KR100921178B1 - Bicycle power train - Google Patents

Abstract

The present invention relates to a power transmission device of a bicycle, and in particular, as the pedal arm including the drive shaft is installed to be eccentric on the power transmission unit, the radius of rotation of the pedal arm is increased in the section where the most force enters the pedal arm during the rotation process. By reducing it, you can get the same rotational force with less force,

The drive radius of the power transmission unit is increased so that an efficient driving force can be obtained with a small force, and the gear ratio is adjusted so that the sprocket wheel can be rotated more than the number of revolutions of the pedal shaft to double the driving efficiency. Relates to a power train.

To this end, the present invention is a drive shaft rotated by each pedal arm connected to both ends,

It includes a power transmission unit for transmitting power to the wheel by rotating by the rotation of the pedal arm in the state installed on the drive shaft,

The drive shaft is installed so as to penetrate at an eccentric position on the power transmission unit, characterized in that any one of the pedal arm and the power transmission unit is provided with a sliding hole in which the fixing piece is inserted, the other.

Bicycle, power transmission, eccentricity, pedal arm, sprocket, turning radius

Description

Power transmission device of bicycles

1 is a perspective view showing the overall coupling state of the present invention

Figure 2 is a simplified exploded perspective view of the pedal arm and power transmission unit and the drive shaft of the present invention

3 is an exploded perspective view of a power transmission unit together with a pedal arm and a drive shaft of the present invention;

Figure 4 is a state in which the drive shaft and the pedal arm is eccentrically installed on the power transmission unit of the present invention Figure 5 is an overall coupling cross-sectional view showing a state in which the present invention is installed on the bicycle frame

6a to 6d are schematic views showing a change in the radius of rotation of the pedal arm during the rotation of the pedal arm on the power transmission unit

<Description of the symbols for the main parts of the drawings>

  100: drive shaft 200: lung cancer

  214: sliding hole 300: power transmission unit

  310: rotating drum 311: ring gear

  312 cover 320 planetary gear

  323: outer planetary gear 324: inner planetary gear

  330: sprocket portion 331: sprocket wheel

  332: driven gear 410: first through

   420: second through plate 500: fixed piece

The present invention relates to a power transmission device of a bicycle, the pedal arm and the power transmission unit to be rotated at the same time by mutually coupled, while forming a coupling portion between the pedal arm and the power transmission unit a certain distance away from the point through which the drive shaft penetrated. By increasing the driving radius applied to the transmission part, a higher driving force can be obtained,

The drive shaft is penetrated so as to be eccentric on the power transmission unit relates to a power transmission device of the bicycle that can be efficiently distributed by changing the rotation radius of the pedal arm rotation.

The present invention also relates to a power transmission device of a bicycle capable of obtaining a higher driving force with less power by allowing the power transmission unit, ie, the sprocket, to rotate more than the rotation of the pedal arm.

The conventional power transmission device of the conventional bicycle has a structure in which the driving force is simply transmitted to the driving shaft when the driver rotates the pedal arm, and the sprocket wheel installed on the driving shaft rotates together with the driving shaft to transmit the rotational force to the rear wheel of the bicycle through the chain. This is done.

In general, a bicycle without a multi-stage gear transmission needs to rotate the sprocket only by the driver's foot force, and since the pedal arms and the sprocket wheel have the same rotation speed, there is a problem in that a lot of force is required when driving uphill.

Moreover, the radius of rotation of the pedal arm around the drive shaft, i.e. the force generated from the user, is large, whereas the sprocket wheel is rotated only by the rotation of the drive shaft in the center, so the driving force efficiency output from the sprocket wheel relative to the amount of force input from the user is increased. This can only be reduced.

Of course, when the multi-stage gear transmission is installed, the gear ratio can be used for driving with a small force. However, the rotation of the sprocket wheel including the pedal arm increases, but the driving speed is slowed.

In order to solve the problem of the power transmission structure of the general bicycle there is a Korean Patent Application No. 2006-0073972 "Power transmission device of the bicycle" invented by the present applicant.

The prior art has a rotational force augmentation driving piece extending outwardly about the driving shaft at one end of the pedal arm and the rotational force augmentation drive piece is fixed to the power transmission pin on the sprocket portion, so that the driving force by the pedal arm is centered. In addition to the drive shaft, it is also transmitted to the power transmission pin, which increases the radius of the force exerted from the driver, thereby obtaining a higher driving force.

The driving force generated from the pedal arm and the sprocket part is finally transmitted to the sprocket through the gear part composed of different gear ratios, so that the sprocket rotates more than the pedal arm, so that a high driving force can be obtained not only with a small force but also with a driving speed. It is characterized in that the problem to be degraded.

However, the prior art also has to be supplemented with the advantages described above.

Specifically, since the pedal arm is always rotated along the trajectory of the circle, further improvement in driving force besides the basic driving force by the pedal cannot be expected.

Therefore, it is necessary to expect improved driving force only by improving the rotational speed of the sprocket through the gear part. Therefore, in order to obtain higher driving force with less force, the structure of the gear unit is inevitably modified, and the structure and manufacturing process of the gear unit may be complicated, thereby increasing the cost of the product.

The present invention has been proposed to solve the problems of the prior art as described above,

By reducing the rotation radius of the pedal arm between the 11 o'clock and 6 o'clock directions, which require a relatively large force during the rotation process, the same rotational force can be obtained with less force due to the reduced radius of the pedal arm. An object of the present invention is to provide a power transmission device for a bicycle capable of exhibiting high driving force on an uphill road.

In addition, by adjusting the gear ratio to increase the number of revolutions of the sprocket relative to the number of revolutions of the pedal arm, it is an object of the present invention to provide a power transmission device of the bicycle that can obtain a high driving force with a small force without deterioration of speed and increase of exercise force.

The power transmission device of the present invention bicycle proposed to achieve the above object,

A pedal arm installed at both ends of the drive shaft and the drive shaft to rotate the drive shaft;

It is installed on the drive shaft and coupled to the pedal arm is rotated by the rotational force of the pedal arm and has a basic configuration including a power transmission for transmitting power to the wheel.

In addition, the driving shaft and the pedal arm of the basic configuration is installed in an eccentric position on the power transmission unit is characterized in that the rotation radius of the pedal arm can be changed in a specific section during the pedal arm rotation process.

In addition, by connecting the rotating drum and the final rotating sprocket with the pedal arm of the power transmission unit through the planetary gear, it is characterized in that to increase the number of revolutions of the sprocket wheel by the gear ratio.

Hereinafter, embodiments of a specific configuration and operation of the present invention will be described with reference to the configuration illustrated in the drawings.

The present invention basically consists of a drive shaft 100, a pedal arm 200, and a power transmission unit 300 as largely shown in FIG.

First, the drive shaft 100 is a general circular rotation shaft as shown in [FIG. 2], and the projection jaw 110 is formed in a flange shape on both sides to prevent interference between components located on the drive shaft 100. Both ends are formed with a polygonal fastening section 120 for fastening with each pedal arm 200 and easy rotational force transmission.

The pedal arm 200 is an element in which the driving force of the bicycle is initially generated, and is coupled to both ends of the fastening section 120 of the drive shaft 100, and the same as that of each fastening section 120 of the drive shaft 100. The through-hole 212 having a cross-sectional shape is formed, the lower end is provided with a footrest 212 on which the foot of the driver is seated.

At this time, the coupling between the power transmission unit 300, which will be described later, between the through-hole 213 and the footrest 212 of any one of the pedal arm (hereinafter referred to as 'first pedal arm' 210) of both pedal arms (200) and A long hole-type sliding hole 214 is formed along the longitudinal direction of the first pedal arm 210 for smooth rotation radius change.

The length of the sliding hole 214 and the distance between the through hole 213 is determined according to the degree of change in the rotation radius of the first pedal arm 210 and the coupling position with the power transmission unit 300 to be described later.

Unlike the first pedal arm 210, the second pedal arm 220 coupled to the other side of the driving shaft 100 is simply penetrated without the sliding hole 214 because the second pedal arm 220 is not coupled to the power transmission unit 300. Only the ball 213 is formed, and the footrest 212 is coupled to be located at a point opposite to the footrest of the first pedal arm 210.

The power transmission unit 300 is a component for transmitting the rotational force generated through the first and second pedal arms 210 and 220 to the bicycle wheels, and again the rotation drum 310 and the planetary gear unit 320 and the sprocket. Division 330 is divided.

First, the rotating drum 310 as shown in [2] and [FIG. 3] is a portion of the first direct transmission of the rotational force of the first pedal arm 210, it takes the form of a disk as a whole, the gear on the inner peripheral surface on one side A ring-shaped ring gear 311 in which the acid is formed is positioned, and on one side of the ring gear 311, the cover 312 of the synthetic resin material is formed through a bolt.

Of course, the rotary drum 310 can be produced as many integrally through a single material without being divided into the cover 312 and the ring gear 311.

In addition, an installation hole 313 through which the drive shaft 100 penetrates is formed in the center of the cover 312, and a bearing B is installed in the installation hole 313. A first through plate 410 is installed to allow separate rotations between the rotating drums 310.

A through hole 411 through which the drive shaft 100 is inserted is formed on the first through plate 410, and a bolt hole 412 for coupling with the planetary gear part 320 to be described later is formed around the through hole.

As the driving shaft 100 penetrates the through hole 411 of the first through plate 410, the rotating drum 310 and the driving shaft 100 are coupled to each other via the first through plate 410. As the 100 can be rotated in the through hole 411 of the first through plate 410, the rotary drum 310 and the drive shaft 100 are rotated separately from each other.

At this time, the through hole 411 is formed in the eccentric position, not the center of the first through plate 410, the drive shaft 100 is eventually coupled to the rotation drum 310 to be eccentric. The reason for the eccentric installation of the drive shaft 100 is for changing the radius of rotation of the first pedal arm 210, and the specific action thereof will be described later in the Actions and Effects column.

In addition, when the first pedal arm 210 is coupled to the upper and lower sides of the installation hole 313 of the rotating drum 310, a fastening hole 314 is formed in communication with the sliding hole 214 of the first pedal arm 210. In addition, a separate fixing piece 500 is inserted into the sliding hole 214 and the fastening hole 314.

The coupling structure between the first pedal arm 210 and the rotating drum 310 may be implemented in the opposite structure to that described above. That is, the sliding groove 214 is formed on the rotating drum 310 and the first pedal arm ( The fastening hole 314 may be formed in the 210 form.

In addition, the fixing piece 500 may also be embodied in a form protruding integrally on the first pedal arm 210 or the rotating drum 310 without being separately separated.

The gear diameter of the ring gear 311 of the rotating drum 310 described above is determined in consideration of the desired number of revolutions of the sprocket 330 through the gear ratio with the planetary gear unit 320 to be described later.

The planetary gear unit 320 is for transmitting the sprocket unit 330 in a state in which the rotational speed of the rotating drum 310 is primarily changed, and the first mounting plate 321 and the second mounting plate 322, It consists of an outer planetary gear 323 and an inner planetary gear 324.

The first mounting plate 321 is in the form of a disk, the entire diameter is smaller than the inner diameter of the ring gear 311 of the rotary drum 310 to be inserted into the ring gear 311, the first through plate ( A first insertion hole 325 through which the drive shaft 100 is inserted is formed at the same line position as the first through hole 411 of 410. That is, the first insertion hole 325 is also formed in the eccentric position, not the center of the first installation plate 321.

In addition, a bolt hole 326 matching the bolt hole 412 of the first through plate 410 is formed around the first insertion hole 325. In the position facing the first mounting plate 321, the second mounting plate 322 is positioned in a state of maintaining a predetermined interval with the first mounting plate 321,

The second mounting plate 322 is in the form of a disk having a diameter substantially the same as the first mounting plate 321, the center of the drive shaft 100, the second of the driven gear 332 of the sprocket portion 330 to be described later is inserted Insertion hole 325 is formed.

The second mounting plate 322 and the first mounting plate 321 are coupled to each other through a rotating shaft 326 located between the respective mounting plates, wherein the two rotating shafts 326 are paired with each other at intervals. A plurality of positions are installed in each of the pair of rotation shafts 326 so that the outer planetary gear 323 and the inner planetary gear 324 interlock with each other.

Accordingly, the planetary gear unit 320 is formed in a state in which the planetary gears 323 and 324 are arranged between the first mounting plate 321 and the second mounting plate 322 as shown in the drawing.

At this time, the gear teeth of the outer planetary gear 323 protrudes from each of the mounting plates 321 and 322 so that the outer planetary gear 323 when the planetary gear part 320 is inserted into the ring gear 311 of the rotating drum 310. ) And the gear teeth of the ring gear 311 to be engaged with the gear teeth of the ring gear 311, the gear teeth of the inner planetary gear 324 is exposed in the second insertion hole 325 of the second mounting plate 322 to be described later. 330 is positioned to engage the driven gear 332.

Of course, the diameter of the second insertion hole 325 of the second mounting plate 322 and the size of the inner and outer planetary gears 324 and 323 and the mounting position of the ring gear 311 of the rotary drum 310, the sprocket According to the diameter of the driven gear 332 of the part 330, it is possible to manufacture a variety of deformation, that is, it can be modified according to the desired number of revolutions of the power transmission unit 300.

The sprocket portion 330 is a portion in which the driving force of the power transmission unit 300 is finally output and transmitted to the bicycle wheel, and the driven gear 332 protrudes from one side of the general sprocket wheel 331.

The driven gear 332 is for transmitting the driving force to the sprocket wheel 331 by interlocking with the planetary gear unit 320, the gear teeth are formed on the outer circumferential surface and the gear diameter is each inner planetary gear of the planetary gear unit 320; 324 is inserted between the inner planetary gears 324 to be engaged with each other.

At this time, the sprocket wheel 331 is made of only one wheel or may be implemented in a multi-stage shiftable form as shown in FIG.

At this time, in the center of the driven gear 332 and the sprocket wheel 331, a fixing hole 333 of the same diameter as the installation hole 313 of the rotary drum 310 is formed, the fixing hole of the driven gear 332 ( The bearing B-1 is inserted into and installed in the 333, and the second through plate 420 having the same structure as that of the first through plate 410 is installed in the bearing B-1.

That is, the second through plate 420 also has a second through hole 421 is formed in the eccentric position and the second through hole 421 is located on the same line as the first through hole 411 of the first through plate 410 A bolt hole 422 corresponding to the bolt holes 412 and 326 of the first through plate 410 and the first mounting plate 321 is formed around the second through hole 421.

As the drive shaft 100 penetrates through the second through hole 421, the sprocket 330 and the drive shaft 100 are coupled to each other through the second through plate 420, and the drive shaft 100 is connected to the second hole ( The sprocket 330 and the drive shaft 100 are rotated separately from each other by being able to rotate within the 421.

In addition, since the second through plate 420 also has the second through hole 421 formed in the eccentric position similarly to the first through plate 410, the driving shaft 100 is installed in the state in which the sprocket 330 is eccentric. Will be.

On the other hand, the second through plate 420 is provided with a hollow tube 423 integrally coupled to the bicycle frame (F) on the rear surface and the hollow tube 423 is positioned to communicate with the second through hole 421 The intermediate portion of the drive shaft 100 is accommodated therein.

On the outer circumferential surface of both ends of the hollow tube 423, a thread S is formed, and the hollow tube 423 is inserted into the bicycle frame F, and the second threaded plate 420 side thread is the bicycle frame F and the screw. It is coupled with the bicycle frame (F) in a combined form.

At this time, one end of the hollow tube 423 protrudes through the bicycle frame F, and the other screw thread is exposed. In this exposed part, a separate fixing cover 600 is extrapolated and mutually screwed to the bicycle frame F. ) And the hollow tube 423 is completed.

Next will be described the assembly process of the present invention made of the above configuration.

As shown in FIG. 2 and FIG. 3, first, bearings B and B-1 are installed in the rotary drum 310 and the sprocket 330, respectively, and the bearings are coupled to the rotary drum 310. In (B), after installing the first through plate 410, the planetary gear part 320, ie, the first and second mounting plates 321 and 322, is inserted into the ring gear 311 of the rotary drum 310.

As the planetary gear part 320 is inserted into the ring gear 311, each of the outer planetary gears 323 exposed to the outside of each mounting plate 321 and 322 is engaged with the ring gear 311, and then the sprocket part When the driven gear 332 of 330 is inserted into the second insertion hole 325 of the second mounting plate 322, each inner planetary gear 324 is engaged with the driven gear 332.

As a result, the assembly between the rotary drum 310, the planetary gear unit 320, and the sprocket unit 330, that is, the assembly of the power transmission unit 300, is completed.

Thereafter, the hollow tube 423 of the second through plate 420 is inserted into the bicycle frame F, and the screw is fastened, and the driving shaft 100 is inserted into the hollow tube 423 to thereby secure one side of the driving shaft 100. ) Passes through the second through hole 421 of the second through plate 420.

In this state, the second transmission plate 420 is inserted into the bearing B-1 in the fixing hole 333 of the sprocket portion 330 so that the power transmission unit 300 assembly is connected to the second passage plate 420. To be combined.

As the power transmission unit 300 is coupled to the second through plate 420, one end of the drive shaft 100 is provided with the first insertion hole 325 and the first through plate 410 of the first installation plate 321. The first through hole 411 is sequentially through.

Then, the bolts 412 of the first through plate 410 and the bolts 326 and the second through plate 420 of the bolt hole 412 of the first mounting plate 321 after that By sequentially penetrating the 422, the rotary drum 310, the planetary gear portion 320, the sprocket portion 330 and the drive shaft 100 are completely coupled to each other, the installation of the power transmission portion 300 on the bicycle frame (F) Will be completed.

In this state, both ends of the fastening section 120 of the driving shaft 100 penetrated from the rotating drum 310 are fitted into the through holes 213 of the first pedal arm 210 and the second pedal arm 220. The coupling between the pedal arm 210 and 220 is also completed.

At this time, after matching the sliding hole 214 formed in the first pedal arm 210 and the fastening hole 314 formed in the rotary drum 310, a separate fixing piece 500 is coupled to the sliding hole 214 and the fastening hole ( By sequentially penetrating through 314, the coupling between the first pedal arm 210 and the rotating drum 310 is made, thereby completing all coupling as shown in FIG.

That is, as shown in FIG. 5, the rotating drum 310 is installed to be rotated separately from the drive shaft 100 through the bearing B and the first through plate 410, and the ring gear of the rotating drum 310 is formed. The outer planetary gear 323 is engaged with the outer planetary gear 323, and the outer planetary gear 323 is connected to the driven gear 332 of the sprocket 330 via the inner planetary gear 324, and the driving shaft 100 and the first are connected to each other. The two pedal arms 210 and 220 are positioned to be eccentrically upward by the distance 'A' from the center of the power transmission unit 300.

Hereinafter will be described the operation and effects according to the present invention made of the above configuration.

First, a process of increasing the rotation ratio of the sprocket wheel 331 to the rotation ratio of the first pedal arm 210 according to the gear ratio between the ring gear 311, the planetary gear 320, and the driven gear 332 of the rotating drum 310 will be described. .

When the driver rotates both pedal arms 210 and 220 while driving, the ring gear 311 of the rotating drum 310 coupled with the first pedal arm 210 rotates and the ring gear 311 rotates. The outer planetary gear 323 and the inner planetary gear 324 interlock with each other and the sprocket 331 rotates along with the driven gear 332 engaged with the inner planetary gear 324.

As the sprocket 331 rotates as described above, the bicycle rear wheel (not shown) connected to the sprocket wheel 331 through a chain (not shown) is finally rotated.

At this time, for example, the gear ratio between the ring gear 311 and the planetary gears 323 and 324 is 10: 1, and the gear ratio between the driven gears 332 of the planetary gears 323 and 324 and the sprocket 330 is 10: 1. Assuming that 1: 5, when the first and second pedal arms 210 and 220 and the rotating drum 310 rotate once, the planetary gears 323 and 324 rotate 10 times.

In addition, the driven gear 332 which is interlocked with the planetary gears 323 and 324 is decelerated five times and the sprocket wheel 331 which rotates together with the driven gear 332 is finally rotated five times. That is, the rotational speed of the sprocket 331 relative to the rotational speed of the pedal arms 210 and 220 is increased by about five times, thereby obtaining a very high driving force improvement effect.

In addition, since the rotation ratio is greatly increased through the planetary gear unit 320 in the middle as described above, not only a large force is required on the uphill road, but also the speed ratio according to the planetary gear unit 320 is very large. Compared with the speed reduction phenomenon, it does not occur much.

Therefore, if the gear ratio is manufactured differently according to the bicycle application field, that is, general use or mountain bike, more suitable driving efficiency can be obtained, which will contribute to the improvement of product quality.

Next will be described the process of changing the radius of rotation of the pedal arm which is another key of the present invention and the effects that occur accordingly.

First, FIG. 6 is a view showing a state before a driver drives the pedal arms 210 and 220. The first pedal arm 210 is positioned to face the 12 o'clock position and the second pedal arm 220 is positioned. Is located opposite to the 6 o'clock position. As described above, the pedal arms 210 and 220 together with the drive shaft 100 are installed to be eccentrically upward by the distance 'A' from the center of the power transmission unit 300.

In addition, in this state, the lower end of the sliding hole 214 of the first pedal arm 210 is positioned where the fixing piece 500 is located, as shown in the enlarged view.

For reference, the circle marked 'orbit' is a rotational trajectory of the pedal arms 210 and 220 assuming that the drive shaft 100 and the pedal arms 210 and 220 are positioned at the center of the power transmission unit 300. It is shown for comparison with the turning radius of the pedal arm which is actually changed.

At this time, the portion of the first pedal arm (210) to which the force is applied (P) and the 'basic trajectory' is in a consistent state and the portion to which the force is applied to the second pedal arm (220) 'A' from the 'orbital' It is located inward by a distance, ie an eccentric distance.

When the driver pushes and rotates the first pedal arm 210 in this state, the rotating drum 310 rotates together with the first pedal arm 210 through the fixing piece 500, and at the same time, the power transmission unit 300. Inside the sprocket wheel 331 is rotated through the above-described rotation ratio change process.

In this case, the first and second pedal arms 210 and 220 rotate about the eccentric drive shaft 100, but the rotation drum 310 rotates around the first through plate 410.

Accordingly, the first and second pedal arms 210 and 220 rotate in an eccentric state on the rotary drum 310, and thus the first and second pedal arms 210 and 220 rotate in the sprocket 331 when the pedal arms 210 and 220 are initially rotated. The output torque (torque) can be obtained with less force than when the existing drive shaft 100 is installed in the center of the rotation drum 310,

The reason for this is explained using the rotational force calculation formula T (rotation force) = F (force) x R (radius) as follows.

For reference, assume that the torque to be obtained is the same as before.

Since the drive shaft 100 of the present invention is eccentrically installed as the 'A' above the center of the rotation drum 310, the distance from the portion P to which the force is applied to the first pedal arm 210 from the center of the rotation drum 310 That is, the 'radius R' is longer by 'A' than when the drive shaft is installed in the center of the rotation drum (310).

Therefore, since the radius R is larger than before, the necessary force F is inevitably reduced.

Of course, the 'radius R' should be calculated from the center of the drive shaft 100, not the center of the rotation drum 310, sprocket 331 is the first through-plate 410 that is the center of the rotation drum 310 Since it is to be rotated to the center, the distance to the center of the rotating drum 310 should be applied to the 'radius R'.

Then, as the first pedal arm 210 rotates to the 6 o'clock position as shown in FIG. 7, the rotation radius thereof gradually decreases, and thus a portion P in which a force is applied to the first pedal arm 210. It is located inward from the 'base track' by 'B'.

Therefore, the radius 'radius R' from the center of the rotation drum 310 is also reduced.

In this case, it may be considered that the 'radius R' is reduced so that the 'force F' is increased, but as the rotation radius decreases, the moving distance of the first pedal arm 210 is reduced,

(이동시간) 공식을 통해 알 수 있듯이 회전반경에 변화에 따른 이동길이가 줄어듬으로써 전체 힘 또한 줄어든다. 따라서 실질적으로 소요되는 힘은 최초에 비해 오히려 줄어들게 된다. F (force) = M (weight) × L (travel length) /

As can be seen from the (travel time) formula, the total force is also reduced by reducing the length of travel as the rotation radius changes. Therefore, the actual force is reduced rather than the original.

Of course, for this purpose it will be made in consideration of the appropriate length of the eccentric distance pedal arm.

Thus, by obtaining a higher rotation radius than the existing one, the rotational force of the pedal arm is reduced from the 11 o'clock to 6 o'clock section, which increases the initial output power while the bicycle takes the most power. The greatest feature of the present invention is to allow the same rotational force to be output from the sprocket wheel 331 even with a smaller force than that.

As such, when the first pedal arm 210 is positioned at 6 o'clock, the first pedal arm 210 needs to be lifted thereafter, and thus more force cannot be applied. However, since the second pedal arm is positioned at 12 o'clock and is pushed with a relatively large force, there is no problem in driving.

In summary, according to the present invention, the rotational radius of the pedal arm is changed in the rotation process as the driving shaft is eccentrically positioned and the rotating drum and the driving shaft are rotated separately, so as to obtain the same rotational force with a small force, as well as power transmission. By increasing the rotation ratio of the sprocket wheel through the gear ratio difference in the wealth, it is possible to obtain a high driving force with much less force than before.

Various features of the present invention described above may be variously modified and combined by those skilled in the art, but such modifications and combinations allow the rotation radius of the pedal arm to be changed during the driving of the bicycle as the drive shaft and the pedal arm are eccentrically installed. In addition, when the power generated from the pedal is transmitted to the sprocket, the gear ratio is used to increase the rotation ratio of the sprocket wheel. You must judge yourself as belonging.

As described above, the power transmission device of the bicycle according to the present invention,

As the drive shaft is eccentrically positioned and the rotating drum and the drive shaft are rotated separately, the rotation radius of the pedal arm is changed during the rotation process, so that the same rotational force can be obtained with less force as well as the difference in gear ratio in the power transmission unit. By increasing the rotation ratio of the sprocket through it is possible to obtain a high driving force with significantly less force than conventional.

Claims (4)

delete A drive shaft 100 rotated by each pedal arm connected to both ends, It includes a power transmission unit for transmitting power to the wheel by rotating by the rotation of the pedal arm in the state installed on the drive shaft, The drive shaft is installed through the position eccentric from the center of the power transmission, One of the pedal arms 200 has a long hole-shaped sliding hole 214 into which the fixed piece 500 of the power transmission unit is inserted, so that the distance between the fixed piece and the drive shaft in the process of rotating the pedal arm (rotation radius). Is changed, but the fixed arm is not coupled to the opposite side of the pedal arm, and no sliding hole is formed. The power transmission unit, The rotating drum 310 is coupled to the pedal arm 200 through the fixing piece 500 to rotate together with the pedal arm, and the driving shaft 100 is inserted through the eccentric position, and the ring gear 311 is provided on one side. and, Mounting plates 321 and 322 which are positioned at a predetermined distance from the ring gear 311 of the rotating drum 310 and the driving shaft 100 penetrates, and are installed on the mounting plate and the ring gear 311 of the rotating drum 310. Planetary gear unit 320 made of a planetary gear (323,324) coupled to and coupled with, A sprocket comprising a sprocket 331 positioned at a predetermined interval with the planetary gear plate and coupled to the sprocket 331 and a sprocket through which a drive shaft passes, and driven gear 332 rotated together with the sprocket in conjunction with the planetary gear of the planetary gear unit. Bicycle power transmission device characterized in that it comprises a portion (330). The method of claim 2, As the bearing is provided in the through hole through which the drive shaft passes, the through plate through which the drive shaft penetrates is installed. And the rotating drum and the sprocket on the through plate are rotated separately from the driving shaft. delete

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