JP2008137517A - Drive device for electric assistant bicycle and electric assistant bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance handling property of an electric assistant bicycle by promoting weight reduction of a drive device 9 for the electric assistant bicycle, in other words, weight reduction of the electric assistant bicycle 1. <P>SOLUTION: A circular drive plate 21 is concentrically provided on a pedal crank shaft 13, a winding part 29 is formed on an outer peripheral surface of a flange 25 of the drive plate 21, and a ring gear part 31 is formed on an inner peripheral surface of the flange 25 of the drive plate 21. An electric motor 35 is provided on a casing 11 concentrically to the pedal crank shaft 13, and a sun gear 55 connectable to a motor rotor of the electric motor 35 is rotatably and concentrically provided on the pedal crank shaft 13. A plurality of planetary gears 61 engaged with the ring gear part 31 and the sun gear 55 are arranged on a predetermined circumference C on which a pedal is concentric to the pedal crank shaft 13, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrically assisted bicycle that travels in a forward direction by electric power driving in addition to human power driving, and an electric assist bicycle driving device that rotates a rear wheel of the electrically assisted bicycle.

  With the recent spread of electrically assisted bicycles, various developments have been made on electrically assisted bicycle drive devices, and there are those shown in Patent Document 1 as the prior art, and the configuration of the assist bicycle drive device according to the prior art is as follows: It becomes as follows.

  That is, a casing is provided on the body frame of the electrically assisted bicycle, and a pedal crankshaft is rotatably provided in the casing. The pedal crankshaft is concentrically provided with a resultant force shaft, and the resultant force shaft has an endless chain (power transmission member) for transmitting rotational force to the rear wheel side of the electrically assisted bicycle. The sprocket which can wind is provided.

  An intermediate shaft is provided by concentric spline fitting at a position adjacent to the resultant force shaft of the pedal crankshaft, and this intermediate shaft is connected to the resultant force shaft via a one-way clutch. In the casing, an electric motor is provided in parallel with the pedal crankshaft. The electric motor is provided on a motor stator fixed to the casing and rotatably provided on the inner side of the motor stator. The motor rotor and a motor output shaft connectable to the motor rotor via another one-way clutch. A reduction mechanism such as a plurality of reduction gears is provided between the crankshaft and the electric motor in the casing, and this reduction mechanism is linked to the motor output shaft and the resultant shaft of the electric motor. .

  Therefore, by rotating the pedal crankshaft in one direction by human power driving, the intermediate shaft, the resultant force shaft, and the sprocket are integrally rotated in one direction to circulate the chain. Thereby, the rotational force can be transmitted to the rear wheel side, and the electrically assisted bicycle can travel in the forward direction.

Then, while the electric assist bicycle is running, the motor rotor and the motor output shaft are integrally rotated by driving the electric motor, whereby the one-way rotational force is transmitted to the sprocket by the speed reduction mechanism. Thus, the electrically assisted bicycle can be driven in the forward direction by electric power driving in addition to human power driving.
Japanese Patent No. 2660460

  By the way, in the electric assist bicycle drive apparatus according to the above-described prior art, since the electric motor is provided in parallel to the pedal crankshaft, the electric assist bicycle drive apparatus is only in the longitudinal direction of the pedal crankshaft. However, it tends to expand in a direction perpendicular to the longitudinal direction. Therefore, there is a problem that the weight of the electrically assisted bicycle drive device is increased, in other words, the weight of the electrically assisted bicycle is increased, and it becomes difficult to improve the handleability of the electrically assisted bicycle.

  Therefore, the present invention can solve the above-described problems, and thus can be prevented from expanding in a direction orthogonal to the longitudinal direction of the pedal crankshaft. The purpose is to provide an assist bicycle.

  A first feature of the present invention (feature of the invention described in claim 1) is an electrically assisted bicycle drive device for rotating a rear wheel in an electrically assisted bicycle, which is rotatably provided on a body frame of the electrically assisted bicycle. A pedal crankshaft and an endless power transmission member that is concentrically provided on the pedal crankshaft, has a flange on the peripheral side, and transmits a rotational force to the rear wheel side on the outer peripheral surface of the flange A circular drive plate having a ring gear portion formed on the inner peripheral surface of the flange, the vehicle body frame concentrically with the pedal crankshaft, and the vehicle body frame. An electric motor comprising a motor stator fixed to the motor stator and a motor rotor rotatably provided on the motor stator; A sun gear that is concentrically provided and connectable to the motor rotor, and a plurality of planetary gears that are arranged on a predetermined circumference concentric with the pedal crankshaft and mesh with the ring gear portion and the sun gear; The gist is that

  Note that “provided” means not only directly provided but also indirectly provided via an intermediate member. Similarly, “fixed” means directly In addition to being fixed, it is intended to include being indirectly fixed via an intermediate member. The power transmission member includes a belt, a chain, and the like.

  According to the first feature, by rotating the pedal crankshaft in one direction by manual driving, the drive plate is rotated in one direction and the power transmission member is circulated. Thereby, a rotational force can be transmitted to the rear wheel side, and the electric assist bicycle can travel in the forward direction.

  Further, during the traveling of the electric assist bicycle, the motor rotor and the sun gear are integrally rotated in the other direction by driving the electric motor, thereby meshing the plurality of planetary gears and the ring gear portions. Due to the action, a rotational force in one direction is transmitted to the drive plate. Thus, the electric assist bicycle can be driven in the forward direction by electric power driving in addition to human power driving (general operation of the electric assist bicycle driving apparatus).

  In addition to the general operation of the electric assist bicycle drive device described above, the electric motor is provided concentrically with the pedal crankshaft, and the pedal crankshaft can be connected to the motor rotor of the electric motor. The sun gear is provided concentrically, and the plurality of planetary gears meshed with the ring gear portion and the sun gear are respectively arranged on a predetermined circumference concentric with the pedal crankshaft. Main components of the driving device can be arranged along the longitudinal direction of the pedal crankshaft, and the electric assist bicycle driving device is prevented from expanding in a direction perpendicular to the longitudinal direction of the pedal crankshaft. Can do.

  Further, the winding portion capable of winding the power transmission member on the rear wheel side is formed on the outer peripheral surface of the flange of the drive plate, and the ring gear portion is formed on the inner peripheral surface of the flange of the drive plate. Since it is formed, the function as a winding member (pulley or sprocket) for winding the power transmission member and the function as one reduction gear of the reduction mechanism including the sun gear and the plurality of planetary gears are driven. Can also be used as a plate.

  According to a second feature of the present invention (a feature of the invention described in claim 2), in addition to the first feature, each planetary gear is rotatably provided on one side of the motor stator. The gist.

  A third feature of the present invention (a feature of the invention described in claim 3) is that the first feature or the second feature of the electrically assisted bicycle that travels in the forward direction by electric power driving in addition to human power driving. The gist of the invention is that it comprises a drive device for an electrically assisted bicycle.

  According to the invention of any one of claims 1 to 3, it is possible to prevent the electric assist bicycle drive device from expanding in a direction perpendicular to the longitudinal direction of the pedal crankshaft. Therefore, the weight reduction of the electric assist bicycle drive device, in other words, the weight reduction of the electric assist bicycle can be promoted, and the handleability of the electric assist bicycle can be improved.

  In addition, since the function as the winding member for winding the power transmission member and the function as one of the speed reduction gears of the speed reduction mechanism can be shared by the drive plate, By reducing the number of parts, the configuration of the electric assist bicycle drive device can be simplified.

  An embodiment of the present invention will be described with reference to FIGS. 1 to 3.

  Here, FIG. 1 is a cross-sectional view of a drive device for an electrically assisted bicycle according to an embodiment of the present invention, FIG. 2 is a view taken along line II-II in FIG. 1, and FIG. 3 is an embodiment of the present invention. It is a side view of the electrically assisted bicycle. In the figure, “F” indicates the forward direction, and “R” indicates the backward direction.

  As shown in FIG. 1 to FIG. 3, an electrically assisted bicycle 1 according to an embodiment of the present invention is a bicycle that travels forward by electric power driving in addition to human power driving, and is based on a body frame 3. I have. A front wheel 5 is rotatably provided at the front portion of the vehicle body frame 3, and a rear wheel 7 is rotatably provided at the rear portion of the vehicle body frame 3. The hanger portion 3a of the vehicle body frame 3 is provided with an electrically assisted bicycle drive device 9 for rotating the rear wheel 7. The specific configuration of the electrically assisted bicycle drive device 9 is as follows. Become.

  That is, the hanger portion 3a of the vehicle body frame 3 is provided with a casing 11. The casing 11 is provided with a pedal crankshaft 13 rotatably through a bearing 15. In other words, the vehicle body frame 3 3, a pedal crankshaft 13 is rotatably provided through a bearing 15 and a casing 11. Note that the pedal 17 is attached to both ends of the pedal crankshaft 13 eccentrically via a crank 19.

  A circular drive plate 21 is concentrically provided on the pedal crankshaft 13 via a one-way clutch 23, and the drive plate 21 has a flange 25 on the peripheral side. Here, the one-way clutch 23 connects the pedal crankshaft 13 and the drive plate 21 only when the pedal crankshaft 13 rotates in one direction (clockwise direction in FIG. 2). Further, on the outer peripheral surface of the flange 25 of the drive plate 21, a winding portion (a large number of winding teeth) 29 around which an endless belt (power transmission member) 27 that transmits a rotational force to the rear wheel 7 side can be wound. A ring gear portion 31 is formed on the inner peripheral surface of the flange 25 of the drive plate 21. The belt 27 is also wound around a rear wheel pulley 33 provided concentrically on the rear wheel 7.

  In the casing 11, an electric motor 35 is provided concentrically with the pedal crankshaft 13. In other words, the electric motor 35 is connected to the pedal crankshaft 13 via the casing 11 on the hanger portion 3 a of the vehicle body frame 3. It is provided concentrically. The electric motor 35 includes a motor stator 37 fixed to the casing 11 and a motor rotor 41 provided on the motor stator 37 via a bearing 39 so as to be rotatable. Here, the motor rotor 41 has a flange 43 on the outer edge side and a sleeve 47 that is rotatably supported on the pedal crankshaft 13 via a bearing 45 on the inner edge side. The motor stator 37 includes a coil 49, and a magnet 51 is provided on the inner peripheral surface of the flange 43 of the motor rotor 41 so as to face the coil 49. The electric motor 35 is supplied with power by a battery 53 provided in the vicinity of the casing 11 in the body frame 3.

  A sun gear 55 is rotatably and concentrically provided on the pedal crankshaft 13 via a bearing 57, and the sun gear 55 can be connected to the motor rotor 41 via a one-way clutch 59. Here, the one-way clutch 59 connects the sun gear 55 to the motor rotor 41 only when the motor rotor 41 rotates in the other direction (counterclockwise direction in FIG. 2).

  On one side of the motor stator 37, a plurality of planetary gears 61 meshed with the ring gear portion 31 and the sun gear 55 are rotatably provided via bearings 63 and the like. The plurality of planetary gears 61 are connected to the pedal crankshaft. 13 are arranged on a predetermined circumference C concentric with 13.

  Although not shown, a torque detector that detects the torque of the pedal crankshaft 13 is provided in the casing 11, and the electric motor 35 is driven and controlled according to a detection value from the torque detector. It is like that.

  Then, the effect | action and effect of embodiment of this invention are demonstrated.

  By stepping on the pedal 17, in other words, by rotating the pedal crankshaft in one direction by manual driving, the drive plate 21 is rotated in one direction and the belt 27 is circulated. Thereby, the rotational force can be transmitted to the rear wheel 7 side, and the electrically assisted bicycle 1 can travel in the forward direction.

  While the electric assist bicycle 1 is traveling, the motor rotor 41 and the sun gear 55 are integrally rotated in the other direction by driving and controlling the electric motor 35 according to the detection value from the torque detector, thereby Due to the meshing action of the planetary gear 61 and the ring gear portion 31, a rotational force in one direction is transmitted to the drive plate 21. Thereby, the electrically assisted bicycle 1 can be driven in the forward direction by electric power driving in addition to human power driving (general operation of the electrically assisted bicycle driving device 9).

  In addition to the general operation of the electric assist bicycle drive device 9 described above, an electric motor 35 is provided concentrically with the pedal crankshaft 13, and can be connected to the motor rotor 41 of the electric motor 35 on the pedal crankshaft 13. Since the sun gear 55 is provided concentrically, and the plurality of planetary gears 61 meshed with the ring gear portion 31 and the sun gear 55 are respectively arranged on a predetermined circumference C concentric with the pedal crankshaft 13, The main components of the drive device 9 can be arranged along the longitudinal direction of the pedal crankshaft 13, and the electric assist bicycle drive device 9 is prevented from expanding in a direction perpendicular to the longitudinal direction of the pedal crankshaft 13. be able to.

  Further, a winding portion 29 capable of winding the belt 27 on the rear wheel 7 side is formed on the outer peripheral surface of the flange 25 of the drive plate 21, and a ring gear portion 31 is formed on the inner peripheral surface of the flange 25 of the drive plate 21. Therefore, the function as a winding member (pulley) for winding the belt 27 and the function as one reduction gear of the reduction mechanism including the sun gear 55 and the plurality of planetary gears 61 can be used in the drive plate 21. it can.

  Therefore, according to the embodiment of the present invention, it is possible to prevent the electric assist bicycle drive device 9 from expanding in a direction orthogonal to the longitudinal direction of the pedal crankshaft 13, and thus the light weight of the electric assist bicycle drive device 9 can be reduced. In other words, the weight reduction of the electrically assisted bicycle 1 can be promoted, and the handleability of the electrically assisted bicycle 1 can be improved.

  Further, since the function as a winding member for winding the belt 27 and the function as one speed reduction gear of the speed reduction mechanism can be shared by the drive plate 21, the number of parts of the electric assist bicycle drive device 9 is reduced. The configuration of the electrically assisted bicycle drive device 9 can be simplified.

  In addition, this invention is not restricted to description of the above-mentioned embodiment, In addition, it can implement in a various aspect. Further, the scope of rights encompassed by the present invention is not limited to these embodiments.

It is sectional drawing of the drive device for electric assist bicycles concerning the embodiment of the present invention. It is the figure along the II-II line in FIG. 1 is a side view of an electrically assisted bicycle according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric assist bicycle 3 Body frame 3a Hanger part 5 Front wheel 7 Rear wheel 9 Electric assist bicycle drive device 11 Casing 13 Pedal crankshaft 21 Drive plate 25 Flange 27 Belt 29 Winding part 31 Ring gear part 35 Electric motor 37 Motor stator 41 Motor rotor 55 Sun gear 63 Bearing

Claims (3)

In the electric assist bicycle drive device for rotating the rear wheel of the electric assist bicycle,
A pedal crankshaft rotatably provided on a body frame in the electrically assisted bicycle;
A winding that is concentrically provided on the pedal crankshaft, has a flange on the peripheral side, and can wind an endless power transmission member that transmits a rotational force to the rear wheel side on the outer peripheral surface of the flange. A circular drive plate in which a turning portion is formed and a ring gear portion is formed on the inner peripheral surface of the flange;
An electric motor comprising a motor stator provided concentrically with the pedal crankshaft on the vehicle body frame and fixed to the vehicle body frame; and a motor rotor provided rotatably on the motor stator;
A sun gear rotatably and concentrically provided on the pedal crankshaft and connectable to the motor rotor;
A plurality of planetary gears respectively disposed on a predetermined circumference concentric with the pedal crankshaft and meshed with the ring gear portion and the sun gear;
An electrically assisted bicycle drive device comprising:   2. The electrically assisted bicycle drive device according to claim 1, wherein each planetary gear is rotatably provided on one side of the motor stator. 3. In an electrically assisted bicycle that travels in the forward direction by electric power driving in addition to human power driving,
An electrically assisted bicycle comprising the drive device for an electrically assisted bicycle according to claim 1.

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