Continuously variable transmission for an electric bicycle

Abstract

A compact-size CVT in a mid-drive motor package for an electric bicycle includes a generator subassembly with a generator motor and an optional generator gearbox, and a traction subassembly with a traction motor and an optional traction gearbox. The generator subassembly receives user input from a crankshaft and converts to electrical power. The traction subassembly receives electrical power and converts to output power or torque for an output sprocket. The components of the generator subassembly and the traction subassembly are coaxial along a longitudinal axis through the crankshaft, which is insertable through the generator subassembly and the traction subassembly, to increase the compactness of the CVT. Controlled power output by the shifting and traction motors allows for continuously variable transmission functionality with variable speed output, while reducing or eliminating dead zones and providing forward and reverse propulsion controls.

Description

[0001] Attorney Docket No. 11042-14-PCT

[0002] CONTINUOUSLY VARIABLE TRANSMISSION FOR AN ELECTRIC BICYCLE

[0003] CROSS-REFERENCE TO RELATED APPLICATION The present application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63 / 745,412, filed on January 15, 2025; the entirety of which is incorporated herein by reference.

[0004] FIELD

[0005] The disclosure relates to a transmission for an electric bicycle and, in particular, is directed to a continuously variable transmission for an electric bicycle in a compact middrive motor package.

[0006] BACKGROUND

[0007] In the electric bicycle (or E-bike) industry, continuously variable transmission (CVT) technology presents challenges due to the unique constraints of electric bicycles. Typically, achieving a desired reducer ratio in a transmission for an electric bicycle requires multiple gear systems, each including shaft spur gear systems and / or planetary gear systems, resulting in larger packaging sizes. This increases the cost and complexity of the transmission, and increases the weight of the electric bicycle to which the electric transmission is coupled.

[0008] Previous attempts to adapt the automatic CVT mechanism from cars to electric bicycles have faced several disadvantages. For example, one major drawback is that CVT technology is traditionally designed to operate most efficiently at high speeds, while bikes typically operate at lower speeds. This requires a CVT installed on an electric bicycle to increase speed first to reach optimal efficiency, before decreasing the speed for the electric bicycle to achieve the desired continuous shifting operation. One method to offset this requirement is the incorporation of numerous gear sets within the CVT, which results in a larger overall size. In addition, when considering the desired speed ratio for the electric bicycle, a typical CVT may require multiple shafts of spur gear systems or multiple levels of planetary gear systems to output the necessary ratio if a motor were used to drive the electric bicycle, similarly increasing the packaging size of the CVT.

[0009] In addition, known CVT technology may have dead zones in a range that is near zero rotations per minute (RPM). Controlling the CVT in a range near zero is difficult and sometimes not possible, such that the electric bicycle does not operate as intended. One option is to remove or skip over the dead zone range, but that may reduce the overallAttorney Docket No. 11042-14-PCT

[0010] operation of the electric bicycle and provide an undesirable ride for a user. Another option is to change gear ratios to remove the dead zone, but this may require higher speeds that a motor coupled to the CVT may be capable of.

[0011] As such, known CVT technology in electric bicycles involves complex arrangements of gear sets and a large packaging size. In addition, known CVT technology in electric bicycles requires additional shafts or gear systems to achieve the desired speed ratio, further increasing the packaging size. Further, known CVT technology in electric bicycles may have dead zones within the range of zero RPM, which may increase the difficulty of operation of the electric bicycle.

[0012] SUMMARY

[0013] As such, there exists a need for a CVT for an e-bike that is compact in size and that does not have dead zones. Embodiments of the present disclosure are directed to a compactsize CVT for an electric bicycle in a mid-drive motor package. The present disclosure addresses the above issues by employing a generator subassembly that receives a user input from a crankshaft and a traction subassembly that provides output power (e.g., a torque) to an output sprocket (or other ring output). The combination of the generator subassembly and the traction subassembly, in addition to optional controllers and / or battery packs, result in continuous speed variation to provide electric bicycles with CVT technology.

[0014] It is one aspect of the embodiments of the present disclosure to provide an axial flux motor within the mid-drive motor package. Use of an axial flux motor allows for a feasible and efficient packaging solution, enabling the successful implementation of CVT technology in electric bicycles. In some embodiments, the axial flux motor includes a center hollow design, allowing for placement directly on an axle or crankshaft without the need for multiple shafts, creating compact packaging and making it more space-efficient. In some embodiments, the generator subassembly includes a generator motor and the traction subassembly includes a traction motor.

[0015] It is another aspect of embodiments of the present disclosure to provide planetary gearboxes in the CVT. In some embodiments, planetary generator and traction gearboxes include a center hollow design through the respective planet carriers, allowing for placement directly on an axle or crankshaft without the need for multiple shafts (e.g., and optionally axially-aligned with the axial flux generator and traction motors), creating compact packaging and making it more space-efficient.Attorney Docket No. 11042-14-PCT

[0016] Embodiments of the present disclosure are directed to a CVT. The CVT has a generator subassembly and a traction subassembly. The generator subassembly receives and converts user input from a crankshaft into electrical power. The traction subassembly receives and converts electrical power into output power for an output sprocket.

[0017] The CVT includes the generator subassembly with a generator motor that converts kinetic energy from user input to electrical power, which is provided to a controller, a battery pack, and / or the traction subassembly. In some embodiments, the generator subassembly includes a planetary generator gearbox with a first ring gear that receives the user input from a crankshaft, a second ring gear that is fixed, and a first set of planet gears and a second set of planet gears that are coupled to a planet carrier. Rotation of the first ring gear causes rotation of the planet carrier, which transfers the kinetic energy from the user input to, and causes rotation of, the generator motor to produce electrical power.

[0018] The CVT additionally includes the traction subassembly with a traction motor that receives electrical power from the controller, the battery pack, and / or the generator subassembly and converts the electrical power into output power (e.g., a torque) to the output sprocket. In some embodiments, the traction subassembly includes a planetary traction gearbox with a first ring gear that is fixed, a second ring gear that provides an output power, and a first set of planet gears and a second set of planet gears that are coupled to a planet carrier. The traction motor receives electrical power, and converts the electrical power into rotational kinetic energy. Rotation of the planet carrier with the kinetic energy causes rotation of the second ring gear, which produces output power (e.g., a torque) for the output sprocket.

[0019] The generator subassembly converts user input into electrical power, and the traction subassembly converts electrical power into output power (e.g., a torque) as a variable speed output through an output sprocket. The conversion to and from electrical power, by decoupling the crankshaft and the generator subassembly from the output sprocket and instead transferring kinetic energy through the generator subassembly and outputting a torque from the traction subassembly, enables continuous variation of the speed output. In this regard, the CVT of the present disclosure offers versatility and control over the reducer speed ratio, enhancing the overall performance and efficiency of the electric bicycle with reducing or eliminating dead zones. In addition, the CVT of the present disclosure provides the option for both forward and backward propulsion by controlling the rotation of theAttorney Docket No. 11042-14-PCT

[0020] traction subassembly to rotate either in a forward or a reverse direction, propelling the electric bicycle in either a forward or a reverse direction.

[0021] It is a further aspect of embodiments of the present disclosure to provide an electric bicycle. The electric bicycle includes a mid-drive motor package with a generator subassembly and a traction subassembly. The mid-drive motor package is in communication with a hub of a wheel via a belt or chain. The electric bicycle includes a battery pack for powering the mid-drive motor package. The electric bicycle includes a control system operable to monitor and / or control one or more aspects of the electric bicycle, including battery pack input / output, generator motor input / output, and / or traction motor input / output.

[0022] A first aspect of the present disclosure is to provide a continuously variable transmission of a mid-drive motor package. The continuously variable transmission includes a generator subassembly comprising a generator motor, wherein the generator motor is configured to receive a mechanical power input from a crankshaft of the mid-drive motor package and is configured to produce an electrical power output. The continuously variable transmission includes a traction subassembly comprising a traction motor, wherein the traction motor is configured to receive an electrical power input and is configured to produce a mechanical power output to drive an output sprocket of the mid-drive motor package. The generator subassembly and the crankshaft are mechanically uncoupled from the output sprocket. The traction subassembly is mechanically uncoupled from the crankshaft.

[0023] The continuously variable transmission of the first aspect may include, optionally, wherein a battery pack is configured to receive the electrical power output from the generator motor and is configured to store electrical energy, and wherein the battery pack is configured to produce the electrical power input to the traction motor.

[0024] The continuously variable transmission of the first aspect may include one or more of the previous embodiments and, optionally, wherein a controller is configured to regulate a charging process of the battery pack where the electrical power output is stored as electrical energy, and the controller is configured to regulate a discharging process where the electrical energy is released as the electrical power input to the traction motor.

[0025] The continuously variable transmission of the first aspect may include one or more of the previous embodiments and, optionally, wherein the electrical power input received by the traction motor causes the traction motor to rotate in a forward direction.Attorney Docket No. 11042-14-PCT

[0026] The continuously variable transmission of the first aspect may include one or more of the previous embodiments and, optionally, wherein the electrical power input received by the traction motor causes the traction motor to rotate in a reverse direction.

[0027] The continuously variable transmission of the first aspect may include one or more of the previous embodiments and, optionally, wherein the generator subassembly includes a generator gearbox that is configured to receive the mechanical power input at a first torque and is configured to transmit the mechanical power input at a second torque to the generator motor, and wherein the second torque is less than the first torque.

[0028] The continuously variable transmission of the first aspect may include one or more of the previous embodiments and, optionally, wherein the generator gearbox comprises a first ring gear that is configured to receive the mechanical power input at the first torque; a second ring gear that is fixed; a first set of planet gears that engage the first ring gear; a second set of planet gears that engage the second ring gear; and a planet carrier to which the first set of planet gears and the second set of planet gears are coupled. Rotation of the first ring gear is configured to cause the planet carrier to transmit the mechanical power input at the second torque for the generator motor.

[0029] The continuously variable transmission of the first aspect may include one or more of the previous embodiments and, optionally, wherein the traction subassembly includes a traction gearbox that is configured to receive the mechanical power output at a first torque from the traction motor and is configured to transmit the mechanical power output at a second torque to the output sprocket, wherein the second torque is greater than the first torque.

[0030] The continuously variable transmission of the first aspect may include one or more of the previous embodiments and, optionally, wherein the traction gearbox comprises a first ring gear that is fixed; a second ring gear that is configured to transmit mechanical power to the output sprocket; a first set of planet gears that engage the first ring gear; a second set of planet gears that engage the second ring gear; and a planet carrier to which the first set of planet gears and the second set of planet gears are coupled. Rotation of the planet carrier with the mechanical power output at the first torque causes the second ring gear to transmit the mechanical power output at the second torque to the output sprocket.

[0031] A second aspect of the present disclosure is to provide a mid-drive motor package. The mid-drive motor package includes a crankshaft able to receive a user input from a user; an output sprocket able to output an output torque; and a continuously variable transmission.Attorney Docket No. 11042-14-PCT

[0032] The continuously variable transmission includes a generator subassembly comprising a generator motor, wherein the generator motor receives the user input from the crankshaft and outputs a first amount of electrical power; and a traction subassembly comprising a traction motor, wherein the traction motor receives a second amount of electrical power and produces the output torque for the output sprocket. The generator subassembly and the crankshaft are mechanically uncoupled from the output sprocket, and wherein the traction subassembly is mechanically uncoupled from the crankshaft.

[0033] The mid-drive motor package of the second aspect may include, optionally, wherein the generator subassembly includes a generator gearbox that receives the user input from the crankshaft and converts input kinetic energy from the user input into an input torque for the generator motor, and wherein the generator motor uses the input torque to generate the first amount of electrical power.

[0034] The mid-drive motor package of the second aspect may include one or more of the previous embodiments and, optionally, wherein the generator gearbox comprises a first ring gear that receives the user input from the crankshaft; a second ring gear that is fixed; a first set of planet gears that engage the first ring gear; a second set of planet gears that engage the second ring gear; and a planet carrier to which the first set of planet gears and the second set of planet gears are coupled. Rotation of the planet carrier converts the input kinetic energy from the user input into the input torque for the generator motor.

[0035] The mid-drive motor package of the second aspect may include one or more of the previous embodiments and, optionally, wherein the traction motor uses the second amount of electrical power to generate output kinetic energy, and wherein the traction subassembly includes a traction gearbox that uses the output kinetic energy to generate the output torque for the output sprocket.

[0036] The mid-drive motor package of the second aspect may include one or more of the previous embodiments and, optionally, wherein the traction subassembly includes a traction gearbox. The traction gearbox comprises a first ring gear that is fixed; a second ring gear that provides the output torque to the output sprocket; a first set of planet gears that engage the first ring gear; a second set of planet gears that engage the second ring gear; and a planet carrier to which the first set of planet gears and the second set of planet gears are coupled. The output kinetic energy from the traction motor rotates the planet carrier to rotate and the second ring gear to produce the output torque for the output sprocket.Attorney Docket No. 11042-14-PCT

[0037] A third aspect of the present disclosure is to provide an electric bicycle. The electric bicycle includes a mid-drive motor package. The mid-drive motor package includes a crankshaft able to receive a user input from a user; an output sprocket able to output an output torque; and a continuously variable transmission configured to receive the user input from the crankshaft and configured to produce the output torque for the output sprocket. The crankshaft is mechanically uncoupled from the output sprocket.

[0038] The electric bicycle of the third aspect may include, optionally, wherein the continuously variable transmission includes a generator subassembly comprising a generator motor, wherein the generator motor receives the user input from the crankshaft and outputs a first amount of electrical power. The continuously variable transmission includes a traction subassembly comprising a traction motor, wherein the traction motor receives a second amount of electrical power and produces the output torque for the output sprocket. The generator subassembly is mechanically uncoupled from the output sprocket, and the traction subassembly is mechanically uncoupled from the crankshaft.

[0039] The electric bicycle of the third aspect may include one or more of the previous embodiments and, optionally, a battery pack, wherein the first amount of electrical power outputted by the generator motor is outputted to a battery pack of the electric bicycle, and wherein the second amount of electrical power received by the traction motor is received from the battery pack.

[0040] The electric bicycle of the third aspect may include one or more of the previous embodiments and, optionally, a controller, wherein the first amount of electrical power outputted by the generator motor is determined by a controller of the electric bicycle, and wherein the second amount of electrical power received by the traction motor is determined by the controller.

[0041] The electric bicycle of the third aspect may include one or more of the previous embodiments and, optionally, wherein the second amount of electrical power received by the traction motor is configured to propel the electric bicycle in a forward direction.

[0042] The electric bicycle of the third aspect may include one or more of the previous embodiments and, optionally, wherein the second amount of electrical power received by the traction motor is configured to propel the electric bicycle in a reverse direction.

[0043] A fourth aspect of the present disclosure is to provide a method. The method of the fourth aspect may include, but is not limited to, receiving a user input from a crankshaft with a generator subassembly of a mid-drive motor package; converting the user input intoAttorney Docket No. 11042-14-PCT

[0044] a first amount of electrical power with the generator subassembly; receiving a second amount of electrical power with a traction subassembly; and converting the second amount of electrical power with the traction subassembly to an output torque for an output sprocket.

[0045] A fifth aspect of the present disclosure is to provide a continuously variable transmission of a mid-drive motor package. The continuously variable transmission includes a generator subassembly comprising a generator motor, wherein the generator motor receives a user input from a crankshaft of the mid-drive motor package and outputs a first amount of electrical power. The continuous variable transmission includes a traction subassembly comprising a traction motor, wherein the traction motor receives a second amount of electrical power and produces an output torque for an output sprocket of the middrive motor package. The generator subassembly and the crankshaft are mechanically uncoupled from the output sprocket. The traction subassembly is mechanically uncoupled from the crankshaft.

[0046] The continuously variable transmission of the fifth embodiment may include, optionally, wherein the first amount of electrical power outputted by the generator motor is outputted to a battery pack, and wherein the second amount of electrical power received by the traction motor is received from the battery pack.

[0047] The continuously variable transmission of the fifth embodiment may include, optionally, wherein the first amount of electrical power outputted by the generator motor is determined by a controller, and wherein the second amount of electrical power received by the traction motor is determined by the controller.

[0048] The continuously variable transmission of the fifth embodiment may include, optionally, wherein the second amount of electrical power received by the traction motor causes the traction motor to rotate in a forward direction.

[0049] The continuously variable transmission of the fifth embodiment may include, optionally, wherein the second amount of electrical power received by the traction motor causes the traction motor to rotate in a reverse direction.

[0050] The continuously variable transmission of the fifth embodiment may include, optionally, wherein the generator subassembly includes a generator gearbox that receives the user input from the crankshaft and converts input kinetic energy from the user input into an input torque for the generator motor, and wherein the generator motor uses the input torque to generate the first amount of electrical power.Attorney Docket No. 11042-14-PCT

[0051] The continuously variable transmission of the fifth embodiment may include, optionally, wherein the generator gearbox comprises a first ring gear that receives the user input from the crankshaft; a second ring gear that is fixed; a first set of planet gears that engage the first ring gear; a second set of planet gears that engage the second ring gear; and a planet carrier to which the first set of planet gears and the second set of planet gears are coupled. Rotation of the planet carrier converts the input kinetic energy from the user input into the input torque for the generator motor.

[0052] The continuously variable transmission of the fifth embodiment may include, optionally, wherein the traction motor uses the second amount of electrical power to generate output kinetic energy, and wherein the traction subassembly includes a traction gearbox that uses the output kinetic energy to generate the output torque for the output sprocket.

[0053] The continuously variable transmission of the fifth embodiment may include, optionally, wherein the traction subassembly includes a traction gearbox, and wherein the traction gearbox comprises a first ring gear that is fixed; a second ring gear that provides the output torque to the output sprocket; a first set of planet gears that engage the first ring gear; a second set of planet gears that engage the second ring gear; and a planet carrier to which the first set of planet gears and the second set of planet gears are coupled. The output kinetic energy from the traction motor rotates the planet carrier to rotate and the second ring gear to produce the output torque for the output sprocket.

[0054] The phrases “at least one,” “one or more,” and “and / or,” as used herein, 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 A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.

[0055] Unless otherwise indicated, all numbers expressing quantities, dimensions, conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about” or “approximately”. As used herein, unless otherwise specified, the terms “about,” “approximately,” etc., when used in relation to numerical limitations or ranges, mean that the recited limitation or range may vary by up to 10%. By way of non-limiting example, “about 750” can mean as little as 675 or as much as 825, or any value therebetween. When used in relation to ratios or relationships between two or more numerical limitations or ranges, the terms “about,” “approximately,” etc. meanAttorney Docket No. 11042-14-PCT

[0056] that each of the limitations or ranges may vary by up to 10%; by way of non-limiting example, a statement that two quantities are “approximately equal” can mean that a ratio between the two quantities is as little as 0.9: 1.1 or as much as 1.1:0.9 (or any value therebetween), and a statement that a four-way ratio is “about 3:3: 1:1” can mean that the first number in the ratio can be any value of at least 4.5 and no more than 3.5, the second number in the ratio can be any value of at least 2.7 and no more than 3.3, and so on.

[0057] The use of “substantially” in the present disclosure, when referring to a measurable quantity (e.g., a diameter or other distance) and used for purposes of comparison, is intended to mean within 3% of the comparative quantity. The terms “substantially similar to,” “substantially the same as,” and “substantially equal to,” as used herein, should be interpreted as if explicitly reciting and encompassing the special case in which the items of comparison are “similar to,” “the same as” and “equal to,” respectively.

[0058] The term “a” or “an” entity, as used herein, refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein.

[0059] The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Accordingly, the terms “including,” “comprising,” or “having” and variations thereof can be used interchangeably herein. The use of “engaged with” and variations thereof herein is meant to encompass any direct or indirect connections between components.

[0060] It shall be understood that the term “means” as used herein shall be given its broadest possible interpretation in accordance with 35 U.S.C. § 112(f). Accordingly, a claim incorporating the term “means” shall cover all structures, materials, or acts set forth herein, and all of the equivalents thereof. Further, the structures, materials, or acts and the equivalents thereof shall include all those described in the summary of the invention, brief description of the drawings, detailed description, abstract, and claims themselves.

[0061] These and other advantages will be apparent from the disclosure of the invention(s) contained herein. The above-described embodiments, objectives, and configurations are neither complete nor exhaustive. The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present disclosure. Moreover, references made herein to “the present invention,” or aspects thereof should be understood to mean certain embodiments of the present invention / disclosure and should not necessarily be construed as limiting all embodiments to a particular description.Attorney Docket No. 11042-14-PCT

[0062] The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detailed Description, particularly when taken together with the drawings.

[0063] It is to be appreciated that any feature or aspect described herein can be claimed in combination with any other feature(s) or aspect(s) as described herein, regardless of whether the features or aspects come from the same described embodiment.

[0064] Any one or more aspects described herein can be combined with any other one or more aspects described herein. Any one or more features described herein can be combined with any other one or more features described herein. Any one or more embodiments described herein can be combined with any other one or more embodiments described herein.

[0065] BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Those of skill in the art will recognize that the following description is merely illustrative of the principles of the disclosure, which may be applied in various ways to provide many different alternative embodiments. This description is made for illustrating the general principles of the teachings of this disclosure and is not meant to limit the inventive concepts disclosed herein.

[0067] The accompanying drawings, which are incorporated in and constitute a part of the 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.

[0068] Fig. 1A illustrates a perspective view of a mid-drive motor package including a continuously variable transmission, a crankshaft, and an output sprocket within a housing, in accordance with one or more embodiments of the present disclosure;

[0069] Fig. IB illustrates a front plan view of the continuously variable transmission and the crankshaft of Fig. 1A;

[0070] Fig. 1C illustrates a schematic view of the continuously variable transmission and the crankshaft of Fig. IB;

[0071] Fig. ID illustrates a cross-section of the front plan view of the continuously variable transmission and the crankshaft of Fig. IB;Attorney Docket No. 11042-14-PCT

[0072] Fig. IE illustrates a cross-section of the front plan view of the continuously variable transmission and the crankshaft of Fig. IB;

[0073] Fig. 2 illustrates a flow diagram of a method or process for the operation and use of the mid-drive motor package of Fig. 1A, in accordance with one or more embodiments of the present disclosure; and

[0074] Fig. 3 illustrates an electric bicycle including the mid-drive motor package of Fig.

[0075] 1 A, in accordance with one or more embodiments of the present disclosure.

[0076] It should be understood that the drawings are not necessarily to scale, and various dimensions may be altered. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.

[0077] Reference Number Component

[0078] 100 Mid-Drive Motor Package

[0079] 102 Continuously Variable Transmission 104 Crankshaft

[0080] 105 Splines

[0081] 106 Output Sprocket

[0082] 108 Housing

[0083] 109 Electrical Connector

[0084] 110 Generator subassembly

[0085] 112 Generator gearbox

[0086] 114 Generator motor

[0087] 116 Traction subassembly

[0088] 118 Traction motor

[0089] 120 Traction gearbox

[0090] 122 Ring Gear

[0091] 124 Set of Planet Gears

[0092] 126 Set of Planet Gears

[0093] 128 Planet Carrier

[0094] 130 Ring Gear

[0095] 132 Clutch

[0096] 134 Ring GearAttorney Docket No. 11042-14-PCT

[0097] 136 Set of Planet Gears

[0098] 138 Set of Planet Gears

[0099] 140 Planet Carrier

[0100] 142 Ring Gear

[0101] 144 Output Shaft

[0102] 146 Controller

[0103] 148 Shaft

[0104] 150 Flange

[0105] 152 Axle

[0106] 154 Shaft

[0107] 156 Flange

[0108] 158 Axle

[0109] 162 Splines

[0110] 164 Generator Pathway

[0111] 166 Electrical Pathway

[0112] 168 Traction Pathway

[0113] 169 Disconnect

[0114] 200 Method or Process

[0115] 202 Receive User Input

[0116] 204 Convert User Input to Electrical Power 206 Receive Electrical Power

[0117] 208 Convert Electrical Power to Output Power 300 Electric Bicycle

[0118] 302 Belt or Chain

[0119] 304 Hub

[0120] 305 User Input

[0121] 306 Wheel

[0122] 307 Electrical Power

[0123] 308 Battery Pack

[0124] 309 Output Power

[0125] 310 Control System

[0126] 311 DataAttorney Docket No. 11042-14-PCT

[0127] DETAILED DESCRIPTION

[0128] Although the following text sets forth a detailed description of numerous different embodiments, it should be understood that the legal scope of the description is defined by the words 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 since describing every possible embodiment of a continuously variable transmission (CVT) for an electric bicycle would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims. Additionally, any combination of features shown in the various figures can be used to create additional embodiments of the present disclosure. Thus, dimensions, aspects, and features of one embodiment of the CVT can be combined with dimensions, aspects, and features of another embodiment of the CVT to create the claimed embodiment.

[0129] In general, embodiments of the present disclosure are directed to a compact-size CVT in a mid-drive motor package for an electric bicycle. Embodiments of the present disclosure are directed to planetary gear systems in the CVT. Embodiments of the present disclosure are also directed to axial flux motors in the CVT. Embodiments of the present disclosure include gear systems and motors that are each coaxial along a longitudinal axis through a crankshaft that is insertable through the planetary gear system and motors. Embodiments of the present disclosure are directed to a CVT that reduces or eliminates dead zones while maintaining CVT functionality.

[0130] To this effect, embodiments of the present disclosure are directed to a CVT that includes a generator subassembly able to receive a user input via a crankshaft, and a traction subassembly able to provide output power (e.g., a torque) for an output sprocket, where the generator subassembly converts kinetic energy from the user input into electrical power that is usable by the traction subassembly to produce the output power (e.g., a torque). Embodiments of the present disclosure are directed to a controller that monitors and regulates the electrical power output from the generator subassembly and to the traction subassembly, including with power storage into and / or power providing out of a battery or battery pack. Embodiments of the present disclosure include providing output power (e.g., a torque) that is modified user input power which is optionally supplemented with assist power (e.g., from the battery or battery pack).Attorney Docket No. 11042-14-PCT

[0131] Figs. 1 A-1E in general illustrate a mid-drive motor package 100, in accordance with one or more embodiments of the present disclosure.

[0132] The mid-drive motor package 100 includes a continuously variable transmission or CVT 102. The mid-drive motor package 100 also includes a crankshaft 104 with splines 105 (e.g., as illustrated in Fig. IB) that passes through and is in communication with the CVT 102. For example, the splines 105 may be configured to receive and / or otherwise engage with pedals installed on the crankshaft 104 (pedals not shown). It is noted, however, that the pedals may include a male coupler that inserts into an opening at each respective end of the crankshaft 104, which may be held in place via a fastener through the male coupler and into the opening, via an interference fit, via an interlocking assembly, via an adhesive, or some combination thereof without departing from the scope of the present disclosure.

[0133] The mid-drive motor package further includes an output sprocket 106 (or other ring output) in communication with the CVT 102 (e.g., as illustrated in Fig. IE). In some embodiments, the output sprocket 106 is a belt-drive sprocket that is operable to receive and power a belt coupled to a hub of a wheel of an electric bicycle (belt not shown). In some embodiments, the output sprocket 106 is a chain-drive sprocket that is operable to receive and power a chain coupled to a hub of a wheel of an electric bicycle (chain not shown).

[0134] At least a portion of the CVT 102, the crankshaft 104, and / or the output sprocket 106 may be positioned within a housing 108 of the mid-drive motor package 100. For example, the CVT 102 may be substantially positioned within the housing 108, the crankshaft 104 may pass through the housing 108, and the output sprocket 106 may be fully positioned external to, or have at least a portion positioned external to, the housing 108. It is noted that the housing 108 may be of a single-piece or integrated construction, or alternatively be of a multi-piece construction with separate and joined components, without departing from the scope of the present disclosure.

[0135] It is noted that the housing 108 is generally shown in Fig. IB, but that the housing 108 may be any shape or dimension to secure at least a portion of the CVT 102, the crankshaft 104, and / or the output sprocket 106 within the housing 108. For example, the housing 108 may be contoured to conform to one or more components of the CVT 102. In general, the housing 108 protects the CVT 102 components from water and / or particulates, while optionally retaining lubricant for the CVT 102 in an interior cavity defined within the housing 108.Attorney Docket No. 11042-14-PCT

[0136] In some embodiments, one or more electrical connectors 109 may be positioned within (or extend outward from) an exterior surface of the CVT 102. For example, the one or more electrical connectors 109 may provide power to a generator motor 114 and / or a traction motor 118, as described in detail further herein. By way of another example, the one or more electrical connectors 109 may receive data from one or more sensors (e.g., operational data, environmental data, and the like) within the mid-drive motor package 100 and / or transmit data or other instructions to components within the mid-drive motor package 100. The one or more electrical connectors 109 may be individual connectors and / or may be leads grouped into one or more plugs or receptacles that are configured to engage with corresponding components on a wire or harness coupled to the mid-drive motor package 100, without departing from the scope of the present disclosure. In some configurations, the electrical connectors 109 extend from apertures of and / or are mounted on exterior surfaces of the housing 108.

[0137] Reference will be made to the CVT 102 in detail further herein. It is noted that any and / or all of the subassemblies of the CVT 102 may include further subassemblies as described in detail further herein, which are each considered subassemblies of the mid-drive motor package 100.

[0138] Fig. IB illustrates the CVT 102 of the mid-drive motor package 100, in accordance with one or more embodiments of the present disclosure. The CVT 102 includes a generator subassembly 110 with a generator gearbox 112 and a generator motor 114. The CVT 102 also includes a traction subassembly 116 with a traction motor 118 and a traction gearbox 120.

[0139] In embodiments, the mid-drive motor package 100 is able to receive a user input and modify a user input to provide a power output. For example, the generator subassembly 110 is able to receive the user input and convert or transform the kinetic energy of the user input into electrical power. By way of another example, the traction subassembly 116 is able to receive electrical power and produce the power output for the output sprocket 106.

[0140] The crankshaft 104 and the generator subassembly 110 are disconnected (or mechanically uncoupled) from the output sprocket 106, and do not provide a direct torque to the output sprocket 106. In addition, the traction subassembly 116 is disconnected (or mechanically uncoupled) from the crankshaft 104 and the generator subassembly 110, and does not receive a user input from the crankshaft 104 or a kinetic energy input from the generator subassembly 110. Further, only the traction subassembly 116 provides the powerAttorney Docket No. 11042-14-PCT

[0141] output (or the torque) to the output sprocket 106. As described in detail further herein, however, the axial configuration or build of the crankshaft 104, the generator subassembly 110, and the traction subassembly 116 may result in bearing, seals, or the like that contact or otherwise engage surfaces of the crankshaft 104, the generator subassembly 110, and / or the traction subassembly 116 to assist in rotation of the crankshaft 104 within the axial openings through the generator subassembly 110 and / or the traction subassembly 116, without departing from the scope of the present disclosure.

[0142] In the CVT 102, the generator subassembly 110 and the traction subassembly 116 are separated by a reference plane P (e.g., as illustrated in Fig. IE). Within the generator subassembly 110, the generator motor 114 is positioned lateral relative to the reference plane P and the generator gearbox 112 is positioned medial relative to the reference plane P. Within the traction subassembly 116, the traction motor 118 is positioned lateral relative to the reference plane P and the traction gearbox 120 is positioned medial relative to the reference plane P. It is noted that “lateral” means to be positioned or distanced further from the reference plane P, and “medial” means to be positioned or distanced closer to the reference plane P, for purposes of the present disclosure.

[0143] In some embodiments, the generator gearbox 112 and the traction gearbox 120 are in separate gearbox housings that are coupled together. In other embodiments, the generator gearbox 112 and the traction gearbox 120 are in entirely separate gearbox housings. In further embodiments, the generator gearbox 112 and the traction gearbox 120 are combined within a single gearbox housing. For example, gear oil may be applied to all gear systems within the single gearbox housing for both the generator gearbox 112 and the traction gearbox 120, as opposed to gear oil being localized to each of the gearboxes 112, 120 with the separate gearbox housings.

[0144] In embodiments, the generator motor 114 and / or the traction motor 118 is an axial flux motor capable of receiving the crankshaft 104 as it passes through the CVT 102. This allows for a configuration along a single longitudinal axis through the crankshaft 104, as opposed to a multi-axis build with separate parallel (or substantially parallel) axes for the generator motor 114, the generator gearbox 112, the traction motor 118, and / or the traction gearbox 120.

[0145] It is noted that embodiments of the CVT 102 have the traction subassembly 116 positioned between the generator subassembly 110 and the output sprocket 106. It is contemplated, however, that the generator subassembly 110 may be positioned between theAttorney Docket No. 11042-14-PCT

[0146] traction subassembly 116 and the output sprocket 106, without departing from the scope of the present disclosure.

[0147] Fig. 1C illustrates a schematic flow of power through the CVT 102 within the middrive motor package 100, including through the generator subassembly 110 and the traction subassembly 116. It should be understood that Fig. 1C represents a cross-section view of the CVT 102.

[0148] In embodiments, the generator gearbox 112 of the generator subassembly 110 includes a first ring gear 122, a first set of planet gears 124 in communication with a second set of planet gears 126 via a planet carrier 128, and a second ring gear 130. It is noted that components of the generator gearbox 112 may be considered “generator” components, for purposes of the present disclosure (i.e., generator ring gears or generator ring gears, sets of generator planet gears on a generator planet carrier or sets of generator planet gears on a generator planet carrier, and the like).

[0149] The user input is received by the first ring gear 122 from the crankshaft 104. Optionally, the user input passes through a clutch 132 between the crankshaft 104 and the first ring gear 122. For example, the clutch 132 may be a one-way clutch that allows for the transfer of user input from the crankshaft 104 to the first ring gear 122 of the generator gearbox 112, but that prevents power from being transferred from the first ring gear 122 of the generator gearbox 112 to the crankshaft 104.

[0150] The user input is transferred from the first ring gear 122 to the planet carrier 128 via the first set of planet gears 124. The second ring gear 130 is fixed in place within the generator gearbox 112, such that the second set of planet gears 126 is able to rotate. The rotation of the planet carrier 128 converts and transfers kinetic energy from the crankshaft 104 to the generator motor 114 of the generator subassembly 110.

[0151] In some embodiments, the first set of planet gears 124 and the second set of planet gears 126 have a different count of teeth, effecting a conversion ratio as kinetic energy from the received user input is transferred to the generator motor 114 by the generator gearbox 112. For example, the conversion ratio may be 1:19, 1 :40, 1 :49, or other ratio that converts the kinetic energy from the user input to usable kinetic energy for generation of electrical power with the generator motor 114. In other words, the ratio is such that speed is increased and torque is decreased to make the power usable for generation of electrical power. In some non-limiting examples, the ratio based on the second ring gear 130 may be dependent at least in part on the user input received from the crankshaft 104 via the first ring gear 122,Attorney Docket No. 11042-14-PCT

[0152] the first ring gear 122 being driven by the crankshaft 104 as described in detail further herein.

[0153] It is noted that the generator gearbox 112 may be understood as being capable of kinetic energy conversion from a low speed / high torque user input to a high speed / low torque output to facilitate electrical power generation with the generator motor 114, for purposes of the present disclosure. Further still, the generator gearbox 112 can be described as receiving mechanical power at a first torque and then outputting the mechanical power at a second torque that is less than the first torque.

[0154] In embodiments, the traction gearbox 120 of the traction subassembly 116 includes a first ring gear 134, a first set of planet gears 136 in communication with a second set of planet gears 138 via a planet carrier 140, and a second ring gear 142. It is noted that components of the traction gearbox 120 may be considered “traction” components, for purposes of the present disclosure (i.e., traction ring gears, sets of traction planet gears on a traction planet carrier, and the like).

[0155] The traction motor 118 of the traction subassembly 116 receives an electrical power input, which is transferred to the planet carrier 140. The first ring gear 134 is fixed in place within the traction gearbox 120, such that the first set of planet gears 136 is able to rotate. The second ring gear 142 is able to rotate when acted upon by the planet carrier 140 via the second set of planet gears 138. The rotation of the second ring gear 142 produces the output power (e.g., a torque) via an output shaft 144 for the output sprocket 106 (not shown).

[0156] In some embodiments, the first set of planet gears 136 and the second set of planet gears 138 have a different count of teeth, effecting a power conversion ratio as the output power (e.g., a torque) is produced by the traction gearbox 120. For example, the ratio may be 19:1, 40:1, 49:1, or other ratio that converts traction motor input into power output for the output sprocket 106 via the traction gearbox 120. In other words, the ratio is such that speed is decreased and torque is increased to make the power more usable for driving the output sprocket 106.

[0157] In this regard, power from the crankshaft 104 is provided to the output sprocket 106 via the generator subassembly 110 and then the traction subassembly 116. User input from the crankshaft 104 is first converted to electrical power, with the user input being converted by the generator gearbox 112 which drives the generator motor 114 to produce the electrical power. Electrical power is also provided to the traction motor 118, which acts upon the traction gearbox 120 to produce the output power (e.g., a torque) for the output sprocketAttorney Docket No. 11042-14-PCT

[0158] 106, thus providing power to a hub of a wheel (e.g., via a belt or chain connecting the output sprocket 106 to the hub, although not shown). Further still, the traction gearbox 120 can be described as receiving mechanical power at a first torque and then outputting the mechanical power at a second torque that is greater than the first torque.

[0159] In embodiments, the mid-drive motor package 100 includes (and / or is in communication with) a controller 146. In one non-limiting example, the controller 146 is housed within (or otherwise a component of) the mid-drive motor package 100, with the controller 146 being in communication with another main controller for the electric bicycle via one or more harnesses. In another non-limiting example, the controller 146 may be the main controller for the electric bicycle. For instance, the main controller for the electric bicycle may be the controller 146 of the mid-drive motor package 100, such that other components of the electric bicycle are in communication with the mid-drive motor package 100 via one or more harnesses. In addition, the main controller for the electric bicycle may be housed outside of the mid-drive motor package 100, such that the mid-drive motor package 100 and other components of the electric bicycle are in communication with the main controller via one or more harnesses.

[0160] In embodiments, electrical power from the generator motor 114 is provided to the controller 146. The controller 146 may directly or indirectly supply the electrical power to a battery installed on the electric bicycle. Alternatively or in addition, the controller 146 may provide the electrical power to the traction motor 118. In other words, the battery receives electrical power from the generator motor 114 and stores the electrical energy. Then, from this stored electrical energy, the battery produces electrical power for the traction motor 118. The charging and discharging of the battery are regulated by one or more controllers 146, in some embodiments. In general, it should be understood that the electrical power from the generator motor 114 may be supplied directly to the traction motor 118 either with or without the intervening or intermediary controller 146, and / or with or without first being supplied to a battery, without departing from the scope of the present disclosure.

[0161] Figs. ID and IE illustrate cross-section views of the CVT 102 and the crankshaft 104 of the mid-drive motor package 100.

[0162] In the CVT 102, user input through the optional clutch 132 rotates the first ring gear 122 of the generator gearbox 112. The planet carrier 128 of the generator gearbox 112 includes a shaft 148 with a first end to which the generator motor 114 engages, and a second end with (or coupled to) a flange 150. The flange 150 of the planet carrier 128 includes oneAttorney Docket No. 11042-14-PCT

[0163] or more axles 152 to which the first set of planet gears 124 and the second set of planet gears 126 of the generator gearbox 112 are coupled. As the second ring gear 130 is fixed, rotation of the first set of planet gears 124 causes the planet carrier 128 to rotate, which in turn causes the flange 150 (and thus the shaft 148) to rotate. Rotation of the shaft 148 causes the generator motor 114 to produce electrical power.

[0164] In addition, electrical power is supplied to the traction motor 118. The planet carrier 140 of the traction gearbox 120 includes a shaft 154 with a first end to which the traction motor 118 engages, and a second end with (or coupled to) a flange 156. The flange 156 of the planet carrier 140 includes one or more axles 158 to which the first set of planet gears 136 and the second set of planet gears 138 of the traction gearbox 120 are coupled. As the first ring gear 134 is fixed, rotation of the planet carrier 140 causes the second set of planet gears 138 to rotate, which in turn causes the second ring gear 142 to rotate.

[0165] The output shaft 144 is coupled to the second ring gear 142, and rotation of the second ring gear 142 causes the output shaft 144 to rotate, providing output power (e.g., a torque) to the output sprocket 106 (not shown).

[0166] In embodiments, the output shaft 144 includes splines 162 for the output sprocket 106 (not shown). In one non-limiting example, the splines 162 are on an exterior surface of the output shaft 144 (e.g., as illustrated in Fig. IB), such that the output sprocket 106 slides over and engages with the output shaft 144 via the splines 162. In another non-limiting example, the splines 162 are on an interior surface of the output shaft 144 (e.g., as illustrated in Fig. ID), such that a portion of the output sprocket 106 is inserted into and engages with the output shaft 144 via the splines 162. It is noted, however, that the output sprocket 106 may be press-fit onto (or into) the output shaft 144.

[0167] It is noted that one or more bearings may be positioned along the longitudinal axis through the crankshaft 104 to improve the rotation of the components of the generator gearbox 112 and / or the traction gearbox 120. In addition, it is noted that one or more seals (e.g., O-rings, gaskets, rope seals, or the like) may be positioned along the longitudinal axis through the crankshaft 104. For example, the seals may be utilized to prevent gear oil from escaping the CVT 102. By way of another example, the seals may be utilized to prevent fluid or particulates from entering the CVT 102.

[0168] As illustrated in Fig. IE, the CVT 102 includes a generator pathway 164, an electrical pathway 166, and a traction pathway 168.Attorney Docket No. 11042-14-PCT

[0169] In the generator pathway 164, user input is provided via a crankshaft 104 to the generator gearbox 112. The user input is transferred through the generator gearbox 112 via the first ring gear 122, the first set of planet gears 124, and the planet carrier 128. Transfer of the user input through the generator gearbox 112 converts the user input into usable kinetic energy for the generator motor 114, which is provided to the generator motor 114 via the axle 152, the flange 150, and the shaft 148. Electrical power is then provided by the generator motor 114 to the electrical pathway 166.

[0170] In the traction pathway 168, electrical power is received by the traction motor 118 from the electrical pathway 166. The traction motor 118 turns the shaft 154, which causes the flange 156 and the planet carrier 140 of the traction gearbox 120 to rotate. The planet carrier 140 rotates the second set of planet gears 138, which causes the second ring gear 142 to rotate. Rotation of the second ring gear 142 causes the output shaft 144 to rotate, providing output power (e.g., a torque) to the output sprocket 106 (not shown) coupled to the splines 162.

[0171] In embodiments, the output shaft 144 of the traction gearbox 120 is disconnected 169 from the housing of the generator gearbox 112, such that the traction gearbox 120 and the generator gearbox 112 are independent mechanical operators. Instead, the electrical pathway 166 between the generator motor 114 and the traction motor 118 causes the traction motor 118 (and when included, the traction gearbox 120) to operate. As previously noted herein, the electrical pathway 166 may include one or more intervening or intermediary components between the generator motor 114 and the traction motor 118 including, but not limited to, a controller 146, a secondary or main controller, a battery, or the like. However, it should be understood that the electrical pathway 166 may be a direct pathway between the generator motor 114 and the traction motor 118. In addition, it should be understood that the electrical pathway 166 may be supplemental from additional electrical sources in addition to the generator motor 114, such as a battery.

[0172] In this regard, the user input from the crankshaft 104 is modified into output power (e.g., a torque) to the output sprocket 106 via the generator subassembly 110 and the traction subassembly 116. The generator subassembly 110 and the traction subassembly 116 provides a CVT transmission build for the mid-drive motor package 100, and reduces the possibility of dead zones or dead battery mode. Notably, where the electrical pathway 166 is a direct pathway between the generator subassembly 110 and the traction subassemblyAttorney Docket No. 11042-14-PCT

[0173] 116 (with optional controller 146 therebetween), the conversion of user input to modified power output can still occur even with a dead battery.

[0174] In addition, the generator subassembly 110 and the traction subassembly 116 provides the option for a reverse mode of operation, in addition to the standard forward mode of operation. In general, the configuration or build of the generator subassembly 110 and the traction subassembly 116 results in fewer components and reduced weight of the mid-drive motor package 100 as compared to other known solutions, which reduces manufacturing costs and increases ease or operation and use of the electric bicycle for a user.

[0175] Although it is contemplated there may be losses in efficiency with the gears and motors as arranged in the generator subassembly 110 and the traction subassembly 116, it is noted that any losses may be supplemented by a battery in communication with (or a part of) the electrical pathway 166.

[0176] Fig. 2 is a flow diagram of a method or process 200 illustrating the operation of the mid-drive motor package 100, in accordance with one or more embodiments of the present disclosure. While a general order for the steps of the method or process 200 is shown in Fig.

[0177] 2, the method or process 200 can include more or fewer steps or can arrange the order of the steps differently (including simultaneously, substantially simultaneously, or sequentially) than those shown in Fig. 2. It is noted that the method or process 200 shall be explained with reference to the components, devices, subassemblies, environments, etc. described in conjunction with Figs. 1 A-1E. For example, it is noted that the embodiments as illustrated in Figs. 1 A-1E should be understood as reading on the embodiments described with respect to Fig. 2, and vice versa, without departing from the scope of the present disclosure.

[0178] In embodiments, user input is received 202 from a crankshaft with a generator subassembly of the mid-drive motor package. The user input from the crankshaft 104 is transferred to the generator gearbox 112 of the generator subassembly 110.

[0179] In embodiments, the user input is converted 204 to electrical power in the generator subassembly of the mid-drive motor package. The received user input is modified with the generator gearbox 112 into input kinetic energy usable by a generator motor 114 of the generator subassembly 110. The generator motor 114 produces electrical power from the input kinetic energy, and outputs the electrical power. For example, the electrical power may be output to a controller. By way of another example, the electrical power may be output to a battery pack. By way of another example, the electrical power may be output toAttorney Docket No. 11042-14-PCT

[0180] the traction subassembly 116. Further, the electrical power may be output to a combination of any of the above.

[0181] In embodiments, electrical power is received 206 by a traction subassembly of the mid-drive motor package. The electrical power may be received by a traction motor 118 of the traction subassembly 116. For example, the electrical power may be received from a controller. By way of another example, the electrical power may be received from a battery pack. By way of another example, the electrical power may be received from the traction subassembly 116. Further, the electrical power may be received from a combination of any of the above.

[0182] In embodiments, electrical power is converted 208 to output power (e.g., a torque) for an output sprocket of the mid-drive motor package. The received electrical power is used by the traction motor 118 to produce output kinetic energy (e.g., in the form of rotational energy). The produced output kinetic energy acts on the traction gearbox 120, which produces output power (e.g., a torque) from the output kinetic energy for the output sprocket 106.

[0183] In this regard, by properly controlling the generator subassembly 110 and the traction subassembly 116, the CVT 102 achieves variable transmission functionality while reducing or eliminating possible dead zones (e.g., at or near zero RPM).

[0184] Fig. 3 illustrates a schematic of an electric bicycle, in accordance with one or more embodiments of the present disclosure. In particular, Fig. 3 illustrates an electric bicycle 300 with the mid-drive motor package 100, as described throughout the present disclosure. It should be understood that assemblies, subassemblies, and / or components of the electric bicycle 300 may be similar or identical to assemblies, subassemblies, and / or components of the mid-drive motor package 100, unless otherwise noted.

[0185] Referring now to Fig. 3, the electric bicycle 300 includes the mid-drive motor package 100 with the CVT 102 including the generator subassembly 110 and the traction subassembly 116, the crankshaft 104, and the output sprocket 106. The electric bicycle 300 has a belt or chain 302 that couples to the output sprocket 106 of the mid-drive motor package 100. The belt or chain 302 is coupled to a hub 304 of a wheel 306, such rotation of the output sprocket 106 causes actuation of the belt or chain 304 and subsequent rotation of the hub 304 and the wheel 306.

[0186] User input 305 from the crankshaft 104 is converted by the generator subassembly 110 into electrical power 307. The electrical power 307 is provided to the tractionAttorney Docket No. 11042-14-PCT

[0187] subassembly 116. For example, the electric bicycle 300 includes a battery pack 308, which provides electrical power 307 to the traction subassembly 116. By way of another example, the electrical power 307 is provided to the traction subassembly 116 directly from the generator subassembly 110.

[0188] The electric bicycle 300 includes a control system 310 that controls power input to and / or power output from the battery pack 308, user input to and / or electrical power output from the generator subassembly 110, and / or electrical power input to and / or output power 309 (e.g., a torque) from the traction subassembly 116. The control system 310 may be coupled to the battery pack 308 and / or the mid-drive motor package 100 via wired connections and / or via wireless connections. In some embodiments, the control system 310 includes the controller 146, and the electrical power from the generator subassembly 110 and / or the battery pack 308 may be routed through the controller 146.

[0189] Select embodiments of the mid-drive motor package 100 are directed to two motors with no mechanical connection to one another. User input from the crankshaft 104 drives the generator motor 114 to produce electrical power to charge a battery pack (e.g., either directly, or via the controller 146). Electrical power is then delivered to the traction motor 118, which is connected to the output sprocket 106 and drives a hub (and rear wheel).

[0190] Because only electrical power is provided to the traction subassembly 116 to produce the output power (e.g., a torque), such that the crankshaft 104 is decoupled from the output sprocket 106, embodiments of the present disclosure are also directed to a reverse gear. For example, electrical power may be provided to the traction motor 118 to cause the traction motor 118 to operate in a first direction (e.g., clockwise or counterclockwise) to propel the electric bicycle 300 forward using a forward gear, while electrical power may be provided to the traction motor 118 to cause the traction motor 118 to operate in a second direction (e.g., the other of clockwise or counterclockwise) to propel the electric bicycle 300 backward using a reverse gear. As such, the electric bicycle 300 may include user controls to select a magnitude of speed (e.g., via predetermined incremental settings, via a rotatable throttle or lever on the handlebars, via proportional electrical power adjustment based on user input, and the like). In addition, the electric bicycle 300 may include user controls to select a direction of speed (e.g., forwards or backward) with the control system 310. It is noted that whether the electric bicycle 300 is propelled forwards or backwards is independent of the user providing a user input via the crankshaft 104.Attorney Docket No. 11042-14-PCT

[0191] It is noted that embodiments of the present disclosure are directed to a mid-drive motor package 100 with a generator subassembly 110 with the generator gearbox 112 and the generator motor 114, and the traction subassembly 116 with the traction gearbox 120 and the traction gearbox 120. However, it should be understood that the mid-drive motor package 100 may include only a generator motor 114 that directly receives user input from the crankshaft 104, and a traction motor 118 that directly provides output power (e.g., a torque) to the output sprocket 106, without departing from the scope of the present disclosure. In this regard, the generator gearbox 112 and / or the traction gearbox 120 may be considered optional components in certain configurations or build of the mid-drive motor package 100.

[0192] In some embodiments, the traction motor 118 is controlled by the control system 310, which receives inputs directed to a target pedal cadence and a measured pedal cadence. The inputs are fed into a controller (e.g., a proportional or “P” controller, an integral or “I” controller, a derivative or “D” controller, or some combination thereof including, but not limited to, a PID controller), which outputs one or more commands to the traction motor 118 for speed and / or direction of rotation. The traction motor 118 is thus speed-controlled by the control system 310, which compares ride cadence to target cadence and produces the commands for the traction motor 118. For example, if a user pedals faster than the target cadence, the electric bicycle 300 will speed up. By way of another example, if the user pedals slower than the target cadence, the electric bicycle 300 will slow down. It is noted that the target cadence can be substantially constant and independent of bicycle speed, or may be dependent on the bicycle speed.

[0193] In some embodiments, the generator motor 114 is controlled by the control system 310, which receives inputs directed to a measured traction motor power and a generated speed, the combination of which is combined with a rider profile (e.g., that is selected via a user interface or other human-machine interface) to produce a torque command for the generator motor 114. For example, traction motor power may be divided by the generator speed, and the output may be multiplied by one or more parameters from the selected rider profile, to determine the torque command for the generator motor 114. This determination thus provides feedback to a user based on an effort applied by the user to move the electric bicycle 300. The rider profile may be pre-defined, based on general parameters believed to be desirable by the user, or may be custom-built. For example, the pre-defined rider profiles may be based on a level of resistance that the user has to overcome with applied effort. ForAttorney Docket No. 11042-14-PCT

[0194] instance, the pre-defined rider profiles may change the multiplier applied in the above determination for the torque command. It is noted that a higher effort applied by the user will result in a longer battery life, as more energy will be generated by the user. It is contemplated that a non-battery application of power may set the multiplier gain to a fixed value.

[0195] In one example of operation, a user wants to speed up on a flat road. To accomplish this, the user pedals faster than the target cadence, which causes the speed of the electric bicycle 300 to increase based on an increased speed command to the traction motor 118. The torque command to the generator motor 114 also increases based on the increased traction motor power, and the user cadence then slows down from increased load. This is repeated until the target cadence is reached at a new operating point of higher speed for the electric bicycle 300.

[0196] In another example of operation, a user wants to slow down on a flat road. To accomplish this, the user pedals slower than the target cadence, which causes the speed of the electric bicycle 300 to decrease based on a decreased speed command to the traction motor 118. The torque command to the generator motor 114 also decreases based on the decreased traction motor power, and the user cadence then increases from decreased load. This is repeated until the target cadence is reached at a new operating point of lower speed for the electric bicycle 300.

[0197] In a further example of operation, a user wants to ride uphill. To accomplish this, the torque for the traction motor 118 and the torque for the generator motor 114 both increase due to the uphill slope. The user pedals slower than the target cadence from the increased load, and the speed of the electric bicycle 300 decreases. It is noted, however, that the speed of the electric bicycle 300 may remain substantially constant with additional applied user effort to maintain cadence.

[0198] In a further example of operation, a user wants to ride downhill. To accomplish this, the torque for the traction motor 118 and the torque for the generator motor 114 both decrease due to the downhill slope. If the user applies additional effort to increase cadence from the decreased load, the electric bicycle 300 will speed up. Alternatively, if the user applies less effort to maintain cadence, the speed of the electric bicycle 300 will remain substantially constant. Alternatively still, if the user applies zero effort (i.e., stops pedaling), the traction motor 118 and / or the generator motor 114 may shut off and the user may coast on the electric bicycle 300.Attorney Docket No. 11042-14-PCT

[0199] In general, the control system 310 may include one or more control units (e.g., a controller, server, or the like). The one or more control units may include processors and memory (e.g., a memory medium, memory device, or the like). The processors may be configured to execute program instructions maintained on or stored in the memory. The processor of the one or more control units may execute any of the various method or process steps necessary to operate the electric bicycle 300, and / or the subassemblies and / or components of the electric bicycle 300.

[0200] The control system 310 may include a user interface coupled (e.g., physically coupled, electrically coupled, communicatively coupled, or the like) to the one or more control units. For example, the user interface may be a separate device coupled to the one or more control units. By way of another example, the user interface and the one or more control units may be located within a common or shared housing. The user interface may include one or more displays, one or more user input devices, and / or one or more port connectors (e.g., for the transmitting and / or receiving of power and / or data, and the like).

[0201] The control system 310 may include one or more sensors coupled (e.g., physically coupled, electrically coupled, communicatively coupled, or the like) to or integrated in the one or more control units, the electric bicycle 300, and / or the subassemblies and / or components of the electric bicycle 300. The one or more sensors may be operable to determine various operational, physical, and / or environmental parameters of the electric bicycle 300, the subassemblies and / or components of the electric bicycle 300, and / or the control system 310; the environment surrounding the electric bicycle 300, the subassemblies and / or components of the electric bicycle 300, and / or the control system 310, and the like. For instance, the sensors may be operable to determine the power input and / or power output of the electric bicycle 300, the subassemblies and / or components of the electric bicycle 300, and / or the control system 310.

[0202] The control system 310 may include one or more transmitters and / or receivers coupled (e.g., physically coupled, electrically coupled, communicatively coupled, or the like) to or integrated in the one or more control units, the electric bicycle 300, and / or the subassemblies and / or components of the electric bicycle 300. The one or more transmitters and / or receivers may be configured to transmit data 311 and / or receive data 311 for the electric bicycle 300 and / or the subassemblies and / or components of the electric bicycle 300 (e.g., from sensors installed within the electric bicycle 300 and / or the subassemblies and / or components of the electric bicycle 300) or from external third-party control units (e.g.,Attorney Docket No. 11042-14-PCT

[0203] controllers, servers, or the like) either via wired connections or wireless connections, which may be configured as transmitting (Tx) units, receiving (Rx) units, or combination Tx / Rx units.

[0204] The control system 310 may be configured to monitor the electric bicycle 300 and / or the subassemblies and / or components of the electric bicycle 300 via received and / or transmitted data. The control system 310 may be configured to generate control signals to adjust one or more components of the electric bicycle 300 and / or the subassemblies and / or components of the electric bicycle 300 via a feedback loop or a feed forward loop based on the received and / or transmitted data, either automatically or following an input from a user. The control system 310 may be configured to receive and / or transmit data in a standardized format and / or a non-standardized format. Where the data is in a non-standardized format, the data may be converted to a standardized format upon receipt and / or prior to transmission to sensors, third-party control units, or the like.

[0205] In this regard, advantages of the present disclosure include a compact-size CVT in a mid-drive motor package for an electric bicycle. Advantages of the present disclosure are directed to planetary gear systems in the CVT. Advantages of the present disclosure are also directed to axial flux motors in the CVT. Advantages of the present disclosure include gear systems and motors that are each coaxial along a longitudinal axis through a crankshaft insertable through the planetary gear system and motors. Advantages of the present disclosure are directed to a CVT that reduces or eliminates dead zones while maintaining CVT functionality.

[0206] To this effect, advantages of the present disclosure are directed to a CVT that includes a generator subassembly able to receive a user input via a crankshaft, and a traction subassembly able to provide output power (e.g., a torque) for an output sprocket, where the generator subassembly converts kinetic energy from the user input into electrical power that is usable by the traction subassembly to produce the output power (e.g., a torque). Advantages of the present disclosure are directed to a controller that monitors and regulates the electrical power output from the generator subassembly and to the traction subassembly, including with power storage into and / or power providing out of a battery or battery pack. Advantages of the present disclosure include providing output power (e.g., a torque) that is modified user input power which is optionally supplemented with assist power (e.g., from the battery or battery pack).Attorney Docket No. 11042-14-PCT

[0207] Although embodiments of the present disclosure are directed to the use of the described mid-drive motor packages with an electric bicycle, it should be understood that this should not be interpreted as limiting on the present disclosure. For example, the middrive motor packages (and / or components thereof) may be installed on other wheeled devices including, but not limited to, scooters, wheelchairs, unicycles, tricycles, small rover vehicles, all terrain vehicles, utility terrain vehicles, motorcycles, automobiles, recreation vehicles, construction vehicles, warehouse and freight transportation vehicles, lawn and farm implement machinery, or any wheeled device that may benefit from the application of power (e.g., through a CVT) to assist in propulsion of the wheeled device.

[0208] While various embodiments of the present disclosure have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be understood that such modifications and alterations are within the scope and spirit of the present disclosure, as set forth in the following claims. Further, the invention(s) described herein is capable of other embodiments and of being practiced or of being carried out in various ways. It is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

Claims

Attorney Docket No. 11042-14-PCTCLAIMSWhat is claimed is:

1. A continuously variable transmission of a mid-drive motor package, comprising:a generator subassembly comprising a generator motor, wherein the generator motor is configured to receive a mechanical power input from a crankshaft of the mid-drive motor package and is configured to produce an electrical power output; anda traction subassembly comprising a traction motor, wherein the traction motor is configured to receive an electrical power input and is configured to produce a mechanical power output to drive an output sprocket of the mid-drive motor package,wherein the generator subassembly and the crankshaft are mechanically uncoupled from the output sprocket, and wherein the traction subassembly is mechanically uncoupled from the crankshaft.

2. The continuously variable transmission of claim 1, wherein a battery pack is configured to receive the electrical power output from the generator motor and is configured to store electrical energy, and wherein the battery pack is configured to produce the electrical power input to the traction motor.

3. The continuously variable transmission of claim 2, wherein a controller is configured to regulate a charging process of the battery pack where the electrical power output is stored as electrical energy, and the controller is configured to regulate a discharging process where the electrical energy is released as the electrical power input to the traction motor.

4. The continuously variable transmission of claim 1, wherein the electrical power input received by the traction motor causes the traction motor to rotate in a forward direction.

5. The continuously variable transmission of claim 1, wherein the electrical power input received by the traction motor causes the traction motor to rotate in a reverse direction.

6. The continuously variable transmission of claim 1, wherein the generator subassembly includes a generator gearbox that is configured to receive the mechanical power input at a first torque and is configured to transmit the mechanical power input at a second torque to the generator motor, and wherein the second torque is less than the first torque.Attorney Docket No. 11042-14-PCT7. The continuously variable transmission of claim 6, wherein the generator gearbox comprises:a first ring gear that is configured to receive the mechanical power input at the first torque;a second ring gear that is fixed;a first set of planet gears that engage the first ring gear;a second set of planet gears that engage the second ring gear; anda planet carrier to which the first set of planet gears and the second set of planet gears are coupled, wherein rotation of the first ring gear is configured to cause the planet carrier to transmit the mechanical power input at the second torque for the generator motor.

8. The continuously variable transmission of claim 1, wherein the traction subassembly includes a traction gearbox that is configured to receive the mechanical power output at a first torque from the traction motor and is configured to transmit the mechanical power output at a second torque to the output sprocket, wherein the second torque is greater than the first torque.

9. The continuously variable transmission of claim 8, wherein the traction gearbox comprises:a first ring gear that is fixed;a second ring gear that is configured to transmit mechanical power to the output sprocket;a first set of planet gears that engage the first ring gear;a second set of planet gears that engage the second ring gear; anda planet carrier to which the first set of planet gears and the second set of planet gears are coupled, wherein rotation of the planet carrier with the mechanical power output at the first torque causes the second ring gear to transmit the mechanical power output at the second torque to the output sprocket.

10. A mid-drive motor package, comprising:a crankshaft able to receive a user input from a user;an output sprocket able to output an output torque; anda continuously variable transmission, comprising:a generator subassembly comprising a generator motor, wherein the generator motor receives the user input from the crankshaft and outputs a first amount of electrical power; andAttorney Docket No. 11042-14-PCTa traction subassembly comprising a traction motor, wherein the traction motor receives a second amount of electrical power and produces the output torque for the output sprocket,wherein the generator subassembly and the crankshaft are mechanically uncoupled from the output sprocket, and wherein the traction subassembly is mechanically uncoupled from the crankshaft.

11. The mid-drive motor package of claim 10, wherein the generator subassembly includes a generator gearbox that receives the user input from the crankshaft and converts input kinetic energy from the user input into an input torque for the generator motor, and wherein the generator motor uses the input torque to generate the first amount of electrical power.

12. The mid-drive motor package of claim 11, wherein the generator gearbox comprises:a first ring gear that receives the user input from the crankshaft;a second ring gear that is fixed;a first set of planet gears that engage the first ring gear;a second set of planet gears that engage the second ring gear; anda planet carrier to which the first set of planet gears and the second set of planet gears are coupled, wherein rotation of the planet carrier converts the input kinetic energy from the user input into the input torque for the generator motor.

13. The mid-drive motor package of claim 10, wherein the traction motor uses the second amount of electrical power to generate output kinetic energy, and wherein the traction subassembly includes a traction gearbox that uses the output kinetic energy to generate the output torque for the output sprocket.

14. The mid-drive motor package of claim 13, wherein the traction gearbox comprises:a first ring gear that is fixed;a second ring gear that provides the output torque to the output sprocket;a first set of planet gears that engage the first ring gear;a second set of planet gears that engage the second ring gear; anda planet carrier to which the first set of planet gears and the second set of planet gears are coupled, wherein the output kinetic energy from the traction motor rotates the planet carrier to rotate and the second ring gear to produce the output torque for the output sprocket.Attorney Docket No. 11042-14-PCT15. An electric bicycle, comprising:a mid-drive motor package, the mid-drive motor package comprising:a crankshaft able to receive a user input from a user;an output sprocket able to output an output torque; anda continuously variable transmission configured to receive the user input from the crankshaft and configured to produce the output torque for the output sprocket, wherein the crankshaft is mechanically uncoupled from the output sprocket.

16. The electric bicycle of claim 15, wherein the continuously variable transmission comprises:a generator subassembly comprising a generator motor, wherein the generator motor receives the user input from the crankshaft and outputs a first amount of electrical power; anda traction subassembly comprising a traction motor, wherein the traction motor receives a second amount of electrical power and produces the output torque for the output sprocket, wherein the generator subassembly is mechanically uncoupled from the output sprocket, and the traction subassembly is mechanically uncoupled from the crankshaft.

17. The electric bicycle of claim 16, further comprising:a battery pack, wherein the first amount of electrical power outputted by the generator motor is outputted to the battery pack of the electric bicycle, and wherein the second amount of electrical power received by the traction motor is received from the battery pack.

18. The electric bicycle of claim 16, further comprising:a controller, wherein the first amount of electrical power outputted by the generator motor is determined by the controller, and wherein the second amount of electrical power received by the traction motor is determined by the controller.

19. The electric bicycle of claim 16, wherein the second amount of electrical power received by the traction motor is configured to propel the electric bicycle in a forward direction.

20. The electric bicycle of claim 16, wherein the second amount of electrical power received by the traction motor is configured to propel the electric bicycle in a reverse direction.

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