Continuously variable transmission for bicycle

Abstract

A continuously variable transmission for a bicycle is provided that improves the functionality of the bicycle and increases the reliability and life of the transmission. The transmission is continuously variable between possible infinite number of speed ratios, allowing a user to select an appropriate speed ratio based on operating conditions, riding of the bicycle, and any other consideration of the user. The driver assembly reduces torque from the crankshaft to a set of sheaves and belts to improve reliability and life of components of the transmission that set the speed ratio. In addition, the position motor simply and accurately controls the speed ratio by controlling the relative position between the sheaves. The driven assembly increases the torque output to a driving wheel that propels the bicycle.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 421,031, filed on October 31, 2022, the entire content of which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a continuously variable transmission, particularly for a bicycle, which transmits power from a crankshaft to a rear hub through a potentially infinite number of speed ratios. Background Art

[0004] Some prior - art bicycles have a chain that connects a single sprocket at the crankshaft and a single sprocket at the rear hub to transmit power from the rider's pedaling motion at the crankshaft to the rear wheel at the rear hub, which propels the bicycle. However, with one sprocket at the crankshaft and one sprocket at the rear hub, the bicycle has only a single gear ratio to transmit power to the rear wheel at the rear hub. This gear ratio can be optimized for a narrow range of operating conditions of the bicycle, but not for a wide range of operating conditions. For example, the gear ratio can be a high gear ratio, where the sprocket at the rear hub has relatively more teeth, which provides increased torque to move the bicycle from a stationary position, but limits the rider's ability to achieve high speeds on the bicycle. Conversely, the gear ratio can be a low gear ratio, where the sprocket at the rear hub has relatively fewer teeth, allowing for increased speed, but limiting the user's ability to initially propel the bicycle from a stationary position.

[0005] To address this problem, other prior - art bicycles have multiple sprockets at the crankshaft and / or multiple sprockets at the rear hub to provide multiple possible gear ratios between the crankshaft and the rear hub. Thus, when the bicycle is stationary, the rider can start in a high gear ratio to provide greater torque and help propel the bicycle from a stationary position. Then, a derailleur can move the chain connecting the crankshaft and the rear hub from one sprocket at the crankshaft or the rear hub to another sprocket to establish a low gear ratio. As a result, the rider can further increase the speed of the bicycle, which is similar to a conventional automobile gradually increasing speed by shifting gears during acceleration. However, even with multiple gears, the rider can only select between a limited number of gear ratios. These few gear ratios are optimized for certain operating conditions, which may not be suitable for a particular rider. Additionally, the multiple sprockets, derailleurs, and other shifting components increase the complexity, weight, and more potential failure points of the bicycle.

[0006] Another prior art system includes multiple spur or helical gears located at the crankshaft. The operation of the gear system is similar to that of an automotive transmission and requires a complex shifter to change the gear ratio. Like the sprocket and derailleur described above, this gear system allows the user to change between a limited number of gear ratios, and these systems are complex, bulky, and expensive.

[0007] Compared with the sprocket and derailleur system and the gear system at the crankshaft, embodiments of the present disclosure do not rely on sprockets or gears for a limited number of gear ratios. Instead, the embodiments described herein have multiple sets of grooved pulleys connected by a belt, and the belt continuously moves between a potentially infinite number of speed ratios, which allows the user to specifically select an appropriate speed ratio for the current operating conditions. "Speed ratio" describes the relative mechanical advantage between multiple sets of grooved pulleys and is similar to the gear ratio.

[0008] Other prior art systems for transmitting power can be located at the rear hub of a bicycle. One such system has planetary gears inside the rear hub, and the planetary gears rely on a precise shifter to change the gear ratio, and the shifter requires the bicycle to be moving and coasting without input power in order to change the gear ratio. As described herein, embodiments of the present disclosure have a position motor that precisely controls the speed ratio. In addition, the position motor can control the speed ratio and maintain a specific speed ratio during operation.

[0009] Another prior art system located at the rear hub uses a continuously variable mechanism with a rotating ball ring to continuously change the gear ratio or speed ratio between the input and output ends of the system. However, this system requires special traction fluid, has high internal forces that reduce the reliability and lifespan of the system, and is bulky, inefficient, and expensive. Embodiments of the present disclosure provide a continuously variable transmission that does not require special fluid and reduces internal forces to improve the reliability and lifespan of the transmission. Specifically, the drive assembly described herein increases the rotational speed of the grooved pulleys and the belt to reduce the torque borne by these components, which reduces wear and tear and increases the reliability and lifespan of the transmission. Summary of the Invention

[0010] Embodiments of the present disclosure relate to a novel transmission that allows for continuously changing the speed ratio between an input crankshaft and an output drive wheel between a potentially infinite number of speed ratios. In addition, embodiments of the present disclosure more precisely control the speed ratio and are more reliable and durable. Many of the embodiments described herein relate to a transmission for a bicycle, but the transmission according to the present disclosure can be applied to any small human-powered vehicle or electric vehicle with a transmission.

[0011] One aspect of various embodiments of the present disclosure is to provide a continuously variable transmission having a sheave set and a belt to provide stepless change between a potentially infinite number of speed ratios, which allows a user to control the speed ratio for specific operating conditions of a bicycle. A set of sheaves is positioned around a crankshaft rotatable about a crankshaft axis, and another set of sheaves is positioned around a countershaft rotatable about a countershaft axis parallel to the crankshaft axis. Power is transmitted via the belt from a set of sheaves or drive sheaves around the crankshaft to a set of sheaves or driven sheaves around the countershaft. Each set of sheaves has a fixed sheave that rotates around the axis but does not move along the axis, and each set of sheaves has a movable sheave that rotates around the axis and moves along the axis.

[0012] To change the speed ratio between the sheave sets and the speed ratio of the entire transmission, one of the movable sheaves changes position along its corresponding axis. For example, if the movable driven sheave moves closer to the fixed driven sheave, the belt moves to contact the inner surface of the driven sheave away from the countershaft axis. The movable drive sheave moves to accommodate the change in position of the belt, and this establishes a high speed ratio. Conversely, if the movable driven sheave moves away from the fixed driven sheave, the belt moves and contacts the inner surface of the driven sheave closer to the countershaft axis. Similarly, the movable drive sheave moves to accommodate the change in position of the belt, and this establishes a low speed ratio. A biasing member acting on the movable drive sheave accommodates these changes in speed ratio, as described in further detail herein.

[0013] One aspect of embodiments of the present disclosure is to provide a position motor to simply and precisely control the position of the movable driven sheave along the countershaft axis to establish the speed ratio of the transmission. For example, the position motor can be a servo motor with an output shaft rotatable about an axis. In various embodiments, an eccentric cam is connected to the output shaft, and a hub is connected to the movable driven sheave. The eccentric cam is positioned in a groove of the hub such that when the output shaft and the eccentric cam rotate, the hub and the movable driven sheave move along the countershaft axis to establish the speed ratio. Thus, the position motor can change the speed ratio and maintain a desired speed ratio within a range of bicycle speeds and input powers. Additionally, the position motor can change the speed ratio when the bicycle is stationary or moving and / or when the user pedals to provide power to the transmission or when simply coasting.

[0014] Another aspect of some embodiments of the present disclosure is to reduce the torque acting on the sprocket and the belt to increase the reliability and lifespan of the transmission. Generally, force or torque is inversely proportional to speed in a transmission, where an increase in torque is associated with a decrease in speed, and a decrease in torque is associated with an increase in speed. High torque on the sprocket and belt will shorten the lifespan of these components. Additionally, high torque on the sprocket may damage the positioning motor or other components. Therefore, the speed is increased to reduce the torque at the sprocket and the belt. The drive assembly transmits torque from the crankshaft to the drive sprocket, and the drive assembly increases the rotational speed of the sprocket compared to the crankshaft while reducing the torque, which increases the reliability and lifespan of the transmission.

[0015] The drive assembly can be arranged to accommodate various constraints of a bicycle. For example, an embodiment of the transmission can be located at the bottom bracket of a bicycle frame where the user engages the pedals and the crankshaft, and some components of the transmission are positioned around the crankshaft. Therefore, some components of the transmission are subject to certain dimensional constraints, such as the distance between the crank arms that couple the pedals to the crankshaft and the clearance distance of the bottom bracket above the ground. Thus, in various embodiments, the drive assembly includes two planetary gear sets connected in series to transmit power from the crankshaft to the drive sprocket. In these embodiments, the drive assembly can be referred to as a drive gear assembly. The use of two planetary gear sets satisfies the necessary torque reduction while maintaining the form factor of the transmission compact enough. However, it should be understood that the present disclosure encompasses embodiments of transmissions for bicycles having more or fewer sets of gears or other components (such as sprockets and belts), and the present disclosure encompasses embodiments of transmissions for other vehicles subject to other practical constraints.

[0016] Another aspect of embodiments of the present disclosure is to provide a driven assembly and an output gear to transmit power from the driven sprocket and the countershaft to the drive wheel, which in turn powers the rear wheel and propels the vehicle. The rotational speed of the sprocket and belt is increased to reduce the torque within the transmission, however now the torque needs to be increased to be useful for the drive wheel and to propel the vehicle. The driven assembly is positioned around and engages with the countershaft. The driven assembly can be one or more planetary gear sets that reduce speed and increase torque. In these embodiments, the driven assembly is a driven gear assembly. Then, in some embodiments, the output of the driven gear assembly engages with a first output gear positioned around the countershaft. Another second output gear is positioned around the crankshaft and engages with the first output gear. Finally, in various embodiments, the second output gear transmits power to the drive wheel to propel the bicycle. It should be understood that in some embodiments, a belt transmits power from the driven assembly to the drive wheel, or the driven assembly includes components such as sprockets, belts, etc.

[0017] Another aspect of embodiments of the present disclosure is to provide a controller to coordinate and operate the various components of the transmission, particularly the position motor. In some embodiments, the transmission includes a battery that communicates with the controller to power the position motor, and includes a generator that engages with the rotating components of the transmission to transmit electricity to the battery. Based on one or more input signals, the controller can indicate the amount of electricity transmitted to the position motor. Further, the controller can transmit an output signal to the position motor to control various aspects of the position motor, such as the speed or acceleration of the output shaft, the rotational direction of the output shaft, etc.

[0018] Various devices can transmit one or more input signals to the controller, for example to change the speed ratio of the transmission. For example, a shifter on the handlebars of a bicycle can transmit an input signal to the controller. The user shifts a dial or paddle, and a position sensor detects the shift and transmits an input signal to the controller. Similarly, a torque sensor can detect the torque applied by the user to the crankshaft and transmit an input signal to the controller. The controller can process one or more input signals and then indicate the flow of electricity to the position motor and any output signals to the position motor to set the appropriate speed ratio of the transmission.

[0019] One aspect of embodiments of the present disclosure is to provide a continuously variable transmission having a set of driver sheaves positioned around a countershaft and a set of driven sheaves positioned around a crankshaft. A drive assembly transmits power from the crankshaft to the countershaft, and the countershaft transmits power to the driver sheaves. Then, the driver sheaves transmit power to the driven sheaves via a belt, and the driven sheaves transmit power to a drive wheel via, for example, a driven assembly. With this arrangement and a position motor positioned adjacent to the movable driver sheaves, the number and complexity of parts are reduced. The position motor controls the speed ratio of the transmission by controlling the position of the movable driver sheaves. As a result, the transmission is more sensitive to input from a user or other person and changes the speed ratio more quickly.

[0020] In embodiments where the driver sheaves are positioned around the countershaft, and in other embodiments, the drive assembly and the driven assembly can include multiple gears, sprockets, belts, etc. to transmit power. In some embodiments, the drive assembly includes a first gear positioned around the crankshaft, a second gear positioned around an intermediate shaft and meshing with the first gear, a third gear positioned around the intermediate shaft, and a fourth gear positioned around the countershaft and meshing with the third gear. Thus, power is transmitted from the crankshaft to the first gear, and the first gear drives the second gear and the intermediate shaft. Then, the intermediate shaft transmits power to the third gear, the fourth gear, and the countershaft. The size and arrangement of the gears are such that the countershaft rotates at a greater speed and a smaller torque than the crankshaft, which reduces wear and tear on the components of the transmission.

[0021] Similarly, the driven assembly can include multiple gears, sprockets, belts, etc. to transmit power. In some embodiments, the driven assembly includes a sun gear that receives power from the driven sheaves, planetary gears, a carrier connected to the planetary gears, and a ring gear. The carrier serves as the output of the driven assembly and transmits power to a drive wheel such that the drive wheel rotates at a smaller speed and a greater torque than the driven sheaves. In other embodiments, the driven assembly can span between the countershaft and the crankshaft, where a first sprocket is positioned around the countershaft, a second sprocket is positioned around the crankshaft, and a timing belt connects the sprockets. Power is transmitted from the countershaft to the first sprocket, the belt, and the second sprocket, and then the second sprocket can transmit power to a drive wheel such that the drive wheel rotates at a smaller speed and a greater torque than the countershaft.

[0022] A first aspect of the present disclosure is to provide a continuously variable transmission for a bicycle, comprising: a crankshaft rotatable about a crankshaft axis; a drive gear assembly positioned around the crankshaft, wherein an input end of the drive gear assembly is engaged with the crankshaft, and wherein an output end of the drive gear assembly is configured to rotate at a greater speed and a smaller torque than the crankshaft; a set of driven sheaves positioned around the crankshaft and engaged with the output end of the drive gear assembly; a countershaft rotatable about a countershaft axis; a set of drive sheaves positioned around the countershaft and engaged with the countershaft; a belt coupling the set of drive sheaves and the set of driven sheaves and configured to transmit power from the set of drive sheaves to the set of driven sheaves, wherein a speed ratio between the set of drive sheaves and the set of driven sheaves is continuously variable; and a driven gear assembly positioned around the countershaft, wherein an input end of the driven gear assembly is engaged with the countershaft, wherein an output end of the driven gear assembly is configured to rotate at a smaller speed and a greater torque than the countershaft, and wherein the output end of the driven gear assembly is configured to transmit power to a drive wheel to propel the bicycle.

[0023] The transmission of the first aspect may optionally include: a position motor, wherein the set of driven sheaves includes a fixed sheave; and a movable sheave engaged with the position motor, wherein the position motor is configured to move the movable sheave along the countershaft axis to change the speed ratio between the set of drive sheaves and the set of driven sheaves.

[0024] The transmission of the first aspect may incorporate one or more of the foregoing embodiments and optionally include a biasing member, wherein the set of drive sheaves includes: a fixed sheave; and a movable sheave, wherein the biasing member is configured to act on the movable sheave along the crankshaft axis, and wherein the movable sheave is configured to change its position along the crankshaft axis to accommodate the speed ratio established by the set of driven sheaves.

[0025] The transmission of the first aspect may include one or more of the foregoing embodiments, and optionally, the drive gear assembly includes: a first planetary gear set having a ring gear, a plurality of first planetary gears, a first carrier, and a first sun gear, wherein the first carrier is an input end of the drive gear assembly, and the first carrier is configured to drive the plurality of first planetary gears between the ring gear and the first sun gear such that the first sun gear rotates at a greater speed and with a smaller torque than the crankshaft; and a second planetary gear set having a plurality of second planetary gears, a second carrier, and a second sun gear, wherein the second carrier engages the first sun gear, and the second carrier is configured to drive the plurality of second planetary gears between the ring gear and the second sun gear such that the second sun gear rotates at a greater speed and with a smaller torque than the first sun gear, and wherein the second sun gear is an output end of the drive gear assembly.

[0026] The transmission of the first aspect may include one or more of the foregoing embodiments, and optionally, the first planetary gear set has a gear ratio, the second planetary gear set has a gear ratio, and wherein the gear ratio is between approximately 1:3.5 and 1:4.5.

[0027] The transmission of the first aspect may include one or more of the foregoing embodiments, and optionally, the driven gear assembly includes a planetary gear set having a ring gear, a plurality of planetary gears, and a sun gear, wherein the sun gear is an input end of the driven gear assembly, wherein the sun gear is configured to drive the plurality of planetary gears, wherein the plurality of planetary gears are configured to drive the ring gear at a smaller speed and with a greater torque than the sun gear, and wherein the ring gear is an output end of the driven gear assembly.

[0028] The transmission of the first aspect may include one or more of the foregoing embodiments, and optionally includes: a drive wheel positioned around the crankshaft; and an output gear positioned around the crankshaft and engaging the drive wheel, wherein teeth extending around an outer surface of the ring gear are configured to transmit power to the output gear, and wherein the output gear is configured to transmit power to the drive wheel to propel the bicycle.

[0029] A second aspect of the present disclosure is to provide a continuously variable transmission system for a bicycle, comprising: a crankshaft rotatable about a crankshaft axis; a fixed drive pulley and a movable drive pulley positioned around the crankshaft, wherein the fixed drive pulley and the movable drive pulley are configured to receive power from the crankshaft; a countershaft rotatable about a countershaft axis; a fixed driven pulley and a movable driven pulley positioned around the countershaft; a belt coupling the fixed drive pulley and the movable drive pulley to the fixed driven pulley and the movable driven pulley, wherein the belt is configured to transmit power from the fixed drive pulley and the movable drive pulley to the fixed driven pulley and the movable driven pulley, and wherein the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley is continuously variable; a biasing member configured to act on the movable drive pulley along the crankshaft axis, wherein the movable drive pulley changes position along the crankshaft axis to accommodate the speed ratio established by the fixed driven pulley and the movable driven pulley; and a position motor engaged with the movable driven pulley, wherein the position motor is configured to move the movable driven pulley along the countershaft axis to change the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley.

[0030] The transmission of the second aspect may optionally comprise that the position motor is a servo motor with an output shaft, and wherein rotation of the output shaft causes the movable driven pulley to move along the countershaft axis.

[0031] The transmission of the second aspect may comprise one or more of the foregoing embodiments and optionally comprise: an eccentric cam connected to the output shaft of the servo motor; and a hub connected to the movable driven pulley, wherein the eccentric cam extends into a groove of the hub, and rotation of the output shaft causes the eccentric cam to rotate and causes the hub and the movable driven pulley to move along the countershaft axis, which changes the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley.

[0032] The transmission device of the second aspect may include one or more of the foregoing embodiments, and optionally includes: a controller in communication with the position motor; and a shifter in communication with the controller, wherein the shifter is configured to transmit an input signal to the controller, and the controller is configured to cause the position motor to move the movable driven sheave along the secondary axis to change the speed ratio between the fixed drive sheave and the movable drive sheave and the fixed driven sheave and the movable driven sheave.

[0033] The transmission device of the second aspect may include one or more of the foregoing embodiments, and optionally includes: a controller in communication with the position motor; and a torque sensor operably engaged with the crankshaft and in communication with the controller, wherein the torque sensor is configured to transmit an input signal to the controller, and the controller is configured to cause the position motor to move the movable driven sheave along the secondary axis to change the speed ratio between the fixed drive sheave and the movable drive sheave and the fixed driven sheave and the movable driven sheave.

[0034] The transmission device of the second aspect may include one or more of the foregoing embodiments, and optionally includes: a plurality of pins extending from the secondary shaft; and a plurality of slots extending through a portion of the movable driven sheave, and wherein the plurality of pins are positioned in the corresponding plurality of slots such that the movable driven sheave is movable relative to the secondary shaft along the secondary axis.

[0035] The transmission device of the second aspect may include one or more of the foregoing embodiments, and optionally, each of the plurality of slots extends along a line that is not parallel to the secondary axis.

[0036] The transmission device of the second aspect may include one or more of the foregoing embodiments, and optionally, the slotted portion of the movable driven sheave may be a cylindrical portion and / or a portion positioned around the secondary shaft.

[0037] The transmission device of the second aspect may include one or more of the foregoing embodiments, and optionally, the slotted portion of the movable driven sheave is a portion that does not contact the belt.

[0038] A third aspect of the present disclosure is to provide a continuously variable transmission for a bicycle, comprising: a housing extending from a first side to a second side; a fixed drive pulley and a movable drive pulley rotatable about a crankshaft axis, wherein the movable drive pulley is positioned between the first side of the housing and the fixed drive pulley; a countershaft at least partially positioned within the housing and rotatable about a countershaft axis; a fixed driven pulley and a movable driven pulley positioned around the countershaft, wherein the fixed driven pulley is positioned between the first side of the housing and the movable driven pulley; a plurality of pins extending from the countershaft; a plurality of slots extending through the movable driven pulley, wherein the plurality of pins are positioned within the corresponding plurality of slots such that the movable driven pulley is movable relative to the countershaft along the countershaft axis; and a belt coupling the two drive pulleys and the two driven pulleys, wherein the belt is configured to transmit power from the two drive pulleys to the two driven pulleys, wherein the speed ratio between the two drive pulleys and the two driven pulleys is continuously variable, and wherein power is configured to be transmitted to the countershaft to propel the bicycle.

[0039] The transmission of the third aspect may optionally include that the slotted portion of the movable driven pulley may be a cylindrical portion and / or a portion positioned around the countershaft.

[0040] The transmission of the third aspect may include one or more of the foregoing embodiments, and optionally, the slotted portion of the movable driven pulley is a portion that does not contact the belt.

[0041] The transmission of the third aspect may include one or more of the foregoing embodiments, and optionally includes: a position motor engaged with the movable driven pulley, wherein the position motor is configured to move the movable driven pulley along the countershaft axis to change the speed ratio between the two drive pulleys and the two driven pulleys; and a biasing member configured to act on the movable drive pulley along the crankshaft axis, wherein the movable drive pulley is configured to change position along the crankshaft axis to accommodate the speed ratio established by the two driven pulleys.

[0042] The transmission of the third aspect may include one or more of the foregoing embodiments and optionally includes a drive gear assembly positioned between the first side of the housing and the movable drive sheave, wherein an input end of the drive gear assembly is configured to receive power from a crankshaft, an output end of the drive gear assembly is configured to rotate at a greater speed and a smaller torque than the crankshaft, and the two drive sheaves engage with the output end of the drive gear assembly.

[0043] The transmission of the third aspect may include one or more of the foregoing embodiments and optionally includes a driven gear assembly positioned around the countershaft between the first side of the housing and the fixed driven sheave, wherein an input end of the driven gear assembly engages with the countershaft, and an output end of the driven gear assembly is configured to rotate at a smaller speed and a greater torque than the countershaft.

[0044] The transmission of the third aspect may include one or more of the foregoing embodiments and optionally, the drive gear assembly and the driven gear assembly are positioned in a sealed portion of the housing, and the sealed portion is at least partially filled with a lubricant.

[0045] The transmission of the third aspect may include one or more of the foregoing embodiments and optionally, the belt has a V-shaped cross-section, and inner surfaces of the two drive sheaves and inner surfaces of the two driven sheaves are tapered to complement side surfaces of the V-shaped belt.

[0046] A fourth aspect of the present disclosure is to provide a continuously variable transmission for a bicycle, including: a crankshaft rotatable about a crankshaft axis; a countershaft rotatable about a countershaft axis; a drive assembly having an input end engaging with the crankshaft and an output end engaging with the countershaft, wherein the crankshaft drives the drive assembly, and the drive assembly drives the countershaft so that the countershaft rotates at a greater speed and a smaller torque than the crankshaft; a set of drive sheaves positioned around the countershaft and engaging with the countershaft; a set of driven sheaves positioned around the crankshaft; a belt coupling the set of drive sheaves and the set of driven sheaves and configured to transmit power from the set of drive sheaves to the set of driven sheaves, wherein a speed ratio between the set of drive sheaves and the set of driven sheaves is continuously variable; and a driven assembly positioned around the crankshaft, wherein an input end of the driven assembly engages with the set of driven sheaves, an output end of the driven assembly is configured to rotate at a smaller speed and a greater torque than the set of driven sheaves, and the output end of the driven assembly is configured to transmit power to propel the bicycle.

[0047] The transmission of the fourth aspect may optionally include: a position motor, wherein the set of driver sheaves includes a fixed sheave; and a movable sheave engaged with the position motor, wherein the position motor is configured to move the movable sheave along the secondary axis to change the speed ratio between the set of driver sheaves and the set of driven sheaves.

[0048] The transmission of the fourth aspect may include one or more of the foregoing embodiments and optionally include a biasing member, wherein the set of driven sheaves includes: a fixed sheave; and a movable sheave, wherein the biasing member is configured to act on the movable sheave along the crankshaft axis, and wherein the movable sheave is configured to change position along the crankshaft axis to accommodate the speed ratio established by the set of driver sheaves.

[0049] The transmission of the fourth aspect may include one or more of the foregoing embodiments and optionally, the drive assembly includes: a first gear positioned around the crankshaft and being an input end of the drive assembly, and a second gear positioned around an intermediate shaft and engaged with the intermediate shaft, wherein the crankshaft drives the first gear, and the first gear drives the second gear such that the intermediate shaft rotates at a greater speed and a smaller torque than the crankshaft; and a third gear positioned around the intermediate shaft and engaged with the intermediate shaft, and a fourth gear positioned around the secondary shaft and being an output end of the drive assembly, wherein the intermediate shaft drives the third gear, and the third gear drives the fourth gear such that the secondary shaft rotates at a greater speed and a smaller torque than the intermediate shaft.

[0050] The transmission of the fourth aspect may include one or more of the foregoing embodiments and optionally, the gear ratio between the input end and the output end of the drive assembly is between approximately 1:3.8 and 1:14.5.

[0051] The transmission of the fourth aspect may include one or more of the foregoing embodiments and optionally, the driven assembly includes a planetary gear set having a ring gear, a plurality of planetary gears, a carrier connecting the plurality of planetary gears, and a sun gear, wherein the sun gear is an input end of the driven assembly, wherein the sun gear is configured to drive the plurality of planetary gears against the ring gear such that the carrier rotates at a smaller speed and a greater torque than the sun gear, and wherein the carrier is an output end of the driven assembly.

[0052] The transmission device according to the fourth aspect may include one or more of the foregoing embodiments, and optionally, the driven assembly includes: a first sprocket serving as an input end of the driven assembly, and a second sprocket serving as an output end of the driven assembly; and a belt connecting the first sprocket and the second sprocket.

[0053] A fifth aspect of the present disclosure is to provide a continuously variable transmission device system for a bicycle, which includes: a crankshaft rotatable about a crankshaft axis; a countershaft rotatable about a countershaft axis; a fixed drive pulley and a movable drive pulley positioned around the countershaft, wherein the fixed drive pulley and the movable drive pulley are configured to receive power from the countershaft; a fixed driven pulley and a movable driven pulley positioned around the crankshaft; a belt connecting the fixed drive pulley and the movable drive pulley to the fixed driven pulley and the movable driven pulley, wherein the belt is configured to transmit power from the fixed drive pulley and the movable drive pulley to the fixed driven pulley and the movable driven pulley, and wherein the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley is continuously variable; a biasing member configured to act on the movable driven pulley along the crankshaft axis, wherein the movable driven pulley changes its position along the crankshaft axis to adapt to the speed ratio established by the fixed drive pulley and the movable drive pulley; and a position motor engaged with the movable drive pulley, wherein the position motor is configured to move the movable drive pulley along the countershaft axis to change the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley.

[0054] Optionally, the transmission device according to the fifth aspect may include that the position motor is a servo motor with an output shaft, and wherein the rotation of the output shaft moves the movable drive pulley along the countershaft axis.

[0055] The transmission device according to the fifth aspect may include one or more of the foregoing embodiments, and optionally includes: an eccentric cam connected to the output shaft of the servo motor; and a hub configured to move along the countershaft axis, wherein the eccentric cam extends into a groove of the hub, and the rotation of the output shaft causes the eccentric cam to rotate and causes the hub to move the movable drive pulley along the countershaft axis, which changes the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley.

[0056] The transmission of the fifth aspect may include one or more of the foregoing embodiments and optionally includes: a controller in communication with the position motor; and a shifter in communication with the controller, wherein the shifter is configured to transmit an input signal to the controller, and the controller is configured to cause the position motor to move the movable drive sheave along the secondary axis to change the speed ratio between the fixed drive sheave and the movable drive sheave and the fixed driven sheave and the movable driven sheave.

[0057] The transmission of the fifth aspect may include one or more of the foregoing embodiments and optionally includes: a controller in communication with the position motor; and a torque sensor operably engaged with the crankshaft and in communication with the controller, wherein the torque sensor is configured to transmit an input signal to the controller, and the controller is configured to cause the position motor to move the movable drive sheave along the secondary axis to change the speed ratio between the fixed drive sheave and the movable drive sheave and the fixed driven sheave and the movable driven sheave.

[0058] The transmission of the fifth aspect may include one or more of the foregoing embodiments and optionally includes: a drive assembly having an input end engaged with the crankshaft and an output end engaged with the secondary shaft, wherein the crankshaft drives the drive assembly, and the drive assembly drives the secondary shaft such that the secondary shaft rotates at a greater speed and a smaller torque than the crankshaft; and a driven assembly positioned around the crankshaft, wherein the input end of the driven assembly is engaged with the fixed driven sheave and the movable driven sheave, wherein the output end of the driven assembly is configured to rotate at a smaller speed and a greater torque than the fixed driven sheave and the movable driven sheave, and wherein the output end of the driven assembly is configured to transmit power to propel the bicycle.

[0059] The transmission of the fifth aspect may include one or more of the foregoing embodiments and optionally, the biasing member is a spring that produces either a linear changing force or a non-linear changing force in response to displacement.

[0060] The sixth aspect of the present disclosure is to provide a continuously variable transmission for a bicycle, which includes: a housing extending from a first side to a second side; a crankshaft rotatable about a crankshaft axis, wherein the crankshaft is at least partially positioned in the housing; a countershaft rotatable about a countershaft axis, wherein the countershaft is positioned in the housing; a fixed drive pulley and a movable drive pulley positioned around the countershaft, wherein the fixed drive pulley and the movable drive pulley are positioned in the housing, and the movable drive pulley is positioned between the fixed drive pulley and the first side of the housing, wherein the fixed drive pulley and the movable drive pulley are configured to receive power from the countershaft; a fixed driven pulley and a movable driven pulley positioned around the crankshaft, wherein the fixed driven pulley and the movable driven pulley are positioned in the housing, and the movable driven pulley is positioned between the fixed driven pulley and the second side of the housing; a belt configured to transmit power from the fixed drive pulley and the movable drive pulley to the fixed driven pulley and the movable driven pulley, and wherein the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley is continuously variable; and a position motor positioned between the movable drive pulley and the first side of the housing, wherein the position motor is configured to move the movable drive pulley along the countershaft axis to change the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley.

[0061] The transmission of the sixth aspect may optionally include a biasing member configured to act on the movable driven pulley along the crankshaft axis, wherein the biasing member is positioned between the movable driven pulley and the second side of the housing, and the movable driven pulley changes its position along the crankshaft axis to accommodate the speed ratio established by the fixed drive pulley and the movable drive pulley.

[0062] The transmission of the sixth aspect may include one or more of the foregoing embodiments and optionally includes: a fixed collar positioned around the crankshaft, wherein the fixed driven pulley engages with the fixed collar; a movable collar positioned around the fixed collar, wherein the movable driven pulley engages with the movable collar; a plurality of pins extending from the fixed collar into corresponding slots of the movable collar, such that the movable collar and the movable driven pulley are configured to transmit power to the fixed collar and move along the crankshaft axis.

[0063] The transmission device of the sixth aspect may include one or more of the foregoing embodiments, and optionally includes: a driver assembly positioned between the second side of the housing and the fixed driver sheave, wherein the driver assembly is configured to transmit power from the crankshaft to the countershaft so that the countershaft rotates at a greater speed and a smaller torque than the crankshaft; and a driven assembly positioned around the crankshaft between the first side of the housing and the fixed driven sheave, wherein the driven assembly is configured to transmit power from the fixed driven sheave and the movable driven sheave to the drive wheel so that the drive wheel rotates at a smaller speed and a greater torque than the fixed driven sheave and the movable driven sheave.

[0064] The transmission device of the sixth aspect may include one or more of the foregoing embodiments, and optionally, the driver assembly is positioned in the first sealed portion of the housing configured to receive lubricant, and the driven assembly is positioned in the second sealed portion of the housing configured to receive lubricant.

[0065] The transmission device of the sixth aspect may include one or more of the foregoing embodiments, and optionally, the belt has a V-shaped cross-section, and the inner surfaces of the fixed driver sheave and the movable driver sheave and the inner surfaces of the fixed driven sheave and the movable driven sheave are tapered to complement the side surfaces of the V-shaped belt.

[0066] As used herein, the phrases "at least one", "one or more", and "and / or" are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions "at least one of A, B, and C", "at least one of A, B, or C", "one or more of A, B, and C", "one or more of A, B, or C", and "A, B, and / or C" means only A, only B, only C, A and B together, A and C together, B and C together, or A, B, and C together.

[0067] Unless otherwise specified, all numbers representing quantities, dimensions, conditions, etc. used in the specification and claims should be understood to be modified by the term "about" in all cases.

[0068] As used herein, the term "a" entity means one or more of that entity. Thus, the terms "a", "one or more", and "at least one" may be used interchangeably herein.

[0069] As used herein, the use of "comprising", "including", or "having" and their variants is intended to cover the items listed thereafter and their equivalents as well as additional items. Accordingly, the terms "comprising", "including", or "having" and their variants may be used interchangeably herein. The use of "engaged with" and its variants herein is intended to cover any direct or indirect connection between components.

[0070] It should be understood that, as used herein, in accordance with 35 U.S.C. § 112(f), the term "means" shall be given its broadest possible interpretation. Accordingly, claims containing the term "means" shall cover all structures, materials, or acts set forth herein, as well as all equivalents thereof. In addition, structures, materials, or acts and their equivalents shall include all those described in the Summary of the Invention, the Description of the Drawings, the Detailed Description, the Abstract, and the claims themselves.

[0071] These and other advantages will be apparent in light of the disclosure of the invention contained herein. The above embodiments, objectives, and configurations are neither complete nor exhaustive. The Summary of the Invention is neither intended nor should it be construed as representing the entire content and scope of the disclosure. In addition, references herein to "the invention" or aspects thereof should be understood to mean certain embodiments of the invention / disclosure and should not be construed as limiting all embodiments to a particular description. The invention is set forth in various levels of detail in the Summary of the Invention, the Description of the Drawings, and the Detailed Description, and there is no intention to limit the scope of the invention by including or excluding elements or components in the Summary of the Invention. Additional aspects of the invention will become more apparent in light of the Detailed Description, particularly when taken in conjunction with the drawings.

[0072] It should be understood that any feature or aspect described herein may be claimed in combination with any other feature or aspect described herein, regardless of whether those features or aspects are from the same described embodiment.

[0073] Any one or more aspects described herein may be combined with any other one or more aspects described herein. Any one or more features described herein may be combined with any other one or more features described herein. Any one or more embodiments described herein may be combined with any other one or more embodiments described herein. Description of the Drawings

[0074] Those skilled in the art should recognize that the following description is merely an illustrative example of the principles of the present disclosure, and the principles of the present disclosure can be applied in various ways to provide many different alternative embodiments. This description is intended to illustrate the general principles of the teachings of the present disclosure and is not intended to limit the inventive concepts disclosed herein.

[0075] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments and, together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of the invention.

[0076] Figure 1 A side elevation view of a part of a bicycle having a transmission according to an embodiment of the present disclosure;

[0077] Figure 2A For Figure 1 A side elevation view of a transmission according to an embodiment of the present disclosure in

[0078] Figure 2B A top view cross-section of a transmission according to an embodiment of the present disclosure taken along line A-A in Figure 2A ;

[0079] Figure 3A A perspective view of a first planetary gear set according to an embodiment of the present disclosure;

[0080] Figure 3B For Figure 3A A perspective view of a first planetary gear set according to an embodiment of the present disclosure in

[0081] Figure 3C A perspective view of a second planetary gear set according to an embodiment of the present disclosure;

[0082] Figure 4A For Figure 1 A perspective view of a part of a transmission according to an embodiment of the present disclosure in a high speed ratio state in

[0083] Figure 4B For Figure 1 A perspective view of a part of a transmission according to an embodiment of the present disclosure in a low speed ratio state in

[0084] Figure 5 For Figure 1 A perspective view of a part of a transmission according to an embodiment of the present disclosure in

[0085] Figure 6 For Figure 1A perspective view of the position motor, the hub, and the countershaft of the transmission device according to an embodiment of the present disclosure;

[0086] Figure 7 A perspective view of the third planetary gear set according to an embodiment of the present disclosure;

[0087] Figure 8 A perspective view of the output gear and the drive wheel according to an embodiment of the present disclosure;

[0088] Figure 9 A schematic diagram of the controller and other components according to an embodiment of the present disclosure;

[0089] Figure 10 A perspective view of the transmission device according to an embodiment of the present disclosure;

[0090] Figure 11 For the transmission device according to an embodiment of the present disclosure along Figure 10 A bottom view cross-sectional view taken along line B-B in;

[0091] Figure 12 Is Figure 10 A perspective view of the drive assembly of the transmission device according to an embodiment of the present disclosure in;

[0092] Figure 13 Is Figure 10 A perspective view of the position motor of the transmission device according to an embodiment of the present disclosure in;

[0093] Figure 14 Is Figure 10 A perspective view of the fixed driven sprocket of the transmission device according to an embodiment of the present disclosure in;

[0094] Figure 15 Is Figure 10 A perspective view of the driven assembly of the transmission device according to an embodiment of the present disclosure in;

[0095] Figure 16 A perspective view of the transmission device according to an embodiment of the present disclosure;

[0096] Figure 17 For the transmission device according to an embodiment of the present disclosure along Figure 16 A top view cross-sectional view taken along line C-C in; and

[0097] Figure 18 Is Figure 16 A perspective view of the driven assembly of the transmission device according to an embodiment of the present disclosure.

[0098] It should be understood that the accompanying drawings are not necessarily drawn to scale and that various dimensions may be changed. In some cases, details that are not necessary for understanding the present invention or that make other details difficult to understand may have been omitted. Of course, it should be understood that the present invention is not necessarily limited to the specific embodiments illustrated herein.

[0099] 2 Bicycle

[0100] 4 Crankshaft

[0101] 6 Pedal

[0102] 8 Driving wheel

[0103] 10 Chain

[0104] 12 Rear hub

[0105] 14 Rear wheel

[0106] 16 Transmission

[0107] 18 Housing

[0108] 20 First part

[0109] 22 Second part

[0110] 24 Crankshaft axis

[0111] 26 First planetary gear set

[0112] 28 Second planetary gear set

[0113] 30 Fixed drive sheave

[0114] 32 Movable drive sheave

[0115] 34 Biasing member

[0116] 36 Belt

[0117] 38 Countershaft

[0118] 40 Countershaft axis

[0119] 42 Fixed driven sheave

[0120] 44 Movable driven sheave

[0121] 46 Position motor

[0122] 48 Third planetary gear set

[0123] 50 First output gear

[0124] 52 Second output gear

[0125] 54 First bracket

[0126] 56-tooth ring gear

[0127] 58a, 58b first planet gears

[0128] 58c, 58d first planet gears

[0129] 60 first sun gear

[0130] 62 second bracket

[0131] 64a, 64b second planet gears

[0132] 66 second sun gear

[0133] 68 drive shaft

[0134] 70 drive pin

[0135] 72 drive slot

[0136] 74 driven slot

[0137] 76 driven pin

[0138] 77 screw

[0139] 78 hub

[0140] 80 output shaft

[0141] 82 eccentric cam

[0142] 84 groove

[0143] 86 third sun gear

[0144] 88a, 88b third planet gears

[0145] 90 third ring gear

[0146] 92 input end

[0147] 94 controller

[0148] 96 battery

[0149] 98 electric motor

[0150] 100 transmission

[0151] 102 housing

[0152] 104 crankshaft

[0153] 106 first part

[0154] 107 first side

[0155] 108 Second part

[0156] 109 Second side

[0157] 110 Crankshaft axis

[0158] 112 Intermediate shaft

[0159] 114 Intermediate axis

[0160] 116 Countershaft

[0161] 118 Countershaft axis

[0162] 120 Driving wheel

[0163] 122 Drive gear assembly

[0164] 124 First gear

[0165] 126 Second gear

[0166] 128 Third gear

[0167] 130 Fourth gear

[0168] 132 Fixed drive sheave

[0169] 134 Movable drive sheave

[0170] 136 Position motor

[0171] 140 Hub

[0172] 142 Output shaft

[0173] 144 Eccentric cam

[0174] 146 Belt

[0175] 148 Fixed driven sheave

[0176] 150 Movable driven sheave

[0177] 152 Biasing member

[0178] 154 Driven gear assembly

[0179] 156 Sun gear

[0180] 158 Planet gear

[0181] 160 Bracket

[0182] 162 Ring gear

[0183] 164 First sealing part

[0184] 166 Second sealing part

[0185] 168 Groove

[0186] 170 Fixed collar

[0187] 172 Pin

[0188] 174 Movable collar

[0189] 176 Slot

[0190] 177 Slot axis

[0191] 178 Transmission

[0192] 180 Housing

[0193] 182 Crankshaft

[0194] 184 Crankshaft axis

[0195] 186 Countershaft

[0196] 188 Countershaft axis

[0197] 190 Driving wheel

[0198] 192 Drive gear assembly

[0199] 194 Fixed drive sheave

[0200] 196 Movable drive sheave

[0201] 198 Biasing member

[0202] 200 Belt

[0203] 202 Fixed driven sheave

[0204] 204 Movable driven sheave

[0205] 206 Positioning motor

[0206] 208 Driven sprocket assembly

[0207] 210 Driving sprocket

[0208] 212 Belt

[0209] 214 Driven sprocket Detailed implementation mode

[0210] Although the following text describes many different embodiments in detail, it should be understood that the legal scope of the description is defined by the language of the claims set forth at the end of this disclosure. The detailed description is to be construed as exemplary only and does not describe every possible embodiment, as describing every possible embodiment of a transmission would be impracticable if not impossible. Many alternative embodiments can be implemented using current technology or technology developed after the filing date of this patent application, and these embodiments will still fall within the scope of the claims. Additionally, any combination of the features shown in the various figures can be used to create additional embodiments of this disclosure. Thus, the dimensions, aspects, and features of one embodiment of a transmission can be combined with the dimensions, aspects, and features of another embodiment of a transmission to create the claimed embodiments.

[0211] Figure 1 FIG. 2 shows a portion of a bicycle 2 having a continuously variable transmission 16 of the present disclosure. A user engages a pedal 6 to rotate a crankshaft 4 and a drive wheel 8, which in this embodiment is a sprocket. Rotation of the drive wheel 8 causes a chain 10 engaged with a sprocket of a rear hub 12 to rotate, and rotation of the rear hub 12 drives a rear wheel 14 to propel the bicycle 2.

[0212] In some embodiments, the bicycle 2 will have multiple sprockets at the rear hub 12 and / or the crankshaft 4, and a gear shifting system moves the chain 10 between these different sprockets to change the gear ratio between the rear hub 12 and the crankshaft 4. The transmission 16 of the present disclosure eliminates the need for multiple sprockets at the rear hub 12 and / or the crankshaft 4. However, it should be understood that embodiments of the present disclosure can be used with a gear shifting system in addition to multiple sprockets at the rear hub 12 and / or the crankshaft. Additionally, it should be understood that embodiments of the present disclosure can be used with, for example, an electric motor, a controller, and / or a battery on an electric bicycle and other components on a bicycle.

[0213] Figure 2A FIG. 3 shows a side elevational view of the continuously variable transmission 16 of the present disclosure. The transmission 16 has a crankshaft 4, a drive wheel 8, and other components described herein to change the speed ratio of the transmission 16 and to coordinate the force applied by the user with the movement of the bicycle, whether the bicycle is stationary or moving at a particular speed. In various embodiments, a user can choose to customize the bicycle, such as choosing the crankshaft 4, the drive wheel 8, the pedals, or the crank arms that connect the pedals to the crankshaft 4. Thus, the term "transmission" can encompass embodiments with or without these components. In Figure 2A line A - A is also shown.

[0214] Figure 2B FIG. 4 shows the continuously variable transmission 16 along Figure 2AA top view cross-sectional view taken along line A-A in [description]. The crankshaft 4 is rotatable about a crankshaft axis 24, the drive wheel 8 is positioned about the crankshaft 4, and there are several components to couple the power applied by the user to the crankshaft 4 and the drive wheel 8, and the drive wheel 8 transmits power to the rear hub to propel the bicycle.

[0215] The transmission 16 has a set of drive sheaves 30, 32 that drive a belt 36, and then the belt 36 transmits power to a set of driven sheaves 42, 44. The set of driven sheaves 42, 44 changes and establishes the speed ratio between the sets of sheaves in a continuous manner, and the system of sheaves and belt 36 works more efficiently at higher rotational speeds. Specifically, at higher rotational speeds, the force or torque is smaller, which increases the reliability and lifespan of the components of the transmission 16. Thus, in some embodiments, the drive assembly has an input end that engages the crankshaft 4, and the drive assembly has an output end that engages the drive sheaves 30, 32, which rotate at a greater speed and a smaller torque than the crankshaft. In Figure 2B one embodiment, the drive assembly (which can be referred to as a drive gear assembly in this case) includes a first planetary gear set 26 and a second planetary gear set 28, where the first planetary gear set 26 has an input end that engages the crankshaft 4 and an output end that engages the input end of the second planetary gear set 28. Then, the second planetary gear set 28 has an output end that engages the set of drive sheaves 30, 32.

[0216] In some embodiments, the transmission 16 is located at the bottom bracket of the bicycle frame, where the crankshaft 4 extends through the transmission 16. Thus, the drive gear assembly is constrained by its position about the crankshaft 4 and the distance between the crank arms on the crankshaft 4. Additionally, since some components of the bicycle are connected in a certain arrangement and some components maintain a certain clearance distance above the ground, etc., the drive gear assembly is constrained by the overall shape factor of the transmission 16 and the housing 18. Thus, a series of two planetary gear sets 26, 28 achieve a total gear reduction ratio between approximately 1:12.2 and 1:20.3 to meet these constraints. In various embodiments, each planetary gear set 26, 28 has a gear ratio between approximately 1:3.5 and 1:4.5. In some embodiments, each planetary gear set 26, 28 has a gear ratio of approximately 1:4. In some embodiments, each planetary gear set 26, 28 has the same gear ratio, while in other embodiments, the planetary gear sets 26, 28 have different gear ratios.

[0217] It should be understood that although two planetary gear sets 26, 28 are depicted in the figures, the present disclosure encompasses embodiments of a drive gear assembly having any number of gear sets, gear sets other than planetary gear sets, sprockets, belts, etc. For example, in some embodiments, the drive gear assembly has a single planetary gear set to provide a desired gear ratio, or even a spur gear system. Additionally, it should be understood that the gear ratios defined above are exemplary in nature. For example, a single planetary gear set can have a gear ratio of approximately 1:2 to 1:20.

[0218] Many components of the transmission 16 are disposed within the housing 18, and the housing 18 can have a first portion 20 on a first side and a second portion 22 on a second side. The first and second planetary gear sets 26, 28 are disposed in the first portion 20 of the transmission 16 such that the first portion 20 can be sealed and at least partially filled with lubricant to facilitate the operation of the first and second planetary gear sets 26, 28 and other components described herein. The sheaves 30, 32, 42, 44 and the belt 36 are disposed in the second portion 22, which can be sealed without lubricant but can still protect the sheaves 30, 32, 42, 44 and the belt 36 from the external environment.

[0219] The output of the drive gear assembly transmits power to the set of drive sheaves 30, 32. The fixed drive sheave 30 is rotatable about the crankshaft axis 24 but not movable along the crankshaft axis 24, and the movable drive sheave 32 is both rotatable about the crankshaft axis 24 and movable along the crankshaft axis 24. A biasing member 34 acts on the movable drive sheave 32 to bias the movable drive sheave 32 toward the fixed drive sheave 30. The biasing member 34 can have a linear or non-linear response to force and can be, for example, a spring. The variable distance between the drive sheaves 30, 32 accommodates different speed ratios established by the set of driven sheaves 42, 44.

[0220] The set of driven sheaves 42, 44 includes a fixed driven sheave 42 and a movable driven sheave 44, the fixed driven sheave 42 being rotatable about the secondary axis 40 of the secondary shaft 38 but not movable along the secondary axis 40, and the movable driven sheave 44 being both rotatable about the secondary axis 40 and movable along the secondary axis 40. A position motor 46 controls the position of the movable driven sheave 44 along the secondary axis 40 to establish the speed ratio between the sheave sets and thus the overall speed ratio of the transmission 16 - similar to a gear ratio. In some embodiments, the position motor 46 is a servo motor that rotates an output shaft, but it should be understood that the present disclosure encompasses embodiments where the position motor is another device such as an actuator.

[0221] The movable sheave wheels 32, 44 are positioned on opposite sides of the belt 36 to help stabilize the belt 36 within the sheave wheels. Specifically, the movable drive sheave wheel 32 is positioned between the fixed drive sheave wheel 30 and the drive gear assembly, and the fixed driven sheave wheel 42 is positioned between the movable driven sheave wheel 44 and the driven gear assembly. It should be understood that the present disclosure encompasses embodiments having other sheave wheel arrangements.

[0222] The set of driven sheave wheels 42, 44 provides power to the countershaft 38, which rotates at a relatively high speed like the sheave wheels 30, 32, 42, 44 and the belt 36 to reduce the forces on certain components within the transmission 16. The output end of the countershaft 38 engages with the driven assembly to reduce speed and increase torque, which is more effective for powering the drive wheel 8 and ultimately the rear hub 12 of the rear wheel to propel the bicycle. In this embodiment, the driven assembly is the third planetary gear set 48, in which case the driven assembly may be referred to as the driven gear assembly. The output end of the third planetary gear set 48 engages with a first output gear 50 that rotates about the countershaft axis 40. The first output gear 50 engages with a second output gear 52 that rotates about the crankshaft axis 24. This second output gear 52 powers the drive wheel 8. In the depicted embodiment, the output gears 50, 52 have a gear ratio that further reduces speed and increases torque.

[0223] Figure 3A and 3B The first planetary gear set 26 is shown. In this embodiment, the crankshaft 4 is connected to the carrier 54 of the first planetary gear set 26. The carrier 54 drives four planetary gears 58a - 58d disposed within the ring gear 56. Other embodiments within the scope of the present disclosure have more or fewer planetary gears 58a - d. In this embodiment, the ring gear 56 is fixed relative to the housing and does not rotate. The four planetary gears 58a - 58d cause the first sun gear 60 to rotate (i.e., drive the first sun gear 60), which is the output of the first planetary gear set 26. In this embodiment, the gear ratio is 1:4, but it should be understood that the present disclosure encompasses any number of gear ratios. Additionally, it should be understood that the present disclosure encompasses other arrangements of gears or other components in addition to planetary gear sets to increase the rotational speed at the output.

[0224] Figure 3C The second planetary gear set 28 is shown. The same ring gear 56 from the first planetary gear set 26 operates with the components of the second planetary gear set 28. Thus, in various embodiments, the terms "first planetary gear set" and "second planetary gear set" may include the same ring gear 56, different portions of the same ring gear 56, or different ring gears 56. The first sun gear ( Figure 3Bis connected to a second carrier 62 of the second planetary gear set 28. The second carrier 62 drives two planetary gears 64a, 64b which drive a second sun gear 66 which serves as an output of the second planetary gear set 28. The second planetary gear set 28 and other planetary gear sets described herein may have any number of planetary gears, e.g., two, four or more planetary gears.

[0225] Figure 4A and 4B shows the components of the transmission in a high speed ratio state (in Figure 4A and in a low speed ratio state (in Figure 4B ). In Figure 4A , the position motor 46 has moved the movable driven sheave 44 closer to the fixed driven sheave 42, and this relative positioning between the driven sheaves 42, 44 presses the belt 36 away from the axis of rotation of the driven sheaves 42, 44. As a result, the contact position of the belt 36 with the inner surfaces of the driven sheaves 42, 44 is further from the axis of rotation of the driven sheaves 42, 44 than in the low speed ratio state shown in Figure 4B and further from the axis of rotation than the belt 36 in the driver sheaves 30, 32.

[0226] In response to the positioning of the belt 36 at the driven sheaves 42, 44, the belt 36 is pulled inwards at the driver sheaves 30, 32 closer to the axis of rotation of the driver sheaves 30, 32. The inward pull of the belt 36 overcomes the force provided by the biasing member 34 acting on the movable driver sheave 32, and thus the movable driver sheave 32 moves away from the fixed driver sheave 30 (along the crankshaft axis). As a result, the contact position of the belt 36 with the inner surfaces of the driver sheaves 30, 32 is closer to the axis of rotation of the driver sheaves 30, 32 than in the low speed state shown in Figure 4B and closer to the axis of rotation than the belt 36 in the driven sheaves 42, 44. Figure 4A The speed ratio in

[0227] is a higher speed ratio which provides a higher torque and a lower rotational speed more suitable for a stationary or low speed vehicle. Figure 4B In

[0228] Responsive to the relative positioning of the driven sheaves 42, 44, the force provided by the biasing member acting on the movable drive sheave 32 causes the movable drive sheave 32 to move closer to the fixed drive sheave 30 and take up any slack in the belt 36 permitted by the relative positioning of the driven sheaves 42, 44. As a result, the belt 36 contacts the inner surfaces of the drive sheaves 30, 32 away from the axis of rotation of the drive sheaves 30, 32. In this sense, the force caused by the biasing member (which can be a linear or non-linear response) works in concert with any tension from the belt 36 caused by the relative positioning of the driven sheaves 42, 44. Figure 4B The speed ratio in Figure 4B is a lower speed ratio, which provides a smaller torque and a larger rotational speed that are more suitable for a vehicle in motion to achieve a higher speed. As shown in the figure, the belt 36 can have a V-shaped cross-section, where the inner and outer surfaces of the belt 36 are substantially parallel to each other, and the side surfaces of the belt 36 are tapered to complement the inclined inner surfaces of the sheaves 30, 32, 42, 44.

[0229] Figure 5 A perspective view showing the components of the transmission, with the belt, a portion of the movable drive sheave 32, and the fixed driven sheave removed. Starting from the drive side of the transmission, the drive shaft 68 is positioned around the crankshaft 4 and is connected to the output of the drive gear assembly, which in this embodiment is the Figure 3C second sun gear in Figure 3C . It should be understood that in various embodiments, the drive shaft 68 and the second sun gear can be a single component. The drive shaft 68 receives power from the drive gear assembly, and the drive shaft 68 transmits power to the drive sheaves 30, 32. In this embodiment, the drive shaft 68 is directly connected to the fixed drive sheave 30, and the drive shaft 68 is connected to the movable drive sheave 32 through a pin and slot system. A plurality of pins 70 extend outward from the drive shaft 68 and are positioned in corresponding slots 72 in a portion of the movable drive sheave 32. The portion of the movable drive sheave 32 with the slots 72 can be a cylindrical portion and / or a portion positioned around the crankshaft. In some embodiments, the portion of the movable drive sheave 32 with the slots 72 is a portion that does not contact the belt 36. Each slot 72 extends along a line that is not parallel to the crankshaft axis. The angle and orientation of the slots 72 balance multiple functions, which include effectively transmitting power from the drive shaft 68 to the movable drive sheave 32, reducing the force required to move the movable drive sheave 32 along the crankshaft axis, and preventing the belt from slipping relative to the sheaves as the transmission continuously changes between speed ratios.

[0230] Similarly, at the driven side of the transmission, a pin 76 extends from the countershaft 38 and is positioned in a respective slot 74 in a portion of the movable driven sheave 44. The portion of the movable driven sheave 44 with the slots 74 can be a cylindrical portion and / or a portion positioned around the countershaft 38. In some embodiments, the portion of the movable driven sheave 44 with the slots 74 is a portion that does not contact the belt 36. Thus, the movable driven sheave 44, together with the fixed driven sheave 42, transmits power from the belt to the countershaft 38. Additionally, each slot 74 extends along a line that is not parallel to the countershaft axis. The angle and orientation of the slots 74 also balance multiple functions, including effectively transmitting power from the movable driven sheave 44 to the countershaft 38, reducing the force required to move the movable driven sheave 44 along the countershaft axis, and preventing the belt from slipping relative to the sheaves as the transmission continuously changes between speed ratios.

[0231] The position motor 46 engages the hub 78 to move the movable driven sheave 44 along the countershaft axis and establish the speed ratio of the transmission. The hub 78 is offset along the countershaft axis relative to the movable driven sheave 44, and the hub 78 is connected to the movable driven sheave 44 by a plurality of bolts 77. This connection provides space for the fixed driven sheave ( Figure 4A and 4B 42 in) to be connected to the countershaft 38. Although a plurality of bolts 77 are depicted, it should be understood that the present disclosure encompasses other embodiments having different connections (e.g., pins or other connection mechanisms) between the hub 78 and the movable driven sheave 44.

[0232] Figure 6 is a top view of the position motor 46, the hub 78, and the movable driven sheave 44. In this embodiment, the position motor 46 is a servo motor having an output shaft 80. The position motor 46 can rotate the output shaft 80 about its longitudinal axis in a clockwise or counterclockwise direction. An eccentric cam 82 is connected to the output shaft 80 such that rotation of the output shaft 80 also rotates the eccentric cam 82. In one embodiment, the output shaft 80 has a circular cross-section with a flat side, and the eccentric cam 82 has a similarly shaped hole such that the output shaft 80 fits into the eccentric cam 82 like a key into a keyhole. The key connection can be of different shapes, such as square, triangular, hexagonal, circular with depressions and protrusions, etc. The eccentric cam 82 has a generally cylindrical shape, and the central axis of its cylindrical shape is offset from the axis of the output shaft 80. In other words, the output shaft 80 does not pass through the center point (and central axis) of the eccentric cam 82 and / or is not concentric with the center point (and central axis) of the eccentric cam 82. Thus, when the output shaft 80 rotates, the eccentric cam 82 rotates, and the central axis or mass of the eccentric cam 82 moves in a direction parallel to the countershaft axis 40, or as Figure 6Move left and right as shown.

[0233] The eccentric cam 82 is positioned in the groove 84 of the hub 78, and the movement of the hub 78 is restricted to movement along the secondary axis 40. Thus, the movement of the eccentric cam 82 parallel to the secondary axis 40 is transferred to the hub 78, and the hub 78 moves along the secondary axis 40. Since the hub 78 is connected to the movable driven sheave ( Figure 4A and 4B 44 in), when the hub 78 moves along the secondary axis 40, the movable driven sheave ( Figure 4A and 4B 44 in) moves along the secondary axis 40 in response to the rotation of the output shaft 80 of the position motor 46. The position motor 46 can rotate the output shaft 80 with certain characteristics so that the movable driven sheave ( Figure 4A and 4B 44 in) establishes or changes the speed ratio with certain characteristics. The position motor 46 can rotate the output shaft 80 at a predetermined angular velocity, angular momentum, and / or angular acceleration. In addition, the position motor 46 can rotate the output shaft 80 to accommodate a shift or continuously changing speed ratio rather than moving between discrete speed ratios.

[0234] Although the drawings show the position motor 46 controlling the relative positioning of the driven sheave, in some embodiments, the position motor 46 controls the relative positioning of the drive sheave, and the driven sheave is automatically adjusted to the speed ratio established by the position motor 46 and the drive sheave.

[0235] Figure 7 A driven gear assembly is shown, which is the third planetary gear set 48 in this embodiment. The secondary shaft 38 is connected to the input of the third planetary gear set 48, which, in this embodiment, is the third sun gear 86. It should be understood that the secondary shaft 38 and the third sun gear 86 are depicted as separate components, but the present disclosure encompasses additional embodiments that include embodiments where the secondary shaft 38 and the third sun gear 86 are a single component.

[0236] The power transmitted to the third sun gear 86 causes the two planetary gears 88a, 88b to rotate, and the two planetary gears then cause the ring gear 90 to rotate such that the ring gear 90 rotates at a lower speed and greater torque than the secondary shaft 38 and the third sun gear 86. The ring gear 90 is connected to the first output gear 50, and the first output gear 50 has teeth extending around the outer surface of the first output gear 50. In some embodiments, the ring gear 90 and the first output gear 50 are separate components, while in some embodiments, the ring gear 90 and the first output gear 50 are a single component, which can be described as a ring gear 90 having teeth extending around the inner and outer surfaces.

[0237] Figure 8The first output gear 50 connected to the second output gear 52 and the second output gear 52 engaged with the drive wheel 8 are shown. Power is transmitted from the first output gear 50 to the second output gear 52, and these gears 50, 52 can have various gear ratios to maintain the same torque and speed, increase torque while reducing speed, or reduce torque while increasing speed. Next, the second output gear 52 transmits power to the drive wheel 8. In the depicted embodiment, the drive wheel 8 is attached to a portion of the second output gear 52 and fixed by a clip. However, it should be understood that the present disclosure encompasses embodiments in which the drive wheel 8 is attached to a portion of the second output gear 52 in another manner, and embodiments in which the drive wheel 8 and the second output gear 52 are a single component. The second output gear 52 and the drive wheel 8 are positioned around the crankshaft and are rotatable about the crankshaft axis, which is consistent with the typical position of the drive wheel 8 in prior art bicycles. The drive wheel 8 engages a chain to drive the rear hub of the bicycle for propulsion. Alternatively, instead of the gears 50, 52, a belt, such as a timing belt, can transmit power. Additionally or alternatively, instead of the drive wheel and the chain, a belt system can be used to drive the rear hub and / or the rear bicycle wheel.

[0238] Figure 9 A schematic diagram showing the controller 94 and other components, the controller 94 and other components communicate with each other to operate the transmission. The input end 92 can transmit an input signal to the controller 94, where the input signal is analyzed, and based on the analysis result, the controller 94 allows the battery 96 to supply power to the position motor 46 to establish the speed ratio of the transmission.

[0239] The input end 92 can be various devices, and some embodiments of the present disclosure can have multiple input ends 92. In one embodiment, the input end 92 is a shifter, such as a gear shifter on a bicycle. Thus, in various embodiments, the user can move a dial or paddle on the input end shifter 92 to select the speed ratio. The physical movement of the dial or paddle is detected by a sensor of the input end shifter 92, and the sensor sends an input signal to the controller 94. In some embodiments, the user selects from a limited number of speed ratios to keep the system familiar to users of prior art bicycles. In various embodiments, the user selects from an infinite number of possible speed ratios. The input signal or other signals can be transmitted via a wired connection or a wireless connection.

[0240] Based on the input signal, the controller 94 changes the amount of electric power supplied from the battery 96 to the position motor 46. Additionally, based on the input signal, the controller 94 can simultaneously transmit an output signal to the position motor 46 to indicate the operation of the position motor 46, such as the rotation direction of the output shaft, the rotation speed and acceleration of the output shaft, etc.

[0241] Another possible input 92 is a torque sensor that engages, for example, a crankshaft and a drive wheel or a component (such as a second output gear) connected to the drive wheel. When a user applies force to the pedal and the crankshaft, a torque is exerted on the crankshaft relative to the drive wheel. In some cases, the user applies less torque or no torque when going downhill. In contrast, in other cases, the user applies more torque when going uphill, and the user applies a considerable amount of force. The torque sensor transmits an input signal to the controller 94, and based on the input signal, the controller 94 can decide whether to take further action. The further action may include changing the amount of electrical power supplied from the battery 96 to the position motor 46 and other actions described herein, such as transmitting an output signal to the position motor 46 to, for example, reduce the speed ratio to assist the user's considerable force. The torque sensor (input 92) can also convey information about the rotational speed of the crankshaft and / or the drive wheel. In other embodiments, a separate cadence sensor or speed sensor can be used as another input 92 to the controller 94. The input 92 can be any sensor that detects the characteristics of the transmission or the environment around the transmission or user input.

[0242] In addition, in various embodiments, the transmission operates in conjunction with other components (such as, in the case of an electric bicycle or an electric vehicle, an electric motor 98). An electric motor is used in an electric vehicle to assist the user in different situations (including pedaling uphill or starting from a stationary position). For a similar purpose of assisting the user in applying force, the present disclosure encompasses embodiments that combine the transmission as described herein with the electric motor 98.

[0243] In some embodiments, the user input and / or the input from a sensor (such as a torque sensor) is transmitted to the controller 94 in the form of an input signal. Based on the input signal, the controller 94 instructs the position motor 46 of the transmission and / or the electric motor 98 to assist the user in applying force. In some embodiments, this may include changing the speed ratio of the transmission set by the position motor 46 and causing the electric motor to generate torque that helps propel the vehicle. In various embodiments, a generator and / or a regenerative braking device located at the wheel can charge the battery 96 on the bicycle.

[0244] Figure 10 A perspective view of a transmission 100 for a vehicle such as a bicycle is shown. Most of the components of the transmission 100 are housed within a protective housing 102 that prevents dust and other elements from contaminating the components of the transmission 100. A crankshaft 104 extends from the housing 102, and the user rotates the pedal and the crank arm to rotate the crankshaft 104, which inputs mechanical power into the transmission 100. InFigure 10 Also shown is line B-B.

[0245] Figure 11 Shows a bottom view cross-section of the transmission 100 taken along Figure 10 line B-B in. The housing 102 includes a first portion 106 on a first side 107 of the transmission 100, and the first portion 106 is coupled to a second portion 108 on a second side 109 of the transmission 100. The terms "first side" and "second side" are relative and may be used the other way around or replaced with other relative terms.

[0246] The crankshaft 104 is rotatable about a crankshaft axis 110 to provide a mechanical power input to the transmission 100. When the crankshaft 104 rotates, power is first transmitted through a drive assembly 122 (in this case, the drive assembly 122 may be referred to as a drive gear assembly 122) to increase speed and decrease torque at the belt 146 of the transmission 100. The increase in speed causes a faster and more sensitive change in the speed ratio, and the decrease in torque means less wear on the belt 146 and surrounding components. The drive gear assembly 122 includes a first gear 124 that is coupled to and positioned about the crankshaft 104. Teeth on an outer surface of the first gear 124 operably engage teeth on an outer surface of a second gear 126 that is coupled to and positioned about an intermediate shaft 112. The intermediate shaft 112 is rotatable about an intermediate axis 114. Then, a third gear 128 is coupled to and positioned about the intermediate shaft 112. Teeth on an outer surface of the third gear 128 operably engage teeth on an outer surface of a fourth gear 130 that is coupled to and positioned about a countershaft 116. The countershaft 116 is rotatable about a countershaft axis 118.

[0247] In this drive gear assembly 122, the second gear 126 has fewer teeth than the first gear 124, the fourth gear 130 has fewer teeth than the third gear 128, and the second and third gears 126, 128 rotate together with the intermediate shaft 112. Thus, the drive gear assembly 122 causes the countershaft 116 to rotate at a greater speed and with less torque than the crankshaft 104. If the overall gear ratio of the drive gear assembly 122 is too low, then the reduction in torque is insufficient, and the sheave and belt are subjected to greater forces, wear, and tear. If the overall gear ratio is too high, then the components of the transmission 100 may be subjected to excessive speeds, which reduces the efficiency of components such as bearings and other moving parts. Thus, in some embodiments, the overall gear ratio of the drive gear assembly 122 is between approximately 1:3.8 and 1:14.5. In various embodiments, the overall gear ratio of the drive gear assembly 122 is approximately 1:9.

[0248] It should be understood that other drive components 122 may be substituted Figure 11 for the drive gear assembly 122 in Figure 2B . For example, a series of planetary gear sets ( Figure 11 26, 28 in

[0249] ) may be used as the drive component 122 in . The drive component 122 may be located in a lubricant-containing sealed portion of the housing 102. The terms "drive component" or "driven component" may encompass gear assemblies and other components that do not have gears but otherwise change the speed and torque of a rotating member. Next, the countershaft 116 transmits power to the fixed drive sheave 132 and the movable drive sheave 134 to rotate the belt 146. The fixed drive sheave 132 is rotatable about the countershaft axis 118 but does not move along the countershaft axis 118, while the movable drive sheave 134 is rotatable about the countershaft axis 118 and is movable along the countershaft axis 118. The position of the movable drive sheave 134 along the countershaft axis 118 is set by the position motor 136, and the position of the movable drive sheave 134 along the countershaft axis 118 sets the speed ratio of the transmission 100. When the distance between the drive sheaves 132, 134 is relatively large, the belt 146 is relatively low in the drive sheaves 132, 134, and the final output of the transmission 100 is a larger speed and a smaller torque. Conversely, when the distance between the drive sheaves 132, 134 is relatively small, the belt 146 is relatively high in the drive sheaves 132, 134, and the final output of the transmission 100 is a relatively smaller speed and a larger torque.

[0250] The position motor 136 sets the position of the movable drive sheave 134 along the countershaft axis 118 by rotating the output shaft 142 disposed in the cam eccentric 144. The cam eccentric 144 is in turn disposed in a groove of the hub 140. As will be described in further detail with respect to Figure 13 , the cam eccentric 144 and the hub 140 convert the rotational motion of the output shaft 142 into a linear motion of the movable drive sheave 134 along the countershaft axis 118.

[0251] At the other end of belt 146 are a movable driven sheave 150 and a fixed driven sheave 148. The movable driven sheave 150 and the fixed driven sheave 148 are positioned about the crankshaft 104 and receive power from the belt 146. A biasing member 152 applies a force on the movable driven sheave 150 in a linear or non-linear response such that the movable driven sheave 150 can move along the crankshaft axis 110 to accommodate the movement of the belt 146 as indicated by the drive sheaves 132, 134 and the positioning motor 136. The driven sheaves 148, 150 transmit power to a driven assembly 154, which in this case may be referred to as a driven gear assembly 154, that increases the torque of the drive wheel 120 and decreases its speed.

[0252] To accommodate the setting of the speed ratio and the up and down movement of the belt 146 among the sheaves 132, 134, 148, 150, the movable drive sheave 134 and the movable driven sheave 150 are positioned on opposite sides of the belt 146. In other words, the movable drive sheave 134 is positioned between the first side of the housing 102 and the fixed drive sheave 132, and the movable driven sheave 150 is positioned between the second side of the housing 102 and the fixed driven sheave 148. This arrangement provides stability to the belt 146 while changing the speed ratio.

[0253] In this embodiment, the driven gear assembly 154 includes a sun gear 156 that receives power from the driven sheaves 148, 150, a plurality of planet gears 158 that receive power from the sun gear 156, a fixed ring gear 162 within which the planet gears 158 rotate, and a carrier 160 that couples the planet gears 158. The carrier 160 transmits power from the planet gears 158 to the drive wheel 120. Generally, the driven gear assembly 154 transmits power to decrease the speed and increase the torque at the drive wheel 120. In some embodiments, the overall gear ratio of the driven gear assembly 154 is between approximately 3:1 and 4.5:1. In various embodiments, the overall gear ratio of the driven gear assembly 154 is between 3.8:1 and 4:1. The driven assembly 154 may be positioned in a sealed portion of the housing 102 that contains lubricant. As previously mentioned, different driven assemblies may replace one another. Additionally, the driven assembly is optional, where some embodiments of the present disclosure do not include a driven assembly. Instead, the driven sheaves 148, 150 provide power to the output of the transmission 100, which rotates at the same speed and torque as the driven sheaves 148, 150.

[0254] Figure 12 Shown Figure 11Stereogram of the drive gear assembly 122 in []. The first gear 124 transmits power from the crankshaft 104 to the second gear 126 and the intermediate shaft 112. Then, the intermediate shaft 112 and the third gear 128 transmit power to the fourth gear 130 and the countershaft 116. As a result, the countershaft 116 rotates at a greater speed and with less torque than the crankshaft 104.

[0255] Figure 13 Stereogram showing the position motor 136 and the drive sheaves 132, 134. The output shaft 142 of the position motor 136 is positioned within the cam eccentric 144. In other words, the axis of rotation of the output shaft 142 is offset from the center of the cam eccentric 144. When the position motor 136 receives an input and causes the output shaft 142 and the cam eccentric 144 to rotate, the cam eccentric 144 also moves along the countershaft axis 118 of the countershaft 116. The cam eccentric 144 is positioned within a groove 168 of the hub 140, and the hub 140 is restricted to move along the countershaft axis 118. Thus, when the cam eccentric 144 moves along the countershaft axis 118, the hub 140 moves along the countershaft axis 118, and the movable drive sheave 134 moves along the countershaft axis 118 to set the speed ratio of the transmission. The position motor 136 can receive inputs from various components (such as those described with respect to Figure 9 ), to cause the output shaft 142 to rotate to different rotational positions at different speeds, accelerations, etc.

[0256] The fixed drive sheave 132 can be directly coupled to the countershaft 116 to receive power from the countershaft 116. Additionally, the countershaft 116 can have pins extending outwardly that extend into slots of the movable drive sheave 134, similar to Figure 5 the countershaft (38) and the movable driven sheave (44) in []. Each slot extends along a line that is not parallel to the countershaft axis 118. The angle and orientation of the slots balance multiple functions, which include effectively transmitting power from the countershaft 116 to the movable drive sheave 134, reducing the force required to move the movable drive sheave 134 along the countershaft axis 118, and preventing the belt from slipping relative to the sheaves as the transmission continuously changes between speed ratios. Further, the position motor 136 is positioned adjacent to the movable drive sheave 134, which reduces the complexity of the components that transfer the movement of the output shaft 142 to the movable drive sheave 134.

[0257] Figure 14 Stereogram showing the fixed driven sheave 148 that is rotatable about the crankshaft 104. Here, the movable driven sheave ( Figure 11within 150), but the movable driven sheave is connected to a movable collar 174 having one or more slots 176. The movable driven sheave and the movable collar 174 may be a single component and / or collectively referred to as the movable driven sheave. Each slot 176 has an axis 177 that is not parallel to the crankshaft axis 110. The fixed driven sheave 148 is connected to a fixed collar 170 having one or more pins 172 that extend outwardly into corresponding slots 176. The fixed driven sheave 148 and the fixed collar 170 may be a single component and / or collectively referred to as the fixed driven sheave 148. In this embodiment, the plurality of slots 176 and the plurality of pins 172 are evenly spaced about the crankshaft axis 110. However, it should be understood that the spacing may be uneven, and / or the number of slots 176 and pins 172 may be any number.

[0258] The angle and orientation of the slots 176 balance multiple functions, including effectively transmitting power from the driven sheave to the driven assembly, reducing the force required to move the movable driven sheave along the crankshaft axis 110, and preventing the belt from slipping relative to the sheave as the transmission continuously changes between speed ratios. Specifically, the power received by the driven sheave is transmitted to the collars 170, 174, and the fixed collar 170 transmits the power to the sun gear of the driven assembly described herein ( Figure 15 of 156).

[0259] In some embodiments, the angle formed by the axis 177 of the slot 176 and the crankshaft axis 110 may be between about 5 degrees and 50 degrees. In various embodiments, the angle is about 20 degrees. In some embodiments, the angle between the axis of the slot in the movable drive sheave 134 and the secondary axis 118 may be between about 5 degrees and 50 degrees. In various embodiments, the angle is about 20 degrees. To support the requirements of the written description, U.S. Patent Application No. 18 / 126,653 and U.S. Patent Application No. 13 / 328,630 are hereby incorporated by reference in their entireties.

[0260] Figure 15 A perspective view showing the driven gear assembly 154 positioned around the crankshaft 104. The sun gear 156 receives power from the driven sheave, particularly the fixed collar ( Figure 14 within 170). The sun gear 156 then drives the four planet gears 158 against the fixed ring gear 162. The carrier 160 couples the planet gears 158 and transmits the power to the drive wheel ( Figure 11 within 120). The driven gear assembly 154 transmits power to the drive wheel such that the drive wheel rotates at a greater torque and a lower speed than the driven sheave. Then, in the case of a bicycle, the drive wheel transmits the power to the rear hub and the rear wheel.

[0261] Figure 16 A perspective view of a transmission 178 with a housing 180 is shown, where the transmission 178 transmits power for a vehicle such as a bicycle. Figure 17 Shown Figure 16 A cross-sectional view of the transmission 178 taken along line C-C in. The crankshaft 182 is rotatable about a crankshaft axis 184, and the crankshaft 182 rotates a drive assembly 192, in which case the drive assembly 192 may be referred to as a drive gear assembly 192. Specifically, the drive gear assembly 192 is a series of planetary gear sets, similar to Figure 2B the transmission in. The output of the drive gear assembly 192 rotates a fixed drive sheave 194 and a movable drive sheave 196, and the movable drive sheave 196 is passively biased by a biasing member 198 in a linear or non-linear response. The drive sheaves 194, 196 rotate a belt 200, and the belt 200 rotates a fixed driven sheave 202 and a movable driven sheave 204. A position motor 206 indicates the position of the movable driven sheave 204, and the position sets the speed ratio of the transmission. The driven sheaves 202, 204 rotate a countershaft 186 about a countershaft axis 188. The countershaft 186 rotates a driven assembly 208, which in this case may be referred to as a driven sprocket assembly 208, and the driven sprocket assembly 208 transmits power to a drive wheel 190 and to, for example, the rear hub and rear wheel of a bicycle.

[0262] Figure 18 Shown Figure 16 A perspective view of the driven sprocket assembly 208 of the transmission 178 in. The driven sprocket assembly 208 includes a drive sprocket 210 positioned around the countershaft 186, a driven sprocket 214 positioned around the crankshaft 182, and a timing belt 212 coupling the sprockets 210, 214. Thus, the countershaft 186 rotates the drive sprocket 210, and the drive sprocket 210 rotates the belt 212, the driven sprocket 214, and the drive wheel 190. Since the drive sprocket 210 has fewer teeth than the driven sprocket 214, the drive wheel 190 rotates at a lower speed and with a greater torque than the countershaft 186. In this embodiment, the use of sprockets 210, 214 and a belt 212 eliminates the need for lubricated sealed portions of the housing, as opposed to a drive assembly or a driven assembly having gears that engage with gears.

[0263] Generally, it should be understood that, without departing from the scope of the present disclosure, the various components described herein may be replaced and used in other embodiments described herein. For example, Figure 18 the driven assembly 208 described in Figure 1 or 10 may be used in the transmission described in

[0264] Although various embodiments of the present disclosure have been described in detail, it will be apparent to those skilled in the art that modifications and variations of these embodiments will occur to them. However, it should be clearly understood that such modifications and variations are within the scope and spirit of the present disclosure as set forth in the appended claims. Further, the inventions described herein can have other embodiments and can be practiced or carried out in various ways. It should be understood that the language and terminology used herein are for the purpose of description and should not be regarded as limiting.

Claims

1. A continuously variable transmission for a bicycle, comprising: A crankshaft rotatable about a crankshaft axis; A countershaft rotatable about a counter axis; A drive assembly having an input end engaged with the crankshaft and an output end engaged with the countershaft, wherein the crankshaft drives the drive assembly, and the drive assembly drives the countershaft such that the countershaft rotates at a greater speed and a smaller torque than the crankshaft; A set of drive sheaves positioned around the countershaft and engaged with the countershaft; A set of driven sheaves positioned around the crankshaft; A belt coupling the set of drive sheaves and the set of driven sheaves and configured to transmit power from the set of drive sheaves to the set of driven sheaves, wherein the speed ratio between the set of drive sheaves and the set of driven sheaves is continuously variable; And A driven assembly positioned around the crankshaft, wherein an input end of the driven assembly is engaged with the set of driven sheaves, an output end of the driven assembly is configured to rotate at a smaller speed and a greater torque than the set of driven sheaves, and an output end of the driven assembly is configured to transmit power to propel the bicycle.

2. The continuously variable transmission according to claim 1, further comprising a position motor, wherein the set of drive sheaves comprises: A fixed sheave; And A movable sheave engaged with the position motor, wherein the position motor is configured to move the movable sheave along the counter axis to change the speed ratio between the set of drive sheaves and the set of driven sheaves.

3. The continuously variable transmission according to claim 1, further comprising a biasing member, wherein the set of driven sheaves comprises: A fixed sheave; And A movable sheave, wherein the biasing member is configured to act on the movable sheave along the crankshaft axis, and the movable sheave is configured to change its position along the crankshaft axis to accommodate the speed ratio established by the set of drive sheaves.

4. The continuously variable transmission according to claim 1, wherein, The drive assembly comprises: A first gear positioned around the crankshaft and serving as the input end of the drive assembly, and a second gear positioned around an intermediate shaft and engaged with the intermediate shaft, wherein the crankshaft drives the first gear, and the first gear drives the second gear such that the intermediate shaft rotates at a greater speed and a smaller torque than the crankshaft; and A third gear positioned around the intermediate shaft and engaged with the intermediate shaft, and a fourth gear positioned around the countershaft and serving as the output end of the drive assembly, wherein the intermediate shaft drives the third gear, and the third gear drives the fourth gear such that the countershaft rotates at a greater speed and a smaller torque than the intermediate shaft.

5. The continuously variable transmission according to claim 4, wherein, The gear ratio between the input end and the output end of the drive assembly is between approximately 1:3.8 and 1:14.

5.

6. The continuously variable transmission according to claim 1, wherein, The driven assembly comprises: A planetary gear set having a ring gear, a plurality of planet gears, a carrier coupling the plurality of planet gears, and a sun gear, wherein the sun gear is an input end of the driven assembly, wherein the sun gear is configured to drive the plurality of planet gears against the ring gear such that the carrier rotates at a lower speed and a greater torque than the sun gear, and wherein the carrier is an output end of the driven assembly.

7. The continuously variable transmission according to claim 1, wherein, The driven assembly includes: a first sprocket as an input end of the driven assembly, and a second sprocket as an output end of the driven assembly; and a belt coupling the first sprocket and the second sprocket.

8. A continuously variable transmission system for a bicycle, comprising: a crankshaft rotatable about a crankshaft axis; a countershaft rotatable about a countershaft axis; a fixed drive pulley and a movable drive pulley positioned around the countershaft, wherein the fixed drive pulley and the movable drive pulley are configured to receive power from the countershaft; a fixed driven pulley and a movable driven pulley positioned around the crankshaft; a belt coupling the fixed drive pulley and the movable drive pulley to the fixed driven pulley and the movable driven pulley, wherein the belt is configured to transmit power from the fixed drive pulley and the movable drive pulley to the fixed driven pulley and the movable driven pulley, and wherein the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley is continuously variable; a biasing member configured to act on the movable driven pulley along the crankshaft axis, wherein the movable driven pulley changes position along the crankshaft axis to accommodate the speed ratio established by the fixed drive pulley and the movable drive pulley; and a position motor engaged with the movable drive pulley, wherein the position motor is configured to move the movable drive pulley along the countershaft axis to change the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley.

9. The continuously variable transmission system according to claim 8, wherein, The position motor is a servo motor having an output shaft, and rotation of the output shaft moves the movable drive pulley along the countershaft axis.

10. The continuously variable transmission system according to claim 9, further comprising: an eccentric cam connected to the output shaft of the servo motor; and a hub configured to move along the countershaft axis, wherein the eccentric cam extends into a groove of the hub, and rotation of the output shaft causes the eccentric cam to rotate and causes the hub to move the movable drive pulley along the countershaft axis, which changes the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley.

11. The continuously variable transmission system according to claim 8, further comprising: A controller in communication with the position motor; and A shifter in communication with the controller, wherein the shifter is configured to transmit an input signal to the controller, and the controller is configured to cause the position motor to move the movable drive sheave along the secondary axis to change the speed ratio between the fixed drive sheave and the movable drive sheave and the fixed driven sheave and the movable driven sheave.

12. The continuously variable transmission system according to claim 8, further comprising: A controller in communication with the position motor; and A torque sensor operably engaged with the crankshaft and in communication with the controller, wherein the torque sensor is configured to transmit an input signal to the controller, and the controller is configured to cause the position motor to move the movable drive sheave along the secondary axis to change the speed ratio between the fixed drive sheave and the movable drive sheave and the fixed driven sheave and the movable driven sheave.

13. The continuously variable transmission system according to claim 8, further comprising: A drive assembly having an input end engaged with the crankshaft and an output end engaged with the secondary shaft, wherein the crankshaft drives the drive assembly, and the drive assembly drives the secondary shaft such that the secondary shaft rotates at a greater speed and a smaller torque than the crankshaft; and A driven assembly positioned around the crankshaft, wherein an input end of the driven assembly is engaged with the fixed driven sheave and the movable driven sheave, wherein an output end of the driven assembly is configured to rotate at a smaller speed and a greater torque than the fixed driven sheave and the movable driven sheave, and wherein the output end of the driven assembly is configured to transmit power to propel the bicycle.

14. The continuously variable transmission system according to claim 8, wherein, The biasing member is a spring that produces either a linear change force or a non-linear change force in response to displacement.

15. A continuously variable transmission for a bicycle, comprising: A housing extending from a first side to a second side; A crankshaft rotatable about a crankshaft axis, wherein the crankshaft is at least partially positioned within the housing; A secondary shaft rotatable about a secondary axis, wherein the secondary shaft is positioned within the housing; A fixed drive sheave and a movable drive sheave positioned around the secondary shaft, wherein the fixed drive sheave and the movable drive sheave are positioned within the housing, and the movable drive sheave is positioned between the fixed drive sheave and the first side of the housing, wherein the fixed drive sheave and the movable drive sheave are configured to receive power from the secondary shaft; A fixed driven sheave and a movable driven sheave positioned around the crankshaft, wherein the fixed driven sheave and the movable driven sheave are positioned within the housing, and the movable driven sheave is positioned between the fixed driven sheave and the second side of the housing; a belt configured to transmit power from the fixed drive pulley and the movable drive pulley to the fixed driven pulley and the movable driven pulley, and wherein the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley is continuously variable; and a position motor positioned between the movable drive pulley and a first side of the housing, wherein the position motor is configured to move the movable drive pulley along the secondary axis to change the speed ratio between the fixed drive pulley and the movable drive pulley and the fixed driven pulley and the movable driven pulley.

16. The continuously variable transmission according to claim 15, further comprising: a biasing member configured to act on the movable driven pulley along the crankshaft axis, wherein the biasing member is positioned between the movable driven pulley and a second side of the housing, and the movable driven pulley changes position along the crankshaft axis to accommodate the speed ratio established by the fixed drive pulley and the movable drive pulley.

17. The continuously variable transmission according to claim 15, further comprising: a fixed collar positioned around the crankshaft, wherein the fixed driven pulley engages with the fixed collar; a movable collar positioned around the fixed collar, wherein the movable driven pulley engages with the movable collar; a plurality of pins extending from the fixed collar into respective slots of the movable collar such that the movable collar and the movable driven pulley are configured to transmit power to the fixed collar and move along the crankshaft axis.

18. The continuously variable transmission according to claim 15, further comprising: a drive assembly positioned between a second side of the housing and the fixed drive pulley, wherein the drive assembly is configured to transmit power from the crankshaft to the secondary shaft such that the secondary shaft rotates at a greater speed and a smaller torque than the crankshaft; and a driven assembly positioned around the crankshaft between a first side of the housing and the fixed driven pulley, wherein the driven assembly is configured to transmit power from the fixed driven pulley and the movable driven pulley to a drive wheel such that the drive wheel rotates at a smaller speed and a greater torque than the fixed driven pulley and the movable driven pulley.

19. The continuously variable transmission according to claim 18, wherein, The drive assembly is positioned in a first sealed portion of the housing configured to receive lubricant, and the driven assembly is positioned in a second sealed portion of the housing configured to receive lubricant.

20. The continuously variable transmission according to claim 15, wherein, The belt has a V-shaped cross-section, and the inner surfaces of the fixed drive pulley and the movable drive pulley and the inner surfaces of the fixed driven pulley and the movable driven pulley are tapered to complement the side surfaces of the V-shaped belt.

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