JPH10331933A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the assembly by providing a roller connected with a rotary shaft for rotation and an output mechanism provided with an output shaft connected in a part other than a connection part, making the output shaft eccentric centered on the rotary shaft, and fixing a position of the output mechanism. SOLUTION: When a rotary shaft 56 rotates in the arrow direction, a roller 61c begins to rotate, is brought into pressure-contact with a rotary cylinder 62 and the rotary shaft 56, and moves in such a manner that it is nipped in a wedge angle M. Consequently, rollers 61a, 61b come into pressure-contact with the rotary shaft 56 to start their revolutions centered on pins 60a, 60b. The rotary cylinder 62 in contact with outer peripheries of three rollers 61 begins to rotate in the arrow direction due to friction force and is connected when rotation speed of the rotary shaft 56 is higher than that of an output shaft. When the rotary cylinder 62 rotates at a higher speed than that of the rotary shaft 56, the roller 61c starts to move in the direction in which pressure-contact of the rotary shaft 56 and the rotary cylinder 62 is shut off because there is no pin which becomes a central shaft in the roller 61c and operates so as to shut off the power transmission. Consequently, simple adjustment is possible by eccentrically centering a position of the output shaft on the rotary shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device for transmitting a driving force from an electric motor or the like.

[0002]

2. Description of the Related Art Conventionally, a power transmission device of this type is provided with a pulley on an output shaft of an electric motor as described in Japanese Patent Application Laid-Open No. 9-58568 (B62M23 / 02). Thus, power is transmitted to a final-stage pulley integrally connected to the rotation-side casing. In addition, a tension pulley is provided at an intermediate portion of the belt in order to adjust the tension of the belt, and the belt is pressed by the tension pulley to reduce loss in power transmission.

However, with such a configuration, even if the entire casing is to be made compact, the tension pulley is not small because of the presence of the tension pulley, and a tension pulley must be mounted in addition to the mounting of the reduction gear. As a result, there is a problem that assembling takes time and costs are high.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has as its object to provide a compact and easy-to-assemble power transmission device capable of stretching a belt without using a tension pulley. Make it an issue.

[0005]

SUMMARY OF THE INVENTION The present invention comprises a roller which is connected to a rotating shaft and rotates, and an output mechanism having an output shaft which is connected at a portion other than a portion of the roller connected to the rotating shaft, wherein the output mechanism comprises: The shaft is eccentric about the rotation axis, and is provided with a fixing member for fixing the position of the output mechanism.

The roller is disposed in contact with a rotating shaft by a plurality of columnar rollers, and the output mechanism comprises:
The roller is characterized in that it is formed in a cylindrical shape, and the outer peripheral surface of the roller is arranged in contact with the inner surface.

[0007] At least one of the plurality of rollers has an outer diameter different from that of the other rollers.

Further, the output shaft is provided with a pulley for providing an annular transmission member.

The output mechanism comprises a rotary cylinder connected to the roller, and a lid which covers the rotary cylinder and is fixed by a fixing member.

In the configuration of the present invention, when assembling, in order to connect a roller to a rotating shaft as a driving source and adjust the connection between the output shaft and a member connected to the output shaft,
The output mechanism is eccentric about the rotation axis of the input mechanism, and the output mechanism is fixed by the fixing member at a position where the connecting member between the output shaft and the output shaft appropriately meshes while changing the position of the output shaft. When the member connected to the output shaft is a belt, a chain, or the like, the output mechanism is rotated around the input shaft and is fixed by a fixing member when it is appropriately pulled. Will work.

The output mechanism is also decelerated by a plurality of rotating bodies to rotate the output shaft, so that it also functions as a speed reducer.

Since at least one of the outer diameters of the plurality of rollers is different from the others, the positions of the rotation shaft and the output shaft can be set to eccentric positions, and the position of the output shaft can be easily adjusted. Can be eccentric.

Further, in order to transmit power, an annular transmission member such as a chain or a belt is provided on a pulley provided on the output shaft, and this power transmission device can serve as a tension pulley.

The output mechanism can fix the position of the output shaft by moving the lid and fixing it with the fixing member.
The rotation of the roller is transmitted to a rotating cylinder in the lid body to rotate the output shaft. Since the rotary cylinder for transmitting power is covered with the lid, the lid does not rotate, which is very safe, and the position of the output shaft can be easily fixed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to an example of a drive unit of an electrically assisted bicycle with auxiliary power.

First, the configuration of the entire electric assist bicycle will be described with reference to FIG.

1 is a head pipe 2 provided at the front part,
The main frame is connected to a seat tube 4 provided below the saddle 3, and a pedal 5 which can be rotated by human power is attached to a portion where the main frame 1 and the seat tube 4 are connected.

Reference numeral 6 denotes a front wheel which is linked with the movement of the steering wheel 7 and determines the traveling direction by operating the steering wheel 7. The front wheel 6 is comprised of a spoke 8, a rim 9, and a tire 10.

Reference numeral 11 denotes a rear wheel serving as a driving wheel.
The vehicle also includes a tire 12, a rim 13, spokes 14, and a drive unit 15 for driving the rear wheel 11.

Reference numeral 16 denotes a front sprocket which rotates with the rotation of the pedal 5. The front sprocket 16 includes a chain.
17 is engaged and the rotation of the front sprocket 16 is
Power is transmitted to a rear sprocket 36 described later provided on the 15 axle 18.

Reference numeral 19 denotes a battery serving as a power supply for the electric motor 55 described later, which contains a 24-volt NiCd battery.
Also, the battery 19 is removable and can be charged indoors when charging. Reference numeral 20 denotes a mounting table which is mounted so as to surround the main frame 1 and on which the battery 19 is mounted.

Reference numeral 21 denotes a front basket, and reference numeral 22 denotes a stand for supporting a bicycle during parking.

FIG. 4 shows a specific configuration of the driving unit 15 described above.

Numeral 30 is a resin-made disc-shaped fixed casing fixedly attached to the main frame 1 and 31 is
A rotating casing that is coaxial with the fixed casing 30 and rotates outside the fixed casing 30. The fixed casing 30 and the rotating casing 31 together form a hub. A frame 33 having two annular ribs 32 is provided on the outer periphery of the rotating side casing 31. A plurality of spokes are provided from the annular rib 32 of the frame 33 to the rim 13 on which the tire 12 is mounted. 14 are stretched. Further, the fixed casing 30 is formed by opening only a portion of the rear sprocket 36, which will be described later, so as to surround the outer periphery of the rear sprocket 36 in a side view.
Is provided.

Reference numeral 34 denotes a hub-internal transmission provided on the axle 35. The transmission 34 is joined to the rear sprocket 36 via a ratchet (not shown). That is, the human force from the chain 17 is applied only in one direction by the ratchet, and when a force is applied in the reverse rotation direction, the driving force is cut off.

Reference numeral 37 denotes two bearings fitted on the outer periphery of the transmission 34. The bearing 37 has a cylindrical container 38 inserted into the outer periphery of the transmission 34 at a predetermined interval. . In order to hold the position of one side of the bearing 37, a cylindrical second container 39 is fitted and provided.

Numeral 40 is a flange formed of metal and formed continuously from the cylindrical end face in a circumferential direction. The cylindrical portion of the flange 40 which is in contact with the transmission 34 is provided on one side of the transmission 34. The screw is cut off so as to be screwed into the formed bolt 41.

Reference numeral 42 denotes an extension flange which is fixed to the flange 40 by bolts 41 and forms a circumferential portion further inside the flange 40. The extension flange 42 is Is abutted against the second container 39 by being tightened with a screw, and is held at a height interval between one side of the bearing 37 and the second container 39. Further, the extension collar 42 rotates with the rotation of the outer periphery of the transmission 34. One end of a ring-shaped washer spring 43 having spring properties is held by a pin 44 on a part of the extension flange portion 42, and the other end of the washer spring 43 is fixed to the rotating side casing 31 in the final stage. It is held on a pulley 72 by a pin 45. Further, a pin 44 holding one end of the washer spring 43 is formed with a cylindrical extension 46, and furthermore, an inclined portion 47 is formed on the chain 17 side of the final stage pulley 72. .

Reference numeral 48 denotes a bearing provided on the container 38.
37 is a cylindrical outer container fixedly provided between the outer periphery and the last stage pulley 72, and the outer container 48 rotates with the rotation of the last stage pulley 72. Further, the outer container 48 rotates in the same direction as the container 38 by a deflection due to the bending by the washer spring 43.

Reference numeral 49 denotes a sliding member provided on the outer periphery of the outer container 48 so as to be slidable in the axle 35 direction.
A projection 50 is formed on the side of the final stage pulley 72 so as to protrude and abuts on the inclined portion 47, and a concave portion 50 is formed on the extension 46 to be fitted. Further, the sliding member 49 is provided with an aluminum ring 51 formed of a conductive member, and the convex portion 50 comes into contact with the inclined portion 47, and the inclined portion 47 slides by moving in the rotational direction. The member 49 slides helically, and the ring 51 moves in the axle 35 direction.
The sliding member 49 is provided with a spring 52, which is constantly urged to the right as shown in FIG. The other end of the spring 52 is held by a stopper 53 provided on the outer container 48.

Numeral 54 denotes a coil provided near the ring 51 of the fixed casing 30 where the ring 51 slides.
Can convert a change in inductance due to the movement of the ring 51 into an electric signal. That is, the manual driving torque of the manual driving force can be converted into an electric signal.

Reference numeral 55 denotes an electric motor provided as an auxiliary power for the vehicle provided in the fixed casing 30. The electric motor 55 is driven based on an output signal from a control board 82 described later, and includes a rotor 57 having a rotating shaft 56; And a stator 58 provided therearound.

Reference numeral 59 denotes a planetary roller reduction mechanism connected to the rotating shaft 56 for reducing the rotation of the motor 55. The planetary roller reduction mechanism 59 is provided rotatably about a pin 60 protruding and fixed from the motor 55. A plurality of rollers 61 connected to a rotating shaft 56 of the electric motor 55 and rotated by the rotation of the rotating shaft 56; a rotating cylinder 62 connected to the outer periphery of the plurality of rollers 61 and rotated by the rotation of the roller 61; The output shaft 63 is formed integrally with the cylinder 62 so as to protrude therefrom. 64 is the output shaft 63
And a lid of a planetary roller reduction mechanism 59 fixed to the electric motor 55 via the bearing 65. Here, the rotation shaft 56 of the electric motor 55 and the output shaft 63 of the planetary roller reduction mechanism 59 are disposed at eccentric positions. The rotary cylinder 62 and the lid 64 are collectively called an output mechanism, and the driving force is actually transmitted by the rotary cylinder 62.

Reference numeral 66 denotes a pulley fixed to the output shaft 63 of the planetary roller reduction mechanism 59. The pulley 66 has a belt 67 extending over the last-stage pulley 72, and the driving force from the electric motor 55 Is transmitted.

The planetary roller reduction mechanism 59 and the pulley
The configuration of the rotating shaft 56 of the electric motor 55 will be described later with reference to FIG.

Reference numeral 68 denotes a band brake which is provided so as to cover a part of the outer wall of the rotating casing 31 and which brakes the rotation of the rotating casing 31.
When the brake shoe 69 is operated by a brake lever 69 provided on the handlebar 7, the wire 70 is pulled to move the brake shoe 71 inward, and the brake shoe 71 and the rotating casing 31 come into contact with each other, so that the rotating casing 31, The rear wheel 11 can be braked.

Next, the appearance of the driving unit 15 will be described with reference to FIG.
A description will be given based on FIG.

Reference numeral 80 denotes a resin cover for covering the motor 55, which is press-fitted into the fixed casing 30.

A metal hub plate 81 is provided inside the fixed casing 30 and is formed in a Y-shape so as to hold the electric motor 55 from below, and is attached to the axle 35. 81 is the fixed side casing 30
The central open part protrudes outward and is attached.
The hub plate 81 is provided with an opening 84 through which the chain 17 faces, together with the fixed casing 30. Further, the fixed side casing 30 can be divided, the chain 17 can be detached and the chain 17 can be replaced by dividing and removing, and also in order to improve workability at the time of assembly. It is provided.

Reference numeral 82 denotes a control board for driving the electric motor 55 provided in the rotating casing 31. As shown in FIG. 6, the control board is housed in a frame 83 made of resin.

Next, a torque detecting section for detecting a manual driving force applied to the pedal 5 will be described in detail with reference to FIG.

The manual driving force applied when the pedal 5 is depressed is input to the rear sprocket 36 via the chain 17 and
After being shifted by the transmission 34, the washer spring 43 bends. The magnitude of the deflection indicates the magnitude of the manual driving force. The degree of bending of the washer spring 43 is such that the final-stage pulley 72 is rotated with a delay corresponding to the bending. That is, there is a gap between the container 38 and the final stage pulley 72 to rotate. When the washer spring 43 bends, the inclined portion 47 moves from the position indicated by the solid line to the position indicated by the two-dot chain line. At this time, since the convex portion 50 formed on the sliding member 49 is in contact with the inclined portion 47, the convex portion 50 moves toward the axle 35 by the movement of the inclined portion 47. The sliding member 49 is moved by a spring.
It moves spirally from the solid line to the position indicated by the two-dot chain line against the biasing force of 52. As a result, the movement of the ring 51 also moves from the position indicated by the solid line to the position indicated by the two-dot chain line, whereby the inductance of the coil 54 can be changed. That is, the magnitude of the manual driving force can be converted into an electric signal. Further, when the manual driving force is lost, the washer spring 43 returns to the original position due to the restoring force of the spring, so that the inclined portion 47 returns to the original position, and the convex portion 50 abutting on the inclined portion 47 restores the spring 52. Return by force. As a result, it is possible to change the inductance of the coil 54 and detect a state in which no manual driving force is applied, based on the change in the inductance of the coil 54. These inclined portion 47, sliding member 49, ring 51,
A combination of the coil 54 and the like is referred to as a torque detecting unit 88. Further, in order for the sliding member 49 to move smoothly in the axle 35 direction, a concave portion 50 fitted to the extension 46 of the pin 44 is provided with a sliding member.
It is formed in 49.

Next, the configuration of the rollers of the planetary roller reduction mechanism 59 will be described with reference to FIG.

The roller 61 of the planetary roller reduction mechanism 59 is
Three rollers 61 are provided in pressure contact with the outer periphery of the rotating shaft 56 of the electric motor 55 and the inner periphery of the rotating cylinder 62, and the roller 61a having the largest diameter that rotates around the pin 60a and the
The roller 61b rotates about the center b and the roller 61c has the same diameter as the roller 61b and has no pin. Since the position of the roller 61c is not fixed by the pin, the roller 61c can move in a space surrounded by the roller 61a, the rotating shaft 56, and the rotating cylinder 62. The roller 61c has a position where the roller 61c comes into pressure contact with the rotating shaft 56 and the rotating cylinder 62 at a wedge angle M, and the position of the roller 61c shown in FIG.

In the planetary roller reduction mechanism 59, since the size of the roller 61 is different as described above, the rotation shaft 56,
That is, the input center of the planetary roller reduction mechanism 59 and the output shaft 63 of the planetary roller reduction mechanism 59 are configured to be eccentric. In FIG. 1, the center of the output shaft 63 is located at the position where the dashed line intersects. As described above, the planetary roller speed reduction mechanism 59 controls the rotation of the rotation shaft
When the rotation speed is higher than the rotation speed of the output shaft 63, the roller 61c moves in the direction in which the roller 61c presses between the rotation shaft 56 and the rotation cylinder 62 to transmit the power of the rotation shaft 56 to the output shaft 63. When the rotation is faster than the rotation speed of the rotation shaft 56, the roller 61c
By moving in the direction of breaking the pressure contact with the other rollers 61a,
The pressure contact between the rotary shaft 56 and the rotary shaft 61b disappears, and the transmission of power from the rotary shaft 56 is interrupted. That is, the roller 61c has a function of a clutch for interrupting the transmission of power by the moving operation of the roller 61c, and the roller 61c corresponds to a clutch means.

Next, the operation will be described.

When the rotation shaft 56 rotates in the direction of the arrow, the roller 61c starts rotating by this rotation, and at the same time, presses against the rotation cylinder 62 and the rotation shaft 56 and moves so as to be sandwiched by the wedge angle M. . As a result, the other two rollers 61a and 61b also come into pressure contact with the rotating shaft 56 and the pins 60a and 60b
Start rotating around b. Then, when the three rollers 61 are pressed against the rotating shaft 56, the rotating cylinder 62 in contact with the outer periphery of the roller 61 starts rotating in the direction of the arrow due to the frictional force with the roller 61. This state continues when the rotation speed of the rotation shaft 56 is higher than the rotation speed of the output shaft 63.

Next, a case where the rotation speed of the rear wheel 11 becomes faster than the rotation speed of the motor 55 will be described. When the roller 61c is pressed against the motor 55 as shown in FIG. If the rotation speed becomes faster than
Rotates faster than the rotating shaft 56, and the roller 61c has no pin serving as a central axis.
Start to move in the direction to break the pressure contact with. And the rotation axis 56
When there is no pressure contact between the roller 61c and the other roller 61a,
Since the pressure contact of the rotary shaft 56 with the rotary shaft 56 is also lost, the power from the electric motor 55 cannot be transmitted to the rotary cylinder 62.
The movement of 61c operates to cut off the transmission of power. That is, the roller 61c functions as a one-way clutch. Thus, when the rear wheel 11 rotates faster than the motor 55, the motor 55 does not load the rotation of the rear wheel 11, and the vehicle can run smoothly.

Next, the planetary roller reduction mechanism 59, the electric motor 55,
The configuration of the pulley 66 will be described in detail with reference to FIG.

Reference numeral 89 denotes a bearing provided on the planetary roller reduction mechanism 59 for fitting the rotating shaft 56 of the electric motor 55. The rotating shaft 56 is fitted to the bearing 89 to make the rotating shaft 56 planetary. It can be fixed and rotated on the roller reduction mechanism 59 and can be smoothly rotated. In this embodiment, the bearing is used as an input mechanism for inputting the rotation shaft 56, but the rotation shaft 56 and the planetary roller reduction mechanism are used.
Anything can be used as long as it connects 59.

Reference numeral 90 denotes a lid 64 of the planetary roller reduction mechanism 59.
The fixing member 90 is provided at two places on the outer circumference of the fixing member 90.
Is composed of a stopper plate 91 pressed from above by the lid 64, and a screw 92 penetrating through the stopper plate 91 and screwing into the housing of the electric motor 55. The fixing member 90 prevents the lid 64 from rotating.

The operation of the above configuration will be described with reference to FIGS.

When the planetary roller reduction mechanism 59 is mounted, the rotating shaft 56 is fitted to the bearing 89. Before the cover 64 is fixed by the fixing member 90, the belt is
Attach 67. At this time, since the rotating shaft 56 of the electric motor 55 and the output shaft 63 provided on the lid 64 are eccentric, the lid 64 is moved while being eccentric about the rotating shaft 56 of the electric motor 55, and the belt Fixing member at the position where 67 is pulled most
Secure with 90. This state is shown by the movement from the two-dot chain line state shown in FIG. 3 to the solid line position. When the lid 64 is at the solid line position, it is fixed by the fixing member 90. In this fixing method, the cover 64 is fixed by tightening the screw 92 penetrating the stopper plate 91, and the belt 67 can be stretched without requiring a member such as a tension pulley.

Next, the operation of the above configuration will be described with reference to FIG.

First, the human-powered driving system will be described. The human power provided by the pedal 5 is transmitted to the rear sprocket 36 by the chain 17 and is shifted by the transmission 34. Then, the washer spring 43 is bent to pull the final stage pulley. The rotation is transmitted to 72 and the rotation side casing 31 is rotated and driven.

Next, the electric drive system will be described. The deflection of the washer spring 43 described above is detected by the torque detecting section 88 as the magnitude of the manual drive force, and the signal is detected to generate a human drive signal as a control board signal. Enter in 82. Then, a driving signal of the electric motor 55 is output so that the electric driving force becomes a magnitude corresponding to the input signal of the manual driving force, and the electric motor 55 is driven. The driving force output from the electric motor 55 is transmitted to the final stage pulley 72 via the planetary roller reduction mechanism 59, the pulley 66, and the belt 67, and drives the rear wheel 11 together with the manual driving force.

In this embodiment, the belt 67 is provided on the pulley 72 to transmit power.
A gear may be provided to adjust the meshing between the gears.

As described above, the rotary cylinder 62 having the bearing 89 for inputting the rotary shaft 56 of the electric motor 55, the roller 61 connected to the rotary shaft 56 for rotation, and the output shaft 63 connected to the roller 61.
The output shaft 63 is eccentric about the rotating shaft 56 of the electric motor 55, and the fixing member 90 for fixing the position of the rotating cylinder 62 is provided, so that the member such as the belt 67 transmitted from the output shaft 63 is provided. Can be adjusted, that is, the belt 67 can be fixed in an appropriately stretched state, so that a transmission mechanism with less mechanical loss can be provided, and power can be transmitted efficiently.

The roller 61 is arranged in contact with the rotating shaft 56 by a plurality of cylindrical rollers 61, and the rotating cylinder 62 is formed in a cylindrical shape and the outer peripheral surface of the roller 61 is arranged in contact with the inner surface. Therefore, a compact speed reduction mechanism can be provided.

Further, among the plurality of rollers 61, the roller 61
Since the outer diameter of a is larger than the outer diameters of the other rollers 61b and 61c, the rotation shaft 56 and the output shaft 63 can be configured to be eccentric, and the tension of the transmission mechanism such as the belt 67 can be adjusted. I can do it.

Since the output shaft 63 is provided with the pulley 72 for providing the annular belt 67, sufficient deceleration can be performed with a compact configuration.

Further, the output mechanism includes a rotating cylinder 62 and a fixed member 90.
Since the lid 64 has a lid 64, the position of the output shaft 63 can be determined by a simple operation of fixing the lid 64 with a fixing member, and since the rotating cylinder 62 is covered with the lid 64, Is also safe.

[0063]

According to the present invention, there is provided a roller which is connected to a rotating shaft and rotates, and an output mechanism having an output shaft which is connected at a portion other than a portion where the roller is connected to the rotating shaft. Equipped with a fixing member that can be eccentric to the center and fixes the position of the output mechanism, it is possible to adjust the position of the output shaft by eccentricity about the rotation shaft, and adjust the position with the transmission member provided on the output shaft Therefore, a transmission mechanism with less mechanical loss can be provided, and power can be transmitted efficiently. In addition, workability is improved because the position can be easily adjusted.

Further, the roller is arranged in contact with the rotating shaft by a plurality of columnar rollers, and the output mechanism is formed in a columnar shape and the outer peripheral surface of the roller is arranged in contact with the inner side surface. A compact speed reduction mechanism can be provided.

Since the outer diameter of at least one of the plurality of rollers is different from the outer diameter of the other rollers, the positions of the output shaft and the rotation shaft can be eccentric, and the output shaft and the output shaft can be eccentric. The members to be connected can be easily adjusted.

Further, since the output shaft is provided with a pulley for providing an annular transmission member, sufficient deceleration can be performed with a compact configuration.

The output mechanism is composed of a rotating cylinder connected to the roller and a lid that covers the rotating cylinder and is fixed by a fixing member. Therefore, the output shaft can be easily fixed by fixing the lid with the fixing member. In addition to being able to determine the position, the rotating cylinder is covered with a lid, so it is safe during work.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a planetary roller speed reduction mechanism showing an embodiment of the present invention.

FIG. 2 is a plan view of the fixed side casing.

FIG. 3 is a side view of the planetary roller speed reduction mechanism.

FIG. 4 is a side sectional view of the driving unit.

FIG. 5 is a side sectional view of the torque detector.

FIG. 6 is a plan view of the fixed side casing as viewed from the inside.

FIG. 7 is a plan view of the stationary casing as viewed from outside.

FIG. 8 is a side view showing the entire configuration.

FIG. 9 is the same power system diagram.

[Explanation of symbols]

 56 Rotary shaft 61 Roller 63 Output shaft 62 Output mechanism (rotary cylinder) 64 Output mechanism (lid) 90 Fixing member 67 Transmission member (belt)

Claims (5)

[Claims] An output mechanism having an output shaft connected at a portion other than a portion where the roller is connected to the rotation shaft, wherein the output shaft has a center with respect to the rotation shaft. A power transmission device, further comprising a fixing member which can be eccentric to the output mechanism and fixes the position of the output mechanism. 2. The apparatus according to claim 1, wherein the roller is a plurality of columnar rollers arranged in contact with a rotating shaft, and the output mechanism is formed in a columnar shape and an outer peripheral surface of the roller is arranged in contact with an inner surface of the roller. The power transmission device according to claim 1, wherein: 3. The power transmission device according to claim 2, wherein an outer diameter of at least one of the plurality of rollers is different from an outer diameter of the other roller. 4. The power transmission device according to claim 1, wherein a pulley for providing an annular transmission member is provided on the output shaft. 5. The power transmission device according to claim 1, wherein the output mechanism includes a rotary cylinder connected to the roller, and a lid that covers the rotary cylinder and is fixed by the fixing member.