JPH037818B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention comprises a power transmission unit including an engine and a case housing a V-belt continuously variable transmission and a speed reducer that transmits the power of the engine to rear wheels. The present invention relates to a power transmission device for a motorcycle in which the unit is mounted and supported on a vehicle body so as to be vertically swingable.

[Prior Art] Conventionally, in a motorcycle, a power transmission unit is composed of an engine and a case that houses a V-belt continuously variable transmission that transmits the power of the engine to the rear wheels, and the unit is attached to the vehicle body so that it can swing vertically. There is a so-called unit swing type that is attached and supported by the In this unit swing type, the distance between the crankshaft and the rear wheel axle is kept as small as possible within the range allowed by the outer diameter of the rear wheel in order to make the car smaller by making the swing arm as short as possible. The distance is set to approximately the radius of the rear wheel. On the other hand, when transmitting power from the crankshaft to the rear axle, the reduction ratio needs to be approximately 1:11 when driving at the top, and for this reason, the V-belt continuously variable transmission described above cannot reduce the speed alone. In this device, one or two intermediate shafts are provided between the crankshaft and the rear wheel shaft to effect deceleration.

Further, the power from the engine is guided to the driven side V-belt wheel through the V-belt, and the wheel shaft is arranged on the same axis as the support shaft of the driven side V-belt wheel. A power transmission device in which a reduction gear is provided on the outside of the wheel and the driven V-belt wheel drives the wheel via the reduction gear is also known, as shown in, for example, Japanese Patent Laid-Open No. 153953/1983.

[Problems to be Solved by the Invention] However, providing one or two intermediate shafts between the crankshaft and the rear wheel shaft as in the former method reduces the distance between the shafts on which the V-belt is suspended, and as a result, the V-belt The number of times the V-belt is repeatedly bent increases, making it susceptible to high temperatures, which reduces the durability of the V-belt.Furthermore, the above-mentioned intermediate shaft is located at the rear of the driven V-belt wheel, and it is difficult to store it. Since the space for this purpose is secured by extending the rear portion of the case, the amount of protrusion of the case in the overall length direction increases as a result.

In the latter case, the bearing supporting the shaft of the driven V-belt wheel and the shaft of the wheel is
Since the bearings are placed outside the wheels and the reducer, the distance between the two bearings becomes longer and there is a greater possibility that the shafts will deflect.Therefore, it is necessary to make the meshing accuracy of the gears for the reducer very strict, and the distance between the two bearings increases. Since the reducer is placed between the bearings of the wheels and the wheels, the distance between the wheels and the bearings of the wheels becomes long. In addition, the bearing itself must be able to handle large loads. It is also possible to apply this device to motorcycles, etc., but in motorcycles, it is common to narrow the rear wheels and place a driven side V-belt wheel on one side and a muffler etc. on the other. However, in the above device, the driven side V is placed on one side with the wheels in between.
Since the belt pulley is arranged and the reducer is already arranged on the other side, the layout of the muffler etc. is quite difficult, and furthermore, it is difficult to transfer the rotational power from the driven side V-belt wheel to the reducer via the centrifugal clutch. However, there was a problem that the layout was difficult.

This invention has been made in view of the above-mentioned problems of the conventional technology, and its purpose is to improve the durability of the V-belt in a V-belt continuously variable transmission and to prevent any adverse effects on the unit case. The present invention provides a power transmission device for a unit swing type motorcycle without protrusions.

[Means for Solving the Problems] In order to achieve the above object, the power transmission device for a motorcycle, etc. of the present invention includes: a first subshaft that transmits rotation of a driven side V-belt pulley of a transmission to a centrifugal clutch; a second subshaft for transmitting the rotation of the centrifugal clutch to an input gear of the reducer; and a rear wheel shaft that protrudes to one side of the case so that the output gear of the reducer is fixed and supports the rear wheel in a cantilever manner. a second countershaft is inserted into the first countershaft, the second countershaft and the rear wheel shaft are arranged on the same axis, and the reduction gear is interposed between the input gear and the output gear. An intermediate shaft supporting idle gears of the machine is disposed in front of the second subshaft, and each gear of the speed reducer is disposed between the driven side V-belt wheel and the rear wheel.

[Function] Since the second countershaft is inserted into the first countershaft and the second countershaft and the rear wheel shaft are arranged on the same axis, the limited range of the unit case is avoided even though the centrifugal clutch is installed. The distance between the V-belts on the driving side and the driven side can be increased, and the rear wheel shaft protrudes from one side of the case so that the rear wheels cantilevered, making it easy to install mufflers, etc. Furthermore, the intermediate shaft that supports the idle gear of the reducer is placed in front of the second countershaft, and each gear of the reducer is placed between the driven side V-belt wheel and the rear wheel, so the unit case is long. This will not cause any problems, and the dead space can be used effectively.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, A is a vehicle body, B is a power transmission unit, 1 is a front wheel, and 2 is a rear wheel.

The power transmission unit B includes an engine b and a case c that houses a power transmission device that transmits the power of the engine b to the rear wheels 2.

Engine b is a two-stroke engine, and its crankshaft 3 faces the inside of case c at the front.

Case C consists of case body C ₁ and cover C ₂ that covers it.
A V-belt continuously variable transmission is housed therein as a power transmission device.

The V-belt continuously variable transmission includes V-belt wheels 4 and 5 on the driving side and the driven side, and a V-belt 6 that connects them.
It is made up of

The drive-side belt pulley 4 is provided on the crankshaft 3 so as to be integrated therewith, and is composed of a fixed member 4a that is immovable in the axial direction and a movable member 4b that is movable in the axial direction opposing the fixed member 4a.

Reference numeral 7 denotes a spherical body provided on the back surface of the movable member 4b, and as this spherical body 7 is displaced outward by centrifugal force as the rotational speed of the crankshaft 3, that is, the movable member 4b increases, the movable member 4b is fixed member 4
It is designed to move to side a.

Thus, the effective diameter of the belt pulley 4 is increased as the movable member 4b moves toward the fixed member 4a, and the rotational speed of the driven-side belt pulley 5 connected via the V-belt 6 is automatically increased. speed up

The belt pulley 5 on the driven side is composed of a fixed member 5a and a movable member 5b in the same manner as that on the main drive side, and has two subshafts, the _first subshaft 10 and the second subshaft, on the outer periphery of the rear wheel shaft 8 on the side of the cover c2. It is provided via a subshaft 9.

The rear wheel shaft 8 has one end connected to the cover of the case c.
The rear wheel ₂ is supported in a cantilevered manner on one end of the rear wheel 2. The rear wheel 2 is pivotally supported by the casing c 2 and is partially supported by the casing c.

The subshafts 9 and 10 are each formed into a cylindrical shape, and the second subshaft 9 on the inside thereof is rotatably fitted to the outer periphery of the rear wheel shaft 8 via a space 25b. The wheel sets 8 are on the same axis.

The first subshaft 10 on the outside is rotatably fitted to the second subshaft 9 on the inside, and the belt pulley 5 is attached to the outer periphery thereof so as to rotate together with the belt pulley 5.

Therefore, the first countershaft 10 is also on the same axis as the rear wheel shaft 8.

The fixed member 5a of the belt pulley 5 on the driven side is the first
The movable member 5b is fixed to the subshaft 10 so as not to move in the axial direction, and the movable member 5b is spline-fitted to the first subshaft 10 so as to be movable in the axial direction.

A spring 12 biases the movable member 5b toward the fixed member 5a.

Therefore, when the effective diameter of the belt pulley 5 on the driven side increases, the V-belt 6 is displaced in the axial direction, so that the movable member 5b resists the spring 12 and the fixed member 5a
, and the effective diameter is reduced.

As a result, the rotation speed of the belt pulley 5 is further increased, and the rotation speed of the first subshaft 10, which rotates integrally with the belt pulley 5, is also increased.

On the other hand, the rotation of the first countershaft 10 is transmitted to the second countershaft 9 via a centrifugal clutch 13.

The centrifugal clutch 13 has a housing 13a fixed to the second countershaft 9, and a plate 3b provided with a shoe 13c fixed to the first countershaft 10.

Therefore, as the rotation of the first subshaft 10 increases, the shoe 13c comes into pressure contact with the housing 13a, the centrifugal clutch 13 is engaged, and rotation is transmitted from the first subshaft 10 to the second subshaft 9.

The rotation of this second countershaft 9 causes the reduction gear chamber 11
The signal is transmitted to the rear wheels 8 via a reduction gear inside.

The reducer chamber 11 is provided in the rear part of the case c so as to be arranged between the belt pulley 5 and the rear wheel 2 supported by the protruding end of the rear wheel shaft ₈ . It is densely structured.

15 is an oil seal that seals the opening on the belt pulley 5 side in the reduction gear chamber 11, and 16 is an oil seal that similarly seals the opening on the rear wheel 2 side.

On the other hand, in the reducer chamber 11, an input gear 17, idle gears 18, 19, and an output gear 20 are provided as a reducer.
are accommodated, and each of these gears 17, 18,
Lubricating oil for lubricating parts 19 and 20 is sealed.

The first input gear 17 in the gear train is loosely fitted to the rear wheel shaft 8, and a gear 21 is integrally provided at its end on the belt pulley 5 side.

This gear 21 meshes with a gear 22 provided at the end of the second countershaft 9, so that the rotation of the second countershaft 9 is first caused by the rotation of the first input gear via these gears 21 and 22. 17.

The rotation of the input gear 17 is sequentially transmitted to the output gear 20 fixed to the rear wheel shaft 8 via the idle gear 18 and the idle gear 19 coaxial therewith.

Further, an intermediate shaft 30 that supports the idle gears 18 and 19 is arranged in front of the first countershaft 10.
Moreover, the gear reduction mechanism is connected to the first and second gears with respect to the rear wheel shaft 8.
By coaxially supporting the secondary shafts 10 and 9,
Since it is arranged between the two, there is no change in the distance between the shafts in the V-belt continuously variable transmission mechanism, that is, between the crankshaft 3 and the rear wheel shaft 8, and there is no need to interpose an intermediate shaft as in the conventional device. No shortening has been done. Therefore, the V-belt does not have an increase in the number of times of repeated bending due to the shortening of the distance between its axes, and therefore does not have the disadvantage of being easily heated to high temperatures, so it can be expected to improve its durability.

In addition, since the intermediate shaft that supports the idle gears 18 and 19 of the reducer is provided forward of the first subshaft 10, the space for storing the idle gears 18 and 19 is also limited to the first subshaft within the case c. This means that the space can be secured in front of the case c, so that the overall length of the case c does not increase due to securing the space as in the conventional case.

Further, the speed reducer is arranged between the V-belt pulley 5 and the rear wheel 2. Therefore, even if the space for accommodating the reduction gear mentioned above protrudes laterally, the protrusion is accommodated in the recess inside the rear wheel, so there is no substantial problem.

[Effects of the Invention] As described above, the power transmission device of the present invention has a power transmission unit configured by an engine, a V-belt continuously variable transmission that transmits the power of the engine to the rear wheels, and a case that houses a speed reducer. In a motorcycle in which the unit is mounted and supported on the vehicle body so as to be able to swing up and down, a first subshaft transmits the rotation of the driven side V-belt pulley of the transmission to a centrifugal clutch, and a reduction gear transmits the rotation of the centrifugal clutch. The second signal is transmitted to the input gear of
a subshaft and a rear wheel shaft to which an output gear of the reduction gear is fixed and supports a rear wheel, a second subshaft is inserted into the first subshaft, and the second subshaft and the rear wheel shaft are the same. Because it is placed on the axis, the distance between the belt wheels on the driving side and the driven side can be increased within the limited range of the unit case even though it is equipped with a centrifugal clutch, which reduces the number of times the V-belt is repeatedly bent. Therefore, the durability of the V-belt can be improved.

In addition, since the intermediate shaft that supports the idle gear of the reducer is placed in front of the first countershaft, there is no need to secure space behind the rear wheel shaft in the case to accommodate the idle gear, and the overall length of the case is reduced. It never gets too big.

Since idle gears can be accommodated within the radial width of the belt wheel, dead space can be used effectively.Furthermore, the weight is not concentrated around the rear wheel, resulting in a better weight balance, and the inertia caused by the swinging of the case is reduced. Less force is generated.

Furthermore, since each gear of the reducer is arranged between the V-belt wheel on the driven side and the rear wheel, even if the space for storing each gear of the reducer protrudes to the side of the case, the protrusion Since it fits inside the recess on the inside of the rear wheel, it is practically not a problem at all, and it does not impose any restrictions on the layout of mufflers or the like placed outside the rear wheel.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the motorcycle of the present invention, Fig. 2 is a side view showing the motorcycle of the present invention;
The figure is a sectional view of the power transmission unit, and FIG. 3 is an enlarged sectional view of the main parts. A...Vehicle body, B...Power transmission unit, b...
Engine, c...unit case, 2...rear wheel,
4... Drive side V-belt wheel, 5... Driven side V-belt wheel, 8... Rear wheel shaft, 9... Second subshaft, 10... First subshaft, 11... Reduction gear room, 13... Centrifugal clutch, 17... Input gear, 18, 19... Idle gear, 20... Output gear, 30... Intermediate shaft.

Claims (1)

[Claims] 1 A motorcycle in which a power transmission unit is constituted by an engine, a V-belt continuously variable transmission that transmits the power of the engine to the rear wheels, and a case that houses a speed reducer, and the unit is mounted and supported on a vehicle body so as to be able to swing vertically. a first countershaft that transmits the rotation of the driven side V-belt wheel of the transmission to the centrifugal clutch; a second countershaft that transmits the rotation of the centrifugal clutch to the input gear of the reducer; a rear wheel shaft to which an output gear is fixed and protrudes to one side of the case so as to cantilever support the rear wheel; a second countershaft is inserted into the first countershaft; wheel sets are arranged on the same axis, an intermediate shaft supporting an idle gear of a reducer interposed between the input gear and the output gear is arranged in front of the second countershaft, and the driven side V A power transmission device for a motorcycle or the like, characterized in that each gear of the speed reducer is arranged between a belt pulley and a rear wheel.