JPH10231013A - Wrapping transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wrapping transmitter, which is improved so as to use a stainless or resin roller chain. SOLUTION: An auxiliary driver 6 is added to a main driver, to which driving force is granted to feed a roller chain 4 somewhat faster than the main driver 4 feeds the chain 4. The auxiliary driver 6 is provided with a powder clutch 61 to absorb excessive driving force on the auxiliary driver 6 as a result of a speed difference between the auxiliary driver 6 and the main driver with the powder clutch 61. In this way, tension to the chain 4 is dispersed to be smaller, so that a stainless or resin roller chain 4 can be used in a longer life.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wrapping transmission device and a device in which a roller chain is wrapped around a sprocket wheel, and is applied to, for example, a bottle conveying device in a bottling process for filling a container such as a bottle with a liquid. And useful devices.

[0002]

2. Description of the Related Art A liquid container made of glass or resin is filled with a liquid for drinking such as juice, and the mouth of the liquid container is capped, sterilized, and bottled to be sent to the next labeling step. In the sterilization process, a winding transmission using a roller chain is generally used as a transport mechanism for the liquid container.

[0003] In this wrapping transmission, as shown in Fig. 10, a drive shaft rotatably driven by a drive unit 2 such as a motor is disposed at one end of a transport path of a liquid container. A rotatable driven shaft is arranged at the end. Sprocket wheels 21 and 22 are rotatably mounted on the drive shaft and the driven shaft, respectively, integrally with the respective shafts. When the driving sprocket 21 is rotated by the driving unit 2, the chain 4 wound around both sprockets 21 and 22 is sent, and the driven sprocket 22 rotates by the feeding of the chain 4. A liquid container (not shown) is detachably attached to the chain 4, whereby the liquid container is sent from the driven shaft side to the drive shaft side together with the feed of the chain 4.

[0004]

In the liquid container transporting apparatus used in the above-described step of bottling beverage liquid, an iron roller chain is conventionally used. However, there is a disadvantage such as rusting of the chain. there were.

Therefore, there has been a demand for changing the material of the chain to a non-rusting material such as stainless steel or resin. However, in the case of the above-described wrapping transmission having a single drive shaft, the tension applied to the chain is large. Therefore, in the case of a chain made of stainless steel or resin having a smaller allowable tension than iron, the chain may be stretched or cut. Therefore, it is impossible to use a stainless steel or resin chain as it is in a conventional apparatus.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wrapping transmission device improved so that a roller chain made of stainless steel or resin can be used.

[0007]

In order to achieve the above-mentioned object, the present invention provides a driving wheel and a driven wheel attached to a driving shaft and a driven shaft, respectively. The bending medial node is sent by being wound and the drive shaft is driven and rotated, and the bending medial node is wound around in a winding transmission in which the driven shaft rotates with the feed. A main driving vehicle driven by the main driving means via a main driving shaft, and a bending medial node provided upstream of the main driving vehicle in a moving path of the bending medial node so as to be sent to the main driving vehicle side. An auxiliary drive vehicle, and a drive shaft for driving the auxiliary drive vehicle, wherein the auxiliary drive vehicle can feed the flexure medial node at a feed speed slightly larger than the feed speed of the flexure mediate node by the main drive shaft. , The driving means or the driving means Excessive acting on the auxiliary drive shaft based on the difference between the auxiliary drive shaft to which the driving force is applied by the auxiliary drive means and the feed speed of the bending mediating node between the auxiliary drive shaft and the main drive shaft. And a buffering means provided between the main driving means or the auxiliary driving means and the auxiliary driving shaft so as to absorb an appropriate driving force.

Further, the present invention, in the above invention, uses a roller chain made of stainless steel or resin.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS.

First, a description will be given of a liquid container transporting device which is a preferred example to which the winding transmission according to the present invention is applied. 8 and 9 show an example of the liquid container transport device.

As shown in FIG. 8 and FIG. 9, this liquid container transfer device tilts the liquid container 1 from a standing state to a horizontal state, sterilizes the back side of the lid at a high temperature, and then returns to a standing state. Mechanism A, a carry-in transport mechanism B for transferring the liquid container 1 in the upright state to the tilt transport mechanism A via the carry-in port B1, and a transport port C from the tilt transport mechanism A.
And an unloading transport mechanism C for receiving and unloading the liquid container 1 in the upright state via the first container 1.

The tilting transport mechanism A includes a driving sprocket 2
A plurality of mounting portions 3 on which the liquid container 1 is mounted are attached at predetermined intervals to a bending bending node (not shown) such as a roller chain wound around the driven sprocket 1 and the driven sprocket 22. The driving sprocket 21 is rotated by the section 2 and the chain is fed, so that the mounting section 3
Is running.

The mounting portion 3 has an L-shape including a mounting table 31 and a side surface holding portion 32 for holding the bottom surface and the side surface of the liquid container 1, respectively, and the side holding portion fixed to the roller chain or the like. The vehicle travels along the traveling rail 5 (omitted in FIG. 9).

The traveling rail 5 has four rails 51, 5
2, 53, 54, are arranged vertically (vertically) near the carry-in transport mechanism B and the carry-out transport mechanism C, and are arranged horizontally (horizontally) between the carry-in transport mechanism B and the carry-out transport mechanism C. ). A pair of inner rails 52 and 53
The outer rails 51 and 54 are disposed near the center of the mounting table 31 on the side of the mounting table 31 and near the edge on the opposite side thereof, respectively. ing. Therefore, the mounting portion 3 and the liquid container 1 mounted thereon are provided with four rails 51, 52, 53, 54.
, And the carry-in transport mechanism B and the carry-out transport mechanism C
8 (at the points P1 and P5 in FIG. 8), it is in an upright state, gradually inclined from the carry-in transport mechanism B to the carry-out transport mechanism C (the points P2 to P4 in FIG. 8), and is in a horizontal state. And gradually returns to the original standing state again.

In FIG. 8, 55 and 56 are support rods for supporting the rails 51 and 52 and the rails 53 and 54, respectively, and 50 is a bracket provided at predetermined intervals.

Next, a description will be given of a wrapping transmission device which is a feature of the present invention.

FIG. 1 schematically shows an example of the wrapping transmission. This wrapping transmission device includes a driving sprocket 21 which is a main driving wheel of a main driving device which is rotationally driven by a driving unit 2 such as a motor M1 which is a driving means, and a driven shaft 2
A flexible bending node such as a roller chain 4 made of stainless steel or resin is wound around a driven sprocket 22 that is rotatably supported by the motor 4 and a chain is formed between the driving sprocket 21 and the driven sprocket 22. An auxiliary driving device 6 for assisting the feeding of the fourth and the like is provided. The chain 4 is composed of the driving sprocket 2
1 is twisted 90 degrees on the upstream side and the downstream side of the driven sprocket 22, so that the sprockets 21, 22 and the auxiliary sprocket 60 are 90 degrees different from each other.

The auxiliary drive device 6 includes an auxiliary drive vehicle, such as an auxiliary sprocket 60, and a buffer means such as a powder clutch (slip clutch) 61. The auxiliary sprockets 60 are arranged in a number corresponding to the transmission torque of the auxiliary drive device 6. Although not particularly limited, for example, two auxiliary sprockets 60 are provided in the example of FIG.

An input shaft 62 such as a powder clutch 61
The power transmission mechanism is connected to the output shaft 20 of the drive unit 2 through a well-known power transmission mechanism such as a gear mechanism, a winding transmission mechanism using a belt or a chain, or a transmission mechanism using a counter shaft. The driving force is transmitted from the driving unit 2 via the.

An output shaft 63 such as a powder clutch 61 and an auxiliary sprocket 60 are respectively provided with sprockets 64.
And the sprocket 65 are integrally attached.
Then, the sprocket 64 and the sprocket 65
The driving force output from the powder clutch 61 and the like is transmitted to the auxiliary sprocket 60.

The auxiliary sprocket 60 rotates the drive sprocket 21 connected to the main drive shaft 23 to rotate the chain 4.
The chain 4 is rotated so that the chain 4 and the like can be fed at a speed slightly faster than the speed at which the chain and the like are sent. As described above, since the chain feed speed of the auxiliary drive device 6 is set to be slightly higher than the chain feed speed of the main drive device, the chain feed speed of the auxiliary drive device 6 is extended to the chain 4 or the like due to the deterioration due to the use of the winding transmission device. Thus, the occurrence of so-called tooth skipping in which the teeth of the auxiliary sprocket 60 do not engage with the holes of the chain 4 or the like is prevented.

The output shaft 6 of the powder clutch 61 and the like
When the shaft torque of No. 3 is equal to or less than the predetermined value, the shaft is directly connected so that the shaft torque of the input shaft 62 and the output shaft torque are equal. On the other hand, when the output shaft torque reaches a predetermined value, the input shaft 6
2 and the output shaft 63, so that the shaft torque of the output shaft 63 does not exceed a predetermined value. This prevents an excessive force from acting on the chain 4 or the like. That is, as described above, since the chain feed speed is slightly different between the auxiliary drive device 6 and the main drive device, a difference in the drive torque occurs between the respective drive devices due to the speed difference. It is adapted to be absorbed by the slip of 61.

In the case where the auxiliary drive device 6 is not driven so that the chain feed speed of the auxiliary drive device 6 can be slightly increased as in the present embodiment, the chain 4 and the like are extended. In this case, the positions of the holes of the chain 4 and the like and the teeth of the auxiliary sprocket 60 are displaced, and not only the tooth jump occurs, but also the tension of the chain 4 and the like decreases, and the liquid container 1 and the like cannot be transported. Inconvenience occurs.

Also, as in this embodiment, the powder clutch 61
If the configuration is such that the torque difference is not absorbed by the above, the tension of the chain 4 and the like in the portion between the driving sprocket 21 and the auxiliary sprocket 60 becomes too large, and the chain 4 and the like are cut. Inconvenience that it occurs.

FIGS. 2 and 3 show an embodiment of the auxiliary driving device 6 applied to the device shown in FIG. In this embodiment, the drive unit 2 (not shown) is connected to the auxiliary drive unit 6 via the counter shaft 70 that passes through the lower space such as the chain 4 in the tilting transfer mechanism A of the liquid container transfer device (see FIG. 1). ) Is transmitted. The end of the counter shaft 70 on the side of the auxiliary drive device 6 is inserted into a bevel gear box 71 fixed to a partition plate that defines a lower space such as the chain 4. It is connected to an input shaft 62 of the powder clutch 61 via a sleeve 72.

The powder clutch 61 is mounted on a bracket 81 fixed to a support base 80. Also,
A shaft 67 serving as an auxiliary drive shaft connecting the auxiliary sprocket 60 and the sprocket 65 fixed integrally with the auxiliary sprocket 60 includes a bracket 82 fixed to the support base 80 and a transport surface in the tilting transport mechanism A of the liquid container transport device. It is supported by a bearing constituted by a bracket 83 fixed on a top plate directly below.

In FIG. 2, a part of the chain 4 and the like are omitted, and in FIG. 3, the running rails 51, 52, 53, 54 are shown.
Are abbreviated.

FIG. 4 shows that the liquid container 1 is filled with the beverage liquid, the liquid container 1 is covered, and the back side of the lid is tilted at a high temperature to disinfect the liquid container 1 in a high-temperature sterilization process. An example layout of the device is shown. In this layout example, the carry-in port B1 is connected to the carry-out port C1.
The transport path of the container leading to is bent at an angle of 90 ° on the way, and is not particularly limited. For example, the auxiliary driving device 6 is installed near the point where the transport path is completely bent toward the unloading port C1.

On both sides of the transport path, an operation and control panel 84 for operating the liquid container transport device and controlling the device, an emergency stop switch 85 for stopping the entire device in an emergency, and for cleaning the liquid container 1 A shower nozzle 86 for jetting the washing water, an oil supply device 87, and various other sensors (not shown) are provided. In FIG. 4, the chain 4 and the like are omitted, and only a part of the pair of rails 52 and 53 inside the traveling rail 5 is shown.

FIG. 5 schematically shows another example of the wrapping transmission. The winding transmission shown in FIG. 5 is different from the above-described device shown in FIG. 1 in that a driving unit 2A such as a motor M1 which is a driving means for driving a main driving device and an auxiliary driving device which drives an auxiliary driving device 6 are provided. The speeds of the auxiliary drive unit 2B such as the motor M2 and the speed of the motor M1 and the motor M2 are synchronized so that the chain feed speed of the auxiliary drive device 6 can be slightly higher than the chain feed speed of the main drive device. A tuning means 2C is provided, and the driving sprocket 21 and the auxiliary sprocket 60 are respectively driven by the individual motors M1 and M2 and the like.
Thus, the auxiliary drive device 6 is tuned and rotationally driven so that the chain feed speed of the main drive device may be slightly higher than the chain feed speed of the main drive device. Other configurations are the same as those of the above-described wrapping transmission having the configuration shown in FIG. 1, and thus the same reference numerals are given and the detailed description is omitted.

The tuning means 2C is constituted by an inverter device or the like, and is capable of adjusting the power supplied to the motor M1 and the like and the motor M2 and the like.

Further, the motor M2 and the like are provided with the entire chain 4 and the like in consideration of a case where the device is operated from a stopped state, a case where the driving force of the auxiliary driving device 6 cannot be obtained due to a failure of the powder clutch 61 and the like. At a predetermined feed rate.

The input shaft 62 such as the powder clutch 61 of the auxiliary drive device 6 is connected to a well-known power transmission mechanism such as a gear mechanism, a winding transmission mechanism using a belt or a chain, or a transmission mechanism using a counter shaft. Through the output shaft 25 of the auxiliary drive unit 2B. The driving force output from the output shaft 63 such as the powder clutch 61 is
Auxiliary sprocket 60 via sprocket 65, shaft 67, sprocket 64, roller chain 66, etc.
Is transmitted to

The powder clutch 61 and the like are the same as those shown in FIG.
When the output shaft torque reaches a predetermined value, a slip occurs between the input shaft 62 and the output shaft 63 as in the device shown in FIG. The drive torque difference caused by the difference in the feed speed is absorbed, and the motor M2 and the like of the auxiliary drive unit 2 are protected when the chain 4 or the like is caught during operation of the apparatus. Therefore, if the powder clutch 61 and the like are not provided, there is a problem that the chain 4 and the like are cut or the motor M2 and the like are damaged when the chain 4 and the like are caught.

FIG. 6 shows an embodiment of the auxiliary driving device 6 applied to the device shown in FIG. In this embodiment, an auxiliary drive unit 2B such as a motor M2 is provided in a lower space of the chain 4 or the like in the tilting transfer mechanism A of the liquid container transfer device.
Is stored.

The motor M2 and the like are mounted on a bracket 88 fixed to the support base 80. The shaft 67 serving as an auxiliary drive shaft is supported by a bearing constituted by a bracket 89 fixed to the front surface of the liquid container transfer device and a bracket 83 fixed to a top plate just below the transfer surface.

In FIG. 6, the running rails 51, 52,
53 and 54 are omitted.

Next, based on the example of the apparatus shown in FIG. 7, the tension of the roller chain 4 and the like in the liquid container conveying apparatus to which the winding transmission according to the present invention is applied is calculated.
A description will be given of a result of performing a tension calculation for the conventional device shown in FIG. 10.

First, as a comparison object, a calculation result of a conventional liquid transfer apparatus will be described with reference to FIG. In the conventional device shown in FIG. 10, the auxiliary drive device 6 is not provided. In FIG. 10, L1 (L7), L
2, L3 (L5) and L6 are the length of each part, respectively, 9.75m, 2.24m, 3.25m and 1.57
m. Also, T1, T2, T3, T4, T5, T6
And T7 are the tensions of the chain 4 and the like in each part of the apparatus shown in FIG. 20kg /
m, the weight W of the chain 4, etc., is 8.9 kg / m, the angle coefficient α of the part where the transfer route is bent by 90 ° is 1.55, the transfer speed is 23 m / min, the speed coefficient K is 1.2, and the friction coefficient is f
Is 0.25 and the twist coefficient K1 is 0.15, T
1 to T7 are respectively obtained by the following formulas. T1 = W × L1 × f = 8.9 × 9.75 × 0.25 = 21.7 (kgf) T2 = {T1 + (W × L2 × f)} × α = {21.7+ (8.9 × 2.24 × 0.25) × 1.55 = 41.4 (kgf) T3 = {T2 + (W × L3 × f)} × K1 = {41.4+ (8.9 × 3.25 × 0. 25)｝ × 1.15 = 56 (kgf) T4 = 1.1 × 56 = 62 (kgf) T5 = T4 + ｛(W + M) × L5 × f｝ × K = 62 + ｛(8.9 + 20) × 3.25 × 0.25)｝ × 1.15 = 89 (kgf) T6 = [T5 + ｛(W + M) × L6 × f｝] × α = [89 + ｛(8.9 + 20) × 1.57 × 0.25｝] × 1.55 = 156 (kgf) T7 = T6 + {(W + M) × L7 × f} = 156 + {(8.9 + 20) × 9.75 × 0.25)} = 226 (kgf) Tmax = K × T7 = 1.2 × 226 = 271 (kgf) Accordingly, the tension acting on the chain 4 and the like of the liquid container transport device shown in FIG. 10 is maximum at the point of contact with the drive sprocket 21, and the value Tmax is 271 kgf.
With this value, if a chain made of stainless steel or resin is used for the chain 4 or the like, the chain 4 or the like is cut off, so an iron chain must be used.

In the same manner, the tension of the roller chain 4 and the like was calculated for the liquid container transfer device as an application example of the present invention provided with the auxiliary drive device 6 as shown in FIG. 21 and the tensions T10 and T at respective points of contact with the auxiliary sprocket 60
11 is 99 kgf and 89 kgf. Based on these values, assuming that the radius of the driving sprocket 21 and the radius of the auxiliary sprocket 60 are 12.75 cm and 6.5 cm, respectively, the setting of the driving torque in the driving sprocket 21 and the auxiliary sprocket 60 is 5.
8 kgm and 12.6 kgm. Torque setting for auxiliary sprocket 60 = 89 kgf × 0.065 m = 5.8 kgm Torque setting for driving sprocket 21 = 99 kgf × 0.1275 m = 12.6 kgm Therefore, in the liquid container transporting apparatus to which the present invention is applied, FIG.
Compared with the conventional device shown in FIG. 0, the tension acting on the chain 4 and the like is dispersed, and the torque setting of the drive unit 2A and the auxiliary drive unit 2B is small, so that a chain made of stainless steel or resin can be used. Becomes Further, in the example in which this calculation is performed, the torque at which the powder clutch 61 and the like start slipping may be set to 5.8 kgm.

According to the above embodiment, the roller chain 4
In addition to the main drive, the speed of the chain 4 is slightly higher than the speed at which the main drive sends the chain 4 or the like.
Drive device 6 to which a driving force is applied so as to be able to send
And an auxiliary driving device 6 is provided with a powder clutch 61 and the like, and an excessive driving force generated in the auxiliary driving device 6 due to a feed speed difference between the auxiliary driving device 6 and the main driving device is controlled by the powder clutch 61 and the like. Since the tension is applied to the chain 4 and the like, the tension of each part of the chain is reduced, so that the roller chain 4 or the like can be made of stainless steel or resin, and the life of the chains can be reduced. Can be extended.

When the auxiliary drive device 6 and the main drive device are individually provided with motors and the like, the same method as in the above embodiment can be achieved by a method of controlling the torque of the motor of each drive device by using a servo motor for each. Although an effect can be obtained, according to the above-described embodiment, the torque difference between the respective driving devices is absorbed by the powder clutch 61 or the like, so that the torque control of the respective driving devices can be performed more easily. In addition, an excellent effect that an inexpensive device can be provided can be obtained. That is, the method using the servomotor has the disadvantage that the torque control is complicated and the device becomes expensive as compared with the above embodiment.

In the above embodiment, the wrapping transmission is composed of the roller chain 4 and the sprocket wheel 2.
Although the configuration is made up of the combination of 1, 2, 60, it is not limited to this, but may be a combination of a timing belt and a gear, or a combination of a rubber belt and a pulley.

Further, in the above embodiment, an example was described in which the wrapping transmission device was used as a transport device for a liquid container. However, the present invention is not limited to this, and the present invention distributes the load of tension acting on a chain or the like. Thus, the present invention can be applied to a power transmission device that needs to reduce the tension of a chain or the like and reduce the driving torque generated by a drive unit for feeding the chain or the like.

Further, in the above embodiment, the buffer means is the powder clutch 61. However, the present invention is not limited to this. When the shaft torque of the output shaft is equal to or less than a predetermined value, the shaft torque of the input shaft and the output shaft torque are reduced. When the output shaft torque reaches a predetermined value, a slip occurs between the input shaft and the output shaft, and the output shaft operates so that the shaft torque does not exceed the predetermined value. Anything can be used.

[0046]

According to the present invention, since the tension acting on the bending mediator is dispersed and the tension of each part is reduced, a stainless steel or resin chain can be used as the bending mediator. , The life of those chains can be extended.

Further, according to the present invention, as compared with a method using a servomotor, which has a drawback that the torque control is complicated and the device becomes expensive, the torque control of each drive device can be performed easily and an inexpensive device can be provided. This has the effect that it can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a configuration of a wrapping transmission according to the present invention.

FIG. 2 is a perspective view showing an example of an auxiliary driving device applied to the winding transmission device shown in FIG.

FIG. 3 is a side sectional view showing an example of an auxiliary drive device applied to the winding transmission device shown in FIG. 1;

FIG. 4 is a layout diagram of an example of a liquid container transport device suitable for applying the wrapping transmission device according to the present invention.

FIG. 5 is a schematic view showing another example of the configuration of the wrapping transmission device according to the present invention.

6 is a side sectional view showing an example of an auxiliary driving device applied to the winding transmission device shown in FIG. 5;

FIG. 7 is a schematic plan view showing an example of a device for calculating tension and torque in the wrapping transmission according to the present invention.

FIG. 8 is a schematic plan view showing an example of a suitable liquid container transport device to which the wrapping transmission device according to the present invention is applied.

FIG. 9 is a schematic perspective view of the liquid container transport device.

FIG. 10 is a schematic view showing a configuration of a conventional wrapping transmission.

[Explanation of symbols]

 Reference Signs List A tilting transport mechanism B carry-in transport mechanism B1 carry-in port C carry-out transport mechanism C1 carry-out port 1 liquid container 2, 2A drive unit (drive means) M1, M2 motor 20, 25 output shaft 21 drive sprocket 23 main drive shaft 22 Driven sprocket 24 driven shaft 2B auxiliary driving unit (auxiliary driving unit) 2C tuning unit 3 mounting unit 31 mounting table 32 side holding unit 4 roller chain (bending medium node) 5 running rail 51, 52, 53, 54 rail 55, 56 Support rod 50 Bracket 6 Auxiliary drive device 60 Auxiliary sprocket 61 Powder clutch (buffer) 62 Input shaft 63 Output shaft 64,65 Sprocket 66 Roller chain 67 Shaft (auxiliary drive shaft) 70 Counter shaft 71 Bevel gear box 72 Sleeve 80 Support 81, 82, 83, 88 , 89 Bracket 84 Operation / control panel 85 Emergency stop switch 86 Shower nozzle 87 Refueling device

Claims (2)

[Claims] 1. A flexible ring-shaped bending medium node is wound around a driving wheel and a driven wheel attached to a driving shaft and a driven shaft, respectively, and the driving shaft is driven to rotate. In the wrapping transmission device in which the bending medial node is fed and the driven shaft rotates with the feed, the bending medial node is wound and driven by a main driving unit via a main driving shaft. A driving vehicle; an auxiliary driving vehicle provided to send the bending medial node to the main driving vehicle side on the upstream side of the main driving vehicle on the moving path of the bending mediating node; and a drive for driving the auxiliary driving vehicle. An auxiliary driving means separate from the driving means or the driving means so that the bending medium node can be fed at a feed speed slightly larger than a feed speed of the bending medium node by the main drive shaft. Auxiliary drive with driving force applied by A main drive means for absorbing an excessive driving force acting on the auxiliary drive shaft based on a difference between respective feed speeds of the shaft and the auxiliary drive shaft and the main drive shaft of the bending mediator. Alternatively, a wrapping transmission device comprising: a buffering means provided between the auxiliary driving means and the auxiliary driving shaft. 2. The bending bending node is a roller chain made of stainless steel or resin, and the roller chain is
The winding transmission according to claim 1, wherein the transmission is wound around a sprocket wheel attached to each of the drive shaft and the driven shaft so as to rotate integrally with the shaft.