Bicycle derailleur

Abstract

The invention relates to a bicycle gearbox (1000) comprising a housing (1100) comprising two crankshaft openings (1110) for allowing a crankshaft (1600) to pass through the housing. The gearbox further includes a continuously variable transmission (1300) having an input pulley (1310), an output pulley (1330), a V-belt (1320) connecting them, a sprocket (1500) for connection to a chain (the chain being connected to the rear wheel), an input gear, and an output gear. The input gear (1200) is used to connect the crankshaft (1600) to the input pulley (1310) while increasing the rotational speed of the crankshaft (1600) and providing the increased rotational speed to the input pulley (1310). The output gear (1400) is used to connect the output pulley (1330) to the sprocket (1500) while reducing the rotational speed of the output pulley (1330) and providing a reduced rotational speed to the sprocket (1500). In the present invention, an output pulley (1330) is coaxial with a crankshaft (1600).

Description

Technical Field

[0001] This invention relates to a gearbox layout that is compact, lightweight, and provides a functional continuously variable transmission for bicycles, while also allowing integration into the bicycle frame. Background Technology

[0002] For example, document WO 2017103110A1 describes a continuously variable transmission (CVT) based gearbox for bicycles, which is based on two pulleys and a V-belt.

[0003] The known designs face several challenges.

[0004] The pulleys and V-belts of a continuously variable transmission (CVT) are sized to transmit a limited amount of torque (e.g., on the order of 10 Nm) relative to the input torque (e.g., on the order of 200 Nm). This necessitates the use of gears before the CVT to increase its rotational speed relative to the crankshaft. This rotational speed is too high for direct drive to the wheels, thus requiring further gears to reduce the CVT's rotational speed before reaching the wheels.

[0005] Those gears increase the width of the gearbox, so the layout of the components is particularly important for achieving a compact gearbox.

[0006] In addition, bicycle derailleurs must use freewheels. Typical freewheels used in bicycles are heavy because they transmit high torque at low speeds.

[0007] Furthermore, it has been found that if the gearbox housing is made of a thin and lightweight material (such as aluminum) to reduce weight, the gearbox sidewalls can flex under heavy loads. This makes the gearbox noisy and reduces its lifespan because the bearings mounted in the sidewalls are no longer aligned with the corresponding shafts.

[0008] In addition, when gearboxes are used with electric bicycles, there are several ways to better adapt the gearboxes to the specific problems of electric bicycles.

[0009] In particular, e-bikes are known to include torque sensors to provide input to the controller that powers the electric motor. Current torque sensors are often complex axial electromagnetic torque sensors housed in the bottom bracket. Furthermore, if the crank output is supplied to the right sprocket, the force from the right pedal goes directly to the rear wheel without passing through the torque sensor. Therefore, complex algorithms are needed to predict what the right foot will do based on measurements from the left foot. This causes problems, for example, when the rider only pedals the right pedal to begin moving. In this case, the sensor does not receive a load, and the motor therefore provides no power assistance. Similarly, when stopping, if the rider has already pedaled the left pedal and then stops pedaling or even brakes, the motor will continue to apply power for a period of time. These problems impact the usability of e-bikes. Summary of the Invention

[0010] The present invention is defined by claim 1 and has been developed to overcome at least one of the problems pointed out above. The appendices include further features defining more advantageous embodiments.

[0011] Therefore, specific embodiments may relate to a bicycle gearbox, including a housing with two crankshaft openings for allowing the crankshaft to pass through the housing. The bicycle gearbox further includes a continuously variable transmission (CVT) comprising an input pulley, an output pulley, a V-belt connecting the input and output pulleys, and a sprocket for connection to a chain (the chain being connected to the rear wheel). The bicycle gearbox further includes an input gear for connecting the crankshaft to the input pulley, the input gear for increasing the rotational speed of the crankshaft and providing the increased rotational speed to the input pulley. The bicycle gearbox further includes an output gear for connecting the output pulley to the sprocket, the output gear for decreasing the rotational speed of the output pulley and providing the decreased rotational speed to the sprocket. A characteristic of the specific embodiment is that the output pulley is coaxial with the crankshaft.

[0012] In certain embodiments, the input gear can be used to increase the rotational speed of the input pulley by an increasing factor relative to the rotational speed of the crankshaft, wherein the increasing factor can be at least 10, preferably at least 20, more preferably at least 25, and / or wherein the increasing factor can be less than 50, preferably less than 40, more preferably less than 35.

[0013] In certain embodiments, the output gear can be used to reduce the rotational speed of the output pulley by a reducing factor, wherein the reducing factor can be at least 0.01, preferably at least 0.05, more preferably at least 0.1, and / or wherein the reducing factor can be less than 0.3, preferably less than 0.2, more preferably less than 0.15.

[0014] In some specific embodiments, the continuously variable transmission (CVT) may be configured to have a gear range between 1.5 and 10.0, preferably between 1.8 and 4.0.

[0015] In certain specific embodiments, the input gear and the continuously variable transmission can be configured such that, when the gearbox is in use, the input pulley can have an input speed, wherein the input speed can be at least 500 revolutions per minute (RPM), preferably at least 1000 RPM, more preferably at least 1500 RPM, and / or wherein the input speed can be less than 3500 RPM, preferably less than 3000 RPM, more preferably less than 2500 RPM.

[0016] In certain specific embodiments, the output gear and the continuously variable transmission can be configured such that, when the gearbox is in use, the output pulley can have an output speed, wherein the output speed can be at least 500 RPM, preferably at least 700 RPM, and / or wherein the output speed can be less than 4500 RPM, preferably less than 4000 RPM, and / or wherein the output speed can have a range of at least 1000 RPM, preferably at least 2000 RPM, more preferably at least 2500 RPM.

[0017] In certain embodiments, the housing may have its longest dimension along the main extension axis and may be used to connect to the bicycle frame tube, wherein the frame tube may be any of the downtube, chainstay, or other non-standard frame structure, and wherein the housing may be connected to the frame tube such that the frame tube can be positioned parallel to the main extension axis.

[0018] In some specific embodiments, the output gear may be a planetary gear system, including a sun gear, multiple planetary gears, and a ring gear, and the sun gear may be coaxial with the crankshaft.

[0019] In some specific embodiments, the sprocket may be coaxial with the crankshaft.

[0020] In some specific embodiments, the input gear can be a parallel spur gear system.

[0021] In some specific embodiments, the input gear may include a first input gear, a second input gear actuated by the first input gear, a third input gear connected to the second input gear, and a fourth input gear actuated by the third input gear. The second and third input gears may be mounted on a shaft, the longitudinal axis of which may be positioned in the region between the input pulley and the output pulley.

[0022] In some specific embodiments, the bicycle gearbox may further include a freewheel, wherein the input pulley can be used to rotate about the input pulley axle, and wherein the freewheel can be connected between the input pulley axle and the input pulley.

[0023] In some specific embodiments, the input pulley may include a fixed grooved wheel and a sliding grooved wheel, wherein a free wheel may be connected between the input pulley shaft and the fixed grooved wheel.

[0024] In some specific embodiments, the free wheel may be substantially coplanar with the fixed grooved wheel.

[0025] In some specific embodiments, the housing may be split along a first split line into a housing bottom and a housing top, and the housing bottom and housing top may be connected to each other in a separable manner.

[0026] In some specific embodiments, the top of the housing can be used to securely connect to the downtube of the bicycle frame and to the downtube, or to any other non-standard bicycle frame structure.

[0027] In some specific embodiments, the top of the housing can be used for a further robust connection to the rear chainstay of the bicycle frame.

[0028] In some specific embodiments, the crankshaft opening can be implemented at the bottom of the housing.

[0029] In some specific embodiments, the input pulley can rotate about the input pulley axis, the output pulley can rotate about the output pulley axis, and the extensions of both the input pulley axis and the output pulley axis can extend across the side of the bottom of the housing.

[0030] In some specific embodiments, the housing may further include multiple ribs having multiple corresponding holes, and the housing may further include two sides substantially perpendicular to the crankshaft, wherein at least the first of the ribs may be integrated into a corresponding side of the two sides, preferably, the first of the ribs may be substantially perpendicular to the first split line.

[0031] In some specific embodiments, the input pulley can rotate about the input pulley axis, the output pulley can rotate about the output pulley axis, and the first of the ribs can be positioned between the input pulley axis and the output pulley axis.

[0032] In some specific embodiments, at least one of the bottom and top of the housing includes a flange along the first split line.

[0033] In some specific embodiments, the bottom of the outer casing can be split into a first outer casing bottom and a second outer casing bottom along the second split line.

[0034] In some specific embodiments, the output pulley may include a sliding grooved wheel and a fixed grooved wheel. The gearbox may further include a centrifugal actuator for controlling the output pulley according to its rotational speed. The centrifugal actuator includes: a housing; a plate; a plurality of weights placed between the housing and the plate such that, as the output pulley rotates, the weights can be used to push the housing away from the plate; a spring for biasing the sliding grooved wheel toward the fixed grooved wheel to clamp the belt, and wherein the plate is configured such that a radial free volume can exist between the plate and the axis of the output pulley, such that the spring can be positioned within the free volume.

[0035] In some specific embodiments, the bicycle gearbox may further include a force sensor located within the housing, the force sensor comprising: a first connecting portion connected to the housing; a retaining portion for retaining a wheel axle of any one of the continuously variable transmission, input gear, and output gear; and a first strain gauge for measuring the strain between the first connecting portion and the retaining portion.

[0036] In some specific embodiments, the force sensor may further include: a second connecting portion connected to the housing; and a second strain gauge for measuring the strain between the second connecting portion and the retaining portion.

[0037] In some specific embodiments, the retaining part can be used to retain a shaft that rotates faster than the crankshaft.

[0038] Further specific embodiments may relate to a bicycle frame, including a downtube, a chainstay, and a bicycle gearbox of any of the foregoing specific embodiments, wherein the bicycle gearbox can be rigidly connected to at least the downtube and the chainstay.

[0039] In some specific embodiments, the top of the housing may be rigidly connected to at least the downtube and the bottom tube, while the bottom of the housing may be non-rigidly connected to the bicycle frame.

[0040] Further specific embodiments may relate to a bicycle, including a bicycle gearbox according to any of the foregoing specific embodiments, or a bicycle frame according to any of the foregoing specific embodiments. Attached Figure Description

[0041] Figure 1A This is a schematic diagram of a bicycle frame BF, including a bicycle gearbox 1000.

[0042] Figure 1B This is a top view of a bicycle gearbox 1000, with the top of the casing removed.

[0043] Figure 2 This is a partial top view of a bicycle gearbox 2000, in which the top of the housing has been removed and a possible specific embodiment of the input gear 2200 is included.

[0044] Figure 3 This is a partial top view of a bicycle gearbox 3000, in which the top of the housing and the pulley groove wheel 3312 have been removed. Figure 1A A cross-sectional view along line B-B', including possible specific embodiments of the freewheel 3700.

[0045] Figure 4A This is an enlarged schematic diagram of the bicycle gearbox 4000 in the closed state.

[0046] Figure 4B This is an enlarged schematic diagram of the bicycle gearbox 4000 in the open state.

[0047] Figure 4C This is an enlarged schematic diagram of a bicycle gearbox 4000 in the closed state, including possible specific embodiments of the rib 4154.

[0048] Figure 4D This is a top view of the bicycle gearbox 4000 in the open state, with the top of the casing removed.

[0049] Figure 4E For housing 4100 in the open position along Figure 4D A schematic diagram of the cross section of line E-E'.

[0050] Figure 4F This is a cross-sectional schematic diagram of a possible embodiment of the bottom 4120 of the housing.

[0051] Figure 5 This is a cross-sectional schematic diagram of a possible specific embodiment of the centrifugal actuator 5340.

[0052] Figure 6A This is a schematic diagram of a force sensor 6800. Figure 6B This is a schematic diagram showing the possible installation location of the force sensor 6800 in the bicycle gearbox 6000.

[0053] Figure label:

[0054] 1000: Bicycle gearbox

[0055] 1100: Outer casing

[0056] 1110: Crankshaft opening

[0057] 1200: Input gear

[0058] 1300: Continuously Variable Transmission

[0059] 1310: Input pulley

[0060] 1311: Input pulley spring

[0061] 1320: V-belt

[0062] 1330: Output pulley

[0063] 1340: Centrifugal Actuator

[0064] 1400: Output gear

[0065] 1500: Sprocket

[0066] 1600: Crankshaft

[0067] BF: Bicycle frame

[0068] DT: Downpipe

[0069] HT: Head tube

[0070] ST: Bottom tube

[0071] TT: Pipe jacking

[0072] SS: Backhand Fork

[0073] CS: Downward Fork

[0074] EA: Elongation axis

[0075] 2000: Bicycle Gearbox

[0076] 2200: Input gear

[0077] 2210-2240: Gears

[0078] 2250: Shaft

[0079] 2260-2261: Bearings

[0080] 3000: Bicycle gearbox

[0081] 3312: Fixed Grooved Wheel

[0082] 3313: Sliding Grooved Wheel

[0083] 3314: Input pulley shaft

[0084] 3700: Freewheel

[0085] 4000: Bicycle gearbox

[0086] 4100: Casing

[0087] 4110: Crankshaft opening

[0088] 4120: Bottom of the outer casing

[0089] 4121: Bottom of the first outer shell

[0090] 4122: Bottom of the second outer shell

[0091] 41230, 4124: Flange

[0092] 4130: Top of the outer casing

[0093] 4140: First split line

[0094] 4150~4155: Ribs

[0095] 4160~4165: Hole

[0096] 4170, 4171: Side view

[0097] 4170B, 4171B: Side bottom

[0098] 4170T, 4171T: Side and Top

[0099] 4180, 4181: Flange

[0100] 4190: Split line

[0101] 4331: Output pulley axis

[0102] 5332: Fixed Grooved Wheel

[0103] 5333: Sliding Grooved Wheel

[0104] 5340: Centrifugal Actuator

[0105] 5341: Box

[0106] 5342: Plate

[0107] 5343: Heavy object

[0108] 5344: Spring

[0109] 6000: Bicycle gearbox

[0110] 6800: Force Sensor

[0111] 6810: Connecting part

[0112] 6820: Strain Gauge

[0113] 6830: Maintenance section

[0114] 6840: Strain gauge

[0115] 6850: Connecting part Detailed Implementation

[0116] Figure 1AThis is a schematic diagram of a bicycle frame BF including a bicycle gearbox 1000. A top view of the gearbox 1000 with the top of the outer casing removed is shown. Figure 1B .

[0117] As can be seen, the bicycle gearbox 1000 has a housing 1100, which is generally elongated along the main extension axis EA. That is, the housing 1100 has its longest dimension along the main extension axis EA. It will be clear that the main extension axis EA can be positioned in any direction relative to the bicycle frame BF. The housing 1100 is made of a generally elastic material, preferably metal and more preferably aluminum, and is used to connect to the bicycle frame tube, which can be any of the downtube ST, downtube DT, chainstay CS, or other non-standard frame structures.

[0118] The connection between the housing 1100 and the skeleton can be of any known type; however, the housing 1100 is preferably welded to one or more, more preferably two or more, or more preferably three skeleton tubes.

[0119] Preferably, as shown in Figure 1 for the downtube DT, the housing 1100 is used to connect to a given skeleton tube such that the skeleton tube is positioned parallel to the main elongation axis EA. This is particularly advantageous because it allows the housing 1100 to be used as a structural element, replacing at least a portion of the corresponding skeleton tube. In this way, the housing replaces some of the material that would otherwise be present, thus reducing the weight of the bicycle.

[0120] like Figure 1A As can be seen, housing 1100 includes two crankshaft openings 1110, of which only the left opening is visible, but it will be understood that the right opening is symmetrically placed to allow crankshaft 1600 to pass through housing 1100.

[0121] The gearbox 1000 further includes a continuously variable transmission 1300, which itself includes an input pulley 1310, an output pulley 1330, and a V-belt 1320 connecting the input pulley 1310 and the output pulley 1330.

[0122] Sprocket 1500 is available in Figure 1B However, it is not shown for the sake of clarity. Figure 1A It is used to connect to the chain in a manner known per se, and the chain is then connected to the rear wheel.

[0123] Generally, the gearbox 1000 operates as follows: power is transmitted from the crankshaft 1600 to the input pulley 1310 via the input gear 1200 (described later), from the input pulley 1310 to the output pulley 1330 via the V-belt 1320, and from the output pulley 1330 to the sprocket 1500 via the output gear 1400 (also described later). This allows the continuously variable transmission 1300 to operate at speeds different from those of the crankshaft 1600 and / or the sprocket 1500. This is particularly advantageous because the inventors have found that, especially for bicycle applications, the continuously variable transmission 1300 operates better at speeds higher than those normally applied to the crankshaft 1600 and / or the sprocket 1500.

[0124] As noted, the gearbox 1000 includes an input gear 1200, generally used to connect the crankshaft 1600 to the input pulley 1310. In particular, the input gear 1200 is used to increase the rotational speed of the crankshaft 1600 and provide the increased rotational speed to the input pulley 1310. The input gear 1200 is shown schematically only. Figure 1B However, those skilled in the art will understand that they can be implemented in any known manner, for example, using planetary gears, interlocking gears, etc. See later. Figure 2 Let's discuss more specific examples of possible implementations.

[0125] Output gear 1400 is similarly used to connect output pulley 1330 to sprocket 1500, and particularly to reduce the rotational speed of output pulley 1330 and provide a reduced rotational speed to sprocket 1500. The same considerations made for a specific embodiment of input gear 1200 also apply to output gear 1400. In a preferred embodiment, output gear 1400 is implemented as a planetary gear set, with the shaft of its sun gear aligned in a straight line with the shaft of crankshaft 1600.

[0126] Preferably, the input gear 1200 and the output gear 1300 are positioned on opposite sides of the continuously variable transmission 1300. This has been found to allow the gearbox 1000 to have an efficient architecture.

[0127] like Figure 1B As shown, the output pulley 1330 is coaxial with the crankshaft 1600. Those skilled in the art will understand that this can be implemented in several ways. For example, the pulley 1330 can be mounted on a bearing installed on the crankshaft 1600. Alternatively or incidentally, the crankshaft 1600 can be inserted into one or more cylindrical sleeves coaxial with the crankshaft 1600, and the pulley 1330 can be mounted on a bearing installed on one or more sleeves.

[0128] This architecture differs from and is particularly advantageous compared to prior art because it allows for a larger gear range for the input gear 1200 and / or output gear 1400. Furthermore, this architecture is more compact in the width of the pedal crank along the Z-direction, which is a key factor in reducing the Q-coefficient or pedal width for many bicycles. In particular, a narrower Q-coefficient is better for rider efficiency and reduces leg impact.

[0129] More specifically, a preferred embodiment in which the input gear 1200 is implemented as a two-stage spur gear configuration can achieve a wider gear range and a thinner profile than a single planetary gearbox. While a two-stage planetary gearbox may also be used, this would result in a wider range of embodiments for the input gear 1200. As those skilled in the art will understand, the two-stage spur gear configuration can be implemented by two pairs of spur gears, where the output of one pair drives the input of the other pair.

[0130] In a preferred embodiment, the above embodiments allow the speed of the input gears 1200, 2200 relative to the crankshaft 1600 to increase the rotational speed of the input pulley 1310 by an increment factor, which is at least 10, preferably at least 20, and more preferably at least 25. The inventors have found that this increment results in an operating range of the continuously variable transmission 1300 that allows for ideal size and functionality relative to the average crankshaft speed. While the above limitations apply to the minimum value of the increment factor, in some embodiments, the increment factor can also be limited to an upper value. Therefore, in some alternative embodiments, the increment factor can be less than 50, preferably less than 40, and more preferably less than 35.

[0131] Similarly, in a preferred embodiment, the output gear 1400 is used to reduce the rotational speed of the output pulley 1330 by a reduction factor, which may be at least 0.01, preferably at least 0.05, and more preferably at least 0.1. In some alternative embodiments, the reduction factor may be less than 0.3, preferably less than 0.2, and more preferably less than 0.15.

[0132] Those skilled in the art will understand that the increase factor can be defined as:

[0133]

[0134] Furthermore, the reduction coefficient can be defined as:

[0135]

[0136] Furthermore, through extensive testing and experimentation, the inventors have found that a gear range between 1.5 and 10, and preferably between 1.8 and 4, is ideal for the continuously variable transmission 1300. In other specific embodiments, the inventors have found that the gear range is preferably higher than 1.5, more preferably higher than 1.8, and / or preferably lower than 10, more preferably lower than 4. The gear range can be defined as:

[0137]

[0138] Similarly, the inventors have found it particularly advantageous to configure the input gear 1200 and the continuously variable transmission 1300 such that when the gearbox 1000 is in use, the input pulley 1310 has an input speed of at least 500 RPM, preferably at least 1000 RPM, more preferably at least 1500 RPM and / or less than 3500 RPM, preferably less than 3000 RPM, more preferably less than 2500 RPM.

[0139] Similarly, the inventors have found it particularly advantageous to configure the output gear 1400 and the continuously variable transmission 1300 such that, when the gearbox 1000 is in use, the output pulley 1330 has an output speed of at least 500 RPM, preferably at least 700 RPM, and / or less than 4500 RPM, preferably less than 4000 RPM. Alternatively or incidentally, it has been found particularly advantageous to have an output speed in the range of at least 1000 RPM, preferably at least 2000 RPM, and more preferably at least 2500 RPM.

[0140] All the above values ​​are not limiting of the invention. However, they have been found to be particularly effective architectures, resulting in a gearbox 1000 with a smaller size but still operating efficiently.

[0141] As previously described in the preferred embodiment and exemplified by way of example Figure 1B As can be seen, the output gear 1400 can be implemented by a planetary gear system, including a sun gear, multiple planetary gears, and a ring gear. Preferably, the sun gear can be coaxial with the crankshaft 1600. To mount the planetary gear system on the crankshaft 1600 without the planetary gear system rotating with the crankshaft 1600, the same considerations as those for the output pulley 1330 are applied. In particular, the planetary gear system can be separated from the crankshaft 1600 by one or more bearings and / or sleeves if suitable. The input to the output gear 1400 can be the output pulley 1330.

[0142] In a further preferred embodiment, sprocket 1500 may be coaxial with crankshaft 1600. Similarly, the output of output gear 1400 may also be coaxial with crankshaft 1600 and may be connected to sprocket 1500. The same considerations for coaxial mounting on crankshaft also apply to the output of output gear 1400 and / or sprocket 1500.

[0143] This has been found to be particularly advantageous because it allows for coaxial output from the output pulley 1330, which itself can be coaxial with the crankshaft. This allows the chain or belt to be located on the same axis as a typical bicycle, making the gearbox 1000 compatible with existing bicycle frame layouts.

[0144] As described above, in a preferred embodiment, the input gear can be implemented as a non-planetary gear set, preferably as a two-stage spur gear mechanism. One possible embodiment is shown below. Figure 2 .especially, Figure 2 This is a partial top view of a bicycle gearbox 2000, in which the top of the casing has been removed.

[0145] like Figure 2 As can be seen, the input gears 2200 are a parallel spur gear system. That is, they include multiple paddle gears or gears placed parallel to each other. Preferably, the input gears 2200 include a first input gear 2210, a second input gear 2220 actuated by the first input gear 2210, a third input gear 2230 connected to the second input gear 2220, and a fourth input gear 2240 actuated by the third input gear 2230. As noted, this architecture is particularly advantageous because it allows the input gears 1200 to be made thinner than could otherwise be made of comparable planetary gears, resulting in a lower overall size and weight of the gearbox 1000 and a better Q coefficient.

[0146] like Figure 2 As can be seen, the second input gear 2220 and the third input gear 2230 can be mounted on the same shaft 2250, which can be mounted on two bearings 2260 and 2261. As can be seen, the longitudinal axis of the shaft can be positioned in the region between the input pulley 1310 and the output pulley 1330. Alternatively or incidentally, the longitudinal axis of the shaft can be positioned so as not to cross the housing of the centrifugal actuator of the output pulley, for example... Figure 5 The visible box 5341 but Figure 2 Unnumbered.

[0147] This positioning of shaft 2250 is particularly advantageous because it allows for the utilization of space in gearbox 1000 that would otherwise be unused. This is even more advantageous, as it will become clearer from the description of a further preferred embodiment, because the space around shaft 2250 can be used to mount sensors and corresponding electronics and / or cables.

[0148] Figure 3 This is a partial top view of a bicycle gearbox 3000, in which the top of the housing and the pulley groove wheel 3312 have been removed. Figure 1A A cross-sectional view along line B-B', including possible specific embodiments of the freewheel 3700.

[0149] In particular, such as Figure 3 As can be seen, the bicycle gearbox 3000 may further include a freewheel 3700, which is generally mounted on the input pulley 1310 to operate between the input pulley 1310 and the corresponding axis 3314. In this case, the freewheel can have the same function, thus replacing the freewheel that is generally placed in the rear wheel hub of the bicycle.

[0150] In a particular embodiment as illustrated, the input pulley 1310 is rotatable about the input pulley shaft 3314 and includes two pulleys 3312 and 3313. In this particular embodiment, pulley 3312 is fixed relative to the axis 3314, while pulley 3313 is slidable along the axis 3314 and held in place by the action of the input pulley spring 1311 and the V-belts on the pulleys 3312 and 3313. Preferably, as shown, a free wheel 3700 is connected or mounted between the input pulley shaft 3314 and the fixed pulley 3312.

[0151] In this preferred architecture, the freewheel 3700 is connected or mounted between the input pulley shaft 3314 and the input pulley 1310, so that when the torque applied by the input pulley shaft 3314 to the input pulley 1310 is in one direction, the torque is transmitted, and when it is applied in the opposite direction, the torque is not transmitted.

[0152] The placement of the freewheel 3700 between the input pulley shaft 3314 and the input pulley 1310 is particularly advantageous because the torque applied to the freewheel is reduced by the action of the input gear 1200. Since less torque must be transmitted, the freewheel can be made smaller and therefore lighter and cheaper. Furthermore, due to the multiplicative effect of the input gear 1200, the crankshaft backlash caused by the individual clearance of the freewheel 3700 can be significantly reduced compared to prior art, thus resulting in less clearance on the pedal when the user pedals.

[0153] Furthermore, such as Figure 3 As can be seen, the freewheel 3700 can be substantially coplanar with the Geneva wheel to which it is connected (for example, the fixed Geneva wheel 3312). In this way, the dimension along the Z direction of the gearbox remains small.

[0154] In the specific embodiments described so far, housing 1100 has been generally described as enclosing gearbox 1000. As those skilled in the art will appreciate, this can be implemented in several ways, for example, housing components can be manufactured separately and then assembled together in various ways.

[0155] Figures 4A-4F This is a schematic diagram of a specific possible embodiment of the housing 4100.

[0156] especially, Figure 4A This is an enlarged diagram of a bicycle gearbox 4000 in the closed state. The same gearbox 4000... Figure 4B It is displayed as enabled. Figure 4C An enlarged schematic diagram of a bicycle gearbox 4000 in the closed state, including optional ribs 4154. Figure 4D This is a top view of the bicycle gearbox 4000 in the open state, with the top of the casing removed.

[0157] Figure 4E and 4F For housing 4100 in the open position along Figure 4D An alternative embodiment of the cross-sectional schematic diagram of line E-E'.

[0158] like Figure 4A and 4B As can be seen, the outer shell 4100 is split into a bottom shell 4120 and a top shell 4130 along the first split line 4140, such that the bottom shell 4120 and the top shell 4130 are connected to each other in a separable manner.

[0159] In a preferred embodiment, the bottom of the housing 4120 is larger than the top of the housing 4130. Preferably, the bottom of the housing 4120 is used for most (preferably all) of the components containing the gearbox 4000, and the top of the housing 4130 can act as a cover to close the bottom of the housing 4120.

[0160] This architecture is particularly advantageous because the separation of the bottom and top of the housing allows the top of the housing 4130 to be structurally connected to the bicycle's frame, while the bottom of the housing 4120 can be opened to assemble and / or repair the gearbox assembly. In particular, by removing the top of the housing 4130, the bottom of the housing 4120 can become open at its top, thus providing easy access to the derailleur assembly. This contrasts with some existing solutions that remove the top of the housing (for example, in the form of a bracket) without providing access to the components inside the housing.

[0161] By simply disconnecting the top of the housing from the bottom of the housing 4120, it is advantageous to be able to easily repair the components inside the housing.

[0162] Alternatively, in a preferred embodiment, most of the components contained in the housing 4100 (in some more preferred embodiments, all of the components) can be held in place and / or structurally connected to the housing bottom 4120 via the housing bottom 4120.

[0163] In this way, the top of the housing 4130 can be shipped to the frame manufacturer for connection to the frame, while the bottom of the housing 4120 can be shipped to the bicycle manufacturer along with the components installed in the gearbox. The bicycle manufacturer can then receive the frame with the top of the housing 4130 mounted on it, thus easily installing the previously assembled gearbox by simply connecting the top of the housing 4130 to the bottom of the housing 4120.

[0164] Furthermore, this approach allows the top of the housing 4130 to have a specific design and / or brackets for connection to the frame, while maintaining a limited number of designs for the bottom of the housing 4120, preferably a single design. In this way, the gearbox can be adapted to multiple frames while maintaining a single design for most of the gearbox components, preferably all components of the gearbox except for the top of the housing 4130.

[0165] Preferably, housing 4100 includes two sides 4170, 4171 substantially perpendicular to crankshaft 1600. The sides are preferably substantially parallel to each other and preferably extend substantially along the elongation axis EA. Split lines are used to divide housing 4100 across sides 4170, 4171, resulting in side bottoms 4170B, 4171B and side tops 4170T, 4171T.

[0166] By splitting the housing in this way, the top of the housing 4130 no longer contains further split lines, and therefore can be used for reliable connection to the bicycle frame (preferably by welding). In the preferred embodiment shown, the top of the housing 4130 can therefore be used for robust connection to the downtube ST of the bicycle frame BF and to the downtube DT, or to any other non-standard bicycle frame structure.

[0167] This embodiment advantageously allows the top housing 4130 to be welded into the frame assembly. The bottom housing 4120, containing the transmission assembly, can then be easily assembled to the top housing 4130, for example, by screws or other connecting means.

[0168] Preferably, in some specific embodiments, the top of the housing 4130 is used for further robust connection to the rear chainstay CS of the bicycle frame BF.

[0169] By connecting the top of the outer casing to more than one skeleton tube, the outer casing 4100 can also act as a structural element of the skeleton to reduce the total weight of the skeleton.

[0170] like Figure 4C As can be seen, the split line 4140 is used to allow the crankshaft opening 4110 to be realized in the bottom of the housing 4120. In other words, the crankshaft opening 4110 is realized in the side bottoms 4170B, 4171B. This allows for precise assembly of the crankshaft and bearings, and generally all gearbox parts, because turning and assembly can be performed without involving the top of the housing 4130. The bottom of the housing can then be pre-assembled and shipped to the bicycle manufacturer for connection to the frame.

[0171] More preferably, in certain embodiments, the input pulley 1310 is rotatable on the input pulley shaft 3314, and the output pulley 1330 is rotatable on the output pulley shaft 4331. The extensions of both the input pulley shaft 3314 and the output pulley shaft 4331 extend across the sides 4170, 4171 of the bottom of the housing 4120, i.e., the bottom sides 4170B, 4171B.

[0172] Regarding the crankshaft opening, this allows for easy assembly of various components, such as bearings for the input pulley shaft 3314 and the output pulley shaft 4331, and also allows for easy manufacturing.

[0173] In certain specific embodiments, for example, Figure 4C and 4D As can be seen, the housing 4100 may include a plurality of ribs 4150-4155 having a plurality of corresponding holes 4160-4165, wherein at least the first rib 4151, 4154 of the ribs 4150-4155 is integrated into a corresponding one of the sides 4170, 4171.

[0174] As those skilled in the art will understand, the multiple ribs 4150-4155 can be implemented by thickening the material in the corresponding sides 4170, 4171. Preferably, the ribs 4150-4155 are elongated, and the holes 4160-4165 can be implemented with a longitudinal extension substantially parallel to the longitudinal extension of the ribs. The ribs are preferably implemented on the outside of the housing, so that corresponding screws can be inserted into the holes as a means of connection between the top and bottom of the housing.

[0175] Preferably, one or more of the ribs 4151-4155 are substantially perpendicular to the first split line 4140. In this way, in addition to thickening the housing to achieve the holes, the ribs can also result in increased strength of the housing, which prevents the housing from deflecting under load, keeps the bearings and shafts aligned, and prevents wear and noise in the gearbox.

[0176] As previously described, input pulley 1310 is for rotation on input pulley shaft 3314 and output pulley 1330 is for rotation on output pulley shaft 4331. At least one of ribs 4150-4155 is positioned between input pulley shaft 3314 and output pulley shaft 4331, relative to those reference members. This position along the elongation axis EA (and therefore approximately in the middle of surfaces 4170, 4171) is particularly advantageous because it provides strength at the location where deflection is most likely under load.

[0177] As those skilled in the art will understand, the interface between the bottom and top of the housing can be implemented in various ways. However, as Figure 4E and 4F As can be seen, in a particularly advantageous embodiment, at least one of the housing bottom 4120 and housing top 4130 may include flanges 4180, 4181 along the first split line 4140.

[0178] This embodiment is particularly advantageous because it helps reduce housing deflection under load, thus avoiding wear and noise. Furthermore, the flange is an ideal surface for placing gaskets, ensuring the interior of the housing is environmentally closed.

[0179] Although the outer casing of the above specific embodiment has only one split line, the present invention is not limited to this embodiment. In particular, as Figure 4F As can be seen, the bottom of the outer casing 4120 can be further divided into a first bottom of the outer casing 4121 and a second bottom of the outer casing 4122 along the second split line 4190. The second split line 4190 can be interposed by a plane substantially perpendicular to the plane interposed by the first split line 4140. In other words, the second split line can extend along the elongation axis EA of the outer casing, but along the bottom surface substantially perpendicular to the sides 4170, 4171.

[0180] The second split line 4190 simplifies the assembly of the gearbox assembly within the housing bottom 4120, as the assembly can be positioned on one of the first or second housing bottoms, and then the first and second housing bottoms can be abutted together. As those skilled in the art will appreciate, the first and second housing bottoms can be secured together in various ways, for example, by ribs similar to those previously described with respect to the first split line 4140. Furthermore, as Figure 4F As can be seen, flanges 4180 and 4181 can also be implemented along the second split line 4190.

[0181] In the above specific embodiments, the operation of the continuously variable transmission has only been described in general terms, particularly regarding how to control the output pulley 1330.

[0182] The commonly known method for controlling the opening of the output pulley is to use a centrifugal actuator. Figure 5This is a schematic cross-sectional view of a possible specific embodiment of such a centrifugal actuator, in the form of centrifugal actuator 5340.

[0183] In particular, such as Figure 5 As can be seen, the output pulley 1330 may include: a sliding grooved wheel 5333; a fixed grooved wheel 5332; and a centrifugal actuator 5340 for controlling the output pulley 1330 according to its rotational speed. In particular, the centrifugal actuator 5340 may generally be used to control the sliding grooved wheel 5333 to move away from the fixed grooved wheel 5332 as the rotational speed of the output pulley 1330 decreases, and conversely, to move the sliding grooved wheel 5333 toward the fixed grooved wheel 5332 as the rotational speed of the output pulley 1330 decreases.

[0184] like Figure 5 As can be seen, the centrifugal actuator 5340 includes: a housing 5341; a plate 5342; and a plurality of weights 5443 placed between the housing 5341 and the plate 5342, such that as the output pulley 1330 rotates, the weights are used to push the housing 5341 away from the plate 5342. The centrifugal actuator 5340 further includes a spring 5344 for pressing the sliding pulley 5333 against the fixed pulley 5332 to clamp the belt. The spring can do this by compressing the sliding pulley 5333 on the side opposite to the fixed pulley 5332 between the plate 5342 and the sliding pulley 5333. The plate 5342 can be advantageously configured such that there is a radial free volume between the plate 5342 and the output pulley axis 4331, such that the spring 5344 can be positioned within the free volume.

[0185] It will be understood that this can be implemented in many ways, and the specific embodiments shown are only one possible particular embodiment.

[0186] Generally, the plate may have an inclined surface on which the weight 5433 can slide or roll. This sliding surface may be connected to a surface facing the axis that is substantially parallel to the axis 4331, such that a space exists between this surface and the axis 4331. The plate may also have a connecting surface that connects the surface facing the axis to the axis 4331. Preferably, the connecting surface is substantially perpendicular to the surface facing the axis and / or perpendicular to the axis 4331. More preferably, the connecting surface may be connected to one end of the surface facing the axis, while the other end of the surface facing the axis may be connected to the inclined surface.

[0187] Regardless of the specific embodiment, the centrifugal actuator can therefore be configured such that the spring 5433 is substantially positioned in the same area of ​​the ramp and / or the weight 5343 along the direction of axis 4331. This contrasts with known prior art, where the spring is often placed below the area of ​​the ramp in the Z direction of the figure, resulting in a larger housing width in the Z direction.

[0188] The gearbox of this invention is particularly well-suited for electric bicycle applications. This is because the continuously variable transmission 1300 can operate at a particularly high torque, thanks to the increased rotational speed which reduces the torque applied to it.

[0189] Electric bicycles typically require sensors to indicate the force applied by the cyclist on the pedals, which can then be used to control the electric motor. Such sensors were previously known to be placed in the pedals and / or cranks. However, both placements present various problems.

[0190] As will become clearer from the following description, those problems can be solved by placing the force sensor inside the gearbox. Figure 6A This is a schematic diagram of a force sensor 6800. Figure 6B This is a schematic diagram showing the possible installation location of the force sensor 6800 in the bicycle gearbox 6000.

[0191] In particular, such as Figure 6A As can be seen, the force sensor 6800 may include a first connecting portion 6810 for connecting the force sensor to the housing. The connection can be made in a known manner, for example, by means of a screw.

[0192] The force sensor 6800 may further include a retaining portion 6830 for retaining the shaft of any one of the continuously variable transmission 1300, input gears 1200 and 2200, and output gear 1400. The retaining method may take any form known in the art, such as by providing mounting points in the retaining portion 6830 for retaining the component to be retained. For example, the retaining portion 6830 may be used to support a bearing that holds a given axis in place.

[0193] The force sensor 6800 may further include a first strain gauge 6820 for measuring the strain between the first connecting portion 6810 and the holding portion 6830.

[0194] Thanks to this embodiment, under load, a given torque will be applied to either axis of the gearbox and can be measured by a strain gauge. However, compared to prior art, because the strain gauge can measure the load on the gearbox's transmission independently of the applied pedal, the e-bike can provide an improved rider experience by applying power assistance based directly on the load from each pedal stroke. Furthermore, this strain gauge design is cheaper to develop, manufacture, and control, and is less sensitive to tolerances than other sensor types (such as electromagnetic torque sensors or externally mounted sensors), which require protective components and are easily damaged.

[0195] At Figure 6AIn the specific embodiment shown, the force sensor further includes: a second connecting portion 6850 connected to the housing; and a second strain gauge 6840 for measuring the strain between the second connecting portion 6850 and the holding portion 6830. The same considerations made for the first element apply to the corresponding second element.

[0196] This embodiment is particularly advantageous because it allows for compensation for temperature variations. In particular, the two strain gauges can be mounted in opposite directions relative to the retainer, thus canceling out any differences in material expansion between the sensor and the bracket.

[0197] Note that although Figure 6A The force sensor forms an angle between a first direction connecting the first connecting portion 6810 and the holding portion 6830 and a second direction connecting the second connecting portion 6850 and the holding portion 6830, but the invention is not limited thereto. In principle, the sensor can have any shape.

[0198] However, it has been found that the angle between the first and second directions best counteracts the force applied to the retaining portion 6830 and provides a more stable retaining feature, resulting in less noise and wear. In a preferred embodiment, the angle between the first and second directions is preferably between 30 and 60 degrees.

[0199] In a preferred embodiment, the retaining part 6830 is preferably used to retain the shaft of the input gears 1200, 2200 that rotates faster than the crankshaft 1600. Because this shaft rotates faster than the pedal crank, a higher resolution data output is obtained from a sensor of the same quality as the pedal crank.

[0200] For example, Figure 6B This is a schematic diagram of a possible mounting location for the force sensor. In this particular embodiment, the force sensor is used to hold one end of axis 2250 by means of a corresponding bearing mounted within the force sensor.

[0201] Preferably, any rotating axis within the gearbox can be used for sensing by a sensor. However, in a more preferred embodiment, the sensor is preferably mounted on an axis in the direction of torque transmission from the pedal to the wheel and prior to the flywheel, so as to ensure that the pedal is constantly monitored and to avoid feeling rear pressure from the rear wheels of the continuously variable transmission (CVT).

[0202] Although the above-described specific embodiments mainly relate to gearboxes, it will be clear that the present invention can also be implemented as a bicycle frame (BF in the figure) including downtube ST, downtube DT, chainstay CS, and any of the above-described bicycle gearboxes.

[0203] Preferably, the gearbox is rigidly connected to at least the downtube ST and downtube DT. This is considered particularly advantageous because it provides ideal positioning for the crankcase and allows the gearbox to become an integrated part of the frame, thus avoiding the weight of the frame's bottom bracket.

[0204] In a preferred embodiment where the housing is split into a top housing and a bottom housing, the top housing 4130 is preferably rigidly connected to at least the downtube ST and the downtube DT, while the bottom housing 4120 is preferably not rigidly connected to the bicycle frame BF.

[0205] Specific embodiments of the present invention may also relate to bicycles including any of the above-described bicycle gearboxes or bicycle frames (BF).

Claims

1. A bicycle gearbox (1000~6000), comprising: The housing (1100, 2100, 4100) includes two crankshaft openings (1110, 2110, 4110) for allowing the crankshaft (1600) to pass through the housing (1100, 2100, 4100). The continuously variable transmission (CVT) (1300) includes an input pulley (1310), an output pulley (1330), and a V-belt (1320) connecting the input pulley (1310) and the output pulley (1330). A sprocket (1500) is used to connect to a chain, wherein the chain is connected to the rear wheel. Input gears (1200, 2200) are used to connect the crankshaft (1600) to the input pulley (1310), wherein the input gears (1200, 2200) are used to increase the rotational speed of the crankshaft (1600) and provide the increased rotational speed to the input pulley (1310). An output gear (1400) is used to connect the output pulley (1330) to the sprocket (1500), wherein the output gear (1400) is used to reduce the rotational speed of the output pulley (1330) and provide the reduced rotational speed to the sprocket (1500). Its features are, The output pulley (1330) is coaxial with the crankshaft (1600).

2. The bicycle gearbox (1000~6000) according to claim 1, characterized in that, The input gears (1200, 2200) are used to increase the rotational speed of the input pulley (1310) relative to the rotational speed of the crankshaft (1600) by an increasing factor. Wherein, the increase coefficient is at least 10, preferably at least 20, more preferably at least 25, and / or Wherein, the increase coefficient is less than 50, preferably less than 40, and even more preferably less than 35.

3. The bicycle gearbox (1000~6000) according to any one of the preceding claims, characterized in that, The output gear (1400) is used to reduce the rotational speed of the output pulley (1330) by a reduction factor. Wherein, the reduction coefficient is at least 0.01, preferably at least 0.05, more preferably at least 0.1, and / or Wherein, the reduction coefficient is less than 0.3, preferably less than 0.2, and even more preferably less than 0.

15.

4. The bicycle gearbox (1000-6000) according to any one of the preceding claims, characterized in that, The continuously variable transmission (1300) is configured to have a gear range between 1.5 and 10, preferably between 1.8 and 4.

5. The bicycle gearbox (1000-6000) according to any one of the preceding claims, characterized in that, The input gears (1200, 2200) and the continuously variable transmission (1300) are configured such that when the gearbox (1000~6000) is in use, the input pulley (1310) has an input speed. Wherein, the input speed is at least 500 revolutions per minute, preferably at least 1000 revolutions per minute, more preferably at least 1500 revolutions per minute, and / or The input speed is less than 3500 revolutions per minute, preferably less than 3000 revolutions per minute, and even more preferably less than 2500 revolutions per minute.

6. The bicycle gearbox (1000~6000) according to any one of the preceding claims, characterized in that: The output gear (1400) and the continuously variable transmission (1300) are configured such that when the gearbox (1000~6000) is in use, the output pulley (1330) has an output speed. Wherein, the output speed is at least 500 revolutions per minute, preferably at least 700 revolutions per minute, and / or Wherein, the output speed is less than 4500 revolutions per minute, preferably less than 4000 revolutions per minute, and / or The output speed has a range of at least 1,000 revolutions per minute, preferably at least 2,000 revolutions per minute, and more preferably at least 2,500 revolutions per minute.

7. The bicycle gearbox (1000-6000) according to any one of the preceding claims, characterized in that, The outer casings (1100, 2100, 4100) have the longest dimension along the main elongation axis (EA) and are used to connect to the bicycle's frame tubes. The skeleton tube can be any one of the bottom tube (ST), bottom tube (DT), and rear bottom runner (CS), or other non-standard skeleton structures. The outer shell (1100, 2100, 4100) is used to connect to the skeleton tube, such that the skeleton tube is positioned parallel to the main elongation axis (EA).

8. The bicycle gearbox (1000-6000) according to any one of the preceding claims, characterized in that, The output gear (1400) is a planetary gear system, which includes a sun gear, multiple planetary gears, and a ring gear. The sun gear is coaxial with the crankshaft (1600).

9. The bicycle gearbox (1000-6000) according to any one of the preceding claims, characterized in that, The sprocket (1500) is coaxial with the crankshaft (1600).

10. The bicycle gearbox (1000-6000) according to any one of the preceding claims, characterized in that, The input gears (1200, 2200) are a parallel spur gear system.

11. The bicycle gearbox (2000) according to any one of the preceding claims, characterized in that, The input gear (2200) includes a first input gear (2210), a second input gear (2220) actuated by the first input gear (2210), a third input gear (2230) connected to the second input gear (2220), and a fourth input gear (2240) actuated by the third input gear (2230). The second input gear (2220) and the third input gear (2230) are mounted on the shaft (2250). The longitudinal axis of the shaft (2250) is located in the region between the input pulley (1310) and the output pulley (1330).

12. The bicycle gearbox (3000) according to any one of the preceding claims, characterized in that, Further includes the Freewheel (3700). The input pulley (1310) is used to rotate about the input pulley shaft (3314). The free wheel (3700) is connected between the input pulley shaft (3314) and the input pulley (1310).

13. The bicycle gearbox (3000) according to claim 12, characterized in that, The input pulley (1310) includes a fixed grooved wheel (3312) and a sliding grooved wheel (3313). The free wheel (3700) is connected between the input pulley shaft (3314) and the fixed grooved wheel (3312).

14. The bicycle gearbox (3000) according to claim 13, characterized in that, The free wheel (3700) is substantially coplanar with the fixed grooved wheel (3312).

15. The bicycle gearbox (4000) according to any one of the preceding claims, characterized in that, The outer shell (4100) is split along the first split line (4140) into a bottom shell (4120) and a top shell (4130), and The bottom (4120) and top (4130) of the housing are detachably connected to each other.

16. The bicycle gearbox (4000) according to claim 15, characterized in that, The top of the housing (4130) is used to securely connect to the downtube (ST) and downtube (DT) of the bicycle frame (BF), or to any other non-standard bicycle frame architecture.

17. The bicycle gearbox (4000) according to claim 16, characterized in that, The top of the outer shell (4130) is used for further robust connection to the rear chainstay (CS) of the bicycle frame (BF).

18. The bicycle gearbox (4000) according to any one of claims 15 to 17, characterized in that, The crankshaft opening (4110) is located at the bottom of the housing (4120).

19. The bicycle gearbox (4000) according to any one of claims 15 to 18, characterized in that: The input pulley (1310) is used to rotate about the input pulley shaft (3314); The output pulley (1330) is used to rotate about the output pulley axis (4331); The extensions of the input pulley shaft (3314) and the output pulley shaft (4331) both extend across the side (4170) of the bottom (4120) of the housing.

20. The bicycle gearbox (4000) according to any one of claims 15 to 19, characterized in that: The outer casing (4100) further includes multiple ribs (4150-4155) having corresponding multiple holes (4160-4165). The housing (4100) further includes two sides (4170, 4171) that are substantially perpendicular to the crankshaft (1600). Wherein, at least the first rib (4151, 4154) of the ribs (4150~4155) is integrated into a corresponding side of the two sides (4170, 4171). Preferably, the first rib (4151, 4154) of the ribs (4150~4155) is substantially perpendicular to the first split line (4140).

21. The bicycle gearbox (4000) according to claim 20, characterized in that: The input pulley (1310) is used to rotate about the input pulley shaft (3314). The output pulley (1330) is used to rotate about the output pulley axis (4331). The first rib (4151, 4154) of the ribs (4150~4155) is positioned between the input pulley shaft (3314) and the output pulley shaft (4331).

22. The bicycle gearbox (4000) according to any one of claims 15 to 21, characterized in that, At least one of the bottom (4120) and top (4130) of the housing includes a flange (4180, 4181) along the first split line (4140).

23. The bicycle gearbox (4000) according to any one of claims 15 to 22, characterized in that, The bottom of the outer shell (4120) is split into a first bottom shell (4121) and a second bottom shell (4122) along the second split line (4140).

24. The bicycle gearbox (1000~6000) according to any one of the preceding claims, characterized in that, The output pulley (1330) includes a sliding grooved wheel (5333) and a fixed grooved wheel (5332), and the gearbox further includes a centrifugal actuator (5340) for controlling the output pulley (1330) according to the rotational speed of the output pulley (1330), wherein the centrifugal actuator (5340) includes: Box (5341) Part (5342) Multiple weights (5443) are placed between the housing (5341) and the plate (5342) such that as the output pulley (1330) rotates, the weights are used to push the housing (5341) away from the plate (5342). A spring (5344) is used to bias the sliding pulley (5333) toward the fixed pulley (5332) to clamp the belt. The plate (5342) is configured such that there is a radial free volume between the plate (5342) and the output pulley axis (4331) so that the spring (5344) can be positioned in the free volume.

25. The bicycle gearbox (6000) according to any one of the preceding claims, characterized in that, The system further includes a force sensor (6800) located within the housings (1100, 2100, 4100), wherein the force sensor comprises: The first connecting part (6810) is connected to the outer casing (1100, 2100, 4100). The retaining part (6830) is used to retain one shaft of any one of the continuously variable transmission (1300), input gears (1200, 2200), and output gear (1400). A first strain gauge (6820) is used to measure the strain between the first connecting part (6810) and the retaining part (6830).

26. The bicycle gearbox (6000) according to claim 24, characterized in that, The force sensor further includes: a second connecting part (6850) connected to the housing (1100, 2100, 4100); and a second strain gauge (6840) for measuring the strain between the second connecting part (6850) and the retaining part (6830).

27. The bicycle gearbox (6000) according to claim 25 or 26, characterized in that, The retaining part (6830) is used to retain the input gears (1200, 2200) so that they rotate faster than the crankshaft (1600).

28. A bicycle frame (BF), characterized in that, include: Downtube (ST), downtube (DT), and rear chainstay (CS), and The bicycle gearbox (1000~6000) according to any of the preceding claims. The bicycle gearbox (1000~6000) is rigidly connected to at least the downtube (ST) and the downtube (DT).

29. The bicycle frame (BF) according to claims 28 and 15, characterized in that: The top of the housing (4130) is securely connected to at least the lower tube (ST) and the lower tube (DT). The bottom of the outer shell (4120) is not rigidly attached to the bicycle frame (BF).

30. A bicycle, characterized in that, Includes a bicycle gearbox (1000-6000) according to any one of claims 1 to 27, or includes a bicycle frame (BF) according to claim 28 or 29.

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