BICYCLE MOTOR UNIT AND BICYCLE DERAILLEUR

A bicycle motor unit comprises an electric motor and a transmitting structure. The electric motor is configured to generate a driving force. The transmitting structure is coupled to the electric motor to transmit the driving force from the electric motor to an actuated device of a bicycle. The transmitting structure includes a first rotatable member, a second rotatable member, and a resisting structure. The first rotatable member is rotatable about a rotational axis. The second rotatable member is rotatable relative to the first rotatable member about the rotational axis. The resisting structure is at least partially provided radially between the first rotatable member and the second rotatable member with respect to the rotational axis so as to resist relative rotation between the first rotatable member and the second rotatable member.

BACKGROUND

Technical Field

The present invention relates to a bicycle motor unit and a bicycle derailleur.

Background Information

A human-powered vehicle includes a motor device coupled to a movable part to move the movable part. An external rotational force is input to the motor device in a case where the movable part receives an external force caused by a physical contact between an obstacle and the movable part. It is preferable to reduce an impact of the external rotational force on the motor device.

SUMMARY

In accordance with a first aspect of the present invention, a bicycle motor unit comprises an electric motor and a transmitting structure. The electric motor is configured to generate a driving force. The transmitting structure is coupled to the electric motor to transmit the driving force from the electric motor to an actuated device of a bicycle. The transmitting structure includes a first rotatable member, a second rotatable member, and a resisting structure. The first rotatable member is rotatable about a rotational axis. The second rotatable member is rotatable relative to the first rotatable member about the rotational axis. The resisting structure is at least partially provided radially between the first rotatable member and the second rotatable member with respect to the rotational axis so as to resist relative rotation between the first rotatable member and the second rotatable member.

With the bicycle motor unit according to the first aspect, the resisting structure provides resistance to the relative rotation between the first rotatable member and the second rotatable member. Thus, the resisting structure reduces a rotational force transmitted between the first rotatable member and the second rotatable member when an external force is applied to at least one of the first rotatable member and the second rotatable member. Accordingly, it is possible to reduce an impact of the external force on the electric motor.

In accordance with a second aspect of the present invention, the bicycle motor unit according to the first aspect is configured so that the first rotatable member is radially spaced apart from the second rotatable member with respect to the rotational axis.

With the bicycle motor unit according to the second aspect, it is possible to utilize a space between the first rotatable member and the second rotatable member.

In accordance with a third aspect of the present invention, the bicycle motor unit according to the first or second aspect is configured so that the second rotatable member is at least partially provided radially inwardly of the first rotatable member with respect to the rotational axis.

With the bicycle motor unit according to the third aspect, it is possible to utilize a radially inner space of the first rotatable member for a space where the second rotatable member is at least partially provided. Thus, it is possible to make the transmitting structure comparatively compact.

In accordance with a fourth aspect of the present invention, the bicycle motor unit according to any one of the first to third aspects is configured so that the resisting structure includes a resisting member. The resisting member is a separate member from at least one of the first rotatable member and the second rotatable member.

With the bicycle motor unit according to the fourth aspect, it is possible to improve design flexibility of the bicycle motor unit.

In accordance with a fifth aspect of the present invention, the bicycle motor unit according to the fourth aspect is configured so that the resisting member includes a slidable member configured to slidably contact at least one of the first rotatable member and the second rotatable member.

With the bicycle motor unit according to the fifth aspect, it is possible to provide resistance using a frictional force generated between the slidable member and the at least one of the first rotatable member and the second rotatable member.

In accordance with a sixth aspect of the present invention, the bicycle motor unit according to any one of the first to fifth aspects is configured so that the first rotatable member includes a first coupling portion coupled to the resisting structure. The second rotatable member includes a second coupling portion coupled to the resisting structure.

With the bicycle motor unit according to the sixth aspect, the resisting structure reliably provides the resistance to the relative rotation between the first rotatable member and the second rotatable member. Thus, the resisting structure reliably reduces the rotational force transmitted between the first rotatable member and the second rotatable member when the external force is applied to at least one of the first rotatable member and the second rotatable member. Accordingly, it is possible to reliably reduce the impact of the external force on the electric motor.

In accordance with a seventh aspect of the present invention, the bicycle motor unit according to the sixth aspect is configured so that the second coupling portion is at least partially provided radially inwardly of the first coupling portion.

With the bicycle motor unit according to the seventh aspect, it is possible to utilize a radially inner space of the first coupling portion for a space where the second coupling portion is at least partially provided. Thus, it is possible to make the transmitting structure comparatively compact.

In accordance with an eighth aspect of the present invention, the bicycle motor unit according to the sixth aspect is configured so that the second coupling portion is at least partially provided radially outwardly of the first coupling portion.

With the bicycle motor unit according to the eighth aspect, it is possible to utilize a radially outer space of the first coupling portion for a space where the second coupling portion is at least partially provided. Thus, it is possible to make the transmitting structure comparatively compact.

In accordance with a ninth aspect of the present invention, the bicycle motor unit according to any one of the sixth to eighth aspects is configured so that the first coupling portion includes a first contact surface contactable with the resisting structure. The second coupling portion includes a second contact surface contactable with the resisting structure. The first contact surface is radially spaced apart from the second contact surface with respect to the rotational axis.

With the bicycle motor unit according to the ninth aspect, the resisting structure provides the resistance between the first contact surface and the resisting structure and/or between the second contact surface and the resisting structure. Thus, the resisting structure reliably reduces the rotational force transmitted between the first rotatable member and the second rotatable member when the external force is applied to at least one of the first rotatable member and the second rotatable member. Accordingly, it is possible to reliably reduce the impact of the external force on the electric motor.

In accordance with a tenth aspect of the present invention, the bicycle motor unit according to any one of the sixth to ninth aspects is configured so that the first rotatable member includes a first protruding portion. The first protruding portion is provided radially closer to the second rotatable member than the first coupling portion with respect to the rotational axis.

With the bicycle motor unit according to the tenth aspect, the first protruding portion makes an orientation of the second rotatable member more stable relative to the first rotatable member.

In accordance with an eleventh aspect of the present invention, the bicycle motor unit according to the tenth aspect is configured so that the first protruding portion at least partially overlaps the resisting structure as viewed along the rotational axis.

With the bicycle motor unit according to the eleventh aspect, the first protruding portion restricts the resisting structure from moving along the rotational axis.

In accordance with a twelfth aspect of the present invention, the bicycle motor unit according to any one of the sixth to eleventh aspects is configured so that the second rotatable member includes a second protruding portion. The second protruding portion is provided radially closer to the first rotatable member than the second coupling portion with respect to the rotational axis.

With the bicycle motor unit according to the twelfth aspect, the second protruding portion makes an orientation of the first rotatable member more stable relative to the second rotatable member.

In accordance with a thirteenth aspect of the present invention, the bicycle motor unit according to the twelfth aspect is configured so that the second protruding portion at least partially overlaps the resisting structure as viewed along the rotational axis.

With the bicycle motor unit according to the thirteenth aspect, the second protruding portion restricts the resisting structure from moving along the rotational axis.

In accordance with a fourteenth aspect of the present invention, the bicycle motor unit according to any one of the sixth to thirteenth aspects is configured so that the second rotatable member includes a radially inner portion provided radially inwardly of the second coupling portion with respect to the rotational axis. The first coupling portion is at least partially provided radially between the second coupling portion and the radially inner portion with respect to the rotational axis.

With the bicycle motor unit according to the fourteenth aspect, it is possible to utilize a space between the second coupling portion and the radially inner portion for a space where the first coupling portion is at least partially provided. Thus, it is possible to make the transmitting structure comparatively compact.

In accordance with a fifteenth aspect of the present invention, the bicycle motor unit according to the fourteenth aspect is configured so that the second rotatable member includes a second extending portion extending between the radially inner portion and the second coupling portion such that the second coupling portion is rotatable integrally with the radially inner portion about the rotational axis.

With the bicycle motor unit according to the fifteenth aspect, the second extending portion makes the second coupling portion and the radially inner portion integrally rotatable about the rotational axis.

In accordance with a sixteenth aspect of the present invention, the bicycle motor unit according to any one of the first to fifteenth aspects is configured so that the first rotatable member is operatively coupled to the electric motor to receive the driving force from the electric motor. The second rotatable member is configured to receive the driving force from the electric motor via the resisting structure and the first rotatable member.

With the bicycle motor unit according to the sixteenth aspect, the resisting structure and the first rotatable member transmit the driving force from the electric motor to the second rotatable member. Thus, it is possible to output the driving force from the second rotatable member.

In accordance with a seventeenth aspect of the present invention, the bicycle motor unit according to any one of the first to sixteenth aspects is configured so that the first rotatable member includes a first gear. The first gear is configured to mesh with a first additional gear to receive the driving force from the electric motor via the first additional gear.

With the bicycle motor unit according to the seventeenth aspect, it is possible to transmit the driving force from the electric motor to the first rotatable member via a comparatively simple structure such as the first gear and the first additional gear.

In accordance with an eighteenth aspect of the present invention, the bicycle motor unit according to any one of the first to seventeenth aspects is configured so that the second rotatable member includes a second gear. The second gear is configured to mesh with a second additional gear to transmit the driving force to the second additional gear.

With the bicycle motor unit according to the eighteenth aspect, it is possible to output the driving force from the second rotatable member via a comparatively simple structure such as the second gear and the second additional gear.

In accordance with a nineteenth aspect of the present invention, the bicycle motor unit according to the eighteenth aspect is configured so that the first rotatable member includes a hole extending along the rotational axis. The second gear is at least partially provided in the hole.

With the bicycle motor unit according to the nineteenth aspect, it is possible to utilize the hole for a space where the second coupling portion is at least partially provided. Thus, it is possible to make the transmitting structure comparatively compact.

In accordance with a twentieth aspect of the present invention, the bicycle motor unit according to any one of the sixth to fifteenth aspects is configured so that the first rotatable member includes a first gear. The first gear is configured to mesh with a first additional gear to receive the driving force from the electric motor via the first additional gear. The first gear is coupled to the first coupling portion.

With the bicycle motor unit according to the twentieth aspect, it is possible to transmit the driving force from the electric motor to the first rotatable member via a comparatively simple structure such as the first gear and the first additional gear.

In accordance with a twenty-first aspect of the present invention, the bicycle motor unit according to the twentieth aspect is configured so that the first coupling portion extends from the first gear along the rotational axis.

With the bicycle motor unit according to the twenty-first aspect, it is possible to improve design flexibility of the first coupling portion and the first gear.

In accordance with a twenty-second aspect of the present invention, the bicycle motor unit according to the twentieth or twenty-first aspect is configured so that the second rotatable member includes a second gear. The second gear is configured to mesh with a second additional gear to transmit the driving force to the second additional gear. The second gear is coupled to the second coupling portion.

With the bicycle motor unit according to the twenty-second aspect, it is possible to transmit the driving force from the electric motor to the second rotatable member via a comparatively simple structure such as the second gear and the second additional gear.

In accordance with a twenty-third aspect of the present invention, the bicycle motor unit according to the twenty-second aspect is configured so that the second coupling portion extends from the second gear along the rotational axis.

With the bicycle motor unit according to the twenty-third aspect, it is possible to improve design flexibility of the second coupling portion and the second gear.

In accordance with a twenty-fourth aspect of the present invention, the bicycle motor unit according to any one of the first to twenty-third aspects is configured so that the transmitting structure includes a radial support provided radially between the first rotatable member and the second rotatable member with respect to the rotational axis.

With the bicycle motor unit according to the twenty-fourth aspect, the radial support makes the first rotatable member and the second rotatable member more stable with respect to the rotational axis.

In accordance with a twenty-fifth aspect of the present invention, the bicycle motor unit according to the twenty-fourth aspect is configured so that the radial support is a separate member from the first rotatable member and the second rotatable member.

With the bicycle motor unit according to the twenty-fifth aspect, it is possible to improve design flexibility of at least one of the radial support, the first rotatable member, and the second rotatable member.

In accordance with a twenty-sixth aspect of the present invention, the bicycle motor unit according to the twenty-fourth or twenty-fifth aspect is configured so that the radial support is contactable with at least one of the first rotatable member and the second rotatable member to reduce a radial movement of the second rotatable member relative to the first rotatable member.

With the bicycle motor unit according to the twenty-sixth aspect, the radial support reliably makes the first rotatable member and the second rotatable member more stable with respect to the rotational axis.

In accordance with a twenty-seventh aspect of the present invention, the bicycle motor unit according to any one of the first to twenty-sixth aspect further comprises a restricting member. The restricting member is coupled to at least one of the first rotatable member and the second rotatable member to restrict a relative movement between the first rotatable member and the second rotatable member along the rotational axis.

With the bicycle motor unit according to the twenty-seventh aspect, the restricting member restricts the relative movement between the first rotatable member and the second rotatable member along the rotational axis. Thus, it is possible to make the relative position between the first rotatable member and the second rotatable member more stable along the rotational axis.

In accordance with a twenty-eighth aspect of the present invention, the bicycle motor unit according to any one of the first to twenty-seventh aspects is configured so that the resisting structure allows relative rotation between the first rotatable member and the second rotatable member in response to input of a predetermined rotational force transmitted from at least one of the first rotatable member and the second rotatable member.

With the bicycle motor unit according to the twenty-eighth aspect, the first rotatable member and the second rotatable member are relatively rotated in response to the predetermined rotational force. Thus, it is possible to reduce the predetermined rotational force outputted from the transmitting structure or to restrict the predetermined rotational force from being transmitted between the first rotatable member and the second rotatable member. Thus, it is possible to reliably reduce the impact of the external force on the electric motor.

In accordance with a twenty-ninth aspect of the present invention, the bicycle motor unit according to any one of the first to twenty-eighth aspects further comprises a housing including an internal space. The transmitting structure being at least partially provided in the internal space.

With the bicycle motor unit according to the twenty-ninth aspect, it is possible to protect the transmitting structure at least partially.

In accordance with a thirtieth aspect of the present invention, the bicycle motor unit according to the twenty-ninth aspect is configured so that the second rotatable member includes a first axial end and a second axial end. The second rotatable member extends between the first axial end and the second axial end along the rotational axis. At least one of the first axial end and the second axial end is rotatably supported by the housing about the rotational axis.

With the bicycle motor unit according to the thirtieth aspect, it is possible to stabilize an orientation of the second rotatable member.

In accordance with a thirty-first aspect of the present invention, a bicycle derailleur comprises a base member, a chain guide, and the bicycle motor unit according to any one of the first to thirtieth aspects. The chain guide is movably coupled to the base member. The bicycle motor unit is provided to the base member to apply the driving force to the chain guide.

With the bicycle motor unit according to the thirty-first aspect, it is possible to apply the bicycle motor unit to the bicycle derailleur.

DESCRIPTION OF THE EMBODIMENTS

First Embodiment

As seen inFIG.1, a bicycle2includes a bicycle derailleur RD in accordance with a first embodiment. The bicycle2further includes a vehicle body2A, a saddle2B, a handlebar2C, an operating device3, an operating device4, and a drive train DT. The operating devices3and4are configured to be mounted to the handlebar2C. The drive train DT includes a crank CR, a front sprocket assembly FS, a rear sprocket assembly RS, a chain C, a bicycle derailleur FD, and the bicycle derailleur RD. The front sprocket assembly FS is secured to the crank CR. The rear sprocket assembly RS is rotatably mounted to the vehicle body2A. The chain C is engaged with the front sprocket assembly FS and the rear sprocket assembly RS. The bicycle derailleur RD is mounted to the vehicle body2A and is configured to shift the chain C relative to a plurality of sprockets of the rear sprocket assembly RS to change a gear position. The bicycle derailleur FD is configured to shift the chain C relative to a plurality of sprockets of the front sprocket assembly FS.

In the illustrated embodiment, the bicycle derailleur RD is applied to a road bike. However, the bicycle derailleur RD can be applied to an any kind of bicycles such as a mountain bike, a road bike, a city bike, a cargo bike, a hand bike, and a recumbent bike if needed and/or desired. Furthermore, the bicycle derailleur RD or modifications thereof can be applied to an electric bike (E-bike). The electric bike includes an electrically assisted bicycle configured to assist propulsion of a vehicle with an electric motor33. The structure of the bicycle derailleur RD can be applied to the structure of the bicycle derailleur FD.

The bicycle derailleur RD is configured to be operated using the operating device3. The bicycle derailleur FD is configured to be operated using the operating device4. The bicycle derailleur RD is configured to be electrically connected to the operating devices3and4. The bicycle derailleur RD is configured to be electrically connected to the bicycle derailleur FD.

In the first embodiment, the bicycle derailleur RD is configured to be wirelessly connected to the operating devices3and4. The bicycle derailleur RD is configured to be wirelessly connected to the bicycle derailleur FD. The bicycle derailleur RD can be configured to be wirelessly communicate with the bicycle derailleur FD via at least one of a cycle computer, smart phone, a tablet, and a personal computer. The bicycle derailleur RD is configured to change the gear position in response to a control signal transmitted from the operating device3. The bicycle derailleur RD is configured to transmit, to the bicycle derailleur FD, a control signal transmitted from the operating device4. The bicycle derailleur FD is configured to change the gear position in response to the control signal transmitted from the operating device4via the bicycle derailleur RD. Each of the bicycle components RD and FD includes an electric power source such as a battery. However, at least one of the bicycle components RD and FD can be electrically connected to another electric power source such as a battery via an electric cable if needed and/or desired. Both the bicycle derailleur RD and the bicycle derailleur FD can be electrically connected to another electric power source such as a battery via an electric cable if needed and/or desired.

In the first embodiment, the bicycle derailleur RD includes a rear derailleur, and the bicycle derailleur FD includes a front derailleur. Namely, the bicycle derailleur RD can also be referred to as a bicycle rear derailleur RD. The bicycle derailleur FD can also be referred to as a bicycle front derailleur FD. Structures of the bicycle derailleur RD can be applied to other bicycle components such as the bicycle derailleur FD if needed and/or desired.

In the present application, the following directional terms “front,” “rear,” “forward,” “rearward,” “left,” “right,” “transverse,” “upward” and “downward” as well as any other similar directional terms refer to those directions which are determined on the basis of a user (e.g., a rider) who is in the user's standard position (e.g., on the saddle2B or a seat) in the bicycle2with facing the handlebar2C. Accordingly, these terms, as utilized to describe the bicycle derailleur RD or other components, should be interpreted relative to the bicycle2equipped with the bicycle derailleur RD as used in an upright riding position on a horizontal surface.

As seen inFIG.2, the bicycle derailleur RD comprises a base member12and a chain guide14. The base member12is configured to be coupled to the vehicle body2A. The base member12is configured to be coupled to the vehicle body2A with a derailleur fastener15. The chain guide14is movably coupled to the base member12. The bicycle derailleur RD comprises a linkage16. The chain guide14is movably coupled to the base member12via the linkage16.

The base member12is pivotally coupled to the vehicle body2A about the derailleur fastener15. The bicycle derailleur RD includes an adjustment member19. The adjustment member19is configured to change an orientation of the base member12relative to the vehicle body2A about the derailleur fastener15in a state where the derailleur fastener15is loosened. Examples of the adjustment member19include a screw. The derailleur fastener15is tightened to secure the base member12to the vehicle body2A in a state where the base member12is in a position adjusted using the adjustment member19.

As seen inFIG.3, the chain guide14includes a coupling member20, a guide plate22, a guide pulley24, and a tension pulley26. The coupling member20is movably coupled to the base member12via the linkage16. The guide plate22is pivotally coupled to the coupling member20about a pivot axis PA. The guide pulley24is rotatably coupled to the guide plate22. The tension pulley26is rotatably coupled to the guide plate22. The guide pulley24is configured to be engaged with the chain C. The tension pulley26is configured to be engaged with the chain C. The structure of the chain guide14is not limited to the above structure. For example, the coupling member20can be omitted from the chain guide14if needed and/or desired. The chain guide14can also be referred to as a movable member14.

As seen inFIG.2, the linkage16movably couples the base member12and the chain guide14. The linkage16movably couples the base member12and the coupling member20. In the present embodiment, the linkage16includes an outer link28and an inner link30. The outer link28is pivotally coupled to the base member12about a first pivot axis A1. The outer link28is pivotally coupled to the chain guide14(e.g., the coupling member20) about a second pivot axis A2. The inner link30is pivotally coupled to the base member12about a third pivot axis A3. The inner link30is pivotally coupled to the chain guide14(e.g., the coupling member20) about a fourth pivot axis A4. The first to fourth pivot axes A1to A4are parallel to each other. However, one of the outer link28and the inner link30can be omitted from the linkage16if needed and/or desired. The structure of the linkage16is not limited to the above structure. At least one of the first to fourth pivot axes A1to A4can be non-parallel to another of the first to fourth pivot axes A1to A4.

As seen inFIG.4, the inner link30is at least partially provided between the outer link28and a transverse center plane CP of the bicycle2. The transverse center plane CP is defined to be perpendicular to a sprocket rotational axis RA (see e.g.,FIG.2) of the rear sprocket assembly RS (see e.g.,FIG.1).

The bicycle derailleur RD comprises a bicycle motor unit32. The bicycle motor unit32comprises an electric motor33. The electric motor33is configured to generate a driving force. The driving force includes a driving rotational force RF0. In the present application, the term “rotational force” can also be referred to as “torque” or “moment.” The electric motor33is configured to generate the driving rotational force RF0. The electric motor33is configured to generate the driving rotational force RF0to actuate an actuated device of the bicycle2. In the present embodiment, the electric motor33is configured to generate the driving rotational force RF0to move the chain guide14relative to the base member12. However, the electric motor33can be configured to actuate another device other than the bicycle derailleur RD if needed and/or desired.

The bicycle motor unit32is provided to one of the base member12, the chain guide14, and the linkage16. The electric motor33is provided to one of the base member12, the chain guide14, and the linkage16. In the present embodiment, the bicycle motor unit32is provided to the base member12. The electric motor33is provided to the base member12. However, the bicycle motor unit32can be provided to one of the chain guide14and the linkage16if needed and/or desired. The electric motor33can be provided to one of the chain guide14and the linkage16if needed and/or desired.

The bicycle motor unit32is provided to the base member12to apply the driving force (e.g., the driving rotational force RF0) to the chain guide14. The bicycle motor unit32is configured to move at least one of the chain guide14and the linkage16relative to the base member12. In the present embodiment, the bicycle motor unit32is coupled to the linkage16to move the chain guide14via the linkage16. However, the bicycle motor unit32can be directly coupled to the chain guide14to move the chain guide14relative to the base member12if needed and/or desired.

As seen inFIG.2, the bicycle derailleur RD further comprises a power-supply attachment structure34to which an electric power source36is to be attached. The power-supply attachment structure34is configured to detachably hold the electric power source36. The power-supply attachment structure34is electrically connected to the bicycle motor unit32to supply electricity from the electric power source36to the bicycle motor unit32. Examples of the electric power source36include a battery such as a primary battery and a secondary battery. However, the power-supply attachment structure34can be omitted from the bicycle derailleur RD if needed and/or desired. In such embodiments, the bicycle derailleur RD can be configured to be electrically connected to another electric power source if needed and/or desired.

As seen inFIG.5, the power-supply attachment structure34is provided to one of the base member12, the chain guide14, and the linkage16. The bicycle motor unit32is provided to one of the base member12, the chain guide14, and the linkage16. The power-supply attachment structure34is provided to another of the base member12, the chain guide14, and the linkage16. The bicycle motor unit32is provided to one of the base member12and the linkage16. The power-supply attachment structure34is provided to the other of the base member12and the linkage16.

In the present embodiment, the bicycle motor unit32is provided to the base member12. The power-supply attachment structure34is provided to the linkage16. The power-supply attachment structure34is provided to the outer link28. However, the bicycle motor unit32can be provided to one of the chain guide14and the linkage16if needed and/or desired. The bicycle motor unit32can be provided to one of the outer link28and the inner link30if needed and/or desired. The power-supply attachment structure34can be provided to one of the base member12and the chain guide14if needed and/or desired. The power-supply attachment structure34can be provided to the inner link30if needed and/or desired. The power-supply attachment structure34can be omitted from the bicycle motor unit32if needed and/or desired.

The bicycle derailleur RD includes a cover37. The cover37is attached to the base member12. The cover37is secured to the base member12with a fastener37A such as a screw. The adjustment member19is provided at least partially outside the cover37in a cover attachment state where the cover37is attached to the base member12. The cover37includes a hole37B. The adjustment member19extends through the hole37B of the cover37in the cover attachment state.

The base member12includes a connection port12P to which an electric cable EC is electrically connected. The cover37at least partially covers the connection port12P in the cover attachment state. The cover37at least partially covers the electric cable EC in the cover attachment state. The bicycle motor unit32is configured to be powered by electricity supplied from the electric power source36or electricity supplied from an external power source via the electric cable EC. The cover37can be omitted from the bicycle derailleur RD if needed and/or desired.

As seen inFIG.6, the bicycle motor unit32further comprises a housing38including an internal space38S. The transmitting structure60is at least partially provided in the internal space38S. In the present embodiment, the housing38is a separate member from the base member12. However, the housing38can be at least partially provided integrally with the base member12as a one-piece unitary member.

The base member12includes a first base body40, a second base body42, and a fastener44. The first base body40is configured to be coupled to the vehicle body2A (see e.g.,FIG.2) with the derailleur fastener15. The second base body42is a separate member from the first base body40. The second base body42is fastened to the first base body40with the fastener44such as a screw. The bicycle motor unit32is provided between the first base body40and the second base body42. The housing38is held between the first base body40and the second base body42.

As seen inFIG.6, the housing38includes a first housing50and a second housing52. The first housing50and the second housing52define the internal space38S between the first housing50and the second housing52. In the present embodiment, the second housing52is a separate member from the first housing50. However, the second housing52can be integrally provided with the first housing50as a one-piece unitary member if needed and/or desired.

The electric motor33is configured to generate the driving rotational force RF0(see e.g.,FIG.7) using electricity supplied from the electric power source36via the power-supply attachment structure34. The electric motor33is electrically connected to the power-supply attachment structure34. The electric motor33is provided in the internal space38S of the housing38. The electric motor33is provided between the first housing50and the second housing52.

The bicycle motor unit32comprises an output member56. The electric motor33is coupled to the output member56to rotate the output member56relative to the housing38about an output rotational axis A5. The output member56extends along the output rotational axis A5. In the present embodiment, the output rotational axis A5is coincident with the third pivot axis A3. The output member56is rotatable relative to the housing38about the third pivot axis A3. The inner link30is rotatable relative to the base member12about the output rotational axis A5. However, the output rotational axis A5can be offset from the third pivot axis A3if needed and/or desired.

The inner link30is coupled to the output member56to receive, from the output member56, the driving rotational force RF0transmitted from the electric motor33to the output member56. The inner link30is coupled to the output member56to rotate along with the output member56relative to the housing38and the base member12about the third pivot axis A3. The inner link30includes an inner link body30A, an inner link lever30B, and fasteners30C. The inner link body30A is pivotally coupled to the base member12about the third pivot axis A3. The inner link body30A is pivotally coupled to the chain guide14about the fourth pivot axis A4. The inner link lever30B is fastened to the inner link body30A with the fasteners30C. The inner link lever30B is coupled to the output member56to receive, from the output member56, the driving rotational force RF0transmitted from the electric motor33. The inner link lever30B is coupled to the output member56to rotate along with the output member56relative to the housing38and the base member12about the third pivot axis A3.

An external force EF is applied to at least one of the chain guide14and the linkage16in response to a physical contact between an obstacle and the at least one of the chain guide14and the linkage16. Thus, external rotational force ERF is applied to the output member56via the linkage16in response to the external force EF. It is preferable to restrict the external rotational force ERF from being transmitted from at least one of the chain guide14and the linkage16to the electric motor33.

As seen inFIG.7, the bicycle motor unit32comprises a transmitting structure60. The transmitting structure60is coupled to the electric motor33to transmit the driving force (e.g., the driving rotational force RF0) from the electric motor33to the actuated device of the bicycle2. The transmitting structure60is coupled to the electric motor33to transmit the driving force (e.g., the driving rotational force RF0) from the electric motor33to the chain guide14.

The transmitting structure60is coupled to the electric motor33to transmit the driving rotational force RF0from the electric motor33to at least one of the chain guide14and the linkage16. In the present embodiment, the transmitting structure60is coupled to the electric motor33to transmit the driving rotational force RF0from the electric motor33to the chain guide14via the linkage16. However, the transmitting structure60can be configured to transmit the driving rotational force RF0from the electric motor33to the chain guide14via the coupling member20or directly to the chain guide14if needed and/or desired.

The bicycle motor unit32comprises an additional transmitting structure62. The transmitting structure60has a structure different from a structure of the additional transmitting structure62. The additional transmitting structure62is coupled to the electric motor33to transmit the driving rotational force RF0from the electric motor33to the actuated device of the bicycle2. The additional transmitting structure62is coupled to the electric motor33to transmit the driving rotational force RF0from the electric motor33to the chain guide14. The additional transmitting structure62is coupled to the electric motor33to transmit the driving rotational force RF0from the electric motor33to the chain guide14.

The additional transmitting structure62is coupled to the electric motor33to transmit the driving rotational force RF0from the electric motor33to at least one of the chain guide14and the linkage16. In the present embodiment, the additional transmitting structure62is coupled to the electric motor33to transmit the driving rotational force RF0from the electric motor33to the chain guide14via the linkage16. However, the additional transmitting structure62can be configured to transmit the driving rotational force RF0from the electric motor33to the chain guide14via the coupling member20or directly to the chain guide14if needed and/or desired.

The transmitting structure60is provided on a downstream side of the additional transmitting structure62on the power transmission path TP in a first power-transmission direction LD1defined from the electric motor33to the output member56. The transmitting structure60is provided on an upstream side of the additional transmitting structure62on the power transmission path TP in a second power-transmission direction LD2defined from the output member56to the electric motor33.

The bicycle motor unit32further comprises a speed reducer63. The speed reducer63couples the electric motor33and the output member56to transmit the driving rotational force RF0of the electric motor33to the output member56. In the present embodiment, the speed reducer63includes the transmitting structure60and the additional transmitting structure62. However, one of the transmitting structure60and the additional transmitting structure62can be omitted from the speed reducer63if needed and/or desired. The speed reducer63can include structures other than the transmitting structure60and the additional transmitting structure62in additional to the transmitting structure60and the additional transmitting structure62if needed and/or desired.

The electric motor33includes an output shaft33A. The electric motor33includes a motor gear33B and a motor housing33C. The motor gear33B is fastened to the output shaft33A. The electric motor33is configured to rotate the output shaft33A relative to the motor housing33C about a motor rotational axis A9. The electric motor33is configured to generate the driving rotational force RF0.

As seen inFIG.8, the electric motor33is coupled to the additional transmitting structure62. The electric motor33is coupled to the additional transmitting structure62via at least one gear. The speed reducer63includes gears G1, G2, G3, G4, and G5. Namely, the bicycle motor unit32includes the gears G1to G5. The electric motor33is coupled to the additional transmitting structure62via the gears G1to G5. The gear G1meshes with the motor gear33B of the electric motor33. The gear G2is rotatable along with the gear G1relative to the housing38(see e.g.,FIG.16). The gear G2meshes with the gear G3. The gear G4is rotatable along with the gear G3relative to the housing38(see e.g.,FIG.16). The gear G4meshes with the gear G5. The additional transmitting structure62is coupled to the gear G5to receive the driving rotational force RF0generate by the electric motor33via the gears G1to G5.

The additional transmitting structure62is coupled to the transmitting structure60. The additional transmitting structure62is coupled to the transmitting structure60via at least one gear. The speed reducer63includes a gear G6. The gear G6is coupled to the additional transmitting structure62to receive a rotational force from the additional transmitting structure62. The transmitting structure60includes a gear G7. The gear G7meshes with the gear G6. The additional transmitting structure62is coupled to the transmitting structure60via the gears G6and G7. The gear G7can also be referred to as a first gear G7. The gear G6can also be referred to as a first additional gear G6.

As seen inFIG.7, the transmitting structure60includes a gear G8. The output member56includes a shaft56S and an output gear G9. The shaft56S extends along the output rotational axis A5. The output gear G9is coupled to the shaft56S to rotate along with the shaft56S about the output rotational axis A5. The gear G8meshes with the output gear G9. The gear G8can also be referred to as a second gear G8. The output gear G9can also be referred to as a second additional gear G9.

The transmitting structure60is configured to protect the electric motor33from damage caused by the external force EF while allowing the driving rotational force RF0to be transmitted from the electric motor33to at least one of the chain guide14and the linkage16. The transmitting structure60is configured to restrict transmission of force from one of the chain guide14and the linkage16to the electric motor33. The transmitting structure60is configured to reduce transmission of the force from one of the chain guide14and the linkage16to the electric motor33.

The additional transmitting structure62is configured to protect the electric motor33from damage caused by the external force EF while allowing the driving rotational force RF0to be transmitted from the electric motor33to at least one of the chain guide14and the linkage16. The additional transmitting structure62is configured to restrict transmission of the force from one of the chain guide14and the linkage16to the electric motor33. The additional transmitting structure62is configured to reduce transmission of the force from one of the chain guide14and the linkage16to the electric motor33.

The transmitting structure60and the additional transmitting structure62are provided between the electric motor33and the output member56in a power transmission path TP provided from the electric motor33to the output member56. The additional transmitting structure62is provided between the electric motor33and the transmitting structure60on the power transmission path TP provided from the electric motor33to the output member56. The transmitting structure60is provided between the additional transmitting structure62and the output member56on the power transmission path TP. The power transmission path TP is defined from the electric motor33to the output member56through the additional transmitting structure62and the transmitting structure60.

The transmitting structure60is configured to restrict transmission of the force from one of the chain guide14and the linkage16to the additional transmitting structure62. The transmitting structure60is configured to reduce transmission of force from one of the chain guide14and the linkage16to the additional transmitting structure62. The additional transmitting structure62is configured to restrict transmission of force from the transmitting structure60to the electric motor33. The additional transmitting structure62is configured to reduce transmission of force from the transmitting structure60to the electric motor33.

As seen inFIG.9, the transmitting structure60includes a first rotatable member64, a second rotatable member66, and a resisting structure68. The first rotatable member64is rotatable about a rotational axis A6. The second rotatable member66is rotatable relative to the first rotatable member64about the rotational axis A6. InFIG.9, the shape of the resisting structure68is simplified.

As seen inFIG.10, the resisting structure68is at least partially provided radially between the first rotatable member64and the second rotatable member66with respect to the rotational axis A6so as to resist relative rotation between the first rotatable member64and the second rotatable member66. In the present embodiment, the resisting structure68is entirely provided radially between the first rotatable member64and the second rotatable member66with respect to the rotational axis A6so as to resist the relative rotation between the first rotatable member64and the second rotatable member66. However, the resisting structure68can be partially provided radially between the first rotatable member64and the second rotatable member66with respect to the rotational axis A6so as to resist the relative rotation between the first rotatable member64and the second rotatable member66if needed and/or desired.

The first rotatable member64is radially spaced apart from the second rotatable member66with respect to the rotational axis A6. The second rotatable member66is at least partially provided radially inwardly of the first rotatable member64with respect to the rotational axis A6. In the present embodiment, the second rotatable member66is partially provided radially inwardly of the first rotatable member64with respect to the rotational axis A6. However, the second rotatable member66can be entirely provided radially inwardly of the first rotatable member64with respect to the rotational axis A6if needed and/or desired. The first rotatable member64can be at least partially provided radially inwardly of the second rotatable member66with respect to the rotational axis A6if needed and/or desired.

The resisting structure68includes a resisting member70. The resisting member70is a separate member from at least one of the first rotatable member64and the second rotatable member66. In the present embodiment, the resisting member70is a separate member from the first rotatable member64and the second rotatable member66. However, the resisting member70can be integrally provided with at least one of the first rotatable member64and the second rotatable member66as a one-piece unitary member if needed and/or desired. The resisting structure68can be integrally provided with at least one of the first rotatable member64and the second rotatable member66as a one-piece unitary member if needed and/or desired.

The resisting member70includes a slidable member72. The slidable member72is configured to slidably contact at least one of the first rotatable member64and the second rotatable member66. The slidable member72is radially deformable with respect to the rotational axis A6. The slidable member72is radially deformed between the first rotatable member64and the second rotatable member66. The slidable member72can be integrally provided with one of the first rotatable member64and the second rotatable member66as a one-piece unitary member if needed and/or desired.

As seen inFIG.11, the slidable member72circumferentially extends about the rotational axis A6. The slidable member72is configured to slidably contact both the first rotatable member64and the second rotatable member66.

The slidable member72includes a base part72A and at least two slidable parts72B. The base part72A slidably contacts the first rotatable member64. The at least two slidable parts72B slidably contacts the second rotatable member66. The base part72A circumferentially extends about the rotational axis A6. For example, the base part72A has an arc shape. The at least two slidable parts72B protrude radially from the base part72A toward one of the first rotatable member64and the second rotatable member66. The at least two slidable parts72B protrude radially inwardly from the base part72A toward the second rotatable member66. The at least two slidable parts72B are elastically deformable in a radial direction with respect to the rotational axis A6.

However, the at least two slidable parts72B can be arranged to protrude radially outwardly from the base part72A toward the first rotatable member64if needed and/or desired. The base part72A can be configured to slidably contact the second rotatable member66if needed and/or desired. The at least two slidable parts72B can be configured to slidably contact the first rotatable member64if needed and/or desired. The total number of the at least two slidable parts72B is not limited to nine. The resisting member70can include members other than the slidable member72instead of or in addition to the slidable member72if needed and/or desired. The base part72A can have other shapes such as an annular shape if needed and/or desired.

The resisting member70includes a first circumferential end70A and a second circumferential end70B and extends between the first circumferential end70A and the second circumferential end70B. The slidable member72includes the first circumferential end70A and the second circumferential end70B. The base part72A includes the first circumferential end70A and the second circumferential end70B. In the present embodiment, the first circumferential end70A is circumferentially spaced apart from the second circumferential end70B about the rotational axis A6. However, the first circumferential end70A can be integrally coupled to the second circumferential end70B to form a closed loop if needed and/or desired.

The at least two slidable parts72B are integrally provided with the base part72A as a one-piece unitary member. The slidable member72is formed with press working. However, at least one of the at least two slidable parts72B can be a separate part from the base part72A if needed and/or desired.

As seen inFIG.10, the first rotatable member64includes a first coupling portion74coupled to the resisting structure68. The second rotatable member66includes a second coupling portion76coupled to the resisting structure68. The second coupling portion76is at least partially provided radially inwardly of the first coupling portion74. The first coupling portion74has a tubular shape. The first rotatable member64includes a hole64H. The hole64H extends along the rotational axis A6. The first coupling portion74includes the hole264H. The second coupling portion76is at least partially provided in the hole64H.

In the present embodiment, the second coupling portion76is entirely provided radially inwardly of the first coupling portion74. The second coupling portion76is entirely provided in the hole64H. However, the second coupling portion76can be partially provided radially inwardly of the first coupling portion74if needed and/or desired. The second coupling portion76can be partially provided in the hole64H if needed and/or desired. The first coupling portion74can be at least partially provided radially inwardly of the second coupling portion76if needed and/or desired.

The first coupling portion74can also be referred to as a first adjacent portion74or a first contact portion74. The second coupling portion76can also be referred to as a second adjacent portion76or a second contact portion76.

As seen inFIG.12, the resisting structure68at least partially overlaps at least one of the first coupling portion74and the second coupling portion76as viewed in a radial direction with respect to the rotational axis A6. In the present embodiment, the resisting structure68entirely overlaps the first coupling portion74as viewed in the radial direction with respect to the rotational axis A6. The resisting structure68partially overlaps the second coupling portion76as viewed in the radial direction with respect to the rotational axis A6. However, the resisting structure68can be arranged to partially overlap the first coupling portion74as viewed in the radial direction with respect to the rotational axis A6if needed and/or desired. The resisting structure68can be arranged to partially overlap the second coupling portion76as viewed in the radial direction with respect to the rotational axis A6if needed and/or desired.

As seen inFIG.10, the first rotatable member64is operatively coupled to the electric motor33to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33. The second rotatable member66is configured to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33via the resisting structure68and the first rotatable member64. However, the second rotatable member66can be operatively coupled to the electric motor33to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33if needed and/or desired. The first rotatable member64is configured to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33via the resisting structure68and the second rotatable member66if needed and/or desired.

As seen inFIG.7, the first rotatable member64includes the first gear G7. The second rotatable member66includes the second gear G8. The first gear G7is configured to mesh with the first additional gear G6to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33via the first additional gear G6. The second gear G8is configured to mesh with the second additional gear G9to transmit the driving force (e.g., the driving rotational force RF0) to the second additional gear G9. The first gear G7is configured to mesh with the first additional gear G6to receive the driving rotational force RF0from the electric motor33via the first additional gear G6. The second gear G8is configured to mesh with the second additional gear G9to transmit the driving rotational force RF0to the second additional gear G9.

As seen inFIG.10, the first gear G7is coupled to the first coupling portion74. The first coupling portion74extends from the first gear G7along the rotational axis A6. The first gear G7protrudes radially from the first coupling portion74with respect to the rotational axis A6. The first gear G7protrudes radially outwardly from the first coupling portion74with respect to the rotational axis A6. In the present embodiment, the first gear G7is integrally provided with the first coupling portion74as a one-piece unitary member. However, the first gear G7can be a separate member from the first coupling portion74if needed and/or desired.

The second gear G8is coupled to the second coupling portion76. The second coupling portion76extends from the second gear G8along the rotational axis A6. The second gear G8extends from the second coupling portion76along the rotational axis A6. In the present embodiment, the second gear G8is integrally provided with the second coupling portion76as a one-piece unitary member. However, the second gear G8can be a separate member from the second coupling portion76if needed and/or desired.

As seen inFIG.10, the first rotatable member64includes a first protruding portion64P. The first protruding portion64P is provided radially closer to the second rotatable member66than the first coupling portion74with respect to the rotational axis A6. The first protruding portion64P protrudes radially from the first coupling portion74towards the second rotatable member66with respect to the rotational axis A6. Grease can be provided between the first protruding portion64P and the second rotatable member66. Grease can be provided between the first protruding portion64P and the second gear G8.

In the present embodiment, the first protruding portion64P is provided radially inwardly closer to the second rotatable member66than the first coupling portion74with respect to the rotational axis A6. The first protruding portion64P is provided radially inwardly closer to the second gear G8than the first coupling portion74with respect to the rotational axis A6. The first protruding portion64P protrudes radially inwardly from the first coupling portion74towards the second rotatable member66with respect to the rotational axis A6. The first protruding portion64P protrudes radially inwardly from the first coupling portion74towards the second gear G8with respect to the rotational axis A6. The first protruding portion64P has an annular shape.

However, the first protruding portion64P can be provided radially outwardly closer to the second rotatable member66than the first coupling portion74with respect to the rotational axis A6if needed and/or desired. The first protruding portion64P can be arranged to protrude radially outwardly from the first coupling portion74towards the second rotatable member66with respect to the rotational axis A6if needed and/or desired. The first protruding portion64P can be provided radially outwardly of the first contact surface74A if needed and/or desired. The first protruding portion64P can have a shape other than the annular shape if needed and/or desired.

In the present embodiment, the first protruding portion64P is integrally provided with the first coupling portion74and the first gear G7. However, the first protruding portion64P can be a separate member from at least one of the first coupling portion74and the first gear G7if needed and/or desired.

The hole64H includes a first hole64H1and a second hole64H2. The first coupling portion74defines the first hole64H1. The first protruding portion64P defines the second hole64H2. The first hole64H1has a first inner diameter DM31. The second hole64H2has a second inner diameter DM32. The second inner diameter DM32is smaller than the first inner diameter DM31. However, the second inner diameter DM32can be larger than or equal to the first inner diameter DM31if needed and/or desired.

The second gear G8is at least partially provided in the hole64H. The second gear G8is at least partially provided in the second hole64H2. In the present embodiment, the second gear G8is partially provided in the hole64H. The second gear G8is partially provided in the second hole64H2. However, the second gear G8can be entirely provided in the hole64H if needed and/or desired. The second gear G8can be entirely provided in at least one of the first hole64H1and the second hole64H2if needed and/or desired.

As seen inFIG.11, the first coupling portion74includes a first contact surface74A contactable with the resisting structure68. The second coupling portion76includes a second contact surface76A contactable with the resisting structure68. The first contact surface74A at least partially defines the hole64H. The first contact surface74A at least partially defines the first hole64H1. The first contact surface74A circumferentially extends about the rotational axis A6. The second contact surface76A circumferentially extends about the rotational axis A6. The first contact surface74A radially faces toward the second contact surface76A. The second contact surface76A radially faces toward the first contact surface74A.

The first contact surface74A is radially spaced apart from the second contact surface76A with respect to the rotational axis A6. In the present embodiment, the first contact surface74A is provided radially outwardly of the second contact surface76A with respect to the rotational axis A6. However, the first contact surface74A can be provided radially inwardly of the second contact surface76A with respect to the rotational axis A6if needed and/or desired.

As seen inFIG.10, the second rotatable member66includes a second protruding portion66P. The second protruding portion66P is provided radially closer to the first rotatable member64than the second coupling portion76with respect to the rotational axis A6. The second protruding portion66P protrudes radially from the second coupling portion76towards the first rotatable member64with respect to the rotational axis A6.

In the present embodiment, the second protruding portion66P is provided radially inwardly closer to the first rotatable member64than the second coupling portion76with respect to the rotational axis A6. The second protruding portion66P is provided radially inwardly closer to the first coupling portion74than the second coupling portion76with respect to the rotational axis A6. The second protruding portion66P protrudes radially inwardly from the second coupling portion76towards the first rotatable member64with respect to the rotational axis A6. The second protruding portion66P protrudes radially inwardly from the second coupling portion76towards the first coupling portion74with respect to the rotational axis A6. The second protruding portion66P is provided radially inwardly of the second contact surface76A. The second protruding portion66P has an annular shape.

However, the second protruding portion66P is provided radially outwardly closer to the first rotatable member64than the second coupling portion76with respect to the rotational axis A6if needed and/or desired. The second protruding portion66P can be arranged to protrude radially outwardly from the second coupling portion76towards the first rotatable member64with respect to the rotational axis A6if needed and/or desired. The second protruding portion66P can be provided radially outwardly of the second contact surface76A if needed and/or desired. The second protruding portion66P can have any shape other than the annular shape if needed and/or desired.

A first distance DS3is defined radially between the first protruding portion64P and the second gear G8. A second distance DS4is defined radially between the second protruding portion66P and the first coupling portion74. A third distance DS5is defined radially between the first coupling portion74and the second coupling portion76. In the present embodiment, each of the first distance DS3and the second distance DS4is shorter than the third distance DS5. However, at least one of the first distance DS3and the second distance DS4can be longer than or equal to the third distance DS5if needed and/or desired. The first protruding portion64P can be omitted from the first rotatable member64if needed and/or desired. The second protruding portion66P can be omitted from the second rotatable member66if needed and/or desired. At least one of the first distance DS3and the second distance DS4can be zero.

As seen inFIG.13, the first protruding portion64P at least partially overlaps the resisting structure68as viewed along the rotational axis A6. In the present embodiment, the first protruding portion64P entirely overlaps the resisting structure68as viewed along the rotational axis A6. However, the first protruding portion64P can be arranged to partially overlap the resisting structure68as viewed along the rotational axis A6if needed and/or desired.

As seen inFIG.14, the second protruding portion66P at least partially overlaps the resisting structure68as viewed along the rotational axis A6. In the present embodiment, the second protruding portion66P partially overlaps the resisting structure68as viewed along the rotational axis A6. However, the second protruding portion66P can be arranged to entirely overlap the resisting structure68as viewed along the rotational axis A6if needed and/or desired.

As seen inFIG.15, the second rotatable member66includes a first axial end66A and a second axial end66B. The second rotatable member66extends between the first axial end66A and the second axial end66B along the rotational axis A6. The second gear G8and the second coupling portion76are provided between the first axial end66A and the second axial end66B.

At least one of the first axial end66A and the second axial end66B is rotatably supported by the housing38about the rotational axis A6. Each of the first axial end66A and the second axial end66B is rotatably supported by the housing38about the rotational axis A6.

The bicycle motor unit32includes a first bearing BR1and a second bearing BR2. The housing38includes a third housing78. The third housing78is provided in the internal space38S. The third housing78is secured to the first housing50and the second housing52. The first bearing BR1is attached to the third housing78. The second bearing BR2is attached to the second housing52. The first bearing BR1rotatably supports the first axial end66A about the rotational axis A6. The second bearing BR2rotatably supports the second axial end66B about the rotational axis A6.

In the present embodiment, the first bearing BR1includes a sleeve. The second bearing BR2includes a sleeve. However, the structure of each of the first bearing BR1and the second bearing BR2is not limited to the illustrated embodiment.

As seen inFIG.10, the resisting structure68allows relative rotation between the first rotatable member64and the second rotatable member66in response to input of a predetermined rotational force RF1and/or RF2transmitted from at least one of the first rotatable member64and the second rotatable member66. In the present embodiment, the resisting structure68allows relative rotation between the first rotatable member64and the second rotatable member66in response to the input of the predetermined rotational force RF 1 transmitted from the first rotatable member64. The resisting structure68allows relative rotation between the first rotatable member64and the second rotatable member66in response to the input of the predetermined rotational force RF2transmitted from the first rotatable member64. The resisting structure68allows relative rotation between the first rotatable member64and the second rotatable member66in response to the input of the predetermined rotational force RF1transmitted from the first rotatable member64and/or the input of the predetermined rotational force RF2transmitted from the first rotatable member64.

The predetermined rotational force RF1is a rotational force greater than a rotational force threshold TR. The predetermined rotational force RF2is a rotational force greater than the rotational force threshold TR. Thus, the resisting structure68allows the relative rotation between the first rotatable member64and the second rotatable member66in a case where an input rotational force RF3applied to at least one of the first rotatable member64and the second rotatable member66is greater than the rotational force threshold TR.

As seen inFIG.11, a first frictional force FF1is applied between the first rotatable member64and the resisting structure68. The first frictional force FF1is applied to the first contact surface74A. The first contact surface74A has a first radius R1defined from the rotational axis A6. The rotational force threshold TR can be defined as the product obtained by multiplying the first frictional force FF1by the first radius R1.

A second frictional force FF2is applied between the second rotatable member66and the resisting structure68. The second frictional force FF2is applied to the second contact surface76A. The second contact surface76A has a second radius R2defined from the rotational axis A6. The rotational force threshold TR can be defined as the product obtained by multiplying the second frictional force FF2by the second radius R2.

As seen inFIG.10, the resisting structure68allows the relative rotation between the first rotatable member64and the second rotatable member66in response to the input of the predetermined rotational force RF1transmitted from the first rotatable member64. The resisting structure68allows the relative rotation between the first rotatable member64and the second rotatable member66in a case where an input rotational force RF31applied to the first rotatable member64is greater than the rotational force threshold TR. In the present embodiment, the slidable member72slides with at least one of the first contact surface74A and the second contact surface76A in response to the input of the predetermined rotational force RF1transmitted from the first rotatable member64. Thus, the first rotatable member64rotates relative to the second rotatable member66in a case where the input rotational force RF31applied to the first rotatable member64is greater than the rotational force threshold TR.

The second rotatable member66transmits an output rotational force RF41to the gear G9while the slidable member72is sliding with at least one of the first contact surface74A and the second contact surface76A in response to the input of the predetermined rotational force RF1transmitted from the first rotatable member64. The output rotational force RF41is less than or equal to the predetermined rotational force RF1. Namely, the output rotational force RF41is less than or equal to the rotational force threshold TR. Thus, the resisting structure68reduces the predetermined rotational force RF1to the output rotational force RF41when the predetermined rotational force RF1is applied to the first rotatable member64.

The resisting structure68restricts the relative rotation between the first rotatable member64and the second rotatable member66in a case where the input rotational force RF31applied to the first rotatable member64is less than or equal to the rotational force threshold TR. In the present embodiment, the slidable member72does not slide with at least one of the first contact surface74A and the second contact surface76A in a case where the input rotational force RF31applied to the first rotatable member64is less than or equal to the rotational force threshold TR. Thus, the second rotatable member66transmits an output rotational force RF51, which is equal to the input rotational force RF31, to the gear G9in a case where the input rotational force RF31is less than or equal to the rotational force threshold TR.

As seen inFIG.11, the resisting structure68allows the relative rotation between the first rotatable member64and the second rotatable member66in response to the input of the predetermined rotational force RF2transmitted from the first rotatable member64. The resisting structure68allows the relative rotation between the first rotatable member64and the second rotatable member66in a case where an input rotational force RF32applied to the first rotatable member64is greater than the rotational force threshold TR. In the present embodiment, the slidable member72slides with at least one of the first contact surface74A and the second contact surface76A in response to the input of the predetermined rotational force RF2transmitted from the first rotatable member64. Thus, the first rotatable member64rotates relative to the second rotatable member66in a case where the input rotational force RF32applied to the first rotatable member64is greater than the rotational force threshold TR.

The first rotatable member64transmits an output rotational force RF42to the gear G6while the slidable member72is sliding with at least one of the first contact surface74A and the second contact surface76A in response to the input of the predetermined rotational force RF2transmitted from the second rotatable member66. The output rotational force RF42is less than or equal to the predetermined rotational force RF2. Namely, the output rotational force RF42is less than or equal to the rotational force threshold TR. Thus, the resisting structure68reduces the predetermined rotational force RF2to the output rotational force RF42when the predetermined rotational force RF2is applied to the first rotatable member64.

The resisting structure68restricts the relative rotation between the first rotatable member64and the second rotatable member66in a case where the input rotational force RF32applied to the second rotatable member66is less than or equal to the rotational force threshold TR. In the present embodiment, the slidable member72does not slide with at least one of the first contact surface74A and the second contact surface76A in a case where the input rotational force RF32applied to the first rotatable member64is less than or equal to the rotational force threshold TR. Thus, the second rotatable member66transmits an output rotational force RF52, which is equal to the input rotational force RF32, to the gear G6in a case where the input rotational force RF32is less than or equal to the rotational force threshold TR.

As seen inFIG.7, the additional transmitting structure62has a transmitting-structure rotational axis A7. In the present embodiment, the rotational axis A6is not coincident with the transmitting-structure rotational axis A7. The rotational axis A6is offset from the transmitting-structure rotational axis A7. The rotational axis A6is parallel to the transmitting-structure rotational axis A7. However, the rotational axis A6can be non-parallel to the transmitting-structure rotational axis A7if needed and/or desired. The rotational axis A6can be coincide with the transmitting-structure rotational axis A7if needed and/or desired.

As seen inFIG.16, the additional transmitting structure62includes a first race80and a second race81. The first race80is secured to the housing38. The second race81extends along the transmitting-structure rotational axis A7. The second race81is rotatable relative to the first race80about the transmitting-structure rotational axis A7. The first race80is at least partially provided radially outwardly of the second race81. The second race81is at least partially provided radially inwardly of the first race80.

The first race80includes an outer race83having an annular shape. The second race81includes an inner race81A. The inner race81A is at least partially provided radially inwardly of the outer race83. The first race80includes a hole80H. The second race81extends through the hole80H along the transmitting-structure rotational axis A7. The second race81includes a rod part81B. The rod part81B extends from the inner race81A along the transmitting-structure rotational axis A7. The rod part81B extends through the hole80H of the first race80along the transmitting-structure rotational axis A7.

The additional transmitting structure62includes a first intermediate element84. The first intermediate element84is at least partially provided between the first race80and the second race81. In the present embodiment, the first intermediate element84is entirely provided between the first race80and the second race81. However, the first intermediate element84can be partially provided between the first race80and the second race81if needed and/or desired.

As seen inFIG.17, the first intermediate element84includes a first rotatable part84A and a second rotatable part84B. In the present embodiment, the first intermediate element84includes at least two first rotatable parts84A and at least two second rotatable parts84B. A total number of the first rotatable parts84A is six. A total number of the second rotatable parts84B is six. The first rotatable part84A has a columnar shape. The second rotatable part84B has a columnar shape.

However, the total number of the first rotatable parts84A is not limited to six. The total number of the second rotatable parts84B is not limited to six. The structure of the first intermediate element84is not limited to the first rotatable part84A and the second rotatable part84B. One of the first rotatable part84A and the second rotatable part84B can be omitted from the first intermediate element84if needed and/or desired. The first rotatable part84A can have shapes other than the columnar shape if needed and/or desired. The second rotatable part84B can have shapes other than the columnar shape if needed and/or desired.

The first rotatable part84A is at least partially provided between the first race80and the second race81. The second rotatable part84B is at least partially provided between the first race80and the second race81. In the present embodiment, the first rotatable part84A is entirely provided between the first race80and the second race81. The second rotatable part84B is entirely provided between the first race80and the second race81. However, the first rotatable part84A can be partially provided between the first race80and the second race81if needed and/or desired. The second rotatable part84B can be partially provided between the first race80and the second race81if needed and/or desired.

The first rotatable parts84A and the second rotatable parts84B are alternatingly arranged in a circumferential direction D3about the transmitting-structure rotational axis A7. The first rotatable parts84A and the second rotatable parts84B are spaced apart from each other in the circumferential direction D3.

The first race80includes an inner peripheral surface80A. The second race81includes at least two contact surfaces81C. A total number of the contact surfaces81C is six. The contact surface81C includes a flat surface. However, the total number of contact surfaces81C is not limited to six. The contact surface81C can have shapes other than the flat surface if needed and/or desired.

The first rotatable part84A and the second rotatable part84B are provided between the inner peripheral surface80A of the first race80and the contact surface81C of the second race81. The first rotatable part84A and the second rotatable part84B are contactable with the inner peripheral surface80A of the first race80and the contact surface81C of the second race81.

The first intermediate element84includes at least one intermediate-member group84G consisting of the first rotatable part84A and the second rotatable part84B. In the present embodiment, the first intermediate element84includes six intermediate-member groups84G each consisting of the first rotatable part84A and the second rotatable part84B. The intermediate-member group84G is at least partially provided between the inner peripheral surface80A of the first race80and the contact surface81C of the second race81. The intermediate-member group84G is spaced apart from each other in the circumferential direction D3. The intermediate-member groups84G respectively correspond to the contact surfaces81C of the second race81. However, a total number of the intermediate-member groups84G consisting of the first rotatable part84A and the second rotatable part84B is not limited to six.

The additional transmitting structure62includes at least one biasing element85. The biasing element85is configured to bias the first rotatable part84A and the second rotatable part84B to move away from each other. In the present embodiment, the additional transmitting structure62includes at least two biasing elements85. The biasing element85is provided between the first rotatable part84A and the second rotatable part84B of the intermediate-member group84G to bias the first rotatable part84A and the second rotatable part84B to move away from each other. A total number of the biasing elements85is six. The biasing element85includes a spring such as a coiled spring and a leaf spring. However, the biasing element85can include members other than the spring (e.g., an elastic member such as rubber) if needed and/or desired. The total number of the biasing elements85is not limited to six.

The contact surface81C of the second race81includes a first circumferential end81C1and a second circumferential end81C2. The contact surface81C extends between the first circumferential end81C1and the second circumferential end81C2. The first circumferential end81C1is closer to the first rotatable part84A than the second circumferential end81C2. The second circumferential end81C2is closer to the second rotatable part84B than the first circumferential end81C1.

A first radial distance DS1is radially defined between the inner peripheral surface80A of the first race80and the first circumferential end81C1of the contact surface81C of the second race81. A second radial distance DS2is radially defined between the inner peripheral surface80A of the first race80and the second circumferential end81C2of the contact surface81C of the second race81. The first rotatable part84A has a first diameter DM1. The second rotatable part84B has a second diameter DM2. The first radial distance DS1is shorter than the first diameter DM1. The second radial distance DS2is shorter than the second diameter DM2.

The biasing element85biases the first rotatable part84A to keep the first rotatable part84A in contact with the inner peripheral surface80A of the first race80and the contact surface81C of the second race81because of the biasing force of the biasing element85. The biasing element85biases the second rotatable part84B to keep the second rotatable part84B in contact with the inner peripheral surface80A of the first race80and the contact surface81C of the second race81because of the biasing force of the biasing element85.

As seen inFIG.18, the additional transmitting structure62includes a second intermediate element86. The second intermediate element86is at least partially provided between the first race80and the second race81. In the present embodiment, the second intermediate element86is partially provided between the first race80and the second race81. However, the second intermediate element86can be entirely provided between the first race80and the second race81.

The second intermediate element86is rotatable relative to the first race80about the transmitting-structure rotational axis A7. The second intermediate element86includes a shaft88. The shaft88extends along the transmitting-structure rotational axis A7. The second race81includes a support hole81H. The shaft88is rotatably provided in the support hole81H.

The second intermediate element86includes a coupling member90. The coupling member90is secured to the shaft88. The coupling member90is a separate member from the shaft88. However, the coupling member90can be integrally provided with the shaft88as a one-piece unitary member if needed and/or desired.

The coupling member90includes a base part92, at least two intermediate parts94, and at least two transmitting parts96. The base part92is secured to the shaft88. The base part92extends radially outwardly from the shaft88. The intermediate part94extends from the base part92along the transmitting-structure rotational axis A7. The intermediate part94is at least partially provided between the first race80and the second race81. The second race81includes at least two transmitting holes81D. The transmitting part96is provided in the transmitting hole81D of the second race81. The transmitting part96is contactable with the second race81to transmit rotation between the second race81and the second intermediate element86about the transmitting-structure rotational axis A7.

As seen inFIG.17, a total number of the intermediate parts94is six. A total number of the transmitting parts96is six. A total number of the transmitting hole81D is six. However, the total number of the intermediate parts94is not limited to six. The total number of the transmitting parts96is not limited to six. The total number of the transmitting hole81D is not limited to six.

The intermediate part94is at least partially provided between two adjacent groups of the intermediate-member groups84G in the circumferential direction D3. The intermediate part94is at least partially provided between the first rotatable part84A of one of the intermediate-member groups84G and the second rotatable part84B of another of the intermediate-member groups84G in the circumferential direction D3.

In the present embodiment, the base part92, the at least two intermediate parts94, and the at least two transmitting parts96are integrally provided with each other as a one-piece unitary member. However, at least one of the base part92, the at least two intermediate parts94, and the at least two transmitting parts96can be a separate member from another of the base part92, the at least two intermediate parts94, and the at least two transmitting parts96if needed and/or desired.

As seen inFIG.19, the second intermediate element86is rotatable relative to the second race81about the transmitting-structure rotational axis A7from a neutral position P20to a first rotational position P21in a first circumferential direction D21. As seen inFIG.20, the second intermediate element86is rotatable relative to the second race81about the transmitting-structure rotational axis A7from the neutral position P20to a second rotational position P22in a second circumferential direction D22different from the first circumferential direction D21. In the present embodiment, the second circumferential direction D22is an opposite direction of the first circumferential direction D21. However, the second circumferential direction D22can be a direction different from the opposite direction of the first circumferential direction D21.

As seen inFIGS.17,19, and20, the transmitting part96is contactable with an inner peripheral surface of the transmitting hole81D. As seen inFIG.17, the transmitting part96is spaced apart from the inner peripheral surface of the transmitting hole81D in an initial state where the second intermediate element86is in the neutral position P20. As seen inFIG.19, the transmitting part96is in contact with the inner peripheral surface of the transmitting hole81D in a first rotation state where the second intermediate element86is in the first rotational position P21. As seen inFIG.20, the transmitting part96is in contact with the inner peripheral surface of the transmitting hole81D in a second rotation state where the second intermediate element86is in the second rotational position P22.

As seen inFIGS.17,19, and20, the intermediate part94is contactable with each of the first rotatable part84A and the second rotatable part84B. As seen inFIG.17, the intermediate part94is spaced apart from each of the first rotatable part84A and the second rotatable part84B in the initial state where the second intermediate element86is in the neutral position P20. As seen inFIG.19, the intermediate part94is in contact with the first rotatable part84A in the first rotation state where the second intermediate element86is in the first rotational position P21. As seen inFIG.20, the intermediate part94is in contact with the second rotatable part84B in the second rotation state where the second intermediate element86is in the second rotational position P22.

As seen inFIG.17, the first intermediate element84is configured to restrict the second race81from rotating relative to the first race80in the first circumferential direction D21with respect to the transmitting-structure rotational axis A7when the second race81receives a first rotational force F11in the first circumferential direction D21. The first intermediate element84is configured to restrict the second race81from rotating relative to the first race80in the second circumferential direction D22with respect to the transmitting-structure rotational axis A7when the second race81receives a second rotational force F12in the second circumferential direction D22.

The first intermediate element84is configured to move toward the first race80in response to the first intermediate element84pushed by the second race81in the first circumferential direction D21with respect to the transmitting-structure rotational axis A7. The first intermediate element84is configured to move toward the first race80in response to the first intermediate element84pushed by the second race81in the second circumferential direction D22different from the first circumferential direction D21. The first intermediate element84is configured to rotate together with the first race80in a state where the second race81pushes the first intermediate element84without the second intermediate element86pushing the first intermediate element84. Since the first race80is secured to the housing38of the bicycle motor unit32, the first race80and the first intermediate element84are stationary relative to the housing38(see e.g.,FIG.17) in the state where the second race81pushes the first intermediate element84without the second intermediate element86pushing the first intermediate element84.

The first rotatable part84A is configured to restrict the second race81from rotating relative to the first race80in the first circumferential direction D21with respect to the transmitting-structure rotational axis A7when the second race81receives the first rotational force F11in the first circumferential direction D21. The second rotatable part84B is configured to restrict the second race81from rotating relative to the first race80in the second circumferential direction D22with respect to the transmitting-structure rotational axis A7when the second race81receives the second rotational force F12in the second circumferential direction D22.

As seen inFIG.17, the contact surface81C of the second race81is configured to press the first rotatable part84A against the inner peripheral surface80A of the first race80when the second race81receives the first rotational force F11in the first circumferential direction D21. The first race80and the second race81are locked by the first rotatable parts84A when the second race81receives the first rotational force F11in the first circumferential direction D21. The first rotatable parts84A is configured to restrict the second race81from rotating relative to the first race80in the first circumferential direction D21about the transmitting-structure rotational axis A7when the second race81receives the first rotational force F11in the first circumferential direction D21. Thus, the first race80secured to the housing38(see e.g.,FIG.16) receives the first rotational force F11transmitted to the second race81.

The contact surface81C of the second race81is configured to press the second rotatable part84B against the inner peripheral surface80A of the first race80when the second race81receives the second rotational force F12in the second circumferential direction D22. The first race80and the second race81are locked by the second rotatable parts84B when the second race81receives the second rotational force F12in the second circumferential direction D22. The second rotatable parts84B is configured to restrict the second race81from rotating relative to the first race80in the second circumferential direction D22about the transmitting-structure rotational axis A7when the second race81receives the second rotational force F12in the second circumferential direction D22. Thus, the first race80secured to the housing38(see e.g.,FIG.16) receives the second rotational force F12transmitted to the second race81.

The contact surface81C of the second race81is configured not to press the first rotatable part84A against the inner peripheral surface80A of the first race80when the second race81receives the second rotational force F12in the second circumferential direction D22. The first rotatable parts84A is configured not to restrict the second race81from rotating relative to the first race80in the second circumferential direction D22about the transmitting-structure rotational axis A7when the second race81receives the second rotational force F12in the second circumferential direction D22.

The contact surface81C of the second race81is configured not to press the second rotatable part84B against the inner peripheral surface80A of the first race80when the second race81receives the first rotational force F11in the first circumferential direction D21. The second rotatable parts84B is configured to restrict the second race81from rotating relative to the first race80in the first circumferential direction D21about the transmitting-structure rotational axis A7when the second race81receives the first rotational force F11in the first circumferential direction D21.

As seen inFIG.19, the first intermediate element84is configured to move away from the first race80in response to the first intermediate element84pushed by the second intermediate element86in the first circumferential direction D21. The first intermediate element84is configured to rotate relative to the first race80in a state where the second intermediate element86pushes the first intermediate element84without the second race81pushing the first intermediate element84. The first intermediate element84is configured to move radially inwardly with respect to the transmitting-structure rotational axis A7in response to the first intermediate element84pushed by the second intermediate element86in the first circumferential direction D21.

The second intermediate element86is configured to move the first intermediate element84relative to the second race81in the first circumferential direction D21to allow the second race81to rotate relative to the first race80in the first circumferential direction D21along with the second intermediate element86when the second intermediate element86receives a first rotational force F21in the first circumferential direction D21. The first intermediate element84is configured to rotate relative to the first race80together with the second race81and the second intermediate element86about the transmitting-structure rotational axis A7in the first circumferential direction D21when the second intermediate element86receives the first rotational force F21in the first circumferential direction D21.

The intermediate part94of the second intermediate element86is configured to move the first rotatable part84A relative to the second race81in the first circumferential direction D21in response to a first rotation of the second intermediate element86from the neutral position P20to the first rotational position P21in the first circumferential direction D21. The transmitting part96of the second intermediate element86is configured to rotate the second race81relative to the first race80in the first circumferential direction D21in response to the first rotation of the second intermediate element86from the first rotational position P21in the first circumferential direction D21. The second race81, the first intermediate element84, and the second intermediate element86rotate relative to the first race80in the first circumferential direction D21when the second intermediate element86receives the first rotational force F21in the first circumferential direction D21.

As seen inFIG.20, the first intermediate element84is configured to move away from the first race80in response to the first intermediate element84pushed by the second intermediate element86in the second circumferential direction D22different from the first circumferential direction D21. The first intermediate element84is configured to rotate relative to the first race80in a state where the second intermediate element86pushes the first intermediate element84without the second race81pushing the first intermediate element84. The first intermediate element84is configured to move radially inwardly with respect to the transmitting-structure rotational axis A7in response to the first intermediate element84pushed by the second intermediate element86in the second circumferential direction D22.

The second intermediate element86is configured to move the first intermediate element84relative to the second race81in the second circumferential direction D22to allow the second race81to rotate relative to the first race80in the second circumferential direction D22along with the second intermediate element86when the second intermediate element86receives a second rotational force F22in the second circumferential direction D22. The first intermediate element84is configured to rotate relative to the first race80together with the second race81and the second intermediate element86about the transmitting-structure rotational axis A7in the second circumferential direction D22when the second intermediate element86receives the second rotational force F22in the second circumferential direction D22.

The intermediate part94of the second intermediate element86is configured to move the second rotatable part84B relative to the second race81in the second circumferential direction D22in response to a second rotation of the second intermediate element86from the neutral position P20to the second rotational position P22in the second circumferential direction D22. The transmitting part96of the second intermediate element86is configured to rotate the second race81relative to the first race80in the second circumferential direction D22in response to the second rotation of the second intermediate element86from the second rotational position P22in the second circumferential direction D22. The second race81, the first intermediate element84, and the second intermediate element86rotate relative to the first race80in the second circumferential direction D22when the second intermediate element86receives the second rotational force F22in the second circumferential direction D22.

As seen inFIGS.7,19, and20, the additional transmitting structure62is configured to transmit a rotational force in multiple rotational directions based on a rotational direction of the output shaft33A in a state where the additional transmitting structure62transmits the rotational force. The multiple rotational directions are defined about the transmitting-structure rotational axis A7. The multiple rotational directions include the first circumferential direction D21and the second circumferential direction D22. The additional transmitting structure62is configured to transmit the first rotational force F21in the first circumferential direction D21based on a first rotational direction D31of the output shaft33A in the state where the additional transmitting structure62transmits the first rotational force F21. The additional transmitting structure62is configured to transmit the first rotational force F21in the second circumferential direction D22based on a second rotational direction D32of the output shaft33A in the state where the additional transmitting structure62transmits the first rotational force F21. The second rotational direction D32is an opposite direction of the first rotational direction D31.

As seen inFIG.21, the driving rotational force RF0is transmitted from the electric motor33to the additional transmitting structure62. The driving rotational force RF0is transmitted from the electric motor33to the transmitting structure60via the additional transmitting structure62since the driving rotational force RF0integrally rotates the second intermediate element86and the second race81(see e.g.,FIGS.19and20).

The driving rotational force RF0is set to be less than or equal to the rotational force threshold TR. Thus, the driving rotational force RF0is transmitted, as the output rotational force RF51, from the electric motor33to the output member56via the additional transmitting structure62and the transmitting structure60without being reduced by the transmitting structure60. Accordingly, the chain guide14is moved in response to the driving rotational force RF0transmitted from the bicycle motor unit32.

The external rotational force ERF is applied to the output member56when the external force EF is applied to at least one of the chain guide14and the linkage16. The external rotational force ERF is transmitted from the output member56to the second rotatable member66of the transmitting structure60as the input rotational force RF32.

The external rotational force ERF is transmitted, as the output rotational force RF52, from the transmitting structure60to the additional transmitting structure62without being reduced by the transmitting structure60in a case where the external rotational force ERF is less than or equal to the rotational force threshold TR.

The external rotational force ERF is transmitted, as the output rotational force RF42, from the transmitting structure60to the additional transmitting structure62in a case where the external rotational force ERF is greater than the rotational force threshold TR. The external rotational force ERF is reduced to the output rotational force RF42by the relative rotation between the first rotatable member64and the second rotatable member66(see e.g.,FIG.10) of the transmitting structure60.

However, neither the output rotational force RF52nor RF42is transmitted from the additional transmitting structure62to the electric motor33since the first intermediate element84(see e.g.,FIG.17) restricts the second race81from rotating relative to the first race80. Since the first race80(see e.g.,FIG.17) is secured to the housing38, the first race80and the second race81are not rotated relative to the housing38by the output rotational force RF52or RF42. Thus, the external rotational force ERF is blocked by the additional transmitting structure62and is not transmitted to the electric motor33.

As seen inFIG.15, the bicycle motor unit32further comprises a detection object100. The bicycle motor unit32comprises a detector102configured to detect the detection object100. The detection object100is configured to be detected by the detector102. The detector102is configured to detect a position of the detection object100. The detection object100is coupled to the second rotatable member66to rotate along with the second rotatable member66about the rotational axis A6. The detector102is configured to detect a rotational position of the detection object100. Thus, the detector102is configured to detect a rotational position of the second rotatable member66of the transmitting structure60. The rotational position of the second rotatable member66corresponds to a position of the chain guide14and a gear position of the bicycle derailleur RD. Thus, the detector102is configured to detect the position of the chain guide14and the gear position of the bicycle derailleur RD.

In the present embodiment, the detector102includes a non-contact detector such as an angle sensor and an encoder. Examples of the angle sensor include a magneto-resistive sensor. Examples of the encoder include a magnetic sensor (e.g., a hall sensor) and an optical sensor (e.g., a photo sensor). The detection object100includes a magnetic body (e.g., magnet) and a light emitter (e.g., a light emitting diode (LED)). However, the detector102can include a contact detector if needed and/or desired. The detection object100can include parts other than the magnetic body or the light emitter.

The bicycle motor unit32includes a calculation circuit103. The calculation circuit103is electrically connected to the detector102to calculate a rotational angle of the detection object100based on a detection result of the detector100. For example, the calculation circuit103is configured to calculate an absolute rotational angle of the detection object100based on the detection result of the detector100.

As seen inFIG.7, the detection object100is provided on a downstream side with respect to the additional transmitting structure62on the power transmission path TP. The detection object100is provided on a downstream side with respect to the transmitting structure60on the power transmission path TP. The detection object100is provided on the downstream side with respect to the transmitting structure60on the power transmission path TP in the first power-transmission direction LD1. The detection object100is provided on the downstream side with respect to the additional transmitting structure62on the power transmission path TP in the first power-transmission direction LD1.

As seen inFIG.22, the bicycle motor unit32includes an electronic controller104, a motor driver106, a communicator108, an informing device110, and an electric switch SW. The electronic controller104is electrically connected to the detector102, the calculation circuit103, the motor driver106, the communicator108, and the informing device110. The power-supply attachment structure34is electrically connected to the detector102, the calculation circuit103, the electronic controller104, the motor driver106, the communicator108, and the informing device110. The electric power source36is electrically connected to the detector102, the calculation circuit103, the electronic controller104, the motor driver106, the communicator108, and the informing device110via the power-supply attachment structure34to supply electricity to the detector102, the calculation circuit103, the electronic controller104, the motor driver106, the communicator108, and the informing device110via the power-supply attachment structure34.

As seen inFIG.22, the electronic controller104includes a processor104P, a memory104M, a circuit board104C, and a bus104D. The processor104P and the memory104M are electrically mounted on the circuit board104C. The processor104P and the memory104M are electrically connected to the circuit board104C via the bus104D. The processor104P is electrically connected to the memory104M via the circuit board104C and the bus104D.

For example, the processor104P includes at least one of a central processing unit (CPU), a micro processing unit (MPU), and a memory controller. The memory104M is electrically connected to the processor104P. For example, the memory104M includes at least one of a volatile memory and a non-volatile memory. Examples of the volatile memory include a random-access memory (RAM) and a dynamic random-access memory (DRAM). Examples of the non-volatile memory include a read only memory (ROM), an electrically erasable programmable ROM (EEPROM), and a hard disc drive (HDD). The memory104M includes storage areas each having an address. The processor104P is configured to control the memory104M to store data in the storage areas of the memory104M and reads data from the storage areas of the memory104M. The processor104P can also be referred to as a hardware processor104P. The memory104M can also be referred to as a hardware memory104M. The memory104M can also be referred to as a computer-readable storage medium104M.

The electronic controller104is programed to execute at least one control algorithm of the bicycle derailleur RD. The memory104M (e.g., the ROM) stores at least one program including at least one program instruction. The at least one program is read into the processor104P, and thereby the at least one control algorithm of the bicycle derailleur RD is executed based on the at least one program. The electronic controller104can also be referred to as an electronic controller circuit or circuitry104. The electronic controller104can also be referred to as a hardware electronic controller104.

The structure of the electronic controller104is not limited to the above structure. The structure of the22is not limited to the processor104P, the memory104M, and the bus104D. The electronic controller104can be realized by hardware alone or a combination of hardware and software. The processor104P and the memory104M can be integrated as a one chip such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

The communicator108is configured to communicate with other devices such as the operating devices3and4and the bicycle derailleur FD. The communicator108includes a wireless communicator WC. The electronic controller104is electrically connected to the wireless communicator WC to control the wireless communicator WC. The electronic controller104is configured to control the wireless communicator WC to execute pairing between the wireless communicator WC and other wireless communicators of the operating devices3and4and the bicycle derailleur FD.

The wireless communicator WC is electrically connected to the processor104P and the memory104M with the circuit board104C and the bus104D. The wireless communicator WC includes a signal transmitting circuit or circuitry and a signal receiving circuit or circuitry. Thus, the wireless communicator WC can also be referred to as a wireless communicator circuit or circuitry WC.

The wireless communicator WC is configured to superimpose digital signals on carrier wave using a predetermined wireless communication protocol to wirelessly transmit signals. In the first embodiment, the wireless communicator WC is configured to encrypt signals using a cryptographic key to generate encrypted wireless signals. The wireless communicator WC includes at least one antenna. The wireless communicator WC is configured to transmit wireless signals via the at least one antenna. The wireless communicator WC can include at least two antennas. In a case where the wireless communicator WC includes at least two antennas, the wireless communicator WC can be configured to wirelessly communicate with another device of the bicycle2via one of the at least two antennas and to wirelessly communicate with a wireless device such as a smartphone, a tablet computer, and a personal computer via another of the at least two antennas.

The wireless communicator WC is configured to receive wireless signals via the antenna. In the first embodiment, the wireless communicator WC is configured to decode the wireless signals to recognize signals transmitted from other wireless communicators. The wireless communicator WC is configured to decrypt the wireless signals using the cryptographic key.

The operating device3is configured to generate a control signal in response to a user input. For example, the operating device3includes a first electric switch, a first additional electric switch, and a first communicator. The first electric switch is configured to receive a first user input. The first additional electric switch is configured to receive a first additional user input. The first communicator is configured to wirelessly transmit a control signal CS11in response to the first user input received by the first electric switch. The first communicator is configured to wirelessly transmit a control signal CS12in response to the first additional user input received by the first additional electric switch. For example, the control signal CS11indicates upshifting of the bicycle derailleur RD. The control signal CS12indicates downshifting of the bicycle derailleur RD. The operating device3can be configured to transmit control signals via an electric cable if needed and/or desired.

The operating device4is configured to generate a control signal in response to a user input. For example, the operating device4includes a second electric switch, a second additional electric switch, and a second communicator. The second electric switch is configured to receive a second user input. The second additional electric switch is configured to receive a second additional user input. The second communicator is configured to wirelessly transmit a control signal CS21in response to the second user input received by the second electric switch. The second communicator is configured to wirelessly transmit a control signal CS22in response to the second additional user input received by the second additional electric switch. For example, the control signal CS21indicates upshifting of the bicycle derailleur FD. The control signal CS22indicates downshifting of the bicycle derailleur FD. The operating device4can be configured to transmit control signals via an electric cable if needed and/or desired.

The wireless communicator WC is configured to wirelessly receive the control signals CS11, CS12, CS21, and CS22transmitted from the operating devices3and4. The electronic controller104is configured to receive the control signals CS11, CS12, CS21, and CS22wirelessly transmitted from the operating devices3and4via the wireless communicator WC. The wireless communicator WC is configured to wirelessly communicate with a wireless communicator of the bicycle derailleur FD. The wireless communicator WC is configured to wirelessly transmit, to the bicycle derailleur FD, the control signals CS21and CS22transmitted from the operating device4. The communicator108can include a wired communicator configured to communicate with another wired communicator via an electric cable if needed and/or desired.

The motor driver106is electrically connected to the electric motor33and the electronic controller104to control the electric motor33based on the control signals transmitted from the electronic controller104. The motor driver106is configured to control electricity supplied from the electric power source36based on the control signals CS11and CS12transmitted from the electronic controller104. Namely, the electronic controller104is configured to control the electric motor33based on the control signals CS11and CS12transmitted from the operating devices3and4.

The communicator108includes a wired communicator WD. The wired communicator WD is configured to communicate with another wired communicator of another device such as the derailleur FD via a wired communication structure WS including the electric cable EC. The wired communicator WD is electrically connected to the electronic controller104. The bicycle motor unit32is electrically connected to an external power source PS and the derailleur FD via the wired communication structure WS. The derailleurs RD2and FD are powered by the external power source PS.

As seen inFIG.23, the wired communicator WD is configured to communicate with another wired communicator of another device via the wired communication structure WS using power line communication (PLC) technology. For example, the wired communication structure WS includes a ground line and a voltage line that are detachably connected to a serial bus that is formed by communication interfaces. In the present embodiment, the wired communicator WD is configured to communicate with the derailleur FD through the voltage line using the PLC technology. Since the PLC technology has been known, it will not be described in detail here for the sake of brevity.

The electronic controller104is configured to control the wired communicator WD to transmit the control signal CS21to the derailleur FD via the wired communication structure WS in a case where the wireless communicator WC wirelessly receives the control signal CS21from the operating device4. The electronic controller104is configured to control the wired communicator WD to transmit the control signal CS22to the derailleur FD via the wired communication structure WS in a case where the wireless communicator WC wirelessly receives the control signal CS22from the operating device4.

The connection port12P is electrically connected to the electronic controller104via the wired communicator WD. Electricity can be supplied from the external power source PS to the bicycle motor unit32via the connection port12P and the wired communicator WD in a state where the external power source PS is connected to the connection port12P via the electric cable EC.

As seen inFIG.22, the informing device110is configured to inform the user of information relating to the bicycle derailleur RD. The informing device110includes an indicator configured to indicate the information. For example, the indicator includes a light emitting diode.

The electric switch SW is configured to receive a user input from the user. The electric switch SW is configured to be activated in response to the user input. The electric switch SW is electrically connected to the electronic controller104. The electronic controller104is configured to recognize the activation of the electric switch SW. The user input includes a normal press, a long press, and a double click of the electric switch SW.

The electronic controller104is electrically connected to the calculation circuit103to receive the rotational position calculated by the calculation circuit103. The electronic controller104is configured to monitor a current gear position of the bicycle derailleur RD based on the rotational position calculated by the calculation circuit103. The electronic controller104is configured to store the current gear position in the memory104M. The transmitting structure60allows the output member56to rotate in the state where the external rotational force ERF is equal to or higher than the external torque threshold. Thus, the chain guide14can be unintentionally moved by the external force EF caused by the physical contact between the obstacle and at least one of the chain guide14and the linkage16. The bicycle motor unit32is configured to automatically return the chain guide14to a previous gear position which is a position before the chain guide14is moved by the external force EF.

The electronic controller104is configured to periodically monitor the current gear position based on the rotational position calculated by the calculation circuit103. The electronic controller104is configured to periodically determine, based on the rotational position calculated by the calculation circuit103, whether the chain guide14is moved from the current gear position by the external force EF. The electronic controller104is configured to conclude that the chain guide14is moved from the current gear position by the external force EF if the rotational position calculated by the calculation circuit103indicates that the chain guide14is moved while the electronic controller104does not receive the control signals CS11and CS12generated by the operating device3.

If the electronic controller104concludes that the chain guide14is moved from the current gear position by the external force EF, the electronic controller104controls the electric motor33to return the chain guide14to the previous gear position. The electronic controller104is configured to control the informing device110to inform the user that the chain guide14is moved by the external force EF.

Second Embodiment

A bicycle motor unit232in accordance with a second embodiment will be described below referring toFIGS.24and25. The bicycle motor unit232has the same structure and/or configuration as those of the bicycle motor unit32except for the transmitting structure60. Thus, elements having substantially the same function as those in the first embodiment will be numbered the same here and will not be described and/or illustrated again in detail here for the sake of brevity.

As seen inFIG.24, the bicycle motor unit232comprises a transmitting structure260. The transmitting structure260has substantially the same structure as the structure of the transmitting structure60described in the first embodiment. The transmitting structure260includes a first rotatable member264, a second rotatable member266, and the resisting structure68. The first rotatable member264is rotatable about the rotational axis A6. The second rotatable member266is rotatable relative to the first rotatable member264about the rotational axis A6.

The first rotatable member264includes the first gear G7. The first gear G7is configured to mesh with the first additional gear G6to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33via the first additional gear G6. The second rotatable member266includes the second gear G8. The second gear G8is configured to mesh with the second additional gear G9to transmit the driving force (e.g., the driving rotational force RF0) to the second additional gear G9.

The resisting structure68is at least partially provided radially between the first rotatable member264and the second rotatable member266with respect to the rotational axis A6so as to resist relative rotation between the first rotatable member264and the second rotatable member266.

In the present embodiment, the resisting structure68is entirely provided radially between the first rotatable member264and the second rotatable member266with respect to the rotational axis A6so as to resist the relative rotation between the first rotatable member264and the second rotatable member266. However, the resisting structure68can be partially provided radially between the first rotatable member264and the second rotatable member266with respect to the rotational axis A6so as to resist the relative rotation between the first rotatable member264and the second rotatable member266if needed and/or desired.

The first rotatable member264is radially spaced apart from the second rotatable member266with respect to the rotational axis A6. The second rotatable member266is at least partially provided radially inwardly of the first rotatable member264with respect to the rotational axis A6. In the present embodiment, the second rotatable member266is partially provided radially inwardly of the first rotatable member264with respect to the rotational axis A6. However, the second rotatable member266can be entirely provided radially inwardly of the first rotatable member264with respect to the rotational axis A6if needed and/or desired. The first rotatable member264can be at least partially provided radially inwardly of the second rotatable member266with respect to the rotational axis A6if needed and/or desired.

The resisting member70is a separate member from at least one of the first rotatable member264and the second rotatable member266. In the present embodiment, the resisting member70is a separate member from the first rotatable member264and the second rotatable member266. However, the resisting member70can be integrally provided with one of the first rotatable member264and the second rotatable member266as a one-piece unitary member if needed and/or desired.

The slidable member72is configured to slidably contact at least one of the first rotatable member264and the second rotatable member266. The slidable member72circumferentially extends about the rotational axis A6. The slidable member72is radially deformed between the first rotatable member264and the second rotatable member266.

As seen inFIG.25, the slidable member72is configured to slidably contact both the first rotatable member264and the second rotatable member266. The base part72A slidably contacts the second rotatable member266. The at least two slidable parts72B slidably contacts the first rotatable member264. The base part72A circumferentially extends about the rotational axis A6. The at least two slidable parts72B protrude radially from the base part72A toward one of the first rotatable member264and the second rotatable member266. The at least two slidable parts72B protrude radially inwardly from the base part72A toward the first rotatable member264. However, the at least two slidable parts72B protrude radially from the base part72A toward the second rotatable member266if needed and/or desired. The base part72A can be configured to slidably contact the first rotatable member264if needed and/or desired. The at least two slidable parts72B can be configured to slidably contact the second rotatable member266if needed and/or desired.

As seen inFIG.24, the first rotatable member264includes a first coupling portion274coupled to the resisting structure68. The second rotatable member266includes a second coupling portion276coupled to the resisting structure68. The second coupling portion276is at least partially provided radially outwardly of the first coupling portion274. The first coupling portion274has a tubular shape. The second coupling portion276has a tubular shape. The first rotatable member264includes a hole264H. The hole264H extends along the rotational axis A6. The first coupling portion274includes the hole264H.

In the present embodiment, the second rotatable member266includes a radially inner portion275. The radially inner portion275is provided radially inwardly of the second coupling portion276with respect to the rotational axis A6. The first coupling portion274is at least partially provided radially between the second coupling portion276and the radially inner portion275with respect to the rotational axis A6.

The second rotatable member266is at least partially provided in the hole264H. The radially inner portion275extends from the second gear G8along the rotational axis A6. The radially inner portion275is at least partially provided in the hole264H. The first rotatable member264is slidable with the radially inner portion275. The first coupling portion274is slidable with the radially inner portion275. For example, grease can be provided between the first coupling portion274and the radially inner portion275.

The second rotatable member266includes a second hole266H. The second hole266H extends along the rotational axis A6. The second coupling portion276includes the second hole266H. The first coupling portion274is at least partially provided radially inwardly of the second coupling portion276. The first coupling portion274is at least partially provided in the second hole266H.

In the present embodiment, the first coupling portion274is partially provided radially inwardly of the second coupling portion276. The first coupling portion274is partially provided in the second hole266H. However, the first coupling portion274can be entirely provided radially inwardly of the second coupling portion276if needed and/or desired. The first coupling portion274can be entirely provided in the second hole266H if needed and/or desired. The second coupling portion276can be at least partially provided radially inwardly of the first coupling portion274if needed and/or desired.

The second rotatable member266includes a second extending portion277. The second extending portion277extends between the radially inner portion275and the second coupling portion276such that the second coupling portion276is rotatable integrally with the radially inner portion275about the rotational axis A6.

The second extending portion277extends radially from the second coupling portion276toward the radially inner portion275. The second extending portion277extends radially inwardly from the second coupling portion276toward the radially inner portion275. The second extending portion277is coupled to the radially inner portion275to rotate integrally with the radially inner portion275about the rotational axis A6. The second extending portion277is integrally provided with the second coupling portion276. Thus, the second coupling portion276and the second extending portion277are rotatable integrally with the radially inner portion275and the second gear G8about the rotational axis A6.

In the present embodiment, the second extending portion277is coupled to the radially inner portion275with a structure such as a serration or a spline. For example, the second extending portion277includes at least two first teeth277A. The radially inner portion275includes at least two second teeth275A. The at least two first teeth277A mesh with the at least two second teeth275A. However, the second extending portion277can be coupled to the radially inner portion275with structures other than a serration or a spline if needed and/or desired.

As seen inFIG.24, the first rotatable member264is operatively coupled to the electric motor33to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33. The second rotatable member266is configured to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33via the resisting structure68and the first rotatable member264. However, the second rotatable member266can be operatively coupled to the electric motor33to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33if needed and/or desired. The first rotatable member264is configured to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33via the resisting structure68and the second rotatable member266if needed and/or desired.

The first gear G7is coupled to the first coupling portion274. The first coupling portion274extends from the first gear G7along the rotational axis A6. The first gear G7protrudes radially from the first coupling portion274with respect to the rotational axis A6. The first gear G7protrudes radially outwardly from the first coupling portion274with respect to the rotational axis A6. In the present embodiment, the first gear G7is integrally provided with the first coupling portion274as a one-piece unitary member. However, the first gear G7can be a separate member from the first coupling portion274if needed and/or desired.

The second gear G8is coupled to the second coupling portion276. The second coupling portion276extends from the second gear G8along the rotational axis A6. The second gear G8extends from the second coupling portion276along the rotational axis A6. The second gear G8is at least partially provided in the hole264H. In the present embodiment, the second gear G8is entirely provided outside the hole264H. The second gear G8is a separate member from the second coupling portion276. However, the second gear G8can be partially provided outside the hole264H if needed and/or desired. The second gear G8can be integrally provided with the second coupling portion276as a one-piece unitary member if needed and/or desired.

As seen inFIG.25, the first coupling portion274includes a first contact surface274A contactable with the resisting structure68. The second coupling portion276includes a second contact surface276A contactable with the resisting structure68.

The first contact surface274A at least partially defines the hole264H. The first contact surface274A circumferentially extends about the rotational axis A6. The second contact surface276A circumferentially extends about the rotational axis A6. The first contact surface274A radially faces toward the second contact surface276A. The second contact surface276A radially faces toward the first contact surface274A.

The first contact surface274A is radially spaced apart from the second contact surface276A with respect to the rotational axis A6. In the present embodiment, the first contact surface274A is provided radially inwardly of the second contact surface276A with respect to the rotational axis A6. However, the first contact surface274A can be provided radially outwardly of the second contact surface276A with respect to the rotational axis A6if needed and/or desired.

The description regarding the bicycle motor unit32described in the first embodiment can be utilized as the description regarding the bicycle motor unit232. Thus, the bicycle motor unit232will not be described in detail here for the sake of brevity.

The first rotatable member264can be provided in the position depicted inFIG.26if needed and/or desired. In the modification depicted inFIG.26, the first coupling portion274is provided closer to the second gear G8than the first gear G7in an axial direction D6parallel to the rotational axis A6. The at least two first teeth277A mesh with teeth of the second gear G8. The at least two second teeth275A are omitted from the second rotatable member266.

Third Embodiment

A bicycle motor unit332in accordance with a second embodiment will be described below referring toFIGS.27and28. The bicycle motor unit332has the same structure and/or configuration as those of the bicycle motor unit32except for the transmitting structure60. Thus, elements having substantially the same function as those in the first or second embodiment will be numbered the same here and will not be described and/or illustrated again in detail here for the sake of brevity.

As seen inFIG.27, the bicycle motor unit332comprises a transmitting structure360. The transmitting structure360has substantially the same structure as the structure of the transmitting structure60described in the first embodiment. The transmitting structure360includes a first rotatable member364, the second rotatable member66, and the resisting structure68. The first rotatable member364is rotatable about the rotational axis A6. The second rotatable member66is rotatable relative to the first rotatable member364about the rotational axis A6. The first rotatable member364includes the first gear G7.

The resisting structure68is at least partially provided radially between the first rotatable member364and the second rotatable member66with respect to the rotational axis A6so as to resist relative rotation between the first rotatable member364and the second rotatable member66.

In the present embodiment, the resisting structure68is entirely provided radially between the first rotatable member364and the second rotatable member66with respect to the rotational axis A6so as to resist the relative rotation between the first rotatable member364and the second rotatable member66. However, the resisting structure68can be partially provided radially between the first rotatable member364and the second rotatable member66with respect to the rotational axis A6so as to resist the relative rotation between the first rotatable member364and the second rotatable member66if needed and/or desired.

The first rotatable member364is radially spaced apart from the second rotatable member66with respect to the rotational axis A6. The second rotatable member66is at least partially provided radially inwardly of the first rotatable member364with respect to the rotational axis A6. In the present embodiment, the second rotatable member66is partially provided radially inwardly of the first rotatable member364with respect to the rotational axis A6. However, the second rotatable member66can be entirely provided radially inwardly of the first rotatable member364with respect to the rotational axis A6if needed and/or desired. The first rotatable member364can be at least partially provided radially inwardly of the second rotatable member66with respect to the rotational axis A6if needed and/or desired.

The resisting member70is a separate member from at least one of the first rotatable member364and the second rotatable member66. In the present embodiment, the resisting member70is a separate member from the first rotatable member364and the second rotatable member66. However, the resisting member70can be integrally provided with one of the first rotatable member364and the second rotatable member66as a one-piece unitary member if needed and/or desired.

The slidable member72is configured to slidably contact at least one of the first rotatable member364and the second rotatable member66. The slidable member72circumferentially extends about the rotational axis A6. The slidable member72is radially deformed between the first rotatable member364and the second rotatable member66.

As seen inFIG.27, the slidable member72is configured to slidably contact both the first rotatable member364and the second rotatable member66. The base part72A slidably contacts the first rotatable member364. The at least two slidable parts72B slidably contacts the second rotatable member66. The base part72A circumferentially extends about the rotational axis A6. The at least two slidable parts72B protrude radially from the base part72A toward one of the first rotatable member364and the second rotatable member66. The at least two slidable parts72B protrude radially inwardly from the base part72A toward the second rotatable member66. However, the at least two slidable parts72B protrude radially outwardly from the base part72A toward the first rotatable member364if needed and/or desired. The base part72A can be configured to slidably contact the second rotatable member66if needed and/or desired. The at least two slidable parts72B can be configured to slidably contact the first rotatable member364if needed and/or desired.

As seen inFIG.27, the first rotatable member364includes a first coupling portion374coupled to the resisting structure68. The second rotatable member66includes the second coupling portion76coupled to the resisting structure68. The second coupling portion76is at least partially provided radially inwardly of the first coupling portion374. The first coupling portion374has a tubular shape. The first rotatable member364includes the hole64H. The hole64H extends along the rotational axis A6. The first coupling portion374includes the hole264H. The second coupling portion76is at least partially provided in the hole64H.

In the present embodiment, the second coupling portion76is entirely provided radially inwardly of the first coupling portion374. The second coupling portion76is entirely provided in the hole64H. However, the second coupling portion76can be partially provided radially inwardly of the first coupling portion374if needed and/or desired. The second coupling portion76can be partially provided in the hole64H if needed and/or desired. The first coupling portion374can be at least partially provided radially inwardly of the second coupling portion76if needed and/or desired.

As seen inFIG.27, the first rotatable member364is operatively coupled to the electric motor33to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33. The second rotatable member66is configured to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33via the resisting structure68and the first rotatable member364. However, the second rotatable member66can be operatively coupled to the electric motor33to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33if needed and/or desired. The first rotatable member364is configured to receive the driving force (e.g., the driving rotational force RF0) from the electric motor33via the resisting structure68and the second rotatable member66if needed and/or desired.

The first gear G7is coupled to the first coupling portion374. The first coupling portion374includes the first contact surface74A contactable with the resisting structure68. The first coupling portion374extends from the first gear G7along the rotational axis A6. The first gear G7protrudes radially from the first coupling portion374with respect to the rotational axis A6. The first gear G7protrudes radially outwardly from the first coupling portion374with respect to the rotational axis A6. In the present embodiment, the first gear G7is a separate member from the first coupling portion374. However, the first gear G7can be integrally provided with the first coupling portion374as a one-piece unitary member if needed and/or desired.

The first coupling portion374is a separate member from the first gear G7. The first coupling portion374includes a first engagement part374B. The first gear G7includes a second engagement part379. The second engagement part379includes an engagement recess379B. The first engagement part374B is at least partially provided in the engagement recess379B.

In the present embodiment, as seen inFIG.28, the first engagement part374B is coupled to the second engagement part379with a structure such as a serration or a spline. For example, the first engagement part374B includes at least two first engagement teeth374C. The second engagement part379includes at least two second engagement teeth379C at least partially defining the engagement recess379B. The at least two first engagement teeth374C mesh with the at least two second engagement teeth379C. Thus, the first coupling portion374rotates integrally with the first gear G7relative to the second rotatable member66about the rotational axis A6. The first engagement part374B can be coupled to the second engagement part379with another structure other than a serration or a spline if needed and/or desired.

As seen inFIG.27, the first rotatable member364includes the first protruding portion64P. The first protruding portion64P is provided radially closer to the second rotatable member66than the first coupling portion374with respect to the rotational axis A6. The first protruding portion64P protrudes radially from the first coupling portion374towards the second rotatable member66with respect to the rotational axis A6.

In the present embodiment, the first protruding portion64P is provided radially inwardly closer to the second rotatable member66than the first coupling portion374with respect to the rotational axis A6. The first protruding portion64P is provided radially inwardly closer to the second gear G8than the first coupling portion374with respect to the rotational axis A6. The first protruding portion64P protrudes radially inwardly from the first coupling portion374towards the second rotatable member66with respect to the rotational axis A6. The first protruding portion64P protrudes radially inwardly from the first coupling portion374towards the second gear G8with respect to the rotational axis A6. The first protruding portion64P has an annular shape.

However, the first protruding portion64P can have a shape other than the annular shape if needed and/or desired. The first protruding portion64P can be omitted from the first rotatable member364in the third embodiment if needed and/or desired.

The second protruding portion66P is provided radially closer to the first rotatable member364than the second coupling portion76with respect to the rotational axis A6. The second protruding portion66P protrudes radially from the second coupling portion76towards the first rotatable member364with respect to the rotational axis A6.

In the present embodiment, the second protruding portion66P is provided radially inwardly closer to the first rotatable member364than the second coupling portion76with respect to the rotational axis A6. The second protruding portion66P is provided radially inwardly closer to the first coupling portion374than the second coupling portion76with respect to the rotational axis A6. The second protruding portion66P protrudes radially outwardly from the second coupling portion76towards the first rotatable member364with respect to the rotational axis A6. The second protruding portion66P protrudes radially outwardly from the second coupling portion76towards the first coupling portion374with respect to the rotational axis A6. The second protruding portion66P is provided radially outwardly of the second contact surface76A. The second protruding portion66P has an annular shape.

However, the second protruding portion66P can have any shape other than the annular shape if needed and/or desired. The second protruding portion66P can be omitted from the second rotatable member66in the third embodiment if needed and/or desired.

A second distance DS34is defined radially between the second protruding portion66P and the first coupling portion374. A third distance DS35is defined radially between the first coupling portion374and the second coupling portion76. In the present embodiment, each of the first distance DS3and the second distance DS34is shorter than the third distance DS35. However, at least one of the first distance DS3and the second distance DS34can be longer than or equal to the third distance DS35if needed and/or desired. The first protruding portion64P can be omitted from the first rotatable member364if needed and/or desired. The second protruding portion66P can be omitted from the second rotatable member66if needed and/or desired.

As seen inFIG.28, the first protruding portion64P at least partially overlaps the resisting structure68as viewed along the rotational axis A6. In the present embodiment, the first protruding portion64P entirely overlaps the resisting structure68as viewed along the rotational axis A6. However, the first protruding portion64P can be arranged to partially overlap the resisting structure68as viewed along the rotational axis A6if needed and/or desired.

The bicycle motor unit32further comprises a restricting member367. The restricting member367is coupled to at least one of the first rotatable member364and the second rotatable member66to restrict a relative movement between the first rotatable member364and the second rotatable member66along the rotational axis A6.

In the present embodiment, the restricting member367is coupled to the second rotatable member66to restrict the relative movement between the first rotatable member364and the second rotatable member66along the rotational axis A6. The restricting member367is coupled to the second gear G8to restrict the relative movement between the first rotatable member364and the second rotatable member66along the rotational axis A6.

For example, the restricting member367has an annular shape. The restricting member367includes at least two teeth367A. The at least two teeth367A mesh with the teeth of the second gear G8. The at least two teeth367A mesh with the teeth of the second gear G8. The restricting member367is secured to the second gear G8with the at least two teeth367A and the teeth of the second gear G8. Thus, the restricting member367restricts the first gear G7from moving relative to the first coupling portion374and the second rotatable member66within a specific range.

The restricting member367can be coupled to the first rotatable member364to restrict the relative movement between the first rotatable member364and the second rotatable member66along the rotational axis A6if needed and/or desired. The restricting member367can be omitted from the bicycle motor unit332if needed and/or desired.

Fourth Embodiment

A bicycle motor unit432in accordance with a second embodiment will be described below referring toFIGS.29and30. The bicycle motor unit432has the same structure and/or configuration as those of the bicycle motor unit32except for the transmitting structure60. Thus, elements having substantially the same function as those in at least one of the first, second, and third embodiments will be numbered the same here and will not be described and/or illustrated again in detail here for the sake of brevity.

As seen inFIG.29, the bicycle motor unit432comprises a transmitting structure460. The transmitting structure460has substantially the same structure as the structure of the transmitting structure60described in the first embodiment. The transmitting structure460includes the first rotatable member64, the second rotatable member66, and the resisting structure68. The first rotatable member64is rotatable about the rotational axis A6. The second rotatable member66is rotatable relative to the first rotatable member64about the rotational axis A6. The first rotatable member64includes the first gear G7.

The transmitting structure460includes a radial support471. The radial support471is provided radially between the first rotatable member64and the second rotatable member66with respect to the rotational axis A6. The radial support471is a separate member from the first rotatable member64and the second rotatable member66. The radial support471is a separate member from the resisting structure68. However, the radial support471can be integrally provided with one of the first rotatable member64, the second rotatable member66, and the resisting structure68as a one-piece unitary member if needed and/or desired.

The radial support471is contactable with at least one of the first rotatable member64and the second rotatable member66to reduce a radial movement of the second rotatable member66relative to the first rotatable member64. The radial support471is contactable with at least one of the first coupling portion74and the second coupling portion76to reduce the radial movement of the second rotatable member66relative to the first rotatable member64.

In the present embodiment, the radial support471is contactable with the first rotatable member64and the second rotatable member66to reduce the radial movement of the second rotatable member66relative to the first rotatable member64. The radial support471is contactable with the first coupling portion74and the second coupling portion76to reduce the radial movement of the second rotatable member66relative to the first rotatable member64.

However, the radial support471is contactable with the first rotatable member64and the second rotatable member66to reduce the radial movement of the second rotatable member66relative to the first rotatable member64. The radial support471is contactable with the first coupling portion74and the second coupling portion76to reduce the radial movement of the second rotatable member66relative to the first rotatable member64.

As seen inFIG.30, the radial support471is at least partially provided circumferentially between the first circumferential end70A and the second circumferential end70B. In the present embodiment, the radial support471is entirely provided circumferentially between the first circumferential end70A and the second circumferential end70B. However, the radial support471can be partially provided circumferentially between the first circumferential end70A and the second circumferential end70B if needed and/or desired.

In the present embodiment, as seen inFIG.29, the radial support471extends along the rotational axis A6. As seen inFIG.30, for example, the radial support471has a columnar shape. However, the radial support471can have shapes other than the columnar shape if needed and/or desired. A total number of the radial support471is not limited to one.

In each of the first to fourth embodiments and the modifications thereof, the resisting member70of the resisting structure68includes the slidable member72. However, the resisting structure68can include any structure (e.g., teeth (e.g., splines, serrations), a deformable member such as a spring (e.g., a coil spring), a surface treatment) configured to resist the relative rotation between the first rotatable member64and the second rotatable member66if needed and/or desired. In the first embodiment, for example, the resisting structure68can include first teeth and second teeth. The first teeth protrudes radially inwardly from the first rotatable member64. The second teeth protrudes from the second rotatable member66. The first teeth and the second teeth slidably mesh to resist the relative rotation between the first rotatable member64and the second rotatable member66. The first teeth and the second teeth can be applied to the resisting member described in each of the second to fourth embodiments and the modifications thereof. The resisting structure68can be at least partially provided integrally with at least one of the first rotatable member64and the second rotatable member66if needed and/or desired. In the first embodiment, for example, the teeth can be at least partially provided integrally with at least one of the first rotatable member64and the second rotatable member66. The first teeth can be at least partially provided integrally with the first rotatable member64if needed and/or desired. The first teeth can be at least partially provided integrally with the first coupling portion74if needed and/or desired. The first teeth can be applied to the resisting member described in each of the second to fourth embodiments and the modifications thereof. The second teeth can be at least partially provided integrally with the second rotatable member66if needed and/or desired. The second teeth can be at least partially provided integrally with the second coupling member76if needed and/or desired. The second teeth can be applied to the resisting member described in each of the second to fourth embodiments and the modifications thereof.

In the bicycle motor unit32described in the first embodiment, the first rotatable member64is rotatably coupled to the second rotatable member66via the resisting structure68. However, the first rotatable member64can be rotatably coupled to the second rotatable member66via the resisting structure68and another member such as a gear if needed and/or desired. Structures other than the resisting structure68can be provided between the first rotatable member64and the second rotatable member66if needed and/or desired. The same modifications can be applied to the bicycle motor units232,332, and432described in the second to fourth embodiments and the modifications thereof if needed and/or desired.

Each of the bicycle motor units32,232,332, and432and the modifications thereof is applied to the bicycle derailleur RD. However, at least one of the bicycle motor units32,232,332, and432and the modifications thereof can be applied to other devices such as the bicycle derailleur FD, an adjustable seatpost, a suspension, and an assist driving unit if needed and/or desired.

The additional transmitting structure62can be omitted from each of the bicycle motor units32,232,332, and432and the modifications thereof. The structure of the additional transmitting structure62is not limited to the structure described in each of the first to fourth embodiments and the modifications thereof.

The terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein.

The phrase “at least one of” as used in this disclosure means “one or more” of a desired choice. For one example, the phrase “at least one of” as used in this disclosure means “only one single choice” or “both of two choices” if the number of its choices is two. For other example, the phrase “at least one of” as used in this disclosure means “only one single choice” or “any combination of equal to or more than two choices” if the number of its choices is equal to or more than three. For instance, the phrase “at least one of A and B” encompasses (1) A alone, (2), B alone, and (3) both A and B. The phrase “at least one of A, B, and C” encompasses (1) A alone, (2), B alone, (3) C alone, (4) both A and B, (5) both B and C, (6) both A and C, and (7) all A, B, and C. In other words, the phrase “at least one of A and B” does not mean “at least one of A and at least one of B” in this disclosure.

Finally, terms of degree such as “substantially,” “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. All of numerical values described in the present application can be construed as including the terms such as “substantially,” “about” and “approximately.”