US20140221151A1 - Bicycle drive unit - Google Patents
Bicycle drive unit Download PDFInfo
- Publication number
- US20140221151A1 US20140221151A1 US13/761,516 US201313761516A US2014221151A1 US 20140221151 A1 US20140221151 A1 US 20140221151A1 US 201313761516 A US201313761516 A US 201313761516A US 2014221151 A1 US2014221151 A1 US 2014221151A1
- Authority
- US
- United States
- Prior art keywords
- crank axle
- sprocket
- drive unit
- pawl
- axle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60W20/00—Control systems specially adapted for hybrid vehicles
- B60W20/40—Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
- B62M6/00—Rider propulsion of wheeled vehicles with additional source of power, e.g. combustion engine or electric motor
- B62M6/40—Rider propelled cycles with auxiliary electric motor
- B62M6/55—Rider propelled cycles with auxiliary electric motor power-driven at crank shafts parts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D41/00—Freewheels or freewheel clutches
- F16D41/24—Freewheels or freewheel clutches specially adapted for cycles
- F16D41/26—Freewheels or freewheel clutches specially adapted for cycles with provision for altering the action
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D41/00—Freewheels or freewheel clutches
- F16D41/24—Freewheels or freewheel clutches specially adapted for cycles
- F16D41/30—Freewheels or freewheel clutches specially adapted for cycles with hinged pawl co-operating with teeth, cogs, or the like
Definitions
- the present invention generally relates to a bicycle drive unit.
- the present invention relates to a drive unit for an electrically assisted bicycle.
- a coaster brake is conventionally known that is disposed on a bicycle (see European Patent Application Publication No. 2 380 806 A2 (Patent Citation 1) and Japanese Patent No. 4959858 (Patent Citation 2), for example).
- a bicycle crank arm and a front gear are non-rotatably coupled to each other.
- the coaster brake is disposed on a bicycle rear hub, and is operatively coupled to the front gear.
- the coaster brake is operated.
- an electrically assisted bicycle is conventionally known that uses a motor output as assisting power (see Japanese Laid-Open Patent Application Publication No. H08-310478 (Patent Citation 3), for example).
- a pedaling force which is inputted by the pedals is transmitted and the transmitted drive force is combined with a drive force from the motor, the combined drive force is transmitted to the rear wheel, thereby causing the rear wheel to rotate.
- the Patent Citation 3 discloses a one-way clutch disposed between a crank arm and a front gear.
- the one-way clutch prevents a rotation of the crank arm in response to a rotation of an electric motor.
- the front gear does not rotate.
- One aspect is to provide a bicycle drive unit that can be utilized with a bicycle coaster brake.
- a bicycle drive unit includes a motor, a crank axle, a torque combining mechanism, and a clutch mechanism.
- the crank axle is rotatable about a first rotational axis.
- the torque combining mechanism is operatively coupled to the motor and the crank axle to combine rotational outputs of the motor and the crank axle.
- the torque combining mechanism has a sprocket mounting portion that is configured to be operatively attached to a sprocket such that the sprocket rotates about a second rotational axis of the sprocket in a first direction as the crank axle rotates about the first rotational axis in the first direction.
- the clutch mechanism is operatively disposed between the crank axle and the sprocket.
- the clutch mechanism is configured to rotate the sprocket about the second rotational axis in a second direction as the crank axle rotates about the first rotational axis in the second direction.
- the second direction is opposite the first direction.
- the first and second rotational axes are coincident with each other.
- the clutch mechanism permits a relative rotation between the crank axle and the sprocket in the first direction.
- the bicycle drive unit further includes a gear shifting mechanism.
- the gear shifting mechanism includes a support axle, an input part, an output part, a planetary gear unit.
- the input part is rotatably supported on the support axle and operatively coupled to the crank axle.
- the output part is rotatably supported on the support axle and operatively coupled to the torque combining mechanism.
- the planetary gear unit is disposed between the input part and the output part.
- the clutch mechanism is supported to the support axle of the gear shifting mechanism such that the clutch mechanism is operatively disposed between a planetary gear carrier of the planetary gear unit and the output part of the gear shifting mechanism.
- the clutch mechanism includes a toothed part, a pawl support, an engagement pawl, and a biasing member.
- the toothed part is disposed on one of the output part of the gear shifting mechanism and the planetary gear carrier of the planetary gear unit.
- the pawl support is movably attached to the other of the output part of the gear shifting mechanism and the planetary gear carrier of the planetary gear unit.
- the engagement pawl is movably mounted to the pawl support between a release position and an engagement position.
- the biasing member biases the engagement pawl towards the engagement position.
- the clutch mechanism includes an internally toothed part, a pawl support, an engagement pawl, a biasing member, and a control part.
- the internally toothed part is disposed on an inner peripheral surface of the output part of the gear shifting mechanism.
- the pawl support is movably attached to the planetary gear carrier of the planetary gear unit.
- the engagement pawl is movably mounted to the pawl support between a release position and an engagement position.
- the biasing member biases the engagement pawl towards the engagement position.
- the control part is disposed on an outer peripheral surface of the planetary gear carrier of the planetary gear unit. The control part selectively causes the engagement pawl to engage with the toothed part as the crank axle rotates in the second direction such that the clutch mechanism transmits a rotation of the crank axle to the output part of the gear shifting mechanism.
- the pawl support has one of a recess and a projection disposed in a circumferential direction of the pawl support.
- the planetary gear carrier of the planetary gear unit has the other of recess and a projection located in the recess.
- the recess and the projection are arranged relative to each other with circumferential spacing therebetween to provide a limited range of relative rotation between the pawl support and the planetary gear carrier.
- the projection has a contact surface that circumferentially contacts with an inside surface of the recess as the crank axle rotates in the first direction such that the rotation of the crank axle in the first direction is transmitted from the planetary gear carrier of the planetary gear unit to the output part of the gear shifting mechanism.
- the clutch mechanism further includes a retaining member operatively disposed between the support axle and the pawl support.
- the retaining member maintains relative angular position between the pawl support and the support axle before the engagement pawl engages with the output part.
- the retaining member of the clutch mechanism further includes a slide spring having a leg portion and a ring portion.
- the leg portion is non-rotatably coupled to the support axle of the gear shifting mechanism.
- the ring portion extends from the leg portion and is disposed in an outer circumferential groove of the pawl support of the clutch mechanism.
- the planetary gear unit includes first and second sun gears that are operatively connected by a slide spring.
- the slide spring has a leg portion and a ring portion.
- the leg portion is disposed in a receiving hole of the first sun gear.
- the ring portion extends from the leg portion and is disposed in an inner circumferential groove of the second sun gear.
- the clutch mechanism is supported on one of the crank axle, the sprocket and the torque combining mechanism between the crank axle and the sprocket.
- the bicycle drive unit further includes a gear shifting mechanism.
- the gear shifting mechanism includes a support axle, an input part, an output part, and a planetary gear unit.
- the input part is rotatably supported on the support axle and is operatively coupled to the crank axle.
- the output part is rotatably supported on the support axle and is operatively coupled to the torque combining mechanism.
- the planetary gear unit is disposed between the input part and the output part.
- the clutch mechanism includes a toothed part, a pawl support, an engagement pawl, and a biasing member.
- the toothed part is disposed on one of the sprocket mounting portion and the crank axle.
- the pawl support is fixedly coupled to the other of the sprocket mounting portion and the crank axle.
- the engagement pawl is movably mounted to the pawl support between a release position and an engagement position.
- the biasing member biases the engagement pawl towards the engagement position.
- the clutch mechanism includes a toothed part, a pawl support, an engagement pawl, and a biasing member.
- the toothed part is disposed on one of the sprocket and the crank axle.
- the pawl support is fixedly coupled to the other of the sprocket and the crank axle.
- the engagement pawl is movably mounted to the pawl support between a release position and an engagement position.
- the biasing member biases the engagement pawl towards the engagement position.
- the clutch mechanism includes an internally toothed part, a pawl support, an engagement pawl, a biasing member, and a control part.
- the internally toothed part is disposed on an inner peripheral surface of the sprocket.
- the pawl support is fixedly coupled to the crank axle.
- the engagement pawl is movably mounted to the pawl support between a release position and an engagement position.
- the biasing member biases the engagement pawl towards the engagement position.
- the control part is disposed on an inner peripheral surface of an output member of the torque combining mechanism. The control part selectively causes the engagement pawl to engage with the toothed part as the crank axle rotates in the second direction such that the clutch mechanism transmits a rotation of the crank axle to the sprocket.
- control part is aligned with the toothed part as the crank axle rotates in the first direction such that the engagement pawl slides over the control part and the toothed part as the crank axle rotates in the first direction.
- the sprocket mounting portion of the torque combining mechanism has one of a recess and a projection.
- the sprocket has the other of the recess and the projection.
- the recess and the projection are arranged relative to each other with circumferential spacing therebetween to provide a limited range of relative rotation between the sprocket mounting portion of the torque combining mechanism and the sprocket.
- the recess has an inside surface that circumferentially contacts with a contact surface of the projection as the crank axle rotates in the first direction such that a rotation of the crank axle in the first direction is transmitted from the sprocket mounting portion of the torque combining mechanism to the sprocket.
- the motor includes a crank axle receiving hole.
- the crank axle is rotatably disposed in the crank axle receiving hole of the motor.
- the torque combining mechanism is operatively connected to a rotational output portion of the motor through a one-way clutch to receive the rotational output of the motor.
- FIG. 1 is a side elevational view of a drive train of an electrically assisted bicycle that is equipped with a drive unit in accordance with a first embodiment
- FIG. 2 is a cross-sectional view illustrating the drive unit in accordance with the first embodiment, taken along II-II line in FIG. 1 ;
- FIG. 3 is an enlarged cross-sectional view of a gear shifting mechanism of the drive unit illustrated in FIG. 2 ;
- FIG. 4 is an exploded perspective view of a clutch mechanism of the drive unit illustrated in FIG. 2 ;
- FIG. 5 is an exploded perspective view of first and second sun gears of the gear shifting mechanism of the drive unit illustrated in FIG. 2 ;
- FIG. 6 is a cross-sectional view illustrating the clutch mechanism of the drive unit illustrated in FIG. 2 , taken along VI-VI line in FIG. 3 , with an engagement pawl disengaged from an internally toothed part;
- FIG. 7 is a cross-sectional view illustrating the clutch mechanism of the drive unit illustrated in FIG. 2 , taken along VII-VII line in FIG. 3 , with the engagement pawl engaged with the internally toothed part;
- FIG. 8 is an elevational view of a slide spring disposed between first and second sun gears of the gear shifting mechanism illustrated in FIG. 5 , illustrating an unloaded state of the slide spring;
- FIG. 9 is a cross-sectional view of the slide spring illustrated in FIG. 8 ;
- FIG. 10 is an elevational view of a slide spring of the clutch mechanism illustrated in FIG. 4 , illustrating a loaded state of the slide spring;
- FIG. 11 is a top plan view of the slide spring illustrated in FIG. 10 , illustrating an unloaded state of the slide spring;
- FIG. 12 is a cross-sectional view illustrating a drive unit in accordance with a second embodiment:
- FIG. 13A is an elevational view of a clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which a crank axle is stationary;
- FIG. 13B is an elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which a sprocket mounting portion start to rotate from an initial position in a forward rotational direction while a crank axle rotates in the forward rotational direction;
- FIG. 13C is an elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by five degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction;
- FIG. 13D is an elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by twenty degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction;
- FIG. 13E is an elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by twenty-five degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction;
- FIG. 13F is an elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the crank axle is stopped and the crank axle is rotated in a rearward direction;
- FIG. 13G is a partial elevational view of a clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the crank axle is stationary;
- FIG. 13H is a partial elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the sprocket mounting portion start to rotate from the initial position in the forward rotational direction while the crank axle rotates in the forward rotational direction;
- FIG. 13I is a partial elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by five degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction;
- FIG. 13J is a partial elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by twenty degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction;
- FIG. 13K is a partial elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by twenty-five degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction;
- FIG. 13L is a partial elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the crank axle is stopped and the crank axle is rotated in a rearward direction;
- FIG. 13M is a partial elevational view of the clutch mechanism of the drive unit illustrated in FIG. 12 , illustrating a state in which the crank axle is further rotated in the rearward direction;
- FIG. 14 is a cross-sectional view illustrating a drive unit in accordance with a third embodiment.
- FIG. 15 is a cross-sectional view illustrating a drive unit in accordance with a fourth embodiment.
- a drive unit 10 is illustrated in accordance with a first embodiment.
- the drive unit 10 is disposed on a drive train 11 of an electrically assisted bicycle.
- FIG. 1 only illustrates portions related to the drive train 11 of the electrically assisted bicycle since other portions of the electrically assisted bicycle can be conventional. Thus, detailed description of the electrically assisted bicycle will be omitted for the sake of brevity.
- the drive train 11 basically includes a pair of pedals 100 , a pair of crank arms 101 , the drive unit 10 , a first chain 102 , a rear sprocket 103 and a rear hub 104 .
- the pedals 100 are rotatably mounted to the free ends of the crank arms 101 , respectively.
- the inner ends of the crank arms 101 are fixed to opposite ends of a crank axle 14 (see FIG. 2 ) of the drive unit 10 , respectively.
- the first chain is operatively connected between the drive unit 10 and the rear sprocket 103 .
- pedaling force acting on the pedals 100 is transmitted to the rear hub 104 that is rotatably coupled to a rear hub axle 105 to rotate a rear wheel (not shown) of the electrically assisted bicycle via the following transmission passage: the crank arms 101 ⁇ the drive unit 10 ⁇ the first chain 102 the rear sprocket 103 ⁇ the rear hub 104 .
- the drive unit 10 While transmitting the pedaling force, the drive unit 10 synthesizes a motor output torque as an assisting power for assisting the pedaling force. In the illustrated embodiment, when a pedaling force more than a prescribed threshold is detected, then the motor output torque corresponding to the pedaling force is generated as the assisting power.
- the drive unit 10 is usually arranged in a vicinity of a connecting section between a seat tube (not shown) of a bicycle frame and a down tube (not shown) of the bicycle frame.
- a battery for the drive unit 10 is arranged along a rear carrier, the down tube or the seat tube.
- the rear hub 104 is equipped with a coaster brake 104 a .
- the coaster brake 104 a is operated for generating a braking force to the rear wheel via the rear hub 104 in response to a rearward rotation of the crank arms 101 .
- the coaster brake 104 a of the rear hub 104 is operated in response to the rearward rotation of the crank arms 101 via the drive unit 10 , the first chain 102 and the rear sprocket 103 . Since coaster brakes are conventionally well known, the detailed description will be omitted for the sake of brevity.
- the drive unit 10 is arranged in a vicinity of the crank arms 101 .
- the drive unit 10 has a housing 12 , a crank axle 14 , a first rotation transmitting member 16 , an intermediate axle 18 , a second rotation transmitting member 20 , a support axle 22 , a second chain 24 , a third rotation transmitting member 26 and a front sprocket 28 (e.g., a sprocket).
- the crank axle 14 , the intermediate axle 18 and the support axle 22 are arranged to extend parallel to each other at spaced locations. As shown in FIG.
- the drive unit 10 has a motor 30 , a gear shifting mechanism 32 , a reduction gear unit 34 , a torque combining mechanism 36 , and a clutch mechanism 38 .
- the bicycle drive unit 10 includes the motor 30 , the crank axle 14 , the torque combining mechanism 36 , and the clutch mechanism 38 .
- the housing 12 accommodates the first rotation transmitting member 16 , the second rotation transmitting member 20 , the third rotation transmitting member 26 , the motor 30 , the gear shifting mechanism 32 , the reduction gear unit 34 , the torque combining mechanism 36 , and the clutch mechanism 38 .
- the housing 12 is a member made of, for example, aluminum or another metal. However, a part or the entire of the housing 12 can also be made of a synthetic resin.
- the housing 12 has a first side wall 12 a and a second side wall 12 b .
- the first side wall 12 a and the second side wall 12 b are independently formed as separate parts, and face with each other in an axial direction of the crank axle 14 .
- the housing 12 has a housing main body containing the second side wall 12 b and a lid member containing the first side wall 12 a .
- the lid member is anchored detachably on the opening of the housing main body by bolts or other anchoring members to form an accommodating space for accommodating the first rotation transmitting member 16 , the second rotation transmitting member 20 , the third rotation transmitting member 26 , the motor 30 , the gear shifting mechanism 32 , the reduction gear unit 34 , the torque combining mechanism 36 , and the clutch mechanism 38 .
- the first side wall 12 a has a first side wall main body 12 c and a first plate member 12 d .
- the first plate member 12 d is installed detachably and non-rotatably on the first engagement hole 12 e formed on the first side wall main body 12 c .
- the second side wall 12 b has a second side wall main body 12 f.
- the first plate member 12 d is made of a metal material different from the first side wall main body 12 c . Of course, alternatively, they can be made of the same material as the first side wall main body 12 c .
- the first plate member 12 d is installed detachably from the outer side of the housing 12 on the first side wall main body 12 c.
- the first plate member 12 d is formed here as a round plate, with serrations and flanges for engagement with the first engagement hole 12 e formed on their outer peripheral portions.
- the serrations of the first plate member 12 d are engaged with the first engagement hole 12 e .
- the flange of the first plate member 12 d contacts with the side surface of the first side wall main body 12 c .
- serration grooves for engaging with the serrations of the first plate member 12 d are formed. With this configuration, the first plate member 12 d is non-rotatably coupled to the first side wall main body 12 c.
- the housing 12 has a pair of round shaped first holes 13 a and 13 b , a pair of second holes 13 c and 13 d .
- the first holes 13 a and 13 b are formed on the first side wall main body 12 c and the second side wall main body 12 f , respectively.
- first and second bearings 39 a and 39 b such as a ball bearing, are arranged in the first holes 13 a and 13 b , respectively.
- the second holes 13 c and 13 d are formed on the first plate member 12 d and the second wall main body 12 f .
- the support axle 22 is non-rotatably arranged in the second holes 13 c and 13 d .
- the first plate member 12 d is detachably coupled to the first side wall main body 12 c .
- the first plate member 12 d can be pressed in and integrated with the first side wall main body 12 c.
- the crank axle 14 is a metal axle member made of, for example, iron, stainless steel, or the like.
- the crank axle 14 is rotatable about a rotational axis X 1 (e.g., a first rotational axis).
- the crank axle 14 is rotatably supported by the first bearing 39 a and the second bearing 39 b .
- the two ends of the crank axle 14 are arranged to protrude out from the first side wall 12 a and the second side wall 12 b , respectively.
- the crank arms 101 are detachably and non-rotatably coupled to the crank axle 14 .
- the crank axle 14 has a large-diameter flange section 14 a for positioning the first rotation transmitting member 16 in the axial direction and a serration section 14 b for connecting with the first rotation transmitting member 16 .
- the large-diameter flange section 14 a and the serration section 14 b are arranged adjacent to each other.
- the flange section 14 a is formed on the entire circumference in the circumferential direction of the crank axle 14 .
- the flange section 14 a can be formed intermittently in the circumferential direction and protruding out from the crank axle 14 .
- the first rotation transmitting member 16 is non-rotatably coupled to the crank axle 14 such that the first rotation transmitting member 16 transmits the rotation of the crank arms 101 .
- the first rotation transmitting member 16 has a first gear 16 a made of, for example, a synthetic resin or a metal.
- the first gear 16 a is connected to the serration section 14 b of the crank axle 14 such that the first gear 16 a and the crank axle 14 rotate together.
- the first gear 16 a is fastened to the crank axle 14 by press-fit, bonding or another appropriate fastening manner.
- the first gear 16 a makes contact with the flange section 14 a of the crank axle 14 such that the first gear 16 a is positioned in the axial direction of the crank axle 14 .
- the first gear 16 a is rotatably supported to the housing 12 via the first bearing 39 a .
- the crank axle 14 is rotatably supported to the housing 12 via the first bearing 39 a and the first gear 16 a.
- the intermediate axle 18 is an axle member made of iron, stainless steel or another metal.
- the intermediate axle 18 has first and second end portions 18 a and 18 b .
- the first end portion 18 a is supported on the first side wall main body 12 c
- the second end portion 18 b is supported on a second case 56 b of a motor case 56 of the motor 30 .
- the intermediate axle 18 rotatably supports the second rotation transmitting member 20 .
- the second rotation transmitting member 20 is a member that transmits the rotation of the first rotation transmitting member 16 .
- the second rotation transmitting member 20 has a second gear 20 a that meshes with the first gear 16 a , and a first sprocket 20 b that rotates together with the second gear 20 a .
- the second rotation transmitting member 20 is a member made of, for example, a synthetic resin or a metal.
- the second rotation transmitting member 20 is rotatably supported on the intermediate axle 18 via a bearing 40 , such as, for example, a needle-shaped roller bearing.
- the second gear 20 a has an engagement section 20 c engaged with an inner peripheral portion 20 d of the first sprocket 20 b .
- the engagement section 20 c is formed on a toothed surface that is not engaged with the first gear 16 a among the toothed surface of the second gear 20 a .
- On the inner peripheral portion 20 d of the first sprocket 20 b an engagement portion engaged with at least a portion of the second gear 20 a is formed.
- the second gear 20 a and the first sprocket 20 b are non-rotatably coupled to each other.
- retainers are disposed on the second gear 20 a for prohibiting an axial movement of the first sprocket 20 b in the axial direction of the intermediate axle 18 .
- the retainers are disposed on both sides of the first sprocket 20 b in the axial direction of the intermediate axle 18 .
- the support axle 22 is arranged to support the gear shifting mechanism 32 and the clutch mechanism 38 with respect to the housing 12 .
- the support axle 22 has end portions that extend through the second holes 13 c and 13 d .
- the end portions of the support axle 22 are fastened to the first and second side walls 12 a and 12 b with the nuts 42 , respectively. As a result, they are fastened to the first and second side walls 12 a and 12 b , respectively.
- the support axle 22 extends through the gear shifting mechanism 32 and the clutch mechanism 38 .
- the support axle 22 rotatably supports the third rotation transmitting member 26 .
- the third rotation transmitting member 26 is a member that transmits the rotation of the second rotation transmitting member 20 .
- the rotation of the second rotation transmitting member 20 is transmitted by the second chain 24 to the third rotation transmitting member 26 .
- the third rotation transmitting member 26 has a second sprocket 26 a engaged with the second chain 24 .
- the second chain 24 is wound on the first sprocket 20 b and the second sprocket 26 a .
- the second sprocket 26 a is operatively coupled to the gear shifting mechanism 32 .
- the second sprocket 26 a is fixedly coupled to an input part 64 of the gear shifting mechanism 32 .
- the second sprocket 26 a is rotatably supported on the support axle 22 via the input part 64 .
- the motor 30 is an inner rotor-type motor.
- the motor 30 has the motor case 56 , a rotor 58 that is rotatably supported on the motor case 56 , and a stator 60 installed on the motor case 56 .
- the motor case 56 has a first case 56 a integrally formed with the housing 12 , and the second case 56 b detachably coupled to the first case 56 a .
- the motor case 56 further has an axle supporting recess 56 c that supports the second end portion 18 b of the intermediate axle 18 on the second case 56 b.
- the rotor 58 is a cylindrical member that is coaxially arranged relative to the crank axle 14 .
- the crank axle 14 extends through the rotor 58 .
- the rotor 58 has a magnet unit 58 a with a plurality of magnetic poles arranged on the outer peripheral portion of the rotor 58 side by side in the circumferential direction.
- the rotor 58 of the motor 30 has a crank axle receiving hole 58 b .
- the crank axle 14 is rotatably disposed in the crank axle receiving hole 58 b of the rotor 58 of the motor 30 .
- the rotor 58 is rotatably supported on the motor case 56 by a pair of bearings 62 a and 62 b , such as, for example, ball bearings.
- the bearings 62 a and 62 b are arranged on the outer peripheral side of the rotor 58 .
- the bearing 62 a is installed on the first case 56 a
- the stator 60 is arranged opposite to the rotor 58 on the outer peripheral side of the rotor 58 .
- the stator 60 has a plurality of coils 60 a arranged at a certain interval in the circumferential direction.
- the stator 60 is fixedly coupled to the inner peripheral portion of the first case 56 a.
- the motor 30 is driven by an inverter (not shown).
- the inverter is driven by a controller (not shown).
- the controller controls the inverter based on the pedaling force and the speed of the bicycle.
- the rotational axes of the motor 30 and the crank axle 14 are coincident with each other.
- the drive unit 10 can be further simplified.
- the motor 30 and the crank axle 14 can be arranged with respect to each other such that the rotational axes the rotational axes of the motor 30 and the crank axle 14 are offset with respect to each other.
- the gear shifting mechanism 32 is arranged on the power transmission passage between the third rotation transmitting member 26 and the torque combining mechanism 36 .
- the gear shifting mechanism 32 has a shifting motor unit 32 a .
- the gear shifting mechanism 32 has a gear shifting main body 32 b .
- the shifting motor unit 32 a rotates an actuating member of the gear shifting main body 32 b to a prescribed phase upon receiving a shift operation from a shifter installed on a handle of the bicycle.
- the shifting motor unit 32 a is a conventionally well-known motor unit, such as a motor unit disclosed in, for example. Japanese Patent No. 3529723.
- shifting motor unit 32 a can be replaced with a conventionally well-known mechanism for shifting the power transmission paths of the gear shifting main body 32 b , such as a wire operated actuator operated by receiving a shift operation from a shifter installed on the handle of the bicycle.
- the gear shifting main body 32 b is a transmission unit that allows selection from a plurality of (e.g., 8) gear ratios.
- the configuration of the gear shifting main body 32 b is basically identical to a conventionally well-known transmission unit, such as a transmission unit disclosed in U.S. Pat. No. 6,607,465 or U.S. Patent No. 7,682,283, except for the configurations as described in detail below.
- the gear shifting main body 32 b of the gear shifting mechanism 32 mainly includes the support axle 22 , the input part 64 , a planetary gear unit 66 , and an output part 68 .
- the rotation of the third rotation transmitting member 26 is transmitted to the input part 64 , the planetary gear unit 66 and the output part 68 .
- the input part 64 , the planetary gear unit 66 and the output part 68 are rotatably supported on the support axle 22 , respectively.
- the input part 64 is rotatably supported on the support axle 22 and operatively coupled to the crank axle 14 .
- the second sprocket 26 a of the third rotation transmitting member 26 is fixedly coupled to the input part 64 such that they can rotate together.
- the planetary gear unit 66 is disposed between the input part 64 and the output part 68 .
- the planetary gear unit 66 selectively establishes a plurality of (e.g., 8) gear ratios.
- the output part 68 is rotatably supported on the support axle 22 and operatively coupled to the torque combining mechanism 36 .
- the output part 68 outputs the rotation after changing the rotational speed by the planetary gear unit 66 to the torque combining mechanism 36 .
- the gear shifting mechanism 32 is arranged in the drive unit 10 . It is possible to select from a plurality of gear ratios by the gear shifting mechanism 32 . Consequently, assisting driving by the motor 30 can be carried out at a high efficiency. Also, even when an internal transmission unit is adopted as the gear shifting mechanism 32 , as the force acting on the gear shifting mechanism 32 is small, the transmission operation can be carried out quickly.
- the configurations of the gear shifting mechanism 32 will be described in detail later.
- the reduction gear unit 34 transmits the rotation of the rotor 58 of the motor 30 to a torque transmitting member 70 .
- the reduction gear unit 34 has one or more gears.
- the reduction gear unit 34 has a first planetary gear mechanism 72 and a second planetary gear mechanism 74 .
- the first planetary gear mechanism 72 has a first sun gear 72 a connected to the rotor 58 , a plurality of first planetary gears 72 b , a first carrier 72 c rotatably supporting the first planetary gears 72 b , and a first ring gear 72 d fixedly coupled to the housing 12 .
- the second planetary gear mechanism 74 has a second sun gear 74 a connected to the first carrier 72 c , a plurality of second planetary gears 74 b , a second carrier 74 c rotatably supporting the second planetary gears 74 b , and a second ring gear 74 d fixedly coupled to the housing 12 .
- the rotational output of the reduction gear unit 34 is transmitted via the torque transmitting member 70 to the torque combining mechanism 36 .
- the torque transmitting member 70 is integrally formed with the second carrier 74 c .
- the torque transmitting member 70 is rotatably supported by a second gear member 78 of the torque combining mechanism 36 .
- the torque transmitting member 70 supports a plurality of clutch pawls 80 a of a one-way clutch 80 .
- the torque combining mechanism 36 transmits the rotating force of the motor 30 and the rotating force of the crank axle 14 to the front sprocket 28 .
- the torque combining mechanism 36 is operatively coupled to the motor 30 and the crank axle 14 to combine the rotational outputs of the motor 30 and the crank axle 14 .
- the torque combining mechanism 36 has a first gear member 76 fixedly coupled to the output part 68 of the gear shifting mechanism 32 , a second gear member 78 that meshes with the first gear member 76 , and the one-way clutch 80 .
- the torque combining mechanism 36 is operatively connected to the rotor 58 (e.g., a rotational output portion) of the motor 30 through the one-way clutch 80 to receive the rotational output of the motor 30 .
- the second gear member 78 is rotatably supported on the housing 12 via the second bearing 39 b on the housing 12 .
- a bearing 82 in the form of, for example, a ball bearing is installed. Consequently, the crank axle 14 is rotatably supported on the housing 12 via the second gear member 78 .
- the second gear member 78 has a first annular recess 78 a in which the one-way clutch 80 is disposed and a second annular recess 78 b in which the bearing 39 b is disposed.
- the second gear member 78 of the torque combining mechanism 36 has a sprocket mounting portion 78 c.
- the first annular recess 78 a is formed in annular shape on the surface of the housing 12 opposite to the second side wall 12 b .
- the outer peripheral portion on the inner side of the first annular recess 78 a rotatably supports the torque transmitting member 70 .
- the second annular recess 78 b is formed in annular shape on the surface opposite to the second side wall 12 b .
- the inner ring of the second bearing 39 b is disposed in the second annular recess 78 b .
- the sprocket mounting portion 78 c is configured to be operatively attached to the front sprocket 28 such that the front sprocket 28 rotates about the rotational axis X 1 (e.g., a second rotational axis of a sprocket) in the forward rotational direction (e.g., a first direction) as the crank axle 14 rotates about the rotational axis X 1 in the forward rotational direction.
- the sprocket mounting portion 78 c extends in annular shape in the axial direction of the crank axle 14 from the outer peripheral surface on the inner side of the second annular recess 78 b .
- the second annular recess 78 b is formed on the radially inner side of the first annular recess 78 a .
- the front sprocket 28 is fixedly coupled to a connecting section 78 d on the inner peripheral surface of the sprocket mounting portion 78 c .
- the connecting section 78 d can have serrations.
- the front sprocket 28 is pressed into the connecting section 78 d and is fixed by caulking with a plastic deformation, for example.
- the second gear member 78 and the front sprocket 28 rotate together.
- the one-way clutch 80 only transmits the forward rotation of the motor 30 that drives the bicycle in the forward direction to the second gear member 78 .
- the one-way clutch 80 has a clutch pawl 80 a , a clutch tooth 80 b , and an inner side member 80 c.
- the clutch pawl 80 a is accommodated such that the clutch pawl 80 a can pivot along the outer peripheral surface of the inner side member 80 c between a release position and an engagement position.
- the clutch pawl 80 a is biased towards the engagement position.
- the clutch tooth 80 b is formed on the inner peripheral surface on the outer side of the first annular recess 78 a .
- the inner side member 80 c is formed in annular shape.
- the torque transmitting member 70 is rotatably supported on the inner peripheral portion of the inner side member 80 c.
- the front sprocket 28 has an annular section 28 b with sprocket teeth 28 a formed on the outer peripheral portion, and a cylindrical section 28 c integrally formed on the inner peripheral portion of the annular section 28 b .
- the outer peripheral surface of the cylindrical section 28 c is pressed into the inner peripheral portion of the second annular recess 78 b , and the tip portion of the cylindrical section 28 c is fixed by caulking.
- the method for fixing the front sprocket 28 is not limited to the press-fit.
- the front sprocket 28 can be fixed to the second gear member 78 by any other suitable manner, such as screwing, bonding, fusion welding, etc.
- the front sprocket 28 rotates about the rotational axis X 1 of the crank axle 14 .
- the rotational axis of the crank axle 14 e.g., a first rotational axis
- the rotational axis of the front sprocket 28 e.g., a second rotational axis
- front sprocket 28 and the crank axle 14 can be arranged with respect to each other such that the rotational axes of the front sprocket 28 and the crank axle 14 are offset with respect to each other.
- the planetary gear unit 66 of the gear shifting mechanism 32 includes a power transmitting mechanism 112 and a shift/assist mechanism 114 .
- the power transmitting mechanism 112 is disposed between the input part 64 and the output part 68 for communicating rotational power from the input part 64 to the output part 68 through a plurality of power transmission paths.
- the shift/assist mechanism 114 controls the selection of the power transmission paths by receiving the rotational input from the shifting motor unit 32 a.
- the input part 64 is rotatably supported on the support axle 22 through a ball bearing 118 and a bearing cone 120 .
- the bearing cone 120 is maintained in place by an actuator plate 122 , a spacer 124 , a washer 126 and a lock nut 128 .
- the output part 68 has a left cup 130 and a right cup 132 .
- the left cup 130 is non-rotatably fitted at the left side of an inner peripheral surface of the output part 68
- the right cup 132 is non-rotatably fitted at the right side of the inner peripheral surface of the output part 68 .
- the left cup 130 rotatably supports the output part 68 relative to the input part 64 through ball bearings 136 .
- the right cup 132 rotatably supports the output part 68 on the support axle 22 through a ball bearing 140 and a cone 142 .
- the cone 142 is maintained on the support axle 22 by a stop nut 144 .
- the left cup 130 and the right cup 132 are independently formed as separate members from the output part 68 .
- the left cup 130 or the right cup 132 can be integrally formed with the output part 68 as a one-piece, unitary member.
- the power transmitting mechanism 112 includes a first sun gear 148 , a separate second sun gear 150 , a separate third sun gear 152 , and a separate fourth sun gear 154 .
- the first sun gear 148 is non-rotatably supported to the support axle 22 .
- the first sun gear 148 includes a clutch cam portion 156 , and a plurality of first sun gear teeth 158 (e.g., 48 T) formed on an outer peripheral surface thereof, and an inner peripheral second sun gear contact surface 160 .
- the second sun gear 150 is rotatably supported around the support axle 22 adjacent to the first sun gear 148 .
- the second sun gear 150 includes an outer peripheral first sun gear contact surface 162 for slidably contacting the second sun gear contact surface 160 on the first sun gear 148 , a plurality of second sun gear ratchet teeth 168 (e.g., 12 T) formed on an inner peripheral surface thereof for engaging a second sun gear pawl 170 , an inner peripheral third sun gear contact surface 166 , and a plurality of second sun gear teeth 164 (e.g., 48 T) formed on an outer peripheral surface thereof.
- the second sun gear 150 further has an inner peripheral guide ring contact surface for slidably contacting an outer peripheral surface of a sun gear guide ring 176 .
- the third sun gear 152 is rotatably supported around the support axle 22 adjacent to the second sun gear 150 .
- the third sun gear 152 includes an inner peripheral first guide ring contact surface for slidably contacting the outer peripheral surface of the sun gear guide ring 176 .
- the third sun gear 152 includes a plurality of third sun gear ratchet teeth 180 (e.g., 12 T) formed on an inner peripheral surface thereof for engaging a third sun gear pawl 182 , an outer peripheral second sun gear contact surface 184 for slidably contacting the third sun gear contact surface 166 of the second sun gear 150 , and a plurality of third sun gear teeth 186 (e.g., 42 T) formed on an outer peripheral surface thereof.
- the fourth sun gear 154 includes a plurality of fourth sun gear teeth 188 (e.g., 36 T) formed on an outer peripheral surface thereof, a plurality of fourth sun gear ratchet teeth 190 (e.g., 12 T) formed on an inner peripheral surface thereof for engaging a fourth sun gear pawl 192 .
- the fourth sun gear 154 includes an inner peripheral guide ring contact surface for slidably contacting an outer peripheral surface of a guide ring 198 .
- the pawls 170 , 182 and 192 are pivotally coupled to the support axle 22 , and controlled by a shift control sleeve (not shown) for selectively switching between a free state and a lock state of the second, third and fourth sun gears 150 , 152 and 154 in a conventional manner.
- a shift control sleeve (not shown) for selectively switching between a free state and a lock state of the second, third and fourth sun gears 150 , 152 and 154 in a conventional manner.
- Each of the second, third and fourth sun gears 150 , 152 and 154 rotates about the support axle 22 in the free state, while each of the second, third and fourth sun gears 150 , 152 and 154 is prevented from rotating about the support axle 22 in the lock state.
- the power transmitting mechanism 112 further includes a planetary gear carrier 200 , a first ring gear 202 , a second ring gear 204 , a plurality of (e.g., three) first planet gears 206 , and a plurality of (e.g., three) second planetary gears 208 .
- the planetary gear carrier 200 is rotatably mounted around the support axle 22 .
- the planetary gear carrier 200 rotatably supports the first planetary gears 206 about a plurality of (e.g., three) first pinion pins 210 , and rotatably supports the second planetary gears 208 about a plurality of (e.g., three) second pinion pins 212 .
- the first and second pinion pins 210 and 212 are fixedly coupled to the planetary gear carrier 200 .
- first pinion pins 210 are equidistantly arranged on the planetary gear carrier 200 in the circumferential direction about the support axle 22
- second pinion pins 212 are equidistantly arranged on the planetary gear carrier 200 in the circumferential direction about the support axle 22
- Each of the first pinion pins 210 is concentrically arranged with respect to respective one of the second pinion pins 212 .
- the first and second pinion pins 210 and 212 are independently formed as separate members.
- the first and second pinion pins 210 and 212 that are concentrically disposed can be integrally formed as a one-piece, unitary member.
- the planetary gear carrier 200 is made of a light alloy metal such as an aluminum alloy, steel, or any other suitably material.
- the planetary gear carrier 200 can be formed by combining a plurality of separate parts.
- the first pinion pins 210 rotatably support the first planetary gears 206 , respectively.
- Each of the first planetary gears 206 has a small diameter gear portion 220 (e.g., 14 T) engaging with the first sun gear teeth 158 of the first sun gear 148 , and a large diameter gear portion 222 (e.g., 22 T) engaging with a first inner peripheral gear portion 224 (e.g., 84 T) of the first ring gear 202 .
- the second pinion pins 212 rotatably support the second planetary gears 208 , respectively.
- Each of the second planetary gears 208 includes a large diameter gear portion 226 (e.g., 29 T) engaging with the fourth sun gear teeth 188 of the fourth sun gear 154 , an intermediate diameter gear portion 228 (e.g., 18 T) engaging with the third sun gear teeth 186 of the third sun gear 152 , and a small diameter gear portion 230 (e.g., 14 T) engaging with the second sun gear teeth 164 of second sun gear 150 and an inner peripheral gear portion 232 (e.g., 78 T) of the second ring gear 204 .
- a large diameter gear portion 226 e.g., 29 T
- an intermediate diameter gear portion 228 e.g., 18 T
- a small diameter gear portion 230 e.g., 14 T
- an inner peripheral gear portion 232 e.g., 78 T
- the planetary gear carrier 200 further has a plurality (e.g., 12) of splines 238 on an inner peripheral surface of a left end portion of the planetary gear carrier 200 .
- the clutch engaging splines 238 of the planetary gear carrier 200 are selectively engaged with a plurality of splines 240 circumferentially disposed on a clutch ring 242 .
- the clutch ring 242 is slidable along a center axis of the support axle 22 between an engaging position and a disengaging position in response to the rotational input from the shifting motor unit 32 a .
- the clutch ring 242 is non-rotatably coupled to splines on an inner peripheral surface of the input part 64 .
- the clutch ring 242 couples the input part 64 with the planetary gear carrier 200 when the clutch ring 242 is located on the engaging position such that the input part 64 and the planetary gear carrier 200 rotate together.
- the input part 64 is disengaged from the planetary gear carrier 200 when the clutch ring 242 is located on the disengaging position.
- the first ring gear 202 further includes a second inner peripheral gear portion 244 (e.g., 36 T) for engaging a plurality of circumferentially disposed pawls 246 that are pivotally mounted to an outer peripheral surface of the input part 64 .
- the pawls 246 are biased radially outwardly by a pawl spring 248 and thus function as a clutch between the input part 64 and the first ring gear 202 .
- a plurality of pawls 249 also are circumferentially disposed on the outer peripheral surface of the input part 64 for driving the first ring gear 202 in response to the rearward rotation of the crank axle 14 in a conventionally well-known manner.
- the second ring gear 204 is coupled to the output part 68 via a one-way clutch 250 in the form of a roller clutch having a plurality of (e.g., 18) rollers and cam surfaces.
- the one-way clutch 250 is configured such that the one-way clutch 250 only transmits the forward rotation of the crank axle 14 to the output part 68 .
- the power transmitting mechanism 112 of the planetary gear unit 66 further includes a slide spring 254 disposed between the first and second sun gears 148 and 150 .
- the power transmitting mechanism 112 of the planetary gear unit 66 includes the first and second sun gears 148 and 150 that are operatively connected by the slide spring 254 .
- the slide spring 254 has a leg portion 254 a and a ring portion 254 b. As shown in FIG. 3 , the leg portion 254 a is disposed in a receiving hole 256 of the first sun gear 148 .
- the ring portion 254 b extends from the leg portion 254 a and is disposed in an inner circumferential groove 258 of the second sun gear 150 .
- the ring portion 254 b has a larger diameter than that of the inner circumferential groove 258 of the second sun gear 150 when the slide spring 254 is in an unloaded state as shown in FIGS. 8 and 9 .
- the ring portion 254 b of the slide spring 254 is in a loaded state while the ring portion 254 b is disposed in the inner circumferential groove 258 of the second sun gear 150 as shown in FIGS. 3 .
- the leg portion 254 a of the slide spring 254 is disposed in the receiving hole 256 of the first sun gear 148 such that the slide spring 254 is non-rotatably coupled to the first sun gear 148 .
- the ring portion 254 b of the slide spring 254 is slidably disposed in the inner circumferential groove 258 of the second sun gear 150 while the slide spring 254 is in the loaded state.
- the angular position of the second sun gear 150 about the support axle 22 with respect to the first sun gear 148 is maintained by the slide spring 254 while the rotational force applied to the second sun gear 150 is smaller than the retaining or friction force between the ring portion 254 b of the slide spring 254 and the inner circumferential groove 258 of the second sun gear 150 .
- the second sun gear 150 rotates with respect to the first sun gear 148 when the rotational force applied to the second sun gear 150 becomes larger than the retaining or friction force between the ring portion 254 b of the slide spring 254 and the second sun gear 150 .
- the clutch mechanism 38 is operatively disposed between the crank axle 14 and the front sprocket 28 .
- the clutch mechanism 38 is configured to rotate the front sprocket 28 about the rotational axis X 1 in the rearward rotational direction (e.g., a second direction) as the crank axle 14 rotates about the rotational axis X 1 in the rearward rotational direction.
- the rearward rotational direction is opposite the forward rotational direction.
- the clutch mechanism 38 permits a relative rotation between the crank axle 14 and the front sprocket 28 in the forward rotational direction (e.g., the first direction).
- the clutch mechanism 38 is supported to the support axle 22 of the gear shifting mechanism 32 such that the clutch mechanism 38 is operatively disposed between the planetary gear carrier 200 of the planetary gear unit 66 and the output part 68 of the gear shifting mechanism 32 .
- the clutch mechanism 38 includes a toothed part 260 (e.g., an internally toothed part), a pawl support 262 , a plurality of engagement pawls 264 , and a plurality of biasing members 266 .
- the clutch mechanism 38 includes a control part 268 .
- the toothed part 260 is disposed on an inner peripheral surface of the right cup 132 of the output part 68 of the gear shifting mechanism 32 .
- the toothed part 260 has a plurality of engagement teeth 260 a formed on the inner peripheral surface of the right cup 132 .
- the engagement teeth 260 a selectively engage with the engagement pawls 264 for transmitting the rearward rotation of the crank axle 14 to the output part 68 .
- the pawl support 262 is movably attached to the planetary gear carrier 200 of the planetary gear unit 66 . Specifically, the pawl support 262 is movably attached about an axially extending portion 270 of the planetary gear carrier 200 that has a large diameter section 270 a and a small diameter section 270 b .
- the pawl support 262 is integrally formed as a one-piece, unitary member, and is made of metallic material, or any other suitable material.
- the pawl support 262 has first and second annular sections 272 and 274 that are axially arranged with respect to each other.
- the first annular section 272 has a plurality of (e.g., four) pawl receiving openings 272 a that are circumferentially arranged on an outer peripheral surface of the first annular section 272 .
- the second annular section 274 has a plurality of clutch pawl mounting sections 274 a that are circumferentially arranged on an outer peripheral surface of the second annular section 274 .
- the second annular section 274 of the pawl support 262 has a plurality of recesses 278 disposed in the circumferential direction of the pawl support 262 .
- the recesses 278 are circumferentially arranged on an inner peripheral surface of the second annular section 274 .
- the planetary gear carrier 200 of the planetary gear unit 66 has a plurality of projections 280 .
- the projections 280 are circumferentially arranged on an outer peripheral surface of the large diameter section 270 a of the axially extending portion 270 of the planetary gear carrier 200 .
- the projections 280 are located in the recesses 278 , respectively. As shown in FIGS.
- the recesses 278 and the projections 280 are arranged relative to each other with circumferential spacings therebetween, respectively, to provide a limited range of relative rotation between the pawl support 262 and the planetary gear carrier 200 .
- the recesses 278 and the projections 280 are arranged relative to each other with circumferential spacings therebetween, respectively, to provide a limited range of relative rotation between the pawl support 262 and the planetary gear carrier 200 .
- the projections 280 have first contact surfaces 280 a (e.g., contact surfaces), respectively, that circumferentially contact with first inside surfaces 278 a (e.g., inside surfaces) of the recesses 278 , respectively, as the crank axle 14 rotates in the forward rotational direction such that the forward rotation of the crank axle 14 in the forward rotational direction is transmitted from the planetary gear carrier 200 of the planetary gear unit 66 to the output part 68 of the gear shifting mechanism 32 via the pawl support 262 . Furthermore, as shown in FIG.
- the projections 280 have second contact surfaces 280 b , respectively, that circumferentially contact with second inside surfaces 278 b of the recesses 278 , respectively, as the crank axle 14 rotates in the rearward rotational direction such that the rearward rotation of the crank axle 14 in the forward rotational direction is transmitted from the planetary gear carrier 200 of the planetary gear unit 66 to the output part 68 of the gear shifting mechanism 32 via the pawl support 262 .
- the first and second contact surfaces 280 a and 280 b of each of the projections 280 face in the opposite circumferential directions, while the first and second inside surfaces 278 a and 278 b of each of the recesses 278 face in the opposite circumferential directions.
- the pawl support 262 has the recesses 278
- the planetary gear carrier 200 has the projections 280
- the pawl support 262 can have a plurality of projections disposed in the circumferential directions of the pawl support 262
- the planetary gear carrier 200 of the planetary gear unit 66 can have a plurality of recesses located in the recesses.
- the recesses and the projections can be arranged relative to each other with circumferential spacings therebetween, respectively, to provide a limited range of relative rotation between the pawl support 262 and the planetary gear carrier 200 .
- the engagement pawls 264 are movably mounted to the pawl support 262 between a release position and an engagement position.
- Each of the engagement pawls 264 has an engagement end 264 a and a control end 264 b .
- the engagement ends 264 a of the engagement pawls 264 are engaged with the engagement teeth 260 a of the right cup 132 when the engagement pawls 264 are located at the engagement position, while the engagement ends 264 a of the engagement pawls 264 are disengaged from the engagement teeth 260 a of the right cup 132 when the engagement pawls 264 are located at the release position.
- the engagement pawls 264 are pivotally arranged in the pawl receiving openings 272 a of the first annular section 272 of the pawl support 262 , respectively. More specifically, the engagement pawls 264 are pivotally coupled to a plurality of pivot pins 282 , respectively. The pivot pins 282 are fixedly coupled to the first annular section 272 of the pawl support 262 in the pawl receiving openings 272 a , respectively.
- the biasing members 266 bias the engagement pawls 264 towards the engagement position.
- the biasing members 266 basically includes pawl springs operatively disposed between the engagement pawls 264 and the pawl support 262 .
- the control part 268 is disposed on an outer peripheral surface of the planetary gear carrier 200 of the planetary gear unit 66 .
- the control part 268 selectively causes the engagement pawls 264 to engage with the toothed part 260 as the crank axle 14 rotates in the rearward rotational direction such that the clutch mechanism 38 transmits the rearward rotation of the crank axle 14 to the output part 68 of the gear shifting mechanism 32 .
- the control part 268 has a plurality of control projections 284 circumferentially arranged on an outer peripheral surface of the small diameter section 270 b of the axially extending portion 270 of the planetary gear carrier 200 .
- FIG. 1 the control part 268
- the control projections 284 are engaged with the control ends 264 b of the engagement pawls 264 while the planetary gear carrier 200 rotates in response to the forward rotation of the crank axle 14 .
- This moves the engagement pawls 264 towards the release position such that the rotation of the planetary gear carrier 200 is prevented from being transmitted to the right cup 132 of the output part 68 via the engagement pawls 264 .
- the control projections 284 are disengaged with the control ends 264 b of the engagement pawls 264 while the planetary gear carrier 200 rotates in response to the rearward rotation of the crank axle 14 .
- the clutch mechanism 38 further includes a retaining member 286 operatively disposed between the support axle 22 and the pawl support 262 .
- the retaining member 286 maintains relative angular position between the pawl support 262 and the support axle 22 before the engagement pawls 264 engage with the right cup 132 of the output part 68 .
- the retaining member 286 of the clutch mechanism 38 further includes a slide spring 288 having a leg portion 288 a and a ring portion 288 b .
- the leg portion 288 a is non-rotatably coupled to the cone 142 that is fastened to the support axle 22 of the gear shifting mechanism 32 .
- the ring portion 288 b extends from the leg portion 288 a and is disposed in an outer circumferential groove 262 a of the pawl support 262 of the clutch mechanism 38 .
- the ring portion 288 b has a smaller diameter than that of the outer circumferential groove 262 a of the pawl support 262 when the slide spring 288 is in an unloaded state, as shown in FIG. 11 .
- the ring portion 288 b of the slide spring 288 is in a loaded state, as shown in FIG. 10
- the ring portion 288 b is disposed in the outer circumferential groove 262 a of the pawl support 262 .
- the leg portion 288 a of the slide spring 288 is disposed in a receiving hole 142 a of the cone 142 such that the slide spring 288 is non-rotatably coupled to the support axle 22 .
- the ring portion 288 b of the slide spring 288 is slidably disposed in the outer circumferential groove 262 a of the pawl support 262 while the slide spring 288 is in the loaded state.
- the angular position of the pawl support 262 about the support axle 22 is maintained by the slide spring 288 while the rotational force applied to the pawl support 262 is smaller than the retaining or friction force between the ring portion 288 b of the slide spring 288 and the outer circumferential groove 262 a of the pawl support 262 .
- the pawl support 262 rotates with respect to the support axle 22 when the rotational force applied to the pawl support 262 becomes larger than the retaining or friction force between the ring portion 288 b of the slide spring 288 and the outer circumferential groove 262 a of the pawl support 262 .
- the clutch mechanism 38 further includes a one-way clutch 290 .
- the one-way clutch 290 is operatively disposed between the pawl support 262 and the right cup 132 of the output part 68 for transmitting the forward rotation of the crank axle 14 to the output part 68 .
- the one-way clutch 290 has a plurality of clutch pawls 292 pivotally supported on the clutch pawl mounting sections 274 a of the pawl support 262 .
- the clutch pawls 292 are biased radially outwardly by a plurality of pawl springs 294 for engaging inner peripheral clutch teeth 296 formed on the inter peripheral surface of the left side of the right cup 132 .
- the clutch pawls 292 transmit the forward rotation of the crank axle 14 to the right cup 132 and hence to the output part 68 .
- the control projections 284 are engaged with the control ends 264 b of the engagement pawls 264 while the planetary gear carrier 200 rotates in response to the forward rotation of the crank axle 14 .
- This rotation of the planetary gear carrier 200 is prevented from being transmitted to the right cup 132 of the output part 68 via the engagement pawls 264 .
- FIG. 6 the control projections 284 are engaged with the control ends 264 b of the engagement pawls 264 while the planetary gear carrier 200 rotates in response to the forward rotation of the crank axle 14 .
- This rotation of the planetary gear carrier 200 is prevented from being transmitted to the right cup 132 of the output part 68 via the engagement pawls 264 .
- this rotation of the planetary gear carrier 200 is transmitted to the pawl support 262 via the connections between the projections 280 of the planetary gear carrier 200 and the recesses 278 of the pawl support 262 , and then the rotation of the pawl support 262 is transmitted to the right cup 132 of the output part 68 via the one-way clutch 290 .
- the toothed part 260 is disposed on the output part 68 of the gear shifting mechanism 32 , while the pawl support 262 is movably attached to the planetary gear carrier 200 of the planetary gear unit 66 .
- the toothed part 260 can be disposed on the planetary gear carrier of the planetary gear unit 66 , while the pawl support 262 is movably attached to the output part 68 of the gear shifting mechanism 32 .
- the torque generated by the pedaling force in the forward rotational direction is transmitted in the following transmission passage: the crank arms 101 ⁇ the crank axle 14 ⁇ the first rotation transmitting member 16 ⁇ the second rotation transmitting member 20 ⁇ the third rotation transmitting member 26 ⁇ the gear shifting main body 32 b ⁇ the first gear member 76 ⁇ the second gear member 78 .
- the output torque of the motor 30 is transmitted in the following path: the reduction gear unit 34 ⁇ the torque transmitting member 70 ⁇ the one-way clutch 80 ⁇ the second gear member 78 .
- the second gear member 78 combines these two torques to transmit them to the front sprocket 28 .
- the forward rotation of the crank arms 101 is transmitted to the front sprocket 28 after being assisted by the motor 30 .
- the gear shifting main body 32 b the planetary gear unit 66 transmits the forward rotation of the crank axle 14 through a plurality of power transmission paths.
- This shifting operation for selecting one of the power transmission paths is conventionally well known in U.S. Pat. Nos. 6,607,465 and 7,682,283, for example. Thus, the detailed configurations will be omitted for the sake of brevity.
- the rearward rotation of the crank arms 101 is also transmitted to the front sprocket 28 to rotate the front sprocket 28 in the rearward rotational direction.
- the torque generated by the pedaling force in the rearward rotational direction is transmitted in the following transmission passage: the crank arms 101 ⁇ the crank axle 14 ⁇ the first rotation transmitting member 16 ⁇ the second rotation transmitting member 20 ⁇ the third rotation transmitting member 26 ⁇ the gear shifting main body 32 b ⁇ the first gear member 76 ⁇ the second gear member 78 ⁇ the front sprocket 28 .
- the clutch ring 242 is disengaged from the planetary gear carrier 200 no matter which of the power transmission paths is selected. Then, the rotation of the input part 64 is transmitted to the output part 68 through the following transmission path: the input part 64 ⁇ the pawls 249 ⁇ the first ring gear 202 ⁇ the planetary gear carrier 200 ⁇ the engagement pawls 264 ⁇ the right cup 132 ⁇ the output part 68 .
- the rearward rotation of the crank arms 101 is transmitted to the front sprocket 28 to rotate the front sprocket 28 in the rearward rotational direction, thereby operating the coaster brake 104 a of the rear hub 104 .
- the gear shifting main body 32 b includes the retaining member 286 that maintains the relative angular position between the support axle 22 and the pawl support 262 .
- the planetary gear carrier 200 and the pawl support 262 rotates together in the clockwise direction while maintaining the engagement pawls 264 at the release position.
- the planetary gear carrier 200 starts to rotate in the counter-clockwise direction in FIG. 6 . If the pawl support 262 starts to rotate together with the planetary gear carrier 200 in the counter-clockwise direction in FIG.
- the engagement pawls 264 do not engage with the toothed part 260 as shown in FIG. 6 .
- the retaining member 286 maintains the relative angular position between the support axle 22 and the pawl support 262 until the rotational force applied to the pawl support 262 becomes larger than the retaining or friction force between the slide spring 288 of the retaining member 286 and the pawl support 262 .
- the retaining member 286 allows the planetary gear carrier 200 to relatively rotate with respect to the pawl support 262 in response to the rearward rotation of the crank arms 101 , and prevents the pawl support 262 from rotating together with the planetary gear carrier 200 in the counter-clockwise direction until the positional relationship between the planetary gear carrier 200 and the pawl support 262 transitions from the positional relationship shown in FIG. 6 to the positional relationship shown in FIG. 7 .
- the engagement pawls 264 of the clutch mechanism 38 can be properly operated in response to the rearward rotation of the crank arms 101 .
- the gear shifting main body 32 b includes the slide spring 254 that maintains the relative angular position between the first and second sun gears 148 and 150 . While the crank arms 101 rotate in the forward rotational direction, the one-way clutch 250 engages the second ring gear 204 and the output part 68 . Furthermore, if the rotation of the crank arms 101 is stopped, the one-way clutch 250 still engages the second ring gear 204 and the output part 68 .
- the gear shifting mechanism 32 may be locked up since both of the clutch mechanism 38 and the one-way clutch 250 are engaged with the output part 68 .
- the slide spring 254 maintains the relative angular position between the first and second sun gears 148 and 150 until the rotational force applied to the second sun gear 150 becomes larger than the retaining or friction force between the slide spring 254 and the second sun gear 150 .
- the second planetary gears 208 is first rotated while the second sun gear 150 meshed with the second planetary gears 208 is stationary with respect to the first sun gear 148 , which also rotates the second ring gear 204 for disengaging the one-way clutch 250 .
- the engagement pawls 264 become engaged with the toothed part 260 of the right cup 132 of the output part 68 . Therefore, the slide spring 254 prevents both of the clutch mechanism 38 and the one-way clutch 250 from being engaged with the output part 68 in response to the rearward rotation of the crank arms 101 , which prevents the gear shifting mechanism 32 from being locked up.
- the coaster brake 104 a can be properly operated in response to the rearward rotation of the crank arms 101 .
- first rotation transmitting member 16 , the second rotation transmitting member 20 , and the third rotation transmitting member 26 can be made of any appropriate parts selected from the group of gears, sprockets, and pulleys.
- the bearings are ball bearings or needle-shaped roller bearings.
- any types of bearings that allow the members to be rotatably installed can be adopted.
- other types of roller bearings, as well as bushes or other sliding-type bearings can also be applied to the illustrated embodiment.
- the parts of the second embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment.
- the descriptions of the parts of the second embodiment that are substantially identical to the parts of the first embodiment may be omitted for the sake of brevity.
- the descriptions and illustrations of the first embodiment also apply to this second embodiment, except as discussed and/or illustrated herein.
- the drive unit 310 is arranged in a vicinity of the crank arms 101 (see FIG. 1 ).
- the drive unit 310 has a housing 312 , a crank axle 314 , a first rotation transmitting member 316 , an intermediate axle 318 , a second rotation transmitting member 320 , a support axle 322 , a second chain 324 , a third rotation transmitting member 326 and a front sprocket 328 (e.g., a sprocket).
- the crank axle 314 , the intermediate axle 318 and the support axle 322 are arranged to extend parallel to each other at spaced locations. As shown in FIG.
- the drive unit 310 has a motor 330 , a gear shifting mechanism 332 , a reduction gear unit 334 , a torque combining mechanism 336 , and a clutch mechanism 338 .
- the bicycle drive unit 310 includes the motor 330 , the crank axle 314 , the torque combining mechanism 336 , and the clutch mechanism 338 .
- the housing 312 , the crank axle 314 , the first rotation transmitting member 316 , the intermediate axle 318 , the second rotation transmitting member 320 , the support axle 322 , the second chain 324 , the third rotation transmitting member 326 , the motor 330 , the reduction gear unit 334 , the torque combining mechanism 336 are basically identical to the housing 12 , the crank axle 14 , the first rotation transmitting member 16 , the intermediate axle 18 , the second rotation transmitting member 20 , the support axle 22 , the second chain 24 , the third rotation transmitting member 26 , the motor 30 , the reduction gear unit 34 , the torque combining mechanism 36 in accordance with the first embodiment, except for minor changes.
- the detailed descriptions of these components will be omitted for the sake of brevity.
- the crank axle 314 is rotatable about a rotational axis X 1 (e.g., a first rotational axis).
- the motor 330 includes a crank axle receiving hole 330 a .
- the crank axle 314 is rotatably disposed in the crank axle receiving hole 330 a of the motor 330 .
- the gear shifting mechanism 332 is arranged on the power transmission passage between the third rotation transmitting member 326 and the torque combining mechanism 336 .
- the gear shifting mechanism 332 has a shifting motor unit 332 a.
- the gear shifting mechanism 332 has a gear shifting main body 332 b .
- the shifting motor unit 332 a rotates an actuating member of the gear shifting main body 332 b to a prescribed phase upon receiving a shift operation from a shifter installed on a handle of the bicycle.
- the shifting motor unit 332 a is identical to the shifting motor unit 32 a in accordance with the first embodiment. Thus, the detailed descriptions will be omitted for the sake of brevity.
- the gear shifting main body 332 b is a transmission unit that allows selection from a plurality of (e.g., 8) gear ratios.
- the configuration of the gear shifting main body 332 b is basically identical to a conventionally well-known transmission unit, such as a transmission unit disclosed in Japanese Utility Model Registration No. 3146138. Thus, the detailed descriptions will be omitted for the sake of brevity.
- the gear shifting main body 332 b of the gear shifting mechanism 332 includes the support axle 322 , an input part 344 , a planetary gear unit 346 , and an output part 348 .
- the rotation of the third rotation transmitting member 326 is transmitted to the input part 344 , the planetary gear unit 346 and the output part 348 .
- the input part 344 , the planetary gear unit 346 and the output part 348 are rotatably supported on the support axle 322 , respectively. Specifically, the input part 344 is rotatably supported on the support axle 322 and operatively coupled to the crank axle 314 .
- the third rotation transmitting member 326 is fixedly coupled to the input part 344 such that they can rotate together.
- the planetary gear unit 346 is disposed between the input part 344 and the output part 348 .
- the planetary gear unit 346 selectively establishes a plurality of (e.g., 8) gear ratios.
- the output part 348 is rotatably supported on the support axle 322 and operatively coupled to the torque combining mechanism 336 .
- the output part 348 outputs the rotation after changing the rotational speed by the planetary gear unit 346 to the torque combining mechanism 336 .
- the reduction gear unit 334 is also identical to the reduction gear unit 34 , except for first and second ring gears 372 d and 374 d are coupled to an inner peripheral surface of an axially extending portion of a motor case 356 .
- first and second ring gears 372 d and 374 d are coupled to an inner peripheral surface of an axially extending portion of a motor case 356 .
- the torque combining mechanism 336 is operatively coupled to the motor 330 and the crank axle 314 to combine rotational outputs of the motor 330 and the crank axle 314 .
- the torque combining mechanism 336 has a first gear member 376 fixedly coupled to the output part 348 of the gear shifting mechanism 332 , a second gear member 378 that meshes with the first gear member 376 , and a one-way clutch 380 .
- the torque combining mechanism 336 is operatively connected to a rotor 358 (e.g., a rotational output portion) of the motor 330 through the one-way clutch 380 to receive the rotational output of the motor 330 .
- the second gear member 378 is basically identical to the second gear member 78 , except that the front sprocket 328 is movably attached to the second gear member 378 . Thus, the detailed description will be omitted for the sake of brevity. As shown in FIG.
- the second gear member 378 of the torque combining mechanism 336 has a sprocket mounting portion 379 that is configured to be operatively attached to the front sprocket 328 (e.g., a sprocket) such that the front sprocket 328 rotates about the rotational axis X 1 (e.g., a second rotational axis of a sprocket) in the forward rotational direction (e.g., a first direction) as the crank axle 314 rotates about the rotational axis X 1 in the forward rotational direction.
- the front sprocket 328 e.g., a sprocket
- the front sprocket 328 rotates about the rotational axis X 1 (e.g., a second rotational axis of a sprocket) in the forward rotational direction (e.g., a first direction) as the crank axle 314 rotates about the rotational axis X 1 in the
- the clutch mechanism 338 is operatively disposed between the crank axle 314 and the front sprocket 328 .
- the clutch mechanism 338 is configured to rotate the front sprocket 328 about the rotational axis X 1 (e.g., a second rotational axis) in the rearward rotational direction (e.g., a second direction) as the crank axle 314 rotates about the rotational axis X 1 in the rearward rotational direction.
- the rearward rotational direction is opposite the forward rotational direction.
- the clutch mechanism 338 permits a relative rotation between the crank axle 314 and the front sprocket 328 in the forward rotational direction (e.g., the first direction).
- the clutch mechanism 338 is supported on the crank axle 314 between the crank axle 314 and the front sprocket 328 .
- the clutch mechanism 338 can also be supported on the front sprocket 328 or the torque combining mechanism 336 between the crank axle 314 and the front sprocket 328 .
- the clutch mechanism 338 includes a toothed part 360 (e.g., an internally toothed part), a pawl support 362 , a plurality of engagement pawls 364 , a plurality of biasing members 366 .
- the clutch mechanism 338 also includes a control part 368 .
- the toothed part 360 is disposed on the front sprocket 328 .
- the toothed part 360 is disposed on an inner peripheral surface 385 a of the front sprocket 328 .
- the toothed part 360 has a plurality of engagement teeth 360 a formed on the inner peripheral surface 385 a of the front sprocket 328 .
- the engagement teeth 360 a selectively engage with the engagement pawls 364 for transmitting the rearward rotation of the crank axle 314 to the front sprocket 328 .
- the pawl support 362 is fixedly coupled to the crank axle 314 .
- the pawl support 362 pivotally supports the engagement pawls 364 on an outer peripheral surface of the pawl support 362 in a conventional manner.
- the toothed part 360 is disposed on the front sprocket 328 , while the pawl support 362 is fixedly coupled to the crank axle 314 .
- the toothed part 360 can be disposed on the crank axle 314
- the pawl support 362 can be fixedly coupled to the front sprocket 328 .
- the toothed part 360 can be disposed on an outer peripheral surface of the crank axle 314 , while the pawl support 362 can be fixedly coupled to the inner peripheral surface 385 a the front sprocket 328 . Furthermore, the toothed part 360 can be disposed on one of the sprocket mounting portion 379 and the crank axle 314 , while the pawl support 362 can be fixedly coupled to the other of the sprocket mounting portion 379 and the crank axle 314 .
- the toothed part 360 can be disposed on one of the inner peripheral surface 385 a of the sprocket mounting portion 379 and the outer peripheral surface of the crank axle 314 , while the pawl support 362 can be fixedly coupled to the other of the inner peripheral surface 385 a of the sprocket mounting portion 379 and the outer peripheral surface of the crank axle 314 .
- the engagement pawls 364 are movably mounted to the pawl support 362 between a release position and an engagement position.
- Each of the engagement pawls 364 has an engagement end 364 a and a pivot end 364 b .
- the engagement ends 364 a of the engagement pawls 364 are engaged with the engagement teeth 360 a of the front sprocket 328 when the engagement pawls 364 are located at the engagement position, while the engagement ends 364 a of the engagement pawls 364 are disengaged from the engagement teeth 360 a of the front sprocket 328 when the engagement pawls 364 are moved towards the release position.
- the engagement pawls 364 are pivotally coupled to the pawl support 362 such that the engagement pawls 364 pivot about a pivot axis on the pivot end 364 b in a conventional manner.
- the biasing members 366 bias the engagement pawls 364 towards the engagement position, respectively.
- the biasing members 366 basically includes pawl springs operatively disposed between the engagement pawls 364 and the pawl support 362 .
- the control part 368 is disposed on an inner peripheral surface 379 a of the sprocket mounting portion 379 (e.g., an output member) of the torque combining mechanism 336 .
- the control part 368 selectively causes the engagement pawls 364 to engage with the toothed part 360 as the crank axle 314 rotates in the rearward rotational direction such that the clutch mechanism 338 transmits a rotation of the crank axle 314 to the front sprocket 328 .
- the control part 368 is aligned with the toothed part 360 as the crank axle 314 rotates in the forward rotational direction such that the engagement pawls 364 slide over the control part 368 and the toothed part 360 as the crank axle 314 rotates in the forward rotational direction.
- the control part 368 has a plurality of bumps 391 circumferentially arranged on the inner peripheral surface 379 a of the sprocket mounting portion 379 .
- Each of the bumps 391 has a slope surface 391 a .
- the slope surface 391 a is flatter than an engagement surface 360 b of each of the engagement teeth 360 a that engages with the engagement pawls 364 .
- the bumps 391 have a circumferential width in the circumferential direction that is larger than that of the engagement teeth 360 a.
- the front sprocket 328 has an annular section 383 that has the sprocket teeth formed on the outer peripheral portion, and a cylindrical section 385 integrally formed on the inner peripheral portion of the annular section 383 .
- the front sprocket 328 is movably attached to the inner peripheral surface 379 a of the sprocket mounting portion 379 .
- the front sprocket 328 rotates about the rotational axis X 1 of the crank axle 314 .
- the rotational axis of the crank axle 314 e.g., a first rotational axis
- the rotational axis of the front sprocket 328 e.g., a second rotational axis
- front sprocket 328 and the crank axle 314 can be arranged with respect to each other such that the rotational axes of the front sprocket 328 and the crank axle 314 are offset with respect to each other.
- the front sprocket 328 has the engagement teeth 360 a on the inner peripheral surface 385 a of the cylindrical section 385 .
- the front sprocket 328 has a plurality of projections 389 .
- the projections 389 are circumferentially arranged on an outer peripheral surface 385 b of the cylindrical section 385 .
- the sprocket mounting portion 379 of the torque combining mechanism 336 has a plurality of recesses 387 .
- the recesses 387 are circumferentially arranged on the inner peripheral surface 379 a of the sprocket mounting portion 379 .
- the recesses 387 and the projections 389 are arranged relative to each other with circumferential spacings therebetween, respectively, to provide a limited range of relative rotation between the sprocket mounting portion 379 of the torque combining mechanism 336 and the front sprocket 328 .
- FIGS. 13B to 13E and FIGS.
- the recesses 387 have first inside surfaces 387 a , respectively, that circumferentially contact with first contact surfaces 389 a of the projections 389 , respectively, as the crank axle 314 rotates in the forward rotational direction such that a rotation of the crank axle 314 in the forward rotational direction is transmitted from the sprocket mounting portion 379 of the torque combining mechanism 336 to the front sprocket 328 .
- the recesses 387 have second inside surfaces 387 b , respectively, that circumferentially contact with second contact surfaces 389 b of the projections 389 , respectively, while the crank axle 314 is stationary.
- FIGS. 13A and 13G the recesses 387 have second inside surfaces 387 b , respectively, that circumferentially contact with second contact surfaces 389 b of the projections 389 , respectively, while the crank axle 314 is stationary.
- the front sprocket 328 is circumferentially biased in the clockwise direction with respect to the sprocket mounting portion 379 with a biasing or return spring 393 . Furthermore, the front sprocket 328 is circumferentially biased with respect to the sprocket mounting portion 379 such that the engagement surface 360 b of each of the engagement teeth 360 a of the front sprocket 328 are disposed in the forward rotational direction of the crank axle 314 with respect to the slope surface 391 a of corresponding one of the bumps 391 of the sprocket mounting portion 379 while the crank axle 314 is stationary.
- the sprocket mounting portion 379 of the torque combining mechanism 336 has the recesses 387
- the front sprocket 328 has the projections 389
- the sprocket mounting portion 379 of the torque combining mechanism 336 can have a plurality of projections
- the front sprocket 328 can have a plurality of recesses.
- the recesses and the projections are arranged relative to each other with circumferential spacings therebetween, respectively, to provide a limited range of relative rotation between the sprocket mounting portion 379 of the torque combining mechanism 336 and the front sprocket 328 .
- the torque generated by the pedaling force in the forward rotational direction is transmitted in the following transmission passage: the crank arms 101 ⁇ the crank axle 314 ⁇ the first rotation transmitting member 316 ⁇ the second rotation transmitting member 320 ⁇ the third rotation transmitting member 326 ⁇ the gear shifting main body 332 b ⁇ the first gear member 376 ⁇ the second gear member 378 .
- the output torque of the motor 330 is transmitted in the following path: the reduction gear unit 334 ⁇ a torque transmitting member 370 ⁇ the one-way clutch 380 ⁇ the second gear member 378 .
- the second gear member 378 combines these two torques to transmit them to the front sprocket 328 .
- the front sprocket 328 is circumferentially biased with respect to the sprocket mounting portion 379 such that the second inside surfaces 387 b of the recesses 387 circumferentially contact with the second contact surfaces 389 b of the projections 389 , respectively. Furthermore, while the crank axle 314 is stationary, the engagement surface 360 b of each of the engagement teeth 360 a of the front sprocket 328 are disposed in the forward rotational direction of the crank axle 314 with respect to the slope surface 391 a of corresponding one of the bumps 391 of the sprocket mounting portion 379 .
- the second gear member 378 rotates in the clockwise direction with respect to the front sprocket 328 until the first inside surfaces 387 a of the recesses 387 circumferentially contact with the first contact surfaces 389 a of the projections 389 , respectively.
- the rotation of the second gear member 378 is transmitted to the front sprocket 328 , which rotate the second gear member 378 and the front sprocket 328 together in the forward rotational directions.
- the bumps 391 of the control part 368 and the engagement teeth 360 a of the toothed part 360 are arranged with respect to each other such that the bumps 391 of the control part 368 are axially aligned with engagement teeth 360 a of the toothed part 360 while the first inside surfaces 387 a of the recesses 387 circumferentially contact with the first contact surfaces 389 a of the projections 389 , respectively.
- the engagement pawls 364 slide over the bumps 391 of the control part 368 while pivoting between the engagement position and the release position as the crank axle 314 rotates in the forward rotational direction, which prevents the engagement pawls 364 from engaging with the engagement teeth 360 a of the toothed part 360 .
- the forward rotational speed of the second gear member 378 is faster than the forward rotational speed of the crank axle 314 while the speed ratio of the second gear member 378 relative to the crank axle 314 is larger than one due to a selection of the gear ratios of the gear shifting mechanism 332 .
- the engagement pawls 364 relatively slide over the bumps 391 of the control part 368 in the rearward rotational direction in order as illustrated in FIGS. 13H , 13 I, 13 J and 13 K.
- the forward rotational speed of the second gear member 378 is slower than the rotational speed of the crank axle 314 while the speed ratio of the second gear member 378 relative to the crank axle 314 is smaller than one due to a selection of the gear ratios of the gear shifting mechanism 332 .
- the engagement pawls 364 relatively slide over the bumps 391 of the control part 368 in the forward rotational direction in order as illustrated in FIGS. 13K , 13 J, 13 I and 13 H. Therefore, the clutch mechanism 338 allows a relative rotation between the crank axle 314 and the front sprocket 328 in the forward rotational direction.
- the rearward rotation of the crank arms 101 is also transmitted to the front sprocket 328 to rotate the front sprocket 328 in the rearward rotational direction.
- the torque generated by the pedaling force in the rearward rotational direction is transmitted in the following transmission passage: the crank arms 101 ⁇ the crank axle 314 ⁇ the clutch mechanism 338 ⁇ the front sprocket 328 .
- the rearward rotation of the crank arms 101 is not transmitted to the second gear member 378 via the gear shifting mechanism 332 by the operation of a one-way clutch disposed in the gear shifting mechanism 332 .
- the engagement surface 360 b of each of the engagement teeth 360 a of the front sprocket 328 are disposed in the forward rotational direction of the crank axle 314 with respect to the slope surface 391 a of corresponding one of the bumps 391 of the sprocket mounting portion 379 .
- crank axle 314 when crank axle 314 is rotated in the rearward rotational direction, the engagement ends 364 a of the engagement pawls 364 engage with the engagement surfaces 360 b of the engagement teeth 360 a of the front sprocket 328 , which rotates the front sprocket 328 in the rearward rotational direction together with the sprocket mounting portion 379 . Accordingly, the rearward rotation of the crank arms 101 is transmitted to the front sprocket 328 to rotate the front sprocket 328 in the rearward rotational direction, thereby operating the coaster brake 104 a of the rear hub 104 .
- the parts of the third embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment.
- the descriptions of the parts of the third embodiment that are substantially identical to the parts of the first embodiment may be omitted for the sake of brevity.
- the descriptions and illustrations of the first embodiment also apply to this third embodiment, except as discussed and/or illustrated herein.
- the drive unit 410 is arranged in a vicinity of the crank arms 101 (see FIG. 1 ).
- the drive unit 410 has a housing 412 , a crank axle 414 , a first rotation transmitting member 416 , an intermediate axle 418 , a second rotation transmitting member 420 , a third rotation transmitting member 426 and a front sprocket 428 (e.g., a sprocket).
- the drive unit 410 has a motor 430 , a torque combining mechanism 436 , and a clutch mechanism 438 .
- the bicycle drive unit 410 includes the motor 430 , the crank axle 414 , the torque combining mechanism 436 , and the clutch mechanism 438 .
- crank axle 414 and the front sprocket 428 are identical to the crank axle 314 and the front sprocket 328 in accordance with the second embodiment.
- the clutch mechanism 438 is identical to the clutch mechanism 338 in accordance with the second embodiment, except that parts of the clutch mechanism 438 corresponding to parts of the clutch mechanism 338 that are disposed on the sprocket mounting portion 379 are disposed on a sprocket mounting portion 479 that is fixedly coupled to an axially extending sleeve 444 of the torque combining mechanism 436 .
- the housing 412 mainly accommodates the first rotation transmitting member 416 , the intermediate axle 418 , the second rotation transmitting member 420 , the third rotation transmitting member 426 , the motor 430 , and the torque combining mechanism 436 .
- the housing 412 also rotatably supports the crank axle 414 by a pair of bearings in a conventional manner.
- the crank axle 414 extends through the housing 412 .
- the crank axle 414 is rotatable about a rotational axis X 1 (e.g., a first rotational axis).
- the first rotation transmitting member 416 has a first gear 416 a that is fixedly coupled to the crank axle 414 .
- the intermediate axle 418 is rotatably supported inside the housing 412 by a pair of bearings.
- the second rotation transmitting member 420 has a large gear 420 a and a small gear 420 b .
- the third rotation transmitting member 426 has a third gear 426 a .
- the front sprocket 428 (e.g., a sprocket) is identical to the front sprocket 328 in accordance with the second embodiment.
- the front sprocket 428 rotates about the rotational axis X 1 of the crank axle 414 .
- the rotational axis of the crank axle 414 e.g., a first rotational axis
- the rotational axis of the front sprocket 428 e.g., a second rotational axis
- the motor 430 is an inner rotor-type motor.
- the motor 430 has a rotor 430 a and a stator 430 b . Since the motor 430 has a conventional configuration, the detailed description will be omitted for the sake of brevity.
- the stator 430 b is fixedly coupled to an inner side surface of the housing 412 .
- the rotor 430 a is fixedly coupled to a drive shaft 430 c of the motor 430 .
- the drive shaft 430 c is rotatably supported relative to the housing by a pair of bearings.
- the third gear 426 a of the third rotation transmitting member 426 is fixedly coupled to a distal end of the drive shaft 430 c of the motor 430 .
- the third gear 426 a also meshes with the large gear 420 a of the second rotation transmitting member 420 .
- the large gear 420 a is rotatably coupled to the intermediate axle 418 via a one-way clutch 440 .
- the one-way clutch 440 only transmits rotational output of the motor 430 for the forward rotation of the front sprocket 428 to the intermediate axle 418 .
- the small gear 420 b is fixedly coupled to the intermediate axle 418 .
- the torque combining mechanism 436 is operatively coupled to the motor 430 and the crank axle 414 to combine rotational outputs of the motor 430 and the crank axle 414 .
- the torque combining mechanism 436 has a casing portion 442 and an axially extending sleeve 444 .
- the torque combining mechanism 436 is rotatably supported on the crank axle 414 by a bearing.
- the casing portion 442 has an outer gear 446 on an outer peripheral surface of the casing portion 442 .
- the outer gear 446 meshes with the small gear 420 b of the second rotation transmitting member 420 .
- the casing portion 442 is rotatably coupled to the first rotation transmitting member 416 via a one-way clutch 448 .
- the one-way clutch 448 is disposed between to an inner peripheral surface of the casing portion 442 and the first gear 416 a of the first rotation transmitting member 416 .
- the one-way clutch 448 only transmits the forward rotation of the crank axle 414 to the casing portion 442 of the torque combining mechanism 436 .
- the torque combining mechanism 436 combines the rotational output of the motor 430 transmitted to the outer gear 446 of the casing portion 442 and the rotational output of the crank axle 414 transmitted from the first gear 416 a via the one-way clutch 448 .
- the axially extending sleeve 444 has a torque sensor 450 with a pair of magnetic deflection elements 450 a and a pair of coils 450 b that radially face with each other, respectively.
- the torque detected by the torque sensor 450 is used to control the rotational output of the motor 430 .
- the torque sensor 450 can be other type of torque sensors.
- the sprocket mounting portion 479 is configured to be operatively attached to the front sprocket 428 (e.g., a sprocket) such that the front sprocket 428 rotates about the rotational axis X 1 (e.g., a second rotational axis of a sprocket) in the forward rotational direction (e.g., a first direction) as the crank axle 414 rotates about the rotational axis X 1 in the forward rotational direction.
- the sprocket mounting portion 479 is fixedly coupled to a distal end of the axially extending sleeve 444 such that sprocket mounting portion 479 rotates together with the torque combining mechanism 436 .
- the sprocket mounting portion 479 is identical to the sprocket mounting portion 379 in accordance with the second embodiment. Thus, the detailed configuration will be omitted for the sake of brevity.
- the clutch mechanism 438 is operatively disposed between the crank axle 414 and the front sprocket 428 .
- the clutch mechanism 438 is configured to rotate the front sprocket 428 about the rotational axis X 1 (e.g., a second rotational axis) in the rearward rotational direction (e.g., a second direction) as the crank axle 414 rotates about the rotational axis X 1 in the rearward rotational direction.
- the rearward rotational direction is opposite the forward rotational direction.
- the torque generated by the pedaling force in the forward rotational direction is transmitted in the following transmission passage: the crank arms 101 ⁇ the crank axle 414 ⁇ the first rotation transmitting member 416 ⁇ the one-way clutch 448 ⁇ the torque combining mechanism 436 .
- the output torque of the motor 430 is transmitted in the following path: the third rotation transmitting member 426 ⁇ the second rotation transmitting member 420 ⁇ the torque combining mechanism 436 .
- the torque combining mechanism 436 combines these two torques to transmit them to the front sprocket 428 via the sprocket mounting portion 479 .
- the forward rotation of the crank arms 101 is transmitted to the front sprocket 428 after being assisted by the motor 430 .
- the torque transmission from the sprocket mounting portion 479 to the front sprocket 428 is identical to the torque transmission from the sprocket mounting portion 379 to the front sprocket 328 in accordance with the second embodiment. Thus, the detailed description will be omitted for the sake of brevity.
- the rearward rotation of the crank arms 101 is also transmitted to the front sprocket 428 to rotate the front sprocket 428 in the rearward rotational direction.
- the torque generated by the pedaling force in the rearward rotational direction is transmitted in the following transmission passage: the crank arms 101 ⁇ the crank axle 414 ⁇ the clutch mechanism 438 ⁇ the front sprocket 428 .
- the rearward rotation of the crank arms 101 is not transmitted to the casing portion 442 of the torque combining mechanism 436 via the first rotation transmitting member 416 by the operation of the one-way clutch 448 .
- the torque transmission from the clutch mechanism 438 to the front sprocket 428 is identical to the torque transmission from the clutch mechanism 338 to the front sprocket 328 in accordance with the second embodiment. Thus, the detailed description will be omitted for the sake of brevity.
- the parts of the fourth embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment.
- the descriptions of the parts of the fourth embodiment that are substantially identical to the parts of the first embodiment may be omitted for the sake of brevity.
- the descriptions and illustrations of the first embodiment also apply to this fourth embodiment, except as discussed and/or illustrated herein.
- the drive unit 10 in accordance with the first embodiment includes the gear shifting mechanism 32 and the clutch mechanism 38 that transmit the rotation of the input part 64 caused by the forward rotation of the crank axle 14 to the output part 68 such that the front sprocket 28 rotates in the forward rotational direction.
- the gear shifting mechanism 32 and the clutch mechanism 38 also transmit the rotation of the input part 64 caused by the rearward rotation of the crank axle 14 to the output part 68 such that the front sprocket rotates in the rearward rotational direction.
- the drive unit in accordance with the present application can include any types of gear shifting mechanisms and the clutch mechanism having the above-mentioned feature. For example, as shown in FIG.
- the drive unit 510 in accordance with the fourth embodiment has a gear shifting mechanism 532 and the clutch mechanism 538 .
- This gear shifting mechanism 532 and the clutch mechanism 538 is basically identical to the internally mounted hub transmission disclosed in European Patent No. EP 1 700 780 B1, except that the gear shifting mechanism 532 and the clutch mechanism 538 are installed in the drive unit 510 .
- the drive unit 510 is also identical to the drive unit 10 shown in FIG. 2 , except that the drive unit 510 has the gear shifting mechanism 532 and the clutch mechanism 538 instead of the gear shifting mechanism 32 and the clutch mechanism 38 .
- This gear shifting mechanism 532 and the clutch mechanism 538 selectively establishes three gear ratios for the forward rotation of the front sprocket 28 and one gear ratio of the rearward rotation of the front sprocket 28 .
- the gear shifting mechanism 532 mainly includes a support axle 522 , an input part 564 , a planetary gear unit 566 , and an output part 568 .
- the rotation of the third rotation transmitting member 26 (see FIG. 2 ) is transmitted to the input part 564 , the planetary gear unit 566 and the output part 568 .
- the input part 564 , the planetary gear unit 566 and the output part 568 are rotatably supported on the support axle 522 , respectively.
- the input part 564 is rotatably supported on the support axle 522 and operatively coupled to the crank axle 14 (see FIG. 2 ).
- the second sprocket 26 a of the third rotation transmitting member 26 (see FIG. 2 ) is fixedly coupled to the input part 564 such that they can rotate together.
- the planetary gear unit 566 is disposed between the input part 564 and the output part 568 .
- the planetary gear unit 566 selectively establishes a plurality of (e.g., three) gear ratios.
- the planetary gear unit 566 transmits power between the input part 564 and the output part 568 .
- the output part 568 is rotatably supported on the support axle 522 and operatively coupled to the torque combining mechanism 36 (see FIG. 2 ).
- the output part 568 outputs the rotation after changing the rotational speed by the planetary gear unit 566 to the torque combining mechanism 36 (see FIG. 2 ).
- the first gear member 76 of the torque combining mechanism 36 (see FIG. 2 ) is coupled to the output part 568 .
- the gear shifting mechanism 532 further has a roller brake 577 , which itself is known as a coaster brake unit.
- a roller brake 577 which itself is known as a coaster brake unit.
- the drive unit 510 further has a clutch mechanism 538 that is operatively disposed between the crank axle 14 and the front sprocket 28 (see FIG. 2 ).
- the clutch mechanism 538 is configured to rotate the front sprocket 28 in the rearward rotational direction as the crank axle 14 rotates in the rearward rotational direction.
- the clutch mechanism 538 is supported to the support axle 522 of the gear shifting mechanism 532 such that the clutch mechanism 538 is operatively disposed between a planetary gear carrier 566 a of the planetary gear unit 566 and the output part 568 of the gear shifting mechanism 532 .
- FIG. 1 As shown in FIG.
- a brake cup 580 carries the roller brake 577 , an inner free gear 582 , an outer free gear 584 , and a one-way clutch 586 between the inner and outer free gears 582 and 584 , which form the clutch mechanism 538 .
- the outer free gear 584 is fixedly coupled to the housing 12 (see FIG. 2 ).
- the one-way clutch 586 is configured to transmit a rearward rotational force from the brake cup 580 to the outer free gear 584 .
- the roller brake 577 transmits the rearward rotational power to the output part 568 such that the front sprocket 28 rotates in the rearward rotational direction.
- the gear shifting mechanism 32 and 532 have eight and three speed transmission units, respectively. However, they can be replaced by a two, five, seven, nine or eleven speed transmission unit.
- Coupled encompasses configurations in which an element is directly secured to another element by affixing the element directly to the other element; configurations in which the element is indirectly secured to the other element by affixing the element to the intermediate member(s) which in turn are affixed to the other element; and configurations in which one element is integral with another element, i.e. one element is essentially part of the other element.
- This definition also applies to words of similar meaning, for example, “joined”, “connected”, “attached”. “mounted”, “bonded”, “fixed” and their derivatives.
- first and second may be used herein to describe various components these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, for example, a first component discussed above could be termed a second component and vice-a-versa without departing from the teachings of the present invention. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. 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.
Abstract
Description
- 1. Field of the Invention
- The present invention generally relates to a bicycle drive unit. In particular, the present invention relates to a drive unit for an electrically assisted bicycle.
- 2. Background Information
- A coaster brake is conventionally known that is disposed on a bicycle (see European Patent Application Publication No. 2 380 806 A2 (Patent Citation 1) and Japanese Patent No. 4959858 (Patent Citation 2), for example). Generally, a bicycle crank arm and a front gear are non-rotatably coupled to each other. The coaster brake is disposed on a bicycle rear hub, and is operatively coupled to the front gear. Thus, when the bicycle crank arm is rotated in a rearward rotational direction, the coaster brake is operated.
- On the other hand, an electrically assisted bicycle is conventionally known that uses a motor output as assisting power (see Japanese Laid-Open Patent Application Publication No. H08-310478 (Patent Citation 3), for example). In the electrically assisted bicycle, after a pedaling force which is inputted by the pedals is transmitted and the transmitted drive force is combined with a drive force from the motor, the combined drive force is transmitted to the rear wheel, thereby causing the rear wheel to rotate.
- It has been discovered that a coaster brake can not be merely applied to the electrically assisted bicycle. In particular, the Patent Citation 3 discloses a one-way clutch disposed between a crank arm and a front gear. The one-way clutch prevents a rotation of the crank arm in response to a rotation of an electric motor. However, it has been discovered that when the crank arm is rotated in a rearward rotational direction, the front gear does not rotate. Thus, even if the coaster brake is applied to the electrically assisted bicycle, the coaster brake can not be operated.
- One aspect is to provide a bicycle drive unit that can be utilized with a bicycle coaster brake.
- In accordance with a first aspect, a bicycle drive unit includes a motor, a crank axle, a torque combining mechanism, and a clutch mechanism. The crank axle is rotatable about a first rotational axis. The torque combining mechanism is operatively coupled to the motor and the crank axle to combine rotational outputs of the motor and the crank axle. The torque combining mechanism has a sprocket mounting portion that is configured to be operatively attached to a sprocket such that the sprocket rotates about a second rotational axis of the sprocket in a first direction as the crank axle rotates about the first rotational axis in the first direction. The clutch mechanism is operatively disposed between the crank axle and the sprocket. The clutch mechanism is configured to rotate the sprocket about the second rotational axis in a second direction as the crank axle rotates about the first rotational axis in the second direction. The second direction is opposite the first direction.
- In accordance with a second aspect, with the bicycle drive unit according to the first aspect, the first and second rotational axes are coincident with each other.
- In accordance with a third aspect, with the bicycle drive unit according to the first aspect, the clutch mechanism permits a relative rotation between the crank axle and the sprocket in the first direction.
- In accordance with a fourth aspect, the bicycle drive unit according to the first aspect further includes a gear shifting mechanism. The gear shifting mechanism includes a support axle, an input part, an output part, a planetary gear unit. The input part is rotatably supported on the support axle and operatively coupled to the crank axle. The output part is rotatably supported on the support axle and operatively coupled to the torque combining mechanism. The planetary gear unit is disposed between the input part and the output part.
- In accordance with a fifth aspect, with the bicycle drive unit according to the fourth aspect, the clutch mechanism is supported to the support axle of the gear shifting mechanism such that the clutch mechanism is operatively disposed between a planetary gear carrier of the planetary gear unit and the output part of the gear shifting mechanism.
- In accordance with a sixth aspect, with the bicycle drive unit according to the fifth aspect, the clutch mechanism includes a toothed part, a pawl support, an engagement pawl, and a biasing member. The toothed part is disposed on one of the output part of the gear shifting mechanism and the planetary gear carrier of the planetary gear unit. The pawl support is movably attached to the other of the output part of the gear shifting mechanism and the planetary gear carrier of the planetary gear unit. The engagement pawl is movably mounted to the pawl support between a release position and an engagement position. The biasing member biases the engagement pawl towards the engagement position.
- In accordance with a seventh aspect, with the bicycle drive unit according to the fifth aspect, the clutch mechanism includes an internally toothed part, a pawl support, an engagement pawl, a biasing member, and a control part. The internally toothed part is disposed on an inner peripheral surface of the output part of the gear shifting mechanism. The pawl support is movably attached to the planetary gear carrier of the planetary gear unit. The engagement pawl is movably mounted to the pawl support between a release position and an engagement position. The biasing member biases the engagement pawl towards the engagement position. The control part is disposed on an outer peripheral surface of the planetary gear carrier of the planetary gear unit. The control part selectively causes the engagement pawl to engage with the toothed part as the crank axle rotates in the second direction such that the clutch mechanism transmits a rotation of the crank axle to the output part of the gear shifting mechanism.
- In accordance with an eighth aspect, with the bicycle drive unit according to the sixth aspect, the pawl support has one of a recess and a projection disposed in a circumferential direction of the pawl support. The planetary gear carrier of the planetary gear unit has the other of recess and a projection located in the recess. The recess and the projection are arranged relative to each other with circumferential spacing therebetween to provide a limited range of relative rotation between the pawl support and the planetary gear carrier.
- In accordance with a ninth aspect, with the bicycle drive unit according to the eighth aspect, the projection has a contact surface that circumferentially contacts with an inside surface of the recess as the crank axle rotates in the first direction such that the rotation of the crank axle in the first direction is transmitted from the planetary gear carrier of the planetary gear unit to the output part of the gear shifting mechanism.
- In accordance with a tenth aspect, with the bicycle drive unit according to the sixth aspect, the clutch mechanism further includes a retaining member operatively disposed between the support axle and the pawl support. The retaining member maintains relative angular position between the pawl support and the support axle before the engagement pawl engages with the output part.
- In accordance with an eleventh aspect, with the bicycle drive unit according to the tenth aspect, the retaining member of the clutch mechanism further includes a slide spring having a leg portion and a ring portion. The leg portion is non-rotatably coupled to the support axle of the gear shifting mechanism. The ring portion extends from the leg portion and is disposed in an outer circumferential groove of the pawl support of the clutch mechanism.
- In accordance with a twelfth aspect, with the bicycle drive unit according to the fourth aspect, the planetary gear unit includes first and second sun gears that are operatively connected by a slide spring.
- In accordance with a thirteenth aspect, with the bicycle drive unit according to the twelfth aspect, the slide spring has a leg portion and a ring portion. The leg portion is disposed in a receiving hole of the first sun gear. The ring portion extends from the leg portion and is disposed in an inner circumferential groove of the second sun gear.
- In accordance with a fourteenth aspect, with the bicycle drive unit according to the first aspect, the clutch mechanism is supported on one of the crank axle, the sprocket and the torque combining mechanism between the crank axle and the sprocket.
- In accordance with a fifteenth aspect, the bicycle drive unit according to the fourteenth aspect further includes a gear shifting mechanism. The gear shifting mechanism includes a support axle, an input part, an output part, and a planetary gear unit. The input part is rotatably supported on the support axle and is operatively coupled to the crank axle. The output part is rotatably supported on the support axle and is operatively coupled to the torque combining mechanism. The planetary gear unit is disposed between the input part and the output part.
- In accordance with a sixteenth aspect, with the bicycle drive unit according to the fourteenth aspect, the clutch mechanism includes a toothed part, a pawl support, an engagement pawl, and a biasing member. The toothed part is disposed on one of the sprocket mounting portion and the crank axle. The pawl support is fixedly coupled to the other of the sprocket mounting portion and the crank axle. The engagement pawl is movably mounted to the pawl support between a release position and an engagement position. The biasing member biases the engagement pawl towards the engagement position.
- In accordance with a seventeenth aspect, with the bicycle drive unit according to the fourteenth aspect, the clutch mechanism includes a toothed part, a pawl support, an engagement pawl, and a biasing member. The toothed part is disposed on one of the sprocket and the crank axle. The pawl support is fixedly coupled to the other of the sprocket and the crank axle. The engagement pawl is movably mounted to the pawl support between a release position and an engagement position. The biasing member biases the engagement pawl towards the engagement position.
- In accordance with an eighteenth aspect, with the bicycle drive unit according to the fourteenth aspect, the clutch mechanism includes an internally toothed part, a pawl support, an engagement pawl, a biasing member, and a control part. The internally toothed part is disposed on an inner peripheral surface of the sprocket. The pawl support is fixedly coupled to the crank axle. The engagement pawl is movably mounted to the pawl support between a release position and an engagement position. The biasing member biases the engagement pawl towards the engagement position. The control part is disposed on an inner peripheral surface of an output member of the torque combining mechanism. The control part selectively causes the engagement pawl to engage with the toothed part as the crank axle rotates in the second direction such that the clutch mechanism transmits a rotation of the crank axle to the sprocket.
- In accordance with a nineteenth aspect, with the bicycle drive unit according to the eighteenth aspect, the control part is aligned with the toothed part as the crank axle rotates in the first direction such that the engagement pawl slides over the control part and the toothed part as the crank axle rotates in the first direction.
- In accordance with a twentieth aspect, with the bicycle drive unit according to the fourteenth aspect, the sprocket mounting portion of the torque combining mechanism has one of a recess and a projection. The sprocket has the other of the recess and the projection. The recess and the projection are arranged relative to each other with circumferential spacing therebetween to provide a limited range of relative rotation between the sprocket mounting portion of the torque combining mechanism and the sprocket.
- In accordance with a twenty-first aspect, with the bicycle drive unit according to the twentieth aspect, the recess has an inside surface that circumferentially contacts with a contact surface of the projection as the crank axle rotates in the first direction such that a rotation of the crank axle in the first direction is transmitted from the sprocket mounting portion of the torque combining mechanism to the sprocket.
- In accordance with a twenty-second aspect, with the bicycle drive unit according to the first aspect, the motor includes a crank axle receiving hole. The crank axle is rotatably disposed in the crank axle receiving hole of the motor.
- In accordance with a twenty-third aspect, with the bicycle drive unit according to the first aspect, the torque combining mechanism is operatively connected to a rotational output portion of the motor through a one-way clutch to receive the rotational output of the motor.
- Referring now to the attached drawings which form a part of this original disclosure:
-
FIG. 1 is a side elevational view of a drive train of an electrically assisted bicycle that is equipped with a drive unit in accordance with a first embodiment; -
FIG. 2 is a cross-sectional view illustrating the drive unit in accordance with the first embodiment, taken along II-II line inFIG. 1 ; -
FIG. 3 is an enlarged cross-sectional view of a gear shifting mechanism of the drive unit illustrated inFIG. 2 ; -
FIG. 4 is an exploded perspective view of a clutch mechanism of the drive unit illustrated inFIG. 2 ; -
FIG. 5 is an exploded perspective view of first and second sun gears of the gear shifting mechanism of the drive unit illustrated inFIG. 2 ; -
FIG. 6 is a cross-sectional view illustrating the clutch mechanism of the drive unit illustrated inFIG. 2 , taken along VI-VI line inFIG. 3 , with an engagement pawl disengaged from an internally toothed part; -
FIG. 7 is a cross-sectional view illustrating the clutch mechanism of the drive unit illustrated inFIG. 2 , taken along VII-VII line inFIG. 3 , with the engagement pawl engaged with the internally toothed part; -
FIG. 8 is an elevational view of a slide spring disposed between first and second sun gears of the gear shifting mechanism illustrated inFIG. 5 , illustrating an unloaded state of the slide spring; -
FIG. 9 is a cross-sectional view of the slide spring illustrated inFIG. 8 ; -
FIG. 10 is an elevational view of a slide spring of the clutch mechanism illustrated inFIG. 4 , illustrating a loaded state of the slide spring; -
FIG. 11 is a top plan view of the slide spring illustrated inFIG. 10 , illustrating an unloaded state of the slide spring; -
FIG. 12 is a cross-sectional view illustrating a drive unit in accordance with a second embodiment: -
FIG. 13A is an elevational view of a clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which a crank axle is stationary; -
FIG. 13B is an elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which a sprocket mounting portion start to rotate from an initial position in a forward rotational direction while a crank axle rotates in the forward rotational direction; -
FIG. 13C is an elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by five degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction; -
FIG. 13D is an elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by twenty degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction; -
FIG. 13E is an elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by twenty-five degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction; -
FIG. 13F is an elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the crank axle is stopped and the crank axle is rotated in a rearward direction; -
FIG. 13G is a partial elevational view of a clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the crank axle is stationary; -
FIG. 13H is a partial elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the sprocket mounting portion start to rotate from the initial position in the forward rotational direction while the crank axle rotates in the forward rotational direction; -
FIG. 13I is a partial elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by five degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction; -
FIG. 13J is a partial elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by twenty degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction; -
FIG. 13K is a partial elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the sprocket mounting portion rotate from the initial position by twenty-five degrees in the forward rotational direction while the crank axle rotates in the forward rotational direction; -
FIG. 13L is a partial elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the crank axle is stopped and the crank axle is rotated in a rearward direction; -
FIG. 13M is a partial elevational view of the clutch mechanism of the drive unit illustrated inFIG. 12 , illustrating a state in which the crank axle is further rotated in the rearward direction; -
FIG. 14 is a cross-sectional view illustrating a drive unit in accordance with a third embodiment; and -
FIG. 15 is a cross-sectional view illustrating a drive unit in accordance with a fourth embodiment. - Selected embodiments will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
- Referring initially to
FIGS. 1 and 2 , adrive unit 10 is illustrated in accordance with a first embodiment. As illustrated inFIG. 1 , thedrive unit 10 is disposed on adrive train 11 of an electrically assisted bicycle. In the illustrated embodiment,FIG. 1 only illustrates portions related to thedrive train 11 of the electrically assisted bicycle since other portions of the electrically assisted bicycle can be conventional. Thus, detailed description of the electrically assisted bicycle will be omitted for the sake of brevity. As illustrated inFIG. 1 , thedrive train 11 basically includes a pair ofpedals 100, a pair of crankarms 101, thedrive unit 10, afirst chain 102, arear sprocket 103 and arear hub 104. Thepedals 100 are rotatably mounted to the free ends of thecrank arms 101, respectively. The inner ends of thecrank arms 101 are fixed to opposite ends of a crank axle 14 (seeFIG. 2 ) of thedrive unit 10, respectively. The first chain is operatively connected between thedrive unit 10 and therear sprocket 103. For thedrive train 11 of the electrically assisted bicycle, pedaling force acting on thepedals 100 is transmitted to therear hub 104 that is rotatably coupled to arear hub axle 105 to rotate a rear wheel (not shown) of the electrically assisted bicycle via the following transmission passage: the crankarms 101→thedrive unit 10→thefirst chain 102 therear sprocket 103→therear hub 104. While transmitting the pedaling force, thedrive unit 10 synthesizes a motor output torque as an assisting power for assisting the pedaling force. In the illustrated embodiment, when a pedaling force more than a prescribed threshold is detected, then the motor output torque corresponding to the pedaling force is generated as the assisting power. Thedrive unit 10 is usually arranged in a vicinity of a connecting section between a seat tube (not shown) of a bicycle frame and a down tube (not shown) of the bicycle frame. A battery for thedrive unit 10 is arranged along a rear carrier, the down tube or the seat tube. - In the illustrated embodiment, the
rear hub 104 is equipped with acoaster brake 104 a. Thecoaster brake 104 a is operated for generating a braking force to the rear wheel via therear hub 104 in response to a rearward rotation of thecrank arms 101. In particular, in the illustrated embodiment, thecoaster brake 104 a of therear hub 104 is operated in response to the rearward rotation of thecrank arms 101 via thedrive unit 10, thefirst chain 102 and therear sprocket 103. Since coaster brakes are conventionally well known, the detailed description will be omitted for the sake of brevity. - As illustrated in
FIG. 1 , thedrive unit 10 is arranged in a vicinity of thecrank arms 101. In the illustrated embodiment, as shown inFIG. 2 , thedrive unit 10 has ahousing 12, a crank axle 14, a firstrotation transmitting member 16, anintermediate axle 18, a secondrotation transmitting member 20, asupport axle 22, asecond chain 24, a thirdrotation transmitting member 26 and a front sprocket 28 (e.g., a sprocket). In the illustrated embodiment, the crank axle 14, theintermediate axle 18 and thesupport axle 22 are arranged to extend parallel to each other at spaced locations. As shown inFIG. 2 , thedrive unit 10 has amotor 30, agear shifting mechanism 32, areduction gear unit 34, atorque combining mechanism 36, and aclutch mechanism 38. Thus, thebicycle drive unit 10 includes themotor 30, the crank axle 14, thetorque combining mechanism 36, and theclutch mechanism 38. - As shown in
FIG. 2 , thehousing 12 accommodates the firstrotation transmitting member 16, the secondrotation transmitting member 20, the thirdrotation transmitting member 26, themotor 30, thegear shifting mechanism 32, thereduction gear unit 34, thetorque combining mechanism 36, and theclutch mechanism 38. - The
housing 12 is a member made of, for example, aluminum or another metal. However, a part or the entire of thehousing 12 can also be made of a synthetic resin. Thehousing 12 has afirst side wall 12 a and asecond side wall 12 b. Thefirst side wall 12 a and thesecond side wall 12 b are independently formed as separate parts, and face with each other in an axial direction of the crank axle 14. Thehousing 12 has a housing main body containing thesecond side wall 12 b and a lid member containing thefirst side wall 12 a. The lid member is anchored detachably on the opening of the housing main body by bolts or other anchoring members to form an accommodating space for accommodating the firstrotation transmitting member 16, the secondrotation transmitting member 20, the thirdrotation transmitting member 26, themotor 30, thegear shifting mechanism 32, thereduction gear unit 34, thetorque combining mechanism 36, and theclutch mechanism 38. Thefirst side wall 12 a has a first side wall main body 12 c and afirst plate member 12 d. Thefirst plate member 12 d is installed detachably and non-rotatably on thefirst engagement hole 12 e formed on the first side wall main body 12 c. Thesecond side wall 12 b has a second side wall main body 12 f. - The
first plate member 12 d is made of a metal material different from the first side wall main body 12 c. Of course, alternatively, they can be made of the same material as the first side wall main body 12 c. Thefirst plate member 12 d is installed detachably from the outer side of thehousing 12 on the first side wall main body 12 c. Thefirst plate member 12 d is formed here as a round plate, with serrations and flanges for engagement with thefirst engagement hole 12 e formed on their outer peripheral portions. The serrations of thefirst plate member 12 d are engaged with thefirst engagement hole 12 e. The flange of thefirst plate member 12 d contacts with the side surface of the first side wall main body 12 c. On thefirst engagement hole 12 e, serration grooves for engaging with the serrations of thefirst plate member 12 d are formed. With this configuration, thefirst plate member 12 d is non-rotatably coupled to the first side wall main body 12 c. - The
housing 12 has a pair of round shaped first holes 13 a and 13 b, a pair ofsecond holes first holes second bearings first holes - The
second holes first plate member 12 d and the second wall main body 12 f. In thesecond holes support axle 22 is non-rotatably arranged in thesecond holes first plate member 12 d is detachably coupled to the first side wall main body 12 c. Of course, alternatively, thefirst plate member 12 d can be pressed in and integrated with the first side wall main body 12 c. - The crank axle 14 is a metal axle member made of, for example, iron, stainless steel, or the like. The crank axle 14 is rotatable about a rotational axis X1 (e.g., a first rotational axis). The crank axle 14 is rotatably supported by the
first bearing 39 a and thesecond bearing 39 b. The two ends of the crank axle 14 are arranged to protrude out from thefirst side wall 12 a and thesecond side wall 12 b, respectively. On the end portions of the crank axle 14, the crankarms 101 are detachably and non-rotatably coupled to the crank axle 14. In the end portion of the crank axle 14 on the first side wall main body 12 c side, the crank axle 14 has a large-diameter flange section 14 a for positioning the firstrotation transmitting member 16 in the axial direction and aserration section 14 b for connecting with the firstrotation transmitting member 16. The large-diameter flange section 14 a and theserration section 14 b are arranged adjacent to each other. Theflange section 14 a is formed on the entire circumference in the circumferential direction of the crank axle 14. Of course, alternatively, theflange section 14 a can be formed intermittently in the circumferential direction and protruding out from the crank axle 14. - The first
rotation transmitting member 16 is non-rotatably coupled to the crank axle 14 such that the firstrotation transmitting member 16 transmits the rotation of thecrank arms 101. The firstrotation transmitting member 16 has afirst gear 16 a made of, for example, a synthetic resin or a metal. Thefirst gear 16 a is connected to theserration section 14 b of the crank axle 14 such that thefirst gear 16 a and the crank axle 14 rotate together. Thefirst gear 16 a is fastened to the crank axle 14 by press-fit, bonding or another appropriate fastening manner. Thefirst gear 16 a makes contact with theflange section 14 a of the crank axle 14 such that thefirst gear 16 a is positioned in the axial direction of the crank axle 14. Thefirst gear 16 a is rotatably supported to thehousing 12 via thefirst bearing 39 a. The crank axle 14 is rotatably supported to thehousing 12 via thefirst bearing 39 a and thefirst gear 16 a. - The
intermediate axle 18 is an axle member made of iron, stainless steel or another metal. Theintermediate axle 18 has first andsecond end portions first end portion 18 a is supported on the first side wall main body 12 c, while thesecond end portion 18 b is supported on asecond case 56 b of amotor case 56 of themotor 30. Theintermediate axle 18 rotatably supports the secondrotation transmitting member 20. - The second
rotation transmitting member 20 is a member that transmits the rotation of the firstrotation transmitting member 16. The secondrotation transmitting member 20 has asecond gear 20 a that meshes with thefirst gear 16 a, and afirst sprocket 20 b that rotates together with thesecond gear 20 a. The secondrotation transmitting member 20 is a member made of, for example, a synthetic resin or a metal. The secondrotation transmitting member 20 is rotatably supported on theintermediate axle 18 via abearing 40, such as, for example, a needle-shaped roller bearing. Thesecond gear 20 a has anengagement section 20 c engaged with an innerperipheral portion 20 d of thefirst sprocket 20 b. Theengagement section 20 c is formed on a toothed surface that is not engaged with thefirst gear 16 a among the toothed surface of thesecond gear 20 a. On the innerperipheral portion 20 d of thefirst sprocket 20 b, an engagement portion engaged with at least a portion of thesecond gear 20 a is formed. As a result, thesecond gear 20 a and thefirst sprocket 20 b are non-rotatably coupled to each other. Furthermore, retainers are disposed on thesecond gear 20 a for prohibiting an axial movement of thefirst sprocket 20 b in the axial direction of theintermediate axle 18. The retainers are disposed on both sides of thefirst sprocket 20 b in the axial direction of theintermediate axle 18. - The
support axle 22 is arranged to support thegear shifting mechanism 32 and theclutch mechanism 38 with respect to thehousing 12. Thesupport axle 22 has end portions that extend through thesecond holes support axle 22 are fastened to the first andsecond side walls second side walls support axle 22 extends through thegear shifting mechanism 32 and theclutch mechanism 38. Thesupport axle 22 rotatably supports the thirdrotation transmitting member 26. - The third
rotation transmitting member 26 is a member that transmits the rotation of the secondrotation transmitting member 20. The rotation of the secondrotation transmitting member 20 is transmitted by thesecond chain 24 to the thirdrotation transmitting member 26. The thirdrotation transmitting member 26 has asecond sprocket 26 a engaged with thesecond chain 24. Thesecond chain 24 is wound on thefirst sprocket 20 b and thesecond sprocket 26 a. Thesecond sprocket 26 a is operatively coupled to thegear shifting mechanism 32. In particular, thesecond sprocket 26 a is fixedly coupled to aninput part 64 of thegear shifting mechanism 32. Thus, thesecond sprocket 26 a is rotatably supported on thesupport axle 22 via theinput part 64. - As shown in
FIG. 2 , themotor 30 is an inner rotor-type motor. Themotor 30 has themotor case 56, arotor 58 that is rotatably supported on themotor case 56, and astator 60 installed on themotor case 56. In the illustrated embodiment, themotor case 56 has a first case 56 a integrally formed with thehousing 12, and thesecond case 56 b detachably coupled to the first case 56 a. Themotor case 56 further has anaxle supporting recess 56 c that supports thesecond end portion 18 b of theintermediate axle 18 on thesecond case 56 b. - The
rotor 58 is a cylindrical member that is coaxially arranged relative to the crank axle 14. The crank axle 14 extends through therotor 58. Therotor 58 has amagnet unit 58 a with a plurality of magnetic poles arranged on the outer peripheral portion of therotor 58 side by side in the circumferential direction. Therotor 58 of themotor 30 has a crankaxle receiving hole 58 b. The crank axle 14 is rotatably disposed in the crankaxle receiving hole 58 b of therotor 58 of themotor 30. Therotor 58 is rotatably supported on themotor case 56 by a pair ofbearings bearings rotor 58. The bearing 62 a is installed on the first case 56 a, while thebearing 62 b is installed on thesecond case 56 b. - The
stator 60 is arranged opposite to therotor 58 on the outer peripheral side of therotor 58. Thestator 60 has a plurality ofcoils 60 a arranged at a certain interval in the circumferential direction. Thestator 60 is fixedly coupled to the inner peripheral portion of the first case 56 a. - In the illustrated embodiment, the
motor 30 is driven by an inverter (not shown). The inverter is driven by a controller (not shown). The controller controls the inverter based on the pedaling force and the speed of the bicycle. - In the illustrated embodiment, the rotational axes of the
motor 30 and the crank axle 14 are coincident with each other. Thus, it is possible to simplify the internal mechanism of themotor 30. As a result, thedrive unit 10 can be further simplified. However, of course, it will be apparent to those skilled in the art from this disclosure that themotor 30 and the crank axle 14 can be arranged with respect to each other such that the rotational axes the rotational axes of themotor 30 and the crank axle 14 are offset with respect to each other. - The
gear shifting mechanism 32 is arranged on the power transmission passage between the thirdrotation transmitting member 26 and thetorque combining mechanism 36. Thegear shifting mechanism 32 has a shiftingmotor unit 32 a. Thegear shifting mechanism 32 has a gear shiftingmain body 32 b. The shiftingmotor unit 32 a rotates an actuating member of the gear shiftingmain body 32 b to a prescribed phase upon receiving a shift operation from a shifter installed on a handle of the bicycle. The shiftingmotor unit 32 a is a conventionally well-known motor unit, such as a motor unit disclosed in, for example. Japanese Patent No. 3529723. However, of course, it will be apparent to those skilled in the art from this disclosure that the shiftingmotor unit 32 a can be replaced with a conventionally well-known mechanism for shifting the power transmission paths of the gear shiftingmain body 32 b, such as a wire operated actuator operated by receiving a shift operation from a shifter installed on the handle of the bicycle. - The gear shifting
main body 32 b is a transmission unit that allows selection from a plurality of (e.g., 8) gear ratios. The configuration of the gear shiftingmain body 32 b is basically identical to a conventionally well-known transmission unit, such as a transmission unit disclosed in U.S. Pat. No. 6,607,465 or U.S. Patent No. 7,682,283, except for the configurations as described in detail below. - The gear shifting
main body 32 b of thegear shifting mechanism 32 mainly includes thesupport axle 22, theinput part 64, aplanetary gear unit 66, and anoutput part 68. The rotation of the thirdrotation transmitting member 26 is transmitted to theinput part 64, theplanetary gear unit 66 and theoutput part 68. Theinput part 64, theplanetary gear unit 66 and theoutput part 68 are rotatably supported on thesupport axle 22, respectively. Specifically, theinput part 64 is rotatably supported on thesupport axle 22 and operatively coupled to the crank axle 14. Thesecond sprocket 26 a of the thirdrotation transmitting member 26 is fixedly coupled to theinput part 64 such that they can rotate together. Theplanetary gear unit 66 is disposed between theinput part 64 and theoutput part 68. Theplanetary gear unit 66 selectively establishes a plurality of (e.g., 8) gear ratios. Theoutput part 68 is rotatably supported on thesupport axle 22 and operatively coupled to thetorque combining mechanism 36. Theoutput part 68 outputs the rotation after changing the rotational speed by theplanetary gear unit 66 to thetorque combining mechanism 36. - The
gear shifting mechanism 32 is arranged in thedrive unit 10. It is possible to select from a plurality of gear ratios by thegear shifting mechanism 32. Consequently, assisting driving by themotor 30 can be carried out at a high efficiency. Also, even when an internal transmission unit is adopted as thegear shifting mechanism 32, as the force acting on thegear shifting mechanism 32 is small, the transmission operation can be carried out quickly. The configurations of thegear shifting mechanism 32 will be described in detail later. - The
reduction gear unit 34 transmits the rotation of therotor 58 of themotor 30 to a torque transmitting member 70. Thereduction gear unit 34 has one or more gears. In the illustrated embodiment, thereduction gear unit 34 has a firstplanetary gear mechanism 72 and a secondplanetary gear mechanism 74. The firstplanetary gear mechanism 72 has afirst sun gear 72 a connected to therotor 58, a plurality of firstplanetary gears 72 b, afirst carrier 72 c rotatably supporting the firstplanetary gears 72 b, and afirst ring gear 72 d fixedly coupled to thehousing 12. The secondplanetary gear mechanism 74 has asecond sun gear 74 a connected to thefirst carrier 72 c, a plurality of secondplanetary gears 74 b, asecond carrier 74 c rotatably supporting the secondplanetary gears 74 b, and asecond ring gear 74 d fixedly coupled to thehousing 12. The rotational output of thereduction gear unit 34 is transmitted via the torque transmitting member 70 to thetorque combining mechanism 36. The torque transmitting member 70 is integrally formed with thesecond carrier 74 c. The torque transmitting member 70 is rotatably supported by asecond gear member 78 of thetorque combining mechanism 36. The torque transmitting member 70 supports a plurality ofclutch pawls 80 a of a one-way clutch 80. - The
torque combining mechanism 36 transmits the rotating force of themotor 30 and the rotating force of the crank axle 14 to thefront sprocket 28. Thetorque combining mechanism 36 is operatively coupled to themotor 30 and the crank axle 14 to combine the rotational outputs of themotor 30 and the crank axle 14. Thetorque combining mechanism 36 has afirst gear member 76 fixedly coupled to theoutput part 68 of thegear shifting mechanism 32, asecond gear member 78 that meshes with thefirst gear member 76, and the one-way clutch 80. Thetorque combining mechanism 36 is operatively connected to the rotor 58 (e.g., a rotational output portion) of themotor 30 through the one-way clutch 80 to receive the rotational output of themotor 30. - The
second gear member 78 is rotatably supported on thehousing 12 via thesecond bearing 39 b on thehousing 12. Between the inner peripheral portion of thesecond gear member 78 and the outer peripheral surface of the crank axle 14, a bearing 82 in the form of, for example, a ball bearing is installed. Consequently, the crank axle 14 is rotatably supported on thehousing 12 via thesecond gear member 78. - The
second gear member 78 has a firstannular recess 78 a in which the one-way clutch 80 is disposed and a secondannular recess 78 b in which thebearing 39 b is disposed. Thesecond gear member 78 of thetorque combining mechanism 36 has asprocket mounting portion 78 c. - The first
annular recess 78 a is formed in annular shape on the surface of thehousing 12 opposite to thesecond side wall 12 b. The outer peripheral portion on the inner side of the firstannular recess 78 a rotatably supports the torque transmitting member 70. The secondannular recess 78 b is formed in annular shape on the surface opposite to thesecond side wall 12 b. The inner ring of thesecond bearing 39 b is disposed in the secondannular recess 78 b. Thesprocket mounting portion 78 c is configured to be operatively attached to thefront sprocket 28 such that thefront sprocket 28 rotates about the rotational axis X1 (e.g., a second rotational axis of a sprocket) in the forward rotational direction (e.g., a first direction) as the crank axle 14 rotates about the rotational axis X1 in the forward rotational direction. Thesprocket mounting portion 78 c extends in annular shape in the axial direction of the crank axle 14 from the outer peripheral surface on the inner side of the secondannular recess 78 b. In thesecond gear member 78, the secondannular recess 78 b is formed on the radially inner side of the firstannular recess 78 a. Thefront sprocket 28 is fixedly coupled to a connectingsection 78 d on the inner peripheral surface of thesprocket mounting portion 78 c. The connectingsection 78 d can have serrations. Thefront sprocket 28 is pressed into the connectingsection 78 d and is fixed by caulking with a plastic deformation, for example. Thus, thesecond gear member 78 and thefront sprocket 28 rotate together. - In the illustrated embodiment, the one-way clutch 80 only transmits the forward rotation of the
motor 30 that drives the bicycle in the forward direction to thesecond gear member 78. On the other hand, the forward rotation of thesecond gear member 78 relative to themotor 30 is not transmitted to themotor 30. The one-way clutch 80 has aclutch pawl 80 a, aclutch tooth 80 b, and aninner side member 80 c. Theclutch pawl 80 a is accommodated such that theclutch pawl 80 a can pivot along the outer peripheral surface of theinner side member 80 c between a release position and an engagement position. Theclutch pawl 80 a is biased towards the engagement position. Theclutch tooth 80 b is formed on the inner peripheral surface on the outer side of the firstannular recess 78 a. Theinner side member 80 c is formed in annular shape. The torque transmitting member 70 is rotatably supported on the inner peripheral portion of theinner side member 80 c. - The
front sprocket 28 has anannular section 28 b withsprocket teeth 28 a formed on the outer peripheral portion, and acylindrical section 28 c integrally formed on the inner peripheral portion of theannular section 28 b. The outer peripheral surface of thecylindrical section 28 c is pressed into the inner peripheral portion of the secondannular recess 78 b, and the tip portion of thecylindrical section 28 c is fixed by caulking. However, the method for fixing thefront sprocket 28 is not limited to the press-fit. Thefront sprocket 28 can be fixed to thesecond gear member 78 by any other suitable manner, such as screwing, bonding, fusion welding, etc. Thefront sprocket 28 rotates about the rotational axis X1 of the crank axle 14. Thus, the rotational axis of the crank axle 14 (e.g., a first rotational axis) and the rotational axis of the front sprocket 28 (e.g., a second rotational axis) are coincident with each other. However, of course, it will be apparent to those skilled in the art from this disclosure thatfront sprocket 28 and the crank axle 14 can be arranged with respect to each other such that the rotational axes of thefront sprocket 28 and the crank axle 14 are offset with respect to each other. - Referring now to
FIG. 3 , the configuration of thegear shifting mechanism 32 will be further described in detail. As shown inFIG. 3 , theplanetary gear unit 66 of thegear shifting mechanism 32 includes apower transmitting mechanism 112 and a shift/assistmechanism 114. Thepower transmitting mechanism 112 is disposed between theinput part 64 and theoutput part 68 for communicating rotational power from theinput part 64 to theoutput part 68 through a plurality of power transmission paths. The shift/assistmechanism 114 controls the selection of the power transmission paths by receiving the rotational input from the shiftingmotor unit 32 a. - The
input part 64 is rotatably supported on thesupport axle 22 through aball bearing 118 and a bearingcone 120. The bearingcone 120 is maintained in place by anactuator plate 122, aspacer 124, awasher 126 and alock nut 128. - The
output part 68 has aleft cup 130 and aright cup 132. Theleft cup 130 is non-rotatably fitted at the left side of an inner peripheral surface of theoutput part 68, while theright cup 132 is non-rotatably fitted at the right side of the inner peripheral surface of theoutput part 68. Theleft cup 130 rotatably supports theoutput part 68 relative to theinput part 64 throughball bearings 136. Theright cup 132 rotatably supports theoutput part 68 on thesupport axle 22 through aball bearing 140 and acone 142. Thecone 142 is maintained on thesupport axle 22 by astop nut 144. In the illustrated embodiment, theleft cup 130 and theright cup 132 are independently formed as separate members from theoutput part 68. However, theleft cup 130 or theright cup 132 can be integrally formed with theoutput part 68 as a one-piece, unitary member. - The
power transmitting mechanism 112 includes afirst sun gear 148, a separatesecond sun gear 150, a separate third sun gear 152, and a separate fourth sun gear 154. Thefirst sun gear 148 is non-rotatably supported to thesupport axle 22. Thefirst sun gear 148 includes aclutch cam portion 156, and a plurality of first sun gear teeth 158 (e.g., 48 T) formed on an outer peripheral surface thereof, and an inner peripheral second sungear contact surface 160. Thesecond sun gear 150 is rotatably supported around thesupport axle 22 adjacent to thefirst sun gear 148. Thesecond sun gear 150 includes an outer peripheral first sungear contact surface 162 for slidably contacting the second sungear contact surface 160 on thefirst sun gear 148, a plurality of second sun gear ratchet teeth 168 (e.g., 12 T) formed on an inner peripheral surface thereof for engaging a secondsun gear pawl 170, an inner peripheral third sun gear contact surface 166, and a plurality of second sun gear teeth 164 (e.g., 48 T) formed on an outer peripheral surface thereof. Thesecond sun gear 150 further has an inner peripheral guide ring contact surface for slidably contacting an outer peripheral surface of a sungear guide ring 176. The third sun gear 152 is rotatably supported around thesupport axle 22 adjacent to thesecond sun gear 150. The third sun gear 152 includes an inner peripheral first guide ring contact surface for slidably contacting the outer peripheral surface of the sungear guide ring 176. The third sun gear 152 includes a plurality of third sun gear ratchet teeth 180 (e.g., 12 T) formed on an inner peripheral surface thereof for engaging a thirdsun gear pawl 182, an outer peripheral second sungear contact surface 184 for slidably contacting the third sun gear contact surface 166 of thesecond sun gear 150, and a plurality of third sun gear teeth 186 (e.g., 42 T) formed on an outer peripheral surface thereof. The fourth sun gear 154 includes a plurality of fourth sun gear teeth 188 (e.g., 36 T) formed on an outer peripheral surface thereof, a plurality of fourth sun gear ratchet teeth 190 (e.g., 12 T) formed on an inner peripheral surface thereof for engaging a fourthsun gear pawl 192. The fourth sun gear 154 includes an inner peripheral guide ring contact surface for slidably contacting an outer peripheral surface of a guide ring 198. - The
pawls support axle 22, and controlled by a shift control sleeve (not shown) for selectively switching between a free state and a lock state of the second, third and fourth sun gears 150, 152 and 154 in a conventional manner. Each of the second, third and fourth sun gears 150, 152 and 154 rotates about thesupport axle 22 in the free state, while each of the second, third and fourth sun gears 150, 152 and 154 is prevented from rotating about thesupport axle 22 in the lock state. With this switching of the states, one of the power transmission paths from theinput part 64 to theoutput part 68 are selected. The configurations and the operations of the shift control sleeve are conventionally well known in U.S. Pat. Nos. 6,607,465 and 7,682,283, for example. Thus, the detailed configurations will be omitted for the sake of brevity. - As shown in
FIG. 3 , thepower transmitting mechanism 112 further includes aplanetary gear carrier 200, afirst ring gear 202, a second ring gear 204, a plurality of (e.g., three) first planet gears 206, and a plurality of (e.g., three) second planetary gears 208. - The
planetary gear carrier 200 is rotatably mounted around thesupport axle 22. Theplanetary gear carrier 200 rotatably supports the firstplanetary gears 206 about a plurality of (e.g., three) first pinion pins 210, and rotatably supports the secondplanetary gears 208 about a plurality of (e.g., three) second pinion pins 212. The first and second pinion pins 210 and 212 are fixedly coupled to theplanetary gear carrier 200. Specifically, the first pinion pins 210 are equidistantly arranged on theplanetary gear carrier 200 in the circumferential direction about thesupport axle 22, while the second pinion pins 212 are equidistantly arranged on theplanetary gear carrier 200 in the circumferential direction about thesupport axle 22. Each of the first pinion pins 210 is concentrically arranged with respect to respective one of the second pinion pins 212. In the illustrated embodiment, the first and second pinion pins 210 and 212 are independently formed as separate members. However, the first and second pinion pins 210 and 212 that are concentrically disposed can be integrally formed as a one-piece, unitary member. Theplanetary gear carrier 200 is made of a light alloy metal such as an aluminum alloy, steel, or any other suitably material. Furthermore, theplanetary gear carrier 200 can be formed by combining a plurality of separate parts. - The
first pinion pins 210 rotatably support the firstplanetary gears 206, respectively. Each of the firstplanetary gears 206 has a small diameter gear portion 220 (e.g., 14 T) engaging with the first sun gear teeth 158 of thefirst sun gear 148, and a large diameter gear portion 222 (e.g., 22 T) engaging with a first inner peripheral gear portion 224 (e.g., 84 T) of thefirst ring gear 202. Similarly, thesecond pinion pins 212 rotatably support the secondplanetary gears 208, respectively. Each of the secondplanetary gears 208 includes a large diameter gear portion 226 (e.g., 29 T) engaging with the fourthsun gear teeth 188 of the fourth sun gear 154, an intermediate diameter gear portion 228 (e.g., 18 T) engaging with the thirdsun gear teeth 186 of the third sun gear 152, and a small diameter gear portion 230 (e.g., 14 T) engaging with the secondsun gear teeth 164 ofsecond sun gear 150 and an inner peripheral gear portion 232 (e.g., 78 T) of the second ring gear 204. - The
planetary gear carrier 200 further has a plurality (e.g., 12) ofsplines 238 on an inner peripheral surface of a left end portion of theplanetary gear carrier 200. The clutchengaging splines 238 of theplanetary gear carrier 200 are selectively engaged with a plurality ofsplines 240 circumferentially disposed on aclutch ring 242. In particular, theclutch ring 242 is slidable along a center axis of thesupport axle 22 between an engaging position and a disengaging position in response to the rotational input from the shiftingmotor unit 32 a. Theclutch ring 242 is non-rotatably coupled to splines on an inner peripheral surface of theinput part 64. Thus, theclutch ring 242 couples theinput part 64 with theplanetary gear carrier 200 when theclutch ring 242 is located on the engaging position such that theinput part 64 and theplanetary gear carrier 200 rotate together. On the other hand, theinput part 64 is disengaged from theplanetary gear carrier 200 when theclutch ring 242 is located on the disengaging position. - The
first ring gear 202 further includes a second inner peripheral gear portion 244 (e.g., 36 T) for engaging a plurality of circumferentially disposedpawls 246 that are pivotally mounted to an outer peripheral surface of theinput part 64. Thepawls 246 are biased radially outwardly by apawl spring 248 and thus function as a clutch between theinput part 64 and thefirst ring gear 202. A plurality ofpawls 249 also are circumferentially disposed on the outer peripheral surface of theinput part 64 for driving thefirst ring gear 202 in response to the rearward rotation of the crank axle 14 in a conventionally well-known manner. - The second ring gear 204 is coupled to the
output part 68 via a one-way clutch 250 in the form of a roller clutch having a plurality of (e.g., 18) rollers and cam surfaces. The one-way clutch 250 is configured such that the one-way clutch 250 only transmits the forward rotation of the crank axle 14 to theoutput part 68. - In the illustrated embodiment, the
power transmitting mechanism 112 of theplanetary gear unit 66 further includes aslide spring 254 disposed between the first and second sun gears 148 and 150. In other words, thepower transmitting mechanism 112 of theplanetary gear unit 66 includes the first and second sun gears 148 and 150 that are operatively connected by theslide spring 254. As shown inFIGS. 5 , 8 and 9, theslide spring 254 has aleg portion 254 a and aring portion 254 b. As shown inFIG. 3 , theleg portion 254 a is disposed in a receivinghole 256 of thefirst sun gear 148. Thering portion 254 b extends from theleg portion 254 a and is disposed in an innercircumferential groove 258 of thesecond sun gear 150. Specifically, thering portion 254 b has a larger diameter than that of the innercircumferential groove 258 of thesecond sun gear 150 when theslide spring 254 is in an unloaded state as shown inFIGS. 8 and 9 . Thus, thering portion 254 b of theslide spring 254 is in a loaded state while thering portion 254 b is disposed in the innercircumferential groove 258 of thesecond sun gear 150 as shown inFIGS. 3 . In particular, theleg portion 254 a of theslide spring 254 is disposed in the receivinghole 256 of thefirst sun gear 148 such that theslide spring 254 is non-rotatably coupled to thefirst sun gear 148. On the other hand, thering portion 254 b of theslide spring 254 is slidably disposed in the innercircumferential groove 258 of thesecond sun gear 150 while theslide spring 254 is in the loaded state. Thus, the angular position of thesecond sun gear 150 about thesupport axle 22 with respect to thefirst sun gear 148 is maintained by theslide spring 254 while the rotational force applied to thesecond sun gear 150 is smaller than the retaining or friction force between thering portion 254 b of theslide spring 254 and the innercircumferential groove 258 of thesecond sun gear 150. On the other hand, thesecond sun gear 150 rotates with respect to thefirst sun gear 148 when the rotational force applied to thesecond sun gear 150 becomes larger than the retaining or friction force between thering portion 254 b of theslide spring 254 and thesecond sun gear 150. - Referring now to
FIGS. 2 to 4 , the configuration of theclutch mechanism 38 will be described in detail. Theclutch mechanism 38 is operatively disposed between the crank axle 14 and thefront sprocket 28. Theclutch mechanism 38 is configured to rotate thefront sprocket 28 about the rotational axis X1 in the rearward rotational direction (e.g., a second direction) as the crank axle 14 rotates about the rotational axis X1 in the rearward rotational direction. The rearward rotational direction is opposite the forward rotational direction. Theclutch mechanism 38 permits a relative rotation between the crank axle 14 and thefront sprocket 28 in the forward rotational direction (e.g., the first direction). Theclutch mechanism 38 is supported to thesupport axle 22 of thegear shifting mechanism 32 such that theclutch mechanism 38 is operatively disposed between theplanetary gear carrier 200 of theplanetary gear unit 66 and theoutput part 68 of thegear shifting mechanism 32. Theclutch mechanism 38 includes a toothed part 260 (e.g., an internally toothed part), apawl support 262, a plurality ofengagement pawls 264, and a plurality of biasingmembers 266. Theclutch mechanism 38 includes acontrol part 268. - The
toothed part 260 is disposed on an inner peripheral surface of theright cup 132 of theoutput part 68 of thegear shifting mechanism 32. Thetoothed part 260 has a plurality ofengagement teeth 260 a formed on the inner peripheral surface of theright cup 132. Theengagement teeth 260 a selectively engage with theengagement pawls 264 for transmitting the rearward rotation of the crank axle 14 to theoutput part 68. - The
pawl support 262 is movably attached to theplanetary gear carrier 200 of theplanetary gear unit 66. Specifically, thepawl support 262 is movably attached about anaxially extending portion 270 of theplanetary gear carrier 200 that has alarge diameter section 270 a and asmall diameter section 270 b. Thepawl support 262 is integrally formed as a one-piece, unitary member, and is made of metallic material, or any other suitable material. Thepawl support 262 has first and secondannular sections annular section 272 has a plurality of (e.g., four)pawl receiving openings 272 a that are circumferentially arranged on an outer peripheral surface of the firstannular section 272. The secondannular section 274 has a plurality of clutchpawl mounting sections 274 a that are circumferentially arranged on an outer peripheral surface of the secondannular section 274. - The second
annular section 274 of thepawl support 262 has a plurality ofrecesses 278 disposed in the circumferential direction of thepawl support 262. In particular, therecesses 278 are circumferentially arranged on an inner peripheral surface of the secondannular section 274. Theplanetary gear carrier 200 of theplanetary gear unit 66 has a plurality ofprojections 280. In particular, theprojections 280 are circumferentially arranged on an outer peripheral surface of thelarge diameter section 270 a of theaxially extending portion 270 of theplanetary gear carrier 200. Theprojections 280 are located in therecesses 278, respectively. As shown inFIGS. 6 and 7 , therecesses 278 and theprojections 280 are arranged relative to each other with circumferential spacings therebetween, respectively, to provide a limited range of relative rotation between thepawl support 262 and theplanetary gear carrier 200. In the illustrated embodiment, as shown inFIG. 6 , theprojections 280 have first contact surfaces 280 a (e.g., contact surfaces), respectively, that circumferentially contact with firstinside surfaces 278 a (e.g., inside surfaces) of therecesses 278, respectively, as the crank axle 14 rotates in the forward rotational direction such that the forward rotation of the crank axle 14 in the forward rotational direction is transmitted from theplanetary gear carrier 200 of theplanetary gear unit 66 to theoutput part 68 of thegear shifting mechanism 32 via thepawl support 262. Furthermore, as shown inFIG. 7 , theprojections 280 have second contact surfaces 280 b, respectively, that circumferentially contact with secondinside surfaces 278 b of therecesses 278, respectively, as the crank axle 14 rotates in the rearward rotational direction such that the rearward rotation of the crank axle 14 in the forward rotational direction is transmitted from theplanetary gear carrier 200 of theplanetary gear unit 66 to theoutput part 68 of thegear shifting mechanism 32 via thepawl support 262. The first and second contact surfaces 280 a and 280 b of each of theprojections 280 face in the opposite circumferential directions, while the first and second inside surfaces 278 a and 278 b of each of therecesses 278 face in the opposite circumferential directions. - In the illustrated embodiment, the
pawl support 262 has therecesses 278, while theplanetary gear carrier 200 has theprojections 280. However, alternatively, thepawl support 262 can have a plurality of projections disposed in the circumferential directions of thepawl support 262, while theplanetary gear carrier 200 of theplanetary gear unit 66 can have a plurality of recesses located in the recesses. In this case, the recesses and the projections can be arranged relative to each other with circumferential spacings therebetween, respectively, to provide a limited range of relative rotation between thepawl support 262 and theplanetary gear carrier 200. - As shown in
FIGS. 3 , 4, 6 and 7, theengagement pawls 264 are movably mounted to thepawl support 262 between a release position and an engagement position. Each of theengagement pawls 264 has anengagement end 264 a and acontrol end 264 b. The engagement ends 264 a of theengagement pawls 264 are engaged with theengagement teeth 260 a of theright cup 132 when theengagement pawls 264 are located at the engagement position, while the engagement ends 264 a of theengagement pawls 264 are disengaged from theengagement teeth 260 a of theright cup 132 when theengagement pawls 264 are located at the release position. The engagement pawls 264 are pivotally arranged in thepawl receiving openings 272 a of the firstannular section 272 of thepawl support 262, respectively. More specifically, theengagement pawls 264 are pivotally coupled to a plurality of pivot pins 282, respectively. The pivot pins 282 are fixedly coupled to the firstannular section 272 of thepawl support 262 in thepawl receiving openings 272 a, respectively. - The biasing
members 266 bias theengagement pawls 264 towards the engagement position. The biasingmembers 266 basically includes pawl springs operatively disposed between the engagement pawls 264 and thepawl support 262. - The
control part 268 is disposed on an outer peripheral surface of theplanetary gear carrier 200 of theplanetary gear unit 66. Thecontrol part 268 selectively causes theengagement pawls 264 to engage with thetoothed part 260 as the crank axle 14 rotates in the rearward rotational direction such that theclutch mechanism 38 transmits the rearward rotation of the crank axle 14 to theoutput part 68 of thegear shifting mechanism 32. Specifically, as shown inFIGS. 6 and 7 , thecontrol part 268 has a plurality ofcontrol projections 284 circumferentially arranged on an outer peripheral surface of thesmall diameter section 270 b of theaxially extending portion 270 of theplanetary gear carrier 200. In particular, as shown inFIG. 6 , thecontrol projections 284 are engaged with the control ends 264 b of theengagement pawls 264 while theplanetary gear carrier 200 rotates in response to the forward rotation of the crank axle 14. This moves theengagement pawls 264 towards the release position such that the rotation of theplanetary gear carrier 200 is prevented from being transmitted to theright cup 132 of theoutput part 68 via theengagement pawls 264. On the other hand, as shown inFIG. 7 , thecontrol projections 284 are disengaged with the control ends 264 b of theengagement pawls 264 while theplanetary gear carrier 200 rotates in response to the rearward rotation of the crank axle 14. This moves theengagement pawls 264 back to the engagement position due to the biasing force of the biasingmembers 266 such that the rotation of theplanetary gear carrier 200 is transmitted to theright cup 132 of theoutput part 68 via theengagement pawls 264. More specifically, as shown inFIG. 7 , this rotation of theplanetary gear carrier 200 is transmitted to thepawl support 262 via the connections between theprojections 280 of theplanetary gear carrier 200 and therecesses 278 of thepawl support 262, and then the rotation of thepawl support 262 is transmitted to theright cup 132 of theoutput part 68 via theengagement pawls 264. - The
clutch mechanism 38 further includes a retainingmember 286 operatively disposed between thesupport axle 22 and thepawl support 262. The retainingmember 286 maintains relative angular position between thepawl support 262 and thesupport axle 22 before theengagement pawls 264 engage with theright cup 132 of theoutput part 68. As shown inFIGS. 4 , 10 and 11, the retainingmember 286 of theclutch mechanism 38 further includes aslide spring 288 having aleg portion 288 a and aring portion 288 b. Theleg portion 288 a is non-rotatably coupled to thecone 142 that is fastened to thesupport axle 22 of thegear shifting mechanism 32. Thering portion 288 b extends from theleg portion 288 a and is disposed in an outercircumferential groove 262 a of thepawl support 262 of theclutch mechanism 38. Specifically, thering portion 288 b has a smaller diameter than that of the outercircumferential groove 262 a of thepawl support 262 when theslide spring 288 is in an unloaded state, as shown inFIG. 11 . Thus, thering portion 288 b of theslide spring 288 is in a loaded state, as shown inFIG. 10 , while thering portion 288 b is disposed in the outercircumferential groove 262 a of thepawl support 262. In particular, theleg portion 288 a of theslide spring 288 is disposed in a receivinghole 142 a of thecone 142 such that theslide spring 288 is non-rotatably coupled to thesupport axle 22. On the other hand, thering portion 288 b of theslide spring 288 is slidably disposed in the outercircumferential groove 262 a of thepawl support 262 while theslide spring 288 is in the loaded state. Thus, the angular position of thepawl support 262 about thesupport axle 22 is maintained by theslide spring 288 while the rotational force applied to thepawl support 262 is smaller than the retaining or friction force between thering portion 288 b of theslide spring 288 and the outercircumferential groove 262 a of thepawl support 262. On the other hand, thepawl support 262 rotates with respect to thesupport axle 22 when the rotational force applied to thepawl support 262 becomes larger than the retaining or friction force between thering portion 288 b of theslide spring 288 and the outercircumferential groove 262 a of thepawl support 262. - The
clutch mechanism 38 further includes a one-way clutch 290. The one-way clutch 290 is operatively disposed between thepawl support 262 and theright cup 132 of theoutput part 68 for transmitting the forward rotation of the crank axle 14 to theoutput part 68. Specifically, the one-way clutch 290 has a plurality ofclutch pawls 292 pivotally supported on the clutchpawl mounting sections 274 a of thepawl support 262. Theclutch pawls 292 are biased radially outwardly by a plurality of pawl springs 294 for engaging inner peripheralclutch teeth 296 formed on the inter peripheral surface of the left side of theright cup 132. Theclutch pawls 292 transmit the forward rotation of the crank axle 14 to theright cup 132 and hence to theoutput part 68. In particular, as shown inFIG. 6 , thecontrol projections 284 are engaged with the control ends 264 b of theengagement pawls 264 while theplanetary gear carrier 200 rotates in response to the forward rotation of the crank axle 14. This rotation of theplanetary gear carrier 200 is prevented from being transmitted to theright cup 132 of theoutput part 68 via theengagement pawls 264. However, as shown inFIG. 6 , this rotation of theplanetary gear carrier 200 is transmitted to thepawl support 262 via the connections between theprojections 280 of theplanetary gear carrier 200 and therecesses 278 of thepawl support 262, and then the rotation of thepawl support 262 is transmitted to theright cup 132 of theoutput part 68 via the one-way clutch 290. - In the illustrated embodiment, the
toothed part 260 is disposed on theoutput part 68 of thegear shifting mechanism 32, while thepawl support 262 is movably attached to theplanetary gear carrier 200 of theplanetary gear unit 66. However, alternatively, thetoothed part 260 can be disposed on the planetary gear carrier of theplanetary gear unit 66, while thepawl support 262 is movably attached to theoutput part 68 of thegear shifting mechanism 32. - With this
drive unit 10, as shown inFIG. 2 , the torque generated by the pedaling force in the forward rotational direction is transmitted in the following transmission passage: the crankarms 101→the crank axle 14→the firstrotation transmitting member 16→the secondrotation transmitting member 20→the thirdrotation transmitting member 26→the gear shiftingmain body 32 b→thefirst gear member 76→thesecond gear member 78. On the other hand, the output torque of themotor 30 is transmitted in the following path: thereduction gear unit 34→the torque transmitting member 70→the one-way clutch 80→thesecond gear member 78. Thesecond gear member 78 combines these two torques to transmit them to thefront sprocket 28. Thus, the forward rotation of thecrank arms 101 is transmitted to thefront sprocket 28 after being assisted by themotor 30. In the gear shiftingmain body 32 b, theplanetary gear unit 66 transmits the forward rotation of the crank axle 14 through a plurality of power transmission paths. This shifting operation for selecting one of the power transmission paths is conventionally well known in U.S. Pat. Nos. 6,607,465 and 7,682,283, for example. Thus, the detailed configurations will be omitted for the sake of brevity. - On the other hand, with this
drive unit 10, the rearward rotation of thecrank arms 101 is also transmitted to thefront sprocket 28 to rotate thefront sprocket 28 in the rearward rotational direction. Specifically, the torque generated by the pedaling force in the rearward rotational direction is transmitted in the following transmission passage: the crankarms 101→the crank axle 14→the firstrotation transmitting member 16→the secondrotation transmitting member 20→the thirdrotation transmitting member 26→the gear shiftingmain body 32 b→thefirst gear member 76→thesecond gear member 78→thefront sprocket 28. Specifically, in the gear shiftingmain body 32 b, when the rearward rotation of thecrank arms 101 is transmitted to theinput part 64 of the gear shiftingmain body 32 b, theclutch ring 242 is disengaged from theplanetary gear carrier 200 no matter which of the power transmission paths is selected. Then, the rotation of theinput part 64 is transmitted to theoutput part 68 through the following transmission path: theinput part 64→thepawls 249→thefirst ring gear 202→theplanetary gear carrier 200→theengagement pawls 264→theright cup 132→theoutput part 68. Thus, the rearward rotation of thecrank arms 101 is transmitted to thefront sprocket 28 to rotate thefront sprocket 28 in the rearward rotational direction, thereby operating thecoaster brake 104 a of therear hub 104. - With this
drive unit 10, the gear shiftingmain body 32 b includes the retainingmember 286 that maintains the relative angular position between thesupport axle 22 and thepawl support 262. As shown inFIG. 6 , theplanetary gear carrier 200 and thepawl support 262 rotates together in the clockwise direction while maintaining theengagement pawls 264 at the release position. In response to the rearward rotation of theclank arms 101 for operating thecoaster brake 104 a, theplanetary gear carrier 200 starts to rotate in the counter-clockwise direction inFIG. 6 . If thepawl support 262 starts to rotate together with theplanetary gear carrier 200 in the counter-clockwise direction inFIG. 6 in response to the rearward rotation of theclank arms 101, theengagement pawls 264 do not engage with thetoothed part 260 as shown inFIG. 6 . However, with thisdrive unit 10, the retainingmember 286 maintains the relative angular position between thesupport axle 22 and thepawl support 262 until the rotational force applied to thepawl support 262 becomes larger than the retaining or friction force between theslide spring 288 of the retainingmember 286 and thepawl support 262. Thus, the retainingmember 286 allows theplanetary gear carrier 200 to relatively rotate with respect to thepawl support 262 in response to the rearward rotation of thecrank arms 101, and prevents thepawl support 262 from rotating together with theplanetary gear carrier 200 in the counter-clockwise direction until the positional relationship between theplanetary gear carrier 200 and thepawl support 262 transitions from the positional relationship shown inFIG. 6 to the positional relationship shown inFIG. 7 . Thus, with thisdrive unit 10, theengagement pawls 264 of theclutch mechanism 38 can be properly operated in response to the rearward rotation of thecrank arms 101. - With this
drive unit 10, the gear shiftingmain body 32 b includes theslide spring 254 that maintains the relative angular position between the first and second sun gears 148 and 150. While thecrank arms 101 rotate in the forward rotational direction, the one-way clutch 250 engages the second ring gear 204 and theoutput part 68. Furthermore, if the rotation of thecrank arms 101 is stopped, the one-way clutch 250 still engages the second ring gear 204 and theoutput part 68. In this case, if theengagement pawls 264 becomes engaged with thetoothed part 260 of theright cup 132 of theoutput part 68 before the one-way clutch 250 becomes disengaged in response to the rearward rotation of thecrank arms 101 for operating thecoaster brake 104 a, then thegear shifting mechanism 32 may be locked up since both of theclutch mechanism 38 and the one-way clutch 250 are engaged with theoutput part 68. However, with thisdrive unit 10, theslide spring 254 maintains the relative angular position between the first and second sun gears 148 and 150 until the rotational force applied to thesecond sun gear 150 becomes larger than the retaining or friction force between theslide spring 254 and thesecond sun gear 150. Thus, in response to the rearward rotation of thecrank arms 101, the secondplanetary gears 208 is first rotated while thesecond sun gear 150 meshed with the secondplanetary gears 208 is stationary with respect to thefirst sun gear 148, which also rotates the second ring gear 204 for disengaging the one-way clutch 250. After the one-way clutch 250 is disengaged, theengagement pawls 264 become engaged with thetoothed part 260 of theright cup 132 of theoutput part 68. Therefore, theslide spring 254 prevents both of theclutch mechanism 38 and the one-way clutch 250 from being engaged with theoutput part 68 in response to the rearward rotation of thecrank arms 101, which prevents thegear shifting mechanism 32 from being locked up. Thus, thecoaster brake 104 a can be properly operated in response to the rearward rotation of thecrank arms 101. - In the illustrated embodiment, the first
rotation transmitting member 16, the secondrotation transmitting member 20, and the thirdrotation transmitting member 26 can be made of any appropriate parts selected from the group of gears, sprockets, and pulleys. - In the illustrated embodiment, the bearings are ball bearings or needle-shaped roller bearings. However, it will be apparent to those skilled in the art from this disclosure that any types of bearings that allow the members to be rotatably installed can be adopted. For example, in addition to the ball bearings and the needle-shaped roller bearings, other types of roller bearings, as well as bushes or other sliding-type bearings, can also be applied to the illustrated embodiment.
- Referring now to
FIG. 12 , adrive unit 310 in accordance with a second embodiment will now be explained. - In view of the similarity between the first and second embodiments, the parts of the second embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment. In any event, the descriptions of the parts of the second embodiment that are substantially identical to the parts of the first embodiment may be omitted for the sake of brevity. However, it will be apparent to those skilled in the art from this disclosure that the descriptions and illustrations of the first embodiment also apply to this second embodiment, except as discussed and/or illustrated herein.
- Basically, the
drive unit 310 is arranged in a vicinity of the crank arms 101 (seeFIG. 1 ). In the illustrated embodiment, as shown inFIG. 12 , thedrive unit 310 has ahousing 312, acrank axle 314, a firstrotation transmitting member 316, anintermediate axle 318, a secondrotation transmitting member 320, asupport axle 322, asecond chain 324, a thirdrotation transmitting member 326 and a front sprocket 328 (e.g., a sprocket). In the illustrated embodiment, thecrank axle 314, theintermediate axle 318 and thesupport axle 322 are arranged to extend parallel to each other at spaced locations. As shown inFIG. 12 , thedrive unit 310 has amotor 330, agear shifting mechanism 332, areduction gear unit 334, atorque combining mechanism 336, and aclutch mechanism 338. Thus, thebicycle drive unit 310 includes themotor 330, thecrank axle 314, thetorque combining mechanism 336, and theclutch mechanism 338. - In the illustrated embodiment, the
housing 312, thecrank axle 314, the firstrotation transmitting member 316, theintermediate axle 318, the secondrotation transmitting member 320, thesupport axle 322, thesecond chain 324, the thirdrotation transmitting member 326, themotor 330, thereduction gear unit 334, thetorque combining mechanism 336 are basically identical to thehousing 12, the crank axle 14, the firstrotation transmitting member 16, theintermediate axle 18, the secondrotation transmitting member 20, thesupport axle 22, thesecond chain 24, the thirdrotation transmitting member 26, themotor 30, thereduction gear unit 34, thetorque combining mechanism 36 in accordance with the first embodiment, except for minor changes. Thus, the detailed descriptions of these components will be omitted for the sake of brevity. - In the illustrated embodiment, the
crank axle 314 is rotatable about a rotational axis X1 (e.g., a first rotational axis). Themotor 330 includes a crankaxle receiving hole 330 a. Thecrank axle 314 is rotatably disposed in the crankaxle receiving hole 330 a of themotor 330. - The
gear shifting mechanism 332 is arranged on the power transmission passage between the thirdrotation transmitting member 326 and thetorque combining mechanism 336. Thegear shifting mechanism 332 has a shiftingmotor unit 332 a. Thegear shifting mechanism 332 has a gear shiftingmain body 332 b. The shiftingmotor unit 332 a rotates an actuating member of the gear shiftingmain body 332 b to a prescribed phase upon receiving a shift operation from a shifter installed on a handle of the bicycle. The shiftingmotor unit 332 a is identical to the shiftingmotor unit 32 a in accordance with the first embodiment. Thus, the detailed descriptions will be omitted for the sake of brevity. - The gear shifting
main body 332 b is a transmission unit that allows selection from a plurality of (e.g., 8) gear ratios. The configuration of the gear shiftingmain body 332 b is basically identical to a conventionally well-known transmission unit, such as a transmission unit disclosed in Japanese Utility Model Registration No. 3146138. Thus, the detailed descriptions will be omitted for the sake of brevity. In the illustrated embodiment, the gear shiftingmain body 332 b of thegear shifting mechanism 332 includes thesupport axle 322, aninput part 344, aplanetary gear unit 346, and anoutput part 348. The rotation of the thirdrotation transmitting member 326 is transmitted to theinput part 344, theplanetary gear unit 346 and theoutput part 348. Theinput part 344, theplanetary gear unit 346 and theoutput part 348 are rotatably supported on thesupport axle 322, respectively. Specifically, theinput part 344 is rotatably supported on thesupport axle 322 and operatively coupled to the crankaxle 314. The thirdrotation transmitting member 326 is fixedly coupled to theinput part 344 such that they can rotate together. Theplanetary gear unit 346 is disposed between theinput part 344 and theoutput part 348. Theplanetary gear unit 346 selectively establishes a plurality of (e.g., 8) gear ratios. Theoutput part 348 is rotatably supported on thesupport axle 322 and operatively coupled to thetorque combining mechanism 336. Theoutput part 348 outputs the rotation after changing the rotational speed by theplanetary gear unit 346 to thetorque combining mechanism 336. - The
reduction gear unit 334 is also identical to thereduction gear unit 34, except for first and second ring gears 372 d and 374 d are coupled to an inner peripheral surface of an axially extending portion of amotor case 356. Thus, the detailed configurations will be omitted for the sake of brevity. - The
torque combining mechanism 336 is operatively coupled to themotor 330 and thecrank axle 314 to combine rotational outputs of themotor 330 and thecrank axle 314. Thetorque combining mechanism 336 has afirst gear member 376 fixedly coupled to theoutput part 348 of thegear shifting mechanism 332, asecond gear member 378 that meshes with thefirst gear member 376, and a one-way clutch 380. Thetorque combining mechanism 336 is operatively connected to a rotor 358 (e.g., a rotational output portion) of themotor 330 through the one-way clutch 380 to receive the rotational output of themotor 330. - The
second gear member 378 is basically identical to thesecond gear member 78, except that thefront sprocket 328 is movably attached to thesecond gear member 378. Thus, the detailed description will be omitted for the sake of brevity. As shown inFIG. 12 , thesecond gear member 378 of thetorque combining mechanism 336 has asprocket mounting portion 379 that is configured to be operatively attached to the front sprocket 328 (e.g., a sprocket) such that thefront sprocket 328 rotates about the rotational axis X1 (e.g., a second rotational axis of a sprocket) in the forward rotational direction (e.g., a first direction) as thecrank axle 314 rotates about the rotational axis X1 in the forward rotational direction. - The
clutch mechanism 338 is operatively disposed between thecrank axle 314 and thefront sprocket 328. Theclutch mechanism 338 is configured to rotate thefront sprocket 328 about the rotational axis X1 (e.g., a second rotational axis) in the rearward rotational direction (e.g., a second direction) as thecrank axle 314 rotates about the rotational axis X1 in the rearward rotational direction. The rearward rotational direction is opposite the forward rotational direction. Theclutch mechanism 338 permits a relative rotation between thecrank axle 314 and thefront sprocket 328 in the forward rotational direction (e.g., the first direction). In the illustrated embodiment, theclutch mechanism 338 is supported on thecrank axle 314 between thecrank axle 314 and thefront sprocket 328. However, alternatively, theclutch mechanism 338 can also be supported on thefront sprocket 328 or thetorque combining mechanism 336 between thecrank axle 314 and thefront sprocket 328. Theclutch mechanism 338 includes a toothed part 360 (e.g., an internally toothed part), apawl support 362, a plurality ofengagement pawls 364, a plurality of biasingmembers 366. Theclutch mechanism 338 also includes acontrol part 368. - The
toothed part 360 is disposed on thefront sprocket 328. In particular, thetoothed part 360 is disposed on an innerperipheral surface 385 a of thefront sprocket 328. Thetoothed part 360 has a plurality ofengagement teeth 360 a formed on the innerperipheral surface 385 a of thefront sprocket 328. Theengagement teeth 360 a selectively engage with theengagement pawls 364 for transmitting the rearward rotation of thecrank axle 314 to thefront sprocket 328. - The
pawl support 362 is fixedly coupled to the crankaxle 314. Thepawl support 362 pivotally supports theengagement pawls 364 on an outer peripheral surface of thepawl support 362 in a conventional manner. In the illustrated embodiment, thetoothed part 360 is disposed on thefront sprocket 328, while thepawl support 362 is fixedly coupled to the crankaxle 314. However, alternatively, thetoothed part 360 can be disposed on thecrank axle 314, while thepawl support 362 can be fixedly coupled to thefront sprocket 328. In particular, thetoothed part 360 can be disposed on an outer peripheral surface of thecrank axle 314, while thepawl support 362 can be fixedly coupled to the innerperipheral surface 385 a thefront sprocket 328. Furthermore, thetoothed part 360 can be disposed on one of thesprocket mounting portion 379 and thecrank axle 314, while thepawl support 362 can be fixedly coupled to the other of thesprocket mounting portion 379 and thecrank axle 314. In particular, thetoothed part 360 can be disposed on one of the innerperipheral surface 385 a of thesprocket mounting portion 379 and the outer peripheral surface of thecrank axle 314, while thepawl support 362 can be fixedly coupled to the other of the innerperipheral surface 385 a of thesprocket mounting portion 379 and the outer peripheral surface of thecrank axle 314. - As shown in
FIGS. 13A to 13M , theengagement pawls 364 are movably mounted to thepawl support 362 between a release position and an engagement position. Each of theengagement pawls 364 has anengagement end 364 a and apivot end 364 b. The engagement ends 364 a of theengagement pawls 364 are engaged with theengagement teeth 360 a of thefront sprocket 328 when theengagement pawls 364 are located at the engagement position, while the engagement ends 364 a of theengagement pawls 364 are disengaged from theengagement teeth 360 a of thefront sprocket 328 when theengagement pawls 364 are moved towards the release position. The engagement pawls 364 are pivotally coupled to thepawl support 362 such that theengagement pawls 364 pivot about a pivot axis on thepivot end 364 b in a conventional manner. - The biasing
members 366 bias theengagement pawls 364 towards the engagement position, respectively. The biasingmembers 366 basically includes pawl springs operatively disposed between the engagement pawls 364 and thepawl support 362. - The
control part 368 is disposed on an innerperipheral surface 379 a of the sprocket mounting portion 379 (e.g., an output member) of thetorque combining mechanism 336. Thecontrol part 368 selectively causes theengagement pawls 364 to engage with thetoothed part 360 as thecrank axle 314 rotates in the rearward rotational direction such that theclutch mechanism 338 transmits a rotation of thecrank axle 314 to thefront sprocket 328. On the other hand, thecontrol part 368 is aligned with thetoothed part 360 as thecrank axle 314 rotates in the forward rotational direction such that theengagement pawls 364 slide over thecontrol part 368 and thetoothed part 360 as thecrank axle 314 rotates in the forward rotational direction. More specifically, as shown inFIGS. 13A to 13M , thecontrol part 368 has a plurality ofbumps 391 circumferentially arranged on the innerperipheral surface 379 a of thesprocket mounting portion 379. Each of thebumps 391 has aslope surface 391 a. Theslope surface 391 a is flatter than anengagement surface 360 b of each of theengagement teeth 360 a that engages with theengagement pawls 364. Furthermore, thebumps 391 have a circumferential width in the circumferential direction that is larger than that of theengagement teeth 360 a. - In the illustrated embodiment, the
front sprocket 328 has anannular section 383 that has the sprocket teeth formed on the outer peripheral portion, and acylindrical section 385 integrally formed on the inner peripheral portion of theannular section 383. Thefront sprocket 328 is movably attached to the innerperipheral surface 379 a of thesprocket mounting portion 379. Thefront sprocket 328 rotates about the rotational axis X1 of thecrank axle 314. Thus, the rotational axis of the crank axle 314 (e.g., a first rotational axis) and the rotational axis of the front sprocket 328 (e.g., a second rotational axis) are coincident with each other. However, of course, it will be apparent to those skilled in the art from this disclosure thatfront sprocket 328 and thecrank axle 314 can be arranged with respect to each other such that the rotational axes of thefront sprocket 328 and thecrank axle 314 are offset with respect to each other. Thefront sprocket 328 has theengagement teeth 360 a on the innerperipheral surface 385 a of thecylindrical section 385. - Furthermore, as shown in
FIGS. 13A to 13M , thefront sprocket 328 has a plurality ofprojections 389. In particular, theprojections 389 are circumferentially arranged on an outerperipheral surface 385 b of thecylindrical section 385. Thesprocket mounting portion 379 of thetorque combining mechanism 336 has a plurality ofrecesses 387. In particular, therecesses 387 are circumferentially arranged on the innerperipheral surface 379 a of thesprocket mounting portion 379. Therecesses 387 and theprojections 389 are arranged relative to each other with circumferential spacings therebetween, respectively, to provide a limited range of relative rotation between thesprocket mounting portion 379 of thetorque combining mechanism 336 and thefront sprocket 328. In the illustrated embodiment, as shown inFIGS. 13B to 13E , andFIGS. 13H to 13K , therecesses 387 have first insidesurfaces 387 a, respectively, that circumferentially contact with first contact surfaces 389 a of theprojections 389, respectively, as thecrank axle 314 rotates in the forward rotational direction such that a rotation of thecrank axle 314 in the forward rotational direction is transmitted from thesprocket mounting portion 379 of thetorque combining mechanism 336 to thefront sprocket 328. Furthermore, as shown inFIGS. 13A and 13G , therecesses 387 have second insidesurfaces 387 b, respectively, that circumferentially contact with second contact surfaces 389 b of theprojections 389, respectively, while thecrank axle 314 is stationary. In particular, as shown inFIGS. 13A and 13G , thefront sprocket 328 is circumferentially biased in the clockwise direction with respect to thesprocket mounting portion 379 with a biasing or returnspring 393. Furthermore, thefront sprocket 328 is circumferentially biased with respect to thesprocket mounting portion 379 such that theengagement surface 360 b of each of theengagement teeth 360 a of thefront sprocket 328 are disposed in the forward rotational direction of thecrank axle 314 with respect to theslope surface 391 a of corresponding one of thebumps 391 of thesprocket mounting portion 379 while thecrank axle 314 is stationary. - In the illustrated embodiment, the
sprocket mounting portion 379 of thetorque combining mechanism 336 has therecesses 387, while thefront sprocket 328 has theprojections 389. However, alternatively, thesprocket mounting portion 379 of thetorque combining mechanism 336 can have a plurality of projections, while thefront sprocket 328 can have a plurality of recesses. In this case, the recesses and the projections are arranged relative to each other with circumferential spacings therebetween, respectively, to provide a limited range of relative rotation between thesprocket mounting portion 379 of thetorque combining mechanism 336 and thefront sprocket 328. - With this
drive unit 310, as shown inFIG. 12 , the torque generated by the pedaling force in the forward rotational direction is transmitted in the following transmission passage: the crankarms 101→thecrank axle 314→the firstrotation transmitting member 316→the secondrotation transmitting member 320→the thirdrotation transmitting member 326→the gear shiftingmain body 332 b→thefirst gear member 376→thesecond gear member 378. On the other hand, the output torque of themotor 330 is transmitted in the following path: thereduction gear unit 334→atorque transmitting member 370→the one-way clutch 380→thesecond gear member 378. Thesecond gear member 378 combines these two torques to transmit them to thefront sprocket 328. - Specifically, as shown in
FIGS. 13A and 13G , while thecrank axle 314 is stationary, thefront sprocket 328 is circumferentially biased with respect to thesprocket mounting portion 379 such that the second inside surfaces 387 b of therecesses 387 circumferentially contact with the second contact surfaces 389 b of theprojections 389, respectively. Furthermore, while thecrank axle 314 is stationary, theengagement surface 360 b of each of theengagement teeth 360 a of thefront sprocket 328 are disposed in the forward rotational direction of thecrank axle 314 with respect to theslope surface 391 a of corresponding one of thebumps 391 of thesprocket mounting portion 379. - As shown in
FIGS. 13B to 13E and 13H to 13K, when thecrank axle 314 is rotated in the forward rotational direction, thesecond gear member 378 rotates in the clockwise direction with respect to thefront sprocket 328 until the firstinside surfaces 387 a of therecesses 387 circumferentially contact with the first contact surfaces 389 a of theprojections 389, respectively. When the firstinside surfaces 387 a of therecesses 387 circumferentially contact with the first contact surfaces 389 a of theprojections 389, respectively, the rotation of thesecond gear member 378 is transmitted to thefront sprocket 328, which rotate thesecond gear member 378 and thefront sprocket 328 together in the forward rotational directions. Thebumps 391 of thecontrol part 368 and theengagement teeth 360 a of thetoothed part 360 are arranged with respect to each other such that thebumps 391 of thecontrol part 368 are axially aligned withengagement teeth 360 a of thetoothed part 360 while the firstinside surfaces 387 a of therecesses 387 circumferentially contact with the first contact surfaces 389 a of theprojections 389, respectively. Thus, as shown inFIGS. 13H to 13K , theengagement pawls 364 slide over thebumps 391 of thecontrol part 368 while pivoting between the engagement position and the release position as thecrank axle 314 rotates in the forward rotational direction, which prevents theengagement pawls 364 from engaging with theengagement teeth 360 a of thetoothed part 360. Specifically, the forward rotational speed of thesecond gear member 378 is faster than the forward rotational speed of thecrank axle 314 while the speed ratio of thesecond gear member 378 relative to the crankaxle 314 is larger than one due to a selection of the gear ratios of thegear shifting mechanism 332. In this case, theengagement pawls 364 relatively slide over thebumps 391 of thecontrol part 368 in the rearward rotational direction in order as illustrated inFIGS. 13H , 13I, 13J and 13K. On the other hand, the forward rotational speed of thesecond gear member 378 is slower than the rotational speed of thecrank axle 314 while the speed ratio of thesecond gear member 378 relative to the crankaxle 314 is smaller than one due to a selection of the gear ratios of thegear shifting mechanism 332. In this case, theengagement pawls 364 relatively slide over thebumps 391 of thecontrol part 368 in the forward rotational direction in order as illustrated inFIGS. 13K , 13J, 13I and 13H. Therefore, theclutch mechanism 338 allows a relative rotation between thecrank axle 314 and thefront sprocket 328 in the forward rotational direction. - On the other hand, with this
drive unit 10, the rearward rotation of thecrank arms 101 is also transmitted to thefront sprocket 328 to rotate thefront sprocket 328 in the rearward rotational direction. Specifically, the torque generated by the pedaling force in the rearward rotational direction is transmitted in the following transmission passage: the crankarms 101→thecrank axle 314→theclutch mechanism 338→thefront sprocket 328. The rearward rotation of thecrank arms 101 is not transmitted to thesecond gear member 378 via thegear shifting mechanism 332 by the operation of a one-way clutch disposed in thegear shifting mechanism 332. - As shown in
FIGS. 13F , 13L and 13M, when thecrank axle 314 is stopped, thefront sprocket 328 is rotated with respect to thesprocket mounting portion 379 in the clockwise direction with the biasing force of thereturn spring 393. With this biasing force, thefront sprocket 328 is rotated with respect to thesprocket mounting portion 379 such that the second inside surfaces 387 b of therecesses 387 circumferentially contact with the second contact surfaces 389 b of theprojections 389, respectively. When the second inside surfaces 387 b of therecesses 387 circumferentially contact with the second contact surfaces 389 b of theprojections 389, respectively, theengagement surface 360 b of each of theengagement teeth 360 a of thefront sprocket 328 are disposed in the forward rotational direction of thecrank axle 314 with respect to theslope surface 391 a of corresponding one of thebumps 391 of thesprocket mounting portion 379. Thus, when crankaxle 314 is rotated in the rearward rotational direction, the engagement ends 364 a of theengagement pawls 364 engage with the engagement surfaces 360 b of theengagement teeth 360 a of thefront sprocket 328, which rotates thefront sprocket 328 in the rearward rotational direction together with thesprocket mounting portion 379. Accordingly, the rearward rotation of thecrank arms 101 is transmitted to thefront sprocket 328 to rotate thefront sprocket 328 in the rearward rotational direction, thereby operating thecoaster brake 104 a of therear hub 104. - Referring now to
FIG. 14 , adrive unit 410 in accordance with a third embodiment will now be explained. - In view of the similarity between the first and third embodiments, the parts of the third embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment. In any event, the descriptions of the parts of the third embodiment that are substantially identical to the parts of the first embodiment may be omitted for the sake of brevity. However, it will be apparent to those skilled in the art from this disclosure that the descriptions and illustrations of the first embodiment also apply to this third embodiment, except as discussed and/or illustrated herein.
- Basically, the
drive unit 410 is arranged in a vicinity of the crank arms 101 (seeFIG. 1 ). In the illustrated embodiment, as shown inFIG. 14 , thedrive unit 410 has ahousing 412, acrank axle 414, a firstrotation transmitting member 416, anintermediate axle 418, a secondrotation transmitting member 420, a thirdrotation transmitting member 426 and a front sprocket 428 (e.g., a sprocket). As shown inFIG. 14 , thedrive unit 410 has amotor 430, atorque combining mechanism 436, and aclutch mechanism 438. Thus, thebicycle drive unit 410 includes themotor 430, thecrank axle 414, thetorque combining mechanism 436, and theclutch mechanism 438. - In the illustrated embodiment, the
crank axle 414 and thefront sprocket 428 are identical to the crankaxle 314 and thefront sprocket 328 in accordance with the second embodiment. Thus, the detailed configurations will be omitted for the sake of brevity. Furthermore, theclutch mechanism 438 is identical to theclutch mechanism 338 in accordance with the second embodiment, except that parts of theclutch mechanism 438 corresponding to parts of theclutch mechanism 338 that are disposed on thesprocket mounting portion 379 are disposed on asprocket mounting portion 479 that is fixedly coupled to anaxially extending sleeve 444 of thetorque combining mechanism 436. However, it will be apparent to those skilled in the art from this disclosure how theclutch mechanism 338 in accordance with the second embodiment can be applied to in thedrive unit 410 in accordance with the third embodiment. Thus, the detailed configurations will be omitted for the sake of brevity. - The
housing 412 mainly accommodates the firstrotation transmitting member 416, theintermediate axle 418, the secondrotation transmitting member 420, the thirdrotation transmitting member 426, themotor 430, and thetorque combining mechanism 436. Thehousing 412 also rotatably supports thecrank axle 414 by a pair of bearings in a conventional manner. Thecrank axle 414 extends through thehousing 412. - The
crank axle 414 is rotatable about a rotational axis X1 (e.g., a first rotational axis). The firstrotation transmitting member 416 has afirst gear 416 a that is fixedly coupled to the crankaxle 414. Theintermediate axle 418 is rotatably supported inside thehousing 412 by a pair of bearings. The secondrotation transmitting member 420 has alarge gear 420 a and asmall gear 420 b. The thirdrotation transmitting member 426 has athird gear 426 a. The front sprocket 428 (e.g., a sprocket) is identical to thefront sprocket 328 in accordance with the second embodiment. Thefront sprocket 428 rotates about the rotational axis X1 of thecrank axle 414. Thus, the rotational axis of the crank axle 414 (e.g., a first rotational axis) and the rotational axis of the front sprocket 428 (e.g., a second rotational axis) are coincident with each other. - In the illustrated embodiment, the
motor 430 is an inner rotor-type motor. Themotor 430 has arotor 430 a and astator 430 b. Since themotor 430 has a conventional configuration, the detailed description will be omitted for the sake of brevity. Thestator 430 b is fixedly coupled to an inner side surface of thehousing 412. Therotor 430 a is fixedly coupled to adrive shaft 430 c of themotor 430. Thedrive shaft 430 c is rotatably supported relative to the housing by a pair of bearings. - The
third gear 426 a of the thirdrotation transmitting member 426 is fixedly coupled to a distal end of thedrive shaft 430 c of themotor 430. Thethird gear 426 a also meshes with thelarge gear 420 a of the secondrotation transmitting member 420. Thelarge gear 420 a is rotatably coupled to theintermediate axle 418 via a one-way clutch 440. The one-way clutch 440 only transmits rotational output of themotor 430 for the forward rotation of thefront sprocket 428 to theintermediate axle 418. Thesmall gear 420 b is fixedly coupled to theintermediate axle 418. - The
torque combining mechanism 436 is operatively coupled to themotor 430 and thecrank axle 414 to combine rotational outputs of themotor 430 and thecrank axle 414. Thetorque combining mechanism 436 has acasing portion 442 and anaxially extending sleeve 444. Thetorque combining mechanism 436 is rotatably supported on thecrank axle 414 by a bearing. Thecasing portion 442 has anouter gear 446 on an outer peripheral surface of thecasing portion 442. Theouter gear 446 meshes with thesmall gear 420 b of the secondrotation transmitting member 420. Thecasing portion 442 is rotatably coupled to the firstrotation transmitting member 416 via a one-way clutch 448. In particular, the one-way clutch 448 is disposed between to an inner peripheral surface of thecasing portion 442 and thefirst gear 416 a of the firstrotation transmitting member 416. The one-way clutch 448 only transmits the forward rotation of thecrank axle 414 to thecasing portion 442 of thetorque combining mechanism 436. Thus, thetorque combining mechanism 436 combines the rotational output of themotor 430 transmitted to theouter gear 446 of thecasing portion 442 and the rotational output of thecrank axle 414 transmitted from thefirst gear 416 a via the one-way clutch 448. Theaxially extending sleeve 444 has atorque sensor 450 with a pair ofmagnetic deflection elements 450 a and a pair ofcoils 450 b that radially face with each other, respectively. The torque detected by thetorque sensor 450 is used to control the rotational output of themotor 430. Of course, it will be apparent to those skilled in the art from this disclosure that thetorque sensor 450 can be other type of torque sensors. - The
sprocket mounting portion 479 is configured to be operatively attached to the front sprocket 428 (e.g., a sprocket) such that thefront sprocket 428 rotates about the rotational axis X1 (e.g., a second rotational axis of a sprocket) in the forward rotational direction (e.g., a first direction) as thecrank axle 414 rotates about the rotational axis X1 in the forward rotational direction. Thesprocket mounting portion 479 is fixedly coupled to a distal end of theaxially extending sleeve 444 such thatsprocket mounting portion 479 rotates together with thetorque combining mechanism 436. Thesprocket mounting portion 479 is identical to thesprocket mounting portion 379 in accordance with the second embodiment. Thus, the detailed configuration will be omitted for the sake of brevity. - The
clutch mechanism 438 is operatively disposed between thecrank axle 414 and thefront sprocket 428. Theclutch mechanism 438 is configured to rotate thefront sprocket 428 about the rotational axis X1 (e.g., a second rotational axis) in the rearward rotational direction (e.g., a second direction) as thecrank axle 414 rotates about the rotational axis X1 in the rearward rotational direction. The rearward rotational direction is opposite the forward rotational direction. - With this
drive unit 410, the torque generated by the pedaling force in the forward rotational direction is transmitted in the following transmission passage: the crankarms 101→thecrank axle 414→the firstrotation transmitting member 416→the one-way clutch 448→thetorque combining mechanism 436. On the other hand, the output torque of themotor 430 is transmitted in the following path: the thirdrotation transmitting member 426→the secondrotation transmitting member 420→thetorque combining mechanism 436. Thetorque combining mechanism 436 combines these two torques to transmit them to thefront sprocket 428 via thesprocket mounting portion 479. Thus, the forward rotation of thecrank arms 101 is transmitted to thefront sprocket 428 after being assisted by themotor 430. The torque transmission from thesprocket mounting portion 479 to thefront sprocket 428 is identical to the torque transmission from thesprocket mounting portion 379 to thefront sprocket 328 in accordance with the second embodiment. Thus, the detailed description will be omitted for the sake of brevity. - On the other hand, with this
drive unit 410, the rearward rotation of thecrank arms 101 is also transmitted to thefront sprocket 428 to rotate thefront sprocket 428 in the rearward rotational direction. Specifically, the torque generated by the pedaling force in the rearward rotational direction is transmitted in the following transmission passage: the crankarms 101→thecrank axle 414→theclutch mechanism 438→thefront sprocket 428. The rearward rotation of thecrank arms 101 is not transmitted to thecasing portion 442 of thetorque combining mechanism 436 via the firstrotation transmitting member 416 by the operation of the one-way clutch 448. The torque transmission from theclutch mechanism 438 to thefront sprocket 428 is identical to the torque transmission from theclutch mechanism 338 to thefront sprocket 328 in accordance with the second embodiment. Thus, the detailed description will be omitted for the sake of brevity. - Referring now to
FIG. 15 , adrive unit 510 in accordance with a fourth embodiment will now be explained. - In view of the similarity between the first and fourth embodiments, the parts of the fourth embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment. In any event, the descriptions of the parts of the fourth embodiment that are substantially identical to the parts of the first embodiment may be omitted for the sake of brevity. However, it will be apparent to those skilled in the art from this disclosure that the descriptions and illustrations of the first embodiment also apply to this fourth embodiment, except as discussed and/or illustrated herein.
- As shown in
FIG. 2 , thedrive unit 10 in accordance with the first embodiment includes thegear shifting mechanism 32 and theclutch mechanism 38 that transmit the rotation of theinput part 64 caused by the forward rotation of the crank axle 14 to theoutput part 68 such that thefront sprocket 28 rotates in the forward rotational direction. Thegear shifting mechanism 32 and theclutch mechanism 38 also transmit the rotation of theinput part 64 caused by the rearward rotation of the crank axle 14 to theoutput part 68 such that the front sprocket rotates in the rearward rotational direction. The drive unit in accordance with the present application can include any types of gear shifting mechanisms and the clutch mechanism having the above-mentioned feature. For example, as shown inFIG. 15 , thedrive unit 510 in accordance with the fourth embodiment has agear shifting mechanism 532 and theclutch mechanism 538. Thisgear shifting mechanism 532 and theclutch mechanism 538 is basically identical to the internally mounted hub transmission disclosed in European Patent No.EP 1 700 780 B1, except that thegear shifting mechanism 532 and theclutch mechanism 538 are installed in thedrive unit 510. Thedrive unit 510 is also identical to thedrive unit 10 shown inFIG. 2 , except that thedrive unit 510 has thegear shifting mechanism 532 and theclutch mechanism 538 instead of thegear shifting mechanism 32 and theclutch mechanism 38. Thus, detailed description of thegear shifting mechanism 532, theclutch mechanism 538 and thedrive unit 510 will be omitted for the sake of brevity. Thisgear shifting mechanism 532 and theclutch mechanism 538 selectively establishes three gear ratios for the forward rotation of thefront sprocket 28 and one gear ratio of the rearward rotation of thefront sprocket 28. - The
gear shifting mechanism 532 mainly includes asupport axle 522, aninput part 564, aplanetary gear unit 566, and anoutput part 568. The rotation of the third rotation transmitting member 26 (seeFIG. 2 ) is transmitted to theinput part 564, theplanetary gear unit 566 and theoutput part 568. Theinput part 564, theplanetary gear unit 566 and theoutput part 568 are rotatably supported on thesupport axle 522, respectively. - Specifically, the
input part 564 is rotatably supported on thesupport axle 522 and operatively coupled to the crank axle 14 (seeFIG. 2 ). Thesecond sprocket 26 a of the third rotation transmitting member 26 (seeFIG. 2 ) is fixedly coupled to theinput part 564 such that they can rotate together. Theplanetary gear unit 566 is disposed between theinput part 564 and theoutput part 568. Theplanetary gear unit 566 selectively establishes a plurality of (e.g., three) gear ratios. Theplanetary gear unit 566 transmits power between theinput part 564 and theoutput part 568. Theoutput part 568 is rotatably supported on thesupport axle 522 and operatively coupled to the torque combining mechanism 36 (seeFIG. 2 ). Theoutput part 568 outputs the rotation after changing the rotational speed by theplanetary gear unit 566 to the torque combining mechanism 36 (seeFIG. 2 ). Thefirst gear member 76 of the torque combining mechanism 36 (seeFIG. 2 ) is coupled to theoutput part 568. - The
gear shifting mechanism 532 further has aroller brake 577, which itself is known as a coaster brake unit. When the clank axle 14 is rotated in the rearward rotational direction, the rearward rotational power is transmitted to theplanetary gear unit 566 and causes theroller brake 577 to rotate rearward. - The
drive unit 510 further has aclutch mechanism 538 that is operatively disposed between the crank axle 14 and the front sprocket 28 (seeFIG. 2 ). Theclutch mechanism 538 is configured to rotate thefront sprocket 28 in the rearward rotational direction as the crank axle 14 rotates in the rearward rotational direction. Theclutch mechanism 538 is supported to thesupport axle 522 of thegear shifting mechanism 532 such that theclutch mechanism 538 is operatively disposed between aplanetary gear carrier 566 a of theplanetary gear unit 566 and theoutput part 568 of thegear shifting mechanism 532. Specifically, as shown inFIG. 15 , abrake cup 580 carries theroller brake 577, an innerfree gear 582, an outerfree gear 584, and a one-way clutch 586 between the inner and outerfree gears clutch mechanism 538. The outerfree gear 584 is fixedly coupled to the housing 12 (seeFIG. 2 ). The one-way clutch 586 is configured to transmit a rearward rotational force from thebrake cup 580 to the outerfree gear 584. As a result, theroller brake 577 transmits the rearward rotational power to theoutput part 568 such that thefront sprocket 28 rotates in the rearward rotational direction. - In the illustrated embodiment, the
gear shifting mechanism - In understanding the scope of the present invention, the term “coupled” or “coupling”, as used herein, encompasses configurations in which an element is directly secured to another element by affixing the element directly to the other element; configurations in which the element is indirectly secured to the other element by affixing the element to the intermediate member(s) which in turn are affixed to the other element; and configurations in which one element is integral with another element, i.e. one element is essentially part of the other element. This definition also applies to words of similar meaning, for example, “joined”, “connected”, “attached”. “mounted”, “bonded”, “fixed” and their derivatives.
- In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives.
- Also it will be understood that although the terms “first” and “second” may be used herein to describe various components these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, for example, a first component discussed above could be termed a second component and vice-a-versa without departing from the teachings of the present invention. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. 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.
- While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, the size, shape, location or orientation of the various components can be changed as needed and/or desired so long as they do not substantially their intended function. Components that are shown directly connected or contacting each other can have intermediate structures disposed between them unless specifically stated otherwise. The functions of one element can be performed by two, and vice versa unless specifically stated otherwise. The structures and functions of one embodiment can be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
Claims (23)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/761,516 US8777791B1 (en) | 2013-02-07 | 2013-02-07 | Bicycle drive unit |
TW102125981A TWI584997B (en) | 2013-02-07 | 2013-07-19 | Bicycle drive unit |
CN201310365306.2A CN103979062B (en) | 2013-02-07 | 2013-08-21 | Bicycle drive unit |
DE102014000898.3A DE102014000898A1 (en) | 2013-02-07 | 2014-01-23 | Bicycle drive unit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/761,516 US8777791B1 (en) | 2013-02-07 | 2013-02-07 | Bicycle drive unit |
Publications (2)
Publication Number | Publication Date |
---|---|
US8777791B1 US8777791B1 (en) | 2014-07-15 |
US20140221151A1 true US20140221151A1 (en) | 2014-08-07 |
Family
ID=51135587
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/761,516 Active 2033-02-23 US8777791B1 (en) | 2013-02-07 | 2013-02-07 | Bicycle drive unit |
Country Status (4)
Country | Link |
---|---|
US (1) | US8777791B1 (en) |
CN (1) | CN103979062B (en) |
DE (1) | DE102014000898A1 (en) |
TW (1) | TWI584997B (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150336631A1 (en) * | 2014-05-21 | 2015-11-26 | Shimano Inc. | Bicycle drive unit |
US20160339993A1 (en) * | 2015-05-18 | 2016-11-24 | GM Global Technology Operations LLC | Electric bike powertrain with dual planetary gear sets and ring gear pedal reaction torque measurement |
JP2017019446A (en) * | 2015-07-14 | 2017-01-26 | パナソニックIpマネジメント株式会社 | Power-assisted bicycle |
JPWO2016030921A1 (en) * | 2014-08-27 | 2017-06-08 | パナソニックIpマネジメント株式会社 | Electric assist bicycle |
US9976630B2 (en) * | 2016-05-20 | 2018-05-22 | Kim Leung Luk | Smart gearing system for bicycle |
WO2021129066A1 (en) * | 2019-12-28 | 2021-07-01 | 苏州万佳电器有限公司 | Central drive device and bicycle having said device |
Families Citing this family (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102012007166B3 (en) * | 2012-04-07 | 2013-06-06 | Franz Schneider Gmbh & Co Kg | Drive for a pedal vehicle, especially for children |
JP5628880B2 (en) * | 2012-10-25 | 2014-11-19 | 株式会社シマノ | Drive unit |
WO2015008314A1 (en) * | 2013-07-16 | 2015-01-22 | パナソニックIpマネジメント株式会社 | Electric assist bicycle |
US9434447B2 (en) * | 2014-02-05 | 2016-09-06 | 3G Bikes, Llc | Bicycle with electric motor assist |
JP5969568B2 (en) * | 2014-10-16 | 2016-08-17 | 株式会社シマノ | Bicycle assist unit |
JP6538393B2 (en) * | 2015-03-25 | 2019-07-03 | 株式会社シマノ | Bicycle transmission |
TWI582011B (en) * | 2015-03-30 | 2017-05-11 | Bicycle in the home of the dual motor less gear difference planetary gears | |
US10689056B2 (en) * | 2015-04-14 | 2020-06-23 | Matthew Hendey | Apparatus, systems, and methods for preventing migration of contaminants within tubing of a frame |
JP6514995B2 (en) * | 2015-08-31 | 2019-05-15 | 株式会社シマノ | Bicycle guard and drive unit having the same |
DE102015217013A1 (en) * | 2015-09-04 | 2017-03-09 | Volkswagen Aktiengesellschaft | Gear arrangement and drive arrangement for a vehicle |
JP2017088091A (en) * | 2015-11-16 | 2017-05-25 | 株式会社シマノ | Drive unit for bicycle |
JP6515017B2 (en) * | 2015-11-27 | 2019-05-15 | 株式会社シマノ | Bicycle drive unit |
JP6515019B2 (en) * | 2015-11-30 | 2019-05-15 | 株式会社シマノ | Bicycle drive unit |
JP7148219B2 (en) * | 2016-04-28 | 2022-10-05 | ヤマハ発動機株式会社 | electric assisted bicycle |
JP6679404B2 (en) * | 2016-04-28 | 2020-04-15 | ヤマハ発動機株式会社 | Drive unit and electric bicycle |
DE102016225165A1 (en) * | 2016-12-15 | 2018-06-21 | Zf Friedrichshafen Ag | Gear for a bike |
DE102017212347A1 (en) | 2017-07-19 | 2019-01-24 | Robert Bosch Gmbh | Bottom bracket drive of a bicycle |
JP6867547B2 (en) * | 2018-03-05 | 2021-04-28 | 本田技研工業株式会社 | Bicycle power generator and bicycle |
DE102018217351B4 (en) * | 2018-10-10 | 2023-01-12 | Vitesco Technologies Germany Gmbh | Drive device for a bicycle with an electric motor and bicycle with a corresponding drive device |
JP6735807B2 (en) * | 2018-12-19 | 2020-08-05 | 本田技研工業株式会社 | Drive unit |
CN113692377B (en) * | 2019-02-17 | 2022-08-09 | A·诺维科夫 | Bicycle propulsion system for electric bicycle converter |
NO20191502A1 (en) * | 2019-12-19 | 2021-06-21 | Ca Tech Systems As | Pedally propelled vehicle drive system |
NL2035167A (en) * | 2022-10-07 | 2024-04-17 | Classified Cycling Bv | Actuatable bidirectional clutch mechanism for a bicycle transmission |
Family Cites Families (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS52505B2 (en) | 1972-10-13 | 1977-01-08 | ||
JP3547847B2 (en) | 1995-05-17 | 2004-07-28 | 本田技研工業株式会社 | Treading force detection device for bicycle with assist motor |
JP3146138B2 (en) | 1995-08-30 | 2001-03-12 | シャープ株式会社 | Reflective liquid crystal display device and information terminal equipment |
TW348138B (en) * | 1996-07-03 | 1998-12-21 | Yamaha Motor Co Ltd | Electric motor assisted vehicle |
JPH1016857A (en) * | 1996-07-05 | 1998-01-20 | Yamaha Motor Co Ltd | Motor-assisted vehicle |
TW371646B (en) * | 1996-09-26 | 1999-10-11 | Mistubishi Heavy Ind Ltd | Driving unit for an electric motor driven bicycle |
US6196347B1 (en) * | 1998-09-22 | 2001-03-06 | Industrial Technology Research Institute | Power transmission and pedal force sensing system for an electric bicycle |
US6296072B1 (en) * | 1999-01-20 | 2001-10-02 | Opti-Bike Llc | Electric bicycle and methods |
US6380731B1 (en) | 1999-11-24 | 2002-04-30 | Shimano, Inc. | Motor unit with an integrated speed sensor for a bicycle hub transmission |
US6607465B1 (en) | 2000-03-10 | 2003-08-19 | Shimano, Inc. | Bicycle hub transmission with a guiding member for a sun gear |
US6516908B2 (en) * | 2001-05-10 | 2003-02-11 | Merida Industry Co., Ltd. | Transmission for an electric bicycle |
US7059989B2 (en) * | 2004-06-30 | 2006-06-13 | Shimano Inc. | Bottom bracket structure with dynamo |
DE602005006965D1 (en) | 2005-03-09 | 2008-07-03 | Shimano Kk | Drive hub with brake for a go-kart |
US7682283B2 (en) | 2007-11-20 | 2010-03-23 | Shimano, Inc. | Bicycle hub transmission with a power control mechanism for a shift assist mechanism |
CN101353076B (en) * | 2008-09-18 | 2012-07-18 | 李平 | Small electric vehicle central driver |
WO2011088722A1 (en) * | 2010-01-22 | 2011-07-28 | Foster Assets Corporation | Motor having integrated torque sensor |
US8590655B2 (en) * | 2010-01-22 | 2013-11-26 | Foster Assets Corporation | Pedal driven apparatus having a motor |
DE102010017917A1 (en) | 2010-04-21 | 2011-10-27 | Daum Gmbh & Co. Kg | Power transmission unit |
JP2012051446A (en) * | 2010-08-31 | 2012-03-15 | Honda Motor Co Ltd | Bicycle with auxiliary power unit |
CN103038128B (en) | 2010-09-16 | 2015-08-12 | 松下电器产业株式会社 | Electrical Bicycle |
JP5649549B2 (en) * | 2011-10-13 | 2015-01-07 | 株式会社シマノ | Bicycle drive unit |
US8651993B1 (en) * | 2012-09-10 | 2014-02-18 | Shimano Inc. | Bicycle drive unit |
-
2013
- 2013-02-07 US US13/761,516 patent/US8777791B1/en active Active
- 2013-07-19 TW TW102125981A patent/TWI584997B/en active
- 2013-08-21 CN CN201310365306.2A patent/CN103979062B/en active Active
-
2014
- 2014-01-23 DE DE102014000898.3A patent/DE102014000898A1/en active Granted
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150336631A1 (en) * | 2014-05-21 | 2015-11-26 | Shimano Inc. | Bicycle drive unit |
US10167047B2 (en) * | 2014-05-21 | 2019-01-01 | Shimano Inc. | Bicycle drive unit |
JPWO2016030921A1 (en) * | 2014-08-27 | 2017-06-08 | パナソニックIpマネジメント株式会社 | Electric assist bicycle |
US20160339993A1 (en) * | 2015-05-18 | 2016-11-24 | GM Global Technology Operations LLC | Electric bike powertrain with dual planetary gear sets and ring gear pedal reaction torque measurement |
US9802673B2 (en) * | 2015-05-18 | 2017-10-31 | GM Global Technology Operations LLC | Electric bike powertrain with dual planetary gear sets and ring gear pedal reaction torque measurement |
JP2017019446A (en) * | 2015-07-14 | 2017-01-26 | パナソニックIpマネジメント株式会社 | Power-assisted bicycle |
CN107428391A (en) * | 2015-07-14 | 2017-12-01 | 松下知识产权经营株式会社 | Electrically assisted bicycle |
EP3323703A4 (en) * | 2015-07-14 | 2018-08-15 | Panasonic Intellectual Property Management Co., Ltd. | Electric-assist bicycle |
US9976630B2 (en) * | 2016-05-20 | 2018-05-22 | Kim Leung Luk | Smart gearing system for bicycle |
WO2021129066A1 (en) * | 2019-12-28 | 2021-07-01 | 苏州万佳电器有限公司 | Central drive device and bicycle having said device |
Also Published As
Publication number | Publication date |
---|---|
CN103979062B (en) | 2016-08-17 |
DE102014000898A1 (en) | 2014-08-07 |
TW201431741A (en) | 2014-08-16 |
TWI584997B (en) | 2017-06-01 |
US8777791B1 (en) | 2014-07-15 |
CN103979062A (en) | 2014-08-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8777791B1 (en) | Bicycle drive unit | |
US9017201B2 (en) | Bicycle drive unit | |
US8376897B2 (en) | Internally geared hub for bicycle | |
US10137961B2 (en) | Bicycle drive unit | |
EP1595783B1 (en) | Bicycle internal gear shifting hub | |
JP5561586B2 (en) | Electric assist bicycle | |
US9227694B2 (en) | Bicycle drive unit | |
TW201634336A (en) | Bicycle drive unit and bicycle equipped with the drive unit | |
WO2018173695A1 (en) | Power unit for electrically assisted vehicle | |
JP3146138U (en) | Internal gear shifting hub for bicycles | |
US9228652B2 (en) | Bicycle drive unit | |
US10407129B2 (en) | Gear and bicycle gear change mechanism including gear | |
WO2018173697A1 (en) | Power unit for electrically assisted vehicle and assembly method thereof | |
EP1112922A2 (en) | Bicycle hub transmission | |
JP6179703B2 (en) | Electric hub device and electric bicycle | |
JP2002293285A (en) | Power unit for power-assisted bicycle | |
JP5442821B1 (en) | Bicycle drive unit | |
WO2024029381A1 (en) | Electric power assist unit for bicycle, and electric power assisted bicycle | |
WO2023248851A1 (en) | Power assist unit for bicycle and power assisted bicycle | |
WO2018173696A1 (en) | Power unit for electric vehicle |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: SHIMANO INC., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HINO, TETSUYA;SHOGE, AKIHIKO;ITO, MINORU;SIGNING DATES FROM 20130215 TO 20130221;REEL/FRAME:029857/0336 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551) Year of fee payment: 4 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 8 |