driving pulley and a driven pulley, a first oil pan 110 receiving oil supplied to the crankshaft 40 and a second oil pan 140 receiving the oil supplied to the transmission 60 and separate from the first oil pan 110. In the engine 2, the crankshaft 40 extends in the vehicle width direction of a saddle type vehicle body mounted with the engine 2, and a driving pulley shaft 62 driving the driving pulley is arranged in parallel to the crankshaft 40, and at least a part of the first oil pan 110 and at least a part of the second oil pan 140, are respectively arranged in parallel to the crankshaft 40 side and the driving pulley shaft 62 side, and the second oil pan 140 has a part straddling the center C1 in the vehicle width direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an engine and a saddle riding type vehicle, and more particularly to securing a capacity of an oil pan for a transmission.

Conventionally, as an engine including a transmission having a drive pulley and a driven pulley, for example, in Patent Document 1, a primary shaft of a belt-type continuously variable transmission is arranged coaxially with a crankshaft, and below the primary shaft. Describes an automobile engine provided with an oil pan for receiving transmission oil.
Japanese Patent Application Laid-Open No. 2007-113637

  However, in the above prior art, an oil pan is provided below the primary shaft that is arranged coaxially with the crankshaft of the engine. For this reason, the conventional engine has to be large in the direction in which the crankshaft extends. Therefore, when the conventional engine is mounted on a saddle-ride type vehicle so that the direction in which the crankshaft extends coincides with the vehicle width direction, if an increase in the size of the engine in the vehicle width direction is to be suppressed, There was a problem that sufficient bread capacity could not be secured.

  The present invention has been made in view of the above problems, and an engine capable of sufficiently securing the capacity of an oil pan for a transmission while suppressing an increase in size in the vehicle width direction and a saddle riding provided with the engine. One of the purposes is to provide a type vehicle.

  An engine according to an embodiment of the present invention for solving the above problems includes a crankshaft, a transmission having a drive pulley and a driven pulley, a first oil pan that receives oil supplied to the crankshaft, An engine including the first oil pan and a separate second oil pan that receive oil supplied to a transmission, wherein the crankshaft is a saddle-type vehicle body on which the engine is mounted. A drive pulley shaft extending in the width direction and driving the drive pulley is disposed in parallel with the crankshaft, and at least a part of the first oil pan and at least a part of the second oil pan are respectively connected to the crank. The second oil pan is disposed in parallel on the shaft side and the drive pulley shaft side, and the second oil pan has a portion straddling the center in the vehicle width direction. If it carries out like this, the engine which can fully ensure the capacity | capacitance of the oil pan for transmissions can be provided, suppressing enlargement to a vehicle width direction.

  A straddle-type vehicle according to an embodiment of the present invention for solving the above-described problems is characterized by including any of the above-described engines. By so doing, it is possible to provide a straddle-type vehicle equipped with an engine that can sufficiently ensure the capacity of the oil pan for transmission while suppressing an increase in size in the vehicle width direction. Here, the saddle riding type vehicle is, for example, a motorcycle (including a scooter), a four-wheel buggy, a snowmobile, or the like.

  Hereinafter, an engine and a straddle-type vehicle according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the case where the engine according to the present invention is realized as a water-cooled four-cycle parallel three-cylinder engine and the straddle-type vehicle according to the present invention is realized as a scooter type motorcycle will be described as an example. In the present embodiment, front, rear, left, right, upper, and lower are front, rear, left, right, upper, and lower, respectively, as viewed from the rider driving the motorcycle. Also, the left-right direction is sometimes referred to as the vehicle width direction.

  First, the motorcycle will be described. FIG. 1 is a left side view of the motorcycle 1. As shown in FIG. 1, the motorcycle 1 includes a front wheel 3 and a rear wheel 4 rotatably supported by the vehicle body, a seat 5 on which a driver is seated, a handle 6 for steering the front wheel 3, and a rear wheel 4. An engine 2 that generates power to be driven is provided.

  The seat 5 extends from an intermediate position between the front wheel 3 and the rear wheel 4 to above the rear wheel 4 behind the handle 6. The seat 5 is a tandem seat having a front seat portion 5a on which a driver is seated at a front portion and a rear seat portion 5b on which a passenger is seated above a rear wheel. A driver seated on the seat 5 can steer the handle 6 to swing the front wheel 3 rotatably supported by the lower ends of the pair of left and right front forks 7 to the left and right.

  The engine 2 is fixed to a vehicle body frame (not shown) that forms the skeleton of the vehicle body of the motorcycle 1. The engine 2 has a cylinder portion 2b that houses a piston (not shown). The cylinder part 2b extends from the vicinity of the lower side of the front seating part 5a of the seat 5 while being inclined forward and upward. The engine 2 will be described in detail later.

  The motorcycle 1 further includes a shaft drive type driving force transmission device 8 that transmits the driving force of the engine 2 to the rear wheel 4. That is, the motorcycle 1 includes a drive shaft 9 extending in the front-rear direction from the engine 2 to the rear wheel 4 on the left side of the vehicle body.

  The drive shaft 9 is supported so as to be swingable up and down around a pivot shaft 11 extending in the vehicle width direction. Further, the bevel gear formed at the rear end of the drive shaft 9 meshes with the bevel gear formed at the left end of the rear wheel rotation shaft 4a that rotatably supports the rear wheel 4. The rear wheel 4 is supported so as to swing up and down about the pivot shaft 11.

  The motorcycle 1 includes a vehicle body cover 12 that covers the vehicle body. The vehicle body cover 12 has a front cowling 12a formed so as to cover the front of the vehicle body above the front wheel 3, and a leg shield 12b formed so as to cover the front of both feet of the driver seated on the front seat portion 5a of the seat 5. And a center cover 12c formed so as to cover the top of the vehicle body at a position between the handle 6 and the seat 5, and a left side and a right side of the vehicle body below the center cover 12c (that is, the vehicle width) And a pair of left and right planes 12f on which the driver seated on the front seating portion 5a of the seat 5 places the left foot and the right foot on the lower side portion of the side cover 12d. And a pair of left and right foot boards 12e.

  The center cover 12c extends from the position below the front end of the seat 5 while inclining upward toward the front. The inclination of the center cover 12c and the inclination of the cylinder portion 2b of the engine 2 disposed below the center cover 12c are substantially coincident with each other.

  When starting the running of the motorcycle 1, the engine 2 can be started by the starter motor 2c. Air and fuel are supplied to the cylinder portion 2b of the started engine 2 from an intake port (not shown) by a fuel injection method. The engine 2 generates power by burning fuel in the cylinder portion 2b. This power is transmitted to the rear wheel 4 via the drive shaft 9. As a result, the rear wheel 4 rotates and the motorcycle 1 travels forward. The exhaust of the engine 2 exhausted from the exhaust port (not shown) of the cylinder part 2b is exhausted from the silencer (muffler) 10 to the atmosphere.

  Next, the engine 2 will be described in detail. First, the 1st side surface of the engine 2 which concerns on this embodiment is demonstrated, referring FIGS. FIG. 2 is a left side view of the engine case 2 a that constitutes the outer shell of the engine 2. 3 and 4 are right side views of the engine case 2a. 2 and 3 show the engine case 2a in a state where a cover portion covering a part on the outer side in the vehicle width direction is removed. FIG. 5 is a cross-sectional view of the engine 2 along the line VV shown in FIG. FIG. 6 is a cross-sectional view of the engine 2 taken along the line VI-VI shown in FIGS. FIG. 7 is a cross-sectional view of engine 2 along the line VII-VII shown in FIG.

  The engine case 2 a includes a crankcase 20 that houses the crankshaft 40, and a transmission case 30 that houses the transmission 60. As shown in FIG. 5, the transmission 60 includes a drive pulley 61, a drive pulley shaft 62 that drives the drive pulley, a driven pulley 63, a driven pulley shaft 64 that drives the driven pulley, the drive pulley 61, and This is a wet-type continuously variable transmission having an endless metal belt 65 wound around a driven pulley 63.

  As shown in FIGS. 2 to 4, the crankcase 20 is configured to be vertically split by a split surface S <b> 1 passing through the axis P <b> 1 of the crankshaft 40. That is, the crankcase 20 is formed as a separate case and can be divided into upper and lower parts, and the upper case part 20a constituting a part above the dividing surface S1 (that is, the cylinder part 2b side), And a lower case portion 20b that constitutes a portion below the dividing surface S1. The crankcase 20 is configured by joining the mating surface at the lower end of the upper case portion 20a and the mating surface at the upper end of the lower case portion 20b on the dividing surface S1.

  As shown in FIGS. 5 to 7, the transmission case 30 is configured to be divided into right and left by a dividing surface S <b> 2 and a dividing surface S <b> 3 perpendicular to the axis P <b> 1 of the crankshaft 40. That is, the transmission case 30 is formed as a separate case and can be divided into left and right parts, and the right side of the transmission 60 is formed on the right side of the dividing surface S2 on the right side. A portion between the right case portion 30a that covers the side (the vehicle width direction outer side) and the divided surface S2 and the divided surface S3 on the left side to form the left side (the vehicle width direction) of the transmission 60 A left case portion 30b that covers the inner side), and a left end case portion 30c that forms a portion further to the left of the dividing surface S3 and covers a part of the left side of the left case portion 30b. Have. The mating surface at the left end of the right case portion 30a and the mating surface at the right end of the left case portion 30b are joined on the dividing surface S2, and at the left end of a part of the left case portion 30b. The transmission case 30 is configured by joining the mating surface and the mating surface at the right end of the left end case portion 30c on the dividing surface S3.

  The crankcase 20 and the transmission case 30 are integrated with each other by connecting the upper case portion 20a and the lower case portion 20b of the crankcase 20 to a part of the transmission case 30 and the other part, respectively. The engine case 2a is configured.

  That is, as shown in FIG. 2, the rear side portions of the upper case portion 20 a and the lower case portion 20 b and the front side portion of the transmission case 30 are arranged at positions that overlap (overlap) in the vehicle width direction. Yes. The upper case portion 20a and a part of the transmission case 30 that overlaps the upper case portion 20a are fastened and fixed in the vehicle width direction, and the lower case portion 20b and the transmission that overlaps the lower case portion 20b. The other part of the case 30 is fastened and fixed in the vehicle width direction.

  Specifically, as shown in FIGS. 2 and 5, a portion (clutch chamber 22) on the rear side of the portion (crank chamber 21) in which the crankshaft 40 is accommodated in the upper case portion 20 a and the lower case portion 20 b. On the right side, the front side portions of the left case portion 30b and the right case portion 30a are disposed so as to straddle both case portions of the upper case portion 20a and the lower case portion 20b (straddling the dividing surface S1). .

  2 and 3, the rear side portions of the upper case portion 20a and the lower case portion 20b, the front side portion of the left case portion 30b, and the right case portion 30a arranged in the vehicle width direction (see FIG. 4). A plurality of tightening holes 90 are formed at corresponding positions in each of the front side portions. Further, as shown in FIGS. 4 and 6, a bolt member 91 extending in the vehicle width direction is inserted through each of the plurality of fastening holes 90 across the three case members.

  That is, by the plurality of bolt members 91, the three case portions of the upper case portion 20a, the left case portion 30b, and the right case portion 30a are fastened and fixed in the vehicle width direction, and the lower case portion 20b and the left case portion The three case portions 30b and the right case portion 30a are also fastened and fixed in the vehicle width direction.

  In this way, the upper case portion 20a and the lower case portion 20b, and the left case portion 30b and the right case portion 30a are integrally coupled, thereby increasing the rigidity of the engine case 2a, particularly the crankcase 20. .

  As shown in FIGS. 2 to 5, a crank chamber 21 extending in the vehicle width direction is formed in the front side portion of the crankcase 20 in such an engine case 2 a. A crankshaft 40 is accommodated.

  Here, above the crank chamber 21, the above-mentioned cylinder portion 2b extends upward while being inclined forward. As shown in FIG. 5, the cylinder portion 2b includes a cylinder 13 in which three cylinder chambers 13a for accommodating three pistons 13b are formed in series in the vehicle width direction, and the three cylinders as shown in FIG. It has a cylinder head 14 in which three combustion chambers 14 a for compressing and burning fuel at a position corresponding to the chamber 13 a are formed, and a cover 15 for closing the upper end of the cylinder head 14.

  As shown in FIG. 2, the cylinder head 14 has an intake opening corresponding to each of the three combustion chambers 14a, one end opening to the side of the cylinder head 14 and the other end opening to the combustion chamber 14a. A port 14b and an exhaust port 14c are formed. The cylinder head 14 houses an intake valve 14d that opens and closes an opening of each intake port 14b to the combustion chamber 14a, and an exhaust valve 14e that opens and closes an opening of each exhaust port 14c to the combustion chamber 14a. is doing. The engine 2 employs a double overhead camshaft (DOHC) system as a drive mechanism for the intake valve 14d and the exhaust valve 14e.

  On the other hand, as shown in FIG. 5, the crankshaft 40 accommodated in the crank chamber 21 of the crankcase 20 is formed in a columnar shape extending in the vehicle width direction so that its axis coincides with the axis P1 of the crankshaft 40. The four journal portions 41a to 41d thus formed, a pair of six crank webs 42 formed in a plate shape extending in a direction perpendicular to the axis P1, and a pair at a position deviated from the axis P1. And three crank pins 43 extending in the vehicle width direction so as to connect the two crank webs 42. The journal portions 41a to 41d, the crank web 42, and the crank pin 43 are integrally formed.

  The three pairs of crank webs 42 are formed at positions corresponding to the three cylinder chambers 13 a formed in the cylinder 13. Each of the three crank pins 43 is connected to the lower end of a columnar connecting rod 13c that supports the piston 13b from below.

  The crankshaft 40 is supported by the crankcase 20 so as to rotate about its axis P1 in accordance with the reciprocating motion in the cylinder chamber 13a of the three pistons 13b connected via the connecting rod 13c.

  That is, as shown in FIG. 5, the left wall portion that closes the left side of the crank chamber 21 is formed with a shaft support portion 21 a that supports the journal portion 41 a that forms the left end portion of the crankshaft 40. A shaft support portion 21 d that pivotally supports a journal portion 41 d constituting the right end portion of the crankshaft 40 is formed on the right wall portion that closes the right side of the crank chamber 21. Further, in the crank chamber 21, a shaft support portion 21b that pivotally supports a journal portion 41b extending between the pair of crank webs 42 on the left end and the pair of center crank webs 42, and the center crank web 42 pair on the right side. A shaft support portion 21c that pivotally supports a journal portion 41c extending between the pair of crank webs 42 at one end is formed. The journal portions 41a to 41d of the crankshaft 40 are pivotally supported on the shaft support portions 21a to 21d by plain bearings (not shown) that are formed in a thin cylindrical shape and are arranged so as to cover the outer periphery of the journal portions 41a to 41d. Has been.

  Further, the left end portion of the crankshaft 40 extends to the left of the crank chamber 21, and a generator 44 that generates electric power according to the rotation of the crankshaft 40 is attached to the tip portion. The generator 44 includes a rotor that has a magnet and rotates integrally with the crankshaft 40, and a stator coil that is disposed to face the magnet. Then, when the rotor rotates in conjunction with the crankshaft 40, the generator 44 can generate electric power. The electric power generated by the generator 44 is supplied to, for example, a battery (not shown) provided in the motorcycle 1 (see FIG. 1). A cover member 20c that covers the outer side of the generator 44 in the vehicle width direction is detachably attached to the left side of the crank chamber 21.

  Further, between the crank web 42 at the right end of the crankshaft 40 and the shaft support portion 21d that supports the journal portion 41d at the right end, as shown in FIGS. A gear 45a is formed that meshes with a gear (not shown) on the outer periphery of a balancer 47 (see FIGS. 2 to 4) disposed below. The balancer 47 is rotatably supported by the crankcase 20 by a shaft (not shown) extending in the vehicle width direction. That is, the crankcase 20 is formed with a shaft support portion 47 a that supports a shaft for driving the balancer 47. The balancer 47 is disposed on the front side and slightly below the crankshaft 40 so that its axis is located on the split surface S1 of the crankcase 20.

  As shown in FIG. 5, the right end portion of the crankshaft 40 extends to the right of the crank chamber 21, and a gear 45b is formed at the tip portion. A chain 46 for opening and closing the intake valve 14d and the exhaust valve 14e (see FIG. 2) in the cylinder head 14 shown in FIG. 2 by the DOHC method is wound around the gear 45b. A cover member 20 d that covers the outer side in the vehicle width direction of the right end of the crankshaft 40 is detachably attached to the right side of the crank chamber 21.

  Further, as shown in FIG. 5, the engine 2 includes a clutch 50 that can connect and disconnect the driving force from the crankshaft 40 to the driving pulley shaft 62 of the transmission 60. The clutch 50 is accommodated in the crankcase 20.

  That is, the crankcase 20 is formed with a clutch chamber 22 that accommodates the clutch 50 in parallel with the crank chamber 21. The clutch chamber 22 is formed such that the left side portion of the crank chamber 21 protrudes rearward. The left wall portion that closes the left side of the clutch chamber 22 is formed as a detachable cover member 20e.

  In the present embodiment, the clutch 50 is a multi-plate clutch. The clutch 50 includes a clutch upstream portion 51 that always rotates in conjunction with the crankshaft 40, a clutch downstream portion 52 that can be connected to the clutch upstream portion 51, and a clutch shaft 53 that rotates integrally with the clutch downstream portion 52. And a pressing plate 54 for controlling connection and disconnection between the clutch upstream portion 51 and the clutch downstream portion 52.

  A gear 51 b is formed on the outer periphery of the clutch upstream portion 51. The gear 51 b meshes with a gear 42 a formed on the outer periphery of the crank web 42 on the right side of the pair of crank webs 42 on the left end of the crankshaft 40. For this reason, the clutch upstream portion 51 always rotates in conjunction with the crankshaft 40 while it is rotating.

  Further, the clutch upstream portion 51 has a plurality of upstream disks 51a disposed at predetermined intervals in the vehicle width direction, and a pressing disk 51b disposed on the right side of the plurality of upstream disks 51a. ing. Further, the clutch downstream portion 52 has a plurality of downstream disks 52a arranged at predetermined intervals in the vehicle width direction. The upstream disk 51a and the downstream disk 52a are alternately arranged so as to overlap in the vehicle width direction. The pressing plate 54 disposed on the left side of the upstream disk 51a and the downstream disk 52a is urged to the right side by a spring (not shown), and presses the upstream disk 51a and the downstream disk 52a. is doing. As a result, the clutch upstream portion 51 and the clutch downstream portion 52 are connected. In a state in which the clutch upstream portion 51 and the clutch downstream portion 52 are connected (hereinafter referred to as “connected state”), the clutch upstream portion 51, the clutch downstream portion 52, and the clutch shaft 53 rotate integrally, and the crankshaft Forty rotational driving forces are transmitted to the clutch shaft 53.

  On the other hand, by operating a rod (not shown) connected to the pressing plate 54 to move the pressing plate 54 to the left side, the connection between the upstream disk 51a and the downstream disk 52a can be released. Thus, in a state where the clutch upstream portion 51 and the clutch downstream portion 52 are disconnected (hereinafter referred to as “disconnected state”), only the clutch upstream portion 51 rotates, and therefore the rotational driving force of the crankshaft 40 is It is not transmitted to the clutch shaft 53. The rod for switching between the connected state and the connected state of the clutch 50 is operated by a driver of the motorcycle 1 by a clutch lever (not shown) provided on the handle 6 (see FIG. 1), for example. Further, it can be operated by an actuator (not shown) provided in the motorcycle 1. This actuator is, for example, an electrical instruction input from a driver via an instruction input means (not shown) provided in the motorcycle 1 or an engine control (not shown) provided in the motorcycle 1. It can be operated by hydraulic pressure or a motor based on an electrical instruction output from a unit (Engine Control Unit: ECU) based on the rotational speed of the engine 2 or the like. The clutch 50 may be a centrifugal clutch that switches between a connected state and a connected state according to the centrifugal force accompanying the rotation of the clutch upstream portion 51.

  As shown in FIGS. 2 and 5, the clutch shaft 53 is formed separately from the crankshaft 40, and is disposed in parallel to the crankshaft 40 at a position adjacent to the crankshaft 40. Further, the clutch shaft 53 is disposed behind the crankshaft 40 and above the split surface S1 of the crankshaft 40 and the crankcase 20.

  The clutch shaft 53 is rotatably supported by the crankcase 20. That is, as shown in FIG. 5, a clutch left shaft support portion 22 a that supports the left end of the clutch shaft 53 is formed on the left wall portion of the clutch chamber 22, and the right wall portion of the clutch chamber 22 has A clutch intermediate shaft support portion 22 b that supports the middle portion of the clutch shaft 53 is formed. Further, on the right side of the clutch chamber 22, a clutch right shaft support portion 22 c for supporting a right end portion of the clutch shaft 53 by extending a part of the rear wall of the crank chamber 21 further rearward is formed. ing. The clutch left shaft support portion 22a, the clutch middle shaft support portion 22b, and the clutch right shaft support portion 22c are all formed in the upper case portion 20a (see FIG. 2). The clutch shaft 53 is pivotally supported by the respective shaft support portions 22a to 22c by ball bearings.

  Further, as shown in FIG. 2, a crankcase side oil pan 23 for storing lubricating oil is formed in a part of the bottom of the crankcase 20 below the crank chamber 21. The lubricating oil flows from the crank chamber 21 and the clutch chamber 22 in the crankcase 20 into the crankcase-side oil pan 23 by gravity. Further, below the clutch chamber 22, adjacent to the crankcase side oil pan 23, another part of the bottom portion of the crankcase 20 (the rear side portion of the crankcase side oil pan 23) has the crankcase side oil pan. An oil tank 24 for storing the lubricating oil transferred from 23 is formed.

  As shown in FIGS. 2 and 6, the engine 2 includes a prime mover portion such as the crankshaft 40 and the cylinder portion 2b (the clutch 50 (see FIG. 5) in the driving force transmission path in the engine 2) and the upstream side thereof. The crankcase side oil pump 82 is provided to supply lubricating oil to the portion arranged in (1). The crankcase-side oil pump 82 is accommodated in the crankcase 20 and is a position between the clutch 50 and the drive pulley 61 in the vehicle width direction (see FIG. 6). And it arrange | positions below the drive pulley 61 (refer FIG. 2).

  The crankcase-side oil pump 82 includes a scavenge pump 83 for transferring the lubricating oil in the crankcase-side oil pan 23 to the oil tank 24, and the lubricating oil in the oil tank 24 for each part of the engine 2. And a feed pump 84 for pumping. The scavenge pump 83 and the feed pump 84 are integrally formed and supported between a pair of right pump support portion 29a and left pump support portion 29b which are part of the crankcase 20. In the present embodiment, both the scavenge pump 83 and the feed pump 84 are trochoid pumps, each having a pair of inner rotors 83a and 84a and outer rotors 83b and 84b.

  As shown in FIG. 2, the scavenge pump 83 is connected to the upper end of the strainer 25 for sucking lubricating oil from the crankcase side oil pan 23 into the scavenge pump 83. A suction portion 25 a for sucking lubricating oil in the crankcase side oil pan 23 is formed at the lower end of the strainer 25. Further, an oil passage (not shown) for allowing the lubricating oil discharged from the scavenge pump 83 to flow into the oil tank 24 is formed between the scavenge pump 83 and the upper end of the oil tank 24. .

  Further, as shown in FIG. 2, the upper end of the strainer 26 for sucking lubricating oil from the oil tank 24 to the feed pump 84 is connected to the feed pump 84. A suction portion 26 a for sucking lubricating oil in the oil tank 24 is formed at the lower end of the strainer 26. An oil passage 28 a for allowing lubricating oil discharged from the feed pump 84 to flow into the oil filter 27 is interposed between the feed pump 84 and the oil filter 27 formed in the front portion of the crankcase 20. Is formed.

  Further, as shown in FIG. 2, an oil main flow path (main gallery) 28 c extending in the vehicle width direction is formed in a lower portion of the crank chamber 21 in the crankcase 20, and the oil main flow path 28 c and the oil filter 27 are formed. An oil passage 28b is also formed between the two. The lubricating oil sent from the oil tank 24 to the oil filter 27 by the feed pump 84 is filtered by an element portion (not shown) provided in the oil filter 27, and then the oil flow path 28b extending rearward from the oil filter 27. Into the oil main flow path 28c. As shown in FIG. 5, the lubricating oil that has flowed into the oil main flow path 28 c includes oil injection flow paths 28 d formed in the shaft support portions 21 a to 21 d that support the journal portions 41 a to 41 d of the crankshaft 40. Then, the oil is supplied to the crank chamber 21 and the cylinder part 2b from an oil flow path 28e formed inside the journal parts 41a to 41d.

  Further, as shown in FIG. 6, the engine 2 includes a crankcase-side oil pump shaft 85 a that drives the crankcase-side oil pump 82, and a cooling that drives a coolant pump 87 that circulates the coolant in the engine 2. A water pump shaft 85 b is provided in the crankcase 20. The inner rotors 83a and 84a of the scavenge pump 83 and the feed pump 84 are coupled to the outer periphery of the crankcase side oil pump shaft 85a, and rotate integrally with the crankcase side oil pump shaft 85a. A cooling water pump 87 is attached to the left end of the cooling water pump shaft 85b. The crankcase side oil pump shaft 85a and the cooling water pump shaft 85b are formed separately from each other and are connected coaxially. That is, the left end of the crankcase-side oil pump shaft 85a and the right end of the cooling water pump shaft 85b are respectively formed with protrusions and grooves having shapes corresponding to each other. And the left end of the crankcase side oil pump shaft 85a and the right end of the coolant pump shaft 85b are connected. As a result, the crankcase-side oil pump shaft 85a and the coolant pump shaft 85b are aligned with each other to constitute a single crankcase-side pump shaft 85 and rotate integrally. .

  The crankcase-side pump shaft 85 is formed separately from the crankshaft 40 (see FIG. 5) and the clutch shaft 53, and is arranged in parallel to the clutch shaft 53 at a position adjacent to the clutch shaft 53. . The crankcase side pump shaft 85 is disposed behind the crankshaft 40 and below the drive pulley shaft 62 and the driven pulley shaft 64.

  The crankcase side pump shaft 85 is rotatably supported by the crankcase 20. That is, as shown in FIG. 6, a crankcase that supports the left end portion of the crankcase side pump shaft 85 is supported on the left wall portion of the crankcase 20 that closes the left side of the crankcase side oil pump 82. A side pump left shaft support 29c is formed. The middle part of the crankcase side pump shaft 85 is pivotally supported by the right pump support part 29a and the left pump support part 29b of the crankcase 20 via the crankcase side oil pump 82. Further, in the crankcase 20, a crankcase side pump right insertion portion 29 d into which the right end portion of the crankcase side pump shaft 85 is inserted is inserted into a right wall portion that closes the right side of the crankcase side oil pump 82. Is formed.

  An intermediate gear 86 that is rotatably supported by the crankcase 20 is disposed between the crankcase-side pump shaft 85 and the clutch shaft 53. A gear 51 c that meshes with the intermediate gear 86 is formed on the outer periphery of the clutch upstream portion 51 of the clutch 50, and a gear 85 c that meshes with the intermediate gear 86 is mounted on the outer periphery of the crankcase side pump shaft 85. That is, the clutch upstream portion 51 and the crankcase side pump shaft 85 are connected via the intermediate gear 86.

  For this reason, the crankcase-side pump shaft 85 rotates in conjunction with the crankshaft 40 regardless of whether the clutch 50 transmits or disconnects the driving force. Therefore, the crankcase-side pump 82 attached to the crankcase-side pump shaft 85 can continue to be driven not only when the clutch 50 is connected but also when the clutch 50 is connected or disconnected. Therefore, the crankcase-side oil pump 82 can supply lubricating oil to the crank chamber 21 and the cylinder portion 2b via the oil passages 28a to 28e described above while the crankshaft 40 is rotating.

  Further, the cooling water pump 87 driven by the rotation of the crankcase side pump shaft 85 can continue to be driven even when the clutch 50 is connected and disconnected, and the cooling water can be circulated to each part of the engine 2.

  On the other hand, as shown in FIG. 5, a transmission 60 is accommodated in the transmission case 30. That is, in the transmission case 30, a transmission chamber 31 extending in the front-rear direction is formed between the left case portion 30b and the right case portion 30a, and the transmission 60 is accommodated in the transmission chamber 31. . The transmission chamber 31 has a front portion disposed on the right side of the clutch chamber 22 of the crankcase 20, and a rear portion extending from the crankcase 20 to the rear side.

  A drive pulley 61 and a drive pulley shaft 62 are accommodated in the front portion of the transmission chamber 31. The drive pulley shaft 62 is formed separately from the crankshaft 40 and the clutch shaft 53, and is disposed in parallel with the crankshaft 40 at a position adjacent to the crankshaft 40.

  The drive pulley shaft 62 is rotatably supported by the transmission case 30. In other words, the right case portion 30 a that closes the right side of the transmission chamber 31 is formed with a drive-side pulley right shaft support portion 33 a that supports the right end of the drive pulley shaft 62. A drive side pulley left shaft support portion 33b that supports the left end portion of the drive pulley shaft 62 is formed in the left case portion 30b that closes the side. Further, as shown in FIGS. 3 and 4, both the drive-side pulley right shaft support portion 33 a and the drive-side pulley left shaft support portion 33 b are located above the dividing surface S <b> 1 of the crankcase 20 in the transmission case 30. Is formed.

  The drive pulley shaft 62 is connected coaxially with the clutch shaft 53. That is, as shown in FIGS. 5 and 6, the right end of the clutch shaft 53 and the left end of the drive pulley shaft 62 are coupled by spline coupling. As a result, the clutch shaft 53 and the drive pulley shaft 62 coincide with each other in the axis direction and extend in the vehicle width direction from the crankcase 20 to the transmission case 30 (hereinafter referred to as “composite main shaft 100”). Is configured to rotate integrally.

  That is, as shown in FIGS. 5 and 6, the composite main shaft 100 is formed separately from the crankshaft 40 and is disposed in parallel with the crankshaft 40 at a position adjacent to the crankshaft 40. The left end of the composite main shaft 100 is pivotally supported by the clutch left shaft support portion 22 a of the crankcase 20. Further, the right end of the composite main shaft 100 is pivotally supported by the drive side pulley right shaft support portion 33 a of the transmission case 30. Further, the middle portion of the composite main shaft 100 is pivotally supported by the clutch right shaft support portion 22 c of the crankcase 20 and the drive side pulley left shaft support portion 33 b of the transmission case 30. 2 to 4, the composite main shaft 100 is disposed behind the crankshaft 40 and above the split surface S1 of the crankshaft 40 and the crankcase 20.

  As shown in FIGS. 5 and 6, the clutch right shaft support portion 22c that supports the right end of the clutch shaft 53, and the drive side pulley left shaft support portion 33b that supports the left end of the drive pulley shaft 62, Are formed in shapes corresponding to each other and fitted. That is, the clutch right shaft support portion 22 c is formed with a cylindrical protrusion that extends rightward from the crankcase 20 around the right end portion of the clutch shaft 53. On the other hand, the drive-side pulley left shaft support portion 33b is formed with a cylindrical projecting portion extending leftward from the left case portion 30b around the left end portion of the drive pulley shaft 53. Here, the cylinder inner diameter of the clutch right shaft support portion 22c and the cylinder outer diameter of the drive side pulley left shaft support portion 33b are substantially equal, and the cylinder of the drive side pulley left shaft support portion 33b is the clutch right shaft support portion 22c. It is inserted in the cylinder. Further, an O (O) ring 30h is mounted between the cylindrical inner surface of the clutch right shaft support portion 22c and the cylindrical outer surface of the drive pulley left shaft support portion 33b for sealing.

  The drive pulley shaft 62 and the clutch shaft 53 are connected at a portion where the clutch right shaft support portion 22c and the drive side pulley left shaft support portion 33b are fitted. That is, in the composite main shaft 100, the connecting portion between the drive pulley shaft 62 and the clutch shaft 53 is inserted through the fitting portion between the clutch right shaft support portion 22c and the drive side pulley left shaft support portion 33b.

  In addition, each of the upper case portion 20a and the lower case portion 20b described above and the transmission case 30 are coupled mainly on the periphery of the composite main shaft 100 across the upper side and the lower side of the split surface S1 of the crankcase 20. Has been done. That is, as shown in FIGS. 2 and 3, the plurality of tightening holes 90 described above include the peripheral portion of the clutch shaft 53 in the upper case portion 20a, the peripheral portion of the clutch shaft 53 in the lower case portion 20b, and the right side. Each of the case portion 30a and the left case portion 30b is formed on a peripheral portion of the drive pulley shaft 62. As shown in FIGS. 4 and 6, each of the plurality of bolt members 91 includes three cases, that is, an upper case portion 20a and a lower case portion 20b, a left case portion 30b, and a right case portion 30a. The members are fastened and fixed around the composite main shaft 100 in the vehicle width direction.

  As shown in FIGS. 5 and 6, a drive pulley 61 is formed on the outer periphery of the drive pulley shaft 62. The drive pulley 61 includes a drive side fixed sheave 61a disposed on the inner side in the vehicle width direction, and a drive side movable sheave 61b formed on the outer side in the vehicle width direction. The driving side fixed sheave 61 a is formed integrally with the driving pulley shaft 62. The drive-side movable sheave 61b is formed separately from the drive pulley shaft 62, and the drive pulley shaft 62 is inserted through the central portion thereof. The drive-side movable sheave 61b can slide on the outer periphery of the drive pulley shaft 62 in a direction along the axis P2 of the drive pulley shaft 62. As the drive side movable sheave 61b slides, the distance between the drive side movable sheave 61b and the drive side fixed sheave 61a changes. As a result, the portion of the drive pulley 61 where the metal belt 65 is hung is changed. The diameter (hereinafter referred to as “effective diameter”) changes.

  The sliding of the drive side movable sheave 61b is controlled by hydraulic pressure. That is, on the right side of the drive side movable sheave 61b, a sealed space (hereinafter referred to as “drive side oil storage portion 61c”) that stores hydraulic control oil is formed between the drive side movable sheave 61b and the drive side movable sheave 61b. A drive side lid 61d is attached. When the amount of oil stored in the drive side oil storage portion 61c increases, the drive side movable sheave 61b moves to the left and the distance from the drive side fixed sheave 61a decreases, and the effective diameter of the drive pulley 61 increases. Will increase. Conversely, when the amount of oil stored in the drive side oil storage portion 61c decreases, the drive side movable sheave 61b moves to the right and the distance from the drive side fixed sheave 61a increases, and the effective diameter of the drive pulley 61 increases. Decrease.

  Further, as shown in FIG. 5, a driven pulley 63 and a driven pulley shaft 64 are accommodated behind the drive pulley 61 and the drive pulley shaft 62 in the transmission chamber 31. The driven pulley shaft 64 is formed separately from the crankshaft 40 and the clutch shaft 53, and is disposed in parallel to the drive pulley shaft 62 at a position adjacent to the drive pulley shaft 62.

  The driven pulley shaft 64 is rotatably supported by the transmission case 30. That is, the right case portion 30a is formed with a driven pulley right shaft support portion 34a that supports the right end of the driven pulley shaft 64, and the left case portion 30b is provided with a left end portion of the driven pulley shaft 64. A driven pulley left shaft support portion 34b that supports the shaft is formed.

  As described above, the right case portion 30a includes the drive pulley right shaft support portion 33a that supports the right end of the drive pulley shaft 62 and the driven pulley right shaft support portion 34a that supports the right end of the driven pulley shaft 64. And are integrally formed (see FIGS. 4 and 5). The left case portion 30b includes a driving pulley left shaft support portion 33b that supports the left end of the drive pulley shaft 62, a driven pulley left shaft support portion 34b that supports the left end of the driven pulley shaft 64, and (See FIGS. 3 and 5). That is, the drive side pulley right shaft support portion 33a and the driven pulley right shaft support portion 34a are integrally formed in the right case portion 30a, and the drive side pulley left shaft support portion 33b and the driven side pulley are formed in the left case portion 30b. The left shaft support portion 34b is integrally formed.

  As shown in FIG. 5, a driven pulley 63 is formed on the outer periphery of the driven pulley shaft 64. The driven pulley 63 includes a driven side fixed sheave 63a disposed on the outer side in the vehicle width direction, and a driven side movable sheave 63b formed on the inner side in the vehicle width direction. The driven side fixed sheave 63 a is formed integrally with the driven pulley shaft 64. On the other hand, the driven-side movable sheave 63b is formed separately from the driven pulley shaft 64, and the driven pulley shaft 64 is inserted through the central portion thereof. The driven movable sheave 63b is slidable on the outer periphery of the driven pulley shaft 64 in a direction along the axis P3 of the driven pulley shaft 64. As the driven movable sheave 63b slides, the distance between the driven movable sheave 63b and the driven fixed sheave 63a changes, and as a result, the effective diameter of the driven pulley 63 changes.

  On the left side of the driven-side movable sheave 63b, a sealed space (hereinafter referred to as “driven-side oil storage portion 63c”) that stores oil for hydraulic control is formed between the driven-side movable sheave 63b and the driven-side movable sheave 63b. A driven side lid 63d is attached. Further, a coil spring for urging the driven-side movable sheave 63b toward the driven-side fixed sheave 63a is accommodated in the driven-side oil storage portion 63c. When the effective diameter of the drive pulley 61 increases, the length of the metal belt 65 wound around the drive pulley 61 and the driven pulley 63 is constant, so that the driven-side movable pulley 63b is attached with a coil spring. It slides toward the driven side fixed sheave 63a against the force to reduce the effective diameter of the driven pulley 63. Conversely, when the effective diameter of the drive pulley 61 decreases, the effective diameter of the driven pulley 63 increases.

  Further, as shown in FIG. 5, the engine 2 includes an output shaft 70 for outputting the driving force transmitted from the crankshaft 40 to the driven pulley shaft 64 further downstream. The output shaft 70 is formed separately from the driven pulley shaft 64, and is disposed in parallel to the driven pulley shaft 64 at a position adjacent to the driven pulley shaft 64.

  As shown in FIGS. 2 to 5, the entire output shaft 70 is disposed outside the crankcase 20. That is, the entire output shaft 70 is accommodated in the transmission case 30 behind the crankcase 20. Specifically, in the transmission case 30, an output chamber 32 is formed between the left case portion 30 b and the left end case portion 30 c, and the left side portion of the output shaft 70 is accommodated in the output chamber 32. The right side portion of the output shaft 70 is accommodated in the transmission chamber 31.

  Further, the output shaft 70 is coaxially formed between the output shaft right portion 70 a that is a right side portion accommodated in the transmission chamber 31 and the output shaft left portion 70 b that is a left side portion accommodated in the output chamber 32. It is comprised by connecting to. That is, as shown in FIG. 5, the left end of the output shaft right portion 70a and the right end of the output shaft left portion 70b are formed in a corresponding cylindrical shape and are fitted.

  Further, the output shaft right part 70a and the output shaft left part 70b are connected so as to be separable from side to side. That is, an engagement groove having a predetermined length extending in the vehicle width direction is formed across the output shaft right portion 70a and the output shaft left portion 70b at the connecting portion between the output shaft right portion 70a and the output shaft left portion 70b. Has been. On the other hand, a cylindrical engaging member 70c that extends in the vehicle width direction and engages with the engaging groove is mounted on the outer periphery of the connecting portion over the output shaft right portion 70a and the output shaft left portion 70b. A rod (not shown) is attached to the protruding portion formed on the outer periphery of the engaging member 70c. By operating this rod, the engaging member 70c can slide on the outer periphery of the output shaft 70 along the axis P4 of the output shaft 70. That is, in the coupled state shown in FIG. 5, the engaging member 70c is disposed across the output shaft right part 70a and the output shaft left part 70b. For example, the driver of the motorcycle 1 holds the rod described above. By operating, the engaging member 70c can be slid further to the left side than the left end of the output shaft right portion 70a, and can be disposed only on the outer periphery of the output shaft left portion 70b. As a result, the connection between the output shaft right portion 70a and the output shaft left portion 70b can be released and separated. In this separated state, the output shaft left portion 70b can rotate independently of the output shaft right portion 70a.

  The output shaft 70 is rotatably supported by the transmission case 30. That is, the right case portion 30a is formed with an output right shaft support portion 35a that supports the right end of the output shaft 70 (that is, the right end of the output shaft right portion 70a), and the output chamber of the left end case portion 30c. 32, an output left shaft support portion 35c that supports the left end portion of the output shaft 70 (that is, the left end portion of the output shaft left portion 70b) is formed. The left case portion 30b is formed with an output middle shaft support portion 35b that supports a middle portion of the output shaft 70 (that is, a connecting portion between the output shaft right portion 70a and the output shaft left portion 70b). That is, the output shaft right portion 70a and the output shaft left portion 70b are connected in a through hole formed in the output middle shaft support portion 35b that is a boundary portion between the transmission chamber 31 and the output chamber 32.

  A gear 70d is integrally attached to the right end portion of the output shaft 70. The gear 70d meshes with a gear 64a attached to the right end portion of the driven pulley shaft 64. For this reason, the output shaft 70 rotates in conjunction with the driven pulley shaft 64.

  As shown in FIG. 5, the output chamber 32 accommodates a connecting shaft 71 that connects the output shaft 70 and the drive shaft (see FIG. 1). The connecting shaft 71 is formed to extend rearward from the left side of the output shaft 70.

  A bevel gear 71 a that meshes with a bevel gear 70 e formed at the left end of the output shaft 70 is attached to the front end of the connecting shaft 71. For this reason, the connecting shaft 71 rotates in conjunction with the output shaft 70. A free joint (universal joint) 71 b for rotatably connecting the front end of the drive shaft 9 is attached to the rear end of the connecting shaft 71.

  Further, the connecting shaft 71 is rotatably supported by the transmission case 30. That is, a front shaft support portion 36 a that supports the front end portion of the connecting shaft 71 is formed in the front portion of the left end case portion 30 c in the output chamber 32, and the rear portion in the output chamber 32 has A connected rear shaft support portion 36b that supports the rear end portion of the connection shaft 71 is formed.

  Further, as shown in FIG. 6, the engine 2 includes a transmission-side oil pump 80 that supplies oil to the transmission 60. The transmission-side oil pump 80 is accommodated in the transmission chamber 31 of the transmission case 30. That is, the transmission-side oil pump 80 is adjacent to the drive pulley 61 and the driven pulley 63 and below the drive pulley 61 and the driven pulley 63 in the transmission chamber 31 as shown in FIGS. Has been placed.

  As shown in FIG. 6, in this embodiment, the transmission-side oil pump 80 is a trochoid pump, and has a pair of inner rotor 80a and outer rotor 80b. The transmission-side oil pump 80 is supported by a transmission-side pump support portion 37 that is a part of the left case portion 30 b of the transmission case 30.

  The engine 2 also includes a transmission-side pump shaft 81 for driving the transmission-side oil pump 80. The inner rotor 80 a of the transmission-side oil pump 80 is coupled to the outer periphery of the right-hand end of the transmission-side pump shaft 81 and rotates integrally with the transmission-side pump shaft 81.

  The transmission-side pump shaft 81 is formed separately from the crankshaft 40, the clutch shaft 53, the drive pulley shaft 62, and the driven pulley shaft 64, and is driven at a position adjacent to the drive pulley shaft 62 and the driven pulley shaft 64. The pulley shaft 62 and the driven pulley shaft 64 are arranged in parallel. As shown in FIGS. 3 and 4, the transmission-side pump shaft 81 is disposed behind the crankshaft 40 and in front of the output shaft 70 and below the drive pulley shaft 62 and the driven pulley shaft 64. Has been. That is, the transmission-side pump shaft 81 is a position surrounded by the crankshaft 40, the drive pulley shaft 62, the driven pulley shaft 64, and the output shaft 70, and is disposed below the split surface S <b> 1 of the crankcase 20. ing.

  The transmission-side pump shaft 81 is rotatably supported by the transmission case 30. That is, as shown in FIG. 6, the transmission-side pump shaft 81 is pivotally supported by the transmission-side pump support portion 37 of the left case portion 30 b via the transmission-side oil pump 80. A transmission side pump insertion portion 37c through which the left end of the transmission side pump shaft 81 is inserted is formed in a portion of the left case portion 30b that covers the left side of the transmission side oil pump 80. Yes.

  The transmission-side pump shaft 81 is connected coaxially with the crankcase-side pump shaft 85. That is, as shown in FIG. 6, the left end of the transmission-side pump shaft 81 is coupled to the right end of the crankcase-side pump shaft 85. That is, the connecting portion between the transmission-side pump shaft 81 and the crankcase-side pump shaft 85 has a predetermined length extending in the vehicle width direction across the transmission-side pump shaft 81 and the crankcase-side pump shaft 85. Grooves are formed. A cylindrical engagement member 88 that extends in the vehicle width direction and engages with the engagement groove is mounted on the outer periphery of the connection portion over the transmission-side pump shaft 81 and the crankcase-side pump shaft 85. Yes. As a result, the crankcase-side pump shaft 85 and the transmission-side pump shaft 81 have a single shaft (hereinafter referred to as “composite”) that extends in the vehicle width direction from the crankcase 20 to the transmission case 30 with the axes aligned. Pump shaft 101 ") and is configured to rotate integrally.

  The composite pump shaft 101 is formed separately from the crankshaft 40 and the composite main shaft 100, and is disposed in parallel to the composite main shaft 100 at a position adjacent to the composite main shaft 100. The left end of the composite pump shaft 101 is pivotally supported by the crankcase side pump left shaft support portion 29c of the crankcase 20. Further, the middle portion of the composite pump shaft 101 is pivotally supported by the right pump support portion 29a and the left pump support portion 29b of the crankcase 20 via the crankcase side oil pump 82. Further, the right end of the composite pump shaft 101 is pivotally supported by the transmission-side pump support portion 37 of the transmission case 30 via the transmission-side oil pump 80.

  The composite pump shaft 101 rotates in conjunction with the crankshaft 40 regardless of connection / disconnection of the driving force transmitted by the clutch 50. Therefore, the transmission-side pump 81 attached to the right end of the composite pump shaft 101 can continue to be driven not only when the clutch 50 is connected but also when the clutch 50 is connected or disconnected. For this reason, the transmission-side oil pump 81 can supply hydraulic control oil and lubricating oil to the transmission 60 while the crankshaft 40 is rotating.

  Further, the crankcase side pump right insertion portion 29d through which the right end of the crankcase side pump shaft 85 is inserted and the transmission side pump insertion portion 37c through which the left end of the transmission side pump shaft 81 is inserted are They are formed in shapes corresponding to each other and fitted. In other words, the crankcase-side pump right insertion portion 29d is formed with a cylindrical protrusion that extends rightward from the crankcase 20 around the crankcase-side pump shaft 85. On the other hand, the transmission-side pump insertion portion 37 c is formed with a cylindrical protrusion that extends leftward from the left case portion 30 b around the transmission-side pump shaft 81. Here, the cylinder outer diameter of the crankcase-side pump right insertion portion 29d and the cylinder inner diameter of the transmission-side pump insertion portion 37c are substantially equal, and the cylinder of the crankcase-side pump right insertion portion 29d corresponds to the speed change. It is inserted in the cylinder of the machine side pump insertion part 37c.

  The crankcase-side pump shaft 85 and the transmission-side pump shaft 81 are connected at a portion where the crankcase-side pump right insertion portion 29d and the transmission-side pump insertion portion 37c are fitted. That is, in the composite pump shaft 101, a connecting portion between the crankcase side pump shaft 85 and the transmission side pump shaft 81 is a fitting portion between the crankcase side pump right insertion portion 29d and the transmission side pump insertion portion 37c. It is inserted.

  Further, the coupling between the lower case portion 20 b and the transmission case 30 described above is also performed around the composite pump shaft 101. That is, as shown in FIGS. 2 and 3, the plurality of tightening holes 90 described above include the peripheral portion of the crankcase-side pump shaft 85 in the lower case portion 20b, the right case portion 30a, and the left case portion 30b. It is formed in the peripheral part of the transmission side pump shaft 81, respectively. As shown in FIGS. 4 and 6, the three case members, that is, the lower case portion 20 b, the left case portion 30 b, and the right case portion 30 a, are combined with the composite oil shaft 101 by each of the plurality of bolt members 91. It is fastened and fixed around the car in the width direction.

  2 to 4, 6, and 7, the transmission case 30 has a transmission-side oil pan 38 that stores oil supplied to the transmission 60 by the transmission-side oil pump 80. Is formed. As shown in FIG. 7, the transmission-side oil pan 38 has a lower opening 30 d formed at the lower end of the bottom of the left case portion 30 b among the three case members 30 a to 30 c constituting the transmission case 30. It is provided so as to be closed from the side. That is, the opening 30d of the left case portion 30b integrally formed as one case member is closed by the transmission-side oil pan 38 formed integrally.

  For this reason, sealing of the joint portion between the mating surface 30e around the opening 30d at the lower end of the left case portion 30b and the mating surface 38a at the upper end of the transmission-side oil pan 38 can be reliably and easily achieved. In the left case portion 30b, a through hole 30f is formed in a part of a wall part that partitions the transmission chamber 31 and the opening 30d, and a part of a wall part that partitions the output chamber 32 and the opening 30d is penetrated. A hole 30g is formed. As a result, the lubricating oil supplied into the transmission chamber 31 flows down to the transmission side oil pan 38 from the through hole 30f, and the lubricating oil supplied into the output chamber 32 passes through the through hole 30g. 38 flows down.

  Further, as shown in FIGS. 3, 4, and 6, the transmission-side oil pan 38 has a crankcase of the crankcase 20 that extends rearward from a lower portion of the transmission-side oil pump 80 in the left case portion 30b. The right side of the case side oil pan 23 and the oil tank 24 extends to the rear end of the left case portion 30b. 2 and 7, the rear end portion of the transmission-side oil pan 38 extends below the output shaft 70 with the rear side of the oil tank 24 facing leftward. As described above, the transmission-side oil pan 38 is formed so as to extend from the right side to the rear side of the crankcase-side oil pan 23 and the oil tank 24, and has a sufficient oil capacity.

  As shown in FIGS. 4, 6, and 7, a control device 200 that controls supply of oil to the transmission 60 and the output shaft 70 is disposed in the transmission-side oil pan 38. On the other hand, as shown in FIG. 4, the transmission-side pump support portion 37 discharges oil from the transmission-side oil pump 80 and the suction-side flow path 37 a for sucking oil into the transmission-side oil pump 80. For this purpose, a discharge channel 37b is formed. One end of the suction channel 37 a is connected to the suction port 80 c of the transmission-side oil pump 80, and the other end is connected to the control device 200. One end of the discharge passage 37b is connected to the discharge port 80d of the transmission-side oil pump 80, and the other end is connected to the control device. As shown in FIGS. 4 and 7, a strainer 201 for sucking oil in the transmission-side oil pan 38 into the control device 200 extends downward from the control device 200. At the lower end portion of the strainer 201, a suction portion 201a is formed near the bottom surface of the transmission-side oil pan 38 for sucking oil.

  Also, as shown in FIGS. 4, 5, and 7, the right case portion 30a has one end opened to the right end of the drive pulley right shaft support portion 33a and the other end below the right case portion 30a. An oil passage 39a that opens to a part of the left end surface of the side portion (that is, the mating surface disposed on the dividing surface S2), and one end that opens to the right end of the driven pulley right shaft support portion 34a; An oil flow path 39b having the other end opened to the other part of the left end surface of the lower portion of the right case portion 30a, one end opened to the output right shaft support portion 35a, and the other end to the right case portion 30a. And an oil passage 39c that opens to another part of the left end surface of the lower side portion of the lower side portion of the lower side portion of the lower side portion.

  On the other hand, as shown in FIGS. 4 and 7, the left case portion 30b has one end at the right case of the right end surface of the left case portion 30b (that is, the mating surface disposed on the dividing surface S2). Three oil flow paths 39d to 39f that open at positions corresponding to the openings of the three oil flow paths 39a to 39c formed on the left end surface of the portion 30a and whose other ends are connected to the control device 200 are independent of each other. Is formed. As described above, in the transmission case 30, the drive side pulley right shaft support portion 33a, the driven pulley right shaft support portion 34a, and the output right shaft support portion 35a are straddled across the left case portion 30b and the right case portion 30a. , Oil flow paths 39a to 39f connecting the control device 200 are formed.

  As shown in FIGS. 5 to 7, each of the drive pulley shaft 62, the driven pulley shaft 64, and the output shaft 70 extends along the shaft centers P2, P3, and P4 and opens to the right end. Hollow portions 62a, 64b, and 70f are formed respectively. In addition, oil passages 62b, 64c, and 70g that extend radially outward from the hollow portions 62a, 64b, and 70f and open to the outer peripheral surface are provided in the drive pulley shaft 62, the driven pulley shaft 64, and the output shaft 70, respectively. Is formed. The drive-side movable sheave 61b and the driven-side movable sheave 63b communicate with the hollow portions 62a and 64b of the drive pulley shaft 62 and the driven pulley shaft 64, the drive-side oil storage portion 61c, and the driven-side oil storage portion 63c, respectively. Oil passages 61e and 63e are formed.

  Therefore, by driving the transmission-side oil pump 80, oil for hydraulic control can be supplied to the drive-side oil storage portion 61c and the driven-side oil storage portion 63c, respectively. That is, when the transmission-side pump shaft 81 rotates in conjunction with the crankshaft 40 and the transmission-side oil pump 80 is driven, the oil stored in the transmission-side oil pan 38 flows into the control device 200 via the strainer 201. Further, the oil is sucked into the transmission-side oil pump 80 through the suction flow path 37a (see FIG. 4). The sucked oil is discharged from the transmission-side oil pump 80, flows into the control device 200 via the discharge flow path 37b (see FIG. 4), and further, an oil flow path 39d formed in the left case portion 30b. To -39f.

  At this time, the control device 200 can independently adjust the opening and closing of control valves (not shown) provided in the connection portions with the oil flow paths 39d to 39f formed in the left case portion 30b. it can. That is, for example, when the effective diameter of the drive pulley 61 is increased, the control device 200 opens the control valve of the oil flow path 39d that communicates with the drive pulley shaft 62 and the oil flow path that communicates with the driven pulley shaft 64. The control valve 39e is closed. As a result, the oil is selectively pumped from the control device 200 to the drive-side oil accommodating portion 61c of the drive pulley 61 through the oil flow passage 39d of the left case portion 30b and the oil flow passage 39a of the right case portion 30a. Thus, the drive side movable sheave 61b (see FIGS. 5 and 6) slides to the left side, and the effective diameter of the drive pulley 61 increases.

  The oil stored in the transmission-side oil pan 38 is used for both hydraulic control of the transmission 60 and lubrication of the transmission 60, the output shaft 70, and the connecting shaft 71. In other words, in the engine 2, one transmission-side oil pump 80 supplies the oil in the transmission-side oil pan 38 to the transmission 60 for hydraulic control as described above, and the gear-shifting for lubrication. Oil in the machine-side oil pan 38 is supplied to the transmission 60, the output shaft 70, and the connecting shaft 71. The transmission case 30 is formed with an oil passage (not shown) whose one end opens into the transmission chamber 31 and the output chamber 32. The lubricating oil pumped by the transmission-side oil pump 80 is The oil passage can be supplied into the transmission chamber 31 and the output chamber 32.

  FIG. 8 is an explanatory diagram showing the relative positional relationship between the shafts arranged in parallel to the engine case 2a when the engine 2 is viewed from the left side. That is, FIG. 8 shows the shaft 47b of the balancer 47, the crankshaft 40, the drive pulley shaft 62, the driven pulley shaft 64, the output shaft 70, and the transmission-side pump shaft 81. Note that the direction indicated by the arrow F shown in FIG. 8 is the front direction of the engine 2.

  Further, as described above, the drive pulley shaft 62 and the clutch shaft 53 are coaxially connected to constitute the composite main shaft 100 (see FIG. 5), so that the clutch shaft 53 and the composite main shaft 100 are driven in FIG. The pulley shaft 62 is disposed at the same position. Further, since the transmission-side pump shaft 81 and the crankcase-side pump shaft 85 are coaxially connected to constitute the composite pump shaft 101 (see FIG. 6), the crankcase-side pump shaft 85 and the composite pump shaft 101 are combined. Is disposed at the same position as the transmission-side pump shaft 81 in FIG.

  Further, in FIG. 8, a plane (horizontal plane) showing a horizontal direction when the engine 2 is mounted on the motorcycle 1 and the split surface S1 of the crankcase passing through the axis P6 of the balancer shaft 47b and the axis P1 of the crankshaft 40. ) S4, a plane S5 passing through the axis P1 of the crankshaft 40 and the axis P4 of the output shaft 70, a plane S6 passing through the axis P1 of the crankshaft 40 and perpendicular to the plane S5, and an axis P4 of the output shaft 70 Passes through the plane S7 perpendicular to the plane S5 and the axis P2 of the drive pulley shaft 62, passes through the plane S8 parallel to the split surface S1 of the crankcase 20 and the axis P2 of the drive pulley shaft 62, and is perpendicular to the plane S5. A flat plane S9 is shown.

  For example, in the engine case 2 a shown in FIG. 2, the horizontal plane S <b> 4 extends on the extension line of the flat bottom surface of the crankcase side oil pan 23, the oil tank 34, and the transmission side oil pan 38. The horizontal plane S4 shown in FIG. 2 is also an end surface located on the lowest side of the engine case 2a.

  As described above, the engine 2 includes the crankshaft 40 driven by the reciprocating motion of a piston (not shown) housed in the cylinder portion 2b (see FIG. 2), and the drive pulley shaft driven by the rotation of the crankshaft 40. 62, a driven pulley shaft 64 driven by the rotation of the drive pulley shaft 62, an output shaft 70 driven by the rotation of the driven pulley shaft 64, and a transmission side pump driven by the rotation of the crank shaft 40 And a shaft 81. The crankshaft 40, the drive pulley shaft 62, the driven pulley shaft 64, the output shaft 70, and the transmission side pump shaft 81 are formed separately from each other and arranged in parallel.

  As described above, the composite pump shaft 101 including the transmission-side pump shaft 81 and the crankcase-side pump shaft 85 is connected to the clutch upstream portion 51 via the intermediate gear 86 that is an idle gear. The composite pump shaft 101 may be connected to a shaft provided upstream of the clutch 50 in driving force transmission via an idle gear.

  A crankcase-side oil pump 82 that supplies oil to the crankcase 20 is attached to the composite pump shaft 101 including the transmission-side pump shaft 81 and the crankcase-side pump shaft 85.

  In addition to such a configuration, in the engine case 2a, the drive pulley shaft 62 and the driven pulley shaft 64 are disposed between the crank shaft 40 and the output shaft 70, and are disposed above the plane S5. Yes. Specifically, both the axis P2 of the drive pulley shaft 62 and the axis P3 of the driven pulley 64 are located between the plane S6 and the plane S7, and are located above the plane S5.

  The transmission-side pump shaft 81 is disposed between the crankshaft 40 and the output shaft 70. Specifically, the axis P5 of the transmission-side pump shaft 81 is located between the plane S6 and the plane S7.

  Further, the transmission-side pump shaft 81 is disposed on the plane S5 side with respect to the drive pulley shaft 62 and the driven pulley shaft 64. Specifically, the shaft center P5 of the transmission-side pump shaft 81 is located below the plane S5.

  Note that the shaft center P5 of the transmission-side pump shaft 81 is, for example, on the upper side of the plane S5 and disposed below either the shaft center P2 of the drive pulley shaft 62 or the shaft center P3 of the driven pulley shaft 64. It may be located on the plane S5 side from a plane (not shown) passing through the plane and parallel to the plane S5.

  Thus, the transmission-side pump shaft 81 is disposed at a position surrounded by the crankshaft 40, the drive pulley shaft 62, the driven pulley shaft 64, and the output shaft 70 in a side view of the engine 2 as shown in FIG. ing. For this reason, the engine 2 can achieve compactness not only in the width direction but also in the front-rear direction and the vertical direction.

  The driven pulley shaft 64 is disposed below the driving pulley shaft 62. Specifically, the axis P3 of the driven pulley shaft 64 is located below the plane S8.

  Further, the composite pump shaft 101 including the transmission-side pump shaft 81 is disposed behind the drive pulley shaft 62. Specifically, the axis P5 of the composite pump shaft 101 is located on the rear side of the plane S9.

  Further, the composite main shaft 100 including the drive pulley shaft 62 is rotatably supported by the upper case portion 20a that is a portion above the split surface S1 of the crankcase 20. That is, the axis P2 of the composite main shaft 100 is located above the dividing surface S1.

  Furthermore, the composite pump shaft 101 including the transmission-side pump shaft 81 is rotatably supported by the lower case portion 20b which is a portion below the dividing surface S1 of the crankcase 20. That is, the axis P5 of the composite pump shaft 101 is located below the dividing surface S1.

  As described above, the engine 2 has two shafts for connecting the crankcase 20 and the transmission case 30, that is, the composite main shaft 100 and the composite pump shaft 101, and the composite main shaft 100 is divided in its axis P2. The composite pump shaft 101 is pivotally supported so as to be positioned above the surface S1, and the composite pump shaft 101 is pivotally supported so that its axis P5 is positioned below the dividing surface S1. For this reason, in addition to the rigidity of the engine case 2a being increased, in particular, the length of the engine 2 in the width direction and the front-rear direction can be effectively reduced.

  Next, the second side surface of the engine 2 according to the present embodiment will be described with reference to FIGS. In addition, in FIGS. 9-15 and the following description, about the part similar to the example shown in the above-mentioned FIGS. 1-8, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. Moreover, illustration and description of a part of the same portion as the example shown in FIGS. 1 to 8 are omitted.

  FIG. 9 is a plan view of the motorcycle 1. The motorcycle 1 includes an engine 2 similar to that shown in FIG. 1. Further, for example, as shown in FIG. 9, a seat 5 having a front seating portion 5 a and a rear seating portion 5 b, the seat 5 A pair of left and right planes having a pair of left and right planes 12f on which the driver seated on the front seating portion 5a rests the left foot and the right foot. A footboard 12e is provided.

Further, FIG. 9 shows a line (vehicle center line) C indicating the center of the motorcycle 1 in the vehicle width direction.
1 is shown. The vehicle body center line C1 is defined so that the front wheel 3 and the rear wheel 4 (see FIG. 1) are linearly arranged so that the motorcycle 1 goes straight, and the center of the front wheel 3 in the vehicle width direction and the rear wheel. It is a straight line passing through the center in the vehicle width direction.

  FIG. 10 is a left side view of the engine case 2a. FIG. 11 is a right side view of the engine case 2a. 10 and 11 show the engine case 2a in a state in which the cover members 20c and 20d of the crankcase 20 that covers the outer side of the crankshaft 40 in the vehicle width direction are attached.

  Further, as shown in FIG. 10, the engine case 2 a is disposed across three case members of the upper case portion 20 a, the lower case portion 20 b of the crankcase 20, and the left case portion 30 b of the transmission case 30. Each of the three case members and a bracket 103 fastened and fixed by a bolt member are provided. With the bracket 103, the three case members can be more integrally coupled, and the rigidity of the engine case 2a as a whole can be more effectively increased.

  FIG. 12 is a rear view of the engine case 2a. FIG. 13 is a bottom view of the engine case 2a. FIG. 13 shows the axis P1 of the crankshaft 40, the axis P2 of the drive pulley shaft 62, the axis P3 of the driven pulley shaft 64, and the axis P4 of the output shaft 70 when the engine case 2a is viewed from below. The shaft center P5 of the transmission-side pump shaft 81 is shown.

  FIG. 14 is a cross-sectional view of the engine 2 cut along the split surface S1 of the crankcase 20 as viewed from above the split surface S1. FIG. 15 is a cross-sectional view of the engine case 2a along the line XV-XV (that is, the engine center line C2) shown in FIG. In FIG. 14, a line (engine center line) C2 indicating the center of the engine in the vehicle width direction is shown. The engine center line C2 is a line that passes through the center point of the central web pair 42b in the direction along the axis P1 of the crankshaft 40 (that is, the longitudinal direction of the crankshaft 40) and is perpendicular to the axis P1. Further, the engine center line C2 is parallel to the vehicle body center line C1 shown in FIG. 9, and is slightly shifted from the vehicle body center line in the vehicle width direction. Further, in FIG. 14, the mating surface 20 g to be joined to the upper case portion 20 among the lower case portion 20 of the crankcase 20 is shown exposed.

  The engine 2 according to the second aspect includes a transmission 60 having a drive pulley 61 and a driven pulley 63 around which a metal V-belt 65 is wound (see FIG. 5), as in the above example. As shown in FIGS. 10 and 11, the crankshaft 40, the drive pulley shaft 62, the driven pulley shaft 64, the output shaft 70, and the transmission-side pump shaft 81 are provided in parallel to each other.

  The drive pulley shaft 62 and the clutch shaft 53 are coaxially connected to constitute the composite main shaft 100, and the transmission side pump shaft 81 and the crankcase side pump shaft 85 are coaxially connected to constitute the composite pump shaft 101. is doing. 10 also shows a shaft 86a of an intermediate gear 86 (see FIG. 5) that connects the crankshaft 40 and the composite pump shaft 101.

  The engine 2 includes a crankcase oil pan 110 that receives oil supplied to the crankshaft 40 and a transmission that receives oil supplied to the transmission 60, as shown in FIGS. Oil pan 140.

  The crankcase oil pan 110 and the transmission oil pan 140 are formed separately from each other. That is, the crankcase oil pan 110 is provided so as to close an opening (not shown) formed at the lower end of the lower case portion 20b of the crankcase 20 from the lower side. On the other hand, the transmission oil pan 140 is provided so as to close the opening 30d (see FIG. 11) formed at the lower end of the left case portion 30b of the transmission case 30 from below.

  The crankcase oil pan 110 includes a crankcase oil pan 120 and an oil tank 130. The crankcase side oil pan 120 is formed in a part of the bottom portion of the crankcase 20 below the crank chamber 21 in the same manner as the crankcase side oil pan 23 in the above-described example, and stores lubricating oil. The lubricating oil flows down from the crank chamber 21 and the clutch chamber 22 in the crankcase 20 into the crankcase-side oil pan 120 by gravity.

  The crankcase-side oil pan 120 has a bottom surface 121 including a central bottom surface 121a, a left bottom surface 121b, and a right bottom surface 121c. The center bottom surface 121a is disposed on the lowermost side of the crankcase side oil pan 120 and extends flat along the horizontal plane S4. The suction portion 25a (see FIG. 15) of the strainer 25 disposed in the crankcase-side oil pan 120 is disposed above the central bottom surface 121a.

  Each of the left bottom surface 121b and the right bottom surface 121c is formed so as to be positioned upward as it is separated from the vehicle width direction center C1 to the side (that is, outside in the vehicle width direction). That is, the left bottom surface 121b is formed so as to incline upward from the left end of the center bottom surface 121a further toward the left side, and the right bottom surface 121c is further directed toward the right side from the right end of the center bottom surface 121a. And inclined upward. Further, in the bottom surface 121, the front side and rear side portions of the central bottom surface 121a are formed so as to incline upward from the front end and the rear end of the central bottom surface 121a further toward the front side and the rear side, respectively. .

  Similar to the oil tank 24 in the above-described example, the oil tank 130 is another part of the bottom of the crankcase 20 (the crankcase-side oil pan 120 adjacent to the crankcase-side oil pan 120 below the clutch chamber 22). The lubricating oil transferred from the crankcase side oil pan 120 is stored.

  The oil tank 130 has a bottom surface 131 including a center bottom surface 131a, a left bottom surface 131b, and a right bottom surface 131c. The center bottom surface 131a is disposed on the lowermost side of the oil tank 130, and extends flat along the horizontal plane S4. The suction portion 26a (see FIG. 15) of the strainer 26 disposed in the oil tank 130 is disposed above the central bottom surface 131a.

  Each of the left bottom surface 131b and the right bottom surface 131c is formed so as to be positioned upward as it is separated from the vehicle width direction center C1 to the side (that is, outside in the vehicle width direction). That is, the left bottom surface 131b is formed so as to incline upward from the left end of the center bottom surface 131a toward the left side, and the right bottom surface 131c is further directed to the right side from the right end of the center bottom surface 131a. And inclined upward. Further, in the bottom surface 131, the front side and rear side portions of the central bottom surface 131a are formed so as to incline upward from the front end and the rear end of the central bottom surface 131a further toward the front side and the rear side, respectively. .

  The transmission oil pan 140 stores oil supplied to the transmission 60 by the transmission-side oil pump 80 in the same manner as the transmission-side oil pan 38 in the above-described example. The transmission oil pan 140 has a bottom surface 141 including a central bottom surface 141a, a left bottom surface 141b, and a right bottom surface 141c. The center bottom surface 141a is disposed on the lowermost side of the transmission oil pan 140, and the lowermost surface of the bottom surface of the crankcase oil pan 110 (that is, the center bottom surface 121a of the crankcase side oil pan 120 and the oil tank). 130 extends flat above the central bottom surface 131a). The suction portion 201a of the strainer 201 disposed in the transmission oil pan 140 is disposed above the central bottom surface 141a (see FIGS. 11 to 13).

  10, 11, and 15, the horizontal plane S <b> 4 is formed on the center bottom surface 121 a of the crankcase side oil pan 120 and the center bottom surface 131 a of the oil tank 130, which are the lowermost end surfaces of the engine case 2 a. Along the extension of these bottom surfaces.

  Each of the left bottom surface 141b and the right bottom surface 141c is formed so as to be positioned upward as it is separated from the vehicle width direction center C1 to the side (that is, the vehicle width direction outside). That is, the left bottom surface 141b is formed so as to incline upward further from the left end of the center bottom surface 141a toward the left side, and the right bottom surface 141c is directed further to the right side from the right end of the center bottom surface 141a. And inclined upward. Further, in the bottom surface 141, the front side and the rear side portions of the central bottom surface 141a are formed so as to be inclined upward from the front end and the rear end of the central bottom surface 141a further toward the front side and the rear side, respectively. .

  The transmission oil pan 140 includes a first portion 142 disposed on the right side with respect to the vehicle body center line C1 along the metal belt 65, and the driven pulley 63 side of the first portion 142. A second portion 143 extending from a part to the left side with respect to the vehicle body center line C1 is formed in an L shape.

  That is, as shown in FIG. 13, the drive pulley 61, the driven pulley 63, and the metal belt 65 wound around the drive pulley 61 and the driven pulley 63 are all on the right side with respect to the vehicle body center line C1. Arranged on the side. And the 1st part 142 extended in the front-back direction among the oil pans 140 for transmissions is arrange | positioned along the metal belt 65 on the right side with respect to the vehicle width direction centerline C1.

  Further, the second portion 143 is disposed across the vehicle body center line C1. That is, the second portion 143 extends from the rear side portion of the first portion 142 in the vehicle width direction and is disposed from the right side to the left side of the vehicle body center line C1. Specifically, the second portion 143 is disposed along the output shaft 70 below the output shaft 70.

  In addition, a control device 200 that controls the supply of oil to the transmission 60 and the output shaft 70 is disposed inside the transmission oil pan 140 as in the above-described example. The control device 200 includes a valve mechanism that controls the pressure required to supply the oil stored in the transmission oil pan 140 to the transmission 60.

  As shown in FIG. 13, the control device 200 is formed in an L shape corresponding to the L shape of the transmission oil pan 140. That is, a part of the control device 200 is formed to extend in the front-rear direction in the first portion 142 of the transmission oil pan 140, and the other part of the control device 200 is formed in the second portion 143. It is formed to extend in the vehicle width direction.

  On the other hand, the crankcase oil pan 110 has a third portion 111 (a part on the front side of the crankcase side oil pan 120) arranged along the longitudinal direction of the crankshaft 40 and a transmission for the transmission in the vehicle width direction. The oil pan 140 is formed in an L shape having a fourth portion 112 (a part on the rear side of the crankcase-side oil pan 120 and the oil tank 130) arranged at a position aligned with the first portion 142 of the oil pan 140. Yes.

  That is, the third portion 111 is constituted by a front side portion of the crank side oil pan 120 from the rear end of the central bottom surface 121a. The third portion 111 extends in the vehicle width direction from the side of the vehicle body center line C1 to the right side on the front side of the first portion 142 and the second portion 143 of the transmission oil pan 140. Yes.

  Further, the fourth portion 112 includes a portion on the rear side of the crank-side oil pan 120 from the rear end of the center bottom surface 121a and an oil tank 130. The fourth portion 112 is on the left side of the first portion 142 of the transmission oil pan 140 and on the front side of the second portion 143, from the left side to the right side with respect to the vehicle body center line C1. , Extending in the vehicle width direction.

  That is, the crank-side oil pan 120 itself is formed in an L shape, and the crankcase oil pan 110 formed by connecting the crank-side oil pan 120 and the oil tank 130 is also formed in an L shape as a whole. Has been.

  Thus, a part of the crankcase oil pan 110 and a part of the transmission oil pan 140 are arranged in parallel on the crankshaft 40 side and the drive pulley shaft 62 side, respectively. That is, for example, the entire crankcase oil pan 110 and the second portion 143 of the transmission oil pan 140 are arranged in parallel on the crankshaft 40 side and the drive pulley shaft 62 side in the front-rear direction, respectively. ing.

  The crankcase oil pan 110 and the transmission oil pan 140 are formed in L shapes corresponding to each other. That is, as shown in FIG. 13, the crankcase oil pan 110 and the transmission oil pan 140 are formed in an L shape so as to mesh with each other below the engine case 2a. Specifically, the fourth portion 112 of the crankcase oil pan 110 and the first portion 112 of the transmission oil pan 140 are arranged so as to overlap (overlap) in the vehicle width direction. Therefore, the capacity of both the crankcase oil pan 110 and the transmission oil pan 140 can be efficiently secured in a limited space.

  Further, as described above, the left end of the crankshaft 40 is covered with the cover member 20c disposed on the left side surface of the crankcase 20, and the right end of the crankshaft 40 is covered with the right side surface of the crankcase 20. The cover member 20d is covered (see FIG. 5). The length of the crankcase oil pan 110 in the vehicle width direction and the length of the transmission oil pan 140 in the vehicle width direction are both the left end of the left cover member 20c of the crankcase 20 in the vehicle width direction. A plane S10 perpendicular to the axis P1 of the crankshaft 40 and a plane S11 perpendicular to the axis P1 of the crankshaft 40 passing through the right end in the vehicle width direction of the right cover member 20d of the crankcase 20 It is in the range of the length between. That is, the width of the crankcase oil pan 110 (the length from the left end to the right end of the crankcase oil pan 110) and the width of the transmission oil pan 140 (the left end of the transmission oil pan 140). To the right end) is within the range of the width of the engine case 2a.

  The transmission oil pan 140 is disposed below the transmission case 30, and the rear end 144 of the transmission oil pan 140 is behind the portion of the transmission case 30 that covers the rear of the driven pulley 63. It is arranged further rearward than the end 30h. That is, as described above, the transmission case 30 includes three case portions 30a, 30b, and 30c that can be divided from each other by dividing surfaces S2 and S3 (see FIG. 5) perpendicular to the axis P2 of the drive pulley shaft 62. It is configured. The transmission oil pan 140 is formed at the lower end of the bottom portion of the left case portion 30b among the three case members 30a, 30b, and 30c constituting the transmission case 30, as shown in FIG. The opening 30d is provided so as to be closed from below.

  Here, as shown in FIGS. 10 and 11, the lower end portion 30 i of the left case portion 30 b is positioned further to the rear side than the rear end 30 h of the portion whose rear end covers the rear of the driven pulley 63. It is formed to project to the rear side. The transmission oil pan 140 is provided so as to block the lower end portion 30i of the left case portion 30b protruding rearward from the lower side. As a result, the rear end 144 of the transmission oil pan 140 is disposed further rearward than the rear end 30 h of the portion of the transmission case 30 that covers the rear of the driven pulley 63.

  Further, the width of the transmission oil pan 140 in the longitudinal direction of the crankshaft 40 is larger than the width of the crankcase oil pan 110 in the longitudinal direction, and the bottom surface 141 of the transmission oil pan 140 corresponds to the crankcase. The oil pan 110 is disposed above the bottom surface (that is, the bottom surface 121 of the crankcase-side oil pan 120 and the bottom surface 131 of the oil tank 130). On the other hand, the engine 2 is a multi-cylinder engine having three cylinders, and three exhaust pipes 2d, 2e, and 2f extend from the cylinder portion 2b. That is, as shown in FIGS. 10 and 11, the three exhaust pipes 2d, 2e, and 2f all extend downward and rearward from the front side surface of the cylinder portion 2b.

  As shown in FIG. 10, the two left exhaust pipes 2d and 2e extend rearward on the left side of the crankcase 20, and the one right exhaust pipe 2f is shown in FIG. In addition, the crankcase 20 extends rearward on the right side.

  In the engine 2, the two left exhaust pipes 2d and 2e are arranged on the left side of the crankcase oil pan 110 with a reduced width, and the one right exhaust pipe 2f is connected to the crankcase. It can be placed on the right side of the oil pan. Further, in the engine 2, these three exhaust pipes 2d, 2e, and 2f can be collectively arranged below the transmission oil pan 140 with a reduced height.

  As shown in FIGS. 14 and 15, the engine 2 includes an oil unit 300 having an oil filter 300 a that filters oil and an oil cooler 300 b that cools oil at a front end portion of the crankcase 20. ing. In addition, it is preferable to arrange the oil unit 300 so as to be exposed on the front side of the vehicle body from the viewpoints of maintainability of the oil unit 300 and cooling performance of the oil cooler 300b.

  The oil filter 300a and the oil cooler 300b are each formed as a cylindrical member. Then, the circular end surface on the rear side of the oil filter 300a and the circular end surface on the front side of the oil cooler 300b are joined together to form an integral oil unit 300.

  An oil passage member 301 is inserted into the oil unit 300. The hollow portion formed in the oil passage member 301 forms an oil passage 28b similar to that shown in FIG.

  The oil unit 300 is arranged to be located rearward and upward as much as possible. That is, first, as shown in FIG. 14, in the front end portion of the crankcase 20, the central portion 20 f in the direction along the axis P <b> 1 of the crankshaft 40 is formed to be recessed rearward.

  The oil unit 300 is provided so as to protrude forward from the center portion 20f of the crankcase 20 that is recessed toward the rear side. That is, the oil unit 300 is disposed in front of the cylinder in the center in the vehicle width direction among the three cylinders included in the engine 2. Specifically, as shown in FIG. 14, the oil unit 300 has a center in the direction along the axis P <b> 1 of the crankshaft 40 among the three crank web pairs 42 a, 42 b, 42 c provided on the crankshaft 40. Is disposed in front of a pair of crank webs 42b.

  The position of the oil unit 300 in the longitudinal direction of the crankshaft 40 is not limited to the range of the cylinder disposed in the center in the longitudinal direction when the engine 2 is a multi-cylinder engine having three or more cylinders. For example, it can be arranged within a range of one or a plurality of cylinders other than the cylinders at both ends in the longitudinal direction.

  Further, as shown in FIG. 14, the engine 2 includes a balancer 47 in front of the crankshaft 40. That is, the balancer 47 is arranged in front of the crankshaft 40 in parallel with the crankshaft so that the shaft center P6 of the shaft 47b is located on the split surface S1 of the crankcase 20, as shown in FIG. ing.

  The balancer shaft 47b is rotatably supported by the crankcase 20. That is, as shown in FIG. 14, the left end portion of the balancer shaft 47b is pivotally supported by the left side shaft support portion 47a of the crankcase 20 via a needle bearing, and the right end portion thereof is a ball bearing. And is pivotally supported by a shaft support portion 47a on the right side of the crankcase 20.

  The balancer 47 has a pair of left and right balancer weights 47c and 47d provided at both ends of the balancer shaft 47b. That is, as shown in FIG. 14, the left balancer weight 47c is provided adjacent to the right side of the left side shaft support portion 47a, and the right balancer weight 47d is provided on the right side of the right side shaft support portion 47a. It is provided adjacent to.

  A gear for driving the balancer shaft 47b in conjunction with the crankshaft 40 at a position adjacent to the left side of the right balancer weight 47d via the right side shaft support portion 47a of the balancer shaft 47b. 47e is provided. The gear e meshes with a gear formed on the outer periphery of the right crank web constituting the crank web pair 42c on the right side of the crankshaft 40. The balancer shaft 47b is connected to the crankshaft 40 through the gear 47e, and is driven by the rotation of the crankshaft 40.

  The left balancer weight 47c and the right balancer weight 47d are disposed on the left side and the right side with respect to the oil unit 300, respectively. That is, as shown in FIG. 14, the left balancer weight 47c and the right balancer weight 47d are disposed on the left side and the right side of the center portion 20f of the crankcase 20, respectively.

  The oil cooler 300b, which is the rear side portion of the oil unit 300, and the left balancer weight 47c and the right balancer weight 47d are arranged in series so as to overlap in the longitudinal direction of the crankshaft 40. With such a configuration, in the engine 2, the oil unit 300 can be disposed on the rear side while the balancer 47 is provided in front of the crankshaft 40.

  Further, as shown in FIG. 15, the oil unit 300 extends while inclining downward toward the front. On the other hand, the split surface S1 of the crankcase 20 also extends while inclining downward toward the front. An angle A1 formed by the dividing plane S1 and the horizontal plane S4 is suppressed within a predetermined range, for example, a range of 25 degrees to 45 degrees.

  On the other hand, a line that passes through the center of the mounting surface S14 between the oil filter 300a and the oil cooler 300b and is perpendicular to the mounting surface S14 (that is, the center line C3 of the oil unit 300) is directed forward. The case 20 is inclined and extends away from the dividing surface S1. Specifically, an angle A2 formed by the oil unit center line C3 and a plane S15 passing through the center of the attachment surface S14 and parallel to the dividing surface S1 can be about 10 degrees.

  As a result, as shown in FIG. 15, the oil unit 300 can be arranged such that its lower end is located above the lower end of the crankcase oil pan 110 (that is, the horizontal plane S4 shown in FIG. 15). Thus, in the engine 2, the oil unit 300 can be disposed at a position close to the crankshaft 40.

  In the engine 2, the cylinder portion 2 b is provided so as to be inclined forward with respect to the split surface S <b> 1 of the crankcase 20. That is, as shown in FIG. 15, a line (cylinder center line) D1 along the longitudinal direction of the cylinder portion 2b (the direction in which the piston reciprocates) is greater than a line D2 perpendicular to the dividing surface S1 of the crankcase 20 Is also tilted forward. Specifically, an angle A3 formed by the cylinder center line D1 and the perpendicular line D2 can be set to 25 degrees or more, for example. As a result, in the engine 2, the angle A4 formed by the cylinder center line D1 and the line D3 perpendicular to the horizontal plane S4 can be 60 degrees or more.

  Further, as shown in FIG. 15, the balancer shaft 47 b is disposed above the horizontal plane S <b> 12 passing through the lower end of the range Q <b> 1 of the crankshaft 40 including the crank web 42. Further, the range Q2 of the pair of left and right balancer weights 47c and 47d is disposed below the horizontal plane S13 passing through the axis P1 of the crankshaft 40.

  With such a configuration, the engine 2 includes the crankcase 20 with the dividing surface S1 inclined, and the height of the cylinder portion 2b is increased while the balancer shaft 47b is disposed in front of the crankshaft 40 on the dividing surface S1. In addition, the oil unit 300 is arranged on the upper side, and the overall vertical length can be effectively reduced.

  Further, as shown in FIG. 15, in the engine 2, a sufficient clearance is ensured between the level surface L <b> 1 of the oil stored in the crankcase side oil pan 120 and the balancer 47. For this reason, it is possible to effectively avoid the balancer weights 47c and 47d from being immersed in the oil in the crankcase-side oil pan 120, and to effectively reduce the loss of driving force. FIG. 15 also shows an oil level surface L2 in the oil tank 130.

  In the engine 2, the crankshaft 40, the composite main shaft 100, the driven pulley shaft 64, the output shaft 70, and the composite pump shaft 101 are formed separately from each other and arranged in parallel to each other. Thereby, the length of the engine 2 in the vehicle width direction can be reduced, and the engine 2 can be made compact.

  Further, the engine according to the present invention can be an engine having one or a plurality of cylinders, preferably an engine having a plurality of cylinders arranged in series, and particularly preferably in series. It can be set as the engine provided with the three or more cylinders arrange | positioned. Further, at least a part of the transmission-side oil pump 80 and the crankcase-side oil pump 82 (scavenge pump 83, feed pump 84) is not limited to the trochoid pump, and may be other types of oil pumps.

  Thus, according to the present invention, a compact engine can be realized. Therefore, the engine according to the present invention is suitable for a straddle-type vehicle having a limited space in which the engine can be disposed, such as a motorcycle.

  As described above, the engine 2 includes the crankshaft 40, the transmission 60 having the drive pulley 61 and the driven pulley 63, and the first oil pan (the crankcase oil pan 110) that receives oil supplied to the crankshaft 40. And a first oil pan (crankcase oil pan 110) and a separate second oil pan (transmission oil pan 140) that receive oil supplied to the transmission 60, and The crankshaft 40 extends in the vehicle width direction of the saddle riding type vehicle body (the motorcycle 1) on which the engine 2 is mounted, and a drive pulley shaft 62 that drives the drive pulley 61 is disposed in parallel with the crankshaft 40. At least a portion of the first oil pan (crankcase oil pan 110) and at least a portion of the second oil pan (transmission oil pan 140). A part of the second oil pan (transmission oil pan 140) is disposed in parallel with the crankshaft 40 side and the drive pulley shaft 62 side, and the second oil pan (transmission oil pan 140) extends over the vehicle width direction center C1 ( A first portion 142) of the transmission oil pan 140; Thus, the capacity of the second oil pan (transmission oil pan 140) can be sufficiently secured while suppressing the engine 2 from being enlarged in the vehicle width direction. That is, by arranging the crankshaft 40 and the drive pulley shaft 62 in parallel, the width of the engine 2 is reduced, and the portion (first first) straddling the center in the vehicle width direction on the second oil pan (transmission oil pan 140). By providing the portion 142), the engine 2 can be made compact and the transmission oil pan (transmission oil pan 140) can be secured at the same time.

  In the engine 2, a belt (metal belt 65) wound around the drive pulley 61 and the driven pulley 63 is disposed on one side with respect to the center in the vehicle width direction, and a second oil pan (for transmission) The oil pan 140) includes a first portion 142 disposed on the one side with respect to the center in the vehicle width direction along the belt (metal belt 65), and the driven pulley of the first portion 142. A second portion 143 extending from a part on the 63 side to the other side with respect to the center in the vehicle width direction is formed in an L shape. As a result, the engine 2 can be made compact and the capacity of the second oil pan (transmission oil pan 140) can be secured at the same time, while the other parts of the engine 2 in the straddle-type vehicle (motorcycle 1) Space for arranging members other than the engine 2 can be secured. Here, as for the position of the transmission 60, at least the belt (metal belt 65) may be disposed on one side with respect to the center in the vehicle width direction, but in addition to the belt (metal belt 65). At least one of the driving pulley 61 or the driven pulley 63 may be disposed on the one side, and further, all of the belt (the metal belt 65), the driving pulley 61, and the driven pulley 63 may be disposed on the one side. Good. For example, when the drive pulley shaft 62 is disposed in parallel with the crankshaft 40 and the entire drive pulley 61 is disposed on one side with respect to the vehicle width direction, the crankshaft 40 is moved to the drive pulley shaft 62. Since a power transmission member such as a gear for transmitting power (gear 51b of the clutch upstream portion 51, gear 42a of the crankshaft 40) or a chain can be arranged on the other side with respect to the vehicle width direction, the width of the engine 2 is effectively reduced. This can reduce the size of the engine 2. Further, for example, when the drive pulley 61, the driven pulley 63, and the belt (metal belt 65) are all disposed on one side with respect to the center in the vehicle width direction, the power is transferred from the crankshaft 40 to the drive pulley shaft 62. A power transmission member such as a gear (gear 51b of the clutch upstream portion 51, a gear 42a of the crankshaft 40) or a chain, or a power transmission member for transmitting power downstream of the driven pulley 63 in the driving force transmission path Since the output shaft left portion 70b and the connecting shaft 71 can be arranged on the other side with respect to the vehicle width direction, the width of the engine 2 can be effectively reduced and the engine 2 can be made compact.

  In the engine 2, the first oil pan (crankcase oil pan 110) includes a third portion (a part of the crankcase-side oil pan 120) disposed along the longitudinal direction of the crankshaft 40; A fourth part (another part of the crankcase-side oil pan 120 and the oil tank 130) arranged at a position aligned with the first part 142 of the second oil pan (transmission oil pan 140) in the vehicle width direction. Are formed in an L shape. As a result, the first oil pan (crankcase oil pan 110) and the second oil pan (transmission oil pan 140) can be efficiently arranged in a limited space. Sufficient capacity can be secured.

  In the engine 2, the bottom surface 141 of the second oil pan (transmission oil pan 140) is a portion (the left bottom surface 141 b and the right bottom surface) that are formed so as to be positioned upward as the distance from the center in the vehicle width direction increases. 141c). Thus, for example, when the engine 2 is applied to a straddle-type vehicle (motorcycle 1 or some straddle-type four-wheeled vehicle) that may tilt the vehicle body when driving or stopping, a sufficient bank angle is obtained. Can be secured. That is, even when the vehicle body is tilted, contact between the bottom surface 141 of the second oil pan (transmission oil pan 140) and the traveling surface can be effectively avoided. Even when the engine 2 is applied to a straddle-type vehicle in which the bank angle does not become a problem, for example, members extending in the front-rear direction of the vehicle body (exhaust pipes 2d, 2e, 2f, and the vehicle body constituting the skeleton of the vehicle body) Frame) can be disposed in the vicinity of the bottom surface 141 of the second oil pan (transmission oil pan 140), so that the vertical length of a part of the vehicle body disposed around the engine 2 is An increase due to the arrangement can be effectively avoided. Of the bottom surface 141 of the (transmission oil pan 140), the portions (the left bottom surface 141b and the right bottom surface 141c) formed so as to be located upward as they move away from the center in the vehicle width direction are the center in the vehicle width direction. However, it is not limited to this as long as the bank angle can be secured, for example, gradually upward as it moves away from the center in the vehicle width direction. You may form in steps so that it may be located.

  In the engine 2, one end and the other end in the longitudinal direction of the crankshaft 40 are covered with a case (crankcase 20), and a first oil pan (crankcase oil pan 110) and a second oil pan are covered. The length of the (transmission oil pan 140) in the vehicle width direction passes through the one end of the case (crankcase 20) (the outer end in the vehicle width direction of the cover member 20c) of the crankshaft 40. The surface S10 perpendicular to the axis P1 and the other end of the case (crankcase 20) (the outer end in the vehicle width direction of the cover member 20d) pass through the axis P1 of the crankshaft 40. Is within the range of the length W0 between the vertical surface S11. Thereby, the width (W1) of the first oil pan (crankcase oil pan 110) and the width W2 of the second oil pan (transmission oil pan 140) are both the case (engine case 2a) constituting the outer shell of the engine 2. ) In the range of the width W0, in particular, the width of the engine 2 can be effectively reduced.

  The engine 2 further includes a transmission case 30 that houses the transmission 60, and the second oil pan (transmission oil pan 140) is disposed below the transmission case 30, and the second oil pan The rear end 144 of the pan (transmission oil pan 140) is disposed further rearward than the rear end 30h of the portion of the transmission case 30 that covers the rear of the driven pulley 63. Thus, the capacity of the transmission oil pan (transmission oil pan 140) can be effectively secured.

  The engine 2 includes a plurality of cylinders, and the width W2 of the second oil pan (transmission oil pan 140) in the longitudinal direction of the crankshaft 40 is the first oil pan (crankcase oil in the longitudinal direction). The bottom surface 141 of the second oil pan (transmission oil pan 140) is larger than the width W1 of the pan 110) and the bottom surface (crankcase side oil pan 120) of the first oil pan (crankcase oil pan 110). Are disposed above the bottom surface 121 and the bottom surface 131) of the oil tank 130. Thus, first, the second oil pan (crankcase oil pan 110) secures a large height while reducing the width W1, and the second oil pan (transmission oil pan 140) secures a large width W2. While reducing the height, the capacity of both these oil pans can be efficiently secured. Further, in addition to this, a plurality of exhausts extending to the side of the first oil pan (crankcase oil pan 110) and below the second oil pan (transmission oil pan 140) corresponding to a plurality of cylinders. Since the pipes 2d, 2e, and 2f can be arranged, it is possible to provide a compact engine 2 that is suitable for a saddle-ride type vehicle (motorcycle 1) whose width and height are limited. That is, a part of exhaust pipes 2d, 2e, and 2f (exhaust pipes 2d and 2e) and the other part (exhaust pipe 2f) extending from the front part of the engine 2 to the rear side of the engine case 2a. ) Can be disposed on the left side and the right side of the first oil pan (crankcase oil pan 110), respectively, and the plurality of exhaust pipes 2d, 2e, and 2f can be joined downstream. The plurality of exhaust pipes 2d, 2e, and 2f can be collectively arranged below the second oil pan (transmission oil pan 140).

  The engine 2 further includes a transmission case 30 that houses the transmission 60, and the transmission case 30 is a surface (divided surface S <b> 2, divided surface S <b> 3) that is perpendicular to the axis P <b> 2 of the drive pulley shaft 62. The second oil pan (transmission oil pan 140) includes a plurality of case parts (right case part 30a, left case part 30b, left end case part 30c) that can be divided from each other. The case 30a, the left case 30b, and the left end case 30c) are provided so as to close the opening 30d formed in one (the left case 30b). As a result, the assembly of the engine 2 can be improved, the manufacture of the engine 2 can be facilitated, and oil leakage from the second oil pan (transmission oil pan 140) can be reliably avoided. is made of.

1 is an example of a left side view of a motorcycle according to an embodiment of the present invention. It is an example of the left view of the engine case which concerns on one Embodiment of this invention. It is an example of the right view of the engine case which concerns on one Embodiment of this invention. It is another example of the right view of the engine case which concerns on one Embodiment of this invention. It is sectional drawing of the engine along the VV line shown in FIG. It is sectional drawing of the engine along the VI-VI line shown in FIGS. It is sectional drawing of the engine along the VII-VII line shown in FIG. It is explanatory drawing which shows the relative positional relationship of the axis | shaft in the left side view of the engine which concerns on one Embodiment of this invention. 1 is an example of a plan view of a motorcycle according to an embodiment of the present invention. It is another example of the left view of the engine case which concerns on one Embodiment of this invention. It is another example of the right view of the engine case which concerns on one Embodiment of this invention. It is an example of the rear view of the engine case which concerns on one Embodiment of this invention. It is an example of the bottom view of the engine case which concerns on one Embodiment of this invention. It is sectional drawing along the crankcase division | segmentation surface of the engine which concerns on one Embodiment of this invention. It is sectional drawing of the engine case along the XV-XV line | wire shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Motorcycle, 2 engine, 2a engine case, 2b cylinder part, 3 front wheel, 4 rear wheel, 5 seat, 6 handle, 7 front fork, 8 driving force transmission device, 9 drive shaft, 10 silencer, 11 pivot shaft, 12 body cover, 13 cylinder, 14 cylinder head, 15 cover, 20 crank case, 20a upper case portion, 20b lower case portion, 21 crank chamber, 22 clutch chamber, 22a clutch left shaft support portion, 22b clutch middle shaft support portion, 22c clutch right Shaft support part, 23 Crankcase side oil pan, 24 Oil tank, 29a Right pump support part, 29b Left pump support part, 29c Crankcase side pump left shaft support part, 29d Crankcase side pump right insertion part, 30 Transmission case, 30a Right case part, 30b Case portion, 30c Left end case portion, 30d Opening, 31 Transmission chamber, 32 Output chamber, 33a Drive side pulley right shaft support portion, 33b Drive side pulley left shaft support portion, 34a Drive side pulley right shaft support portion, 34b Drive side pulley Left shaft support portion, 37 Transmission side pump support portion, 37c Transmission side pump insertion portion, 38 Transmission side oil pan, 40 Crank shaft, 50 Clutch, 53 Clutch shaft, 60 Transmission, 61 Drive pulley, 62 Drive pulley shaft 63, driven pulley, 64 driven pulley shaft, 65 metal belt, 70 output shaft, 71 connecting shaft, 80 transmission side oil pump, 81 transmission side pump shaft, 82 crankcase side oil pump, 85 crankcase side pump shaft 85a Crankcase side oil pump shaft, 85b Cooling water pump shaft, 86 Intermediate gear, 88 Engagement member , 90 Tightening hole, 91 bolt member, 100 composite main shaft, 101 composite pump shaft, 110 crankcase oil pan, 120 crankcase side oil pan, 130 oil tank, 140 transmission oil pan, 141 bottom surface, 200 control apparatus.

Claims (9)

A crankshaft,
A transmission having a drive pulley and a driven pulley;
A first oil pan that receives oil supplied to the crankshaft;
Receiving the oil supplied to the transmission, a second oil pan separate from the first oil pan;
An engine with
The crankshaft extends in a vehicle width direction of a saddle riding type vehicle body on which the engine is mounted,
A drive pulley shaft for driving the drive pulley is disposed in parallel with the crankshaft;
At least a part of the first oil pan and at least a part of the second oil pan are respectively arranged in parallel on the crankshaft side and the drive pulley shaft side,
The engine, wherein the second oil pan has a portion straddling the center in the vehicle width direction. The belt wound around the drive pulley and the driven pulley is disposed on one side with respect to the vehicle width direction center,
The second oil pan is
A first portion disposed on the one side with respect to the vehicle width direction center along the belt;
A second portion extending from a part of the driven pulley side to the other side with respect to the vehicle width direction center of the first part;
The engine according to claim 1, wherein the engine has an L shape. The first oil pan is disposed at a position aligned with the third portion disposed along the longitudinal direction of the crankshaft and the first portion of the second oil pan in the vehicle width direction. The engine according to claim 2, wherein the engine is formed in an L shape. 2. The engine according to claim 1, wherein a bottom surface of the second oil pan has a portion formed so as to be positioned upward as the distance from the center in the vehicle width direction increases. One end and the other end in the longitudinal direction of the crankshaft are covered with a case,
The lengths of the first oil pan and the second oil pan in the vehicle width direction pass through end portions on the one side of the case and are perpendicular to the axis of the crankshaft, and the length of the case. 2. The engine according to claim 1, wherein the engine is within a length range between a surface passing through the other end and perpendicular to the axis of the crankshaft. A transmission case that houses the transmission;
The second oil pan is disposed below the transmission case,
The engine according to claim 1, wherein a rear end of the second oil pan is disposed further rearward than a rear end of a portion of the transmission case that covers the rear of the driven pulley. With multiple cylinders,
The width of the second oil pan in the longitudinal direction of the crankshaft is larger than the width of the first oil pan in the longitudinal direction, and the bottom surface of the second oil pan is above the bottom surface of the first oil pan. The engine according to claim 1, wherein the engine is arranged. A transmission case that houses the transmission;
The transmission case includes a plurality of case portions that can be divided from each other in a plane perpendicular to the axis of the drive pulley shaft,
The engine according to claim 1, wherein the second oil pan is provided to close an opening formed in one of the plurality of case portions. A straddle-type vehicle comprising the engine according to claim 1.

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