Bicycle hub, bicycle driveline, and methods of use thereof

Abstract

The invention relates to a bicycle hub, a bicycle driveline and a method of using the same. A bicycle hub includes a driver rotatable about an axis at a first rotational speed, wherein the driver includes a mating feature configured to engage a flywheel. The housing is rotatable about the axis at a second rotational speed. A non-adjustable gear train is coupled between the driver and the housing, wherein the gear train defines a single fixed gear ratio between the driver and the housing greater than 1: 1. A bicycle driveline includes: a drive unit having a user input member rotatable about a first axis at a first rotational speed; a link rotatable about a second axis at a second rotational speed; and a gear train coupled between the user input member and the chain ring. The gear train defines a gear ratio between the user input member and the chain ring of less than 1: 1. A method of propelling a bicycle is also provided.

Description

Technical Field

[0001] The present application relates generally to bicycle hubs that may be incorporated into a bicycle drive train and methods of using the same. Background Art

[0002] Bicycles are typically configured with a chain acting between one or more front chain rings and one or more rear sprockets of a cassette. The front and / or rear derailleurs may be actuated to enable the chain to shift / convert between chain rings and / or between different sprockets on a cassette. However, shifting under load may generate high tension in the chain, which may adversely affect the rapidity and smoothness of the shift, and may increase the likelihood of wear and damage to the drive train. The challenge of high chain tension may be exacerbated when the bicycle includes an electric motor to assist cranking. The electric motor supplements the user by providing additional input torque to the drive train. Due to control system limitations, the motor may continue to temporarily apply torque to the drive train after the user has reduced its torque input in preparation for commanding a shift. In this way, the drive train on a bicycle equipped with an electric motor ("e-bike") may be exposed to a higher tension load in the chain during shifting than in the case of a non-motor-assisted bicycle. During the shifting operation of the drive train, this may result in a higher likelihood of damage to the drive train itself, and also result in perceived rough shifting.

[0003] Additionally, electric motor assisted bicycles typically have a gear reduction between the motor output and the rider input, which reduces the relatively high revolutions per minute (rpm) and low torque of the electric motor to a more typical rider cadence and higher torque so that the motor input can operate in parallel with the rider input. The resultant torque and angular velocity (rpm) input into the drive train at the chain ring is in the range of a typical rider plus some increased torque assistance due to the motor, so the chain tension and associated drive train loads are higher than what might be experienced by a bicycle propelled solely by the rider input. Summary of the invention

[0004] In one aspect, an embodiment of a bicycle hub includes a driver rotatable about an axis at a first rotational speed, wherein the driver includes a mating feature configured to engage a flywheel. The housing includes a wheel attachment feature, wherein the housing is rotatable about the axis at a second rotational speed. A non-adjustable gear train is coupled between the driver and the housing, wherein the gear train defines a single fixed transmission ratio (or gear ratio) between the driver and the housing. The transmission ratio is greater than 1:1, such that the second rotational speed is less than the first rotational speed.

[0005] In another aspect, an embodiment of a bicycle transmission system includes a drive unit having a user input component capable of rotating about a first axis at a first rotational speed, a chain ring capable of rotating about a second axis at a second rotational speed, and a first gear train coupled between the user input component and the chain ring. The first gear train defines a first transmission ratio between the user input component and the chain ring, wherein the first transmission ratio is less than 1:1, such that the second rotational speed is greater than the first rotational speed. The bicycle hub includes: a driver capable of rotating about a third axis at a third rotational speed; a gear coupled to the driver and capable of rotating with the driver about the third axis at a third rotational speed; and a housing having a wheel attachment feature, wherein the housing is capable of rotating about the third axis at a fourth rotational speed. A second gear train is coupled between the driver and the housing, wherein the second gear train defines a second transmission ratio between the driver and the housing. The second transmission ratio is greater than 1:1, such that the fourth rotational speed is less than the third rotational speed. A closed loop component connects the chain ring and the gear.

[0006] In yet another aspect, an embodiment of a method of propelling a bicycle or using a drive train and a bicycle hub includes: rotating a crank about a first axis at a first rotational speed; simultaneously rotating a chain ring coupled to the crank about a second axis at a second rotational speed greater than the first rotational speed; simultaneously rotating a gear about a third axis at a third rotational speed, wherein the gear is coupled to the chain ring via a closed loop component; and simultaneously rotating a wheel about the third axis at a fourth rotational speed less than the third rotational speed.

[0007] Various embodiments of bicycle hubs and drive trains and methods of using and assembling the same provide significant advantages over other bicycle hubs, drive trains, and methods. For example, but not limited to, unlike a typical bicycle drive train in which the chain ring rotates at the same angular velocity or rotational speed as a user input component, a first gear train between the user input component and the chain ring causes the chain ring to rotate at a greater angular velocity than the user input component. Thus, a closed loop component, such as but not limited to, configured as a chain or belt, moves faster than a typical bicycle chain and has lower tension, resulting in reduced wear on the drive train. Because the closed loop component moves faster than a chain in a conventional bicycle that is not configured with a gear train, the flywheel rotates faster than a typical flywheel, and thus the shifting speed is increased because the shift gate on the flywheel interacts with the closed loop component more frequently. Unlike a typical bicycle rear hub in which the hub shell, and therefore the wheel, rotates at the same speed as the flywheel, the bicycle rear hub of the present invention has a second gear train between the flywheel and the hub shell so that the hub shell rotates at a slower angular velocity than the flywheel.

[0008] In one embodiment, the gear ratio of the first gear train can be the inverse of the gear ratio of the second gear train. In other words, the degree to which the chain ring rotates faster than the user input component is "offset" by the degree to which the hub shell rotates slower than the flywheel. As a result, the rear wheel rotates at the appropriate angular velocity relative to the angular velocity of the user input component. This embodiment also allows the use of conventional front and rear gear changers or derailleurs if desired. In essence, the closed loop components speed up to reduce chain tension, and the gear reduction in the rear hub slows down so that the rear wheel rotates at a predetermined speed. Therefore, the load input on the drive train is reduced to prevent damage during shifting and reduce the perception of rough shifting under load.

[0009] In conjunction with the motor, the transmission ratio of the output from the rider is matched to the high speed / low torque of the motor output, which works in parallel with the user input component. This results in an angular velocity output to the chain ring that is greater than the typical rider cadence, but with lower torque, even though the motor assists the torque. The gear reduction mechanism in the rear bicycle wheel hub then restores the desired transmission ratio, allowing conventional sized chain rings and rear flywheels or sprocket sets to be used. In this way, power is transmitted through the external drive train (chain rings, closed loop components, rear flywheel) at relatively low loads and high speeds, which reduces the likelihood of damage to the drive train and improves shifting performance. For example, the user's perceived time to complete a shift can be reduced. This is because the linear chain speed is increased, which is accompanied by a higher frequency of shift positions passed / experienced on the rear flywheel for a given riding speed when compared to a traditional bicycle drive train.

[0010] The preceding paragraphs have been provided by way of general introduction, and are not intended to limit the scope of the claims set forth below. Various preferred embodiments, together with further advantages, will be best understood by referring to the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which:

[0012] Figure 1 is a side view of an example of a bicycle.

[0013] Figure 2 is a rear view of one embodiment of a rear bicycle hub.

[0014] Figure 3 yes Figure 2 Left side view of the rear bicycle hub shown.

[0015] Figure 4 yes Figure 3 Right side view of the rear bicycle hub shown.

[0016] Figure 5yes Figure 2 Left perspective view of the rear bicycle hub shown.

[0017] Figure 6 yes Figure 2 A right perspective view of the rear bicycle hub is shown.

[0018] Figure 7 It is along Figure 3 A cross-sectional view of the rear bicycle wheel hub taken along line 7-7 in FIG.

[0019] Figure 8 It is along Figure 7 A cross-sectional view of the rear bicycle wheel hub taken along line 8-8 in FIG.

[0020] Fig. 9 It is along Figure 7 A cross-sectional view of the rear bicycle wheel hub taken along line 9-9 in FIG.

[0021] Fig.10 It is along Figure 7 A cross-sectional view of the rear bicycle wheel hub taken along line 10-10 in FIG.

[0022] Fig.11 yes Figure 2 A rear view of a rear bicycle hub is shown with a brake rotor and a flywheel mounted thereon.

[0023] Fig.12 yes Fig.11 A left side view of a rear bicycle hub assembly is shown.

[0024] Fig.13 It is along Fig.12 A cross-sectional view of the rear bicycle hub assembly taken along line 13-13 in FIG.

[0025] Fig.14 It is along Fig.13 A cross-sectional view of the rear bicycle hub assembly taken along line 14-14 in FIG.

[0026] Fig.15 is a right side view of one embodiment of a bicycle drive train.

[0027] Fig.16 It is along Figure 1 A cross-sectional view of a bicycle transmission system taken along line 16-16 in FIG.

[0028] Fig.17 It is along Fig.16 A cross-sectional view of a bicycle transmission system taken along line 17-17 in FIG.

[0029] Fig.18 is a schematic diagram of one embodiment of a bicycle drive train.

[0030] Fig.19 is a schematic diagram of another embodiment of a bicycle transmission train. DETAILED DESCRIPTION

[0031] It should be understood that the term "plurality" as used herein refers to two or more. As used herein, the term "longitudinal" refers to or relates to a length direction or a longitudinal direction. As used herein, the term "lateral" refers to being located in a lateral / left-right direction, pointing in a lateral / left-right direction, or extending in a lateral / left-right direction. The term "coupled" refers to being connected to or joined directly or indirectly (e.g., using an intermediate member), and does not require the joining to be fixed or permanent, although it can be fixed or permanent. The terms "first", "second", etc. as used herein are not meant to be assigned to a specific component so designated, but simply refer to such components in the numerical order mentioned, meaning that a component designated as "first" may later be a "second" such component, depending on the order in which it is referenced. It should also be understood that the designation of "first" and "second" does not necessarily mean that the two components or values ​​so designated are different, meaning that, for example, the first axis may be the same as the second axis, where each is simply applicable to different components. The terms "upper", "lower", "back", "front", "front", "back", "vertical", "horizontal", "right", "left", "inside", "outside" and variations or derivatives thereof refer to Figure 1 The illustrated exemplary bicycle 150 is oriented from the perspective of a user seated thereon, such that "inboard" components or features are closer to a vertical mid-plane of the bicycle extending in direction A. The term "lateral" means non-parallel. The terms "outer" and "outward" refer to directions or features that point away from a central location, such as the phrases "radially outward," "radial directions," and / or their derivatives refer to features that point away from a central location, such as Figure 1 and Fig.16 The chainring assembly is shown with its axis of rotation 120. In contrast, the terms "inwardly" and "inwardly" refer to directions toward a central or interior position. The term "subassembly" refers to an assembly of multiple components, wherein the subassembly is capable of being further assembled into other subassemblies and / or a final assembly, such as bicycle 150.

[0032] bike

[0033] Figure 1An example of a human-powered vehicle is shown. In this example, the vehicle is a bicycle 150 of one possible type, such as a mountain bike. The bicycle 150 has a frame 1, a handlebar 154 near the front end of the frame, and a seat or saddle 156 for supporting a rider on top of the frame. In the example shown, the saddle 156 is supported on a seat post 181 having an end received in the top of a frame seat tube 89 of the frame. A clamping ring 191 can be tightened to secure the upper seat post 181 to the lower frame seat tube 189. The bicycle 150 has a first wheel or front wheel 158 supported by the front fork subassembly 60 supporting the front end of the frame. The bicycle 50 also has a second wheel or rear wheel 162 supporting the rear end of the frame 1. The rear wheel 162 includes a rim 261 that supports a tire. The rear end of the frame includes a rear chain stay 163 and a rear seat stay 165 that can be supported by a rear suspension component 161 such as a rear shock absorber.

[0034] The bicycle 150 includes a transmission system 164 as a set of components that transfer power from a drive input such as a user input component 176 (e.g., pedals) and / or a drive unit 2 (e.g., an electric motor) to a driven component such as a rear wheel 162. It should be understood that the driven component may include a front wheel, or a front wheel and a rear wheel, or some other component. Figure 1 , Fig.15 , Fig.16 , the transmission system 164 has a drive input end 166, which includes a crank assembly 167, which is operably coupled to a rear flywheel 6 or a driven sprocket assembly mounted on a hub assembly 7 via a closed loop component 5, and the hub assembly 7 provides a rotation axis of the rear wheel 162 (i.e., the driven component). The closed loop component 5 can be configured as a chain, such as a roller chain or a belt (with or without teeth). A rear gear change device 137 (such as a derailleur) can be provided at the rear wheel 162 and, for example, connected to the frame 1 to move the roller chain 5 through different sprockets 361 of the flywheel 6. In various embodiments, the flywheel 6 includes a plurality of sprockets 361, each sprocket having a different diameter and an associated number of gear teeth, which provide a plurality of transmission ratios / gear ratios when coupled to the chain ring assembly 3 through the closed loop component 5. The sprocket 361 may have a shift gate, such as a feature formed in the sprocket or sprocket structure, that engages / interfaces with the closed loop member 5 to facilitate shifting between the sprockets 361. In one embodiment, a front gear changer device such as a derailleur may be connected to the frame to move the roller chain 5 through the multiple sprockets of the chainring assembly.

[0035] like Figure 1 As shown, arrow A depicts the normal riding or forward movement direction of bicycle 150. Figure 1The bicycle 150 depicted in the drawings is a mountain bike, but the drivetrains including the specific embodiments and examples and alternative embodiments and examples disclosed herein can be implemented on other types of bicycles. For example, but not limited to, the disclosed drivetrains can be used on road bicycles and can be controlled / actuated by mechanical (e.g., cables, hydraulics, pneumatics, etc.) and non-mechanical (e.g., wired, wireless) actuator systems (including, for example, shifters).

[0036] Drivetrain

[0037] refer to Figure 1 , Fig.15 , Fig.16 , the crank assembly 167 includes a user input component. In one embodiment, the user input component includes at least one and typically two crank arms 4 and associated pedals 176, and a front chain ring assembly 3 or a drive sprocket assembly. The crank spindle 61 (also referred to as the crank shaft 61) connects the two crank arms 4. The crank shaft 61 is coupled to the output shaft 79 through a gear train 300, 370. In Fig.15 In the illustrated embodiment, the rotational axes 201, 203 of the output shaft 79 and the crankshaft 61 are spaced apart. Fig.16 In the embodiment of FIG. 5 , the output shaft 79 and the crankshaft 61 are coaxial and rotatable about the same rotation axis 2 of the chain ring assembly 3 .

[0038] exist Figure 1 , Fig.15 and Fig.16 In the embodiment of , the drive input for the transmission system 164 includes both the user input component 4, 176 and the drive unit 2, but it should be understood that one or the other of the user input component and the drive unit may be idle so that only the other of the user input component and the drive unit is used as the drive input.

[0039] The drive unit 2 is mounted on the frame 1 of the bicycle. The drive unit 2 includes an electric motor 304 and a gear train 306 connected between the electric motor 304 and the output shaft. Fig.16, the drive unit 2 includes a housing 60 that can be mounted on a vehicle frame. The housing 60 has opposing sides 260 with openings or holes 308, 310. The main shaft bearings 63 and the output shaft bearings 86 are disposed in the holes 308, 310 and supported by the sides 260. The first end 312 of the output shaft 79 is supported by the second output shaft bearing 86, and the second end 314 of the output shaft 79 is supported by the first output shaft bearing 85, which is disposed on the outer surface 316 of the crank spindle 61. The output shaft 79 is rotatable relative to the housing 60 about the rotation axis 120. The second main shaft bearing 64 is disposed in the inner bore 320 of the output shaft 79. The crank spindle 61 is supported by the first main shaft bearing 63 and the second main shaft bearing 64. The crank spindle 61 is rotatable relative to the housing 60 and the output shaft 79. The crank arm 4 is rotationally fixed to the crank spindle 61 by a spline interface, but the interface can also be configured as a socket and an insert or other fastener. The phrase "rotationally fixed" means that two or more components are non-rotatable relative to each other, even if the two or more components can rotate together relative to another component. In this way, the spindle 61 is rotationally fixed to the crank arm 4 and can rotate with the crank arm 4. The crank arm 4 is axially retained to the spindle 61 by a pair of laterally / laterally spaced retaining nuts 62. The outer periphery of the first bearing support structure 67 and the second bearing support structure 68 is disposed in the inner hole of the housing 60, and is preferably rotationally fixed to the housing 60 by a spline interface, pins, fasteners or other structures. The first motor bearing 69 and the second motor bearing 70 are respectively disposed in the inner periphery of the first bearing support structure 67 and the second bearing support structure 68.

[0040] In one embodiment, the gear train 306 is configured as an epicyclic gear train. In one embodiment, the planetary gear train 306 has a first planetary gear stage 330 and a second planetary gear stage 332. In one embodiment, the first planetary gear stage 330 includes a sun gear 71, a planet carrier 74, a plurality of planetary gears 72, and an annular gear (ring gear) 80. The sun gear 71 is engaged with and supported by the first motor bearing 69 and the second motor bearing 70. The sun gear 71 is rotatable relative to the housing 60 about the rotation axis 120. The sun gear 71 has an outer circumferential surface 333 configured with a plurality of gear teeth 334. The motor 304 includes a rotor 66, which is fixed to the sun gear 71 in a rotationally fixed manner, for example, by a spline interface or other fasteners. The motor 304 also includes a stator 65, which is fixed to the housing 60 in a rotationally fixed manner, for example, using a spline interface or other fasteners. Ring gear 80 is laterally spaced from motor 304 and is rotationally fixed to housing 60, for example, using a spline interface or other fasteners, such as Fig.16 and Fig.17 As shown. The ring gear 80 has an inner circumferential surface 340 configured with a plurality of gear teeth 342. The gear train 306 includes a plurality of circumferentially spaced planet gears 72 radially spaced from the rotation axis 120. Each planet gear 72 has an outer circumferential surface 346 configured with a plurality of gear teeth 348. The gear teeth 348 of the planet gears 72 meshingly engage with the gear teeth 342 of the ring gear 80. In one embodiment, the gear train 306 and in particular the first gear stage 330 includes eight circumferentially spaced planet gears 72, but it should be understood that more or fewer planet gears may be used. Each planet gear 72 is rotatably supported by a shaft 73. The shaft 73 is mounted to a planet carrier 74. The gear teeth 348 of the planet gears 72 also meshingly engage with the gear teeth 334 of the sun gear 71.

[0041] The second planetary gear stage 332 includes a plurality of circumferentially spaced planetary gears 75 radially spaced from the axis of rotation 120. Each planetary gear 75 has an outer circumferential surface 350 configured with a plurality of gear teeth 352, which meshingly engage with the gear teeth 342 of the ring gear 80. In one embodiment, the gear train 306, and in particular the second gear stage 332, includes eight circumferentially spaced planetary gears 75, but it should be understood that more or fewer planetary gears may be used. Each planetary gear 75 is rotatably supported by a shaft 76 mounted to a planet carrier 77. The gear teeth of the second motor planetary gears 75 also meshingly engage with the gear teeth 360 on the outer circumferential surface 364 of the hub portion 362 extending axially from the planet carrier 74. Therefore, the planet carrier 74, and in particular the hub portion 362, serves as a sun gear for the second planetary gear stage 332, which includes the planet carrier 74, the planet carrier 77, the planetary gears 75, and the ring gear 80. The planet carrier 74 is the output of the first planetary gear stage 330 , and it is also the input of the second planetary gear stage 332 .

[0042] A one-way motor clutch 78 is provided between the planet carrier 77 and the output shaft 79. The motor clutch 78 may include a spring-loaded pawl, etc. The motor clutch 78 is configured and arranged to transfer torque from the second motor planet carrier 77 to the output shaft 79, but is also configured and arranged so that torque from the output shaft 79 cannot be transferred to the planet carrier 77. In other words, the planet carrier 77 drives the output shaft 79, but the output shaft 79 cannot drive the planet carrier 77.

[0043] refer to Fig.16 and Fig.17, the gear train 370 for the user input component is configured as a planetary gear train, which includes a plurality of planet gears 84, a planet carrier 82, a ring gear 80 and an output shaft 79. The plurality of planet gears 84 are circumferentially spaced apart, wherein each planet gear has an outer circumferential surface 372 configured with a plurality of gear teeth 374. The gear teeth 374 meshingly engage with the gear teeth 342 of the ring gear 80, and also meshingly engage with the gear teeth 376 formed on the outer circumferential surface 378 of the output shaft 79. In one embodiment, the gear train 370 includes eight circumferentially spaced apart planet gears, but it should be understood that more or fewer planet gears may be used. Each planet gear is rotatably supported by a planet shaft 83 mounted on the planet carrier 82. In one embodiment of the gear train, the ring gear 80 is fixed against rotation, the planet carrier 82 is the input end, and the output shaft 79 is the output end via the sun gear 71.

[0044] In one embodiment, the ring gear 80 has 108 teeth, the planet gears 84 have eighteen (18) teeth, and the output shaft 79 (via the sun gear 71) has sixty-eight (68) teeth. The gear ratio is defined as the ratio of the angular velocity of the input relative to the output. In this embodiment, the gear ratio is less than 1:1 in the case where the chain ring 3 or the output rotates faster than the main shaft 61 or the input. In particular, when the ring gear is held stationary and the sun gear is used as the output, the planet carrier will be the input, as shown in FIG. Fig.18 and Fig.19 As shown. In this case, the transmission ratio will be (Nsun) / (Nsun+Nring), or 68 / (68+108) or 1:2.6, where N=number of gear teeth. In other embodiments, the transmission ratio is between 1:2 and 1:3, and preferably less than 1:1. It should be understood that other sun gears or ring gears can be input ends, and other carriers and ring gears can be output ends to achieve a transmission ratio between the input and output ends that is less than 1:1. The gear train may include a one-way clutch 81 disposed between the crank spindle 61 and the rider planet carrier 82. The clutch 81 is configured and arranged to transfer torque from the spindle 61 to the planet carrier 82, and is also configured and arranged so that torque from the planet carrier 82 cannot be transferred to the spindle 61. In other words, the crank spindle 61 can drive the planet carrier 82, but the planet carrier 82 cannot drive the crank spindle 61.

[0045] refer to Fig.16 The chain ring 3 is fixed to the output shaft 79 in a rotationally fixed manner, for example, by a spline interface, a socket interface or other fasteners, and is axially retained to the output shaft 79 by a chain ring locking nut 87. Therefore, the chain ring 3 is fixed to the output shaft 79 in a rotationally fixed manner and can rotate together with the output shaft 79 about the rotation axis 120.

[0046] Reference Fig.15 , another embodiment of a gear train 300 coupled between a crank arm 4 and a chain ring 3 is shown. In this embodiment, the gear train 300 includes a chain ring 38 fixed to the crank arm 4 in a rotationally fixed manner. In one embodiment, the chain ring 38 has an outer periphery configured with a plurality of teeth. In one embodiment, the chain ring 38 has 40 teeth. The gear train 300 includes a sprocket gear 40, which is rotatably mounted on the bicycle frame about a rotation axis 203, such as on an axle 79 defining the axis 203. The axis 203 is parallel to but spaced apart from the rotation axis 201 of the crank arm 4. In one embodiment, the sprocket gear 40 has sixteen (16) teeth. A closed loop member 39, such as a chain or belt, engages both the chain ring 38 and the sprocket gear 40. A chain ring 41 is fixed to the sprocket gear 40 in a rotationally fixed manner. In one embodiment, the chain ring 41 has the same number of teeth as the chain ring 3. In this gear train, the drive member or chain ring 38 rotates one revolution for every four revolutions of the sprocket gear 40 and the chain ring 41, resulting in a transmission ratio of 1:4 or less than 1:1. The closed loop member 5 (e.g., a chain or belt) may engage both the chain ring 41 and one of the sprocket gears on the cassette 6, depending on the position of the rear derailleur. In this embodiment, the drive unit 2 may be coupled to the output shaft 79, for example, using a gear train 306.

[0047] In an alternative embodiment, the gear train between the user input component and the chain ring may include a spur gear that can be fixed to the crank arm in a non-rotational manner and directly meshes with a pinion gear mounted to the shaft and fixed to the chain ring in a non-rotational manner. The first spur gear and the second spur gear provide a transmission ratio of less than 1:1. In another embodiment, the gear train may include a pair of pulleys connected to the belt, wherein the input pulley connected to the crank arm has a larger diameter than the output pulley connected to the chain ring 41. In other embodiments, the gear train may be configured with more than one set of chain rings and sprockets, spur gears and pinions (whether meshed with or connected to the belt) and / or pulleys and belts, or the gear train may be configured with a combination of chain rings, sprockets, spur gears and pinions and pulleys and / or belts, the combination of which results in a transmission ratio between the input end (e.g., shaft 61) and the output end (e.g., chain rings 3, 41) of less than 1:1.

[0048] Reference Figures 7 to 11The bicycle hub assembly 7 includes a driver 8, which is rotatably supported on the outer circumferential surface 400 of the hub axle 20 using an inner bearing 25 and an outer bearing 26. The driver 8 can be configured as a shaft and has a tubular structure with an inner circumferential surface and an outer circumferential surface. The shaft 20 is non-rotatably or rotationally fixed relative to the frame 1 and is preferably made of aluminum. The bearings 25, 26 are laterally or axially spaced apart by an inner spacer 32 and an outer spacer 33. In one embodiment, the spacers 32, 33 are tubular and coaxially mounted on the hub axle 20. The driver 8 is rotatably supported by the outer rings of the bearings 25, 26 so that the driver 8 can rotate relative to the hub axle 20 about the axis 414. The spacer 34 abuts the inner ring of the outer bearing 26.

[0049] Reference again Figures 7 to 10 , the non-rotatable ring gear 13 is non-rotatably fixed to the hub axle 20, for example, by a spline interface 13a, which includes a splined inner surface that engages a complementary splined surface on the outer surface 400 of the hub axle 20. Therefore, the ring gear 13 is non-rotatably fixed to the hub axle 20. In one embodiment, the ring gear 13 has an inner circumferential surface 402 configured with a plurality of teeth 404. In one embodiment, the inner circumferential surface 402 includes one hundred and eight (108) teeth, but it should be understood that the ring gear 13 can have more or fewer teeth. The spacer 31 separates the ring gear 13 from the laterally / laterally spaced inner ring of the inner side bearing 25. The non-drive side bearing 27 is disposed on and supported by the outer surface 400 of the hub axle 20, and the drive side bearing 28 is disposed on and supported by the outer circumferential surface 406 of the laterally / laterally extending hub portion 408 of the ring gear 13. The outer races of the bearings 27, 28 are disposed in laterally / laterally spaced holes 410, 412 formed in the end of the hub shell 18. Thus, the hub shell 18 is rotatable relative to the hub axle 20 about an axis 414 defined by the hub axle 20. The spacers 30 abut the laterally / laterally spaced inner races of the bearings 27, 28 and separate them.

[0050] Reference Figure 4 , Figure 6 and Figure 7 , the planet carrier 14 has a scalloped outer periphery 14a that engages with a complementary scalloped inner periphery 14b of the hub shell 18. A protrusion 420 on the carrier engages with a recess 422 in the shell, but the protrusion and recess may be reversed. A plurality of fasteners 19, shown as six (6) screws, are provided through holes in the planet carrier 14 and threadingly engage holes in the hub shell 18. Thus, the planet carrier 14 is rotationally fixed to the hub shell 18 and is rotatable therewith about the axis 414.

[0051] A plurality of circumferentially spaced shafts 15 are coupled to the carrier 14 and are radially spaced from the axis 414. The shafts 15 may be coupled to the web of the carrier 14 by a threaded fit or a press fit. The shafts 15 are rotationally fixed to the planet carrier 14 and rotate with the planet carrier 14 about the axis 414. Alternatively, more or fewer planet shafts 15 may be used.

[0052] refer to Figure 7 and Figure 8 , a planetary gear 12 is mounted on each shaft 15 and rotates about an axis defined by the shaft 15. Therefore, the planetary gears 12 are rotatable relative to the planetary shafts 15, and the number of planetary gears 12 is equal to the number of planetary shafts 15. Each planetary gear 12 is axially retained on a corresponding planetary shaft 15 by a planetary shaft cover 16, which is screwed to its planetary shaft 15 by a fastener 15 (e.g., a screw). Each planetary gear 12 includes a plurality of teeth 430 on its outer circumferential surface. The gear teeth 430 of the planetary gears meshingly engage with the gear teeth 404 of the ring gear 13. In one embodiment, each planetary gear 12 has eighteen (18) teeth 430, but it should be understood that more or fewer teeth may be provided.

[0053] The sun gear 11 has an inner circumferential surface 434 configured with a plurality of teeth 436. The sun gear 11 is rotatably supported by an outer circumferential surface 460 of the driver 8. The sun gear 11 has an outer circumferential surface 462 configured with a plurality of gear teeth 464, which meshingly engage the gear teeth of the planet gears 12. In one embodiment, the sun gear 11 has sixty-eight (68) gear teeth 464, but it should be understood that the sun gear can be configured with more or fewer gear teeth. Therefore, the sun gear 11, the planet gears 12 and the ring gear 13 together form a planetary gear train 470, wherein the ring gear 13 is stationary relative to the hub shaft 20, the driver 8 and the sun gear 11 serve as the input end of the gear train, and the planet carrier 14 and the housing 18 serve as the output end of the gear train 470. In this embodiment, in the case where the driver 8 rotates faster than the housing 18, the gear ratio is greater than 1:1. In particular, when the ring gear 13 remains stationary and the sun gear 11 serves as the input end, the planet carrier 14 will be the output end. In this case, the transmission ratio will be (Nsun+Nring) / Nsun, or (68+108) / 68, or 2.59:1 or 2.6:1, or greater than 1:1. In one embodiment, the transmission ratio is between 2:1 and 3:1. It should be understood that the planet carrier can be the input end and the ring gear can be the output end, or the sun gear can be the input end and the ring gear can be the output end, or the sun gear can be the input end and the planet carrier can be the output end (such as Fig.18 and Fig.19As shown), to achieve a transmission ratio between the input end and the output end greater than 1:1. In the case of a transmission ratio of approximately 2.59:1, the planet carrier 14 rotates once per rotation every time the sun gear 11 rotates 2.59 times per rotation. Alternatively, other transmission ratios may be used. Moreover, as previously described, the gear train 470 may be configured with multiple gear stages and may include one or more spur gears and pinions or pulleys and belts with offset axes, the combination of which results in a transmission ratio between the input end (e.g., the driver 8) and the output end (e.g., the hub shell 18) greater than 1:1.

[0054] The gear train may include a one-way clutch 91 disposed between the rear cog gear set 6 (via the driver 8) and the sun gear 11. The clutch 91 is configured to transfer torque from the rear cog gear set 6 to the sun gear 11, and is also configured so that torque from the sun gear 11 cannot be transferred to the rear cog gear set 6. In other words, the rear cog gear set 6 can drive the sun gear 11, but the sun gear 11 cannot drive the rear cog gear set 6.

[0055] The gear train 470 coupled between the driver 8 and the housing 18 is non-adjustable, meaning that when the gear train 470 is engaged, the gear train 470 has a fixed gear ratio between the driver 8 and the hub housing 18. In one embodiment, the term "non-adjustable" refers to the fact that the hub does not have any axially displaceable parts, meaning that the driver, sun gear, carrier, ring gear and hub are all axially fixed relative to each other. That is, it is contemplated that the non-adjustable gear train 470 can also be disengaged. For example, the ring gear can be released from the ground or connection with the shaft 20 and allowed to rotate. A ratchet mechanism 9 can be provided between the ring gear and the sun gear to prevent reverse relative rotation between the sun gear and the ring gear, thereby locking the gear train, wherein the driver 8 drives the hub 18 with a 1:1 gear ratio. Similar features can be incorporated into the gear train 370, which may be beneficial, for example, when the motor 304 is disabled (such as when the battery is low). In another embodiment, when engaged, the gear ratio is always greater than 1:1. In an embodiment, as Fig.19As shown, the actuator 95 (or locking actuator) allows the rider to reversibly disengage any one or combination of the gear trains 370, 470 so that the corresponding gear trains operate at a 1:1 gear ratio. The actuator 95 can be mounted on the bicycle so that it is easy to be operated by the rider, for example, mounted on the handlebars, top tube, head tube, stem or down tube of the bicycle. The actuator 95 can be physically connected to the gear train (e.g., via a cable) to physically reversibly disengage the gear train so that it operates at a 1:1 gear ratio. The actuator 95 can also be a wireless controller wirelessly connected to a corresponding wireless receiver in the gear train 370, 470, which is configured to reversibly disengage the corresponding gear train so that it operates at a 1:1 gear ratio. The wireless controller can be integrated into a head unit or a multi-purpose wireless control device so that a separate wireless controller for reversibly disengaging the gear train is not required.

[0056] refer to Figure 7 , spacers 35 are provided on shoulders 490 on each lateral side of the sun gear 11. The spacers 35 may be made of a soft material such as acetal or nylon, and prevent the metal side surface of the sun gear 11 from contacting the metal side surface of other components in the system when the sun gear 11 moves slightly in the axial direction. The rubber seal 36 is provided in a groove in the driver body 8, and blocks foreign debris from entering the system through the gap between the driver body 8 and the planet carrier 14.

[0057] refer to Figure 8 , a plurality of circumferentially spaced pawls 9 are pivotally connected to the drive body. In one embodiment, four evenly spaced pawls 9 are placed in a pawl recess 492 in the driver body 8 in a conventional manner. Each pawl 9 has a corresponding pawl spring 10 also disposed in each pawl recess 492. The pawl spring 10 is configured to bias the tip of the pawl 9 radially outward into engagement with the teeth 436 defining the toothed inner profile 11a of the sun gear 11. In one embodiment, only a subset of the plurality of pawls 9 (for example, two of the four pawls shown) actively engage the teeth 436 of the sun gear 11, while the other two pawls are disengaged from the teeth. The number of teeth 436 on the toothed inner profile 11a of the sun gear 11 is selected so that one pair of pawls (opposite to each other) is "out of phase" with the other pair of pawls, resulting in a smaller maximum angle that the driver body 8 must rotate through in order for a pair of pawls 9 to engage the teeth in the sun gear 11. Preferably, the number of teeth 436 in the toothed inner profile 11a of the sun gear 11 is 26. The pawl 9 engages the sun gear 11 in only one direction of rotation, but disengages from the sun gear in the opposite direction of rotation.

[0058] refer to Figure 7 , Fig.10 and Fig.12The non-rotatable torque arm 24 or frame engagement feature has a splined inner profile 24c or inner circumferential surface that engages a complementary splined profile on the outer circumferential surface of the hub axle 20. The splined interface rotationally secures the torque arm 24 to the hub axle 20. The non-drive side spacer 29 is disposed in a recess in the end of the hub axle 20.

[0059] refer to Fig.11 , the brake rotor 22 is fixed to the hub shell 18 of the rear hub assembly 7. A plurality of fasteners, shown as six (6) bolts 23, couple the brake rotor 22 to the hub shell 18. The flywheel 6 is rotationally fixed to the driver 8. In one embodiment, a threaded element of the flywheel 6 is screwed onto the threaded portion 8b of the driver body 8, and a female spline in the flywheel 6 engages a corresponding male spline 8a on the driver body 8. The spline interface 8a and the threaded portion 8b define mating features for the flywheel, wherein the spline interface 8a rotationally fixes the flywheel 6 to the driver body 8. The driver body 8 has a flywheel receiving portion 363 including the spline interface 8a and the threaded portion 8b, which extends axially from the hub shell and has a length L suitable for accommodating the flywheel 6, and the flywheel 6 is configured with a plurality of sprockets 361 having different tooth configurations. In one embodiment, the flywheel 6 has a width W. In various embodiments, the flywheel 6 includes at least two (2) sprockets, but may have any suitable number of sprockets 361, including, for example, Fig.11 Twelve (12) sprockets are shown. The flywheel 6 may be configured as a separate subassembly, or the sprockets 361 may be mounted separately on the drive.

[0060] The hub shell 18 also includes a pair of laterally / laterally spaced annular spoke flanges 500, 504, each having a plurality of circumferentially spaced openings 502, 506 or wheel attachment features. In one embodiment, the wheel includes spokes 508 that are coupled or attached to the flanges 500, 504 by inserting the ends through the openings 502, 506, thereby attaching the wheel 162 to the hub shell 18. It should be understood that the wheel 162 can be attached to the hub assembly using integrally formed spokes or webs so that the hub shell and the wheel are integral. In this embodiment, the portion of the shell that connects to the feature extending between the hub shell and the rim of the wheel can be considered a wheel attachment feature.

[0061] like Fig.12 and Fig.13As shown, the rear hub assembly 7 is coupled to the frame 1 via a through shaft 21. The torque arm 24 of the rear hub assembly 7 has a surface 24a that abuts against the lower surface of the chain stay 163 portion of the bicycle frame 1. Optionally, a zip tie 50 can be passed through a hole 24b in the torque arm 24 and fixed to the chain stay 163 to ensure that the surface 24a of the torque arm 24 remains in contact with the bicycle frame 1. The through shaft 21 passes through a hole in the left frame member 1a of the frame 1, and passes through the hollow hub shaft 20 of the hub assembly 7, and is screwed into a threaded hole in the right frame member 1b of the frame 1. When the through shaft 21 is tightened, the shaft 21 axially compresses the left frame member 1a, the non-drive side spacer 29, the torque arm 24, the inner ring of the non-drive side hub shell bearing 27, the hub shell bearing spacer 30, the inner ring of the drive side hub shell bearing 28, the ring gear 13, the ring gear spacer 31, the inner ring of the drive body inner bearing 25, the drive body inner spacer 32, the inner ring of the drive body outer bearing 26, the drive side spacer 34 and the right frame member 1b of the frame 1.

[0062] operate:

[0063] The method for propelling the bicycle 150 includes rotating the crank arm 4 about the first axis 120, 201 at a first rotational speed, rotating the chain ring 3, 41 connected to the crank arm via a gear system about a second axis 120, 203 that may be coaxial with the first axis 120 at a second rotational speed greater than the first rotational speed, rotating a gear (e.g., a flywheel 6) about a third axis 414 at a third rotational speed, and rotating the wheel 162 about the third axis 414 at a fourth rotational speed less than the third rotational speed, wherein the gear 6 is connected to the chain ring 3, 41 via a closed loop component 5.

[0064] Specifically and with reference Figure 1 , Fig.16 , Fig.18 and Fig.19In the embodiment of the present invention, when the rider pedals (i.e., rotates) the crank arm 4, the crank arm 4 drives the main shaft 61. The main shaft 61, which is acted upon by the rider clutch 81, drives the rider planet carrier 82. The rider planet carrier 82 drives the rider planet shaft 83, which in turn drives the rider planet 84. The rider planet carrier 82, the rider planets 84, the ring gear 80, and the output shaft 79 together form the planetary gear train 370. Since the ring gear 80 is fixed (i.e., prevented from rotating), the planet gears 84 drive the output shaft 79 at a faster angular velocity than the angular velocity of the rider planet carrier 82. As previously described, the transmission ratio is approximately 1:2.6, which means that the rotation of the output shaft 79 is 2.6 times the rotation of the rider planet carrier 82. The output shaft 79 drives the chain ring 3. Therefore, the rotation of the chain ring 3 is 2.6 times the rotation of the crank arm 4. At the same time, the chain ring 3 drives the bicycle chain 5. The bicycle chain 5 drives the flywheel 6 by engaging any sprocket on the flywheel.

[0065] Reference now Fig.15 In the embodiment of the present invention, in operation, the rider pedals the crank 4 at a first angular velocity. Since the chain ring 38 is fixed to the crank 4, the chain ring 38 also rotates at the first angular velocity. The chain ring 38 drives the first chain 39. The first chain 39 drives the sprocket 40. Since the ratio of the number of teeth on the chain ring 38 to the number of teeth on the sprocket 40 is 40:16 or 2.5:1, the first sprocket 40 rotates at a second angular velocity that is 2.5 times the first angular velocity. Since the chain ring 41 is fixed to the first sprocket 40, the second chain ring 41 also rotates at a speed that is 2.5 times the first angular velocity. Therefore, the rotation of the second chain ring 41 is 2.5 times the rotation of the crank 4. The second chain ring 41 drives the chain 5, and the chain 5 drives the flywheel 6.

[0066] Reference now Figure 8 and Fig.13 , the flywheel 6 drives the driver body 8. The driver body 8 is driven clockwise by the flywheel 6. A pair of pawls 9 on the driver body 8 engage the toothed inner profile 11a of the sun gear 11, thereby driving the sun gear 11 clockwise. The sun gear 11 drives the planetary gears 12 and the planet carrier 14 in the clockwise direction but at a slower rotational angular velocity than the sun gear 11. The reaction force exerted by the planetary gears 12 on the ring gear 13 applies a counterclockwise torque to the ring gear. However, due to the connection to the hub axle 20, the ring gear 13 is fixed against rotation. The hub axle 20 is prevented from rotating by engaging the frame 1 with the torque arm 24, and the surface of the torque arm 24 abuts the bicycle frame 1. In other words, the reaction torque acting on the fixed ring gear 13 is transmitted from the ring gear 13 to the bicycle frame 1 via the hub axle 20 and via the torque arm 24.

[0067] The planet carrier 14 drives the hub shell 18 in a clockwise direction. The hub shell 18 drives the rear wheel 162 via the wheel spokes 508 in a clockwise direction (ie, the forward driving direction of the bicycle).

[0068] Preferably (but not necessarily), the drive unit 2 also includes the previously described electric motor 304, which assists the rider in pedaling as described below. Fig.16 and Fig.18 As shown, the motor stator 65 receives power from the battery 307. In response to the magnetic field generated by the stator 65, the motor rotor 66 rotates in the driving rotation direction. The motor rotor 66 drives the sun gear 71. As previously described, the sun gear 71 is the input end of the first planetary gear stage 330 of the gear train, which includes the sun gear 71, the first motor planet carrier 74, the first motor planet 72 and the ring gear 80. Since the ring gear 80 is fixed, the first motor planet carrier 74 is driven at a slower rate than the sun gear 71, but with increased torque. The first motor planet carrier 74 is also the input end (i.e., the sun gear) of the second planetary gear stage described previously, which includes the first motor planet carrier 74, the second motor planet carrier 77, the second motor planet 75 and the ring gear 80. Since the ring gear 80 is fixed, the second motor planet carrier 77 is driven at a slower angular velocity than the first motor planet carrier 74, but with increased torque. The second motor planet carrier 77 drives the output shaft 79 through the motor clutch 78. As previously mentioned, the output shaft 79 drives the chain ring 3. Therefore, the electric motor 304 can assist the rider in driving the chain ring 3.

[0069] It should be noted that in the event that the motor 304 is unable to assist the rider (e.g., if the battery loses power), the motor clutch 78 will be "overrun" by the rider's pedaling, meaning that when the output shaft 79 is driven by the rider, the output shaft 79 does not drive the first planetary gear stage 330 and the second planetary gear stage 332 (i.e., the motor gear stage), thereby eliminating the undesirable pedaling resistance that would be generated when rotation of the motor planetary gear stage is required.

[0070] It should also be noted that the rider clutch 81 prevents the electric motor 304 from driving the pedal cranks 4. The rider clutch 81 allows the main shaft 61 to be "overtaken" by the rider planet carrier 82. In other words, even if the rider planet carrier 82 is driven by the motor 304, due to the configuration of the rider clutch 81, the rider planet carrier 82 cannot drive the main shaft 61.

[0071] The motor controller 600 is operably connected to the motor 304. A rider torque sensor 603 applied to, for example, a chain ring provides input to the motor controller 600 regarding the user's torque input. Likewise, a motor torque feedback sensor 604 provides input to the motor controller 600 regarding the torque input of the motor 304. In this way, the controller 600 can adjust and modify the power supplied by the motor 304 relative to the user's torque input.

[0072] The illustrations of the embodiments described herein are intended to provide a general understanding of the structures of the various embodiments. The illustrations are not intended to be used as a complete description of all elements and features of the equipment and systems utilizing the structures or methods described herein. Upon reading this disclosure, many other embodiments may be apparent to those skilled in the art. Other embodiments may be utilized and derived from this disclosure so that structural and logical replacements and changes may be made without departing from the scope of this disclosure. In addition, the illustrations are merely representative and may not be drawn to scale. Certain proportions in the illustrations may be exaggerated, while other proportions may be minimized. Therefore, this disclosure and the accompanying drawings should be considered illustrative rather than restrictive.

[0073] Although this specification contains many details, these details should not be interpreted as limitations on the scope of the present invention or the content that can be claimed, but as descriptions of features specific to a particular embodiment of the present invention. Certain features described in the context of a separate embodiment in this specification may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination. In addition, although features may be described above as acting in certain combinations and even initially claimed as such, in some cases, one or more features from the claimed combination may be removed from the combination, and the claimed combination may involve a sub-combination or a variation of the sub-combination.

[0074] Similarly, although operations and / or actions are depicted in the accompanying drawings and described herein in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in a sequential order, or that all of the operations shown be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of the various system components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that any described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0075] One or more embodiments of the present disclosure may be referred to herein individually and / or collectively by the term "invention", which is merely for convenience and is not intended to actively limit the scope of the present application to any particular invention or inventive concept. In addition, although specific embodiments have been shown and described herein, it should be understood that any subsequent arrangements designed to achieve the same or similar purposes may replace the specific embodiments shown. The present disclosure is intended to cover any and all subsequent modifications or variations of the various embodiments. By reading the specification, the combination of the above-mentioned embodiments and other embodiments not specifically described herein will be apparent to those skilled in the art.

[0076] The Abstract of the present disclosure is provided to comply with 37 CFR §1.72(b) and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of simplifying the disclosure. This disclosure should not be interpreted as reflecting an intention that the claimed embodiments require more features than those expressly recited in each claim. On the contrary, as reflected in the following claims, the inventive subject matter may involve features that are less than all the features of any disclosed embodiment. Therefore, the following claims are incorporated into the Detailed Description, with each claim independently defining a separately claimed subject matter.

[0077] It is intended that the foregoing detailed description be regarded as illustrative rather than restrictive, and it should be understood that the appended claims, including all equivalents, are intended to define the scope of the invention. The claims should not be understood to be limited to the described order or elements unless otherwise stated. Therefore, all embodiments falling within the scope and spirit of the appended claims and their equivalents are claimed to be protected as the present invention.

[0078] Although the embodiments have been described for illustrative purposes, it will be appreciated by those skilled in the art that various modifications, additions and substitutions are possible without departing from the scope and spirit of the present disclosure. Therefore, it is intended that the foregoing description be regarded as illustrative rather than restrictive, and it should be understood that all equivalents and / or combinations of the embodiments and examples are intended to be included in this specification.

[0079] Although certain parts, components, features, and methods of operation have been described herein according to the teachings of the present disclosure, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all embodiments of the teachings of the present disclosure that fully fall within the scope of permissible equivalents.

Claims

1. A bicycle hub, comprising: a driver rotatable about an axis at a first rotational speed, the driver including a mating feature configured to engage the flywheel; a housing including a wheel attachment feature, wherein the housing is rotatable about the axis at a second rotational speed; and A non-adjustable gear train is coupled between the driver and the housing, wherein the non-adjustable gear train defines a single fixed gear ratio between the driver and the housing, wherein the gear ratio is greater than 1:1 such that the second rotational speed is less than the first rotational speed.

2. The bicycle hub according to claim 1, comprising a non-rotatable shaft defining the axis, wherein: The housing and the driver are rotatably supported by the shaft.

3. The bicycle hub according to claim 2, comprising a torque arm non-rotatably engaged with the shaft, wherein: The torque arm includes a frame engaging feature configured to engage a vehicle frame to limit rotation of the axle.

4. The bicycle hub according to claim 2, wherein: The gear train includes a sun gear, a ring gear and a plurality of planet gears, the ring gear surrounds the sun gear, the plurality of planet gears are arranged between the sun gear and the ring gear and mesh with the sun gear and the ring gear, wherein the plurality of planet gears are rotatably mounted on a planet carrier, wherein the ring gear, the planet carrier and one of the sun gear are non-rotatably fixed to the shaft, wherein the planet carrier, the planet carrier and one of the ring gear are connected to the housing and can rotate together with the housing, and wherein the sun gear, the planet carrier and one of the ring gear can engage with the drive and can rotate in at least one rotational direction by the drive.

5. The bicycle hub according to claim 4, wherein: The ring gear is fixed to the shaft, the planet carrier is coupled to the housing and is rotatable therewith, and the sun gear is engageable with the driver and is rotatable by the driver in at least one rotational direction.

6. The bicycle hub according to claim 5, further comprising a ratchet disposed between the sun gear and the driver, wherein: The ratchet is engaged between the driver and the sun gear in a first rotational direction, wherein the sun gear is engaged with the driver in the first rotational direction and can be rotated in the first rotational direction by the driver, and wherein the ratchet is disengaged between the driver and the sun gear in a second rotational direction opposite to the first rotational direction, wherein the sun gear is disengaged from the driver in the second rotational direction and cannot be rotated in the second rotational direction by the driver.

7. The bicycle hub according to claim 6, wherein: The ratchet includes a pawl coupled to one of the driver and the sun gear, wherein the other of the driver and the sun gear includes a plurality of teeth. 8 . The bicycle hub according to claim 7 , further comprising a spring biasing the pawl into engagement with at least one tooth of the plurality of teeth.

9. The bicycle hub according to claim 8, wherein: The pawl is pivotally coupled to the driver and the spring is mounted on the driver, wherein the spring biases the pawl radially outward, and wherein the sun gear includes the plurality of teeth formed around an inner circumferential surface of the sun gear.

10. The bicycle hub according to claim 1, wherein The transmission ratio is between 2:1 and 3:

1.

11. A bicycle transmission system, comprising: A drive unit, the drive unit comprising: a user input component rotatable about a first axis at a first rotational speed; a chain ring rotatable about a second axis at a second rotational speed; and a first gear train coupled between the user input component and the chainring, wherein the first gear train defines a first gear ratio between the user input component and the chainring, wherein the first gear ratio is less than 1:1 such that the second rotational speed is greater than the first rotational speed; A bicycle hub, comprising: a driver rotatable about a third axis at a third rotational speed; a gear coupled to the driver and rotatable with the driver about the third axis at a third rotational speed; a housing including a wheel attachment feature, wherein the housing is rotatable about the third axis at a fourth rotational speed; and a second gear train coupled between the driver and the housing, wherein the second gear train defines a second gear ratio between the driver and the housing, wherein the second gear ratio is greater than 1:1 such that the fourth rotational speed is less than the third rotational speed; and A closed loop component connects the chain ring and the gear.

12. The bicycle transmission system according to claim 11, wherein: The first gear ratio is the reciprocal of the second gear ratio.

13. The bicycle transmission system according to claim 11, wherein: The first axis and the second axis are coaxial.

14. The bicycle transmission system according to claim 11, wherein: The user input component includes a crank connected to a spindle defining the first axis.

15. The bicycle transmission system according to claim 11, wherein: The second gear train includes a planetary gear train.

16. The bicycle transmission system according to claim 15, wherein: The first gear train includes a planetary gear train.

17. The bicycle transmission system according to claim 11, further comprising an output shaft coupled to the chain ring, wherein: The first gear train is coupled between the user input component and the output shaft. 18 . The bicycle drive train according to claim 17 , further comprising a motor coupled to the output shaft.

19. The bicycle transmission train according to claim 18, further comprising a third gear train coupled between the motor and the output shaft.

20. The bicycle transmission system according to claim 19, wherein: The third gear train includes a planetary transmission train.

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