KR20080082096A - Two-wheel drive type driving mechanism for cycle - Google Patents

Abstract

A two-wheel drive type driving mechanism for a bicycle is provided to remarkably improve driving stability of the bicycle by properly adjusting rotational speeds of right and left driving wheels mounted to one driving shaft according to radiuses of rotation thereof in curve driving or rotation. A driving shaft(30) is horizontally installed on a support frame(100) through a pair of fixing brackets(33) and bearings(35). At least one driven sprocket(15) is installed at a center of the driving shaft to receive power from a driving sprocket(5) through a chain(20). A pair of driving wheels(50) is installed at right and left sides of the driving shaft respectively to relatively rotate through bearings(53). A pair of driving ratchet sprockets(60), each of which includes an inner ring and an outer ring, transmits power in one direction. The inner ring of the driving ratchet sprocket is coupled inside a hub(55) of the driving wheel. Each of a pair of driving plates(70) is rotated with the driving shaft while being coupled inside an inner diameter unit(25) of the driving shaft through a shaft through hole and has a sprocket receiving unit to restrict the outer ring of the driving ratchet sprocket and a plurality of power transmission protrusions(75) formed between saw teeth on the outer ring of the driving ratchet sprocket.

Description

Two-wheel drive type driving mechanism for cycle

1 is an exploded perspective view schematically showing a drive structure according to the present invention;

Figure 2 is a cross-sectional view showing in detail the coupling structure of the drive wheel portion of one side constituting the drive structure according to the invention,

3 is an exploded perspective view showing an enlarged view of the main components constituting the drive structure according to the present invention.

* Description of the symbols for the main parts of the drawings *

3: pedal 5: driving sprocket

10: crankshaft 15: driven sprocket

20: chain 21: center part

25: small diameter portion 30: drive shaft

33: fixing bracket 35: bearing

50: drive wheel 53: bearing

55: hub 57: tire

60: drive ratchet sprocket 65: tooth

66: shaft through hole 68: sprocket receiving portion

70: drive plate 75: power transmission projection

93: fixing nut 95: cap for cover

100: support frame

The present invention relates to a drive structure for a bicycle, and more particularly to a two-wheel drive type drive structure for a bicycle is mounted on a pair of drive wheels on one drive shaft.

In general, a bicycle has a trapezoidal support frame, a handlepost pivotally fixed to a front upper portion of the support frame, a handle arranged approximately horizontally on the handlepost upper portion, and one mounted through a fork under the handlepost. It consists of a front wheel, a rear wheel mounted to the rear lower portion of the support frame, and a configuration including a saddle fixed to the rear upper portion of the support frame, the crank shaft including a pedal and a driving sprocket installed in the front lower portion of the support frame And a driven sprocket installed at the rear wheel, and the main sprocket and the driven sprocket are connected to each other in a chain to provide a driving force to the rear wheel.

In addition, the driving structure of such a two-wheeled bicycle is to rotate the crankshaft by rotating the crankshaft by applying a force to the pedal while the user is sitting on the saddle, and the driven sprocket connected to the chain by the rotation of the main sprocket. Rotate to allow the bicycle to move forward in such a way that torque in the forward direction acts on the rear wheel.

However, two-wheeled bicycles are difficult to maintain the center of gravity, and also require a minimum speed to maintain the center, and are not desirable for the elderly who are burdened with fitness for reasons such as being unable to remain stationary while the user is on board. There are many problems.

In order to solve the problem of the general two-wheeled bicycle, by providing three or more support points with the ground, a three-wheeled or four-wheeled bicycle that does not require a skilled balance or maintain a certain speed to maintain the center is provided, Unlike two-wheeled bicycles, the elderly can operate bicycles more stably and comfortably.

The three-wheeled or four-wheeled bicycle according to the prior art can be largely divided into a three-wheeled infant's three-wheeled bicycle, and an adult three-wheeled bicycle or four-wheeled bicycle of the rear-wheel drive system.

That is, the tricycle for infants includes one front wheel and a pair of rear wheels, and a crank shaft provided with a pedal is provided with the front wheels to be configured to directly drive the front wheels. The adult tricycle or four-wheeled bicycle includes one or a pair of front wheels and a pair of rear wheels, and a crankshaft including a pedal and a driving sprocket similar to a general two-wheeled bicycle, and a drive shaft on which a pair of rear wheels are installed. It is provided with a driven sprocket, and is composed of a drive structure to provide a rotational force to the drive shaft by connecting the main sprocket and the driven sprocket in a chain.

However, the driving structure of the adult three-wheeled bicycle or four-wheeled bicycle according to the prior art as described above may be no problem when driving straight without the change of direction, but it is necessary to rotate in order to change the driving direction or to adapt to the curved road If there is, there is a problem that smooth rotation is difficult as a pair of drive wheels are directly fixed to both ends of one drive shaft arranged horizontally.

In other words, when driving in a curve or changing direction, the left and right driving wheels installed on the driving shaft rotate in different rotation radii on a plane. Therefore, the driving speed must be adjusted appropriately according to each rotation radius to ensure driving stability. However, as in the case of a general rear wheel drive car, the stability of the driving due to the absence of a means such as a differential gear system that can individually adjust the rotational speed of the left and right drive wheels according to each rotation radius. This deterioration, as well as the situation that there is a problem that can be easily overturned during rapid rotation.

Invented to solve the problems of the prior art as described above,

The present invention provides a two-wheel drive type driving structure for a bicycle having a pair of left and right driving wheels installed on one drive shaft, so that the rotational speed of the left and right driving wheels can be properly adjusted according to each rotation radius during rotation. It aims to do it.

The present invention for implementing this,

It has a central portion of a predetermined diameter and a pair of small diameter portions extending from each side of the central portion to a diameter smaller than the diameter of the central portion, and arranged in the left and right directions while being rotatable through a pair of fixing brackets and bearings left and right on the support frame. A drive shaft installed to be;

At least one driven sprocket installed at the center of the drive shaft and receiving power of the main sprocket through the chain;

Each wheel is composed of a wheel and a tire including a hub, and each of which is installed on the left and right sides of the drive shaft so that relative rotation is free through a bearing inserted into an overlapping portion with the small diameter portion while the small diameter portion of the drive shaft penetrates each hub. A pair of drive wheels;

A pair of left and right drive ratchet sprockets each divided into an inner ring and an outer ring to transmit power only in one direction, and coupled to the inside of the hub of each driving wheel through the inner ring; And

It is provided with a shaft through hole penetrating through the central portion, respectively, and rotates together with the drive shaft in the state coupled to the inside of the small diameter portion of the drive shaft through the shaft through hole,

A sprocket receiving portion having a shape constraining an outer ring of the driving ratchet sprocket on each outside;

A pair of left and right drive plates each having a plurality of power transmission protrusions extending in parallel with the axial direction at outer edge positions of the same distance from the center and positioned between the teeth and the teeth provided on the outer ring of the driving ratchet sprocket; Provides a two-wheel drive type driving structure for a bicycle comprising a.

In addition, the small diameter portion of the drive shaft, the first drive shaft male screw portion of the inner side adjacent to the center portion, the drive wheel mounting portion in the middle of the drive wheel is mounted, and each outer diameter gradually decreases toward the outside, Includes 2 drive shaft screws

The drive plate is provided with a female screw engaging the first drive shaft screw portion in the shaft through-hole, characterized in that the screwed to be in close contact with the side end surface of the central portion.

In addition, the driving wheel coupled to the drive ratchet sprocket through the hub to the center portion of the drive shaft, the drive ratchet sprocket is screwed to maintain the state accommodated in the sprocket receiving portion outside the drive plate, the And a pair of left and right fixing members having a female screw engaged with the second drive shaft screw portion.

In addition, the drive plate coupled to the right side of the drive shaft of the drive plate is screwed counterclockwise, the drive plate coupled to the left side of the drive shaft is screwed clockwise,

The fixing member coupled to the right side of the drive shaft of the fixing member is screwed in the counterclockwise direction, the fixing member coupled to the left side of the drive shaft is characterized in that the screwed in the clockwise direction.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail.

Figure 1 is an exploded perspective view schematically showing a drive structure according to the present invention, Figure 2 is a cross-sectional view showing in detail the coupling structure of the one side driving wheel constituting the drive structure according to the present invention, Figure 3 It is an exploded perspective view showing the enlarged main components constituting the drive structure according to.

As shown in FIG. 1, the two-wheel drive type driving structure for a bicycle according to the present invention is installed in the support frame 100, similar to the driving structure of a general two-wheeled bicycle, and includes a pedal 3 and a driving sprocket 5. The crankshaft 10 and the driven sprocket 15 which cooperate with the main sprocket 5 via the chain 20 are included. However, the driven sprocket 15 is not directly coupled to the drive wheel 50, but is arranged in the left and right directions in a rotatable state through a pair of fixing brackets 33 and bearings 35 on the support frame 100. It is installed in the center part 21 of the drive shaft 30 installed. That is, the drive shaft 30 has a central portion 21 of a predetermined diameter and a pair of small diameter portions extending from the left and right ends of the central portion 21 by a predetermined length smaller than the diameter of the central portion 21, respectively. 25), the driven sprocket 15 is installed in the central portion 21 among the drive shaft (30).

In addition, although not separately illustrated, the driven sprocket 15 installed on the driving shaft 30 may be two or more according to the riding capacity, and correspondingly, two or more crank shafts 10 may be provided. In addition, each driven sprocket 15 is provided at a position on the central portion 21 of the drive shaft 30 so as to be aligned with each driving sprocket 5 included in each crankshaft 10 in a line, and each chain 20. It is possible to transmit power smoothly.

In addition, the driven sprocket 15 is divided into an inner ring and an outer ring, and transmits power only in one direction, and it is preferable to use a known ratchet sprocket which is installed so that the inner ring is integrally coupled to the central portion 21 of the drive shaft 30. Do. This causes the driven sprocket 15 to rotate together to rotate the driven sprocket 5 when the drive shaft 30 is reversely rotated, thereby causing the crank shaft 10 to rotate while the rider does not intend. It is to avoid doing so.

On the other hand, the drive wheels 50 are mounted on the small diameter portions 25 provided on both the left and right ends of the drive shaft 30, respectively. The small diameter portion 25 of the drive shaft 30 may be divided into three parts again. In detail, the first drive shaft male screw portion 26 and the driving wheel 50 of the inner side adjacent to the central portion 21 are mounted. The drive wheel mounting portion 27 and the second drive shaft male screw portion 28 on the outside. And, the diameter of each part constituting the drive shaft 30 is the center portion 21 is the largest, in the order of the first drive shaft male screw portion 26, the drive wheel mounting portion 27, the second drive shaft male screw portion 28, It gradually decreases from the inner side to the outer side.

Specifically, each driving wheel 50 is composed of a wheel and a tire 57 including a hub 55, as shown in Figure 2, the small diameter portion 25 of the drive shaft 30 is a driving wheel ( In the state penetrating through the hub 55 of 50, the bearing 53 is inserted into the left and right bearing 53 in a structure where the driving wheel mounting portion 27 and the hub 55 are overlapped at both sides of each hub 55. Thus, the drive wheel 50 is installed so as not to be directly constrained to the rotation of the drive shaft 30 on the drive wheel mounting portion 27. For reference, the length of the driving wheel mounting portion 27 may be adjusted according to the width of the hub 55 constituting the driving wheel 50 to be mounted.

For reference, in describing the present invention, the outer side means a direction in which the small diameter portion 25 at both ends of the driving shaft 30 is directed based on the respective driving wheels 50, and the inner side means each driving wheel ( On the basis of 50), it means that the centered portion 21 direction of the drive shaft 30 in which the driven sprocket 15 is installed.

In addition, a pair of left and right drive ratchet sprockets 60 coupled to the inside of the hub 55 of each drive wheel 50 are included. As for the driven ratchet sprocket 60, a well-known ratchet sprocket for transmitting power only in one direction is used as the driven sprocket 15 is used. That is, the inner ring 61 and the outer ring 63 are respectively transmitted to transmit power only in one direction, as shown in Figure 2, the inner ring 61 is the inner side of the hub 55 of each drive wheel 50 Is coupled to. In more detail, the male screw 56 formed on the outer circumferential surface portion inside the hub 55 and the female screw 62 formed on the inner circumferential surface of the inner ring 61 are coupled in a screwing manner.

In addition, a pair of left and right driving plates 70 is provided to transfer the rotational force of the driving shaft 30 to the respective driving wheels 50 through the driving ratchet sprocket 60.

As shown in FIG. 3, the driving plate 70 has shaft through-holes 66 passing through the center, respectively, and is coupled to the inside of the small diameter portion 25 of the drive shaft 30 through the shaft through-hole 66. It rotates together with the drive shaft 30 in the state. In addition, the driving plate 70 extends in parallel with the axial direction, respectively, at the outer edge position of the same distance from the center, respectively, and is located between the teeth 65 and the teeth provided in the outer ring 63 of the driving ratchet sprocket 60. It is provided with a plurality of power transmission projections (75).

The drive plate 70 is preferably coupled to the drive shaft 30 in a screwing manner, and specifically, among the small diameter portions 25 of the drive shaft 30, the first drive shaft male screw portion 26 adjacent to the center portion 21 is provided. Screwed). That is, the drive shaft 30 is the first drive shaft male screw 26 of a predetermined length in the position adjacent to the center portion 21 of the small diameter portion 25, as described above, for screwing the drive plate 70 The first drive shaft screw 26 is formed to have a diameter smaller than the diameter of the central portion 21 and larger than the diameter of the drive wheel mounting portion 27. In addition, the shaft through hole 66 provided in the center of each drive plate 70 is formed to a diameter corresponding to the diameter of the first drive shaft male screw portion 26, and the first drive shaft on the inner peripheral surface of the shaft through hole 66; A female screw 67 to be engaged with the male screw portion 26 is provided. On the other hand, due to the large diameter of the central portion 21, the drive plate 70 is located in a state in which the inner surface is in close contact with the side end surface of the central portion (21). Moreover, each drive plate 70 is provided with the sprocket accommodating part 68 formed in the shape which restrains the outer ring 63 of the drive ratchet sprocket 60 at the outer side.

As described above, in a state in which the driving plate 70 is coupled to the first driving shaft male screw portion 26 of the driving shaft 30, the driving wheel 50 in which the driving ratchet sprocket 60 is coupled to the inside of the hub 55 is vertically driven. Inserted so as to be located on the drive wheel mounting portion 27 of the neck portion 25, in this process the power transmission protrusion 75 provided on the drive plate 70 is a tooth 65 and a tooth 65 of the drive ratchet sprocket 60 In addition to being positioned between the), the driving ratchet sprocket 60 is in close contact with the outside of the driving plate 70 so that the driving ratchet sprocket 60 is partially accommodated in the sprocket receiving portion 68 of the driving plate 30. Accordingly, the outer ring 63 of the driving ratchet sprocket 60 is placed in a restrained state by the driving plate 70, and the rotational force of the driving shaft 30 is transmitted to the driving ratchet sprocket 60 through the driving plate 70. The wheel 50 will be able to rotate.

In addition, as the fixing member fastened to the driving shaft 30 to prevent the driving wheel 50 from being moved or moved from the driving shaft 30, the second of the small diameter portion 25 corresponding to both ends of the driving shaft 30; And a pressing fixing nut 93 which is screwed to the drive shaft screw portion 28. The pressure fixing nut 93 has a corresponding female thread for screwing with the second drive shaft screw 28, and a driving wheel coupled with the driving ratchet sprocket 60 through the hub 55 in the screwing process. While pressing the 50 toward the center portion 21 side of the drive shaft 30, the drive ratchet sprocket 60 can be stably maintained in the state accommodated in the sprocket receiving portion 68 outside the drive plate 70. In other words, this is a state in which the power transmission protrusion 75 can stably transmit power while being prevented from escaping from the position between the teeth 65 and the teeth 65 of the outer ring 63 of the driving ratchet sprocket 60. Means to remain. However, the pressing fixing nut 93 should be installed so as not to interfere with the outer ring of the bearing 55 adjacent to the hub 55 as well as the bearing 53 inserted into the hub 55.

In the above, the driving plate 70 coupled to the right side of the driving shaft 30 of the driving plate 70 provided in a pair of left and right are screwed in the counterclockwise direction, the driving plate coupled to the left side of the driving shaft 30 ( 70 is preferably screwed clockwise. This is because the drive shaft 30 mainly rotates in the direction of advancing the bicycle, so that the drive plate 70 screwed with the drive shaft 30 is not released by the rotation of the drive shaft (30).

In addition, the pressing fixing nut 93 coupled to the right side of the drive shaft 30 of the pressing fixing nuts 93 provided in a pair of left and right are screwed in the counterclockwise direction, and the pressing fixing nut is coupled to the left side of the driving shaft 30. The nut 93 is preferably screwed in a clockwise direction, which is for the same reason as the drive plate 70.

In addition, as shown in FIG. 2, the cover cap 95 is coupled to the outside of each hub 55 constituting the driving wheel 50 by a screwing method or the like. This prevents the second drive shaft male screw portion 28 formed at the end of the drive shaft 30 and the pressure fixing nut 93 coupled thereto from being exposed to the outside, which is undesirable in aesthetic view, and in the worst case, the pressure fixing nut. (93) is released to prevent the departure of the second drive shaft screw portion (28). However, in the normal state, the cover cap 95 is coupled to the outside of the hub 55 of each drive wheel 50 to rotate together with the drive wheel 50, the second drive shaft number of the end of the drive shaft 30 It should be installed so as not to interfere with the thread 28.

Referring to the power transmission path of the two-wheel drive type driving structure for bicycles according to the present invention as follows.

First, when a force through a human foot acts on the pedal 3 and the crankshaft 10 rotates, the driving sprocket 5 also rotates.

When the main sprocket 5 rotates, power is transmitted to the driven sprocket 15 through the chain 20, and the drive shaft 30 rotates together with the driven sprocket 15.

When the drive shaft 30 rotates, the left and right driving plates 70 rotate, respectively, in which the driving plate 70 directly restrains the outer ring 63 of the driving ratchet sprocket 60 from the side surface. In addition, the teeth 65 of the outer ring 63 of the driving ratchet sprocket 60 are restrained by the power transmission protrusion 75 of the driving plate 70, thereby rotating the outer ring 63 of the driving ratchet sprocket 60. When the outer ring 63 rotates in the forward direction, that is, in the forward direction, the inner ring 61 of the driving ratchet sprocket 60 is also restrained by the outer ring 63 to rotate together.

In more detail, the drive ratchet sprocket 60 in which the plurality of power transmission protrusions 75 extending in parallel with the axial direction at the outer edge of the drive plate 70 are in close contact with the drive plate 70. As it is arranged to cross the valley between the tooth 65 and the tooth formed in the outer ring 63 of the shape, the slip between the outer ring 63 and the driving plate 70 of the driving ratchet sprocket 60 By blocking the power supply, accurate power transmission is possible.

As the inner ring 61 of the driving ratchet sprocket 60 rotates through the series of power transmission paths, the hub 55 of the driving wheel 50 is finally engaged with the inner ring 61 of the driving ratchet sprocket 60. The forward rotational force is applied to the driving wheel 50 is rotated in the direction in which the bicycle advances, and the bicycle can be driven.

On the other hand, the combination of the driving plate 70 and the driving ratchet sprocket 60 constituting the drive structure according to the present invention as described above performs a role similar to the differential gear device applied to the vehicle. That is, when two left and right driving wheels 50 are mounted on one driving shaft 30, the two driving wheels 50 are not always constrained to rotate at the same rotational speed with the driving shaft 30. That is, each drive wheel 50 is mounted to the drive shaft 30 by a pair of bearings, and as the drive plate 70 and the drive ratchet sprocket 60 are indirectly transmitted with power, one drive shaft ( The two driving wheels 50 mounted on the 30 can be rotated at different rotational speeds.

As a result, when the driving structure according to the present invention is applied, even if the rotation radius of the two left and right driving wheels 50 are different, such as when cornering or turning direction, the rotational speed of each driving wheel 50 depends on the rotation radius. It can be properly adjusted, so that even a three-wheeled or four-wheeled bicycle having a structure in which a pair of left and right driving wheels 50 are mounted on one drive shaft 30 can be stably driven during cornering or turning. will be.

By providing a two-wheel drive type driving structure for a bicycle according to the present invention as described above, the present invention has a structure in which a pair of left and right drive wheels are mounted on one drive shaft, while the rotational speed of the left and right drive wheels at the time of curve driving or rotation, respectively As it can be appropriately adjusted according to the rotation radius of the car, it is possible to obtain the effect of remarkably improving the driving stability, such as natural cornering is possible and the risk of overturning accident is significantly reduced.

While the invention has been shown and described with respect to specific embodiments thereof, those skilled in the art will recognize that various changes and modifications can be made without departing from the spirit and scope of the invention as set forth in the appended claims. Anyone can easily know.

Claims (4)

It has a central portion of a predetermined diameter and a pair of small diameter portions extending from each side of the central portion to a diameter smaller than the diameter of the central portion, and arranged in the left and right directions while being rotatable through a pair of fixing brackets and bearings left and right on the support frame. A drive shaft installed to be; At least one driven sprocket installed at the center of the drive shaft and receiving power of the main sprocket through the chain; Each wheel is composed of a wheel and a tire including a hub, and each of which is installed on the left and right sides of the drive shaft so that relative rotation is free through a bearing inserted into an overlapping portion with the small diameter portion while the small diameter portion of the drive shaft penetrates each hub. A pair of drive wheels; A pair of left and right drive ratchet sprockets each divided into an inner ring and an outer ring to transmit power only in one direction, and coupled to the inside of the hub of each driving wheel through the inner ring; And It is provided with a shaft through hole penetrating through the central portion, respectively, and rotates together with the drive shaft in the state coupled to the inside of the small diameter portion of the drive shaft through the shaft through hole, Each having a sprocket accommodating portion configured to restrain the outer ring of the driving ratchet sprocket, A pair of left and right drive plates each having a plurality of power transmission protrusions extending in parallel with the axial direction at outer edge positions of the same distance from the center and positioned between the teeth and the teeth provided on the outer ring of the driving ratchet sprocket; Bicycle two-wheel drive drive structure characterized in that it comprises a. The method of claim 1, The small diameter portion of the drive shaft, the first drive shaft male portion of the inner side adjacent to the center portion, the drive wheel mounting portion in the middle of the drive wheel is mounted, and the second driving shaft on the outside, each diameter gradually decreases toward the outside Including male thread, The driving plate has a female screw engaging the first drive shaft screw portion in the shaft through-hole, the two-wheel drive type driving structure for a bicycle, characterized in that the screwed to be in close contact with the side end surface of the central portion. The method of claim 2, The second driving screw coupled to the driving ratchet sprocket through the hub toward the center portion of the driving shaft so that the driving ratchet sprocket is screwed to maintain the state accommodated in the sprocket receiving portion outside the driving plate; A two-wheel drive type drive structure for a bicycle further comprising a pair of left and right fixing members having female threads engaged with the drive shaft screw portion. The method according to any one of claims 1 to 3, The drive plate coupled to the right side of the drive shaft of the drive plate is screwed counterclockwise, the drive plate coupled to the left side of the drive shaft is screwed clockwise, The fixing member coupled to the right side of the drive shaft of the fixing member is screwed in the counterclockwise direction, the fixing member coupled to the left side of the drive shaft is screwed in the clockwise direction, characterized in that the bicycle drive type drive structure.

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