JPH0999884A - Transmission for bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission suitable for a tricycle and a monocycle. SOLUTION: When a tricycle is traveled, a friction body 24 is pressed to a rotary disk 11, and rotation of the rotary disk 11 is prohibited. The acceleration/deceleration ratio is determined by the tooth ratio between the first solar sprocket 12 and the first planetary sprocket 16 and the tooth ratio between the second solar sprocket 7 and the second planetary sprocket 16. The friction body 24 is separated from the rotary disk 11, and the rotation of the rotary disk 11 is allowed. A drive shaft 6 and a front wheel 2 are rotated together with the first solar sprocket 12, and the acceleration/deceleration ratio is 1 in this case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle transmission.

[0002]

As is well known, a general bicycle (two-wheeled vehicle) transmits the rotation of a pedal shaft to a drive wheel through a chain. Then, the transmission has a plurality of sprockets with different diameters stacked and fixed to the shaft of the drive wheel.
The chain is selectively hung on one of these sprockets.

[0003]

However, among bicycles, not only two-wheeled vehicles but also three-wheeled vehicles are rare.
This tricycle includes a large front wheel and two small rear wheels, and a pedal is attached to the front wheel shaft.

In the case of such a three-wheeled vehicle, there is a problem that it is difficult to apply the above-mentioned conventional transmission. Also,
The same applies to unicycles.

Therefore, an object of the present invention is to provide a transmission suitable for a three-wheeled bicycle or a single-wheeled bicycle.

[0006]

In order to solve the above problems, a transmission of the present invention is concentric with a drive shaft of a drive wheel of a bicycle, and a main shaft rotatably supporting the drive shaft. A rotating body rotatably supported by the main shaft, rotation limiting means for limiting rotation of the rotating body, a one-way clutch interposed between the main shaft and the rotating body, and a first shaft rotatably supported by the main shaft and rotating with the main shaft. A sun rotation transmitting body, a first planetary rotation transmitting body that is provided on the rotating body and rotates by transmitting rotation of the first sun rotation transmitting body, and is provided on the rotating body and is fixed to a shaft of the first planetary rotation transmitting body. The second planetary rotation transmitting body that rotates together with the first planetary rotation transmitting body, and is fixed to the drive shaft,
A second sun rotation transmitting body that rotates by transmitting the rotation of the second planetary rotation transmitting body.

Here, in the state where the rotating body is stopped by the rotation limiting means, the rotation of the main shaft causes the rotation of the first sun rotation transmitting member →
The power is transmitted in the order of the first and second planetary rotation transmitters and then the second sun rotation transmitter, whereby the drive wheels fixed to the second sun rotation transmitter rotate.

Further, although the rotating body can be rotated in a state where the stop of the rotating body by the rotation limiting means is released, the rotation of the rotating body with respect to the first sun rotation transmitting body (main shaft) is caused by the one-way clutch. Limited to one direction.

For this reason, when the first sun rotation transmitting body is rotated in a direction opposite to the rotatable direction of the rotation body, that is, in the direction in which the rotation of the rotation body with respect to the first sun rotation transmitting body is prohibited. In this case, this rotating body rotates integrally with the first sun rotation transmitting body, and the torque of this rotating body is transmitted to the second sun rotation transmitting body. As a result, the drive shaft rotates like the first sun rotation transmitter.

Therefore, in this transmission, when the rotating body is stopped by the rotation limiting means, acceleration / deceleration is performed by each rotation transmitting body, and when the stopping of the rotating body is released, the acceleration / deceleration ratio becomes 1.

Even if the rotation limiting means releases the stop of the rotating body, if the first sun rotation transmitting body is rotated in the direction in which the rotation of the rotating body is permitted by the one-way clutch, the rotating body is unique. Since the first and second planetary rotation transmitting bodies of the rotating body freely revolve around the first and second sun rotation transmitting bodies, they rotate about their own axes, and the torque of the rotating body becomes the second rotation. The drive shaft cannot be rotated without being transmitted to the solar rotation transmitting body.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 show one embodiment in which the transmission of the present invention is implemented, and FIG. 3 shows a three-wheeled vehicle to which the transmission of this embodiment is applied.

As shown in FIG. 3, a three-wheeled vehicle 1 has a front wheel 2 that serves as a driving and steering wheel and two rear wheels 3 that serve as driven wheels. Each pedal 4 is provided on the front wheel 2 side. The front wheel 2 is covered with a front wheel cover 5.

A drive shaft 6 as shown in FIG. 1 is fixed to the center of a front wheel 2 of the tricycle 1, and a second sun sprocket 7 is fixed to one end of the drive shaft 6.

The main shaft 8 is passed through the drive shaft 6 and is supported by bearings 9 on both sides of the front wheel cover 5. The pedals 4 are attached to both ends of the main shaft 8.

A rotary disk 11 and a first sun sprocket 12 are passed through the main shaft 8. A one-way clutch 13 is interposed between the main shaft 8 and the turntable 11,
This allows the turntable 11 to rotate in one direction, that is, the tricycle 1
The rotation direction is restricted to the direction opposite to the direction of each pedal 4 to be depressed in order to proceed. First sun sprocket 12
Are fixed to the main shaft 8.

A planetary shaft 14 is provided on the turntable 11 so as to project therefrom. The first and second planetary sprockets 1 are attached to the planetary shaft 14.
5 and 16 through these planetary sprockets 15, 16
Is rotatably supported. These planetary sprockets 15 and 16 are connected to each other.

A first chain 17 is bridged between the first sun sprocket 12 and the first planetary sprocket 15.
Also, the second sun sprocket 7 and the second planetary sprocket 1
A second chain 18 is bridged between the six.

The side wall of the front wheel cover 5 has a rotation limiting portion 21.
Is provided. The rotation limiting section 21 includes a support frame 22, a swing body 23, a friction body 24 fixed to the swing body 23, a coil spring 25, and a wire 26. The material of the friction body 24 is, for example, synthetic rubber.

The right end of the oscillating body 23 is pivotally supported by the support frame 22. The rocking body 23 is urged downward by a coil spring 25. As a result, the friction body 24
Is pressed against the peripheral edge of the turntable 11.

The wire 26 has one end connected to the rocking body 23 and the other end connected to the lever 27. The lever 27 is attached to the handle 28 of the tricycle 1. By rotating this lever 27, this lever 2
When 7 is hooked and fixed to the pin 29, the rocking body 23 is pulled up, and the friction body 24 is separated from the turntable 11.

Now, in such a configuration, the tricycle 1
The friction body 24 is brought into pressure contact with the turntable 11 during traveling of
The rotation of the turntable 11 is prohibited.

In this state, when each pedal 4 is depressed,
The main shaft 8 rotates, and the rotation of the main shaft 8 causes the first sun sprocket 12 → first and second planetary sprockets 15, 16 →
The drive shaft 6 fixed to the second sun sprocket 7 is transmitted in the order of the second sun sprocket 7,
The front wheel 2 rotates.

In this order, the first sun sprocket 1
When the rotation of 2 is transmitted, the ratio of acceleration and deceleration is as follows: the ratio of the number of teeth of the first sun sprocket 12 and the first planetary sprocket 15; and the ratio of the number of teeth of the second sun sprocket 7 and the second planetary sprocket 16. Determined by

When the tricycle 1 travels, the lever 27
Is rotated to separate the friction body 24 from the turntable 11,
The turntable 11 can be rotated.

In this state, the turntable 11 can be rotated, but the one-way clutch 13 inhibits the rotation of the turntable 11 with respect to the first sun sprocket 12 in the same direction as the rotation of the first sun sprocket 12. . For this,
The torque of the first sun sprocket 12 is the first chain 17
Also, even if it is transmitted to the turntable 11 through the first planetary sprocket 15, the turntable 11 cannot rotate independently, but rotates integrally with the first sun sprocket 12. The torque of the turntable 11 is transmitted to the second sun sprocket 7 through the second planetary sprocket 16 and the second chain 18. As a result, the drive shaft 6 and the front wheels 2 rotate similarly to the first sun sprocket 12. The ratio of acceleration / deceleration at this time is 1.

As described above, in the transmission according to the embodiment, the friction bodies 24 are pressed against the rotary disk 11 or separated from the rotary disk 11, so that the sprockets 7, 12, 1 are separated.
It is possible to perform acceleration / deceleration based on the ratio of the number of teeth of 5, 16 or cancel this acceleration / deceleration to set the ratio of this acceleration / deceleration to 1.

Therefore, at the start of running when a large torque must be transmitted to the front wheels 2, the friction body 24 is separated from the rotating disk 11 and the acceleration / deceleration ratio is set to 1, so that the running is started promptly, and then the constant speed is set. When shifting to high-speed running, the friction body 24 is brought into pressure contact with the turntable 11, and each sprocket 7,
Perform acceleration / deceleration based on the ratio of the numbers of teeth 12, 15, 16
You can drive with less loss.

At the start of running, the acceleration / deceleration ratio is set to 1
As a result, since the torque applied to each pedal 4 is reduced, the left and right runout of the front wheel 2 (driving and steering wheel), which tends to increase at the start of traveling, is reduced, and the tricycle 1
Brings the advantage of improving the stability of the. Such an action can be expected when climbing a slope.

FIG. 4 shows another embodiment of the transmission of the invention. Here, the transmission of the present invention is applied to a two-wheeled vehicle.

In the figure, the main shaft 31 is rotatably supported at its both ends by the frame 32 of the motorcycle. The drive shaft 33 passes through the main shaft 31 and rotatably supports the rear wheel 34 of the motorcycle. A second sun sprocket 36 is fixed to one end of the drive shaft 33.

A small sprocket 37 is attached to one end of the main shaft 31.
Also, the first sun sprocket 38 is axially supported with the one-way clutch 35 interposed. The traveling chain 39 is bridged between a small sprocket 37 and a large sprocket (not shown) connected to each pedal of this motorcycle, and the rotation of these pedals is transmitted to the small sprocket 37 through the one-way clutch 35. To do.

A turntable 41 is passed through the main shaft 31. A one-way clutch 42 is interposed between the main shaft 31 and the turntable 41 to limit the rotation of the turntable 41 to one direction. This one-way clutch 42
Rotation is permitted in the same direction as the preceding one-way clutch 35, and the opposite rotation direction is prohibited.

The turntable 41 is provided with the first and second planetary sprockets 43 and 44, and these planetary sprockets 4 are provided.
3,44 are rotatably supported. These planetary sprockets 43 and 44 are connected to each other.

A first chain 46 is bridged between the first sun sprocket 38 and the first planetary sprocket 43, and the second
A second chain 47 is bridged between the sun sprocket 36 and the second planetary sprocket 44.

The rotation limiting portion 48 is fixed to a bicycle frame (not shown). The rotation limiting section 48 includes a support frame 49, a swing body 50, a friction body 51, a coil spring 52,
And a wire 53.

The friction body 51 is urged downward by the coil spring 52 and is in pressure contact with the peripheral edge of the turntable 41. When the wire 53 is pulled up, the friction body 51 separates from the turntable 41.

Here, when the two-wheeled vehicle is traveling, if the friction body 51 is brought into pressure contact with the peripheral edge of the turntable 41 as shown in FIG. 4, the rotation of the small sprocket 37 is changed from the first sun sprocket 38 to the first and second sun sprockets 38. 2 Planetary sprockets 43, 44 →
The power is transmitted in the order of the second sun sprocket 36, and the drive shaft 33 and the rear wheel 34 rotate.

When the wire 53 is pulled up to separate the friction body 51 from the rotary disc 41 to allow the rotary disc 41 to rotate, the one-way clutch 42 causes the rotary disc 41 to rotate with respect to the small sprocket 37. Since the rotation of the small sprocket 37 is prohibited in the same direction as the rotation of the small sprocket 37, the turntable 41 does not rotate independently and the first sun sprocket 3 does not rotate.
8 and small sprocket 37 rotate integrally. Along with this, the second sun sprocket 36 also rotates and the drive shaft 3
3 and the rear wheel 34 will rotate like the first sun sprocket 38.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made. For example,
If the force of pressing the friction body against the turntable can be adjusted and the rotation of the turntable is adjusted, it is possible to perform stepless acceleration / deceleration. Alternatively, instead of a transmission mechanism by a combination of a sprocket and a chain, a combination of a friction wheel and a belt or a transmission mechanism by a gear may be applied.

Further, since its structure is simple, it is suitable for a tricycle and a unicycle.

[0043]

As described above, according to the transmission of the present invention, two-step acceleration / deceleration can be performed depending on whether the rotation limiting means stops or does not stop the rotating body. Moreover, its structure is simple, and it is suitable for a tricycle and a unicycle.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a transmission of the invention.

FIG. 2 is a plan view schematically showing the transmission of FIG.

3 is a perspective view showing a tricycle to which the transmission of FIG. 1 is applied.

FIG. 4 is a side view showing another embodiment of the transmission of the invention.

[Explanation of symbols]

 1 tricycle 2 front wheel 3 rear wheel 4 pedal 5 front wheel cover 6,33 drive shaft 7,36 second sun sprocket 8,31 main shaft 9 bearing 11,41 turntable 12,38 first sun sprocket 13,42 one-way clutch 15, 43 First planetary sprocket 16,44 Second planetary sprocket 17,46 First chain 18,47 Second chain 21,48 Rotation limiter

Claims (3)

[Claims] 1. A main shaft which is concentric with a drive shaft of a drive wheel of a bicycle and which rotatably supports the drive shaft, a rotating body which is supported by the main shaft, and a rotation which limits rotation of the rotating body. Limiting means, a one-way clutch interposed between the main shaft and the rotating body, a first sun rotation transmitting body that is rotatably supported by the main shaft and rotates together with the main shaft, and a first sun rotation transmitting body provided on the rotating body. A first planetary rotation transmitting body that rotates by transmitting rotation, and a second planetary rotation transmitting body that is provided on the rotating body, is fixed to a shaft of the first planetary rotation transmitting body, and rotates together with the first planetary rotation transmitting body. And a second sun rotation transmitting body that is fixed to a drive shaft and that rotates by transmitting rotation of the second planetary rotation transmitting body. 2. A bicycle has front wheels that are drive wheels and rear wheels that are driven wheels, and a main shaft is concentric with the drive shaft of the front wheels and is rotatably supported. The bicycle transmission according to claim 1, wherein the first sun rotation transmitting body and the pedal of the bicycle are fixed to the first sun rotation transmitting body. 3. The rotating body is a disk, and the rotation limiting means is provided with a friction portion that is in pressure contact with the disk that is the rotating body, and the rotation of the disk is limited by the friction between these disks and the friction portion. The bicycle transmission according to claim 1.