Drive systems for human-powered vehicles

Abstract

A drive system for a human-powered vehicle, comprising a transmission system having a plurality of different selectable gear ratios and including one or more clutches for shifting from one of the gear ratios to another, and a controller configured to receive a shift command and, in response to receiving the shift command, when a torque and / or a speed of the crank axle is below a predetermined threshold, to power the electric motor and control the one or more clutches to shift from one of the gear ratios to the other.

Description

AREA

[0001] The invention relates to a drive system for muscle-powered vehicles, such as bicycles. GENERAL STATE OF THE ART

[0002] Drive systems for human-powered vehicles, such as bicycles, are known. Such drive systems are known to include a gear system having a plurality of different selectable gear ratios. Such a drive system may include, for example, a chainring mounted on a crank axle for driving one of a plurality of sprockets mounted on a wheel axle via a chain to provide a plurality of different selectable gear ratios. A drive system may include an internally toothed hub assembly driven, for example, via a chain or belt and providing a plurality of different selectable gear ratios. A drive system may include a crank assembly providing a plurality of different selectable gear ratios, for example, for driving a chain or belt.

[0003] When shifting from one gear ratio to another, such shifting is preferably performed smoothly. It is known that some drive systems sometimes experience difficulty shifting from one gear ratio to another under certain circumstances. For example, some drive systems exhibit difficulty shifting under load, while others may exhibit difficulty shifting at low speeds. SUMMARY

[0004] According to one aspect, a drive system for a human-powered vehicle is provided, comprising a crank axle forming an input of the drive system for receiving human drive force, and a hub shell forming an output of the drive system. The drive system includes a gear system between the input and the output, the gear system having a plurality of different selectable gear ratios and one or more clutches for switching from one of the gear ratios to another. The gear system may include one or more gear axles. The drive system includes an electric motor connected to the drive system.The drive system includes a controller configured to receive a shift command requesting a shift from one of the gear ratios to another, receive a signal representative of a torque and / or a speed of the crankshaft, in response to receiving the shift command, when a torque and / or a speed of the crankshaft is below a predetermined threshold, supply power to the electric motor, and control the one or more clutches to shift from one of the gear ratios to the other.

[0005] More specifically, a drive system for a human-powered vehicle is provided, comprising a crank axle forming an input of the drive system for receiving human drive force, and a front sprocket forming an output of the drive system, or a rear sprocket forming an input of the drive system for receiving human drive force. The drive system includes a gear system between the input and the output, the gear system having a plurality of different selectable gear ratios and one or more clutches for switching from one of the gear ratios to another. The gear system has an input connectable to the input of the drive system. The gear system has an output connectable to the output of the drive system. The gear system may include one or more gear axles.The drive system includes an electric motor connected to the drive system. The electric motor may be configured to drive, e.g., assist in driving, a portion of the drive system. The drive system includes a controller configured to receive a shift command requesting a shift from one of the gear ratios to another. The controller is configured to receive a signal representative of a torque and / or a speed of the crankshaft and / or the rear sprocket. The controller is configured, in response to receiving the shift command, when a torque and / or a speed of the crankshaft and / or the rear sprocket is below a predetermined threshold, to power the electric motor and control the one or more clutches to shift from one of the gear ratios to the other.For example, if the crank axle forms the input of the drive system, the controller may be configured, in response to receiving the shift command, when a torque and / or a speed of the crank axle is below a predetermined threshold, to power the electric motor and control the one or more clutches to shift from one of the gear ratios to the other. For example, if the rear sprocket forms the input of the drive system, the controller may be configured, in response to receiving the shift command, when a torque and / or a speed of the rear sprocket is below a predetermined threshold, to power the electric motor and control the one or more clutches to shift from one of the gear ratios to the other.The electric motor may drive the input of the transmission system and / or the output of the transmission system to provide sufficient rotation of the input of the transmission system relative to the output of the transmission system to efficiently shift from one of the gear ratios to another.

[0006] In the drive system, for efficient shifting, the drive system may require the input of the transmission system to rotate relative to the output of the transmission system. In view of this, for efficient shifting from one of the gear ratios to another, the transmission system including one or more clutches for shifting from one of the gear ratios to another may benefit from having a torque and / or speed of the input of the transmission system, or e.g., the crankshaft or the rear sprocket, higher than the predetermined threshold. Therefore, supplying power to the electric motor by the controller in response to receiving the shift command when a torque and / or speed of the crankshaft and / or the rear sprocket is below a predetermined threshold may contribute to efficient shifting.The electric motor may drive the input of the transmission system and / or the output of the transmission system to provide sufficient rotation of the input of the transmission system relative to the output of the transmission system to efficiently shift from one of the gear ratios to another.

[0007] If the signal representative of a torque and / or speed of the crank axle and / or rear sprocket is below the predetermined threshold, this may be representative of a coasting or near-coasting situation, or a stationary or near-stationary situation in which a rider is not rotating the crank axle or is at least rotating the crank axle with a torque and / or speed below the predetermined threshold. Rotating the crank axle with a torque and / or speed below the predetermined threshold may cause difficulties in shifting from one gear ratio to another, which may be mitigated by supplying power to the electric motor as described herein.

[0008] The signal representative of a torque and / or a rotational speed of the crank axle and / or the rear sprocket can be obtained at different locations in the vehicle. The signal representative of a torque and / or a rotational speed of the crank axle and / or the rear sprocket can be obtained, for example, by determining a signal representative of a torque and / or a rotational speed of one or more of the following: a crank arm, the crank axle, a transmission axle, a front sprocket, a rear sprocket, a chain, a drive belt, a cardan shaft, or the like. With regard to standstill or near standstill, the signal representative of a torque and / or a rotational speed of the crank axle and / or the rear sprocket can, for example,by determining a signal representative of a torque and / or a speed of a wheel or a vehicle speed.

[0009] According to one aspect, a drive system for a human-powered vehicle is provided. The drive system includes a crank axle forming an input of the drive system for receiving human drive force. The drive system includes a front sprocket forming an output of the drive system. The front sprocket may be arranged to receive a chain. Such a front sprocket is sometimes referred to as a chainring. The front sprocket may be arranged to receive a belt. Such a front sprocket is sometimes referred to as a pulley. The front sprocket may be arranged to drive a shaft drive. The drive system further includes a gear system between the input and the output. The gear system has an input that may be connectable to the input of the drive system.The transmission system has an output that can be connected to the output of the drive system. The transmission system has a plurality of different selectable gear ratios. The transmission may include one or more transmission axles. The transmission system includes one or more clutches for shifting from one of the gear ratios to another. The drive system includes an electric motor connected to the transmission system. The drive system further includes a controller. The controller is configured to receive a shift command requesting a shift from one of the gear ratios to another. The shift command may be received, for example, wired or wirelessly by a receiver of the controller. The shift command may be transmitted to the controller by a shifting device. The shifting device may include, for example, one or more shift buttons or shift levers.The controller is configured to receive a signal representative of a torque and / or a rotational speed of the crankshaft. For this purpose, the drive system may include a torque sensor and / or a crankshaft rotational speed sensor. The controller is configured, in response to receiving the shift command, when a torque and / or a rotational speed of the crankshaft is below a predetermined threshold, to supply power to the electric motor and control the one or more clutches to shift from one of the gear ratios to the other.The electric motor may drive the input of the transmission system and / or the output of the transmission system to provide sufficient rotation of the input of the transmission system relative to the output of the transmission system to efficiently shift from one of the gear ratios to another.

[0010] It is understood that the electric motor may be powered for a predetermined period of time before the one or more clutches are controlled to shift from one of the gear ratios to the other. Alternatively, it is possible for the electric motor to be powered for a predetermined period of time after the one or more clutches have been controlled to shift from one of the gear ratios to the other. It is also possible for the electric motor to be powered simultaneously with the one or more clutches being controlled to shift from one of the gear ratios to the other.

[0011] The transmission system, which includes one or more clutches for shifting from one of the gear ratios to another, may require rotation of at least one of an input of the transmission system or an output of the transmission system for efficient shifting from one of the gear ratios to another. In the drive system having the transmission system between the crank axle and the front sprocket, it may happen that, during movement, the driven wheel does not cause the front sprocket to rotate, e.g., with respect to a freewheel between a wheel hub and a rear sprocket. Therefore, the drive system may require the input of the transmission system to rotate for efficient shifting.In view of this, the transmission system including one or more clutches for shifting from one of the gear ratios to another may benefit from having a torque and / or speed of the input of the transmission system, or e.g., the crankshaft, higher than the predetermined threshold for efficient shifting from one of the gear ratios to another. Therefore, supplying power to the electric motor by the controller in response to receiving the shift command when a torque and / or speed of the crankshaft is below a predetermined threshold may contribute to efficient shifting.

[0012] The electric motor may drive the input of the transmission system or the output of the transmission system to provide sufficient rotation of the input of the transmission system relative to the output of the transmission system to efficiently shift from one of the gear ratios to another.

[0013] Optionally, the controller is configured to receive a signal representative of a speed of the vehicle, e.g., from a wheel speed sensor or a vehicle speed sensor. The controller may be configured to withhold power to the electric motor when the vehicle speed is below a predetermined vehicle speed threshold. Withholding power to the motor when the vehicle speed is below a predetermined vehicle speed threshold may prevent the vehicle from propelling forward when the driver unexpectedly does so. The predetermined vehicle speed threshold may be, for example, 6 km / h or, for example, 5, 4, 3, 2, or 1 km / h.Optionally, the controller is configured to override the instruction to supply power to the electric motor in response to receiving the shift command when a torque and / or a speed of the crank axle is below a predetermined threshold in the event that the vehicle speed is below the predetermined vehicle speed threshold.

[0014] Optionally, the controller is configured to control the power to the electric motor while controlling the one or more clutches to be at or below a first predetermined power threshold. The first predetermined power threshold may be, for example, 50 W or, for example, 40, 30, 20, or 10 W. Optionally, the controller is configured to control the power to the electric motor while controlling the one or more clutches to be at or above a second predetermined power threshold. The second predetermined power threshold may be, for example, 10 W or, for example, 20, 30, 40, or 50 W.

[0015] Optionally, the electric motor serves primarily to assist gear shifting. The electric motor can, for example, have a power of 50 W or less, such as 20 W or less.

[0016] Optionally, the electric motor is configured to drive the output, e.g., via the transmission system, to assist motive power. The electric motor may, for example, have a power output of 250 W or more. In example human-powered vehicles, when the electric motor is powered, the crank axle is driven by the user. When the electric motor drives the output of the drive system to assist motive power, the controller may be configured, in response to receiving the shift command, to maintain power to the electric motor when a torque and / or a speed of the crank axle is below a predetermined threshold. Optionally, the controller is configured, in response to receiving the shift command, to maintain power to the electric motor at the current power level.Optionally, the controller is configured, in response to receiving the switch command, to maintain power to the electric motor at the current power level when a torque and / or a speed of the crankshaft is below a predetermined threshold. Optionally, the controller is configured, in response to receiving the switch command, to set power to the electric motor to the first predetermined power threshold when the current power level is higher than the first predetermined power threshold. Optionally, the controller is configured, in response to receiving the switch command, to set power to the electric motor to the first predetermined power threshold when a torque and / or a speed of the crankshaft is below a predetermined threshold and when the current power level is higher than the first predetermined power threshold.Optionally, the controller is configured, in response to receiving the shift command, to set power to the electric motor to the second predetermined power threshold when the current power level is less than the second predetermined power threshold. Optionally, the controller is configured, in response to receiving the shift command, to set power to the electric motor to the second predetermined power threshold when a torque and / or a speed of the crank axle is below a predetermined threshold and when the current power level is less than the second predetermined power threshold. The controller may be configured not to increase power to the electric motor to the second predetermined power threshold when the vehicle speed is below the predetermined vehicle speed threshold.

[0017] Optionally, the drive system comprising an automatic shift command generator is configured to automatically generate a shift command and provide the shift command to the controller. The automatic shift command generator may be configured to automatically generate the shift command based on one or more of a current gear ratio, a vehicle speed, a vehicle acceleration, a crank torque and / or a crank speed, a drive power provided by a rider, a cadence, a heart rate, a breathing rate, a road gradient, or the like. The automatic shift command generator may, for example, be configured to automatically generate a shift command to maintain the cadence within a predetermined cadence interval. The automatic shift command generator may, for example,be configured to automatically generate a shift command to maintain drive power within a predetermined torque range. The automatic shift command generator and the controller may both be part of a control unit or control system.

[0018] Optionally, the drive system includes a one-way clutch between the crank axle and an input of the transmission system and / or an input shaft of the electric motor. Thus, supplying power to the electric motor does not cause the crank axle and optionally connected cranks and / or pedals to rotate.

[0019] Optionally, the drive system includes a clutch for decoupling an output of the transmission system from a wheel. The wheel is a driven wheel when coupled. The clutch may be configured, for example, to decouple an output of the transmission system from the front ring gear. The controller may then be configured to decouple the output of the transmission system from the wheel when the electric motor is powered in response to receiving a shift command when a torque and / or a speed of the crank axle is below a predetermined threshold, for example, another predetermined threshold.Thus, when a torque and / or a speed of the crank axle is below a certain threshold, for example, when the speed of the crank axle is zero or close to zero, such as during coasting, the output of the transmission system can be decoupled from the wheel so that any driving of the transmission system with the electric motor does not result in unexpected propulsion of the vehicle. The controller can be configured to control the clutch into the coupled state after the shift is completed. Thus, the clutch can prevent the vehicle from being driven by the motor during a shift of the transmission system when the crank axle is not rotating or is rotating only very slowly, e.g., when the vehicle is not moving or is moving very slowly. Thus, shifting during a standstill or, e.g., slow, coasting may be enabled.During a standstill or coasting, the rider may not notice the wheel being decoupled from the transmission system. Once the shift is complete, the wheel is recoupled to the transmission system ready for use. The controller may be configured to control the clutch to the engaged state if the crank axis rotational speed is higher than a predetermined threshold, e.g., another predetermined threshold. Thus, in the event that the rider begins pedaling while the clutch is in the decoupled state, the controller may switch the clutch to the engaged state to provide the expected resistance to pedaling for the user.

[0020] Optionally, the clutches of the transmission system are configured to shift under load. The clutches, or one or more of the clutches of the transmission system, may, for example, be similar to or identical to a clutch as described in WO2018 / 199757A2, WO2020 / 085911A2, or WO2021 / 080431A1, which are hereby incorporated by reference in their entirety.

[0021] Optionally, a rotational axis of the front sprocket is laterally offset relative to an axis of the crank axle. This allows the rotational axis of the front sprocket and the crank axle to be parallel rather than coaxial.

[0022] Optionally, the electric motor is concentric with the crank axis. Alternatively, the electric motor can be offset relative to the crank axis.

[0023] Optionally, the transmission system includes a continuously variable transmission (CVT). The CVT can be configured to operate with a variety of different discrete gear ratios. Alternatively or additionally, the transmission system can include a belt drive. Alternatively or additionally, the transmission system can include a planetary gear set.

[0024] Optionally, the drive system includes a reduction gear between the electric motor and the transmission system.

[0025] According to one aspect, a drive system for a human-powered vehicle is provided. The drive system includes a rear sprocket forming an input of the drive system for receiving human drive force. The drive system includes a hub shell forming an output of the drive system. The rear sprocket may be arranged to receive a chain. The rear sprocket may be arranged to receive a belt. Such a rear sprocket is sometimes also referred to as a pulley. The rear sprocket may be arranged to be driven by a shaft drive. The rear sprocket may be driven by a front sprocket, such as a chainring or pulley, e.g., via a chain, belt, or shaft drive. The hub shell may be rotatable about a wheel axle.The hub shell may be configured to be mounted to a driven wheel of the vehicle. The hub shell may, for example, include spoke flanges for mounting the hub shell to a wheel rim via a plurality of spokes. The drive system further includes a gear system between the input and the output. The gear system has an input connectable to the input of the drive system. The gear system has an output connectable to the output of the drive system. The gear system has a plurality of different selectable gear ratios. The gear system may have two different selectable gear ratios. Preferably, the gear system has more than two different selectable gear ratios, such as 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 different selectable gear ratios.Preferably, the drive system is free of a derailleur. The transmission system includes one or more clutches for shifting from one of the gear ratios to another. The drive system includes an electric motor connected to the transmission system. The drive system further includes a controller. The controller is configured to receive a shift command requesting a shift from one of the gear ratios to another. The shift command may, for example, be received wired or wirelessly by a receiver of the controller. The shift command may be transmitted to the controller by a shifting device. The shifting device may, for example, include one or more shift buttons or shift levers. The controller is configured to receive a signal representative of a torque and / or a rotational speed of the rear sprocket.The signal representative of a torque and / or a rotational speed of the rear sprocket may comprise a signal representative of a torque and / or a rotational speed of a front sprocket, such as a chainring, a pulley, or a cardan sprocket. The signal representative of a torque and / or a rotational speed of the rear sprocket may comprise a signal representative of a torque and / or a rotational speed of a chain, a belt, or a cardan shaft. The signal representative of a torque and / or a rotational speed of the rear sprocket may comprise a signal representative of a torque and / or a rotational speed of a crank axle. For this purpose, the drive system may include a torque sensor and / or a rotational speed sensor.The controller is configured, in response to receiving the shift command, when a torque and / or rotational speed of the rear sprocket is below a predetermined threshold, to power the electric motor and control the one or more clutches to shift from one of the gear ratios to the other. The electric motor can drive the input of the transmission system and / or the output of the transmission system to provide sufficient rotation of the input of the transmission system relative to the output of the transmission system to efficiently shift from one of the gear ratios to another.

[0026] According to one aspect, a drive system for a human-powered vehicle is provided. The drive system includes a crank axle forming an input of the drive system for receiving human drive force. The drive system includes a hub shell forming an output of the drive system. The drive system includes a rear sprocket forming an intermediate input of the drive system. The rear sprocket may be arranged to receive a chain. The rear sprocket may be arranged to receive a belt. Such a rear sprocket is sometimes also referred to as a pulley. The rear sprocket may be arranged to be driven by a shaft drive. The rear sprocket may be driven by a front sprocket, such as a chainring or pulley, e.g., via a chain, belt, or shaft drive.The hub shell may be rotatable about a wheel axle. The hub shell may be configured to be mounted to a driven wheel of the vehicle. For example, the hub shell may include spoke flanges for mounting the hub shell to a wheel rim via a plurality of spokes. The drive system further includes a gear system between the intermediate input and the output. The gear system has an input connectable to the intermediate input of the drive system. The gear system has an output connectable to the output of the drive system. The gear system has a plurality of different selectable gear ratios. The gear system may have two different selectable gear ratios.Preferably, the transmission system has more than two different selectable gear ratios, such as 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 different selectable gear ratios. Preferably, the drive system is free of a derailleur. The transmission system includes one or more clutches for switching from one of the gear ratios to another. The drive system includes an electric motor connected to the transmission system, such as a front sprocket, e.g., via the crank axle. The drive system further includes a controller. The controller is configured to receive a shift command requesting a shift from one of the gear ratios to another. The shift command may, for example, be received wired or wirelessly by a receiver of the controller. The shift command may be transmitted to the controller by a switching device. The switching device may, for example,include one or more shift buttons or shift levers. The controller is configured to receive a signal representative of a torque and / or a rotational speed of the rear sprocket. The signal representative of a torque and / or a rotational speed of the rear sprocket may include a signal representative of a torque and / or a rotational speed of a front sprocket, such as a chainring, pulley, or cardan sprocket. The signal representative of a torque and / or a rotational speed of the rear sprocket may include a signal representative of a torque and / or a rotational speed of a chain, belt, or cardan.The signal representative of a torque and / or a rotational speed of the rear sprocket may include a signal representative of a torque and / or a rotational speed of a crank axle. For this purpose, the drive system may include a torque sensor and / or a rotational speed sensor. The controller is configured, in response to receiving the shift command, when a torque and / or a rotational speed of the rear sprocket is below a predetermined threshold, to supply power to the electric motor and control the one or more clutches to shift from one of the gear ratios to the other.

[0027] It is understood that the electric motor may be powered for a predetermined period of time before the one or more clutches are controlled to shift from one of the gear ratios to the other. Alternatively, it is possible for the electric motor to be powered for a predetermined period of time after the one or more clutches have been controlled to shift from one of the gear ratios to the other. It is also possible for the electric motor to be powered simultaneously with the one or more clutches being controlled to shift from one of the gear ratios to the other.

[0028] If the signal representative of a torque and / or speed of the rear sprocket is below the predetermined threshold, this may be representative of a coasting or near-coasting situation, or a stationary or near-stationary situation. Rotating the rear sprocket with a torque and / or speed below the predetermined threshold may cause difficulties when shifting from one gear ratio to another, which may be mitigated by supplying power to the electric motor as described herein.

[0029] The signal representative of a torque and / or a rotational speed of the rear sprocket can be obtained at different locations in the vehicle. The signal representative of a torque and / or a rotational speed of the rear sprocket can be obtained, for example, by determining a signal representative of a torque and / or a rotational speed of one or more of the following: a crank arm, the crank axle, a transmission axle, a front sprocket, the rear sprocket, a chain, a drive belt, a cardan shaft, or the like. With regard to standstill or near-standstill, the signal representative of a torque and / or a rotational speed of the rear sprocket can be obtained, for example, by determining a signal representative of a torque and / or a rotational speed of a wheel or a vehicle speed.

[0030] The transmission system, which includes one or more clutches for shifting from one of the gear ratios to another, may require rotation of at least one of an input of the transmission system or an output of the transmission system for efficient shifting from one of the gear ratios to another. In the drive system having the transmission system between the rear sprocket and the hub shell, it may happen that, during movement, the driven wheel does not rotate the rear sprocket, e.g., with respect to a freewheel between a wheel hub and a rear sprocket. Therefore, the drive system may require the input of the transmission system to rotate for efficient shifting.In view of this, the transmission system including one or more clutches for shifting from one of the gear ratios to another may benefit from having a torque and / or speed of an input of the transmission system that is higher than the predetermined threshold for efficient shifting from one of the gear ratios to another. Therefore, supplying power to the electric motor by the controller in response to receiving the shift command when a torque and / or speed of the rear ring gear is below a predetermined threshold may contribute to efficient shifting. The electric motor may drive the input of the transmission system or the output of the transmission system to provide sufficient rotation of the input of the transmission system relative to the output of the transmission system for efficient shifting from one of the gear ratios to another.

[0031] Optionally, the controller is configured to receive a signal representative of a speed of the vehicle, e.g., from a wheel speed sensor or a vehicle speed sensor. The controller may be configured to withhold power to the electric motor when the vehicle speed is below a predetermined vehicle speed threshold. Withholding power to the motor when the vehicle speed is below a predetermined vehicle speed threshold may prevent the vehicle from propelling forward when the driver unexpectedly does so. The predetermined vehicle speed threshold may be, for example, 6 km / h or, for example, 5, 4, 3, 2, or 1 km / h.Optionally, the controller is configured to override the instruction to supply power to the electric motor in response to receiving the shift command when a torque and / or a speed of the rear sprocket is below a predetermined threshold in the event that the vehicle speed is below the predetermined vehicle speed threshold.

[0032] Optionally, the controller is configured to control the power to the electric motor while controlling the one or more clutches to be at or below a first predetermined power threshold. The first predetermined power threshold may be, for example, 50 W or, for example, 40, 30, 20, or 10 W. Optionally, the controller is configured to control the power to the electric motor while controlling the one or more clutches to be at or above a second predetermined power threshold. The second predetermined power threshold may be, for example, 10 W or, for example, 20, 30, 40, or 50 W.

[0033] Optionally, the electric motor serves primarily to assist gear shifting. The electric motor can, for example, have a power of 50 W or less, such as 20 W or less.

[0034] Optionally, the electric motor is configured to drive the output, e.g., via the transmission system, to assist the motive power. The electric motor may, for example, have a power output of 250 W or more. The electric motor may be positioned on the vehicle's crank, which drives the transmission system, e.g., via a chain, belt, or cardan shaft. The electric motor may be part of a crank assembly. The electric motor may be positioned on or near the vehicle's driven wheel, such as the rear wheel of a bicycle. The electric motor may be positioned within the hub shell, which drives the input or output of the transmission system. In example human-powered vehicles, when the electric motor is powered, the crank axle is driven by the user.When the electric motor drives the output of the drive system to assist the motive force, the controller may be configured, in response to receiving the shift command, to maintain power to the electric motor when a torque and / or a speed of the rear sprocket is below a predetermined threshold. Optionally, the controller is configured, in response to receiving the shift command, to maintain power to the electric motor at the current power level. Optionally, the controller is configured, in response to receiving the shift command, to maintain power to the electric motor at the current power level when a torque and / or a speed of the crank axle is below a predetermined threshold.Optionally, the controller is configured, in response to receiving the switch command, to set power to the electric motor to the first predetermined power threshold when the current power level is higher than the first predetermined power threshold. Optionally, the controller is configured, in response to receiving the switch command, to set power to the electric motor to the first predetermined power threshold when a torque and / or a speed of the crank axle is below a predetermined threshold and when the current power level is higher than the first predetermined power threshold. Optionally, the controller is configured, in response to receiving the switch command, to set power to the electric motor to the second predetermined power threshold when the current power level is lower than the second predetermined power threshold.Optionally, the controller is configured, in response to receiving the shift command, to set power to the electric motor to the second predetermined power threshold when a torque and / or a speed of the crankshaft is below a predetermined threshold and when the current power level is lower than the second predetermined power threshold. The controller may be configured not to increase power to the electric motor to the second predetermined power threshold when the vehicle speed is below the predetermined vehicle speed threshold.

[0035] Optionally, the drive system includes a one-way clutch between the rear sprocket and an input of the transmission system. Optionally, the drive system includes a one-way clutch between the electric motor and an input or output of the transmission system. Thus, supplying power to the electric motor does not cause the crank axle and optionally connected cranks and / or pedals to rotate.

[0036] Optionally, the drive system includes a clutch for decoupling an output of the transmission system from a wheel. The wheel is a driven wheel when coupled. The clutch may be configured, for example, to decouple an output of the transmission system from the hub shell. The controller may then be configured to decouple the output of the transmission system from the wheel while powering the electric motor when a torque and / or a speed of the rear sprocket and / or the crank axle is below a predetermined threshold, for example, another predetermined threshold.Thus, when a torque and / or a speed of the rear sprocket and / or the crank axle is below a certain threshold, for example, when the speed of the rear sprocket and / or the crank axle is zero or close to zero, such as during coasting, the output of the transmission system may be decoupled from the wheel so that any driving of the transmission system with the electric motor does not result in unexpected propulsion of the vehicle.

[0037] Optionally, the clutches of the transmission system are configured to shift under load. The clutches, or one or more of the clutches of the transmission system, may, for example, be similar to or identical to a clutch as described in WO2018 / 199757A2, WO2020 / 085911A2, or WO2021 / 080431A1, which are hereby incorporated by reference in their entirety.

[0038] Optionally, the electric motor is concentric with the crank axis. Alternatively, the electric motor can be offset relative to the crank axis. Optionally, the electric motor is concentric with the wheel axis.

[0039] Optionally, the transmission system is housed in a wheel hub, such as a hub shell.

[0040] Optionally, the transmission system includes a planetary gear set or a plurality of planetary gear sets.

[0041] Optionally, the transmission system includes a continuously variable transmission (CVT). The CVT can be configured to operate with a variety of different discrete gear ratios. Alternatively, or additionally, the transmission system can include a belt drive.

[0042] Optionally, the drive system includes a reduction gear between the electric motor and the transmission system.

[0043] According to one aspect, a crank assembly for a human-powered vehicle, such as a bicycle, comprising the drive system as described in this document is provided.

[0044] According to one aspect, a hub assembly for a human-powered vehicle, such as a bicycle, comprising the drive system as described in this document is provided.

[0045] According to one aspect, a human-powered vehicle, such as a bicycle, comprising the drive system as described in this document or the crank assembly as described in this document is provided.

[0046] It is understood that one or more of the above aspects, features, and options may be combined. It is understood that any of the options described with respect to one aspect may also be applied to any of the other aspects. SHORT DESCRIPTION OF THE DRAWING

[0047] The invention will be explained in more detail based on exemplary embodiments illustrated in a drawing. The exemplary embodiments are for illustrative purposes and are not restrictive. It should be noted that the figures are only schematic representations of embodiments of the invention, which serve as examples and are not restrictive.

[0048] The following applies in the drawing: Fig. 1 shows a schematic example of a drive system; Fig. 2 shows a schematic example of a drive system; Fig. 3 shows a schematic example of a drive system; Fig. 4 shows a schematic example of a drive system; Fig. 5 shows a schematic example of a drive system; Fig. 6 shows a schematic example of a drive system; and the Fig. 7A and Fig. 7B shows examples of bicycles. DETAILED DESCRIPTION

[0049] Fig. 1 shows an example of a drive system 1 for a human-powered vehicle, such as a bicycle. The drive system 1 comprises a crank axle 2, which forms an input I of the drive system 1 for receiving a human drive force. The drive system 1 comprises a front sprocket 4, which forms an output O of the drive system 1. In this example, the front sprocket 4 is a chainring arranged to receive a chain 6. Alternatively, the front sprocket can be a pulley arranged to receive a belt, or the front sprocket can be arranged to drive a shaft drive.

[0050] In this example, the drive system 1 further comprises a transmission system 8 between the input I and the output O. The transmission system 8 has a plurality of different selectable gear ratios. The transmission system 8 includes one or more clutches 10 for switching from one of the gear ratios to another. Here, the drive system 1 includes an electric motor 12. In this example, the electric motor is connected to the transmission system 8, here to an input A of the transmission system 8. The drive system further includes a controller 14. The controller 14 is configured to receive a shift command requesting a shift from one of the gear ratios to another. The shift command can be received, for example, wired or wirelessly by a receiver 14A of the controller. The shift command can be transmitted to the controller 14 by a switching device 16. The switching device 16 can, for example,include one or more gearshift knobs or levers.

[0051] Optionally, the drive system comprising an automatic shift command generator 16A is configured to automatically generate a shift command and provide the shift command to the controller 14. The automatic shift command generator 16A may be configured to automatically generate the shift command based on one or more of a current gear ratio, a vehicle speed, a vehicle acceleration, a crank torque and / or a crank speed, a drive power provided by a rider, a cadence, a heart rate, a breathing rate, a road gradient, or the like. The automatic shift command generator may, for example, be configured to automatically generate a shift command to maintain the cadence within a predetermined cadence interval. The automatic shift command generator may, for example,be configured to automatically generate a shift command to maintain drive power within a predetermined torque range. The automatic shift command generator and the controller may both be part of a control unit or control system.

[0052] In this example, the drive system 8 includes a torque sensor 17 and / or a crankshaft rotational speed sensor 18. The controller 14 is configured to receive a signal representative of a torque and / or a rotational speed of the crankshaft, here from one or both of the sensors 17, 18. In this example, the controller is configured, in response to receiving the shift command, when a torque and / or a rotational speed of the crankshaft 2 is below a predetermined threshold, to supply power to the electric motor 12 and control the one or more clutches 10 to shift from one of the gear ratios to the other.

[0053] In this example, the controller 14 is configured to receive a signal representative of a speed of the vehicle, here from a wheel speed sensor 20 or a vehicle speed sensor 22. The controller 14 is configured in this example to not supply power to the electric motor 12 when the vehicle speed is below a predetermined vehicle speed threshold. Disabling power to the motor when the vehicle speed is below a predetermined vehicle speed threshold may prevent the vehicle from propelling forward when the driver unexpectedly does so.The controller 14 may override the instruction to supply power to the electric motor 12 in response to receiving the shift command when a torque and / or a speed of the crank axle is below a predetermined threshold in the event that the vehicle speed is below the predetermined vehicle speed threshold.

[0054] Optionally, the controller is configured to control the power to the electric motor while controlling the one or more clutches to be at or below a first predetermined power threshold. The first predetermined power threshold may be, for example, 100 W or, for example, 50 W or, for example, 40, 30, 20, or 10 W. Optionally, the controller is configured to control the power to the electric motor while controlling the one or more clutches to be at or above a second predetermined power threshold. The second predetermined power threshold may be, for example, 10 W or, for example, 20, 30, 40, 50, or 100 W.

[0055] In this example, the electric motor 12 is configured to drive the output O to assist the driving force. Here, the electric motor 12 drives the output O via the transmission system 8. Here, when the crank axle 2 is driven by the user, the electric motor 12 drives the output. Here, the controller 14 is configured, in response to receiving the shift command, to maintain power to the electric motor 12 when it is supplied with power, e.g., even when a torque and / or a speed of the crank axle 2 is below a predetermined threshold. The controller 14 may be configured, in response to receiving the shift command, to maintain power to the electric motor 12 at the current power level. The controller 14 may be configured, in response to receiving the shift command, to set power to the electric motor 12 to the first predetermined power threshold, e.g.,when the current power level is higher than the first predetermined power threshold, e.g., when a torque and / or a speed of the crankshaft is below a predetermined threshold. The controller 14 may be configured, in response to receiving the shift command, to set power to the electric motor 12 to the second predetermined power threshold, e.g., when the current power level is lower than the second predetermined power threshold, e.g., when a torque and / or a speed of the crankshaft is below a predetermined threshold. The controller 14 may be configured not to increase power to the electric motor 12 to the second predetermined power threshold when the vehicle speed is below the predetermined vehicle speed threshold.

[0056] Fig. Figure 2 shows an example of a drive system 1 for a muscle-powered vehicle, similar to the drive system 1 shown in Fig. 1. In this example, the drive system 1 includes a one-way clutch 24 between the crank axle 2 and an input A of the transmission system 8. Here, the one-way clutch 24 is also located between the crank axle 2 and a rotor 26 of the electric motor 12. Thus, supplying the electric motor 12 with power does not cause the crank axle 2 and optionally connected cranks and / or pedals to rotate.

[0057] Fig. 3 shows an example of a drive system 1. In this example, the transmission system 8 includes a first transmission 100, which in this example is operable according to two different gear ratios. It is understood that the first transmission 100 can alternatively be operable according to only one gear ratio or according to more than two gear ratios. To shift between the two gear ratios, the first transmission 100 includes a first actuatable clutch C1, in this example a load-shifting clutch. The first transmission 100 here has two parallel transmission paths. Here, the first transmission path includes the first actuatable clutch C1. Furthermore, the first transmission path here includes a first cooperating gear pair R1 comprising a primary gear rotatable about the first axis A1 and a secondary gear rotatable about the second axis A2.In this example, the second transmission path includes a first freewheel V1 and a second cooperating gear pair R2, which includes a primary gear rotatable about the first axis A1 and a secondary gear rotatable about the second axis A2. Here, each primary gear of the first transmission 100 is mounted on the first crank axis 2. The first freewheel V1 is associated with the first axis A1 in this example. Each secondary gear of the first transmission 100 is rotatable about the stationary second axis 48.

[0058] The second transmission 200, in this example, is also operable according to two different gear ratios. It should be understood that the second transmission 200 may alternatively be operable according to only one gear ratio or according to more than two gear ratios. To shift between the two gear ratios, the second transmission 200 includes a second actuatable clutch C2, in this example a load-shifting clutch. The second transmission 200 here has two parallel transmission paths, namely a third transmission path and a fourth transmission path. Here, the third transmission path includes a second actuatable clutch C2. Furthermore, the third transmission path here includes a third cooperating gear pair R3, which includes a primary gear rotatable about the second axis A2 and a secondary gear rotatable about the first axis A1.In this example, the fourth transmission path includes a second freewheel V2 and a fourth cooperating gear pair R4, which includes a primary gear rotatable about the second axis A2 and a secondary gear rotatable about the first axis A1. Here, each secondary gear of the second transmission 200 is mounted on the first crank axle 2. Here, each primary gear of the second transmission 200 is rotatable about the stationary second axis 48.

[0059] The first and second actuatable clutches C1 and C2 can be used to select an appropriate transmission path between the transmission input I and the transmission output O. More specifically, the first actuatable clutch C1 can be used to selectively switch between the first transmission path and the second transmission path of the first transmission 100, and the second actuatable clutch C2 can be used to selectively switch between the third transmission path and the fourth transmission path of the second transmission 200.

[0060] In this example, an optional third freewheel VB1 is provided in the first transmission path in series with the first actuatable clutch C1. Similarly, in this example, an optional fourth freewheel VB2 is provided in the third transmission path in series with the second actuatable clutch C2. In this example, the fourth freewheel VB2 is assigned to the first axle A1.

[0061] In this example, a first gear stage is formed by a selective one of the first cooperating gear pair R1 or the second cooperating gear pair R2; a second gear stage is formed by a selective one of the third cooperating gear pair R3 or the fourth cooperating gear pair R4.

[0062] In this example, the drive system 1 further comprises a third planetary gear 300, which provides a third gear stage. The third planetary gear is assigned to the second axis A2. The third planetary gear 300 comprises a planetary gear set 305, which has three rotating elements, in particular a ring gear 310, a planet carrier 320 carrying one or more planet gears 330, and a sun gear 340. One of the rotating elements is non-rotatably attached to a stationary part of the drive system 1, here the stationary axis 48, which extends along the second axis A2. In this example, the sun gear 340 is attached to the stationary axis 48.

[0063] In this example, the third planetary gear set 300 includes a third actuatable clutch C3 and a fourth actuatable clutch C4. Alternatively, the third planetary gear set 300 can include either the third actuatable clutch C3 or the fourth actuatable clutch C4. The third actuatable clutch C3 is arranged on an input side of the planetary gear set, and the fourth actuatable clutch C4 is arranged on an output side of the planetary gear set. In particular, the third actuatable clutch C3 is arranged in a transmission path between an input of the third planetary gear set and the planet carrier 320. The fourth actuatable clutch C4 is arranged in a transmission path between the ring gear 310 and an output of the third planetary gear set. A fifth freewheel V3 is arranged in a transmission path between the input of the third planetary gear set and the ring gear 310.A sixth freewheel V4 is arranged in a transmission path between the planet carrier 320 and the output of the third planetary gear set. An optional seventh freewheel VB3 is arranged in series with the third actuatable clutch C3. Furthermore, an optional eighth freewheel VB4 is arranged in series with the fourth actuatable clutch C4.

[0064] In this example, the transmission system 8 includes four actuatable clutches, namely the first actuatable clutch C1, the second actuatable clutch C2, the third actuatable clutch C3, and the fourth actuatable clutch C4, which are connected in series. Furthermore, in this example, the first actuatable clutch C1, the second actuatable clutch C2, the third actuatable clutch C3, and the fourth actuatable clutch C4 are identical.

[0065] Each of the first, second, third, and fourth actuatable clutches C1, C2, C3, C4 is configured to be selectively in a closed state or an open state. In the closed state, the actuatable clutch couples the clutch input to the clutch output to transmit torque through the clutch, and in the open state, the clutch input is decoupled from the clutch output to not transmit torque through the clutch. Here, the first, second, third, and fourth actuatable clutches C1, C2, C3, C4 are identical. Furthermore, here, the first, second, third, and fourth actuatable clutches C1, C2, C3, C4 are associated with the second axis. Each of the clutches has one or more clutch elements rotatable about the second axis. The first axis, in this example, has no actuatable clutches associated with it and is thus devoid of actuatable clutches.In this example, each actuatable clutch is a clutch as described in WO2018 / 199757A2, WO2020 / 085911A2 or WO2021 / 080431A1.

[0066] When the first actuatable clutch C1 is engaged, torque can be transmitted through the first transmission path via the first interacting gear pair R1 from the first transmission input to the first transmission output. The first freewheel V1 is exceeded when the first actuatable clutch is engaged. When the first actuatable clutch C1 is engaged, torque can be transmitted through the second transmission path via the first freewheel and via the second interacting gear pair R2 from the first transmission input to the first transmission output. Likewise, when the second actuatable clutch C2 is engaged, torque can be transmitted through the third transmission path via the third interacting gear pair R3 from the second transmission input to the second transmission output.The second actuatable clutch C2, in the open state, enables torque to be transmitted from the second transmission input to the second transmission output through the fourth transmission path via the second freewheel V2 and via the fourth cooperating gear pair R4.

[0067] When the third actuatable clutch C3 is closed, torque can be transmitted via the third actuatable clutch C3 from the input of the third planetary gear set to the planet carrier 320. The planet carrier can deliver the torque to the ring gear 310 according to a predefined gear ratio. Thus, the fifth one-way clutch V3 can be exceeded when the third actuatable clutch C3 is closed. When the third actuatable clutch C3 is open, no torque can be transmitted via the third actuatable clutch C3 from the input 301 of the third planetary gear set to the planet carrier. Instead, when the third actuatable clutch C3 is open, torque can be transmitted via the fifth one-way clutch V3 from the input 301 of the third planetary gear set to the ring gear 310.

[0068] Furthermore, when the fourth actuatable clutch C4 is closed, torque can be transmitted via the third actuatable clutch C3 from the ring gear 310 to the output 302 of the third planetary gear set. The sixth freewheel V4 can be exceeded when the fourth actuatable clutch C4 is closed. When the fourth actuatable clutch C4 is open, no torque can be transmitted via the fourth actuatable clutch C4. Instead, when the fourth actuatable clutch C4 is open, torque can be transmitted via the sixth freewheel V4 from the planet carrier 320 to the output 302 of the third planetary gear set.

[0069] The exemplary third planetary gear set 300 is accordingly selectively operable according to three different gear ratios, here a speed-reducing gear ratio, a uniform gear ratio, and a speed-increasing gear ratio. The speed-increasing and speed-reducing gear ratios can be inverse to each other. The third gear stage selectively comprises one of the various gear ratios of the third gear set 300.

[0070] The drive system 1 further comprises a housing 49. The housing 49 contains the first gear 100 and the second gear 200.

[0071] The housing 49 may further include any additional gear arranged between the first gear 100 and the second gear 200, such as the third planetary gear 300 in this example.

[0072] Optionally, a rotational axis of the front sprocket is laterally offset relative to an axis of the crank axle. This allows the rotational axis of the front sprocket and the crank axle to be parallel rather than coaxial.

[0073] In some examples, the electric motor is concentric with the crank axis. Alternatively, the electric motor can be offset relative to the crank axis.

[0074] Optionally, the transmission system includes a continuously variable transmission (CVT). The CVT can be configured to operate with a variety of different discrete gear ratios. Alternatively or additionally, the transmission system can include a belt drive. Alternatively or additionally, the transmission system can include a planetary gear set.

[0075] Optionally, the drive system includes a reduction gear between the electric motor and the transmission system.

[0076] Fig. 4 shows an example of a drive system 1 for a human-powered vehicle, such as a bicycle. The drive system 1 comprises a sprocket 40 forming an input I of the drive system 1 for receiving a human drive force. The sprocket 40 may be a rear sprocket. The sprocket 40 may be part of a plurality of sprockets, e.g., a cassette. In this example, the sprocket 40 is arranged to receive a chain 6. Alternatively, the sprocket 40 may be a pulley arranged to receive a belt, or the sprocket may be arranged to be driven by a cardan drive. Here, the sprocket 4 is mounted on a driver 45. The drive system 1 comprises a hub shell 41 forming an output O of the drive system 1. The hub shell 41 is configured, in this example, to be mounted on a driven wheel of the vehicle.The hub shell 41 here spoke flanges 42 for mounting the hub shell 41 to a wheel rim via a plurality of spokes.

[0077] In this example, the drive system 1 further comprises a transmission system 8 between the input I and the output O. The transmission system 8 has a plurality of different selectable gear ratios. The transmission system 8 includes one or more clutches 10 for switching from one of the gear ratios to another. The ring gear 40 is connected to an input A of the transmission system 8. Here, the driver 45 is connected to the input A of the transmission system 8 via a freewheel 46. An output B of the transmission system is connected to the output O of the drive system. Here, to the hub shell 41.

[0078] Here, the drive system 1 includes an electric motor 12. In this example, the electric motor is connected to the transmission system 8, here to input A of the transmission system 8. In this example, a stator 12S of the motor 12 is non-rotatably connected to a wheel axle 44. In this example, a rotor 12R of the motor 12 is connected to input A of the transmission system, here via an optional freewheel 43.

[0079] The drive system 1 further includes a controller 14. The controller 14 is configured to receive a shift command requesting a shift from one of the gear ratios to another. The shift command can be received, for example, wired or wirelessly by a receiver 14A of the controller. The shift command can be transmitted to the controller 14 by a shift device 16. The shift device 16 can, for example, include one or more shift buttons or shift levers. Optionally, the drive system, comprising an automatic shift command generator 16A, is configured to automatically generate a shift command and provide the shift command to the controller 14, as described with regard to Fig. 1 described.

[0080] In this example, the drive system 8 includes a torque sensor 17 and / or a sprocket rotational speed sensor and / or a crank axis rotational speed sensor 18. The controller 14 is configured to receive a signal representative of a torque and / or a rotational speed of the sprocket, here from one or both of the sensors 17, 18. The signal representative of a torque and / or a rotational speed of the sprocket may include a signal representative of a torque and / or a rotational speed of the crank axis.In this example, in response to receiving the shift command, when a torque and / or speed of the ring gear 40 is below a predetermined threshold, the controller 14 is configured to supply power to the electric motor 12 and control the one or more clutches 10 to shift from one of the gear ratios to the other.

[0081] In this example, the controller 14 is configured to receive a signal representative of a speed of the vehicle, here from a wheel speed sensor 20 or a vehicle speed sensor 22. The controller 14 is configured in this example to not supply power to the electric motor 12 when the vehicle speed is below a predetermined vehicle speed threshold. Disabling power to the motor when the vehicle speed is below a predetermined vehicle speed threshold may prevent the vehicle from propelling forward when the driver unexpectedly does so.The controller 14 may override the instruction to supply power to the electric motor 12 in response to receiving the shift command when a torque and / or a speed of the ring gear 40 is below a predetermined threshold in the event that the vehicle speed is below the predetermined vehicle speed threshold.

[0082] Optionally, the controller 14 is configured to control the power to the electric motor while controlling the one or more clutches to be at or below a first predetermined power threshold. The first predetermined power threshold may be, for example, 100 W or, for example, 50 W or, for example, 40, 30, 20, or 10 W. Optionally, the controller 14 is configured to control the power to the electric motor while controlling the one or more clutches to be at or above a second predetermined power threshold. The second predetermined power threshold may be, for example, 10 W or, for example, 20, 30, 40, 50, or 100 W.

[0083] In this example, the electric motor 12 is configured to drive the output O to assist the driving force. Here, the electric motor 12 drives the output O via the gear system 8. Here, when the crank axle 2 is driven by the user, the sprocket 40 is driven, e.g., by a chain connected to a front sprocket 4 and the rear sprocket 40, and the electric motor 12 drives the output. Here, the controller 14 is configured, in response to receiving the shift command, to maintain power to the electric motor 12 when it is being powered, e.g., even when a torque and / or speed of the sprocket 40 is below a predetermined threshold. The controller 14 may be configured, in response to receiving the shift command, to maintain power to the electric motor 12 at the current power level.The controller 14 may be configured, in response to receiving the shift command, to set power to the electric motor 12 to the first predetermined power threshold, e.g., when the current power level is higher than the first predetermined power threshold, e.g., when a torque and / or a speed of the ring gear 40 is below a predetermined threshold. The controller 14 may be configured, in response to receiving the shift command, to set power to the electric motor 12 to the second predetermined power threshold, e.g., when the current power level is lower than the second predetermined power threshold, e.g., when a torque and / or a speed of the rear ring gear is below a predetermined threshold.The controller 14 may be configured not to increase the power to the electric motor 12 to the second predetermined power threshold when the vehicle speed is below the predetermined vehicle speed threshold.

[0084] Fig. Figure 5 shows an example of a drive system 1 for a muscle-powered vehicle, such as a bicycle, similar to the drive system shown in Fig. 4. In this example, the drive system includes a clutch 47 for decoupling the output B of the transmission system 8 from the output O of the drive system. Here, the clutch 47 is configured to decouple the output B of the transmission system 8 from the hub shell 41. Here, the clutch 47 is configured to decouple the output B of the transmission system 8 from the wheel. The controller 14 is configured to control the clutch 47 to the decoupled state when the electric motor is supplied with power in response to receiving a shift command when a torque and / or a speed of the ring gear 40 is below a predetermined threshold. In particular, the controller 14 may be configured to control the clutch 47 to the decoupled state when the electric motor is supplied with power in response to receiving a shift command when a torque and / or a speed of the crank axle is zero or near zero, e.g.when the vehicle speed is zero or near zero. The controller 14 may be configured to control the clutch 47 to the coupled state after the shift is completed. Thus, the clutch 47 may prevent the vehicle from being driven by the engine during a shift of the transmission system when the crank axle is not rotating or is rotating only very slowly, e.g., when the vehicle is not moving or is moving very slowly. Thus, shifting may be enabled during a standstill or, e.g., slow coasting. During a standstill or coasting, the decoupling of the wheel from the transmission system may not be noticed by a driver. Once the shift is completed, the wheel is recoupled to the transmission system ready for use.The controller 14 may be configured to control the clutch 47 to the engaged state when the crank axis rotational speed is higher than a predetermined threshold. Thus, in the event that the rider begins pedaling while the clutch 47 is in the disengaged state, the controller 14 may switch the clutch 47 to the engaged state to provide the expected resistance to the user's pedaling.

[0085] It is understood that the coupling 47 between the output of the transmission system and the output of the drive system is also shown in the examples from the Fig. 1-3 can be applied. The clutch 47 can then control the output of the transmission system from the front gear 4 in a similar manner as with respect to Fig. 5. It is understood that the coupling 47 in the example from the Fig. 1-3 can also be positioned to decouple the output of the transmission system from the wheel. For this purpose, the clutch 47 can be positioned, for example, in a wheel hub of the driven wheel, e.g., between the driver and the hub shell. The clutch 47 between the output of the transmission system and the output of the drive system can, in the example from Fig. 6 can also be applied.

[0086] Fig. Figure 6 shows an example of a drive system 1 for a human-powered vehicle, such as a bicycle. The drive system 1 comprises a crank axle 2, which forms an input I of the drive system 1 for receiving a human drive force. The drive system 1 comprises a front sprocket 4. In this example, the front sprocket 4 is a chainring arranged to receive a chain 6. Alternatively, the front sprocket may be a pulley arranged to receive a belt, or the front sprocket may be arranged to drive a shaft drive.

[0087] The drive system 1 further comprises a rear sprocket 40. The rear sprocket 40 is driven by the chain 6 and forms an intermediate input of the drive system. The sprocket 40 can be part of a plurality of sprockets, e.g., a cassette. Here, the sprocket 4 is mounted on a driver 45. The drive system 1 comprises a hub shell 41, which forms an output O of the drive system 1. In this example, the hub shell 41 is configured to be mounted on a driven wheel of the vehicle. The hub shell 41 here has spoke flanges 42 for mounting the hub shell 41 to a wheel rim via a plurality of spokes.

[0088] In this example, the drive system 1 further comprises a transmission system 8 between the input I and the output O. The transmission system 8 is housed here in the hub shell 41. The transmission system 8 has a plurality of different selectable gear ratios. The transmission system 8 includes one or more clutches 10 for switching from one of the gear ratios to another. The ring gear 40 is connected to an input A of the transmission system 8. Here, the driver 45 is connected to the input A of the transmission system 8 via a freewheel 46. An output B of the transmission system is connected to the output O of the drive system. Here, to the hub shell 41.

[0089] Here, the drive system 1 includes an electric motor 12. In this example, the electric motor 12 is connected to the front ring gear 4. The electric motor can be directly connected to the front ring gear. The electric motor can be connected to the front ring gear via the crankshaft 2. The electric motor can be connected to the front ring gear via a freewheel. In this example, the crank axle 2 is connected to the front ring gear via an optional freewheel 50. Here, the electric motor is housed in a crankcase 52. In this example, a stator 12S of the motor 12 is non-rotatably connected to the crankcase 52. In this example, a rotor 12R of the motor 12 is connected to the front ring gear 4.

[0090] The drive system 1 further includes a controller 14. The controller 14 is configured to receive a shift command requesting a shift from one of the gear ratios to another. The shift command can be received, for example, wired or wirelessly by a receiver 14A of the controller. The shift command can be transmitted to the controller 14 by a shift device 16. The shift device 16 can, for example, include one or more shift buttons or shift levers. Optionally, the drive system, comprising an automatic shift command generator 16A, is configured to automatically generate a shift command and provide the shift command to the controller 14, as described with regard to Fig. 1 described.

[0091] In this example, the drive system 8 includes a torque sensor 17 and / or a sprocket rotational speed sensor and / or a crank axle rotational speed sensor 18. The controller 14 is configured to receive a signal representative of a torque and / or a rotational speed of the rear sprocket 40, here from one or both of the sensors 17, 18. The signal representative of a torque and / or a rotational speed of the rear sprocket may include a signal representative of a torque and / or a rotational speed of any of the crank axle 2, the front sprocket 4, the chain 6, the driver 45, and / or an axle of the transmission system 8.In this example, in response to receiving the shift command, when a torque and / or speed of the rear ring gear 40 is below a predetermined threshold, the controller 14 is configured to power the electric motor 12 and control the one or more clutches 10 to shift from one of the gear ratios to the other.

[0092] In this example, the controller 14 is configured to receive a signal representative of a speed of the vehicle, here from a wheel speed sensor 20 or a vehicle speed sensor 22. The controller 14 is configured in this example to not supply power to the electric motor 12 when the vehicle speed is below a predetermined vehicle speed threshold. Disabling power to the motor when the vehicle speed is below a predetermined vehicle speed threshold may prevent the vehicle from propelling forward when the driver unexpectedly does so.The controller 14 may override the instruction to supply power to the electric motor 12 in response to receiving the shift command when a torque and / or a speed of the ring gear 40 is below a predetermined threshold in the event that the vehicle speed is below the predetermined vehicle speed threshold.

[0093] Optionally, the controller 14 is configured to control the power to the electric motor while controlling the one or more clutches to be at or below a first predetermined power threshold. The first predetermined power threshold may be, for example, 100 W or, for example, 50 W or, for example, 40, 30, 20, or 10 W. Optionally, the controller 14 is configured to control the power to the electric motor while controlling the one or more clutches to be at or above a second predetermined power threshold. The second predetermined power threshold may be, for example, 10 W or, for example, 20, 30, 40, 50, or 100 W.

[0094] In this example, the electric motor 12 is configured to drive the output O to assist the driving force. Here, the electric motor 12 drives the output O via the transmission system 8. Here, when the crank axle 2 is driven by the user, the rear sprocket 40 is driven, e.g., by a chain connected to a front sprocket 4 and the rear sprocket 40, and the electric motor 12 drives the front sprocket 4. Here, the controller 14 is configured, in response to receiving the shift command, to maintain power to the electric motor 12 when it is being powered, e.g., even when a torque and / or speed of the rear sprocket 40 is below a predetermined threshold. The controller 14 may be configured, in response to receiving the shift command, to maintain power to the electric motor 12 at the current power level.The controller 14 may be configured, in response to receiving the shift command, to set power to the electric motor 12 to the first predetermined power threshold, e.g., when the current power level is higher than the first predetermined power threshold, e.g., when a torque and / or a speed of the rear sprocket 40 is below a predetermined threshold. The controller 14 may be configured, in response to receiving the shift command, to set power to the electric motor 12 to the second predetermined power threshold, e.g., when the current power level is lower than the second predetermined power threshold, e.g., when a torque and / or a speed of the rear sprocket is below a predetermined threshold.The controller 14 may be configured not to increase the power to the electric motor 12 to the second predetermined power threshold when the vehicle speed is below the predetermined vehicle speed threshold.

[0095] In general, and particularly with regard to all of the examples, the controller 14 may be configured to stop supplying power to the electric motor once the shift is completed. To this end, the drive system may include one or more sensors for detecting the completion of the shift. In the case where the electric motor is used to assist motive power, the controller 14 may be configured to return (or maintain) power to the electric motor to the pre-shift level.

[0096] The Fig. 7A and Fig. 7B show a bicycle 100 as an example of a human-powered vehicle. The bicycle 100 includes a frame 102 with a front fork 105 and a rear fork 107, as well as a front wheel 111 and a rear wheel 113 located in the front and rear forks, respectively. The bicycle 100 further includes a crank 117 and a front sprocket 4. The bicycle 100 also includes a rear sprocket 121, for example, one or more rear sprockets, such as a cassette. A chain 6 is wound over the front sprocket 119 and the rear sprocket 121 (any of the rear sprockets 121).

[0097] In the example from Fig. 7A, the bicycle comprises a drive system 1 as shown in the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 or Fig. 6 shown.

[0098] In the example from Fig. 7B, the bicycle comprises a drive system 1 in which an axis of rotation of the front sprocket is laterally offset relative to an axis of the crank axle.

[0099] The bicycle 100 from the Fig. 7A, Fig. 7B also includes a switching device 16, which is connected here to a handlebar 131. In this example, the switching device includes an interface element, such as a button, lever, ring, or the like. The bicycle 100 also includes the controller 14.

[0100] In this specification, the invention is described with reference to specific examples of embodiments of the invention. However, it will be apparent that various modifications and changes may be made thereto without departing from the spirit of the invention. For the purpose of clarity and concise description, features are described in this specification as part of the same or separate embodiments; however, alternative embodiments are also contemplated that include combinations of all or some of the features described in these separate embodiments.

[0101] In the claims, reference signs placed in parentheses are not to be interpreted as limiting the claim. The word "comprising" does not exclude the presence of features or steps other than those recited in a claim. Furthermore, the words "a" and "an" are not to be interpreted as being limited to "only one" but are instead used to mean "at least one" and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of those measures cannot be used to advantage. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] WO 2018 / 199757A2 [0020, 0037, 0065] WO 2020 / 085911A2 [0020, 0037, 0065] WO 2021 / 080431A1 [0020, 0037, 0065]

Claims

[1] Drive system for a human-powered vehicle, comprising: a crank axle forming an input of the drive system for receiving a human driving force, and a front sprocket forming an output of the drive system, or a rear sprocket forming an input of the drive system for receiving a human driving force, and a hub shell forming an output of the drive system; a transmission system between the input and the output, the transmission system having a plurality of different selectable gear ratios and having one or more clutches for switching from one of the gear ratios to another; an electric motor connected to the drive system; and a controller configured to: Receiving a shift command requesting a shift from one of the gear ratios to another, Receiving a signal representative of a torque and / or a speed of the crank axle or the rear sprocket, in response to receiving the shift command, when a torque and / or a speed of the crankshaft or the rear sprocket is below a predetermined threshold, supplying power to the electric motor and Controlling the one or more clutches to shift from one of the gear ratios to the other. [2] Drive system for a muscle-powered vehicle, for example according to claim 1, comprising: a crank axle forming an input of the drive system for receiving a human driving force; a front sprocket forming an output of the drive system; a transmission system between the input and the output, the transmission system having a plurality of different selectable gear ratios and having one or more clutches for switching from one of the gear ratios to another; an electric motor connected to the transmission system; and a controller configured to: Receiving a shift command requesting a shift from one of the gear ratios to another, Receiving a signal representative of a torque and / or a speed of the crank axle, in response to receiving the switching command, when a torque and / or a speed of the crankshaft is below a predetermined threshold, supplying power to the electric motor and Controlling the one or more clutches to shift from one of the gear ratios to the other. [3] A drive system according to claim 1 or 2, wherein the controller is configured to: Receiving a signal representative of a speed of the vehicle, and Not supplying power to the electric motor when the vehicle speed is below a predetermined vehicle speed threshold. [4] The drive system of claim 1, 2 or 3, wherein the controller is configured to control the power to the electric motor while controlling the one or more clutches to be at or below a first predetermined power threshold. [5] The drive system of any of claims 1-4, wherein the controller is configured to control the power to the electric motor while controlling the one or more clutches to be at or above a second predetermined power threshold. [6] The drive system of any of claims 1-5, wherein the electric motor is configured to drive the input. [7] A drive system according to any one of claims 1-6, wherein the electric motor is configured to drive the output to assist the driving force. [8] The drive system of claim 6 or 7, wherein the controller is configured to maintain power to the electric motor in response to receiving the shift command. [9] The drive system of any of claims 1-8, wherein the controller is configured to, in response to receiving the switching command, set power to the electric motor to the first predetermined power threshold when the present power level is higher than the first predetermined power threshold. [10] The drive system of any of claims 1-9, wherein the controller is configured to, in response to receiving the switching command, set power to the electric motor to the second predetermined power threshold when the present power level is lower than the second predetermined power threshold. [11] A drive system according to any one of claims 1-9, comprising an automatic shift command generator configured to automatically generate a shift command and provide the shift command to the controller. [12] Drive system according to one of claims 1-11, comprising a one-way clutch between the crank axle and an input of the transmission system and / or an input axle of the electric motor. [13] A drive system according to any one of claims 1-12, comprising a clutch for decoupling an output of the transmission system from a wheel, wherein the controller is configured to decouple the output of the transmission system from the wheel when the electric motor is powered in response to receiving a shift command when a torque and / or a speed of the crank axle is below a predetermined threshold. [14] A drive system according to any one of claims 1-13, wherein the clutches of the transmission system are configured to shift under load. [15] Drive system according to one of claims 1-14, wherein an axis of rotation of the front sprocket is laterally offset relative to an axis of the crank axis. [16] Drive system according to one of claims 1-15, wherein the electric motor is concentric with the crank axis. [17] Drive system according to any one of claims 1-16, wherein the electric motor is offset relative to the crank axis. [18] A drive system according to any one of claims 1-17, wherein the transmission system includes a continuously variable transmission. [19] A drive system according to any one of claims 1-18, wherein the transmission system includes a belt drive. [20] A drive system according to any one of claims 1-19, including a reduction gear between the electric motor and the transmission system. [21] Drive system for a muscle-powered vehicle, for example according to claim 1, comprising: a rear sprocket forming an input of the drive system for receiving a human driving force; a hub shell forming an output of the drive system; a transmission system between the input and the output, the transmission system having a plurality of different selectable gear ratios and having one or more clutches for switching from one of the gear ratios to another; an electric motor connected to the transmission system; and a controller configured to: Receiving a shift command requesting a shift from one of the gear ratios to another, Receiving a signal representative of a torque and / or a speed of the rear sprocket, in response to receiving the shift command, when a torque and / or a speed of the rear sprocket is below a predetermined threshold, supplying power to the electric motor and Controlling the one or more clutches to shift from one of the gear ratios to the other. [22] Drive system for a muscle-powered vehicle, for example according to claim 1, comprising: a crank axle forming an input of the drive system for receiving a human driving force; a hub shell forming an output of the drive system; a rear sprocket that forms an intermediate entrance a transmission system between the intermediate input and the output, the transmission system having a plurality of different selectable gear ratios and having one or more clutches for switching from one of the gear ratios to another; an electric motor connected to the one front sprocket; and a controller configured to: Receiving a shift command requesting a shift from one of the gear ratios to another, Receiving a signal representative of a torque and / or speed of a rear sprocket, in response to receiving the shift command, when a torque and / or a speed of the rear sprocket is below a predetermined threshold, supplying power to the electric motor and Controlling the one or more clutches to shift from one of the gear ratios to the other. [23] A drive system according to claim 21 or 22, wherein the controller is configured to: Receiving a signal representative of a speed of the vehicle, and Not supplying power to the electric motor when the vehicle speed is below a predetermined vehicle speed threshold. [24] The drive system of claim 21, 22 or 23, wherein the controller is configured to control the power to the electric motor during the control of the one or more clutches to be at or below a first predetermined power threshold. [25] A drive system according to any one of claims 21-24, wherein the controller is configured to control the power to the electric motor during the control of the one or more clutches to be at or above a second predetermined power threshold. [26] A drive system according to any one of claims 21-25, wherein the electric motor is configured to assist the driving force. [27] The drive system of claim 26, wherein the controller is configured to maintain power to the electric motor in response to receiving the shift command. [28] The drive system of any of claims 21-27, wherein the controller is configured to, in response to receiving the switching command, set power to the electric motor to the first predetermined power threshold when the present power level is higher than the first predetermined power threshold. [29] The drive system of any of claims 21-28, wherein the controller is configured to, in response to receiving the switching command, set power to the electric motor to the second predetermined power threshold when the present power level is lower than the second predetermined power threshold. [30] A drive system according to any one of claims 21-29, comprising an automatic shift command generator configured to automatically generate a shift command and provide the shift command to the controller. [31] Drive system according to one of claims 21-30, comprising a one-way clutch between the rear gear ring and an input of the transmission system and / or comprising a one-way clutch between the electric motor and an input or output of the transmission system. [32] A drive system according to any one of claims 21-31, comprising a clutch for decoupling an output of the transmission system from a wheel, wherein the controller is configured to decouple the output of the transmission system from the wheel when the electric motor is powered in response to receiving a shift command when a torque and / or a speed of the crank axle is below a predetermined threshold. [33] A drive system according to any one of claims 21-32, wherein the clutches of the transmission system are configured to shift under load. [34] A drive system according to claim 21 or any of claims 23-33 when dependent on claim 21, wherein the electric motor is concentric with a wheel axle. [35] A drive system according to claim 22 or any of claims 23-33 when dependent on claim 22, wherein the electric motor is concentric with the crank axis or offset relative to the crank axis. [36] Drive system according to one of claims 21-35, wherein the transmission system includes a planetary gear set and / or a continuously variable transmission. [37] A drive system according to any one of claims 21-36, including a reduction gear between the electric motor and the transmission system. [38] A crank assembly for a human-powered vehicle comprising the drive system according to any one of claims 1-20 or claim 22 or any one of claims 23-27 when dependent on claim 23. [39] A hub assembly for a human-powered vehicle comprising the drive system of claim 21 or 22 or any of claims 23-37 when dependent on claim 22. [40] A human-powered vehicle comprising the drive system according to any one of claims 1-37 or the crank assembly according to claim 38 and / or the hub assembly according to claim 39.

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