JP2002046493A - Power unit mounted on vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent lowering down of the lowest ground height of a vehicle while concentration of mass and compactness are attained, in a power unit mounted on the vehicle. SOLUTION: This power unit P mounted on a vehicle comprises an internal combustion engine E, a transmission 70 having a speed change part 70a and an output part 70b, a final reduction gear R2 transmitting power of the output part 70b through an intermediate reduction gear R1, and a transmitting case C storing the transmission 70, power from the final reduction gear R2 is transmitted to a rear axle 13 as a drive shaft. The intermediate/final reduction gears R1, R2 are stored in the transmitting case C, the speed change part 70a and the output part 70b are respectively arranged in a side of the internal combustion engine E and in a side opposite to the internal combustion engine E relating to the rear axle 13, the transmission 70 is arranged upward the intermediate reduction gear R1 arranged upward relating to the final reduction gear R2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power unit mounted on a vehicle and transmitting power of an internal combustion engine to a drive shaft via a clutch, a transmission, and a reduction gear, and more particularly, to an internal combustion engine constituting the power unit. The present invention relates to an arrangement structure of an engine, a clutch, a transmission, and a reduction gear.

[0002]

2. Description of the Related Art Conventionally, this type of apparatus has been disclosed in Japanese Utility Model Application Laid-open No.
A driving device for a four-wheeled motor vehicle disclosed in Japanese Patent No. 28116 is known. The drive device includes an engine having a crankshaft vertically disposed with respect to a vehicle body, a first input shaft interlocked with the crankshaft via a reduction gear and a clutch, a speed change mechanism, and a second input to the speed change mechanism. A transmission having a shaft and an output shaft from the speed change mechanism, and a pair of gears for interlocking the first input shaft and the second input shaft.
The second input shaft, the speed change mechanism, and the output shaft that constitute the transmission are disposed in the gear case, and the output shaft and the rear wheel drive shaft are linked via a bevel gear that constitutes the final reduction gear.

[0003]

By the way, in the prior art, a speed change mechanism connected to a second input shaft extending rearward from an engine disposed in front of the rear wheel drive shaft is provided behind the rear wheel drive shaft. Since it is arranged, the mass of the drive unit including the engine in the front-rear direction is not concentrated, and there is room for improvement in terms of maneuverability, the gear case becomes large, and the drive unit composed of the engine and the transmission However, the size of the vehicle body has been restricted, and the degree of freedom of arrangement of members arranged around the vehicle has been restricted, and the size of the vehicle body in the front-rear direction has been increased. Further, since the output shaft is coaxial with the input shaft of the final reduction gear, a relatively large-diameter transmission mechanism is located near the rear wheel drive shaft in the vertical direction, so that the minimum ground clearance of the vehicle is reduced. was there.

[0004] The present invention has been made in view of such circumstances, and in a power unit mounted on a vehicle, mass concentration and compactness are achieved, and the minimum ground clearance of the vehicle is reduced. The purpose is to prevent it.

[0005]

The invention according to claim 1 of the present application is directed to an internal combustion engine, a transmission section to which the power of a crankshaft of the internal combustion engine is transmitted, and the power shifted by the transmission section. A transmission having an output section for outputting the power, a final reduction gear in which the power of the output section is transmitted via an intermediate reduction gear, and a transmission case for housing the transmission. In a power unit mounted on a vehicle that is transmitted to a drive shaft, the transmission case houses the intermediate reduction device and the final reduction device,
With respect to the drive shaft, the transmission section is disposed on the internal combustion engine side, and the output section is disposed on the anti-internal combustion engine side, and the transmission is shifted above the intermediate reduction gear disposed above the final reduction gear. Power unit mounted on the vehicle in which the aircraft is located.

According to the first aspect of the present invention, the transmission portion of the transmission is disposed on the side of the internal combustion engine with respect to the drive shaft. Since it is located relatively close to the internal combustion engine, the mass of the power unit mounted on the vehicle is concentrated. Further, since the intermediate reduction gear and the final reduction gear are in a vertical positional relationship, the two reduction gears are arranged in parallel in the front-rear direction, and a transmission unit is provided on the internal combustion engine side with respect to the drive shaft. Since the output section is disposed on the side, the distance between the output section and the drive shaft can be shortened, so that the transmission case accommodating the transmission, the intermediate reduction gear and the final reduction gear can be made compact. Can be. Further, in the power unit, since the transmission is located further above the intermediate reduction gear above the final reduction gear, it is located relatively far from the drive shaft in the vertical direction. The minimum ground clearance is prevented from lowering.

As a result, in the power unit, the mass is concentrated, and the maneuverability of the vehicle is improved. Moreover,
Since the transmission case can be made compact, the power unit becomes compact, and the degree of freedom of arrangement of members arranged around the power unit increases. Further, it is possible to prevent the minimum ground clearance of the vehicle from being reduced due to the arrangement of the transmission of the power unit.

According to a second aspect of the present invention, in the power unit mounted on the vehicle according to the first aspect, the transmission includes a clutch having a clutch shaft disposed above the crankshaft. A transmission shaft that is drivingly connected to the transmission unit to transmit power to the transmission unit, the clutch shaft is coaxial with the transmission shaft, and the clutch is disposed in parallel with the crankshaft in the front-rear direction. .

According to the second aspect of the present invention, in addition to the operation of the first aspect, the crankshaft is more coaxial with the drive shaft than the clutch and the transmission because the clutch shaft and the transmission shaft are coaxial. Since it occupies a near position, the center of gravity of the vehicle can be reduced. Further, since the clutch shaft and the transmission shaft are coaxial and the clutch having the clutch shaft is arranged in parallel with the crankshaft in the front-rear direction, the transmission can be arranged closer to the internal combustion engine in the front-rear direction. Also in this regard, the power unit can concentrate the mass in the front-rear direction and can be compact in the front-rear direction.

As a result, among the effects of the first aspect of the present invention, the concentration of the mass of the power unit and the compactness thereof can be further promoted, the center of gravity of the vehicle can be reduced, and the running stability is improved.

According to a third aspect of the present invention, in the power unit mounted on the vehicle according to the second aspect, the crankshaft is disposed so as to be oriented in the front-rear direction, and one side in the left-right direction with respect to the crankshaft. The cylinder of the internal combustion engine having a substantially horizontal center axis is arranged, and the clutch, the transmission and the transmission, each having a rotation axis parallel to the rotation axis of the crankshaft on the other side in the left-right direction. The intermediate reduction gear is disposed.

According to the third aspect of the invention, in addition to the operation of the second aspect of the invention, the crankshaft is located on a side opposite to the side on which the cylinder occupying a large space is disposed. Since the clutch, the transmission and the intermediate reduction gear, each having a rotation axis parallel to the rotation axis of the crankshaft, are arranged, the components of the power unit can be compactly arranged around the rotation axis of the crankshaft. In a space formed directly behind the cylinder on the side where the cylinder is disposed, an accessory (for example, an air cleaner) of the internal combustion engine and a component attached to the vehicle body can be disposed. Moreover, since the center axis of the cylinder is substantially horizontal, the center of gravity of the internal combustion engine can be lowered, and the center of gravity of the vehicle can be lowered.

As a result, of the effects of the invention described in claim 2, the center of gravity of the vehicle can be further reduced.
The components of the power unit are compactly arranged around the rotation axis of the crankshaft, and the power unit can be made compact around the rotation axis of the crankshaft,
Moreover, parts can be arranged by utilizing the space formed directly behind the cylinder, and the body can be made compact.

In this specification, "upper",
“Bottom”, “Front”, “Rear”, “Left” and “Right” mean “Top”, “Bottom”, “Front”, “Rear”, “Left” and “Right”, respectively. .

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG. FIG. 1 is a left side view of a main part showing the positional relationship between a body frame F and a power unit P of a scooter-type three-wheeled motor vehicle V on which the power unit of the present invention is mounted. A three-wheeled motor vehicle V having one front wheel Wf, which is a driven wheel, and a pair of left and right rear wheels Wr, which are driving wheels, has a front frame 1 having a rear portion branched right and left, and bolts at the rear of the front frame 1. And a body frame F having a sub-frame 3 and a main frame composed of a pair of right and left rear frames 2 joined together by a frame.

A front portion of the front frame 1 has a front wheel Wf.
Steering mechanism 4 for steering the front frame 1
And a front suspension mechanism 6 having a swing arm 5 that is pivotably supported around a horizontal axis and supports a front wheel Wf. Further, at the rear of the front frame 1, a cylindrical portion, a shaft inserted into the cylindrical portion, and a rubber elastic body provided in a radial gap between the cylindrical portion and the shaft. A power unit P for driving left and right rear wheels Wr is supported by a pair of left and right sub-frames 3 which are attached via bolts to the cylindrical part of the Neidhart mechanism 7 having a plate 8 attached thereto. Is done. Further, a seat 9 is disposed above a rear portion of the front frame 1, and a storage box 10 having an opening portion opened and closed by the seat 9 and storing articles such as a helmet is provided below the seat 9.

A front part of a power unit P having a water-cooled internal combustion engine E and a transmission M is provided with a hanger hole of a bracket 11 attached to each of the two subframes 3 and a pair of right and left bushes provided on the internal combustion engine E. 12 (the left bush 12 is shown in FIG. 1), and is pivotally supported on both subframes 3 by a pair of hanger bolts respectively inserted. A lower end of the rear portion of the power unit P is pivotally supported by a bush (not shown) provided on the right side of a transmission case C in which the transmission device M is accommodated, in front of the rear axle 13.
The upper ends are supported by the two sub-frames 3 via a shock absorber 14 that is pivotally supported between the rear ends of the rear portions of the sub-frames 3 whose rear portions are bent and occupy a position near the center in the left-right direction of the vehicle body. Accordingly, the power unit P is swingable around the left-right axis of the left and right bushes 12 with respect to the main frame, and is swingable around the front-rear axis of the Neidhart mechanism 7.

Next, a sectional view taken along the central axis L2 of the cylinder 22 is viewed from the back and is a view for explaining the positional relationship between the rotation axes of the respective axes.
3 which is a cross-sectional view taken along the line II, and substantially IV-IV in FIG.
Referring to FIG. 4 which is a sectional view taken along a line, an internal combustion engine E constituting power unit P and the power of internal combustion engine E are transmitted to rear wheels Wr.
Will be further described.

The transmission M includes a centrifugal clutch 60, a cone-type continuously variable transmission 70, an intermediate reduction gear R1 and a final reduction gear R2, of which the clutch 60 is housed in the crankcase 21 of the internal combustion engine E. Then, the continuously variable transmission 70, the intermediate reduction gear R1 and the final reduction gear R2 are housed in the transmission case C.

Referring to FIGS. 2 and 4, the internal combustion engine E
Is a single-cylinder four-cycle internal combustion engine having a crankshaft 20
Is arranged vertically with its rotation axis L1 oriented in the front-rear direction of the vehicle body, and is disposed substantially at the center of the vehicle body in the left-right direction. A center axis L2 that is substantially horizontal to the rotation axis L1 of the crankshaft 20, that is, extends rightward or diagonally upward to the right within a range of 0 ° to 20 ° with respect to the horizontal direction. Is disposed on the right side of the crankshaft 20, while the clutch 60, the continuously variable transmission 70, the intermediate reduction gear R1 and the final reduction gear R2
Is disposed on the left side of the crankshaft 20. Further, the clutch shaft 61 of the clutch 60 and the transmission shaft 71 of the continuously variable transmission 70
Are coaxial, and their rotation axes L3 and L4 are parallel to the rotation axis L1, and are disposed obliquely above the rotation axis L1 at an angle larger than the center axis L2 of the cylinder 22 from the horizontal direction. Is done.

The crankcase 21 of the internal combustion engine E has a right crankcase 21R integrally formed with the cylinder 22 by casting using a plane including the rotation axis L1 and orthogonal to the center axis L2 of the cylinder 22 as a dividing plane, and a clutch 60. And is divided into a left crankcase 21L that accommodates Then, a cylinder head 23 and a cylinder head cover 24 are sequentially assembled to the cylinder 22. A reciprocating piston 25 which is slidably fitted to the cylinder 22 is connected to the crankshaft 20 via a connecting rod 26.
20 is driven to rotate. The cylinder head 23 is provided with an intake passage 28, an exhaust passage 29, and a supercharging passage 30 that open to the combustion chamber 27, and further includes a mixture of fuel and intake air injected from the fuel injection valve into the intake passage 28. A spark plug 31 for igniting is mounted. Further, above the cylinder 22,
A double-acting piston-type supercharger 32 having a reciprocating supercharging piston 32a is provided. The supercharging piston 32a is rotated by a transmission belt stretched between a supercharging crankshaft that is drivingly connected to the supercharging piston 32a and a camshaft 43 described later. The reciprocating drive is performed by being rotationally driven at the speed.

Referring to FIG. 3, the crankshaft 20 is disposed at a predetermined interval in the front-rear direction, and is connected to the crankcase 21 and the cylinder 22 by a plurality of bolts fastened in the direction of the rotation axis L1. Are rotatably supported by a pair of crankshaft holders 33, 34 via ball bearings 35, 36 as a pair of main bearings.

Crankshaft 20 extending forward from ball bearing 35
An AC generator 37 is provided at the front end of the AC generator 37, and the rotor of the AC generator 37 fixed integrally to the crankshaft 20 has a cooling device for blowing cooling air to a radiator 38 disposed in front of the rotor. A fan 39 is integrally rotatably connected.

A trochoid type oil pump 40 is provided at the rear of the crankshaft 20, and a hollow pump drive shaft 40a made of a tubular material and fixed to the rear end of the crankshaft 20 extending rearward from the ball bearing 36. Accordingly, the rotor is rotationally driven inside the pump casing fixed to the crankcase 21. Then, the oil sucked from the oil reservoir at the bottom of the crankcase 21 and discharged from the oil pump 40,
An oil filter attached to the left side of the transmission case C through an oil passage formed by the hollow portion of the pump drive shaft 40a, and through an oil passage provided in the crankcase 21, the cylinder 22, and the cylinder head 23. The oil is supplied to various lubricating points such as the internal combustion engine E, the clutch 60 and the continuously variable transmission 70 through the 41 (see FIG. 1).

Referring to FIG. 2, a timing gear 42 connected to the rear end of the crankshaft 20 includes two crankshaft holders.
The camshaft 43 meshes with a cam gear 44 coupled to a camshaft 43 rotatably supported by 33 and 34 so that the camshaft 43 is １ ／ of the crankshaft 20.
Is driven at a reduction ratio of. The intake, exhaust and supercharging cams provided on the camshaft 43 are
The intake, exhaust and supercharging cam followers constituting a cam follower group 46 swingably supported by support shafts 45 supported by 33 and 34 are respectively swung. The movements of the cam followers move through the intake, exhaust, and supercharged pull rods that constitute the pull rod group 47, and the intake air that constitutes the rocker arm group 49 that is swingably supported by the rocker arm shaft 48 provided on the cylinder head 23. The intake valve 50, the exhaust valve 51, and the supercharging valve 52, which are in contact with the rocker arms, respectively, oscillate the exhaust and the supercharging rocker arms so that the combustion of the intake passage 28, the exhaust passage 29, and the supercharging passage 30 is performed at a predetermined timing. The opening on the side of the chamber 27 is opened and closed.

A drive gear 53 provided on the outer periphery of the rear crank web of the crankshaft 20 is rotatably mounted on the clutch shaft 61 and meshes with a driven gear 62 rotated at the same rotation speed as the drive gear 53. The power of the crankshaft 20 is continuously variable by being spline-coupled to a clutch shaft 61 rotatably supported on both crankshaft holders 33 and 34 via a pair of ball bearings 63 and 64 respectively mounted on the crankshaft holders 33 and 34. Transmission shaft 71 of machine 70
Is transmitted to Thus, the clutch 60 is disposed between the two crankshaft holders 33 and 34, and
The clutch shaft 60 and the clutch shaft 61 are arranged in parallel with the crankshaft 20 located diagonally right below them in the front-rear direction.

The clutch 60 as a starting clutch includes a bowl-shaped clutch outer 60a that is integrally rotatably connected to the clutch shaft 61, and a driven gear inside the clutch outer 60a.
And a drive plate 60b that is drivingly connected to 62 and rotatably fitted to the clutch shaft 61. And the driven gear 6
2 rotates at a rotation speed higher than a predetermined rotation speed of the internal combustion engine E, a plurality of clutch shoes 60c swingably supported by the drive plate 60b
Oscillating radially outward due to centrifugal force against the elastic force of 0d,
The friction member provided on the outer peripheral surface of each clutch shoe 60c abuts on the inner peripheral surface of the clutch outer 60a, the clutch 60 is connected, and the rotation of the driven gear 62 is transmitted to the clutch shaft 61.

Transmission shaft to which power of clutch shaft 61 is transmitted
Reference numeral 71 denotes a spline connection portion between a front end portion of the crankshaft holders 33 and 34 and the clutch shaft 61, a ball bearing 64 together with a rear end portion of the clutch shaft 61 on the outer peripheral side, and a rear end portion thereof. The transmission case C is rotatably supported via a ball bearing 72. The continuously variable transmission 70 includes a transmission unit 70a that changes the rotation speed of the transmission shaft 71, and an output unit 70b that outputs power at the rotation speed changed by the transmission unit 70a. Here, the transmission 70a is provided with a rear axle 13 as a drive shaft in the front-rear direction.
The output unit 70b is located on the internal combustion engine E side,
Is located on the anti-internal combustion engine E side rearward of the rear axle 13 in the front-rear direction, that is, on the opposite side of the rear axle 13 from the side where the internal combustion engine E is located. The trochoid type oil pump is provided on a portion of the transmission shaft 71 behind the ball bearing 72.
73 is provided, and the oil sucked through the oil filter 74 is transmitted through an oil passage provided inside the transmission shaft 71 to the transmission portion.
70a etc.

The transmission portion 70a is a cone holder that holds a plurality of cones 75 arranged annularly around the transmission shaft 71 and is movable in the direction of the rotation axis L4 of the transmission shaft 71.
And a drive face 77, which is rotatably coupled to the transmission shaft 71 and whose outer peripheral surface is in contact with each cone 75, and which is rotatably supported on the transmission shaft 71 via a roller bearing 79, and has an inner periphery An electric motor that moves the cone holder 76 in the direction of the rotation axis L4, and a driven face 78 whose surface contacts each cone 75.
80 (see FIGS. 1 and 4). Also, the output unit 70b
Includes an output gear 82 rotatably supported on a transmission shaft 71 via a ball bearing 81 and rotatably coupled to a driven face 78. Further, the continuously variable transmission 70 is provided with an input rotation speed sensor and an output rotation speed sensor (not shown). Based on the rotation speeds detected by these sensors, the throttle valve opening degree and the rotation speed, which are the operating states of the internal combustion engine E, are determined. The rotation of the electric motor 80 is controlled by the electronic control device so that the speed ratio set according to the speed is obtained, whereby the cone holder 76 moves in the direction of the rotation axis L4.

An output gear 82 located rearward of the rear axle 13
Is an intermediate shaft 85 disposed below the transmission shaft 71 and rotatably supported by the transmission case C via a pair of ball bearings 83, 84.
Meshes with a first intermediate input gear 86 provided at the front of the first gear. A first intermediate output gear 87 is provided at the rear of the intermediate shaft 85,
The intermediate output gear 87 is integrally rotatably coupled to a rear portion of a pinion shaft 89 provided with a pinion gear 90 constituting a final reduction gear R2 together with a ring gear 91 (see FIG. 4). The gear meshes with a second intermediate input gear 88 composed of a large-diameter gear. The front part of this pinion shaft 89
The transmission case C is rotatably supported by a reduction case portion 92 provided as a part of the transmission case C via a ball bearing 93, and the rear portion is rotatably supported by the transmission case C via a ball bearing 94. Therefore, the first intermediate input gear 86, the first intermediate output gear 87, and the second intermediate input gear 88 allow the output unit 70 of the continuously variable transmission 70 to operate.
An intermediate reduction gear R1 that reduces the rotation speed of the power from b and transmits the reduced rotation speed to the pinion shaft 89 is configured.

As shown in FIG. 4, the pinion gear 90
Meshes with a ring gear 91 spline-coupled to a differential case 95 housed in a reduction case portion 92,
A final deceleration of 20 rotation speeds takes place. Deceleration case
A left axle tube 96L for accommodating the left rear axle 13L and a right axle tube for accommodating the right rear axle 13R are provided in a left opening and a right opening 92.
The 96Rs are each connected by bolts.

The differential device D includes a differential case 95, a pinion shaft 97 penetrating through the inside of the differential case 95, and a pair of pinion gears 98, 99 fixed to both ends of the pinion shaft 97.
And a pair of left and right side gears 100 and 101 that mesh with both pinion gears 98 and 99. And left and right side gear 10
A left rear axle 13L and a right rear axle 13R are spline-connected to 0 and 101, respectively.

With such a configuration of the transmission M, the power of the crankshaft 20 is transmitted to the clutch 60 via the driven gear 62 meshing with the drive gear 53, and the power of the clutch shaft 61 of the clutch 60 is also eliminated. The transmission is transmitted to the transmission 70a via the transmission shaft 71 of the step transmission 70. Then, a speed change is performed in the speed change section 70a so as to attain a speed ratio set in accordance with the operation state of the internal combustion engine E, and the speed-changed power is transmitted from the output gear 82 via the intermediate speed reducer R1 to the final speed reducer R2. , And further transmitted to the left and right rear axles 13 via the differential device D to drive the rear wheels Wr.

Here, referring to FIG. 2, the crankshaft 20 and the clutch shaft 6 for transmitting the power of the crankshaft 20 to the rear axle 13 will be described.
1. The arrangement of the transmission shaft 71, the intermediate shaft 85, and the pinion shaft 89 will be described. The rotation axis L5 of the intermediate shaft 85 parallel to the rotation axis L1 of the crankshaft 20 is the rotation axis L of the crankshaft 20.
1 and slightly above and to the left of the transmission shaft
71 is located below the rotation axis L4 and near the rotation axis L1. The rotation axis L6 of the pinion shaft 89, which is parallel to the rotation axis L1 of the crankshaft 20, is located diagonally below and to the left with respect to the rotation axis L1.
5 and closer to the rotation axis L1. Therefore, the transmission shaft 71, the intermediate shaft 85, and the pinion shaft 89 occupy positions closer to the rotation axis L1 of the crankshaft 20 in this order. Thereby, in the power unit P,
Mass can be concentrated in the left and right direction, and transmission case C
Can be made more compact.

Next, the effects of the embodiment configured as described above will be described. Since the transmission 70a of the continuously variable transmission 70 is disposed on the internal combustion engine E side with respect to the rear axle 13, the transmission 70a occupying a large weight in the continuously variable transmission 70 is Since the power unit P is located relatively close to the power unit P mounted on the three-wheeled motor vehicle V, the mass is concentrated. Also, the intermediate reduction gear R
1 and the final reduction gear R2 are in a vertical positional relationship, so that both reduction gears R1 and R2 are arranged in parallel in the front-rear direction, and a transmission 70a is provided on the internal combustion engine E side with respect to the rear axle 13. Since the output portions 70b are respectively disposed on the anti-internal combustion engine E side, the distance in the front-rear direction between the output gear 82 and the rear axle 13 can be shortened, so that the continuously variable transmission 70,
The transmission case C that houses the intermediate reduction gear R1 and the final reduction gear R2 can be made compact in the front-rear direction. Further, in the power unit P, the continuously variable transmission 70
Is located further above the intermediate speed reducer R1 above the final speed reducer R2, so that it is located relatively far from the rear axle 13 in the vertical direction. Lowering is prevented.

As a result, in the power unit P, the mass is concentrated and the maneuverability of the three-wheeled motor vehicle V is improved. In addition, since the transmission case C can be made compact in the front-rear direction, the power unit P can be compact in the front-rear direction, and the degree of freedom of arrangement of members arranged around the power unit P increases. Further, it is possible to prevent the minimum ground clearance of the three-wheeled motor vehicle V from being reduced due to the arrangement of the continuously variable transmission 70 of the power unit P.

The crankshaft 20 includes a clutch 60 and a continuously variable transmission in which the clutch shaft 61 and the transmission shaft 71 are coaxial.
Since it occupies a position closer to the rear axle 13 than 70, the center of gravity of the motorcycle V can be lowered. Also, the clutch shaft 61 and the transmission shaft
Since the clutch 60 is coaxial with the crankshaft 20 and the clutch 60 having the clutch shaft 61 is disposed in parallel with the crankshaft 20 in the front-rear direction, the continuously variable transmission 70 is disposed close to the internal combustion engine E in the front-rear direction. Also in this respect, in the power unit P, the mass can be concentrated in the front-rear direction, and the power unit P can be compact in the front-rear direction. As a result, the concentration and the size of the power unit P can be further concentrated and the center of gravity of the three-wheeled motor vehicle V can be lowered, and the running stability is improved.

A cylinder 22 occupying a large space is disposed on the right side of the crankshaft 20, and each of the rotation axes L3, L4, L4 is respectively parallel to the rotation axis L1 of the crankshaft 20.
5, a clutch 60 having L6, a continuously variable transmission 70, an intermediate shaft 85
Since the pinion shaft 89 and the pinion shaft 89 are disposed on the left side of the crankshaft 20, these components of the power unit P can be compactly disposed around the rotation axis L1 of the crankshaft 20, and the cylinder 22 is disposed. In the space formed just behind the cylinder 22 on the side of the vehicle, accessories (for example, an air cleaner) of the internal combustion engine E and components attached to the vehicle body can be arranged. Moreover, the cylinder
Since the center axis L2 of the 22 is substantially horizontal, the center of gravity of the internal combustion engine E can be lowered, and thus the center of gravity of the three-wheeled motor vehicle V can be lowered.

As a result, the center of gravity of the three-wheeled motor vehicle V can be further reduced, and the clutch 60, the continuously variable transmission 70, the intermediate shaft 85 and the pinion shaft 89, which are the components of the power unit P, are connected to the crankshaft. The power unit P can be compactly arranged around the rotation axis L1 around the 20 rotation axes L1, so that the power unit P can be made compact around the rotation axis L1, and components can be arranged using the space formed directly behind the cylinder 22. As a result, the body can be made compact.

Further, a transmission shaft 71, an intermediate shaft 85, and a pinion shaft 89, each having a rotation axis L4, L5, L6 parallel to the rotation axis L1 of the crankshaft 20, are arranged in this order. Occupying a position closer to the power unit P, the mass of the power unit P can be concentrated in the left-right direction, and the size of the transmission case C can be further reduced. As a result, the maneuverability of the three-wheeled motor vehicle V is improved, and the power unit P is also compact in the front-rear direction.

Hereinafter, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
The continuously variable transmission 70 is of a cone type, but may be another single-shaft type transmission such as a swash plate type continuously variable transmission. Although the vehicle is a three-wheeled motor vehicle V, it may be a two-wheeled motor vehicle or a small four-wheeled motor vehicle.

[Brief description of the drawings]

FIG. 1 is a left side view of a main part showing a positional relationship between a body frame and a power unit of a scooter-type three-wheeled motor vehicle on which a power unit of the present invention is mounted.

FIG. 2 is a view of a cross section passing through a center axis of a cylinder as viewed from the back surface, and is a view for explaining a positional relationship between rotation axes of respective shafts.

FIG. 3 is a sectional view taken generally along the line III-III in FIG. 2;

FIG. 4 is a sectional view taken generally along the line IV-IV of FIG. 1;

[Description of Signs] 1 ... front frame, 2 ... rear frame, 3 ... subframe, 4 ... steering mechanism, 5 ... swing arm,
6 Front suspension mechanism, 7 Neidhart mechanism, 8 Plate, 9 Seat, 10 Storage box, 11 Bracket, 12 Bush, 13 Rear axle, 14 Shock absorber, 20
Crankshaft, 21… Crankcase, 22… Cylinder, 23…
Cylinder head, 24 ... Cylinder head cover, 25 ... Piston, 26 ... Connecting rod, 27 ... Combustion chamber, 28 ... Intake passage, 29
... exhaust passage, 30 ... supercharging passage, 31 ... ignition plug, 32 ... supercharger,
33, 34 ... crankshaft holder, 35, 36 ... ball bearing, 37 ... AC generator, 38 ... radiator, 39 ... cooling fan, 40 ... oil pump, 41 ... oil filter, 42 ... timing gear, 43
... Cam shaft, 44 ... Cam gear, 45 ... Support shaft, 46 ... Cam follower group, 47 ... Pull rod group, 48 ... Rocker arm shaft, 49 ... Rocker arm group, 50 ... Intake valve, 51 ... Exhaust valve, 52 ... Supercharging valve,
53: drive gear, 60: clutch, 61: clutch shaft, 62: driven gear, 63, 64: ball bearing, 70: continuously variable transmission, 70a: transmission unit, 70b: output unit, 71: transmission shaft, 72: Ball bearings, 73 oil pump, 74 oil filter, 75 cone, 76 cone holder, 77 drive face, 78 driven face, 79
... roller bearings, 80 ... electric motors, 81 ... ball bearings, 82 ... output gears, 83, 84 ... ball bearings, 85 ... intermediate shafts, 86 ... input gears, 87 ...
Output gear, 88: Input gear, 89: Pinion shaft, 90: Pinion gear, 91: Ring gear, 92: Reduction case, 93, 94 ...
Ball bearing, 95: Differential case, 96L, 96R: Axle tube, 97: Pinion shaft, 98, 99: Pinion gear, 100, 101: Side gear, V: Motorcycle, F: Body frame, P: Power unit, Wf ... front wheel, Wr ... rear wheel, E ... internal combustion engine, M ...
Transmission device, C: transmission case, L1 to L6: axis, R1:
Intermediate reduction gear, R2: final reduction gear, D: differential gear.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F16H 57/02 301 F16H 57/02 301G F term (reference) 3D011 AA04 AD01 AD03 AD11 AD12 AG01 AG03 AH02 AL12 AL21 3D039 AA02 AA04 AA05 AB01 AC01 AC22 AC33 AC64 AD23 3J063 AA01 AB02 AB32 AC01 AC03 BA03 BB41 BB50 CA01 CB41 CD11 CD41

Claims (3)

[Claims] 1. A transmission having an internal combustion engine, a transmission unit to which the power of a crankshaft of the internal combustion engine is transmitted, and an output unit for outputting the power shifted by the transmission unit, wherein the power of the output unit is intermediate. A power unit mounted on a vehicle, comprising: a final reduction gear transmitted through a reduction gear, and a transmission case housing the transmission, wherein the power from the final reduction gear is transmitted to a drive shaft. The intermediate speed reducer and the final speed reducer are accommodated, and the transmission unit is disposed on the internal combustion engine side with respect to the drive shaft, and the output unit is disposed on the anti-internal combustion engine side. A power unit mounted on a vehicle, wherein the transmission is disposed above the intermediate reduction gear disposed above the vehicle. 2. The transmission has a transmission shaft that is drivingly connected to the crankshaft via a clutch having a clutch shaft disposed above the crankshaft and transmits power to the transmission unit, 2. The clutch shaft according to claim 1, wherein the clutch shaft is coaxial with the transmission shaft, and the clutch is arranged in parallel with the crankshaft in a front-rear direction. 3.
A power unit mounted on the vehicle described. 3. The cylinder of the internal combustion engine having a substantially horizontal center axis is disposed on one side in the left-right direction with respect to the crankshaft; 3. The clutch according to claim 2, wherein the clutch, the transmission, and the intermediate reduction gear, each having a rotation axis parallel to the rotation axis of the crankshaft, are disposed on the other side in the left-right direction. Power unit mounted on the vehicle.