Transmission for a human-powered vehicle and the transmission-encompassing support system for a human-powered vehicle

Abstract

Transmission for a human-powered vehicle, the transmission comprising: a first gear unit comprising a first gear path that changes the speed of a rotation that is initiated; a second gear unit comprising a second gear path that changes the speed of a rotation that is initiated, wherein the second gear unit is configured to transmit rotation to the first gear unit; and a switching unit that changes the gear ratio of the human-powered vehicle in stages, wherein the first gear unit comprises a first planetary gear unit, The switching unit changes a rotational state of at least one of the first and second gear units in order to switch a transmission path of the rotation that is introduced into the first and second gear units. the transmission path comprises a first transmission path that passes through at least the first transmission path, a second transmission path that passes through the second transmission path without passing through the first transmission path, and a third transmission path that passes through both the first and second transmission paths; and The switching unit switches the transmission path in the sequence first transmission path, second transmission path and third transmission path in order to increase the translation ratio in steps.

Description

STATE OF THE ART

[0001] The present invention relates to a transmission for a human-powered vehicle and a support system for a human-powered vehicle comprising the transmission.

[0002] A transmission for a human-powered vehicle disclosed in Patent Document 1 includes an internal transmission device that changes the gear ratio of the human-powered vehicle in stages. The internal transmission device includes a first transmission unit and a second transmission unit. The transmission in Patent Document 1 changes the speed of rotation with the first transmission unit without changing the speed of rotation with the second transmission unit, and outputs the rotation to an output body in second and third transmission stages. In a fourth transmission stage and a fifth transmission stage that maintains the maximum gear ratio, the transmission in Patent Document 1 changes the speed of rotation with both the first transmission unit and the second transmission unit and outputs the rotation to the output body.

[0003] Patent Specification No. 1 Japanese Patent No. JP 4564978 SUMMARY OF THE INVENTION

[0004] In the transmission described above, one of the gear units, which is used once to increase the gear ratio, is continuously used for shifting to further increase the gear ratio. This reduces the degree of freedom for forming gear stages.

[0005] It is an object of the present invention to provide a transmission for a human-powered vehicle having a preferred configuration of gear stages and a support system for a human-powered vehicle comprising the transmission.

[0006] A transmission according to a first aspect of the present invention is for a transmission for a human-powered vehicle. The transmission includes a first transmission unit having a first transmission path that changes a speed of rotation being input, a second transmission unit having a second transmission path that changes a speed of rotation being input, the second transmission unit being configured to transmit rotation to the first transmission unit, and a switching unit that changes a gear ratio of the human-powered vehicle in steps. The first transmission unit includes a first planetary gear unit. The switching unit changes a rotation state of at least one of the first transmission unit and the second transmission unit to switch a transmission path of rotation input to the first transmission unit and the second transmission unit.The transmission path includes a first transmission path that passes through at least the first transmission path, a second transmission path that passes through the second transmission path without passing through the first transmission path, and a third transmission path that passes through both the first transmission path and the second transmission path. The switching unit switches the transmission path in the order of the first transmission path, the second transmission path, and the third transmission path to increase the transmission ratio in stages.

[0007] With the transmission according to the first aspect, in a case where the switching unit increases the gear ratio in stages, the second transmission path, which does not pass through the first transmission path of the first transmission unit, is provided between the first transmission path and the third transmission path, which pass through the first transmission path of the first transmission unit. Thus, the gear stages are configured in a preferred manner. With the transmission according to the first aspect, in a case of switching from the first transmission path to the second transmission path, hindrance to the switching of the transmission path caused by torque input to the first planetary gear unit is limited.

[0008] According to a second aspect of the present invention, the transmission according to the first aspect is configured such that the first transmission path includes a first path and a second path. The switching unit is configured to switch from one of the first transmission path including the first path and the first transmission path including the second path to the other of the first transmission path including the first path and the first transmission path including the second path in at least one of the first transmission path and the third transmission path. The gear ratio in a case where the first transmission path includes the second path is larger in each of the first transmission path and the third transmission path than that in a case where the first transmission path includes the first path.

[0009] With the transmission according to the second aspect, two gear stages are formed in at least one of the first transmission path and the third transmission path.

[0010] According to a third aspect of the present invention, the transmission according to the second aspect is configured such that the first planetary gear unit comprises at least two first sun gears, at least one first ring gear, at least two first planetary gears each meshing with the at least two first sun gears, and a first carrier that movably supports the at least two first planetary gears about the corresponding first sun gears. The switching unit is configured to change a rotational state of the at least two first sun gears such that the transmission path passes through one of the at least two first sun gears. The first path passes through one of the at least two first sun gears. The second path passes through the first sun gear that is different from the one of the at least two first sun gears that the first path passes through.

[0011] With the transmission according to the third aspect, the first path and the second path pass through different first sun gears, so that two transmission stages are formed in a preferred manner.

[0012] According to a fourth aspect of the present invention, the transmission according to the second aspect is configured such that the first transmission path further includes a third path. The switching unit is configured to switch from one of the first transmission path including the second path and the first transmission path including the third path to the other of the first transmission path including the second path and the first transmission path including the third path in at least one of the first transmission path and the third transmission path. The gear ratio in a case where the first transmission path includes the third path is larger in each of the first transmission path and the third transmission path than that in a case where the first transmission path includes the second path.

[0013] With the transmission according to the fourth aspect, three gear stages are formed in at least one of the first transmission path and the third transmission path.

[0014] According to a fifth aspect of the present invention, the transmission according to the third aspect is configured such that the first transmission path further includes a third path. The switching unit is configured to switch from one of the first transmission path including the second path and the first transmission path including the third path to the other of the first transmission path including the second path and the first transmission path including the third path in at least one of the first transmission path and the third transmission path. The gear ratio in a case where the first transmission path includes the third path is larger in each of the first transmission path and the third transmission path than that in a case where the first transmission path includes the second path. The first planetary gear unit includes at least three first sun gears.The third path passes through a first sun gear that is different from those of the at least three first sun gears that the first path and the second path pass through.

[0015] With the transmission according to the fifth aspect, the first path and the second path pass through different first sun gears, so that three transmission stages are formed in a preferred manner.

[0016] According to a sixth aspect of the present invention, the transmission according to any one of the first to fifth aspects is configured such that the transmission path further includes a fourth transmission path that transmits input rotation without changing the speed. The switching unit switches the transmission path in the order of the fourth transmission path, the first transmission path, the second transmission path, and the third transmission path to increase the gear ratio in stages.

[0017] With the transmission according to the sixth aspect, the number of gear stages is increased by the fourth transmission path, which transmits rotation that is initiated without changing the speed.

[0018] According to a seventh aspect of the present invention, the transmission according to the third or fifth aspect is configured such that the second transmission unit comprises a second planetary gear unit. The second planetary gear unit comprises at least one second sun gear, at least one second ring gear, at least one second planetary gear meshing with the at least one second sun gear, and a second carrier movably supporting the second planetary gear about the at least one second sun gear. The switching unit is configured to change a rotational state of the at least one second sun gear such that the transmission path passes through one of the at least one second sun gear. The first carrier and the second ring gear are connected by a transmission unit. The first carrier and the second carrier are connected by a first one-way clutch. Rotation of the second carrier rotates the first carrier with the first one-way clutch in the first transmission path.A rotation of the second ring gear rotates the first carrier with the transmission unit in the third transmission path.

[0019] With the transmission according to the seventh aspect, in the first transmission path, rotation of the second carrier is transmitted to the first carrier via the first one-way clutch in a preferred manner. In the third transmission path, rotation of the second ring gear is transmitted to the first carrier via the transmission unit in a preferred manner.

[0020] According to an eighth aspect of the present invention, the transmission according to the seventh aspect is configured such that the transmission path further includes a fourth transmission path that transmits rotation input without changing the speed. Rotation of the second carrier rotates the first carrier with the first one-way clutch, and rotation of the first carrier rotates the second ring gear with the transmission unit in the fourth transmission path.

[0021] With the transmission according to the eighth aspect, in the fourth transmission path, a rotation of the first carrier is transmitted to the second ring gear via the first one-way clutch in a preferential manner.

[0022] According to a ninth aspect of the present invention, the transmission according to the seventh aspect is configured such that the switching unit is configured to change a rotational state of the at least two first sun gears after changing a rotational state of the at least one second sun gear to increase the gear ratio in steps and switch the transmission path from the first transmission path to the second transmission path.

[0023] The transmission according to the ninth aspect avoids a situation in which the rotational state of the first sun gears is changed before the rotational state of the second sun gear is changed.

[0024] According to a tenth aspect of the present invention, the transmission according to the ninth aspect is configured such that the transmission unit includes one of a recess and a protrusion located at one of an outer peripheral portion of the first carrier and an inner peripheral portion of the second ring gear, and the other of the recess and the protrusion located at the other of the outer peripheral portion of the first carrier and the inner peripheral portion of the second ring gear. A length in a circumferential direction of the recess is greater than a length in a circumferential direction of the protrusion.

[0025] With the transmission according to the tenth aspect, rotation is transmitted in a preferable manner both in a case where rotation is transmitted from the first carrier to the second ring gear and in a case where rotation is transmitted from the second ring gear to the first carrier.

[0026] According to an eleventh aspect of the present invention, the transmission according to any one of the seventh to tenth aspects further comprises an output body, a second one-way clutch, and a third one-way clutch. The first ring gear is connected to the output body via the second one-way clutch. The second ring gear is connected to the output body via the third one-way clutch.

[0027] With the transmission according to the eleventh aspect, the transmission of rotation from the output body to the first ring gear is limited by the second one-way clutch, and the transmission from the output body to the second ring gear is limited by the third one-way clutch.

[0028] A transmission according to a twelfth aspect of the present invention is for a human-powered vehicle. The transmission includes a first transmission unit having a first transmission path that changes a speed of input rotation, a second transmission unit having a second transmission path that changes a speed of input rotation, the second transmission unit being configured to transmit rotation to the first transmission unit, and a switching unit that changes a gear ratio of the human-powered vehicle in steps. The first transmission unit includes a first planetary gear unit. The first transmission path includes a plurality of paths, each having a different gear ratio.The switching unit is configured to change a rotational state of at least one of the first transmission unit and the second transmission unit to switch a transmission path of the rotation input to the first transmission unit and the second transmission unit. The switching unit is configured to switch from one of the first transmission path including one of the plurality of paths and the first transmission path including another of the plurality of paths to the other of the first transmission path including one of the plurality of paths and the first transmission path including the other of the plurality of paths, such that the transmission path passes through the first transmission path.In a case where the gear ratio is increased in steps, between a gear stage formed by a transmission path passing through a first transmission path including one of the plurality of paths receiving a first gear ratio and a gear stage formed by a transmission path passing through the first transmission path including another one of the plurality of paths receiving a smaller gear ratio than the first gear ratio, a gear stage is formed by a transmission path not passing through the first transmission path.

[0029] With the transmission according to the twelfth aspect, in a case where the gear ratio is increased in stages, the gear ratio of a gear stage including one of the plurality of paths that maintains a gear ratio smaller than the first gear ratio is greater than the gear ratio of a gear stage including one of the plurality of paths that maintains the first gear ratio. Thus, the gear stages are configured in a preferred manner.

[0030] According to a thirteenth aspect of the present invention, the transmission according to any one of the first to twelfth aspects further comprises a hub that houses the first transmission unit, the second transmission unit, and the switching unit.

[0031] With the transmission according to the thirteenth aspect, gear stages are formed in a preferred manner in a transmission comprising a hub.

[0032] An assist system according to a fourteenth aspect of the present invention is for a human-powered vehicle. The assist system includes the transmission according to any one of the first to thirteenth aspects and a motor that assists human propulsion.

[0033] With the support system according to the fourteenth aspect, gear stages are configured in a preferred manner in a support system comprising a motor. With the transmission according to the fourteenth aspect, gear stages are configured in a preferred manner in a transmission configured to increase a torque of an introduced rotation with a motor.

[0034] According to a fifteenth aspect of the present invention, the assist system according to the fourteenth aspect further comprises an operating unit that is manually operated to operate the transmission. The transmission changes a gear ratio of the human-powered vehicle according to the operation of the operating unit.

[0035] With the assistance system according to the fifteenth aspect, in an assistance system comprising an actuating unit that is manually actuated, gear stages are formed in a preferred manner.

[0036] The transmission for a human-powered vehicle and the assist system for a human-powered vehicle comprising the transmission according to the present invention form gear stages in a preferred manner. BRIEF DESCRIPTION OF THE DRAWINGS Fig.1 is a side view of a human-powered vehicle including a human-powered vehicle transmission and a human-powered vehicle support system including the transmission in a first embodiment. Fig. 2 is a front view of the transmission for a human-powered vehicle used in Fig. 1 is shown. Fig. 3 is a cross-sectional view taken along line D3-D3 in Fig. 2. Fig. 4 is a cross-sectional view taken along line D4-D4 in Fig. 3. Fig. 5 is a front view of the Fig. 3 shown switching unit. Fig. 6 is a cross-sectional view taken along line D6-D6 in Fig. 3. Fig. 7 is a cross-sectional view taken along line D7-D7 in Fig. 3. Fig. 8 is a perspective view of the Fig.3 shown arm element. Fig. 9 is a side view of the Fig. 3 shown arm element. Fig. 10 is a partial cross-sectional view showing a state in which driving force is transmitted from a first carrier to a second ring gear in the switching unit shown in Fig. 4 is shown. Fig. Fig. 11 is a partial cross-sectional view showing a state in which driving force is transmitted from the second ring gear to the first carrier in the switching unit shown in Fig. 4 is shown. Fig. 12 is a schematic diagram showing a transmission run of the Fig. 3 shows the transmission of the human-powered vehicle in a first gear stage. Fig. 13 is a schematic diagram showing a transmission run of the Fig.3 shows the transmission of the human-powered vehicle in a second gear stage. Fig. 14 is a schematic diagram showing a transmission run of the Fig. 3 shows the transmission of the human-powered vehicle in a third gear stage. Fig. 15 is a schematic diagram showing a transmission run of the Fig. 3 shows the transmission of the human-powered vehicle in a fourth gear stage. Fig. 16 is a schematic diagram showing a transmission run of the Fig. 3 shows the transmission of the human-powered vehicle in a fifth gear stage. Fig. 17 is a side view of an arm member in a second embodiment. Fig.18 is a schematic diagram showing a transmission flow of the transmission of the human-powered vehicle of the second embodiment in a first gear stage. Fig. 19 is a schematic diagram showing a transmission flow of the transmission of the human-powered vehicle of the second embodiment in a second gear stage. Fig. 20 is a schematic diagram showing a transmission flow of the transmission of the human-powered vehicle of the second embodiment in a third gear stage. Fig. 21 is a schematic diagram showing a transmission flow of the transmission of the human-powered vehicle of the second embodiment in a fourth gear stage. Fig.22 is a schematic diagram showing a transmission flow of the transmission of the human-powered vehicle of the second embodiment at a fifth gear stage. Fig. 23 is a schematic diagram showing a transmission flow of the transmission of the human-powered vehicle of the second embodiment in a sixth gear stage. Fig. 24 is a schematic diagram showing a transmission flow of the transmission of the human-powered vehicle of the second embodiment at a seventh gear stage. Fig. 25 is a schematic diagram showing a transmission flow of the transmission of the human-powered vehicle of the second embodiment at an eighth gear stage. EMBODIMENTS OF THE INVENTIONFirst Embodiment

[0037] With reference to the Fig.1 to 16, a first embodiment of a human-powered vehicle assistance system 40 and a transmission 50 for a human-powered vehicle will now be described. A human-powered vehicle 10 is a vehicle that can be propelled by at least human propulsion. The number of wheels on the human-powered vehicle 10 is not limited. The human-powered vehicle 10 includes, for example, a unicycle and a vehicle having three or more wheels. The human-powered vehicle 10 includes, for example, various types of bicycles, such as a mountain bike, a road bike, a city bike, a cargo bike, a recumbent bike, and an electric bicycle (e-bike). The electric bicycle includes an electrically assisted bicycle that assists the propulsion of the vehicle with an electric motor.In the embodiments described below, the human-powered vehicle 10 refers to a bicycle.

[0038] The human-powered vehicle 10 includes a crank 12 to which human driving power is input, wheels 14, and a vehicle body 16. The wheels 14 include a rear wheel 14A and a front wheel 14B. The vehicle body 16 includes a frame 18. The crank 12 includes a crank axle 12A configured to rotate relative to the frame 18, and crank arms 12B provided at opposite axial ends of the crank axle 12A. A pedal 20 is coupled to each of the crank arms 12B. The rear wheel 14A is driven according to the rotation of the crank 12. The rear wheel 14A is supported by the frame 18. The crank 12 and the rear wheel 14A are connected to each other by a drive mechanism 22. The drive mechanism 22 includes a first rotating body 24 coupled to the crank axle 12A. The crankshaft 12A and the first rotating body 24 can be coupled to each other via a first one-way clutch.The first one-way clutch is configured to allow forward rotation of the first rotating body 24 when the crank 12 rotates forward and to prohibit reverse rotation of the first rotating body 24 when the crank 12 rotates backward. The first rotating body 24 includes a gear, a pulley, or a bevel gear. The drive mechanism 22 further includes a second rotating body 26 and a connecting element 28. The connecting element 28 transmits rotational force of the first rotating body 24 to the second rotating body 26. The connecting element 28 includes, for example, a chain, a belt, or a shaft.

[0039] The second rotating body 26 is coupled to the rear wheel 14A. The second rotating body 26 comprises a gear, a pulley, or a bevel gear. Preferably, a one-way clutch is provided between the second rotating body 26 and the rear wheel 14A. The one-way clutch is configured to allow forward rotation of the rear wheel 14A when the second rotating body 26 rotates forward and to prevent reverse rotation of the rear wheel 14A when the second rotating body 26 rotates backward.

[0040] The front wheel 14B is attached to the frame 18 via a front fork 30. A handlebar 34 is coupled to the front fork 30 via a handlebar stem 32. In the present embodiment, the rear wheel 14A is coupled to the crank 12 via the drive mechanism 22. However, at least one of the rear wheel 14A and the front wheel 14B may be coupled to the crank 12 via the drive mechanism 22.

[0041] The human-powered vehicle 10 includes a battery 36 for a human-powered vehicle. The battery 36 includes one or more battery elements. The battery elements include a rechargeable battery (secondary battery). The battery 36 supplies electrical power to a motor 42 of the assist system 40. Preferably, the battery 36 is connected to a controller of the motor 42 such that it performs wireless communication with the controller. The battery 36 is configured to communicate with the controller of the motor 42, for example, through power line communication (PLC).

[0042] The assist system 40 includes the transmission 50 and the motor 42 that assists human driving force. The motor 42 applies driving force to the human-powered vehicle 10. The motor 42 includes one or more electric motors. The motor 42 is configured to transmit rotation to at least one of the front wheel 14B and a human-powered transmission path extending from the pedals 20 to the rear wheel 14A. The human-powered transmission path extending from the pedals 20 to the rear wheel 14A includes the rear wheel 14A. In the present embodiment, the motor 42 is provided on the frame 18 of the human-powered vehicle 10 and configured to transmit rotation to the first rotating body 24. A drive unit is configured to include the motor 42 and a housing on which the motor 42 is provided.A one-way clutch is preferably provided on the power transmission path between the motor 42 and the crankshaft 12A so that, when the crankshaft 12A is rotated in a direction in which the human-powered vehicle 10 moves forward, the motor 42 is not rotated by the rotational force of the crank 12. In a case where the motor 42 is provided on at least one of the rear wheel 14A and the front wheel 14B, the motor 42 may comprise a hub motor.

[0043] Preferably, the assistance system 40 further includes an operating unit 44 that is manually operated to operate the transmission 50. The transmission 50 changes a gear ratio of the human-powered vehicle 10 according to an operation performed on the operating unit 44. The gear ratio is a ratio of the rotational speed of the rear wheel 14A to the rotational speed of the crank 12 (of the first rotating body 24). The operating unit 44 is provided, for example, on the handlebar 34. Preferably, the operating unit 44 is connected to the transmission 50 by a Bowden cable. As an inner cable of the Bowden cable is moved by the operation of the operating unit 44, the transmission 50 is operated to change the gear ratio. The transmission 50 may include a motor configured to change the gear ratio.In this case, the actuating unit 44 and the motor of the transmission 50 are designed to communicate with each other via wired or wireless means.

[0044] As in Fig.3, the transmission 50 includes a first gear unit 52, a second gear unit 54, and a switching unit 56 that changes the gear ratio of the human-powered vehicle 10 in steps. The first gear unit 52 includes a first gear path L1 that changes a speed of input rotation. The second gear unit 54 includes a second gear path L2 that changes a speed of input rotation and is configured to transmit rotation to the first gear unit 52. The transmission 50 further includes an axle shaft member 58. The axle shaft member 58 is a hub axle supported by the frame 18. The first gear unit 52 and the second gear unit 54 are provided on the axle shaft member 58 so as to be adjacent to each other in an axial direction of the axle shaft member 58.

[0045] The first gear unit 52 comprises a first planetary gear unit 60. Preferably, the first planetary gear unit 60 comprises at least two first sun gears 62, at least one first ring gear 64, at least two first planet gears 66, and a first carrier 68. The at least two first planet gears 66 are each in mesh with the at least two first sun gears 62. The first carrier 68 movably supports the at least two first planet gears 66 around the corresponding first sun gears 62. In the present embodiment, the first planetary gear unit 60 comprises two first sun gears 62, a first ring gear 64, and two first planet gears 66. The first sun gears 62 comprise a first sun gear 62A and a first sun gear 62B. The two first planet gears 66 comprise a first planet gear 66A that is in mesh with the first sun gear 62A, and a first planet gear 66B that is in mesh with the first sun gear 62B.

[0046] The first planetary gear 66A and the first planetary gear 66B are integrally formed to form a stepped first planetary gear body 66C. Preferably, the first planetary gear unit 60 comprises a plurality of first planetary gear bodies 66C. The first planetary gear unit 60 comprises, for example, four first planetary gear bodies 66C. The first carrier 68 comprises first parts 68A, each extending through the first planetary gear bodies 66C, a second part 68B, which integrally supports the first parts 68A on one side of the first planetary gear bodies 66C in the axial direction, and a third part 68C, which integrally supports the first parts 68A on the other side of the first planetary gear bodies 66C in the axial direction. The first parts 68A support the first planetary gear bodies 66C and are rotatable relative to the first planetary gear bodies 66C. The first parts 68A may be rotatable relative to the second part 68B and the third part 68C.

[0047] The number of teeth on the first sun gear 62A is smaller than the number of teeth on the first sun gear 62B. The number of teeth on the first planetary gear 66A is larger than the number of teeth on the first planetary gear 66B. The gear ratio in a case where rotation input to the first planetary gear unit 60 is output through the first sun gear 62A is smaller than the gear ratio in a case where rotation input to the first planetary gear unit 60 is output through the first sun gear 62B. Preferably, the at least two first sun gears 62 are provided such that a first sun gear 62 located closer to the second gear unit 54 has a larger number of teeth than a first sun gear 62 located farther away from the second gear unit 54 in the axial direction of the axle shaft member 58.In the present embodiment, the first sun gear 62A is located farther away from the second gear unit 54 in the axial direction of the axle shaft member 58 than the first sun gear 62B.

[0048] Preferably, the second gear unit 54 comprises a second planetary gear unit 70. The second planetary gear unit 70 comprises at least one second sun gear 72, at least one second ring gear 74, at least one second planet gear 76, and a second carrier 78. The at least one second planet gear 76 meshes with the at least one second sun gear 72. The second carrier 78 movably supports the second planet gear 76 around the at least one second sun gear 72. In the present embodiment, the second planetary gear unit 70 comprises a second sun gear 72, a second ring gear 74, and a second planet gear 76.

[0049] The second planetary gear 76 is provided on a second planetary gear body 76A. Preferably, the second planetary gear unit 70 comprises a plurality of second planetary gear bodies 76A. The second planetary gear unit 70 comprises, for example, four second planetary gear bodies 76A. The second carrier 78 comprises first parts 78A extending through the second planetary gear bodies 76A, a second part 78B integrally supporting the first parts 78A on one side of the second planetary gear body 76A in the axial direction, and a third part 78C integrally supporting the first parts 78A on the other side of the second planetary gear body 76A in the axial direction. The first parts 78A support the second planetary gear bodies 76A and are rotatable relative to the second planetary gear bodies 76A. The first parts 78A can be rotatable relative to the second part 78B and the third part 78C.

[0050] The number of teeth on the second sun gear 72 is equal to the number of teeth on the first sun gear 62B. The number of teeth on the second ring gear 74 is equal to the number of teeth on the first ring gear 64. The number of teeth on the second sun gear 72 may be greater than the number of teeth on the first sun gear 62B, or may be less than the number of teeth on the first sun gear 62B. The number of teeth on the second sun gear 72 may be equal to the number of teeth on the first sun gear 62A, may be greater than the number of teeth on the first sun gear 62A, or may be less than the number of teeth on the first sun gear 62A. The number of teeth on the at least two first sun gears 62 and the number of teeth on the at least one second sun gear 72 are determined according to desired gear ratios of the transmission 50.

[0051] Preferably, the transmission 50 further comprises a transmission unit 80. The first carrier 68 and the second ring gear 74 are connected by the transmission unit 80. As in Fig. 3, the transmission unit 80 includes one of a recess 80A and a protrusion 80B located at one of an outer peripheral portion of the first carrier 68 and an inner peripheral portion of the second ring gear 74, and the other of the recess 80A and the protrusion 80B located at the other of the outer peripheral portion of the first carrier 68 and the inner peripheral portion of the second ring gear 74. The length in a circumferential direction of the recess 80A is greater than the length in a circumferential direction of the protrusion 80B. The transmission unit 80 is provided between an outer peripheral portion of the second part 68B of the first carrier 68 and the inner peripheral portion of the second ring gear 74.

[0052] Preferably, the transmission 50 further comprises a first one-way clutch 82 (see Fig. 2). The first carrier 68 and the second carrier 78 are connected by the first one-way clutch 82. The first one-way clutch 82 is provided between an inner peripheral portion of the second part 68B of the first carrier 68 and an outer peripheral portion of the third part 78C of the second carrier 78. The first one-way clutch 82 transmits rotation of the second carrier 78 to the first carrier 68 and does not transmit rotation of the first carrier 68 to the second carrier 78.

[0053] Preferably, the transmission 50 further includes an output body 84, a second one-way clutch 86, and a third one-way clutch 88. The first ring gear 64 is connected to the output body 84 via the second one-way clutch 86. The second ring gear 74 is connected to the output body 84 via the third one-way clutch 88.

[0054] The transmission 50 further includes a hub 90 that houses the first gear unit 52, the second gear unit 54, and the switching unit 56. The hub 90 rotates integrally with the output body 84. The output body 84 is provided on an inner peripheral portion of the hub 90. The output body 84 rotates integrally with the hub 90, for example, in a spline engagement or a serration engagement. The output body 84 may be integrally formed with the hub 90. Flanges 92 are provided on an outer peripheral portion of the hub 90 at opposite axial ends of the hub 90. The flanges 92 have holes 92A that engage with spokes of the rear wheel 14A.

[0055] The second one-way clutch 86 is provided between an outer peripheral portion of the first ring gear 64 and an inner peripheral portion of the output body 84. The second one-way clutch 86 transmits rotation of the first ring gear 64 to the output body 84 and does not transmit rotation of the output body 84 to the first ring gear 64.

[0056] The third one-way clutch 88 is provided between an outer peripheral portion of the second ring gear 74 and the inner peripheral portion of the output body 84. The third one-way clutch 88 transmits rotation of the second ring gear 74 to the output body 84 and does not transmit rotation of the output body 84 to the second ring gear 74.

[0057] The transmission 50 further includes an input body 94. The input body 94 is provided on the axle shaft member 58 so as to be rotatable relative to the axle shaft member 58. The input body 94 transmits rotation of the second rotating body 26 to the second gear unit 54. One end of the input body 94 in the axial direction of the axle shaft member 58 is connected to the second rotating body 26. The other end of the input body 94 in the axial direction of the axle shaft member 58 is connected to an outer peripheral portion of the second part 78B of the second carrier 78. Rotation of the input body 94 is output from the second gear unit 54 to the output body 84 or from the second gear unit 54 and the first gear unit 52 to the output body 84.

[0058] The switching unit 56 changes a rotation state of at least one of the first gear unit 52 and the second gear unit 54 to switch a transmission path S of the rotation input to the first gear unit 52 and the second gear unit 54.

[0059] The transmission path S includes a first transmission path S1 that passes through at least the first transmission path L1, a second transmission path S2 that passes through the second transmission path L2 without passing through the first transmission path L1, and a third transmission path S3 that passes through both the first transmission path L1 and the second transmission path L2. The switching unit 56 switches the transmission path S in the order of the first transmission path S1, the second transmission path S2, and the third transmission path S3 to increase the transmission ratio in stages.

[0060] The first transmission path L1 includes a first path L11 and a second path L12. The switching unit 56 is configured to switch the transmission path S from one of the first transmission path L1 including the first path L11 and the first transmission path L1 including the second path L12 to the other, so that the transmission path S passes through the first transmission path L1. The switching unit 56 is configured to switch from one of the first transmission path L1 including the first path L11 and the first transmission path L1 including the second path L12 to the other in at least one of the first transmission path S1 and the third transmission path S3. In each of the first transmission path S1 and the third transmission path S3, the gear ratio in a case where the first transmission path L1 includes the second path L12 is larger than the gear ratio in a case where the first transmission path L1 includes the first path L11.

[0061] The transmission path S further includes a fourth transmission path S4 that transmits the input rotation without changing the speed. The switching unit 56 switches the transmission path S in the order of the fourth transmission path S4, the first transmission path S1, the second transmission path S2, and the third transmission path S3 to increase the transmission ratio in stages. The fourth transmission path S4 does not pass through any of the first transmission path L1 and the second transmission path L2.

[0062] Table 1 shows the transmission path S in each gear stage formed by the transmission 50 of the present embodiment. In the gear stages, the gear ratio is increased in the order of the first gear stage, the second gear stage, the third gear stage, the fourth gear stage, and the fifth gear stage. In the present embodiment, the switching unit 56 is configured to switch from one of the first transmission path L1 including the first path L11 and the first transmission path L1 including the second path L12 to the other of the third transmission path S3.In the present embodiment, the switching unit 56 is configured to switch the transmission path S from one of the first transmission path L1 including the first path L11 and the first transmission path L1 including the second path L12 to the other, so as to switch from one of the fourth gear stage and the fifth gear stage to the other of the fourth gear stage and the fifth gear stage.

[0063] Preferably, the gear ratio of the first gear unit 52 in the first transmission path S1, which corresponds to a gear ratio one step lower than the gear ratio of the second transmission path S2, is smaller than the gear ratio in the second transmission path S2. In the present embodiment, the gear ratio of the first planetary gear unit 60 passing through the first sun gear 62A is smaller than the gear ratio of the second planetary gear unit 70 passing through the second sun gear 72. [Table 1] Gear stage Transmission path S 1. Gear travel L1 2. Gear travel L2 1. Route L11 2. Route L12 1st gear stage 4. Transmission path S4 - - - 2nd gear stage 1. Transmission path S1 Go through - - 3rd gear stage 2. Transmission path S2 - - Go through 4th gear stage 3. Transmission path S3 Go through - Go through 5th gear stage 3. Transmission path S3 - Go through Go through

[0064] The switching unit 56 comprises pawl elements 96, an arm element 98 and preload elements 100. The pawl elements 96 are provided corresponding to the at least two first sun gears 62 and the at least one second sun gear 72.

[0065] The pawl elements 96 are provided on an outer peripheral portion of the axle shaft member 58 so as to be movable relative to the axle shaft member 58. The pawl elements 96 include a first pawl element 96A, a second pawl element 96B, and a third pawl element 96C. The first pawl element 96A is provided between the outer peripheral portion of the axle shaft member 58 and an inner peripheral portion of the first sun gear 62A. The second pawl element 96B is provided between the outer peripheral portion of the axle shaft member 58 and an inner peripheral portion of the first sun gear 62B. The third pawl element 96C is provided between the outer peripheral portion of the axle shaft member 58 and an inner peripheral portion of the second sun gear 72.

[0066] The arm member 98 is provided on the outer peripheral portion of the axle shaft member 58 so as to be rotatable relative to the axle shaft member 58. The arm member 98 includes a base part 98A, a first arm 98B, a second arm 98C, and a third arm 98D. The base part 98A extends in the axial direction of the axle shaft member 58.

[0067] The switching unit 56 includes a first switching section 56A, a second switching section 56B, and a third switching section 56C. The first switching section 56A includes the first pawl member 96A and the first arm 98B. The second switching section 56B includes the second pawl member 96B and the second arm 98C. The third switching section 56C includes the third pawl member 96C and the third arm 98D.

[0068] The biasing members 100 are provided corresponding to the pawl members 96. Each biasing member 100 biases the corresponding pawl member 96 in a direction that increases a protrusion amount of the pawl member 96 from the axle shaft member 58. Each pawl member 96 has a first state in which the protrusion amount of the pawl member 96 from the axle shaft member 58 is small and a second state in which the protrusion amount of the pawl member 96 from the axle shaft member 58 is large. The arm member 98 is configured to rotate about the axle shaft member 58 according to an operation of the actuating unit 44. According to the rotation of the arm member 98 about the axle shaft member 58, the pawl members 96 change from one of the first state and the second state to the other of the first state and the second state.

[0069] The first arm 98B urges the first pawl member 96A toward the axle shaft member 58 to establish the second state. In the first state, the first pawl member 96A does not engage with the recesses 102 provided on the inner peripheral portion of the first sun gear 62A to permit rotation of the first sun gear 62A relative to the axle shaft member 58. In the second state, the first pawl member 96A engages the recesses 102 provided on the inner peripheral portion of the first sun gear 62A to limit rotation of the first sun gear 62A relative to the axle shaft member 58.

[0070] The second arm 98C pushes the second pawl member 96B toward the axle shaft member 58 to establish the second state. In the first state, the second pawl member 96B does not engage with the recesses 102 provided on the inner peripheral portion of the first sun gear 62B to permit rotation of the first sun gear 62B relative to the axle shaft member 58. In the second state, the second pawl member 96B engages with the recesses 102 provided on the inner peripheral portion of the first sun gear 62B to limit rotation of the first sun gear 62B relative to the axle shaft member 58.

[0071] The third arm 98D pushes the third pawl member 96C toward the axle shaft member 58 to form the second state. In the first state, the third pawl member 96C does not engage with recesses 102 provided on the inner peripheral portion of the second sun gear 72 to allow rotation of the second sun gear 72 relative to the axle shaft member 58. In the second state, the third pawl member 96C engages with the recesses 102 provided on the inner peripheral portion of the second sun gear 72 to limit rotation of the second sun gear 72 relative to the axle shaft member 58.

[0072] The first arm 98B, the second arm 98C, and the third arm 98D are configured so that the respective pawl members 96 enter the first state or the second state in a rotation phase R with respect to the axle shaft member 58. In the present embodiment, the rotation phase R of the arm member 98 with respect to the axle shaft member 58 includes a first rotation phase R1, a second rotation phase R2, a third rotation phase R3, a fourth rotation phase R4, and a fifth rotation phase R5. In a case where the rotation phase R is the first rotation phase R1, the transmission 50 forms the first gear stage. In a case where the rotation phase R is the second rotation phase R2, the transmission 50 forms the second gear stage. In a case where the rotation phase R is the third rotation phase R3, the transmission 50 forms the third gear stage. In a case where the rotation phase R is the fourth rotation phase R4, the transmission 50 forms the fourth gear stage.In a case where the rotational phase R is the fifth rotational phase R5, the gear 50 forms the fifth gear stage.

[0073] The switching unit 56 is designed to change rotational states of the at least two first sun gears 62 such that the transmission path S passes through one of the at least two first sun gears 62. The first path L11 passes through one of the at least two first sun gears 62. The second path L12 passes through one of the first sun gears 62 that is different from the one of the at least two first sun gears 62 that the first path L11 passes through. For example, the first path L11 passes through the first sun gear 62A, and the second path L12 passes through the first sun gear 62B. The switching unit 56 sets the first pawl element 96A to the second state and the second pawl element 96B to the first state, so that the transmission path S passes through the first sun gear 62A. The switching unit 56 sets the first pawl element 96A to the first state and the second pawl element 96B to the second state, so that the transmission path S passes through the first sun gear 62B.

[0074] The switching unit 56 is configured to change a rotational state of the at least one second sun gear 72 such that the transmission path S passes through one of the at least one second sun gear 72. The switching unit 56 sets the third pawl element 96C to the second state so that the transmission path S passes through the second sun gear 72.

[0075] The switching unit 56 is configured to change rotational states of the at least two first sun gears 62 after changing a rotational state of the at least one second sun gear 72 to increase the gear ratio in steps and switch the transmission path S from the first transmission path S1 to the second transmission path S2. The second arm 98C is configured to set the third pawl element 96C to the second state between the second rotational phase R2 and the third rotational phase R3, and the first arm 98B is configured to set the first pawl element 96A to the first state in the third rotational phase R3. After limiting the rotation of the second sun gear 72 relative to the axle shaft element 58, the rotation of the first sun gears 62 relative to the axle shaft element 58 is permitted.This limits the formation of a condition that allows rotation of both the second sun gear 72 and the first sun gears 62 relative to the axle shaft member 58. Thus, the gear stage is changed in a preferred manner.

[0076] Table 2 shows rotational states of the first sun gear 62A, the first sun gear 62B, and the second sun gear 72 in each gear stage formed by the arm member 98 of the present embodiment. [Table 2] Gear stage 1. Planetary gear unit 2. Planetary gear unit Rotation of the 1st sun gear 62A Rotation of the 1st sun gear 62B Rotation of the 2nd sun gear 72 1st gear stage Allow Allow Allow 2nd gear stage Limit Allow Allow 3rd gear stage Allow Allow Limit 4th gear stage Limit Allow Limit 5th gear stage Allow Limit Limit

[0077] In the fourth transmission path S4, which is Fig.12, rotation of the second carrier 78 rotates the first carrier 68 with the first one-way clutch 82, and rotation of the first carrier 68 rotates the second ring gear 74 with the transfer unit 80. In the fourth transfer path S4, both the first sun gears 62 and the second sun gear 72 are allowed to rotate relative to the axle shaft member 58. Therefore, rotation input from the input body 94 to the first gear unit 52 is output to the output body 84 via the third one-way clutch 88 without changing the speed.

[0078] In the first transmission path S1, which is Fig. 13, rotation of the second carrier 78 rotates the first carrier 68 with the first one-way clutch 82. In the third transmission path S3, rotation of the second ring gear 74 rotates the first carrier 68 with the transmission unit 80.

[0079] In the first transmission path S1, since the second sun gear 72 is allowed to rotate relative to the axle shaft member 58, rotation input from the input body 94 to the first transmission unit 52 is input to the second transmission unit 54 via the first one-way clutch 82 without changing the speed. The rotation input to the second transmission unit 54 is increased in speed according to the gear ratio corresponding to the number of teeth on the first sun gear 62A, whose rotation is limited, and output to the output body 84 via the second one-way clutch 86. In the first transmission path S1, the second ring gear 74 rotates the first carrier 68 with the transmission unit 80.

[0080] In the second transmission path S2, which is Fig.14, since the rotation of the second sun gear 72 relative to the axle shaft member 58 is limited, the rotation input from the input body 94 to the first gear unit 52 is increased in speed and output to the output body 84 via the third one-way clutch 88. In the second transmission path S2, since all of the first sun gears 62 are allowed to rotate relative to the axle shaft member 58, the rotation of the output body 84 is not transmitted to the first gear unit 52 through the second one-way clutch 86.

[0081] As in Fig. 10, rotates in the first transmission path S1, which is in Fig.13, since the second sun gear 72 is allowed to rotate relative to the axle shaft member 58, rotation of the first carrier 68 drives the second ring gear 74. The speed of the first carrier 68 and the second ring gear 74 is less than the speed of the first ring gear 64 and the output body 84. Thus, the third one-way clutch 88 allows relative rotation of the second ring gear 74 and the output body 84.

[0082] In the Fig.In the state shown in Figure 10, the switching unit 56 changes the second sun gear 72 from a state that allows rotation relative to the axle shaft member 58 to a state that limits rotation relative to the axle shaft member 58, so that the rotational speed of the second ring gear 74 is greater than the rotational speed of the first carrier 68. Thus, the projection 80B moves relatively within the recess 80A, and the second ring gear 74 and the first carrier 68 begin to rotate relative to each other. In this state, the gear ratio of the first gear unit 52 passing through the first sun gear 62A is smaller than the gear ratio of the second gear unit 54 passing through the second sun gear 72. Thus, the rotational speed of the second ring gear 74 becomes greater than the rotational speed of the first ring gear 64.Thus, rotation of the second ring gear 74 rotates the output body 84 with the third one-way clutch 88, and the second one-way clutch 86 allows the first ring gear 64 and the output body 84 to rotate relative to each other. In this state, the switching unit 56 changes from a state that allows rotation of the first sun gear 62A relative to the axle shaft member 58 to a state that allows rotation. Since relative rotation of the first ring gear 64 and the output body 84 is permitted, in a state where the load on the first sun gear 62A is light, the rotational state of the first sun gear 62A is changed in a preferential manner.

[0083] As in Fig. 11, in a case where the projection 80B reaches the opposite end in a rotational direction in the recess 80A, the rotation of the second ring gear 74 rotates the first carrier 68. Thus, in the second transmission path S2 shown in Fig.14, rotation of the second carrier 78 is not transmitted to the first carrier 68 through the first one-way clutch 82.

[0084] In the third transmission path S3, which is Fig. As shown in Fig. 15, since the rotation of the second sun gear 72 is limited relative to the axle shaft member 58, the rotation input from the input body 94 to the first gear unit 52 is increased in speed and input to the second gear unit 54 via the transfer unit 80. The rotation input to the second gear unit 54 is increased in speed according to the gear ratio corresponding to the number of teeth on the first sun gear 62A whose rotation is limited, and output to the output body 84 via the second one-way clutch 86.

[0085] In the third transmission path S3, which is Fig.16, since the rotation of the second sun gear 72 is limited relative to the axle shaft member 58, the rotation input from the input body 94 to the first gear unit 52 is increased in speed and input to the second gear unit 54 via the transfer unit 80. The rotation input to the second gear unit 54 is increased in speed according to the gear ratio corresponding to the number of teeth on the first sun gear 62B whose rotation is limited, and output to the output body 84 via the second one-way clutch 86. Second embodiment

[0086] With reference to the Fig.17 to 25, a second embodiment of a transmission 50A will now be described. The transmission 50A of the second embodiment differs from the transmission 50 of the first embodiment in a structure that includes eight gear stages, but otherwise has the same design as the transmission 50 of the first embodiment. The same reference numerals are assigned to the components that are the same as the corresponding components of the first embodiment.

[0087] As in Fig.As shown in Figure 18, the transmission 50A includes a first transmission unit 52A, a second transmission unit 54, and a switching unit 56 that changes the gear ratio of the human-powered vehicle 10 in steps. The first transmission unit 52A includes a first transmission path L1 that changes a speed of input rotation. The second transmission unit 54 includes a second transmission path L2 that changes a speed of input rotation and is configured to transmit rotation to the first transmission unit 52A.

[0088] The first gear unit 52A includes a first planetary gear unit 60A. Preferably, the first planetary gear unit 60A includes at least two first sun gears 62, at least one first ring gear 64, at least two first planet gears 66, and a first carrier 68. The at least two first planet gears 66 are each in mesh with the at least two first sun gears 62. The first carrier 68 movably supports the at least two first planet gears 66 around the corresponding first sun gears 62. In the present embodiment, the first planetary gear unit 60A includes at least three first sun gears 62. In the present embodiment, the first planetary gear unit 60A includes three first sun gears 62, a first ring gear 64, and three first planet gears 66. The first sun gears 62 include a first sun gear 62A, a first sun gear 62B, and a first sun gear 62C.The three first planetary gears 66 include a first planetary gear 66A meshing with the first sun gear 62A, a first planetary gear 66B meshing with the first sun gear 62B, and a first planetary gear 66D meshing with the first sun gear 62C.

[0089] The first planetary gear 66A, the first planetary gear 66B, and the first planetary gear 66D are integrally formed to form a stepped first planetary gear body 66E. Preferably, the first planetary gear unit 60A comprises a plurality of first planetary gear bodies 66E. The first planetary gear unit 60A comprises, for example, four first planetary gear bodies 66E. The first carrier 68 comprises first parts 68A, each extending through the first planetary gear bodies 66E, a second part 68B, which integrally supports the first parts 68A on one side of the first planetary gear bodies 66E in the axial direction, and a second part 68B, which integrally supports the first parts 68A on the other side of the first planetary gear bodies 66E in the axial direction. The first parts 78A support the first planetary gear bodies 66E and are rotatable relative to the first planetary gear bodies 66E. The first parts 68A may be rotatable relative to the second part 68B and the third part 68C.

[0090] The number of teeth on the first sun gear 62B is smaller than the number of teeth on the first sun gear 62C. The number of teeth on the first planetary gear 66B is larger than the number of teeth on the first planetary gear 66D. The gear ratio in a case where rotation input to the first planetary gear unit 60A is output through the first sun gear 62B is smaller than the gear ratio in a case where rotation input to the first planetary gear unit 60A is output through the first sun gear 62C. Preferably, the at least three first sun gears 62 are provided such that a first sun gear 62 located closer to the second gear unit 54 has a larger number of teeth than a first sun gear 62 located farther away from the second gear unit 54 in the axial direction of the axle shaft member 58.In the present embodiment, the first sun gear 62B is located farther away from the second gear unit 54 in the axial direction of the axle shaft member 58 than the first sun gear 62C.

[0091] In the present embodiment, preferably, the number of teeth on the second sun gear 72 is greater than the number of teeth on the first sun gear 62C, and the number of teeth on the second ring gear 74 is equal to the number of teeth on the first ring gear 64. The number of teeth on the second sun gear 72 may be less than the number of teeth on the first sun gear 62C, or may be equal to the number of teeth on the first sun gear 62C. The number of teeth on the second sun gear 72 may be equal to the number of teeth on the first sun gear 62A, may be greater than the number of teeth on the first sun gear 62A, or may be less than the number of teeth on the first sun gear 62A. The number of teeth on the second sun gear 72 may be equal to the number of teeth on the first sun gear 62B, may be greater than the number of teeth on the first sun gear 62B, or may be less than the number of teeth on the first sun gear 62B.The number of teeth on the at least three first sun gears 62 and the number of teeth on the at least one second sun gear 72 are determined according to desired gear ratios of the transmission 50A.

[0092] Preferably, the transmission 50A further includes a transfer unit 80, a first one-way clutch 82, an output body 84, a second one-way clutch 86, and a third one-way clutch 88. The transmission 50A preferably further includes a hub 90 that houses the first gear unit 52A, the second gear unit 54, and the shift unit 56. The transmission 50A preferably further includes an input body 94. Rotation of the input body 94 is output from the second gear unit 54 to the output body 84 or from the second gear unit 54 and the first gear unit 52A to the output body 84.

[0093] The switching unit 56 changes a rotational state of at least one of the first gear unit 52A and the second gear unit 54 to switch the transmission path S of the rotation input to the first gear unit 52A and the second gear unit 54A from one transmission path S to another transmission path S.

[0094] In the present embodiment, the first transmission path L1 further includes a third path L13. The switching unit 56 is configured to switch from one of the first transmission path L1 including the second path L12 and the first transmission path L1 including the third path L13 to the other in at least one of the first transmission path S1 and the third transmission path S3. In each of the first transmission path S1 and the third transmission path S3, the gear ratio in a case where the first transmission path L1 includes the third path L13 is larger than the gear ratio in a case where the first transmission path L1 includes the second path L12. The third path L13 passes through a first sun gear 62 that is different from those of the at least three first sun gears 62 that the first path L11 and the second path L12 pass through. In the present embodiment, the third path L13 passes through the first sun gear 62C.

[0095] Table 3 shows the transmission path S in each gear stage formed by the transmission 50A of the present embodiment. In gear stages, the gear ratio is increased in the order of first gear stage, second gear stage, third gear stage, fourth gear stage, fifth gear stage, sixth gear stage, seventh gear stage, and eighth gear stage.

[0096] In the present embodiment, the switching unit 56 is configured to switch from one of the first transmission path L1 including the first path L11 and the first transmission path L1 including the second path L12 to the other in the first transmission path S1 and the third transmission path S3. In the present embodiment, the switching unit 56 is configured to switch the transmission path S from one of the first transmission path L1 including the first path L11 and the first transmission path L1 including the second path L12 to the other, so as to switch from one of the second gear stage and the third gear stage to the other of the second gear stage and the third gear stage.In the present embodiment, the switching unit 56 is configured to switch the transmission path S from one of the first transmission path L1 including the first path L11 and the first transmission path L1 including the second path L12 to the other, so as to switch from one of the sixth gear stage and the seventh gear stage to the other of the sixth gear stage and the seventh gear stage.

[0097] In the present embodiment, the switching unit 56 is configured to switch from one of the first transmission path L1 including the second path L12 and the first transmission path L1 including the third path L13 to the other in the first transmission path S1 and the third transmission path S3. In the present embodiment, the switching unit 56 is configured to switch the transmission path S from one of the first transmission path L1 including the second path L12 and the first transmission path L1 including the third path L13 to the other, so as to switch from one of the third gear stage and the fourth gear stage to the other of the third gear stage and the fourth gear stage.In the present embodiment, the switching unit 56 is configured to switch the transmission path S from one of the first transmission path L1 including the second path L12 and the first transmission path L1 including the third path L13 to the other, so as to switch from one of the seventh gear stage and the eighth gear stage to the other of the seventh gear stage and the eighth gear stage.

[0098] Preferably, the gear ratio of the first gear unit 52 in the first transmission path S1, which corresponds to a gear ratio one step lower than the gear ratio of the second transmission path S2, is smaller than the gear ratio in the second transmission path S2. In the present embodiment, the gear ratio of the first planetary gear unit 60 passing through the first sun gear 62C is smaller than the gear ratio of the second planetary gear unit 70 passing through the second sun gear 72. [Table 3] Gear stage Transmission path S 1. Gear travel L1 2. Gear travel L2 1. Route L11 2. Route L12 3. Route L13 1st gear stage 4. Transmission path S4 - - - - 2nd gear stage 1. Transmission path S1 Go through - - - 3rd gear stage 1. Transmission path S1 - Go through - - 4th gear stage 1. Transmission path S1 - - Go through - 5th gear stage 2. Transmission path S2 - - - Go through 6th gear stage 3. Transmission path S3 Go through - - Go through 7th gear stage 3. Transmission path S3 - Go through - Go through 8th gear stage 3. Transmission path S3 - - Go through Go through

[0099] The first transmission path L1 includes a plurality of paths having different gear ratios. The switching unit 56 is configured to switch the transmission path from one of the first transmission path L1, which includes one of the plurality of paths, and the first transmission path L1, which includes another of the plurality of paths, to the other, so that the transmission path S passes through the first transmission path L1.In a case where the gear ratio is increased in stages, between a gear stage formed by a transmission path S passing through the first transmission path L1, which includes one of the plurality of paths that receives a first gear ratio, and a gear stage formed by a transmission path S passing through the first transmission path L1, which includes another of the plurality of paths that receives a smaller gear ratio than the first gear ratio, the switching unit 56 includes a gear stage formed by a transmission path S that does not pass through the first transmission path L1. Preferably, one of the plurality of paths that receives the first gear ratio corresponds to one of the plurality of paths that is configured to receive the largest gear ratio.Preferably, one of the plurality of paths that receives a smaller gear ratio than the first gear ratio corresponds to one of the plurality of paths configured to receive the smallest gear ratio. In the present embodiment, the one of the plurality of paths that receives the first gear ratio corresponds to the third path L13; the one of the plurality of paths that receives a smaller gear ratio than the first gear ratio corresponds to the first path L11. In the present embodiment, the gear stage formed by the transmission path S passing through the first transmission path L1, which includes one of the plurality of paths that receives the first gear ratio, corresponds to the fourth gear stage.The gear stage formed by the transmission path S passing through the first transmission path L1, which has a lower gear ratio than the first gear ratio, corresponds to the sixth gear stage. The gear stage formed by the transmission path S not passing through the first transmission path L1 corresponds to the fifth gear stage.

[0100] The switching unit 56 includes pawl elements 96, an arm element 104, and biasing elements 100. The pawl elements 96 further include a fourth pawl element provided between the outer peripheral portion of the axle shaft element 58 and an inner peripheral portion of the first sun gear 62A.

[0101] The arm element 104, which in Fig.17, is provided on the outer peripheral portion of the axle shaft member 58 so as to be rotatable relative to the axle shaft member 58. The arm member 104 includes a base part 104A, a first arm 104B, a second arm 104C, a third arm 104D, and a fourth arm 104E. The base part 104A extends in the axial direction of the axle shaft member 58.

[0102] The switching unit 56 includes a first switching section 56A, a second switching section 56B, and a third switching section 56C. The first switching section 56A includes the first pawl element 96A and the first arm 104B. The second switching section 56B includes the second pawl element 96B and the second arm 104C. The third switching section 56C includes the third pawl element 96C and the third arm 104D. A fourth switching unit 56D includes the fourth pawl element and the fourth arm 104E.

[0103] The first arm 104B urges the first pawl member 96A toward the axle shaft member 58 to establish the second state. In the first state, the first pawl member 96A does not engage with the recesses 102 provided on the inner peripheral portion of the first sun gear 62A to permit rotation of the first sun gear 62A relative to the axle shaft member 58. In the second state, the first pawl member 96A engages with the recesses 102 provided on the inner peripheral portion of the first sun gear 62A to limit rotation of the first sun gear 62A relative to the axle shaft member 58.

[0104] The second arm 104C urges the second pawl member 96B toward the axle shaft member 58 to establish the second state. In the first state, the second pawl member 96B does not engage the recesses 102 provided on the inner peripheral portion of the first sun gear 62B to permit rotation of the first sun gear 62B relative to the axle shaft member 58. In the second state, the second pawl member 96B engages the recesses 102 provided on the inner peripheral portion of the first sun gear 62B to limit rotation of the first sun gear 62B relative to the axle shaft member 58.

[0105] The third arm 104D pushes the third pawl member 96C toward the axle shaft member 58 to form the second state. In the first state, the third pawl member 96C does not engage with recesses 102 provided on the inner peripheral portion of the second sun gear 72 to allow rotation of the second sun gear 72 relative to the axle shaft member 58. In the second state, the third pawl member 96C engages with the recesses 102 provided on the inner peripheral portion of the second sun gear 72 to limit rotation of the second sun gear 72 relative to the axle shaft member 58.

[0106] The fourth arm 104E pushes the fourth pawl member toward the axle shaft member 58 to form the second state. In the first state, the fourth pawl member does not engage the recesses 102 provided on the inner peripheral portion of the first sun gear 62C to allow rotation of the first sun gear 62C relative to the axle shaft member 58. In the second state, the fourth pawl member engages the recesses 102 provided on the inner peripheral portion of the first sun gear 62C to limit rotation of the first sun gear 62C relative to the axle shaft member 58.

[0107] The first arm 104B, the second arm 104C, the third arm 104D, and the fourth arm 104E are configured so that the respective pawl members 96 enter the first state or the second state in a rotation phase Q with respect to the axle shaft member 58. In the present embodiment, the rotation phase Q of the arm member 104 with respect to the axle shaft member 58 includes the first rotation phase Q1, the second rotation phase Q2, the third rotation phase Q3, the fourth rotation phase Q4, the fifth rotation phase Q5, the sixth rotation phase Q6, the seventh rotation phase Q7, and the eighth rotation phase Q8. In a case where the rotation phase Q is the first rotation phase Q1, the transmission 50A forms the first gear stage. In a case where the rotation phase Q is the second rotation phase Q2, the transmission 50A forms the second gear stage. In a case where the rotation phase Q is the third rotation phase Q3, the gear 50A forms the third gear stage.In a case where the rotation phase Q is the fourth rotation phase Q4, the gear 50A forms the fourth gear stage. In a case where the rotation phase Q is the fifth rotation phase Q5, the gear 50A forms the fifth gear stage. In a case where the rotation phase Q is the sixth rotation phase Q6, the gear 50A forms the sixth gear stage. In a case where the rotation phase Q is the seventh rotation phase Q7, the gear 50A forms the seventh gear stage. In a case where the rotation phase Q is the eighth rotation phase Q8, the gear 50A forms the eighth gear stage.

[0108] The switching unit 56 is configured to change a rotational state of the first sun gears 62 such that the transmission path S passes through one of the at least two first sun gears 62. The first path L11 passes through one of the at least two first sun gears 62. The second path L12 passes through one of the first sun gears 62 that is different from the one of the at least two first sun gears 62 that the first path L11 passes through. For example, the first path L11 passes through the first sun gear 62A, the second path L12 passes through the first sun gear 62B, and the third path L13 passes through the first sun gear 62C. The switching unit 56 sets the first pawl element 96A to the second state, the second pawl element 96B to the first state, and the fourth pawl element to the first state, so that the transmission path S passes through the first sun gear 62A.The switching unit 56 sets the first pawl element 96A to the first state, the second pawl element 96B to the second state, and the fourth pawl element to the first state, so that the transmission path S passes through the first sun gear 62B. The switching unit 56 sets the first pawl element 96A to the first state, the second pawl element 96B to the first state, and the fourth pawl element to the second state, so that the transmission path S passes through the first sun gear 62C.

[0109] The switching unit 56 is configured to change the rotational states of the at least two first sun gears 62 after changing the rotational state of the at least one second sun gear 72, in order to increase the gear ratio in steps and switch the transmission path S from the first transmission path S1 to the second transmission path S2. The second arm 104C is configured to set the fourth pawl element 96A to the second state between the fourth rotational phase Q4 and the fifth rotational phase Q5. The first arm 104B is configured to set the first pawl element 96A to the first state in the fifth rotational phase R5.

[0110] Table 4 shows rotational states of the first sun gear 62A, the first sun gear 62B, the first sun gear 62C, and the second sun gear 72 in each gear stage formed by the arm member 104 of the present embodiment. [Table 4] 1. Planetary gear unit 2. Planetary gear unit Gear stage Rotation of the 1st sun gear 62A Rotation of the 1st sun gear 62B Rotation of the 1st sun gear 62C Rotation of the 1st sun gear 72 1st gear stage Allow Allow Allow Allow 2nd gear stage Limit Allow Allow Allow 3rd gear stage Allow Limit Allow Allow 4th gear stage Allow Allow Limit Allow 5th gear stage Allow Allow Allow Limit 6th gear stage Limit Allow Allow Limit 7th gear stage Allow Limit Allow Limit 8th gear stage Allow Allow Limit Limit

[0111] In the fourth transmission path S4, which is Fig. 18, rotation of the second carrier 78 rotates the first carrier 68 with the first one-way clutch 82, and rotation of the first carrier 68 rotates the second ring gear 74 with the transfer unit 80. In the fourth transfer path S4, both the first sun gears 62 and the second sun gear 72 are allowed to rotate relative to the axle shaft member 58. Therefore, rotation input from the input body 94 to the first gear unit 52 is output to the output body 84 via the third one-way clutch 88 without changing the speed.

[0112] In the first transmission paths S1, which are in the Fig. 19, Fig. 20 and Fig. 21, rotation of the second carrier 78 rotates the first carrier 68 with the first one-way clutch 82. In the third transmission path S3, rotation of the second ring gear 74 rotates the first carrier 68 with the transmission unit 80.

[0113] In the first transmission paths S1, since the second sun gear 72 is allowed to rotate relative to the axle shaft member 58, rotation input from the input body 94 to the first transmission unit 52 is input to the second transmission unit 54 via the first one-way clutch 82 without changing the speed.

[0114] In the first transmission path S1, which is Fig. As shown in Figure 19, the rotation input to the second gear unit 54 is increased according to the gear ratio corresponding to the number of teeth on the first sun gear 62A, whose rotation is limited, and output to the output body 84 via the second one-way clutch 86. In the first transmission path S1, the second ring gear 74 rotates the first carrier 68 with the transmission unit 80.

[0115] In the first transmission path S1, which is Fig. As shown in Figure 20, the rotation input to the second gear unit 54 is increased according to the gear ratio corresponding to the number of teeth on the first sun gear 62B, whose rotation is limited, and output to the output body 84 via the second one-way clutch 86. In the first transmission path S1, the second ring gear 74 rotates the first carrier 68 with the transmission unit 80.

[0116] In the first transmission path S1, which is Fig. As shown in Figure 21, the rotation input to the second gear unit 54 is increased according to the gear ratio corresponding to the number of teeth on the first sun gear 62C, whose rotation is limited, and output to the output body 84 via the second one-way clutch 86. In the first transmission path S1, the second ring gear 74 rotates the first carrier 68 with the transmission unit 80.

[0117] In the second transmission path S2, which is Fig. 22, since the rotation of the second sun gear 72 relative to the axle shaft member 58 is limited, the rotation input from the input body 94 to the first gear unit 52 is increased in speed and output to the output body 84 via the third one-way clutch 88. In the second transmission path S2, since all of the first sun gears 62 are allowed to rotate relative to the axle shaft member 58, the rotation of the output body 84 is not transmitted to the first gear unit 52 through the second one-way clutch 86.

[0118] As in Fig. 21, rotates in the first transmission path S1, which is in Fig. 21, since the second sun gear 72 is allowed to rotate relative to the axle shaft member 58, rotation of the first carrier 68 drives the second ring gear 74. The speed of the first carrier 68 and the second ring gear 74 is less than the speed of the first ring gear 64 and the output body 84. Thus, the third one-way clutch 88 allows relative rotation of the second ring gear 74 and the output body 84.

[0119] In the Fig. In the state shown in Figure 10, the switching unit 56 changes the second sun gear 72 from a state that allows rotation relative to the axle shaft member 58 to a state that limits rotation relative to the axle shaft member 58, so that the rotational speed of the second ring gear 74 is greater than the rotational speed of the first carrier 68. Thus, the projection 80B moves relatively within the recess 80A, and the second ring gear 74 and the first carrier 68 begin to rotate relative to each other. In this state, the gear ratio of the first gear unit 52 passing through the first sun gear 62C is smaller than the gear ratio of the second gear unit 54 passing through the second sun gear 72. Thus, the rotational speed of the second ring gear 74 becomes greater than the rotational speed of the first ring gear 64.Thus, rotation of the second ring gear 74 rotates the output body 84 with the third one-way clutch 88, and the second one-way clutch 86 allows the first ring gear 64 and the output body 84 to rotate relative to each other. In this state, the switching unit 56 changes from a state that limits rotation of the first sun gear 62C relative to the axle shaft member 58 to a state that allows rotation. Since relative rotation of the first ring gear 64 and the output body 84 is permitted, in a state where the load on the first sun gear 62A is light, the rotational state of the first sun gear 62C is changed in a preferential manner.

[0120] As in Fig. 11, in a case where the projection 80B reaches the opposite end in a rotational direction in the recess 80A, the rotation of the second ring gear 74 rotates the first carrier 68. Thus, in the second transmission path S2 shown in Fig. 22, rotation of the second carrier 78 is not transmitted to the first carrier 68 through the first one-way clutch 82.

[0121] In the third transmission path S3, which is Fig. 23, since the rotation of the second sun gear 72 is limited relative to the axle shaft member 58, the rotation input from the input body 94 to the first gear unit 52 is increased in speed and input to the second gear unit 54 via the transfer unit 80. The rotation input to the second gear unit 54 is increased in speed according to the gear ratio corresponding to the number of teeth on the first sun gear 62A whose rotation is limited, and output to the output body 84 via the second one-way clutch 86.

[0122] In the third transmission path S3, which is Fig. 24, since the rotation of the second sun gear 72 is limited relative to the axle shaft member 58, the rotation input from the input body 94 to the first gear unit 52 is increased in speed and input to the second gear unit 54 via the transfer unit 80. The rotation input to the second gear unit 54 is increased in speed according to the gear ratio corresponding to the number of teeth on the first sun gear 62B whose rotation is limited, and output to the output body 84 via the second one-way clutch 86.

[0123] In the third transmission path S3, which is Fig.25, since the rotation of the second sun gear 72 is limited relative to the axle shaft member 58, the rotation input from the input body 94 to the first gear unit 52 is increased in speed and input to the second gear unit 54 via the transfer unit 80. The rotation input to the second gear unit 54 is increased in speed according to the gear ratio corresponding to the number of teeth on the first sun gear 62C whose rotation is limited, and output to the output body 84 via the second one-way clutch 86. Modified examples

[0124] The description relating to the above embodiments exemplifies applicable forms of a transmission for a human-powered vehicle and a human-powered vehicle assist system including the transmission according to the present invention, without any intention of limitation. The transmission for a human-powered vehicle and the human-powered vehicle assist system including the transmission according to the present invention can be applied, for example, to modified examples of the embodiments described below and to combinations of at least two of the modified examples that do not contradict each other. In the modified examples described hereinafter, the same reference numerals are given to the components that are the same as the corresponding components of the above embodiment.Such components are not described in detail.

[0125] The first sun gears 62 may include four or more first sun gears 62. In this case, the switching unit 56 is provided for each of the first sun gears 62.

[0126] The second transmission unit 54 may include a transmission device other than a planetary gear mechanism instead of or in addition to the second planetary gear unit 70. The second transmission unit 54 includes, for example, a manual transmission and a continuously variable transmission device.

[0127] The second planetary gear unit 70 may include two or more sun gears 72. In this case, it is preferred that the switching unit 56 be configured to limit the rotation of none or one of the second sun gears 72 included in the second planetary gear unit 70 relative to the axle shaft member 58 in each gear stage.

[0128] The transmission 50 may be configured to change the speed of rotation introduced into the crankshaft 12A and transmit the rotation to the first rotating body 24. In this case, the transmission 50 may be provided on the crankshaft 12A.

[0129] The transmissions 50 and 50A may be used for a human-powered vehicle 10 that does not include the engine 42.

[0130] Throughout this specification, the phrase "at least one of" as used in this invention means "one or more" of a desired selection. In one example, the phrase "at least one of" as used in this invention means "only a single selection" or "both of two selections" when the number of selections is two. In another example, the phrase "at least one of" as used in this invention means "only a single selection" or "any combination of two or more selections" when the number of selections is three or more. Description of reference symbols 10 Human-powered vehicle 40 Support system 42 engine 44 Actuating unit 50, 50A gearbox 52, 52A First gear unit 60, 60A First planetary gear unit 62, 62A, 62B, 62C First sun gear 64 First ring gear 66, 66A, 66B, 66D First planetary gear 68 First Carrier 54 Second gear unit 70 Second planetary gear unit 72 Second sun gear 74 Second ring gear 76 Second planetary gear 78 Second carrier 56 switching unit 80 transmission unit 80A recess 80B lead 82 First freewheel clutch 84 starting bodies 86 Second freewheel clutch 88 Third freewheel clutch 90 hub QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 4564978

[0003]

Claims

[1] Transmission for a human-powered vehicle, the transmission comprising: a first gear unit including a first gear path that changes a speed of rotation that is initiated; a second gear unit comprising a second gear path that changes a speed of rotation that is initiated, the second gear unit being configured to transmit rotation to the first gear unit; and a switching unit that changes a gear ratio of the human-powered vehicle in stages, whereby the first gear unit comprises a first planetary gear unit, the switching unit changes a rotational state of at least one of the first gear unit and the second gear unit to switch a transmission path of the rotation input to the first gear unit and the second gear unit, the transmission path comprises a first transmission path passing through at least the first transmission path, a second transmission path passing through the second transmission path without passing through the first transmission path, and a third transmission path passing through both the first transmission path and the second transmission path; and the switching unit switches the transmission path in the order of first transmission path, second transmission path and third transmission path in order to increase the transmission ratio in steps. [2] Transmission according to claim 1, wherein the first transmission path comprises a first path and a second path; the switching unit is configured to switch from one of the first transmission path including the first path and the first transmission path including the second path to the other of the first transmission path including the first path and the first transmission path including the second path in at least one of the first transmission path and the third transmission path; and the gear ratio in a case where the first transmission path includes the second path is larger in each of the first transmission path and the third transmission path than that in a case where the first transmission path includes the first path. [3] Transmission according to claim 2, wherein the first planetary gear unit comprises at least two first sun gears, at least one first ring gear, at least two first planet gears each meshing with the at least two first sun gears, and a first carrier movably supporting the at least two first planet gears around the corresponding first sun gears; and the switching unit is designed to change a rotational state of the at least two first sun gears such that the transmission path passes through one of the at least two first sun gears; the first path passes through one of the at least two first sun gears; and the second path passes through the first sun gear which is different from the one of the at least two first sun gears through which the first path passes. [4] Transmission according to claim 2, wherein the first transmission path further comprises a third path, the switching unit is configured to switch from one of the first transmission path including the second path and the first transmission path including the third path to the other of the first transmission path including the second path and the first transmission path including the third path in at least one of the first transmission path and the third transmission path, and the gear ratio in a case where the first transmission path includes the third path is larger in each of the first transmission path and the third transmission path than that in a case where the first transmission path includes the second path. [5] Transmission according to claim 3, wherein the first transmission path further comprises a third path, the switching unit is configured to switch from one of the first transmission path including the second path and the first transmission path including the third path to the other of the first transmission path including the second path and the first transmission path including the third path in at least one of the first transmission path and the third transmission path, the gear ratio in a case where the first transmission path includes the third path is larger in each of the first transmission path and the third transmission path than that in a case where the first transmission path includes the second path, the first planetary gear unit comprises at least three first sun gears, and the third path passes through a first sun gear which is different from those of the at least three first sun gears passed through by the first path and the second path. [6] Transmission according to one of claims 1 to 5, wherein the transmission path further comprises a fourth transmission path that transmits rotation that is introduced without changing the speed, and the switching unit switches the transmission path in the order of fourth transmission path, first transmission path, second transmission path and third transmission path to increase the transmission ratio in steps. [7] Transmission according to claim 3 or 5, wherein the second gear unit comprises a second planetary gear unit; the second planetary gear unit comprises at least one second sun gear, at least one second ring gear, at least one second planetary gear meshing with the at least one second sun gear, and a second carrier movably supporting the second planetary gear around the at least one second sun gear; the switching unit is designed to change a rotational state of the at least one second sun gear such that the transmission path passes through one of the at least one second sun gear; the first carrier and the second ring gear are connected by a transmission unit; the first carrier and the second carrier are connected by a first one-way clutch; a rotation of the second carrier rotates the first carrier with the first one-way clutch in the first transmission path; and a rotation of the second ring gear rotates the first carrier with the transmission unit in the third transmission path. [8] Transmission according to claim 7, wherein the transmission path further comprises a fourth transmission path that transmits rotation that is introduced without changing the speed, and a rotation of the second carrier rotates the first carrier with the first one-way clutch and a rotation of the first carrier rotates the second ring gear with the transmission unit in the fourth transmission path. [9] The transmission according to claim 7, wherein the switching unit is configured to change a rotational state of the at least two first sun gears after changing a rotational state of the at least one second sun gear to increase the gear ratio in steps and switch the transmission path from the first transmission path to the second transmission path. [10] Transmission according to claim 9, wherein the transmission unit includes one of a recess and a projection located at one of an outer peripheral portion of the first carrier and an inner peripheral portion of the second ring gear, and the other of the recess and the projection located at the other of the outer peripheral portion of the first carrier and the inner peripheral portion of the second ring gear; and a length in a circumferential direction of the recess is greater than a length in a circumferential direction of the projection. [11] Transmission according to one of claims 7 to 10, further comprising an output body, a second one-way clutch and a third one-way clutch, wherein the first ring gear is connected to the output body via the second overrunning clutch, and the second ring gear is connected to the output body via the third overrunning clutch. [12] A transmission for a human-powered vehicle, the transmission comprising: a first gear unit including a first gear path that changes a speed of rotation that is initiated; a second gear unit comprising a second gear path that changes a speed of rotation that is initiated, the second gear unit being configured to transmit rotation to the first gear unit; and a switching unit that changes a gear ratio of the human-powered vehicle in stages, whereby the first gear unit comprises a first planetary gear unit, the first transmission path comprises a plurality of paths, each having a different transmission ratio, the switching unit is designed to change a rotational state of at least one of the first gear unit and the second gear unit, to switch a transmission path of the rotation introduced into the first gear unit and the second gear unit, the switching unit is designed to be connected to one of the first transmission paths, comprising one of the plurality of paths, and the first transmission path comprising another of the plurality of paths, to the other of the first transmission path comprising one of the plurality of paths and the first transmission path comprising the other of the plurality of paths, such that the transmission path passes through the first transmission path, and in a case where the gear ratio is increased in stages, between a gear stage formed by a transmission path, which passes through a first transmission path comprising one of the plurality of paths receiving a first gear ratio, and a gear stage formed by a transmission path passing through the first transmission path comprising another of the plurality of paths receiving a smaller gear ratio than the first gear ratio, a gear stage is formed by a transmission path that does not pass through the first transmission path. [13] A transmission according to any one of claims 1 to 12, further comprising a hub that houses the first transmission unit, the second transmission unit and the switching unit. [14] A support system for a human-powered vehicle, the support system comprising: the transmission according to one of claims 1 to 13; and an engine that supports human propulsion. [15] The support system of claim 14, further comprising an actuating unit that is manually operated to operate the transmission, wherein the transmission changes a gear ratio of the human-powered vehicle according to the operation of the operating unit.

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