JP4879579B2 - Power unit for vehicle - Google Patents

Description

  The present invention includes an engine and a power transmission device, and is mounted on a vehicle. The power transmission device shifts the output of the crankshaft of the engine, and a gear reducer that reduces the output of the transmission. The gear reducer extends parallel to the axis of the crankshaft and is rotatably supported by the crankcase of the engine and connected to the output side of the transmission, and extends parallel to the driveshaft. The present invention relates to a vehicle power unit provided between a crankshaft and a driven shaft that is rotatably supported by a crankcase.

In a motorcycle, the output of a V-belt transmission that continuously changes the output of an engine is reduced by a gear reducer that reduces the speed in three stages and transmitted to the rear wheels. Known in Document 2 and disclosed in Patent Document 1, a drive shaft and a driven shaft are provided between a drive shaft that is an output shaft of a V-belt transmission and a driven shaft that is an axle of a rear wheel. An intermediate shaft having a parallel axis is arranged, and a gear reduction device is configured to perform primary deceleration between the drive shaft and the intermediate shaft and secondary deceleration between the intermediate shaft and the driven shaft. Moreover, in what was disclosed by patent document 2, the intermediate shaft which has an axis parallel to a drive shaft and a driven shaft is arrange | positioned to the side of the drive shaft and driven shaft which can rotate the same axis line, and a drive shaft and an intermediate shaft The gear reducer is configured to perform primary deceleration between the intermediate shaft and the driven shaft to perform secondary deceleration.
Japanese Patent Publication No.7-115596 Japanese Patent Publication No. 4-11429

  However, when trying to set a large reduction ratio between the drive shaft and the driven shaft, in the gear reducer disclosed in Patent Document 1, the distance between the shafts is increased and the outer diameter of the drive gear is set large. This increases the cost and weight, and also increases the length of the gear reducer in the direction perpendicular to the axes of the drive shaft and the driven shaft.

  Moreover, in what was disclosed by patent document 2, although the length of the gear reducer in the direction orthogonal to the axis line of a drive shaft and a driven shaft can be comprised compactly, the deceleration between a drive shaft and a driven shaft is possible. It is difficult to set a large ratio, and the structure is complicated because the driven shaft is supported by the drive shaft so as to be relatively rotatable.

  The present invention has been made in view of such circumstances, and sets a large reduction ratio while avoiding an increase in length, cost and weight in a direction orthogonal to the axis of the drive shaft and the driven shaft moving shaft. It is an object of the present invention to provide a gear reducer having a simple structure that can be made.

In order to achieve the above object, an invention according to claim 1 is mounted on a vehicle having an engine having a crankshaft axis extending in the vehicle width direction and a power transmission device, and the power transmission device is connected to the crank of the engine. with a V-belt type continuously variable transmission for shifting the output of the shaft, and a gear reducer for reducing the output of the V-belt type continuously variable transmission, the gear reducer is extending parallel to the axis of the crankshaft A drive shaft that is rotatably supported by the engine crankcase and connected to the output side of the V-belt continuously variable transmission, and extends parallel to the drive shaft in the longitudinal direction of the vehicle and rotates to the crankcase. In a vehicular power unit that is freely supported and is provided between a driven shaft that interlocks with a wheel, the gear reducer is supported by a primary reduction drive gear fixed to the drive shaft and a relative rotation on the driven shaft. A primary reduction driven gear meshed with the primary reduction drive gear, a secondary reduction drive gear formed integrally with the primary reduction driven gear, and the secondary reduction drive supported on the drive shaft so as to be relatively rotatable. A secondary reduction driven gear meshed with the gear, a tertiary reduction drive gear formed integrally with the secondary reduction driven gear, and a tertiary reduction driven gear fixed to the driven shaft and meshed with the tertiary reduction drive gear. wherein the transmission case for housing the V-belt type continuously variable transmission with a crankcase are coupled together, between the both cases, to face the part of the one end portion and the drive shaft of the driven shaft A kick shaft having an axis extending parallel to the axis of the crankshaft is rotatably supported across the two cases, and the kick shaft is attached to the outside of the kick pedal. A kick drive gear disposed inward of the outer end surface of the transmission case in the axial direction of the crankshaft and rotatably supported by the kick shaft; and the kick drive gear disposed in the gap And a first idle gear that is rotatably supported by the one end portion of the driven shaft , and a first idle gear that is disposed in the gap and meshes with the first idle gear and is rotatably supported by the drive shaft. 2 idle gears, a third idle gear integrally formed on the side of the transmission case side of the second idle gear and disposed in the gap, and disposed in the gap and meshing with the third idle gear And the kick shaft and the crankshaft are linked and connected via a drive gear fixed to the end of the crankshaft to constitute a part of the V-belt continuously variable transmission and the drive Do not attach to the shaft A centrifugal clutch capable of connecting / disconnecting between the driven pulley and the drive shaft is provided on the drive shaft adjacent to the crankcase side of the driven pulley and is projected on a plane orthogonal to the axis of the drive shaft. The driven shaft is disposed in the centrifugal clutch, and the centrifugal clutch includes a clutch housing formed in a tapered bowl shape on the crankcase side and fixed to the drive shaft, and the clutch of the transmission case A portion facing the housing is formed in a bowl shape along the clutch housing, and a portion of the third idle gear facing the clutch housing across the transmission case faces the gap of the driven shaft. so as to avoid the one end, it is formed in a bowl shape along the clutch housing and said Rukoto.

The invention according to claim 2, in addition to the configuration of the invention according to claim 1, in the projection view to a plane perpendicular to the axis of the front SL drive shaft, the driven shaft is disposed in the front Kido Ribunpuri It is characterized by that.

The invention according to claim 3 is the primary reduction drive gear and the primary reduction driven gear, the secondary reduction drive gear and the secondary reduction driven gear, and the tertiary, in addition to the configuration of the invention according to claim 1 or 2. The reduction ratios of the reduction drive gear and the tertiary reduction driven gear are all set to be the same.

Invention of claim 4, in addition to the configuration of the invention according to any one of claims 1 to 3, wherein the primary reduction driving gear, said drive shaft in the axial direction on both sides of the secondary reduction driven gear and tertiary reduction drive gear Is rotatably supported by a crankcase of an engine via first and second bearings, and the driven shaft is connected to the driven shaft on one side in the axial direction of the primary reduction driven gear, the secondary reduction driven gear, and the tertiary reduction driven gear. The primary reduction driven gear, the secondary reduction driven gear, and the tertiary reduction driven gear are rotatably supported on the crankcase via a third bearing disposed at substantially the same position as the first bearing in a direction along the axis of the primary reduction driven gear. The driven shaft is rotatably supported on the crankcase via a fourth bearing disposed at substantially the same position as the second bearing in a direction along the axis of the driven shaft on the other side in the axial direction. And

Furthermore, in the invention according to claim 5 , in addition to the configuration of the invention according to any one of claims 1 to 4 , the primary reduction driven gear and the secondary reduction drive gear that are integrally formed are cylindrical first. The secondary reduction driven gear and the tertiary reduction drive gear, which are rotatably supported on the driven shaft via a single metal bearing and are integrally formed, rotate to the drive shaft via a cylindrical second metal bearing. The first and second metal bearings are freely supported. Lubricating oil holes having an inner end communicating with an oil passage provided coaxially with the driven shaft and the drive shaft and having an outer end opened to the outer periphery are radially provided It is characterized by being provided to extend.

  The secondary shaft 54 of the embodiment corresponds to the drive shaft of the present invention, the counter shaft 83 of the embodiment corresponds to the driven shaft of the present invention, and the ball bearings 55, 56, 84, 85 of the embodiment are the first of the present invention. It corresponds to each of the first to fourth bearings.

  According to the first aspect of the present invention, the output of the transmission input to the drive shaft is attached to the driven shaft, the primary reduction drive gear, the secondary reduction driven gear and the tertiary reduction drive gear attached to the drive shaft. The primary reduction driven gear, the secondary reduction drive gear, and the tertiary reduction driven gear are decelerated in three stages and transmitted to the driven shaft, thereby reducing the distance between the shafts and reducing the outer diameter of each gear. This makes it possible to obtain a large reduction ratio, shorten the length of the gear reducer in the direction orthogonal to the axis of the drive shaft and the driven shaft, and avoid an increase in cost and weight. In addition, the drive shaft and the driven shaft are arranged so as to be rotatable in parallel with each other, and the structure of the gear reducer is not complicated.

Also, in the projection drawing showing the plane perpendicular to the axis of the drive shaft, it is made more compact power unit while by placing the drive shaft and the driven shaft in the centrifugal clutch to easily secure the space for the gear reducer Can do.

According to the second aspect of the present invention, the drive shaft and the driven shaft are arranged in the driven pulley of the V-belt type transmission on the projection onto the plane orthogonal to the axis of the drive shaft, and the arrangement space for the gear reducer The power unit can be made compact while ensuring the above.

According to the third aspect of the present invention, the primary reduction driven gear and the secondary reduction drive gear that are integrally formed, and the secondary reduction driven gear and the tertiary reduction drive gear that are integrally formed are formed in the same shape. And the number of parts can be reduced.

According to the fourth aspect of the present invention, it is possible to simplify the processing applied to the crankcase for rotatably supporting the drive shaft and the driven shaft, and to support the drive shaft and the driven shaft by the crankcase. The surface pressure can be reduced.

Furthermore, according to the fifth aspect of the present invention, the primary reduction driven gear and the secondary reduction drive gear, which are integral with each other, and the lubrication of the secondary reduction driven gear and the tertiary reduction drive gear to the driven shaft and the support portion of the drive shaft. The structure is simplified, and oil flowing out from between the first and second metal bearings, the primary reduction driven gear and the secondary reduction drive gear, and the secondary reduction driven gear and the tertiary reduction drive gear is supplied to the meshing portion of each gear. Can be used for lubrication.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 3 show an embodiment of the present invention. FIG. 1 is a side view of a motorcycle, FIG. 2 is a side view of a power unit, and FIG. 3 is a sectional view taken along line 3-3 of FIG.

  In the following description of the embodiments, front and rear and left and right refer to directions in a state where the motorcycle is directed forward in the traveling direction.

  First, in FIG. 1, a body frame F of this motorcycle includes a head pipe 6 that supports a front fork 5 that pivotally supports a front wheel WF, a main frame 7 that extends rearwardly downward from the head pipe 6, and a rear frame. A seat rail 8 is provided that extends upward and is continuously provided at the lower portion of the main frame 7. A steering handle 9 is connected to an upper portion of the front fork 5, and a seat 10 on which a passenger sits is provided on the seat rail 8.

  In the main frame 7, a power unit P composed of an engine E and a power transmission device T that continuously shifts and decelerates the output of the engine E is arranged below the body frame F. A rear wheel WR is pivotally supported between the rear portions of a pair of swing arms 11 and 12 whose front ends are supported so as to be swingable by the power unit P. The output of the power unit P will be described later. The rear cushion 14 is provided between the swing arms 11 and 12 and the seat rail 8 through the chain transmission means 13 shown in FIG.

  Further, the front of the head pipe 6 is covered with a front top cover 15, the rear of the head pipe 6 and the front part of the main frame 7 are covered with a main frame top cover 16, and the side of the main frame 7 is a main frame side cover 17. Leg shields 18 are disposed on both sides of the main frame side cover 17 so as to cover the occupant's legs from the front, and are connected to the front top cover 15. An under cover 19 is provided continuously to cover the power unit P from the front.

  2 and 3, the engine E of the power unit P includes a crankcase 21, a cylinder block 22 coupled to the front end of the crankcase 21 in a forward inclined posture, and a cylinder head 23 coupled to the front end of the cylinder block 22. Is provided.

A crankshaft 24 having an axis extending in the left-right direction , i.e., the vehicle width direction , is rotatably supported by a crankcase 21, and a piston 26 slidably fitted into a cylinder bore 25 provided in the cylinder block 22 includes a connecting rod 27 and a crank. A spark plug 29 is attached to the cylinder head 23 and connected to the crankshaft 24 via a pin 28, and a valve mechanism 31 including a camshaft 30 is disposed.

  The crankcase 21 is formed by joining left and right case halves 21L and 21R divided into left and right on a vertical plane including the axis of the cylinder bore 25, and the crankshaft 24 is composed of the left and right case halves 21L. , 21R is rotatably penetrated.

  A drive sprocket 32 is fixed to the crankshaft 24 outside the left case half 21 </ b> L, and a driven sprocket 33 is fixed to the camshaft 30 provided in the valve mechanism 31, and the drive sprocket 32 and the driven sprocket 33 are connected to the camshaft 30. The endless timing chain 34 is wound around. Thus, the left case half 21L, the cylinder block 22 and the cylinder head 23 are provided with a chain passage 35 for allowing the timing chain 34 to travel.

  A left cover 36 is fastened to the left case half 21L so as to cover the left end portion of the crankshaft 24, and a rotor 37 fixed to the left end portion of the crankshaft 24 and the left cover so as to cover the rotor 37. A generator 39 is constituted by a stator 38 fixed to 36.

  The power transmission device T includes a V-belt transmission 41 that is a continuously variable transmission, and a gear reducer 42 that decelerates the output of the V-belt transmission 41 in three stages. A transmission case 44 that forms a transmission chamber 43 that accommodates 41 includes an inner case 45 that is fastened to the right case half 21R, and an outer case 46 that is coupled to the inner case 45 from the right side.

  A gap is defined between the transmission case 44 and the crankcase 21, and a drive gear 47 disposed in the gap is fixed to the right end portion of the crankshaft 24, and has an axis parallel to the crankshaft 24. Then, a driven gear 48 that meshes with the drive gear 47 is fixed to a primary shaft 49 that rotatably passes through the inner case 45, and an axially intermediate portion of the primary shaft 49 rotates through the ball bearing 51 to the inner case 45. Both end portions of the primary shaft 49 are rotatably supported by the right case half 21R and the outer case 46 via roller bearings 52 and ball bearings 53. A secondary shaft 54 having an axis parallel to the primary shaft 49 passes through the inner case 45 and the right case half 21R in a rotatable manner, and an intermediate portion in the axial direction of the secondary shaft 54 is a ball serving as a first bearing in the right case 21R. Both ends of the secondary shaft 54 are rotatably supported on the left case half 21L via a ball bearing 56 as a second bearing and are externally connected via a ball bearing 57. The case 46 is rotatably supported. In addition, an endless seal member 58 is interposed between the primary shaft 49 and the inner case 45, and an endless seal member 59 is interposed between the secondary shaft 54 and the inner case 45.

  The V-belt type transmission 41 is secondary in the transmission chamber 43 via a centrifugal clutch 64 that can connect and disconnect between the drive pulley 61 attached to the primary shaft 49 and the secondary shaft 54 in the transmission chamber 43. A driven pulley 62 mounted on the shaft 54 and a drive pulley 61 and an endless V-belt 63 wound around the driven pulley 62 are provided.

  The drive pulley 61 is fixed to a portion of the primary shaft 49 near the inner case 45, and is attached to the primary shaft 49 so as to be axially slidable on the outer side in the axial direction from the fixed pulley half 65. The V-belt 63 is wound around a V-shaped annular groove 67 formed between the two pulley halves 65 and 66. A ramp plate 68 is fixed to the primary shaft 49 on the back side of the movable pulley half 66, and a plurality of weight rollers 69 are accommodated between the movable pulley half 66 and the ramp plate 68 in a floating state. Thus, when the rotation speed of the primary shaft 49 increases in accordance with the increase in the rotation speed of the crankshaft 24, the weight rollers 69, which receive centrifugal force, move outward in the radial direction of the primary shaft 49 to move the movable pulley half 66. Close to the fixed pulley half 65. As a result, the contact radius of the V-belt 63 to both pulley halves 65 and 66 increases.

  The driven pulley 62 is an outer cylinder 71 that allows relative rotation and coaxially surrounds the secondary shaft 54, and allows the inner cylinder 71 to be slidably fitted so as to allow relative rotation around the axis and relative movement in the axial direction. A cylinder 72, a fixed pulley half 73 fixed to the inner cylinder 71, a movable pulley half 74 fixed to the outer cylinder 72 opposite to the fixed pulley half 73, the movable pulley half 74 and the fixed A torque cam mechanism 75 provided between the inner cylinder 71 and the outer cylinder 72 so as to apply an axial component force between the pulley halves 73 and 74 in accordance with the relative rotational phase difference between the pulley halves 73; A coil spring 76 that elastically biases the pulley half 74 toward the fixed pulley half 73, and a V-shaped annular groove 77 formed between the fixed pulley half 73 and the movable pulley half 74. V belt 3 is wound.

The centrifugal clutch 64 is disposed between the driven pulley 62 and the inner case 45, and has a drive plate 78 fixed to the outer cylinder 72 and a crankcase 21 side so as to cover the drive plate 78. A clutch housing 79 formed in a tapered bowl shape and fixed to the secondary shaft 54, and a plurality of clutch weights 80 attached to the drive plate 78 so as to be capable of frictional contact with the inner periphery of the clutch housing 79 Is provided.

  Thus, the distance between the fixed pulley half 73 and the movable pulley half 74 in the driven pulley 62 is such that the axial force generated by the torque cam mechanism 75, the axial elastic force generated by the coil spring 76, and the fixed pulley half. By determining the balance with the force from the V-belt 63 acting in the direction to leave the space between the body 73 and the movable pulley half 74, the movable pulley half 66 is brought close to the fixed pulley half 65 in the drive pulley 61. When the winding radius of the V belt 63 around the drive pulley 61 increases, the winding radius of the V belt 63 around the driven pulley 62 decreases.

  A counter shaft 83 having an axis parallel to the secondary shaft 54 is disposed behind the secondary shaft 54. Both ends of the counter shaft 83 are connected to the right and left case halves 21R and 21L of the crankcase 21. Chain transmission means for transmitting power to the rear wheel WR to the left end portion of the counter shaft 83 which is rotatably supported via the ball bearings 84 and 85 which are the third and fourth bearings and protrudes from the left case half body 21L. A drive sprocket 86 constituting a part of 13 is fixed.

  Moreover, the counter shaft 83 is disposed in the centrifugal clutch 64 and the driven pulley 62 mounted on the secondary shaft 54 on a projection view onto a plane orthogonal to the axis of the secondary shaft 54.

  The gear reducer 42 is provided between the secondary shaft 54 and the counter shaft 83 in the crankcase 21 and meshes with a primary reduction drive gear 87 fixed to the secondary shaft 54 and a primary reduction drive gear 87. Thus, the primary reduction driven gear 88 rotatably supported on the counter shaft 83, the secondary reduction drive gear 89 formed integrally with the primary reduction driven gear 88, and the secondary shaft 54 are rotatably supported. A secondary reduction driven gear 90 meshed with the secondary reduction drive gear 89, a tertiary reduction drive gear 91 formed integrally with the secondary reduction driven gear 90, and the tertiary reduction drive gear 91 fixed to the counter shaft 83. A primary reduction driven gear 88 and a secondary reduction drive gear 89 that are integral with each other and a counter shaft 83 are cylindrical. 1 metal bearing 93 is interposed, the second metal bearing 94 is a cylindrical is interposed between the secondary reduction driven gear 90 and the tertiary reduction drive gear 91 and the secondary shaft 54 are integral.

  By the way, the primary reduction drive gear 87, the secondary reduction driven gear 90, and the tertiary reduction drive gear 91 are mounted on the secondary shaft 54 between the ball bearings 55, 56, and the secondary shaft 54 is connected to the primary reduction drive gear. While the drive gear 87, the secondary reduction driven gear 90 and the tertiary reduction drive gear 91 are rotatably supported on the crankcase 21 via ball bearings 55 and 56 on both axial sides, the primary reduction driven gear 88, The secondary reduction drive gear 89 and the tertiary reduction driven gear 92 are mounted on the counter shaft 83 between the ball bearings 84 and 85, and the primary reduction driven gear 88, the secondary reduction drive gear 89, and the tertiary reduction drive. On one side in the axial direction of the driven vehicle 92, the counter shaft 83 is substantially the same as the ball bearing 55 in the direction along the axis of the counter shaft 83. The other side in the axial direction of the primary reduction driven gear 88, the secondary reduction drive gear 89, and the tertiary reduction driven gear 92 is rotatably supported by the right case half 21R of the crankcase 21 via a ball bearing 84 disposed in the position. Thus, the counter shaft 83 is rotatably supported on the left case half 21L of the crankcase 21 via a ball bearing 85 that is disposed at substantially the same position as the ball bearing 56 in the direction along the axis of the counter shaft 83. .

  Moreover, the reduction ratios of the primary reduction drive gear 87 and the primary reduction driven gear 88, the secondary reduction drive gear 89 and the secondary reduction driven gear 90, and the tertiary reduction drive gear 91 and the tertiary reduction driven gear 92 are all set to be the same. The shapes of the integrated primary reduction driven gear 88 and the secondary reduction drive gear 89 and the integrated shapes of the secondary reduction driven gear 90 and the tertiary reduction drive gear 91 are set to be the same.

  Further, the first metal bearing 93 interposed between the integral primary reduction driven gear 88 and the secondary reduction drive gear 89 and the counter shaft 83 has an inner end in an oil passage 105 provided coaxially with the counter shaft 83. And a lubricating oil hole 107 having an outer end opened to the outer periphery is provided so as to extend in a radial direction at a position corresponding to an intermediate portion between the primary reduction driven gear 88 and the secondary reduction driving gear 89. A second metal bearing 94 interposed between the secondary reduction driven gear 90 and the tertiary reduction drive gear 91 and the secondary shaft 54 communicates the inner end with an oil passage 106 provided coaxially with the secondary shaft 54. In addition, a lubricating oil hole 108 whose outer end opens to the outer periphery extends in a radial direction at a position corresponding to an intermediate portion between the secondary reduction driven gear 90 and the tertiary reduction drive gear 91. Eclipsed. Thus, oil is supplied from an oil supply passage (not shown) provided in the crankcase 21 to the oil passage 105 provided in the counter shaft 83 and the oil passage 106 provided in the secondary shaft 54.

A kick shaft 95 having an axis parallel to the crankshaft 24 is rotatably supported across the cases 21 and 45 on the rear portion of the inner case 45 and the crankcase 21 in the transmission case 44. The outer end portion to which the kick pedal 96 is attached is disposed inward of the outer end surface of the outer case 46 of the transmission case 44 in the axial direction of the crankshaft 24. A kick drive gear 98 is rotatably supported on the kick shaft 95 on the inner side of the inner case 45, and the power of the kick shaft 95 according to the depression operation of the kick pedal 96 is passed through the kick starter 97. Is transmitted to the kick drive gear 98. Further, the rotational power of the kick drive gear 98 is rotatably supported by the right end portion of the counter shaft 83 projecting from the right case half 21R of the crankcase 21 into the gap between the transmission case 44 and the crankcase 21, thereby kick driving. A first idle gear 99 meshed with the gear 98, a second idle gear disposed in the gap and rotatably supported on the secondary shaft 54 between the crankcase 21 and the transmission case 44 and meshed with the first idle gear 99 The third idle gear 101 is integrally formed on the side of the gear case 100 and the second idle gear 100 on the transmission case 44 side and is disposed in the gap and meshes with the drive gear 47 at the right end of the crankshaft 24. Is transmitted to the crankshaft 24 via In addition, a portion of the inner case 45 facing the clutch housing 79 is formed in a bowl shape along the clutch housing 79, and a portion of the third idle gear 101 facing the clutch housing 79 across the inner case 45 is so as to avoid the right end portion of the counter shaft 83 facing the air gap, it is formed on the clutch housing 79 along cormorants bowl shape.

  Next, the operation of this embodiment will be described. The gear reducer 42 which is provided between the secondary shaft 54 and the counter shaft 83 having mutually parallel axes and constitutes a part of the power unit P is fixed to the secondary shaft 54. A primary reduction drive gear 87, a primary reduction driven gear 88 rotatably supported on the counter shaft 83 so as to mesh with the primary reduction drive gear 87, and a secondary reduction formed integrally with the primary reduction driven gear 88. A drive gear 89, a secondary reduction driven gear 90 that is rotatably supported by the secondary shaft 54 and meshes with the secondary reduction drive gear 89, and a tertiary reduction drive gear 91 formed integrally with the secondary reduction driven gear 90. And a tertiary reduction driven gear 92 fixed to the counter shaft 83 and meshing with the tertiary reduction drive gear 91, the power input to the secondary shaft 54 is As indicated by the chain arrows in FIG. 3, the primary reduction drive gear 87, the secondary reduction drive gear 89, the secondary reduction driven gear 90, the tertiary reduction drive gear 91, and the tertiary reduction gears are attached to the secondary shaft 54. Through the S-shaped transmission path so that the reduction driven gear 92 sequentially passes, the speed is reduced in three stages and transmitted to the counter shaft 83, and the distance between the secondary shaft 54 and the counter shaft 83 is shortened. In addition, it is possible to obtain a large reduction ratio while making it possible to set the outer diameters of the gears 87 to 92 constituting the gear reducer 42 to be small, and in the direction perpendicular to the axes of the secondary shaft 54 and the counter shaft 83. The length of the gear reducer 42 can be shortened, and an increase in cost and weight can be avoided. Moreover, the secondary shaft 54 and the counter shaft 83 are rotatably arranged in parallel with each other, and the structure of the gear reducer 42 is not complicated.

  Further, the secondary shaft 54 and the counter shaft 83 constitute a part of the power unit P mounted on the motorcycle and are arranged at intervals in the front-rear direction of the motorcycle, and are on a plane orthogonal to the axis of the secondary shaft 54. Since the counter shaft 83 is disposed in the centrifugal clutch 64 and the driven pulley 62 attached to the secondary shaft 54, the power unit P can be made compact while easily securing the space for disposing the gear reducer 42. Can be achieved.

  Since the reduction ratios of the primary reduction drive gear 87 and the primary reduction driven gear 88, the secondary reduction drive gear 89 and the secondary reduction driven gear 90, and the tertiary reduction drive gear 91 and the tertiary reduction driven gear 92 are all set to be the same. The primary reduction driven gear 88 and the secondary reduction drive gear 89 that are integrally formed, and the secondary reduction driven gear 90 and the tertiary reduction drive gear 91 that are integrally formed can be formed in the same shape. The score can be reduced.

  The secondary shaft 54 is rotatably supported on the crankcase 21 via ball bearings 55 and 56 on both axial sides of the primary reduction drive gear 87, the secondary reduction driven gear 90, and the tertiary reduction drive gear 91. On one side in the axial direction of the reduction driven gear 88, the secondary reduction drive gear 89, and the tertiary reduction driven gear 92, the counter shaft 83 is disposed at substantially the same position as the ball bearing 55 in the direction along the axis of the counter shaft 83. The countershaft is rotatably supported on the right case half 21R of the crankcase 21 via a ball bearing 84, and on the other side in the axial direction of the primary reduction driven gear 88, the secondary reduction driven gear 89 and the tertiary reduction driven gear 92. The ball bearings 85 are disposed at substantially the same positions as the ball bearings 56 in the direction along the axis 83. Rotatably on the left case half 21L of Kukesu 21 are supported.

  According to such a rotation support structure of the secondary shaft 54 and the counter shaft 83 to the crankcase 21, the processing applied to the crankcase 21 for rotatably supporting the secondary shaft 54 and the counter shaft 83 is simplified. In addition, the surface pressure of the support portion by the crankcase 21 of the secondary shaft 54 and the counter shaft 83 can be reduced.

  Further, an integrally formed primary reduction driven gear 88 and a secondary reduction drive gear 89 are rotatably supported on the counter shaft 83 via a cylindrical first metal bearing 93 and are integrally formed. A driven gear 90 and a tertiary reduction drive gear 91 are rotatably supported on the secondary shaft 54 via a cylindrical second metal bearing 94. The first and second metal bearings 93, 94 are connected to the counter shaft 83 and Lubricating oil holes 107, 108 that communicate with the inner ends of oil passages 105, 106 that are provided coaxially with the secondary shaft 54 and that open to the outer periphery of the outer ends are provided extending in the radial direction, so that the primary reduction driven gear 88 is provided. And the secondary reduction drive gear 89, and the secondary reduction driven gear 90 and the tertiary reduction drive gear 91 are supported on the counter shaft 83 and the secondary shaft 54. The lubrication structure to the part is simplified, and from between the first and second metal bearings 93 and 94, the primary reduction driven gear 88 and the secondary reduction drive gear 89, the secondary reduction driven gear 90 and the tertiary reduction drive gear 91. The oil that has flowed out can be used to lubricate the meshing portions of the gears 87 to 92.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

1 is a side view of a motorcycle. It is a side view of a power unit. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2.

21 ... Crankcase 24 ... Crankshaft 41 ... Transmission (V-belt type transmission)
42 ... gear reducer 44 ... transmission case 47 ... crankshaft drive gear 54 ... drive shaft secondary shaft 55 ... first bearing ball bearing 56 ... second Ball bearing 62 as a bearing ... Driven pulley 64 ... Centrifugal clutch
79 ... Clutch housing 83 ... Counter shaft 84 as driven shaft ... Ball bearing 85 as third bearing ... Ball bearing 87 as fourth bearing ... Primary reduction drive gear 88 ... Primary reduction driven gear 89 ... Secondary reduction drive gear 90 ... Secondary reduction driven gear 91 ... Third reduction drive gear 92 ... Third reduction driven gear 93 ... First metal bearing 94 ... Second metal bearing 95 ... kick shaft 96 ... kick pedal 98 ... kick drive gear 99 ... first idle gear 100 ... second idle gear 101 ... third idle gear 105, 106 ... Oil passages 107, 108 ... Lubricating oil hole E ... Engine T ... Power transmission device WR ... Wheel (rear wheel)

Claims (5)

The crankshaft (24) has an engine (E) and a power transmission device (T) extending in the vehicle width direction and is mounted on the vehicle, and the power transmission device (T) is a crankshaft of the engine (E). A V-belt continuously variable transmission (41) for shifting the output of (24) and a gear reducer (42) for reducing the output of the V-belt continuously variable transmission (41). (42), connected to said axis and extending parallel to the engine (E) the crank case (21) is rotatably supported by the V-belt type continuously variable transmission of the output side (41) of the crank shaft (24) A driven shaft (54) that extends in parallel with the drive shaft (54) in the longitudinal direction of the vehicle and is rotatably supported by the crankcase (21) and interlocked with the wheel (WR). 83) in the vehicle power unit provided between ,
The gear reducer (42) is supported by the primary reduction drive gear (87) fixed to the drive shaft (54) and the driven shaft (83) so as to be rotatable relative to the primary reduction drive gear (87). ), A secondary reduction drive gear (89) formed integrally with the primary reduction driven gear (88), and the drive shaft (54) so as to be rotatable relative to the primary reduction driven gear (88). A secondary reduction driven gear (90) meshing with the secondary reduction drive gear (89), a tertiary reduction drive gear (91) formed integrally with the secondary reduction driven gear (90), and the driven shaft A tertiary reduction driven gear (92) fixed to (83) and meshing with the tertiary reduction drive gear (91);
A transmission case (44) accommodating the V-belt type continuously variable transmission (41) and the crankcase (21) are coupled to each other, and the driven shaft ( one end and the voids to face the part of the drive shaft (54) of 83) is defined,
A kick shaft (95) having an axis extending in parallel with the axis of the crank shaft (24) is rotatably supported across the cases (21, 44), and the kick pedal of the kick shaft (95) is supported. The outer end portion to which (96) is attached is disposed on the inner side of the outer end surface of the transmission case (44) in the axial direction of the crankshaft (24),
A kick drive gear (98) rotatably supported by the kick shaft (95), and a gear disposed in the gap, meshing with the kick drive gear (98), and rotatable at the one end of the driven shaft (83) The first idle gear (99) supported by the first idle gear (99) and the second idle gear (100) disposed in the gap, meshed with the first idle gear (99), and rotatably supported by the drive shaft (54). ), A third idle gear (101) integrally formed on the side of the transmission case (44) side of the second idle gear (100) and disposed in the gap, and disposed in the gap. The kick shaft (95) and the crank shaft (24) are connected via a drive gear (47) meshed with the third idle gear (101) and fixed to the end of the crank shaft (24). Linked, linked ,
Centrifugal clutch capable of connecting / disconnecting a drive pulley (62) and a driven pulley (62) mounted on the drive shaft (54), constituting a part of the V-belt type continuously variable transmission (41) (64) is provided on the drive shaft (54) adjacent to the crankcase (21) side of the driven pulley (62), and on a projection view on a plane orthogonal to the axis of the drive shaft (54). The driven shaft (83) is disposed in the centrifugal clutch (64),
The centrifugal clutch (64) includes a clutch housing (79) formed in a tapered bowl shape on the crankcase (21) side and fixed to the drive shaft (54).
A portion of the transmission case (44) facing the clutch housing (79) is formed in a bowl shape along the clutch housing (79).
Further, a portion of the third idle gear (101) facing the clutch housing (79) across the transmission case (44) avoids the one end portion facing the gap of the driven shaft (83). a manner, a power unit for a vehicle, characterized in Rukoto formed like a bowl along the clutch housing (79). In projection of the plane perpendicular to the axis of the front SL drive shaft (54), for a vehicle according to claim 1, wherein said driven shaft (83) that is disposed in front Kido Ribunpuri (62) in Power unit. Primary reduction drive gear (87) and primary reduction driven gear (88), secondary reduction drive gear (89) and secondary reduction driven gear (90), and tertiary reduction drive gear (91) and tertiary reduction driven gear (92) power unit according to claim 1 or 2 reduction ratio, characterized in that all are set to the same by. The drive shaft (54) is attached to the crankcase (21) at the first and second bearings on both axial sides of the primary reduction drive gear (87), the secondary reduction driven gear (90) and the tertiary reduction drive gear (91). (55, 56) rotatably supported by the driven shaft (83) on one side in the axial direction of the primary reduction driven gear (88), the secondary reduction drive gear (89) and the tertiary reduction driven gear (92). ) Is rotatably supported on the crankcase (21) via a third bearing (84) disposed at substantially the same position as the first bearing (55) in a direction along the axis of the driven shaft (83). The driven shaft (83) is along the axis of the driven shaft (83) on the other side in the axial direction of the primary reduction driven gear (88), the secondary reduction drive gear (89) and the tertiary reduction driven gear (92). At approximately the same position as the second bearing (56). The fourth power unit according to any one of claims 1 to 3, via a bearing (85), characterized in that it is rotatably supported on the crankcase (21) that. The integrally formed primary reduction driven gear (88) and the secondary reduction drive gear (89) are rotatably supported on the driven shaft (83) via a cylindrical first metal bearing (93). The secondary reduction driven gear (90) and the tertiary reduction drive gear (91), which are integrally formed, are rotatably supported on the drive shaft (54) via a cylindrical second metal bearing (94). The inner ends of the first and second metal bearings (93, 94) communicate with the oil passages (105, 106) provided coaxially with the driven shaft (83) and the drive shaft (54), and The vehicular power unit according to any one of claims 1 to 4 , wherein lubricating oil holes (107, 108) whose ends are opened to the outer periphery extend in the radial direction.

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