JPH1081292A - Drive unit of bicycle with auxiliary power - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the extent of vibration and noise in a reduction gear part on the motor side without adopting any expansive planetary roller type reduction gear by setting up both axes of an auxiliary power motor and a crankshaft almost parallelly, and converting a first stage geared transmission device of the motor into a belt transmission device. SOLUTION: An auxiliary power motor 15 sets up an axis of its driving shaft 15a in parallel with that of a crankshaft 5, and a geared transmission shaft 32, etc., are installed each in space between this shaft 15a and the crankshaft 5 in parallel with this crankshaft 5. In addition, a small diametral timing belt pulley 38 is attached tight to the shaft 15a of the motor 15, while a large diametral timing belt pulley 40 is installed in the shaft 32 via a one-way clutch 39, and a timing belt 41 is laid across these pulleys 38 and 40. Both these axes of the auxiliary driving motor and the crankshaft are almost parallely set up, and further a geared transmission device at the first stage of the motor is converted into a belt transmission device, so that there is less in noise occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for a bicycle with an auxiliary power provided with a power transmission device driven manually by a pedal and an auxiliary power device by a motor.

[0002]

2. Description of the Related Art A conventional bicycle with an auxiliary power is disclosed, for example, in Japanese Patent Application Laid-Open No. 5-58379. The assisted bicycle includes a human-powered drive system for steering by human power and an electric drive system using a motor as a power source, and travels together with human power, that is, the stepping force of the occupant, and the driving force of the motor. Was configured to be able to. In addition, a planetary gear type speed reducer is interposed in a power transmission path from the motor to the output shaft of the manual drive system.

A bicycle with auxiliary power disclosed in Japanese Patent Application Laid-Open No. 7-95744 has a human-powered drive system, an electric drive system provided in parallel with the human-powered drive system, and a drive force change caused by human power. A control device for controlling the output of the electric drive system, and a mechanism for transmitting the power of the motor serving as the power source of the electric drive system to the output shaft of the human-powered drive system by reducing the rotation of the motor by a planetary roller type speed reducer. Things.

[0004]

SUMMARY OF THE INVENTION The above-mentioned JP-A-5-5-5
In the bicycle with auxiliary power disclosed in Japanese Patent No. 8379,
When the vehicle travels using the power of a motor, there is a problem in that vibration and noise increase in the reduction gear portion on the motor side.
In order to solve the above-mentioned problem, Japanese Patent Application Laid-Open No. 7-957
No. 44, it is possible to suppress vibration and noise by employing the planetary roller type speed reducer. However, this planetary roller type speed reducer is required to have high dimensional accuracy and is expensive. There was a problem that lubrication management was required.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a bicycle equipped with a power transmission auxiliary power device together with a power transmission device driven by human power and a shaft of an auxiliary power motor and a crankshaft. Are arranged substantially in parallel with each other, and a driving device for a bicycle with auxiliary power is constituted by using the first-stage deceleration transmission mechanism of the motor as a belt transmission mechanism.

In the present invention, a drive disk is provided on a crankshaft of a bicycle via a one-way clutch, and a driven gear integrated with a front gear is rotatably provided on the crankshaft, and the driven gear and the drive disk are provided. A rotational phase difference is generated between the drive disk and the driven gear with a change in the transmission torque between the drive disk and the driven gear, and a torque detecting member that moves in the axial direction of the crankshaft by the rotational phase difference is provided. A displacement sensor for detecting the displacement of the detection member is provided, and a motor for auxiliary power is driven via a control circuit that inputs an output signal of the displacement sensor.A shaft of the motor is provided in parallel with the crankshaft, This motor transmits auxiliary power to the driven gear via a reduction mechanism, and the first-stage reduction transmission mechanism of the reduction mechanism is provided with auxiliary power as a toothed belt transmission mechanism. Make up the bicycle of the drive unit.

In the driving device for a bicycle with an auxiliary power according to the present invention, the axis of the auxiliary power motor and the axis of the crankshaft are arranged substantially in parallel, and a belt transmission is used for the first-stage reduction portion of the motor. For this reason, even if vibration peculiar to the motor occurs, quiet power transmission is possible. In addition, the initial tension of the belt absorbs the backlash of the gear transmission, and the elasticity of the belt reduces the shock at the time of starting the motor due to the backlash. Further, since the belt pulley can be made lighter with a light alloy or the like, the load on the motor for auxiliary power can be reduced.

[0008] In a preferred embodiment of the present invention,
The position of the displacement sensor of the device described above may be adjusted by an adjusting screw. This facilitates adjustment of the mounting position of the torque detecting member in the direction of the crankshaft, and can absorb variations in the accuracy of each component, thereby reducing manufacturing costs.

Further, in a preferred embodiment of the present invention, the motor output may be transmitted to a small-diameter drive sprocket provided below the front gear to provide an auxiliary power from the side where the chain is loose.

In a preferred embodiment of the present invention, a planetary gear mechanism fixed coaxially with the crankshaft is provided, and a reaction torque of the planetary gear mechanism with respect to the input torque of the crankshaft is detected by a sensor. The auxiliary power motor may be driven based on a signal from the controller.

Further, in the present driving device, since the motor output is transmitted to the small-diameter driving sprocket provided below and below the front gear, the number of reduction stages can be reduced. Further, by transmitting the motor output to a small-diameter drive sprocket provided below and behind the front gear, auxiliary power is provided on the loose side of the chain, so that a sufficient chain winding angle can be obtained.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall side view of an assisted powered bicycle provided with a driving device according to a first embodiment of the present invention, and FIG. 2 shows a transmission system of a hanger portion of the assisted powered bicycle shown in FIG. FIG. 3 is an elevational view showing a state in which a side cover of a case is removed from a back surface, and FIG. 3 is an ABC of FIG.
FIG. 4 is a plan view showing a cross section taken along a cutting line of FIG.
FIG. 5 is a plan view showing a cross section taken along the line AB-F-D-E of FIG. 2, and FIG. 5 is an exploded perspective view of each member on the crankshaft.

In the figures, 1 (see FIG. 1) is a front wheel of a bicycle, 2 is a rear wheel, 3 is a vehicle body (frame), 4 (see FIGS. 1 to 4) is a case of a driving device provided on a hanger, and 4a is a case. The main body, 4b and 4c are side covers, 4d (see FIG. 2) is a bottom case, and 5 is a case 4, bearings 6, 7, and 8 (FIGS. 3 and 4).
Reference numeral 9) denotes a crank arm, and 10 denotes a pedal.

Reference numeral 11 denotes a front gear (front sprocket) rotatably provided on the crankshaft 5 via a bearing 7;
2 is a rear gear (rear sprocket) provided on the rear axle 13,
Reference numeral 14 denotes a chain extending over the front gear 11 and the rear gear 12. Reference numeral 15 denotes a motor for electric auxiliary power, reference numeral 16 denotes a battery serving as a power source thereof, and reference numeral 17 (see FIGS. 1 and 2) denotes a control circuit (controller) for controlling the power of the battery 16 and sending it to the motor 15. .

In this embodiment, as shown in FIGS. 3 to 5, a boss portion 18a, a disk portion 18b, and a disk portion 18b are provided.
A driving disk 18 comprising a plurality (three in this embodiment) of projections 18c is provided on the outer periphery of a one-way clutch (ratchet mechanism) 19 and bearings 20, 20 in the middle of the crankshaft 5.
Is provided so as to transmit only the rotation of the crankshaft 5 in the forward direction via the.

A driven gear 21 in which the front gear 11 and the boss 21a are fitted and fixed to each other and integrally connected is rotatably provided on the crankshaft 5 via the bearings 6 and 7.
A rotational phase difference is generated between the driving disk 18 and the driven gear 21 in accordance with a change in the transmission torque between the driving disk 1 and the driving disk 18.

That is, as shown in FIGS. 3 to 5, a substantially U-shaped spring plate 22 (two in this embodiment) is inserted between the driving disk 18 and the driven gear 21. One end of the spring plate 22 is connected to the driving disk 18 by a hole 22a and a pin 23 (a pin indicated by a dotted line in FIGS. 3 and 4), and the other end of the spring plate 22 is driven by a hole 22b and a pin 24. Connected to gear 21.

With the above construction, when torque is transmitted from the driving disk 18 to the driven gear 21, the U-shaped spring plate 22 changes with the magnitude of the torque.
Causes a difference in the rotational phase difference between the driving disk 18 and the driven gear 21.

Further, the driven gear 21 is
The crankshaft 5 on the opposite side is fitted with the boss 25a, and a plurality of circumferential portions (3 in this embodiment) of the large diameter portion 25c formed integrally with the boss 25a via the conical portion 25b. ) Is provided with a protruding piece 25e having a tip formed on a slope 25d, and an inner peripheral surface of the large-diameter portion 25c is slidable in the axial direction with a projection 18c provided on the outer periphery of the driving disk 18 described above. By providing a sliding engagement piece 25f (see FIGS. 3 and 4) for engagement,
A torque detecting cone 25 as a torque detecting member is integrally formed.

On the side surface of the driven gear 21 on the side of the torque detecting cone 25, a projecting piece 2 of the torque detecting cone 25 is provided.
Engaging pieces 21b are protrudingly provided at positions that abut against the inclined surface 25d at the tip of 5e. The torque detecting cone 25 fitted to the crankshaft 5 is constantly pressed against the driven gear 21 by the coil spring 26. ing. 27 is a stop ring for the coil spring 26.

A guide fitting 28 (see FIGS. 3 and 4) is attached to the side cover 4c of the case 4. A displacement sensor 29 is slidable in the axial direction of the crankshaft 5 with respect to the guide fitting 28. The contact 29 a of the displacement sensor 29 abuts against the wall surface 25 g of the torque detecting cone 25. Reference numeral 30 denotes a return spring fitted to the shaft cylinder 29b of the displacement sensor 29, and reference numeral 31 denotes an adjusting screw screwed to the side cover 4c. The position of the displacement sensor 29 can be adjusted by the adjusting screw 31.

The above-mentioned auxiliary power motor 15 is
The axis of the drive shaft 15a is arranged parallel to the axis of the crankshaft 5, and between the shaft 15a and the crankshaft 5, shafts 32 and 33 for deceleration transmission are provided in parallel with the crankshaft 5, respectively. 34, 35 (see FIG. 3) are bearings 36, 3 of the shaft 32.
Reference numeral 7 (see FIG. 4) denotes a bearing for the shaft 33.

A small-diameter timing belt pulley 38 is fixed to the shaft 15a of the motor 15, and a large-diameter timing belt pulley 40 is provided on the shaft 32 via a one-way clutch 39. Hang the timing belt 41 over. The small gear 4 is integrally formed with the shaft 32.
2 (see FIG. 3), a large gear 43 (see FIG. 4) meshing with the small gear 42 is fixed to the shaft 33, and a small gear 44 meshing with the driven gear 21 is fixed to the shaft 33. Provide.

Next, the operation of the bicycle with the auxiliary power configured as described above will be described. Pedal 1 for crank arm 9
When the crankshaft 5 rotates by stepping on the zero, the rotation is transmitted to the driving disk 18 via the one-way clutch 19, and further, two spring plates 22, pins 23 and 24, and a driven gear 21 are transmitted from the driving disk 18. The rotation is transmitted to the front gear 11 via. When the front gear 11 rotates, the rear gear 12 rotates via the chain 14, so that the rear wheel 2 rotates and the bicycle runs. In this case, the driven gear 2
1 rotates, the gears 44, 43, 42 meshing therewith
The shaft 32 also rotates, but the rotation of the shaft 32 is not transmitted to the pulley 40 by the action of the one-way clutch 39.

When the torque applied to the crankshaft 5 increases while the bicycle is running, the two U-shaped spring plates 22 between the driving disk 18 and the driven gear 21 bend and the driving disk 18 and the driven disk 18 are driven. A rotation phase difference is generated between the driven gear 21 and the engagement piece 21b of the driven gear 21 so that the torque detection cone 2
As a result, the torque detection cone 25
Move downward in FIGS. 3 and 4 and press the contact 29a of the displacement sensor 29, whereby the displacement sensor 29 outputs a signal and drives the motor 15 via the control circuit 17 which is a controller. When the motor 15 rotates, the pulley 38, the timing belt 41 as a toothed belt, the pulley 40, the one-way clutch 39, the shaft 32, the gear 42,
The front gear 11 is auxiliary-driven by the motor 15 via the shaft 43, the shaft 33, and the gears 44 and 21.

FIG. 6 is an overall side view of a bicycle with auxiliary power provided with a driving device according to a second embodiment of the present invention.
FIG. 7 is a view showing a state where the cover of the case is removed from the driving device for the bicycle shown in FIG. 6. FIG. 8 shows ABC of FIG.
FIG. 9 is a cross-sectional view taken along the line -DE, and FIG.
It is sectional drawing along the line of BCCE.

FIGS. 7 to 9 are views showing a driving device according to the second embodiment of the present invention. As shown in FIG. 7, in the driving device according to the present embodiment, the rotation of the pulley 47 fixed to the shaft of the motor 15 and the pulley 48 are transmitted by the timing belt 49 to perform the first-stage deceleration.

As shown in FIG. 9, the pulley 48 and the gear 50 are arranged coaxially via a one-way clutch 55. The power from the motor 15 is transmitted to the gear 50 by the one-way clutch 55, but when the rotation speed of the gear 50 is higher than the transmission rotation speed of the motor 15,
The one-way clutch 55 becomes free. The motor 15
When the vehicle is stopped, the rotation caused by the driver's pedaling operation or the like is not transmitted to the motor 15, so that the pedaling operation does not become heavy.

As shown in FIGS. 7 to 9, the gear 50 and the gear 5
1 performs the second-stage reduction, and the gear 52 coaxially integrated with the gear 51 meshes with the gear 53 to perform the third-stage reduction. The gear 53 is coaxially integrated with the driving sprocket 45, and the output of the motor 15 is reduced to three stages and transmitted to the driving sprocket 45.

The drive sprocket 45 is wound around the loose side of the chain 14 as shown in FIG. 6, and provides auxiliary power to the rear wheel 2 by chain transmission. The vehicle speed is detected by a speed sensor 54 disposed near the gear 53.
This is performed by detecting the number of rotations of the gear 53 and thus the driving sprocket 45.

FIG. 10 is an overall side view of an auxiliary powered bicycle provided with a driving device according to a third embodiment of the present invention. FIG. 11 is a diagram illustrating a state where the cover of the case is removed from the bicycle driving device illustrated in FIG. 10. FIG. 12 shows FIG.
FIG. 4 is a cross-sectional view taken along the line ABCDE of FIG.

FIGS. 11 to 14 show a driving device according to the third embodiment of the present invention. As shown in the figure, the crankshaft 5 and the planet carrier 57 are coaxially fixed by the serration portion 5a, and the rotational torque input from the crankshaft 5 is applied to the planetary gear 58 supported by the planet carrier via the planet carrier 57. While rotating around the support shaft, the inner gear 59 and the sun gear 56 are rotated.
The sun gear 56 and the arm 60 are integrated by a serration portion 60a, and the tip of the arm 60 is supported by the case 4 via a coil spring 62 described later. Therefore, the rotational torque input from the crankshaft 5 causes the internal gear 59 to transmit torque in the same direction as the input rotation via the planet carrier 57 and the planetary gear 58. The rotation of the front gear 11 fastened and fixed to the internal gear 59
Since the power is transmitted to the rear wheel 2 by the transmission by the transmission 4, the vehicle can be used as a bicycle by a normal pedaling operation.

As shown in FIGS. 13 and 14, the arm 60 fixed to the sun gear 56 receives a torque as a reaction torque of the front gear 11 in the same direction as the rotation direction of the front gear 11. Therefore, the contact receiver 6 provided at the tip of the arm 60
3 receives a reaction force from the coil spring 62 via the spring receiver 64 so as to be balanced with the reaction torque. The arm 60 is rotatable around the crankshaft 5, and the reaction torque also fluctuates according to the magnitude of the input torque of the crankshaft.
The amount of compression of the coil spring 62 is changed. Therefore, the contact receiving seat 63 is displaced around the crankshaft 5 according to the input torque of the crankshaft 5, and the input torque is detected by detecting the amount of displacement by the contact 61 a of the displacement sensor 61.

By adopting the configuration as in the third embodiment, the same effects as those of the second embodiment can be obtained, and in addition, the speed increasing action of the planetary gear mechanism for detecting the reaction torque can be achieved. The size of the front gear can be reduced, so that it is less likely to hinder the driver's foot during the pedaling operation, and the effect of improving the appearance of the entire bicycle is produced. In the above example, the planetary gear mechanism for detecting the reaction torque is of an external type, but it may be provided inside a case such as the case 4 in the second embodiment.

Although the present invention has been described with reference to the illustrated example, the present invention is not limited to the above example. For example, as disclosed in Japanese Patent Application No. 7-103484 by the applicant of the present invention, The shaft, the front gear rotatably arranged on the crankshaft, and the two ends of the cylindrical member loosely inserted on the crankshaft are coupled to each other, and the torsion of the cylindrical member is detected by a magnetostrictive detector. Thus, the input torque of the crankshaft may be detected.

[0036]

As described above, according to the present invention, in a bicycle provided with a power transmission auxiliary power device together with a human-powered power transmission device, the axis of the auxiliary power motor and the axis of the crankshaft are arranged substantially in parallel. In addition, since the first-stage speed reduction transmission mechanism of the motor is a belt transmission mechanism, noise is less generated, the required accuracy is reduced, and the belt speed is reduced as compared with a conventional reduction gear transmission using a gear train. The transmission does not require lubrication.

Further, the backlash of the gear transmission is absorbed by the initial tension of the belt, and the shock at the time of starting the motor due to the backlash is reduced by the elasticity of the belt. Further, since the belt pulley can be made lighter with a light alloy or the like, the load on the motor for auxiliary power can be reduced.

Further, in the present invention, since the position of the displacement sensor of the driving device of the bicycle with auxiliary power can be adjusted by the adjusting screw, the adjustment of the mounting position of the torque detecting cone in the crankshaft direction is facilitated. Since it is possible to absorb variations in the accuracy of each component, manufacturing costs can be reduced.

Furthermore, since the motor output is transmitted to the small-diameter drive sprocket below the front gear, the reduction gear ratio can be reduced, so that the number of reduction stages can be reduced and the structure can be simplified, and the manufacturing cost can be reduced. it can. Furthermore, since the driving sprocket is wound around the loose side of the chain, a sufficient winding angle can be obtained, the load on the sprocket teeth can be reduced, and the occurrence of tooth skipping can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view of an auxiliary powered bicycle having a driving device according to a first embodiment of the present invention.

2 is an elevational view showing a transmission system of a hanger portion of the bicycle of FIG. 1 in a state where a side cover of a case is removed from a back surface of FIG. 1;

FIG. 3 is a plan view showing a section taken along a cutting line of ABCD-DE in FIG. 2;

FIG. 4 is a plan view showing a cross section taken along the line ABFDE of FIG. 2;

FIG. 5 is an exploded perspective view of each member on the crankshaft.

FIG. 6 is a side view of an auxiliary powered bicycle including a driving device according to a second embodiment of the present invention.

7 is a plan view of the driving device shown in FIG. 6 in a state where a side cover of a case is removed from the front in FIG. 6;

8 is a cross-sectional view of the driving device shown in FIG. 7 taken along the line ABCD-DE.

9 is a cross-sectional view of the driving device shown in FIG. 7 taken along the line ABCFCE.

FIG. 10 is a side view of an auxiliary powered bicycle including a driving device according to a third embodiment of the present invention.

FIG. 11 shows a driving device according to a third embodiment of the present invention;
It is a top view showing the state where the side cover was removed.

12 is a cross-sectional view of the driving device shown in FIG. 11 taken along the line ABCD.

FIG. 13 is a diagram showing a rotation direction of a gear and a direction in which torque is generated in the drive device shown in FIG. 11;

FIG. 14 is a sectional view showing a torque detector of the drive device shown in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front wheel 2 Rear wheel 3 Body (frame) 4 Case 4a Case body 4b, 4c Side cover 4d Bottom case 5 Crankshaft 5a Serration part 6, 7, 8 Bearing 9 Crank arm 10 Pedal 11 Front gear (front sprocket) 12 Rear gear (Rear sprocket) 13 Rear axle 14 Chain 15 Motor 15a shaft 16 Battery (battery) 17 Control circuit (Controller) 18 Driving disk 19 One-way clutch 20 Bearing 21, 21 'Followed disk 22 Spring plate 23, 24 pin 25 Torque Detection cone 26 Coil spring 27 Stop ring 28 Guide fitting 29 Displacement sensor 29a Contact 30 Return spring 31 Adjustment screw 32, 33 Shaft 34, 35, 36, 37 Bearing 38 Pulley for small-diameter timing belt 39 Direction clutch 40 Pulley for large diameter timing belt 41 Timing belt 42 Small gear 43 Large gear 44 Small gear 45 Drive sprocket 46 Hanger pipe 47,48 Pulley 49 Timing belt 50,51,52,53 Gear 54,54 'Rotation sensor 55 One-way clutch 56 Sun gear 57 Planet carrier 58 Planet gear 59 Internal gear 60 Arm 60a Serration part 61 Displacement sensor 61a Contact 63 Contact holder 62 Coil spring 64 Spring support

Continued on the front page (72) Inventor Toshiharu Furukawa 3-1-1 Nakazuma, Ageo-shi, Saitama Pref. Within Stone Cycle Co., Ltd. (72) Inventor Yuki Sato 3-1-1, Nakazuma, Ageo-shi, Saitamaヂ Inside Stone Cycle Co., Ltd.

Claims (7)

[Claims] 1. A bicycle provided with an auxiliary power device driven by electric power together with a power transmission device driven by human power, wherein an axis of an auxiliary power motor and an axis of a crankshaft are arranged substantially in parallel.
A drive device for a bicycle with auxiliary power, wherein a belt transmission mechanism is used as a first-stage reduction transmission mechanism of the motor. 2. A drive disk is provided on a crankshaft of a bicycle via a one-way clutch, and a driven gear integrated with a front gear is rotatably provided on the crankshaft, and between the driven gear and the drive disk. A rotational phase difference is generated between the driving disk and the driven gear in accordance with a change in the transmission torque of the torque detecting member, and a torque detecting member that moves in the axial direction of the crankshaft by the rotational phase difference is provided. A displacement sensor for detecting displacement is provided, and a motor for auxiliary power is driven through a control circuit for inputting an output signal of the displacement sensor.A shaft of the motor is provided in parallel with the crankshaft, and a motor is provided. Auxiliary power is transmitted to the driven gear via a reduction mechanism, and a first-stage reduction transmission mechanism of the reduction mechanism is a toothed belt transmission mechanism. Bicycle drive. 3. A driving device for a bicycle with auxiliary power, wherein a position of a displacement sensor of the device according to claim 2 can be adjusted by an adjusting screw. 4. A bicycle provided with an electric power-driven auxiliary power device together with a human-powered power transmission device, wherein the axis of the auxiliary power motor and the axis of the crankshaft are arranged substantially in parallel,
A drive sprocket to which auxiliary power is transmitted from the motor is provided below and below the front gear in order to connect the motor and the first-stage deceleration transmission mechanism with a belt and to provide auxiliary power from the loose side of the chain. A bicycle drive device with an auxiliary power. 5. A bicycle provided with an auxiliary power unit driven by electric power together with a power transmission unit driven by human power, a driving disk provided on a crankshaft via a one-way clutch, and a driven disk integrated with a front gear is used as a crank. A shaft is rotatably provided, and a rotational phase difference is generated between the driving disk and the driven disk in accordance with a change in transmission torque between the driven disk and the driving disk. A torque detecting member that moves in the axial direction of the crankshaft according to the occurrence of the phase difference, and a displacement sensor that detects displacement of the torque detecting member are provided. Auxiliary power is supplied via a control circuit that inputs an output signal of the displacement sensor. And a motor shaft is provided substantially parallel to the crankshaft, and the motor transmits auxiliary power to a driving sprocket provided below and below the front gear via a speed reduction mechanism. A drive device for a bicycle with auxiliary power, wherein the first-stage speed reduction transmission mechanism of the speed reduction mechanism is a toothed belt transmission mechanism. 6. A bicycle provided with an auxiliary power drive device driven by electric power together with a power transmission device driven by human power, wherein a planet carrier is fixed to a crankshaft, and a plurality of planet gears are provided on the same circumference of the planet carrier. A driven rotator, which is rotatably mounted on the shaft and integrally formed with a front gear and an internal gear, is rotatably provided outside these planetary gears, and the internal gear meshes with the planetary gear while the planetary gear is engaged. Inside the gear,
A sun gear that meshes with those planetary gears and rotates by the reaction torque of the crankshaft input torque is rotatably provided, and torque detection means for detecting this reaction torque is provided.
The auxiliary power motor is driven through a control circuit for inputting an output signal of the torque detecting means, and the motor shaft is provided substantially in parallel with the crankshaft. The auxiliary power is transmitted to a driving sprocket provided at the rear lower side.
A drive device for a bicycle with auxiliary power, wherein a reduction transmission mechanism of a step is a toothed belt transmission mechanism. 7. The torque detecting means includes an arm and a contact receiving seat of the torque detecting means provided on the sun gear, and a spring interposed between the contact receiving seat and the case,
7. The bicycle with an auxiliary power according to claim 6, further comprising a displacement sensor that changes a displacement amount of an end portion of the spring with a change in a reaction torque of a crankshaft input torque and detects the displacement amount. Drive.