JP4863515B2 - Rotation transmission device and vehicle using the same - Google Patents

Description

  The present invention relates to a rotation transmission device that transmits rotation without interference by a joint portion, and a vehicle such as a two-wheeled vehicle and a three-wheeled vehicle using the rotation transmitting device.

  In conventional front and rear wheel drive motorcycles, the pivot center of a constant velocity joint with the input shaft and output shaft directed in the left-right direction is disposed directly below the steering center (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 3-167092

  In the conventional motorcycle as described above, since only one constant velocity joint is used, the steering range is limited to about ± 32 to 33 °. In addition, if the pivot center of the constant velocity joint is not aligned with the steering center with high accuracy, it will be difficult to turn the steering wheel. Therefore, it is necessary to increase the machining accuracy and assembly accuracy of the constant velocity joint, resulting in high costs. turn into. In addition, in actual motorcycles and bicycles, structural parts such as frames are bent, so it is difficult to maintain a state where the pivot center of the constant velocity joint coincides with the steering center, and the practicality is low. was there.

  The present invention has been made in order to solve the above-described problems, and uses a rotation transmission device capable of transmitting rotation without interference by a joint while suppressing an increase in cost, and the same. The purpose is to obtain a highly practical vehicle.

A vehicle according to the present invention is provided on a main frame, a rear wheel rotatably provided on the main frame, a front frame connected to the main frame so as to be rotatable around a steering shaft, and rotatably provided on the front frame. A joint mechanism that is provided between the front wheels, the main frame, and the front frame, transmits the rotational driving force generated on the main frame side to the front frame side while allowing the front frame to turn relative to the main frame, and the rotational driving force is main. Main side transmission means for transmitting from the frame side to the joint mechanism, and front side transmission means for transmitting rotational driving force from the joint mechanism to the front wheels. The joint mechanism is rotatably provided on the main frame, and is provided by the main side transmission means. A first joint that is rotated by transmission of a rotational driving force, and a front frame; A second joint portion that is rotatably provided and a first joint portion that is rotatably connected to the first universal joint, and a second universal joint. A joint coupling body is rotatably coupled to the second joint and transmits the rotation of the first joint portion to the second joint portion.
The rotation transmission device according to the present invention is provided on a first base and a second base coupled to the first base so as to be rotatable about a main rotation shaft, The rotation of the first rotating body provided on the first base is transmitted to the second rotating body provided on the second base while allowing the rotation of the two bases. A first joint portion rotatably provided on the base body and rotated by transmission of rotation of the first rotating body; a second joint portion provided rotatably on the second base body; The first joint portion is pivotally connected to the first joint portion so as to constitute a joint, and is pivotally connected to the second joint portion so as to constitute the second universal joint. And a joint coupling body that transmits the rotation to the second joint portion.

1 is a perspective view showing a bicycle according to Embodiment 1 of the present invention. It is a front view which shows the coupling mechanism of FIG. It is a front view which shows the coupling mechanism main body of FIG. It is a right view which shows the coupling mechanism main body of FIG. It is sectional drawing which follows the VV line of FIG. FIG. 6 is an explanatory diagram showing a positional relationship between the steering shaft of FIG. 1 and the inner member of FIG. 5. It is explanatory drawing which shows the setting method of the clearance gap g of FIG. It is a side view which shows the bicycle by Embodiment 2 of this invention. It is a perspective view which shows the flame | frame and wheel of the tricycle by Embodiment 3 of this invention. FIG. 10 is a front view showing a connecting portion between the main frame and the front fork body of FIG. 9. FIG. 11 is a perspective view illustrating a partially cutaway connection part of FIG. 10. It is a perspective view which shows the front-end part of the main frame of FIG.

Preferred embodiments of the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a perspective view showing a bicycle according to Embodiment 1 of the present invention. In the figure, a saddle shaft 2 is provided on a main frame 1 as a first base. A saddle (not shown) for a driver to sit on is attached to the upper end portion of the saddle shaft 2.

  A rear wheel 3 as a first rotating body is rotatably connected to the rear end portion of the main frame 1. The main frame 1 is provided with a pair of pedals 4 for rotating the rear wheel 3. The driving force input to the pedal 4 is transmitted to the rear wheel 3 through the main chain 5.

  A steering shaft (handle shaft) 6 as a main rotation shaft is connected to the front end portion of the main frame 1 so as to be rotatable (rotatable). A handle (not shown) is attached to the upper end portion of the steering shaft 6. A front wheel arm 7 is connected to the lower end portion of the steering shaft 6. The front wheel arm 7 is turned integrally with the steering shaft 6. The axis of the front wheel arm 7 is offset with respect to the axis of the steering shaft 6. The front frame as the second base has a steering shaft 6 and a front wheel arm 7.

  A front wheel 8 as a second rotating body is rotatably connected to the lower end portion of the front wheel arm 7. The rotation of the rear wheel 3 is transmitted to the front wheel 8 via the rotation transmission device 9. Thereby, the front wheel 8 is rotated at the same speed as the rear wheel 3.

  The rotation transmission device 9 includes a rear wheel sprocket 10 that rotates together with the rear wheel 3, first and second transmission sprockets 11 and 12 mounted on the side surface of the main frame 1, and between the main frame 1 and the front frame. A joint mechanism 13 mounted on the front wheel, a front wheel sprocket 14 rotated integrally with the front wheel 8, a first transmission chain 15 wound between the rear wheel sprocket 10 and the first transmission sprocket 11, and a second transmission sprocket. 12 and a coupling mechanism 13, and a second transmission chain 16 wound between the coupling mechanism 13 and the front wheel sprocket 14.

  The first and second transmission sprockets 11 and 12 are arranged coaxially and are rotated together. Therefore, by changing the size of the first transmission sprockets 11 and 12, the input rotation can be decelerated or increased and input to the joint mechanism 13. The first transmission chain 15 is disposed in parallel with the main frame 1.

  An attachment arm 18 for attaching the joint mechanism 13 is fixed to the front end portion of the main frame 1. The joint mechanism 13 is disposed between the mounting arm 18 and the front wheel arm 7 so that the axial direction is horizontal and parallel to the left-right direction when the steering shaft 6 is set in the straight direction. The mounting arm 18 is parallel to the front wheel arm 7. Further, the axis of the mounting arm 18 is offset to the opposite side of the front wheel arm 7 with respect to the axis of the steering shaft 6.

  The joint mechanism 13 transmits the driving force input from the second transmission chain 16 to the third transmission chain 17 while allowing the steering shaft 6 to turn. Further, the joint mechanism 13 transmits the driving force from the second transmission chain 16 to the third transmission chain 17 without receiving interference due to the turning of the steering shaft 6. Further, the joint mechanism 13 allows the steering shaft 6 to turn without receiving interference due to transmission of the driving force.

  The main-side transmission means of the first embodiment includes a rear wheel sprocket 10, first and second transmission sprockets 11, 12, and first and second transmission chains 15, 16. The front side transmission means includes a third transmission chain 17 and a front wheel sprocket 14.

  FIG. 2 is a front view showing the joint mechanism 13 of FIG. The joint mechanism 13 includes a joint mechanism main body 19 and a flexible cover 20 that covers an intermediate portion of the joint mechanism main body 19. The flexible cover 20 is made of rubber, for example.

  A first boss 21 is fixed to the mounting arm 18. A first support shaft 22 passes through the first boss 21 and the mounting arm 18. The distal end portion of the first support shaft 22 is inserted into the first end portion of the joint mechanism main body 19. The rotation of the first support shaft 22 is prevented by the first pin 23 penetrating the first boss 21 and the first shaft 22 in the radial direction. The joint mechanism 13 is rotatable with respect to the first support shaft 22.

  When the front wheel 8 is directed straight, a gap g having a predetermined dimension (for example, about 3 mm) exists between the joint mechanism main body 19 and the mounting arm 18. The joint mechanism body 19 is slidable in the axial direction with respect to the first support shaft 22.

  A second boss 24 is fixed to the front wheel arm 7. A second support shaft 25 passes through the second boss 24 and the front wheel arm 7. The distal end portion of the second support shaft 25 is inserted into the second end portion of the joint mechanism main body 19. The rotation of the second support shaft 25 is prevented by the second pin 26 penetrating the second boss 24 and the second support shaft 25 in the radial direction. The joint mechanism 13 is rotatable with respect to the second support shaft 25.

  As described above, the joint mechanism 13 is rotatably supported by the first and second support shafts 22 and 25. The joint mechanism 13 is disposed between the lower end portion of the steering shaft 6 and the front wheel 8.

  3 is a front view showing the joint mechanism main body 19 of FIG. 2, FIG. 4 is a right side view showing the joint mechanism main body 19 of FIG. 3, and FIG. The joint mechanism main body 19 is connected between a first outer member 27 as a first joint portion, a second outer member 28 as a second joint portion, and the first and second outer members 27 and 28. The inner member 29 serving as the joint coupling body, the first transmission pin 30 for transmitting the rotation of the first outer member 27 to the inner member 29, and the rotation of the inner member 29 to the second outer member 28. And a second transmission pin 31.

  The first outer member 27 has a first shaft insertion recess 27a having a circular diameter in section into which the tip of the first support shaft 22 is inserted, a first joint sprocket 27b around which the second transmission chain 16 is wound, And the 1st inner insertion recessed part 27c of the cross-sectional circle diameter in which the 1st end part of the inner member 29 is inserted is provided. The first shaft insertion recess 27a and the first inner insertion recess 27c communicate with each other through a first communication hole 27d having a circular cross section.

  A needle bearing (not shown) is interposed between the first shaft insertion recess 27 a and the first support shaft 22. The needle bearing allows rotation of the first outer member 27 with respect to the first support shaft 22 and allows sliding of the first outer member 27 with respect to the first support shaft 22 in the axial direction.

  The second outer member 28 is wound around the second shaft insertion recess 28a having a circular diameter in section and a third transmission chain 17 into which a tip end portion of the second support shaft 25 and a needle bearing (not shown) are inserted. The second joint sprocket 28b and the second inner insertion recess 28c having a cross-sectional diameter into which the second end of the inner member 29 is inserted are provided. The second shaft insertion recess 28a and the second inner insertion recess 28c communicate with each other through a second communication hole 28d having a circular cross section.

  The first end portion of the inner member 29 is provided with a first ball portion 29a inserted into the first inner insertion concave portion 27c. The first ball portion 29a is provided with a first pin hole 29b. The first transmission pin 30 is passed through the first pin hole 29b. Both end portions of the first transmission pin 30 are fixed to the first outer member 27.

  The second end portion of the inner member 29 is provided with a second ball portion 29c inserted into the second inner insertion recess 28c. The second ball portion 29c is provided with a second pin hole 29d. The second transmission pin 31 is penetrated through the second pin hole 29d. Both end portions of the second transmission pin 31 are fixed to the second outer member 28.

  As shown in FIG. 5, in one cross section, the width dimensions of the first and second pin holes 29b and 29d gradually increase from the middle toward both ends. Thus, the first ball portion 29a can be rotated (bent) by a predetermined angle range (for example, ± 30 °) about an axis parallel to the X axis with respect to the first outer member 27. . Here, the X axis is an axis parallel to the steering shaft 6. Further, the second outer member 28 can be rotated (bent) by a predetermined angle range (for example, ± 30 °) about an axis parallel to the X axis with respect to the second ball portion 29c.

  As described above, the inner member 29 is connected to the first outer member 27 so as to constitute the first universal joint, and is connected to the second outer member 28 so as to constitute the second universal joint. Has been.

6 is an explanatory view showing the positional relationship between the steering shaft 6 of FIG. 1 and the inner member 29 of FIG. The straight direction of the bicycle is the + Z axis direction. In the figure, when the rotation center of the first ball portion 29a relative to the first outer member 27 is C ₁ and the rotation range of the first ball portion 29a relative to the first outer member 27 is ± θ ₁ , The rotation center C ₂ of the second ball portion 29c relative to the outer member 28 is movable along an arc C ₂₁ C ₂₂ centered on C ₁ .

The steering shaft 6 is disposed such that the extension of the axis passes through the sector C ₁ C ₂₁ C ₂₂ . The sector C ₁ C ₂₁ C ₂₂ is a rotatable region of a line segment connecting the rotation centers of the ball portions 29a and 29c. That is, the joint mechanism 13 is arranged so that an extension line of the axis of the steering shaft 6 passes through a rotation region of the inner member 29 with respect to the first outer member 27. Within this region, the axis of the steering shaft 6 may pass anywhere.

Next, FIG. 7 is an explanatory diagram showing a method of setting the gap g in FIG. In the figure, the rotation center of the first ball portion 29a relative to the first outer member 27 is C ₁ , and the position of the axis of the steering shaft 6 is O. When the steering shaft 6 is in the straight traveling direction, the position of the tip surface (end surface farthest from C ₁ ) of the joint mechanism body 19 when the gap g = 0 is assumed to be P ₁ .

When the steering shaft 6 is turned rightward from this state to the maximum, the position of P ₁ moves to P ₂ along an arc centered on O. Therefore, the distance from C ₁ to the distal end surface of the joint mechanism body 19, becomes shorter than before rotation _{(C 1 P 1> C 1} P 2). This is the same when the steering shaft 6 is turned to the left. However, in the actual joint mechanism body 19, the distance from C ₁ to the tip face can not be changed.

On the other hand, in the first embodiment, the distance from C ₁ to the distal end surface of the joint mechanism main body 19 is set in advance to be equal to or less than the length allowed when the steering shaft 6 is turned to the maximum. . For example, when the distance from C ₁ to the front end surface is set to the length of the line segment C ₁ P ₂ , the position of the front end surface of the joint mechanism body 19 when the steering shaft 6 is returned to the straight traveling direction is P ₀ . Accordingly, the gap g may be set to be not less than the interval g ₀ of the line segment P ₁ P ₀ (g ≧ g ₀ ).

  Such a gap g may be secured between the second outer member 28 and the front wheel arm 7. Further, the gap g may be provided separately between the first outer member 27 and the mounting arm 18 and between the second outer member 28 and the front wheel arm 7.

That is, the joint mechanism main body 19 can be displaced in the axial direction in the range of the gap g when the steering shaft 6 is moved straight. On the contrary, if the gap g is not provided, the joint mechanism main body 19 hinders the steering shaft 6 from turning. In order to avoid this, for example, by inserting a spline shaft between the first ball portion 29a and the second ball portion 29c, the axial dimension of the joint mechanism body 19 is set within a range of g ₀ or more. There is also a method of making it variable. That is, the joint mechanism 13 only needs to be capable of at least one of axial displacement and expansion / contraction within a predetermined range.

  Next, the operation will be described. When the rear wheel 3 is rotated by rowing the pedal 4, the rotation of the rear wheel is caused by the rear wheel sprocket 10, the first transmission chain 15, the first transmission sprocket 11, the second transmission sprocket 12, the second It is transmitted to the front wheel 8 via the transmission chain 16, the joint mechanism 13, the third transmission chain 17 and the front wheel sprocket 14. Therefore, this bicycle functions as a front and rear wheel drive bicycle in which front and rear wheels are driven simultaneously.

  In such a bicycle, since the joint mechanism 13 is provided between the main frame 1 and the front wheel arm 7, the rotational driving force is removed from the main frame 1 side except for interference by the joint between the main frame 1 and the front frame. To the front frame side.

Further, since the joint mechanism 13 includes two universal joints, it is not necessary to make the center of one universal joint coincide with the steering center with high accuracy, and the machining accuracy and assembly accuracy can be lowered to reduce the cost. Can be reduced. Further, even if the structural parts of the bicycle are bent, the steering shaft 6 can be turned, so that the practicality as a bicycle is high.
In particular, in the first embodiment, the joint mechanism 13 is disposed so that the extension line of the axis of the steering shaft 6 passes through the rotation region of the inner member 29 with respect to the first outer member 27, and the shaft of the joint mechanism 13 is arranged. Since at least one of displacement in the direction and expansion / contraction is possible within a predetermined range, the cost can be more reliably reduced and the practicality can be further enhanced.

Furthermore, since the joint mechanism 13 has a structure in which two universal joints are combined, the turning angle of the steering shaft 6 can be made larger than in the case of one universal joint.
Furthermore, the minute vibration of the inner member 29 generated when the rotation is transmitted from the first outer member 27 to the inner member 29 is canceled by the rotation transmission from the inner member 29 to the second outer member 28. Only vibrate slightly, and no vibration is transmitted to the front frame side. Thereby, the 1st outer member 27 and the 2nd outer member 28 rotate more reliably at constant speed.

  A stopper that restricts the turning range of the front frame relative to the main frame to a range narrower than the range restricted by the joint mechanism may be provided between the main frame and the front frame. Thereby, it is possible to prevent the operating force of the handle from being directly transmitted to the joint mechanism and to protect the joint mechanism.

In the above example, a bicycle is shown. However, the present invention can be applied to, for example, a motorcycle or an electric motorcycle equipped with a motor on the main frame side.
Furthermore, the present invention can be applied to a three-wheeled vehicle such as a three-wheeled bicycle or a three-wheeled motorcycle having two rear wheels or front wheels.
Furthermore, in the above example, the front and rear wheel drive bicycle is shown, but the present invention can also be applied to a front wheel drive two-wheeled vehicle that transmits the rotational driving force generated on the main frame side only to the front wheels. That is, the pedal shaft or the output shaft of the engine may be the first rotating body.
The rotation transmission device of the present invention can also be applied to vehicles other than two- and three-wheeled vehicles and devices other than vehicles that require rotation transmission.

Embodiment 2. FIG.
Next, FIG. 8 is a side view showing a bicycle according to Embodiment 2 of the present invention. In this example, the main frame 1 is provided with a cylindrical chain housing portion 1a, and a part of the first transmission chain 15 is disposed in the chain housing portion 1a. Further, a first tensioner 32 that applies tension to the first transmission chain 15 is attached to the main frame 1. Further, a second tensioner 33 that applies tension to the third transmission chain 17 is attached to the front wheel arm 7. Other configurations are the same as those in the first embodiment.

  In such a bicycle, since the first transmission chain 15 is accommodated in the chain accommodating portion 1 a, it is possible to more reliably prevent the driver and luggage from interfering with the first transmission chain 15. Further, since the tensioners 32 and 33 are used, the tension of the transmission chains 15 and 17 can be stably maintained, and the driving force can be transmitted to the front wheel 8 more reliably.

Note that a chain accommodating portion for accommodating at least one of the second and third transmission chains 16 and 17 may be provided in at least one of the main frame and the front frame.
Moreover, you may comprise a chain accommodating part by attaching the cover which covers at least any one of the transmission chains 15-17 to a main frame or a front frame.
Further, a tensioner that applies tension to the second transmission chain 16 may be used.

Embodiment 3 FIG.
Next, FIG. 9 is a perspective view showing a frame and wheels of a tricycle according to Embodiment 3 of the present invention. This tricycle is a recumbent type front wheel drive front wheel steering tricycle. In the figure, a pair of rear wheels 42 are rotatably connected to a rear end portion of a substantially T-shaped main frame 41 as a first base. A seat (not shown) on which the driver sits is mounted on the upper portion of the main frame 41. In addition, a pedal shaft hole 41a through which a pedal shaft (not shown) as a first rotating body is inserted is provided in an intermediate portion of the main frame 41.

  An inverted front fork body 43 that is a front frame (second base body) is connected to the front end portion of the main frame 41 so as to be rotatable. A front wheel 44 as a second rotating body is rotatably connected to the lower end portion of the front fork body 43. A steering member (not shown) such as a handle for turning the front fork body 43 is connected to an upper end portion of the front fork body 43.

  10 is a front view showing a connecting portion between the main frame 41 and the front fork body 43 shown in FIG. 9, and FIG. 11 is a perspective view showing the connecting portion shown in FIG. In the figure, a front fork body 43 includes a right fork 45 and a left fork 46 arranged substantially parallel to each other, an upper plate 47 fixed between the upper portions of the forks 45, 46, and a fork 45, below the upper plate 47. And a lower plate 48 secured between 46.

  A front end portion of the main frame 41 is connected between the upper plate 47 and the lower plate 48 so as to be rotatable about a steering shaft (main rotation shaft) 49. A joint mechanism 51 is connected between the main frame 41 and the front fork body 43. The structure of the joint mechanism 51 is the same as that of the joint mechanism body 19 of the first embodiment. The first outer member 27 of the joint mechanism 51 is rotatably held at the front end portion of the main frame 41. That is, a joint mechanism holding hole 41 b is provided at the front end portion of the main frame 41 as shown in FIG. 12, and between the inner peripheral surface of the joint mechanism holding hole 41 b and the outer peripheral surface of the first outer member 27. A bearing (not shown) is interposed between the two.

  The right fork 45 is provided with a support shaft 50 that is inserted into the second shaft insertion recess 28 a of the second outer member 28. A needle bearing (not shown) is interposed between the second outer member 28 and the support shaft 50. The second outer member 28 is rotatable with respect to the support shaft 50.

  Further, the second outer member 28 can be displaced in a predetermined range in the axial direction of the support shaft 50. Further, the joint mechanism 51 is arranged such that an extension line of the axis of the steering shaft 49 passes through a rotation region of the inner member 29 with respect to the first outer member 27.

  A first transmission chain (not shown) as a main transmission means is wound between a first sprocket (not shown) that is rotated integrally with the pedal shaft and the first joint sprocket 27b. Yes. Between the front wheel sprocket (not shown) rotated integrally with the front wheel 8 and the second joint sprocket 28b, a second transmission chain (not shown) is wound as a front side transmission means. The joint mechanism 51 transmits the driving force input from the first transmission chain to the second transmission chain while allowing the front fork body 43 to pivot with respect to the main frame 41.

  In such a tricycle, since the joint mechanism 51 is provided between the main frame 41 and the front fork body 43, the rotational driving force is reduced to the main driving force except for the interference by the joint between the main frame 41 and the front fork body 43. It can be transmitted from the frame 41 side to the front fork body 43 side.

Further, since the joint mechanism 51 includes two universal joints, it is not necessary to align the center of one universal joint with the steering center with high accuracy, and the machining accuracy and assembly accuracy can be reduced, resulting in cost reduction. Can be reduced. Further, even if the structural parts of the bicycle are bent, the steering shaft 49 can be turned, so that the practicality as a bicycle is high.
In particular, the joint mechanism 51 is arranged so that the extension line of the axis of the steering shaft 49 passes through the rotation region of the inner member 29 with respect to the first outer member 27, and the joint mechanism 51 is displaced and expanded in the axial direction. Since at least one of these is possible within a predetermined range, the cost can be more reliably reduced and the practicality can be further enhanced.

  Furthermore, since a transmission mechanism for transmitting the rotation of the pedal shaft to the rear wheel is unnecessary, the structure of the rear part of the tricycle can be simplified, and the height of the seat from the road surface can be reduced. It is particularly suitable for a tricycle.

In the first to third embodiments, the transmission means using the transmission chain is shown. However, the transmission means is not limited to this, and for example, a rod rotated around an axis and a plurality of bevel gears. Combinations may be used.

Claims (5)

main frame,
A rear wheel rotatably provided on the main frame;
A front frame coupled to the main frame so as to be pivotable about a steering shaft;
A front wheel rotatably provided on the front frame;
A joint mechanism that is provided between the main frame and the front frame and transmits the rotational driving force generated on the main frame side to the front frame side while allowing the front frame to turn relative to the main frame;
Main side transmission means for transmitting the rotational driving force from the main frame side to the joint mechanism; and front side transmission means for transmitting the rotational driving force from the joint mechanism to the front wheel,
The joint mechanism is
A first outer member provided rotatably on the main frame, and rotated by the rotation driving force transmitted by the main transmission means;
A second outer member rotatably provided on the front frame;
A first universal joint is rotatably connected to the first outer member, and a second universal joint is rotatably connected to the second outer member. An inner member that transmits the rotation of the first outer member to the second outer member ;
Ball portions are provided at both ends of the inner member,
The intermediate part of the inner member has a smaller diameter than the ball part,
The first and second outer members are each provided with an inner insertion recess into which the ball portion is inserted,
Each ball part is provided with a pin hole,
The pin hole is penetrated by transmission pins whose both ends are fixed to the first and second outer members, respectively.
The width dimension of the pin hole gradually increases from the middle toward both ends, whereby the ball portion is centered on an axis parallel to the steering shaft with respect to the first and second outer members. As a result, it can be rotated only within a predetermined angle range,
An extension line of the axis of the steering shaft passes through a rotation region of the inner member with respect to the first outer member;
The vehicle in which the joint mechanism is capable of at least one of axial displacement and expansion / contraction within a predetermined range . The main transmission means is
A first transmission sprocket mounted on the main frame;
A second transmission sprocket provided coaxially with the first transmission sprocket and rotated integrally with the first transmission sprocket;
A first transmission chain for transmitting the rotation of the rear wheel to the first transmission sprocket;
A second transmission chain for transmitting the rotation of the second transmission sprocket to the first outer member ;
The vehicle according to claim 1, wherein the first outer member is provided with a first joint sprocket around which a second transmission chain is wound. The front side transmission means has a third transmission chain for transmitting the rotation of the second outer member to the front wheel,
Above the second outer member, the second vehicle according to claim 2, wherein the coupling sprocket is provided with a third transmission chain is wound. The vehicle according to claim 2 , wherein the main frame is provided with a chain housing portion that houses at least a part of the first transmission chain. Provided on a first base and a second base coupled to the first base so as to be rotatable about a main rotation axis, and for rotating the second base with respect to the first base. A rotation transmission device that transmits the rotation of the first rotating body provided on the first base to the second rotating body provided on the second base while allowing,
A first outer member rotatably provided on the first base body and rotated by transmission of rotation of the first rotating body;
A second outer member rotatably provided on the second base;
A first universal joint is rotatably connected to the first outer member, and a second universal joint is rotatably connected to the second outer member. An inner member that transmits the rotation of the first outer member to the second outer member ,
Ball portions are provided at both ends of the inner member,
The intermediate part of the inner member has a smaller diameter than the ball part,
The first and second outer members are each provided with an inner insertion recess into which the ball portion is inserted,
Each ball part is provided with a pin hole,
The pin hole is penetrated by transmission pins whose both ends are fixed to the first and second outer members, respectively.
The width dimension of the pin hole gradually increases from the middle toward both ends, whereby the ball portion is an axis parallel to the main rotation axis with respect to the first and second outer members. It is possible to rotate only within a predetermined angle range around
An extension line of the axis of the main rotation shaft passes through the rotation region of the inner member with respect to the first outer member;
The joint mechanism is a rotation transmission device in which at least one of axial displacement and expansion / contraction is possible within a predetermined range .

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